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Influence of layer thickness and growth temperature on in-field Jc in BaZrO3/YBa2Cu3Oy quasi-multilayered films
NASA Astrophysics Data System (ADS)
To investigate the influence of spatial distributions of 3D pinning centers on critical current density Jc, BaZrO3-doped YBa2Cu3Oy thin films were fabricated by a quasi-multilayering process. The crossover from a random pinning feature to a peak behavior around the c-axis direction was observed in the angular dependence of Jc when the thickness of a YBCO layer and the growth temperature were modulated. The positions of BaZrO3 particles within the films are considered to be more correlated in the c-axis direction as the thickness of a YBCO layer becomes thinner. The lower growth temperature, on the other hand, suppresses the migration of adatoms, leading to randomly distributed BaZrO3 particles.
Sueyoshi, T.; Mori, M.; Tsuchiya, K.; Yonekura, K.; Fujiyoshi, T.; Mitsugi, F.; Ikegami, T.
Dependence of critical current properties on growth temperature and doping level of nanorods in PLD-YBa2Cu3Oy films
The vortex-Bose-glass-like irreversibility lines (ILs) emerged for 2.5 and 5.0 at.% Ba-Nb-O (BNO)-doped YBa2Cu3Oy films deposited by PLD using Nd:YAG-laser. The ILs strongly depended on growth temperature (Ts) in addition to the doping level of BNO. The vortex glass region was expanded with increasing Ts or doping level of BNO. Drastic change of the nanorod morphology from short and bended nanorods to long and linear nanorods with increasing Ts was clarified. Moreover, it was found that Ts-dependent ILs were quite different from our previous results in BNO-doped ErBa2Cu3Oy films.
Fujita, N.; Haruta, M.; Ichinose, A.; Maeda, T.; Horii, S.
Detection of a coherent boson current in the normal state of a high-temperature superconductor YBa2Cu3Oy film patterned to micrometer-sized rings
The key to clarifying the mechanism of the appearance of high Tc in the high-temperature superconductor seems to be related to the anomalous properties in its normal state [H. Yasuoka, S. Kambe, Y. Itoh, and T. Machi, Physica B 199-200, 278 (1994); H. Ding T. Yokoya, J. C. Campuzano, T. Takahashi, M. Randeria, M. R. Norman, T. Mochiki, K. Kadowaki, and J. Giapintzakis, Nature (London) 382, 51 (1996); and T. Ito, K. Takenaka, and S. Uchida, Phys. Rev. Lett. 70, 3995 (1993)]. Related to this is the presence of Bose-electron-type species such as paired holes [V. J. Emery and S. A. Kivelson, Nature (London) 374, 434 (1995)] and holons [P. W. Anderson, G. Bakaran, Z. Zou, and T. Hsu, Phys. Rev. Lett. 58, 2790 (1987)] in the normal state which has been proposed by theoreticians. We have succeeded in detecting the coherent Bose species in the normal state of YBa2Cu3Oy. The idea [L. P. Levy, G. Dolan, J. Dunsmuir, and H. Bouchiat, Phys. Rev. Lett. 64, 2074 (1990)] of having the detected oscillation of a fermion persisting current caused by the Aharanov-Bohm effect on magnetic field scanning in the assemblage of the mesoscopic rings of metal was employed in the assemblage of a ring patterned in the YB2Cu3Oy film. The sensitivity of our detection system is not high enough to detect fermions, but it is high enough for detecting coherent bosons if they exist. Oscillations with flux periods corresponding to h/2e have been found at T>Tc, even at temperatures 30 K or more above Tc inserted in the patterned YBa2Cu3Oy film, but have not been found in the patterned Au or Pd films. To explain the coherent current circulating in a ring with a circumference as long as 40 ?m, presumably in the prestage to the superconducting stage, the possible coexistence of a minority of coherent bosons and a majority of incoherent bosons is discussed. The detection of minority coherent bosons in the background of a majority of incoherent species is possible in this method.
Kawabata, K.; Tsukui, S.; Shono, Y.; Michikami, O.; Sasakura, H.; Yoshiara, K.; Kakehi, Y.; Yotsuya, T.
Effect of microstructures on critical current density of textured YBa2Cu3Oy
Microsoft Academic Search
Textured YBa2Cu3Oy(YBCO) bulk samples with Jc of magnitude of 105 A\\/cm2 were prepared by different melt procession (MP). Microstructure was examined by means of XRD, SEM and TEM. Very fine particles were observed by TEM. Transport critical current density, hysteresis and magnetization relaxation measurements for the samples show that the Jc and its field dependence vary significantly for the samples
S. Y. Ding; J. W. Lin; J. G. Zheng; Q. Li; Z. Yu; H. L. Mou; L. Zhou; X. X. Yao
Nernst effect in the cuprate superconductor YBa2Cu3Oy: Broken rotational and translational symmetries
The Nernst coefficient of the cuprate superconductor YBa2Cu3Oy was recently shown to become strongly anisotropic within the basal plane when cooled below the pseudogap temperature T?, revealing that the pseudogap phase breaks the fourfold rotational symmetry of the CuO2 planes. Here we report on the evolution of this Nernst anisotropy at low temperature, once superconductivity is suppressed by a magnetic field. We find that the anisotropy drops rapidly below 80 K, to vanish in the T=0 limit. We show that this loss of anisotropy is due to the emergence of a small high-mobility electronlike pocket in the Fermi surface at low temperature, a reconstruction attributed to a low-temperature state that breaks the translational symmetry of the CuO2 planes. We discuss the sequence of broken symmetries�first rotational, then translational�in terms of an electronic nematic-to-smectic transition such as could arise when unidirectional spin or charge modulations order. We compare YBa2Cu3Oy with iron-pnictide superconductors where the process of (unidirectional) antiferromagnetic ordering gives rises to the same sequence of broken symmetries.
Chang, J.; Doiron-Leyraud, Nicolas; Lalibert�, Francis; Daou, R.; Leboeuf, David; Ramshaw, B. J.; Liang, Ruixing; Bonn, D. A.; Hardy, W. N.; Proust, Cyril; Sheikin, I.; Behnia, K.; Taillefer, Louis
Phase transition in the vortex liquid and the critical endpoint in YBa2Cu3Oy
The vortex phase diagram of optimally doped untwinned YBa2Cu3Oy is studied. We find a first-order transition TL(H) in the vortex liquid above the terminal point Hmcp (?7 T) of both the vortex glass line Tg(H) and the field-driven disordering transition line H*(T). The obtained small entropy change (�0.02 kB/vortex/layer) and the critical endpoint Hcep (?11 T) of the TL(H) line indicate that the vortex liquid undergoes the vortex slush regime before the solidification into the vortex glass phase. Below Hmcp, the vortex liquid phase shows the first-order melting transition into the Bragg glass phase. We also study the oxygen content y dependence of the vortex phase diagram and find that the vortex slush regime is located in the borderline (i.e., 6.90?y?6.92) below which the vortex lattice melting transition disappears. The result indicates that the point disorder with the intermediate strength plays an important role in the vortex slush regime.
Shibata, Kenji; Nishizaki, Terukazu; Sasaki, Takahiko; Kobayashi, Norio
Thermo-Electric Study of Fermi Surface Reconstruction in YBa2Cu3Oy
The Seebeck and Nernst coefficients S and ? of the high-Tc superconductor YBa2Cu3Oy (YBCO) were measured in a single crystal with a hole concentration p = 0.12 in magnetic fields up to H = 28 T. For temperatures down to 9 K, ? becomes independent of field by H �30 T, showing that by then the Nernst signal due to superconducting fluctuations has become negligible. In this field-induced normal state, S/T and ?/T are both large and negative in the T ->0 limit. The magnitude of S/T is consistent with the small Fermi surface pocket previously detected via quantum oscillations in YBCO at a similar doping and its negative sign confirms that the pocket is electron-like. The normal-state S(T) of YBCO is remarkably similar to that of La2-xBaxCuO4, La2-x-yNdySrxCuO4 and La2-x-yEuySrxCuO4 at p �1/8, all four materials showing a change of sign at T �50 K. Given that in the latter three materials this change of sign is clearly due to the onset of spin/charge density wave (`stripe') order, we infer that a similar density-wave mechanism must cause the Fermi surface reconstruction in YBCO.
Doiron-Leyraud, N.; Chang, J.; Daou, R.; Leboeuf, D.; Laliberte, F.; Pingault, B.; Taillefer, L.; Proust, C.; Ramshaw, B. J.; Liang, R.; Bonn, D. A.; Hardy, W. N.; Takagi, H.; Antunes, A.; Sheikin, I.; Behnia, K.
Electronic state of vortices in YBa2Cu3Oy investigated by complex surface impedance measurements
The electromagnetic response to microwaves in the mixed state of YBa2Cu3Oy (YBCO) was measured in order to investigate the electronic state inside and outside the vortex core. The magnetic-field dependence of the complex surface impedance at low temperatures was in good agreement with a general vortex dynamics description assuming that the field-independent viscous damping force and the linear restoring force were acting on the vortices. In other words, both real and imaginary parts of the complex resistivity, ?1, and ?2, were linear in B. This is explained by theories for d-wave superconductors. Using analysis based on the Coffey-Clem description of the complex penetration depth, we estimated that the vortex viscosity ? at 10 K was (4-5)�10-7 Ns/m2. This value corresponds to ?0?~0.3-0.5, where ?0 and ? are the minimal gap frequency and the quasiparticle lifetime in the vortex core, respectively. These results suggest that the vortex core in YBCO is not in the deeply superclean regime but in the moderately clean regime. Investigation of the moderately clean vortex core in high-temperature superconductors is significant because physically new effects may be expected due to d-wave characteristics and to the quantum nature of cuprate superconductors. The behavior of Zs as a function of B across the first order transition (FOT) of the vortex lattice was also investigated. Unlike Bi2Sr2CaCu2Oy (BSCCO), no distinct anomaly was observed around the FOT in YBCO. Our results suggest that the rapid increase of Xs due to the change of superfluid density at the FOT would be observed only in highly anisotropic two-dimensional vortex systems like BSCCO. We discuss these results in terms of the difference of the interlayer coupling and the energy scale between the two materials.
Tsuchiya, Yoshishige; Iwaya, Katsuya; Kinoshita, Kentarou; Hanaguri, Tetsuo; Kitano, Haruhisa; Maeda, Atsutaka; Shibata, Kenji; Nishizaki, Terukazu; Kobayashi, Norio
Photo and Electron-Beam-Induced Currents from Epitaxial YBa2Cu3Oy Metal-Insulator-Superconductor (MIS) Structure in the Normal State
We present the first report of observation of photoinduced and electron-beam-induced short-circuit currents across the Al\\/(100)SrTiO3\\/(001)YBa2Cu3Oy metal-insulator-superconductor (MIS) structure in the normal state. Observed current flow is an indication of downward band bending of the YBa2Cu3Oy surface layer at the MIS interface, in accordance with the prediction by Hirano et al. based on its large work-function value (Jpn. J. Appl.
Mamoru Iwabuchi; Takeshi Kobayashi
Dimensional Crossover in the Vortex System of Untwinned YBa2Cu3Oy Single Crystals with Highly Oxygen Deficiency
We have investigated the vortex phase diagram of high-quality untwinned YBa2Cu3Oy (YBCO) single crystals in the underdoped regime. The in-plane resistivity near the transition temperature Tg follows a power law ? ~ (T - Tg)s, indicating a second-order vortex glass to liquid transition. The temperature dependence of the glass transition field is found to follow Hg(T) ~ (1-T/Tc)n with n ~ 4/3 below a certain field H* and change to Hg(T) ~ exp(-aT/Tc) above H*. Moreover, the critical exponent s also changes from 6-7 below H* to a smaller value ~3.6 above H*. These changes in the temperature dependence of the resistivity are attributed to the dimensional crossover in the vortex system.
Fujita, Hiromi; Nishizaki, Terukazu; Kasuga, Kuniaki; Kobayashi, Norio
Lifshitz critical point in the cuprate superconductor YBa2Cu3Oy from high-field Hall effect measurements
The Hall coefficient RH of the cuprate superconductor YBa2Cu3Oy was measured in magnetic fields up to 60 T for a hole concentration p from 0.078 to 0.152 in the underdoped regime. In fields large enough to suppress superconductivity, RH(T) is seen to go from positive at high temperature to negative at low temperature, for p>0.08. This change of sign is attributed to the emergence of an electron pocket in the Fermi surface at low temperature. At p<0.08, the normal-state RH(T) remains positive at all temperatures, increasing monotonically as T?0. We attribute the change of behavior across p=0.08 to a Lifshitz transition, namely a change in Fermi-surface topology occurring at a critical concentration pL=0.08, where the electron pocket vanishes. The loss of the high-mobility electron pocket across pL coincides with a tenfold drop in the conductivity at low temperature, revealed in measurements of the electrical resistivity ? at high fields, showing that the so-called metal-insulator crossover of cuprates is in fact driven by a Lifshitz transition. It also coincides with a jump in the in-plane anisotropy of ?, showing that without its electron pocket, the Fermi surface must have strong twofold in-plane anisotropy. These findings are consistent with a Fermi-surface reconstruction caused by a unidirectional spin-density wave or stripe order.
Leboeuf, David; Doiron-Leyraud, Nicolas; Vignolle, B.; Sutherland, Mike; Ramshaw, B. J.; Levallois, J.; Daou, R.; Lalibert�, Francis; Cyr-Choini�re, Olivier; Chang, Johan; Jo, Y. J.; Balicas, L.; Liang, Ruixing; Bonn, D. A.; Hardy, W. N.; Proust, Cyril; Taillefer, Louis
Inhomogeneous Magnetic-Field Response of YBa2Cu3Oy and La2-xSrxCuO4 Persisting above the Bulk Superconducting Transition Temperature
We report that in YBa2Cu3Oy and La2-xSrxCuO4 there is a spatially inhomogeneous response to the magnetic field for temperatures T extending well above the bulk-superconducting transition temperature Tc. An inhomogeneous magnetic response is observed above Tc even in ortho-II YBa2Cu3O6.50, which has highly ordered doping. The degree of the field inhomogeneity above Tc tracks the hole-doping dependences of both Tc
J. E. Sonier; M. Ilton; V. Pacradouni; C. V. Kaiser; S. A. Sabok-Sayr; Y. Ando; S. Komiya; W. N. Hardy; D. A. Bonn; R. Liang; W. A. Atkinson
Fluorine-doped SnO2 films for solar cell application
Highly conductive transparent thin films of fluorine-doped SnO2 (SnO2:F) were prepared using spray pyrolysis. These films have a potential application in SIS-type photovoltaic solar cells because of their high transmission and low sheet resistance. The electrical resistivity is minimum (about 0.00054 ohms cm) and the figure of merit is maximum (about 0.01) for SnO2 films doped with 1.2 wt.% F.
A. Bhardwaj; B. K. Gupta; A. Raza; A. K. Sharma; O. P. Agnihotri
Weak localization and electron�electron scattering in fluorine-doped SnO2 random nanobelt thin films
Electronic properties of self-assembled high crystalline quality fluorine-doped tin oxide (FTO) nanobelts were studied. We report the experimental transport data of a thin film made using a dispersion of these single-crystal nanobelts. We have shown that the theory of weak localization in a weak disorder regime provides a reasonable description of the observed electrons� transport characteristics of fluorine doped tin oxide nanobelts thin films. Also, our results suggest that the macroscopic extrinsic disorder, related to the random distribution of nanobelts, does not give a noticeable contribution to the whole transport mechanism.
Amorim, Cleber A.; Dalmaschio, Cleocir J.; Melzi, Andr� L. R.; Leite, Edson R.; Chiquito, Adenilson J.
Effects of process parameters on sheet resistance uniformity of fluorine-doped tin oxide thin films.
An alternative indium-free material for transparent conducting oxides of fluorine-doped tin oxide [FTO] thin films deposited on polyethylene terephthalate [PET] was prepared by electron cyclotron resonance - metal organic chemical vapor deposition [ECR-MOCVD]. One of the essential issues regarding metal oxide film deposition is the sheet resistance uniformity of the film. Variations in process parameters, in this case, working and bubbler pressures of ECR-MOCVD, can lead to a change in resistance uniformity. Both the optical transmittance and electrical resistance uniformity of FTO film-coated PET were investigated. The result shows that sheet resistance uniformity and the transmittance of the film are affected significantly by the changes in bubbler pressure but are less influenced by the working pressure of the ECR-MOCVD system. PMID:22221518
Hudaya, Chairul; Park, Ji Hun; Lee, Joong Kee
Effect of quantity of spraying solution on the properties of spray deposited fluorine doped tin oxide thin films
Thin films of fluorine doped tin oxide (F:SnO2) have been prepared using cost effective spray pyrolysis technique. Thin films of different thickness are obtained by varying quantity of spraying solution. Films of up to 1071 nm thickness have been deposited at a maximum growth rate of 3 nm\\/s. The structural, optical and electrical properties of these films have been studied.
A. A. Yadav; E. U. Masumdar; A. V. Moholkar; K. Y. Rajpure; C. H. Bhosale
Thin films of fluorine doped tin oxide (F:SnO2) have been prepared using cost effective spray pyrolysis technique. Thin films of different thickness are obtained by varying quantity of spraying solution. Films of up to 1071nm thickness have been deposited at a maximum growth rate of 3nm\\/s. The structural, optical and electrical properties of these films have been studied. It is
Titanium dioxide-coated fluorine-doped tin oxide thin films for improving overall photoelectric property
Titanium (Ti) layers were deposited by direct current (DC) magnetron sputtering on commercial fluorine-doped tin oxide (FTO) glasses, followed by simultaneous oxidation and annealing treatment in a tubular furnace to prepare titanium dioxide (TiO2)/FTO bilayer films. Large and densely arranged grains were observed on all TiO2/FTO bilayer films. The presence of TiO2 tetragonal rutile phase in the TiO2/FTO bilayer films was confirmed by X-ray diffraction (XRD) analysis. The results of parameter optimization indicated that the TiO2/FTO bilayer film, which was formed by adopting a temperature of 400 �C and an oxygen flow rate of 15 sccm, had the optimal overall photoelectric property with a figure of merit of 2.30 � 10-2 ?-1, higher than 1.78 � 10-2 ?-1 for the FTO single-layer film. After coating a 500 nm-thick AZO layer by DC magnetron sputtering on this TiO2/FTO bilayer film, the figure of merit of the trilayer film achieved to a higher figure of merit of 3.12 � 10-2 ?-1, indicating further improvement of the overall photoelectric property. This work may provide a scientific basis and reference for improving overall photoelectric property of transparent conducting oxide (TCO) films.
Li, Bao-jia; Huang, Li-jing; Ren, Nai-fei; Zhou, Ming
Electron scattering mechanisms in fluorine-doped SnO2 thin films
Polycrystalline fluorine-doped SnO2 (FTO) thin films have been grown by ultrasonic spray pyrolysis on glass substrate. By varying growth conditions, several FTO specimens have been deposited and the study of their structural, electrical, and optical properties has been carried out. By systematically investigating the mobility as a function of carrier density, grain size, and crystallite size, the contribution of each physical mechanism involved in the electron scattering has been derived. A thorough comparison of experimental data and calculations allows to disentangle these different mechanisms and to deduce their relative importance. In particular, the roles of extended structural defects such as grain or twin boundaries as revealed by electron microscopy or x-ray diffraction along with ionized impurities are discussed. As a consequence, based on the quantitative analysis presented here, an experimental methodology leading to the improvement of the electro-optical properties of FTO thin films is reported. FTO thin films assuming an electrical resistivity as low as 3.7 � 10-4 ? cm (square sheet resistance of 8 ?/?) while retaining good transmittance up to 86% (including substrate effect) in the visible range have been obtained.
Rey, G.; Ternon, C.; Modreanu, M.; Mescot, X.; Consonni, V.; Bellet, D.
Electrical and optical properties of fluorine-doped tin oxide (SnOx:F) thin films deposited on PET by using ECR�MOCVD
The electrical, optical, structural and chemical bonding properties of fluorine-doped tin oxide (SnOx:F) films deposited on a plastic substrate prepared by Electron Cyclotron Resonance�Metal Organic Chemical Vapor Deposition\\u000a (ECR�MOCVD) were investigated with special attention to the process parameters such as the H2\\/TMT mole ratio, deposition time and amount of fluorine-doping. The four point probe method, UV visible spectroscopy, scanning\\u000a electron
Ji Hun Park; Dong Jin Byun; Joong Kee Lee
Synthesis of Zinc Oxide Thin Film with Thread-Like Nanowires on Fluorine Doped Tin Oxide Glass Substrates
In this paper, ZnO thin film has been synthesized on fluorine doped tin oxide (FTO) glass substrate by annealing the Zn film in air flow. The SEM image shows that the high density and thread-like ZnO nanowires could grow on the thin film. XRD pattern shows that ZnO was the only compound. The high-resolution transmission electron microscopy (HRTEM) results of individual ZnO nanowires show that the nanowires grown on the ZnO thin film are single-crystalline, and the selected area electron diffraction pattern (SAED) shows that the nanowires grow along the (001) direction.
Li, Xuyang; Kishi, Naoki; Soga, Tetsuo
Sulfur hexafluoride (SF6) as fluorine dopant precursor for production of fluorine doped tin oxide films by MOCVD
SF6 was investigated as an alternative F source for preparing fluorine doped tin oxide films (SnO2:F). SnO2:F films were prepared on glass by low pressure MOCVD using tetramethyltin (Sn(CH3)4) and O2 with SF6 between 500�C and 650�C and 10-65 mol% SF6. These were compared to un-doped SnO2 and SnO2:F grown with CBrF3. SF6 required higher thermal activation than CBrF3. High
Carrie Wyse; Robert Torres; Teresa Barnes; Marty Scott; Matt Young; Xiaonan Li; Tim Gessert
Composition and morphological characteristics of chemically sprayed fluorine-doped zinc oxide thin films deposited on Si(1 0 0)
Fluorine-doped zinc oxide thin films (ZnO:F) were deposited on Si(1 0 0) substrates by the chemical spray technique (CST) from an aged-solution. The effect of the substrate temperature on the morphology and composition of the ZnO:F thin films was studied. The films were polycrystalline, with a preferential growth along the ZnO (0 0 2) plane, irrespective of the deposition temperature. The average crystal size within the films was ca. 35 nm and the morphology of the surface was found to be dependent on the substrate temperature. At low substrate temperatures irregular-shaped grains were observed, whereas at higher temperatures uniform flat grains were obtained. Elemental analysis showed that the composition of the films is close to stoichiometric ZnO and that samples contain quite a low fluorine concentration, which decreases as a function of the deposition temperature.
Casta�eda, L.; Maldonado, A.; Cheang-Wong, J. C.; Terrones, M.; de la L. Olvera, M.
Studies on micro-structural and electrical properties of spray-deposited fluorine-doped tin oxide thin films from low-cost precursor
Thin films of fluorine-doped tin oxide (SnO2:F) on glass were prepared by spray pyrolysis technique using stannous chloride (SnCl2) and ammonium fluoride (NH4F) as precursors. The as-prepared films were characterized for their structural and electrical properties and are discussed in detail in this article. The surface morphology studies revealed that the films are grainy and the roughness of undoped films
E. Elangovan; K. Ramamurthi
Effect of Fluorine Doping on Semiconductor to Metal-Like Transition and Optical Properties of Cadmium Oxide Thin Films Deposited by Sol�Gel Process
Highly conducting fluorine doped n-type cadmium oxide thin films have been synthesized by sol�gel dip coating process on glass and Si substrates for various fluorine concentrations in the films. X-ray diffraction pattern confirmed the cubic CdO phase formation and SEM micrograph showed fine particles of CdO with size ~0.3 �m. F concentration in the films was varied from 1.8% to
P. K. Ghosh; S. Das; S. Kundoo; K. K. Chattopadhyay
Evolution des quasiparticules nodales du cuprate supraconducteur YBa2Cu3Oy en conductivite thermique
Ce memoire presente des mesures de conductivite thermique sur les supraconducteurs YBCO et Tl-2201 afin de statuer sur la presence possible d'un point critique quantique (QCP) dans le diagramme de phase de cuprates. Ce point critique quantique serait a l'origine de la reconstruction de la surface de Fermi, d'un large cylindre de trous en de petites poches de trous et d'electrons. La conductivite thermique dans le regime T ? 0 permet d'extraire une quantite purement electronique liee aux vitesses de Fermi et du gap, au noeud. Une discontinuite dans cette quantite pourrait signaler la traversee du dopage critique qui reconstruit la surface de Fermi. Plusieurs sondes experimentales distinguent une transition de phase ou un crossover a T* a temperature finie. D'autres sondes mettent en evidence une transition de phase sous l'effet d'un champ magnetique. La presence ou non de cet ordre, a temperature et champ magnetique nul questionne la communaute depuis plusieurs annees. Dans cette etude, nous detectons une variation brusque de kappa0/T a p = 0.18 dans YBCO et a p = 0.20 dans Tl-2201. Ces sauts sont interpretes comme un signe de la transition a temperature nulle et sont en faveur d'un QCP. Le manque de donnees d'un meme materiau a ces dopages ne permet pas de valider hors de tout doute l'existence d'un point critique quantique. Le modele theorique YRZ decrit aussi bien les donnees de conductivite thermique. Des pistes de travaux experimentaux a poursuivre sont proposees pour determiner la presence ou non du QCP de facon franche. Mots-cles : Supraconducteurs, cuprates, conductivite thermique, point critique quantique.
Rene de Cotret, Samuel
Effects of TFA addition on the growth of sintered YBa2Cu3Oy superconductors
The effects of trifluoroacetic acid (TFA) addition on the growth of a superconducting phase in sintered YBCO samples were investigated. YBCO samples with TFA addition were prepared by adding TFA (99.0%) to YBCO powder and then pressed into pellets and heated 1173 K - 1213 K for 12 - 20 hr in air. After the heat treatment, the TFA-added sample showed large grain sizes and highly c-axis oriented structures compared to pure YBCO samples, which indicates the enhancement of the grain growth of YBCO sintered samples by the TFA addition. The Jc (0) value and Jc/Jc (0T) properties of the sintered samples was improved by the TFA addition.
Kita, Ryusuke; Kuroda, Keita; Kato, Teppei; Miura, O.; Yamada, K.; Kaneko, K.
Effect of fluorine doping on the structural, optical and electrical properties of SnO2 thin films prepared by spray ultrasonic
The undoped and fluorine doped tin oxide (SnO2) thin films are synthesized by using cost-effective spray ultrasonic technique; the films are sprayed on heated glass substrates at 480 �C. The dependence of structural, optical and electrical properties of SnO2 films on the concentration of fluorine is investigated. X-ray diffraction, Optical absorption, four-point probe and Hall Effect studies have been performed on undoped and fluorine doped SnO2 (FTO) films. X-ray diffraction pattern reveals the presence of cassiterite structure with (2 0 0) as preferential orientation for FTO films. The crystallite size varies from 10.3 to 27.12 nm and was affected by F concentration which was lying between 0 and 12 wt.%. All films exhibit optical transmission T(?) more than 83.9% in visible region; the optically estimated film thickness varies from 700 to 975 nm for the same given time (3 min deposition) and band gap (Eg) varies from 3.651 to 3.902 eV. The electrical study reveals that the films have n-type electrical conductivity and depend upon fluorine concentration too. The sprayed FTO film doped at 6 wt.% has the minimum resistivity of 1.47 � 10-3 ? cm and minimum resistance sheet (Rsh) of 21 ?/cm2 whereas the carrier concentration and mobility were about 2.04 � 1019 cm-3 and 208.4 cm2 V-1 s-1 respectively.
Benhaoua, Atmane; Rahal, Achour; Benhaoua, Boubaker; Jalaci, Mohamed
Fluorine-doped tin dioxide thin films prepared by radio-frequency magnetron sputtering
Tin dioxide thin films doped with fluorine were prepared by using a radio-frequency (RF) magnetron sputtering method. The target was SnO� powder mixed with either SnF� or SnF� powder. The deposition conditions for obtaining films of low resistivity and their physical characteristics were systematically studied. The crystallinity, which was inferior to that of the CVD prepared film, was not improved
Toshiro Maruyama; Hisao Akagi
Influence of RF power and fluorine doping on the properties of sputtered ITO thin films
Highly transparent and conducting ITO thin films were deposited at room temperature by RF magnetron sputtering of ITO target (95wt% In2O3 and 5wt% SnO2) in pure argon atmosphere. Films were deposited at target to substrate spacing of 2cm and 4cm. The influences of RF power on the structural, electrical and optical properties of the films were investigated. The influence of
M. Nisha; M. K. Jayaraj
Fluorine doped tin oxide (FTO) thin film as transparent conductive oxide (TCO) for photovoltaic applications
Textured FTO thin films were deposited on corning glass substrates at 420�C by ultrasonic spray pyrolysis method. The electrical, optical and structural properties of the prepared functional FTO thin films were investigated. Homogeneous textured columnar grain morphology was observed through FESEM. As prepared thin films exhibits polycrystalline cassiterite structure with preferred orientation along (200). FTO is a promising TCO as front electrodes of thin film solar cells because of their good electrical properties (4.3�10-4?.cm) combined with high transmission properties (86%).
Muthukumar, Anusha; Rey, Germain; Giusti, Gael; Consonni, Vincent; Appert, Estelle; Roussel, Herv�; Dakshnamoorthy, Arivuoli; Bellet, Daniel
Electrical, structural and surface properties of fluorine doped tin oxide films
Fluorine (F) incorporated polycrystalline SnO 2 films have been deposited onto glass substrates by ultrasonic spray pyrolysis technique. To possess information about the electrical properties of all films, their electrical conductivities were investigated depending on the temperature, and their activation and trap energies were analyzed. The crystalline structure, surface properties and elemental analysis of the SnO 2 films were examined to determine the effect of the F element. After all investigations, it was concluded that each fluorine incorporation rate has a different and important effect on the physical properties, and SnO 2:F (3 at%) films were found to be the most promising sample for energy conversion devices, especially as conducting electrode in solar cells with its improved structural and electrical properties as compared to others.
Bilgin, V.; Akyuz, I.; Ketenci, E.; Kose, S.; Atay, F.
High-T sub c fluorine-doped YBa2Cu3O(y) films on ceramic substrates by screen printing
NASA Technical Reports Server (NTRS)
Thick films of fluorine-doped YBa2Cu3O(y) were screen printed on highly polished alumina, magnesia spinel, strontium titanate, and yttria-stabilized zirconia (YSZ) substrates. They were annealed at 1000 C and soaked in oxygen at 450 C, followed by slow cooling to room temperature. The films were characterized by electrical resistivity measurements as a function of temperature and x-ray diffraction. The film on YSZ showed the best characteristics with a T sub c (onset) of 91 K, T sub c (R equals 0) of 88.2 K, and a transition width, delta T sub c (10-90 percent), of approximately 1.7 K. The film adhesion, probably controlled by interdiffusion of cations between the film and the substrate, was good in all cases except on strontium titanate where the film completely detached from the substrate.
Bansal, Narottam P.
SciTech Connect
Bansal, N.P.
Spray deposition of highly transparent fluorine doped cadmium oxide thin films
The cadmium oxide (CdO) and F:CdO films have been deposited by spray pyrolysis method using cadmium acetate and ammonium fluoride as precursors for Cd and F ions, respectively. The effect of temperature and F doping on the structural, morphological, optical and Hall effect properties of sprayed CdO thin films was investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), optical absorption and electrical measurement techniques. TGA and DTA studies, indicates the formation of CdO by decomposition of cadmium acetate after 250 �C. XRD patterns reveal that samples are polycrystalline with cubic structure and exhibits (2 0 0) preferential orientation. Considerable broading of (2 0 0) peak, simultaneous shifting of corresponding Bragg's angle have been observed with respect to F doping level. SEM and AFM show the heterogeneous distribution of cubical grains all over the substrate, which are randomly distributed. F doping shifts the optical gap along with the increase in the transparency of CdO films. The Hall effect measurement indicates that the resistivity and mobility decrease up to 4% F doping.
Deokate, R. J.; Pawar, S. M.; Moholkar, A. V.; Sawant, V. S.; Pawar, C. A.; Bhosale, C. H.; Rajpure, K. Y.
Physicochemical characterization of point defects in fluorine doped tin oxide films
The physical and chemical properties of spray deposited FTO films are studied using FESEM, x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), electrical and optical measurements. The results of XRD measurements showed that the films are polycrystalline (grain size 20-50 nm) with Rutile structure and mixed preferred orientation along the (200) and (110) planes. An angular shift of the XRD peaks after F-doping is observed and interpreted as being due to the formation of substitutional fluorine defects (F{sub O}) in presence of high concentration of oxygen vacancies (V{sub O}) that are electrically neutral. The electrical neutrality of oxygen vacancies is supported by the observation that the electron concentration n is two orders of magnitude lower than the V{sub O} concentration calculated from chemical analyses using XPS measurements. It is shown that an agreement between XPS, XRD, and Hall effect results is possible provided that the degree of deviation from stoichiometry is calculated with the assumption that the major part of the bulk carbon content is involved in O-C bonds. High temperature thermal annealing is found to cause an increase in the F{sub O} concentration and a decrease in both n and V{sub O} concentrations with the increase of the annealing temperature. These results could be interpreted in terms of a high temperature chemical exchange reaction between the SnO{sub 2} matrix and a precipitated fluoride phase. In this reaction, fluorine is released to the matrix and Sn is trapped by the fluoride phase, thus creating substitutional fluorine F{sub O} and tin vacancy V{sub Sn} defects. The enthalpy of this reaction is determined to be approximately 2.4 eV while the energy of formation of a V{sub Sn} through the migration of Sn{sub Sn} host atom to the fluoride phase is approximately 0.45 eV.
El Akkad, Fikry; Joseph, Sudeep [Physics Department, Kuwait University, P.O. Box 5969, Safat 13060 (Kuwait)
Variation of applied field angular dependence of critical current density in YBCO thin films against deposition temperature and composition
For the magnetic flux pinning in YBa2Cu3Oy (YBCO) thin films, artificial pinning centers (APC) like BaZrO3 and BaSnO3 nanorods act effectively when magnetic fields are applied parallel to the c-axis of the YBCO thin films. However, it is necessary that APC exist into a three dimentional shape and random distribution in order to enhance Jc against all angle range of applied magnetic fields. In this study, we reported YBCO thin films with low anisotropy of Jc against the magnetic field applied angle. As a result, using off-stoichiometric target composition of Y: Ba: Cu = 1: 2: 3.4 and high substrate temperatures, the YBCO thin films which were prepared by pulsed laser deposition method at more than 890 �C showed low anisotropic Jc, since the films included pinning centers acting against wide angle range of applied field.
Matsunami, T.; Ichino, Y.; Yoshida, Y.; Ichinose, A.; Matsumoto, K.
Solution-Processed Flexible Fluorine-doped Indium Zinc Oxide Thin-Film Transistors Fabricated on Plastic Film at Low Temperature
PubMed Central
Transparent flexible fluorine-doped indium zinc oxide (IZO:F) thin-film transistors (TFTs) were demonstrated using the spin-coating method of the metal fluoride precursor aqueous solution with annealing at 200�C for 2?hrs on polyethylene naphthalate films. The proposed thermal evolution mechanism of metal fluoride aqueous precursor solution examined by thermogravimetric analysis and Raman spectroscopy can easily explain oxide formation. The chemical composition analysed by XPS confirms that the fluorine was doped in the thin films annealed below 250�C. In the IZO:F thin films, a doped fluorine atom substitutes for an oxygen atom generating a free electron or occupies an oxygen vacancy site eliminating an electron trap site. These dual roles of the doped fluorine can enhance the mobility and improve the gate bias stability of the TFTs. Therefore, the transparent flexible IZO:F TFT shows a high mobility of up to 4.1?cm2/V�s and stable characteristics under the various gate bias and temperature stresses.
Seo, Jin-Suk; Jeon, Jun-Hyuck; Hwang, Young Hwan; Park, Hyungjin; Ryu, Minki; Park, Sang-Hee Ko; Bae, Byeong-Soo
Effect of N2 Plasma Annealing on Properties of Fluorine Doped Silicon Dioxide Films with Low Dielectric Constant for Ultra-Large-Scale Integrated Circuits
The influence of N2 plasma annealing on the properties of fluorine doped silicon oxide (SiOF) films is investigated. The stability of the dielectric constant of SiOF film is remarkably improved by the N2 plasma annealing. After enduring a moisture absorption test for six hours in a chamber with 60% humidity at 50�C, the dielectric constant variation of the annealed SiOF films is only 1.5%, while the variation for those SiOF films without annealing is 15.5%. Fourier transform infrared spectroscopic results show that the absorption peaks of Si-OH and H-OH of SiOF films are reduced after the N2 plasma annealing because the annealing can wipe off some unstable Si-F2 bonds in SiOF films. These unstable Si-F2 bonds are suitable to react with water, resulting in the degradation of SiOF film properties. Therefore, the N2 plasma annealing meliorates the properties of SiOF films with low dielectric constant.
Zhang, Wei; Wang, Peng-Fei; Ding, Shi-Jin; Wang, Ji-Tao; William, Wei Lee
Thickness effects on the texture development of fluorine-doped SnO2 thin films: The role of surface and strain energy
Polycrystalline fluorine-doped SnO2 thin films have been grown by ultrasonic spray pyrolysis with a thickness varying in the range of 40 to 600 nm. A texture transition from <110> to <100> and <301> crystallographic orientations has experimentally been shown by x-ray diffraction measurements as film thickness is increased, showing that a process of abnormal grain growth has occurred. The texture effects are considered within a thermodynamic approach, in which the minimization of total free energy constitutes the driving force for grain growth. For very small film thickness, it is found that the <110> preferred orientation is due to surface energy minimization, as the (110) planes have the lowest surface energy in the rutile structure. In contrast, as film thickness is increased, the <100> and <301> crystallographic orientations are progressively predominant, owing to elastic strain energy minimization in which the anisotropic character is considered in the elastic biaxial modulus. A texture map is eventually determined, revealing the expected texture as a function of elastic strain and film thickness.
Consonni, V.; Rey, G.; Roussel, H.; Bellet, D.
Optimal ablation of fluorine-doped tin oxide (FTO) thin film layers adopting a simple pulsed Nd:YAG laser with TEM 00 mode
In material processing, a laser system with optimal laser parameters has been considered to be significant. Especially, the laser ablation technology is thought to be very important for fabricating a dye-sensitized solar cell (DSSC) module with good quality. Moreover, the TEM 00 mode laser beam is the most dominant factor to decide the incident photon to current conversion efficiency (IPCE) characteristics. In order to get the TEM 00 mode, a pin-hole is inserted within a simple pulsed Nd:YAG laser resonator. And the spatial field distribution is measured by using three pin-hole diameters of 1.6, 2.0 and 4.0 mm, respectively. At that moment, each case has the same laser beam energy by adjusting the discharge voltage and pulse per second (pps). From those results, it is known that the pin-hole size of 1.6 mm has the perfect TEM 00 mode. In addition, at the charging voltage of 1000 V, 10 pps, the feeding speed of 6.08 mm/s and the overlapping rate (OL) of 62%, the scanning electron microscope (SEM) photograph of fluorine-doped tin oxide (FTO) thin film layers shows the best ablation trace.
Kim, Hee-Je; Lee, Myung-Sik; Lee, Dong-Gil; Son, Min-Kyu; Lee, Kyoung-Jun
Novel nanostructure zinc zirconate, zinc oxide or zirconium oxide pastes coated on fluorine doped tin oxide thin film as photoelectrochemical working electrodes for dye-sensitized solar cell
Zinc zirconate (ZnZrO3) (ZZ), zinc oxide (ZnO) (ZO) and zirconium oxide (ZrO2) (ZRO) nano-particles were synthesized by simple sol-gel method. ZZ, ZO and ZRO nano-particles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and UV-Vis diffuse reflectance spectrum (DRS). Nanoporous ZZ, ZO and ZRO thin films were prepared doctor blade technique on the fluorine-doped tin oxide (FTO) and used as working electrodes in dye sensitized solar cells (DSSC). Their photovoltaic behavior were compared with standard using D35 dye and an electrolyte containing [Co(bpy)3](PF6)2, [Co(pby)3](PF6)3, LiClO4, and 4-tert-butylpyridine (TBP). The properties of DSSC have been studied by measuring their short-circuit photocurrent density (Jsc), open-circuit voltage (VOC) and fill factor (ff). The application of ZnZrO3 as working electrode produces a significant improvement in the fill factor (ff) of the dye-sensitized solar cells (ff = 56%) compared to ZnO working electrode (ff = 40%) under the same condition.
Hossein Habibi, Mohammad; Askari, Elham; Habibi, Mehdi; Zendehdel, Mahmoud
Low Dielectric Constant Interlayer Using Fluorine-Doped Silicon Oxide
A new interlayer dielectric film using fluorine-doped silicon oxide (SiOF) for multilevel interconnection of very large scale integration (VLSI) has been fabricated. The film is deposited by a simple technique, which is hexafluoroethane ( C2F6) addition to conventional tetraethoxysilane (TEOS)-based plasma-enhanced chemical vapor deposition (PE-CVD). Si F bond formation in the film is detected by chemical bonding structural studies using
Takashi Usami; Kimiaki Shimokawa; Masaki Yoshimaru
Structural, optical, electrical properties and FTIR studies of fluorine doped SnO 2 films deposited by spray pyrolysis
Thin films of SnO2:F were prepared by ultrasonic spray pyrolysis method. The effect of fluorine concentration on the structural, optical, and\\u000a electrical properties of SnO2:F films was investigated. The X-ray diffraction results showed the preferred growth along (110). FTIR was employed to study\\u000a the defects in SnO2 lattice. The evidence of oxygen vacancy and substitution of fluorine for oxygen in
B. Zhang; Y. Tian; J. X. Zhang; W. Cai
Microwave surface resistance of YBCO superconducting thin films under high DC magnetic field
We investigated the dc magnetic field and temperature dependences of the microwave surface resistance (Rs) of YBa2Cu3Oy (YBCO) superconducting thin films with various thicknesses. We used YBCO thin films with 300, 500, and 700 nm deposited on a MgO (1 0 0) substrate by the thermal co-evaporation method. The Rs was measured using the dielectric resonator method at 21.8 GHz, and a high dc magnetic field of up to 12 T was applied parallel to the c-axis of the YBCO thin films during Rs measurements. The Rs value of YBCO thin films increased when dc magnetic field was applied. These relationships could be explained by using the two-fluid model for high frequency and low magnetic field limits. We defined the viscous drag coefficient ? under the low magnetic limit and the high magnetic field limit as the ?low (B, T, d) and ?high (B, T, d), respectively. The ?low values were approximately two orders of magnitude greater than ?high values. Also, all ?low and ?high value decreased or saturated as the temperature and film thickness increased. These results show that ? under the low and high magnetic field limit depended on the temperature and film thickness.
Honma, T.; Sato, S.; Sato, K.; Watanabe, M.; Saito, A.; Koike, K.; Kato, H.; Ohshima, S.
A study of room-temperature ferromagnetism in transition metal and fluorine-doped spray-pyrolyzed SnO2 thin films
Room-temperature ferromagnetism has been observed in Co- or Mn-doped SnO2 and Co- and F-co-doped SnO2 thin films. A maximum magnetic moment of 0.80muB\\/Co ion has been observed for Sn0.90Co0.10O1.925-deltaF0.075 thin films, whereas in the case of Sn1-xMnxO2-delta it was 0.18muB\\/Mn ion for x=0.10. The magnetization of both Sn1-xCoxO2-delta and Sn1-xCoxO2-y-deltaFy thin films depends on the free carrier concentration. An anomalous
Subhash C. Kashyap; K. Gopinadhan; D. K. Pandya; Sujeet Chaudhary
A study of room-temperature ferromagnetism in transition metal and fluorine-doped spray-pyrolyzed SnO 2 thin films
Room-temperature ferromagnetism has been observed in Co- or Mn-doped SnO2 and Co- and F-co-doped SnO2 thin films. A maximum magnetic moment of 0.80?B\\/Co ion has been observed for Sn0.90Co0.10O1.925??F0.075 thin films, whereas in the case of Sn1?xMnxO2?? it was 0.18?B\\/Mn ion for x=0.10. The magnetization of both Sn1?xCoxO2?? and Sn1?xCoxO2?y??Fy thin films depends on the free carrier concentration. An anomalous
Adsorption and desorption properties on the fluorine-doped tin oxide film surface on a glass substrate under UV light irradiation in vacuum
Various functional metal-oxide coatings on glass substrate have the possibility to be used for many applications in these days. For keeping the high performance of these applications, it is very important to understand the adsorption property on those coating surfaces. However, there are few reports about such properties of metal-oxide film surface in vacuum state, especially the carbon adsorption property
Tetsuo Minaai; Atsushi Nara; Mika Kumagai; Sakae Tanemura; Masaki Tanemura
Chemical vapor deposition of fluorine-doped zinc oxide
Fims of fluorine-doped zinc oxide are deposited from vaporized precursor compounds comprising a chelate of a dialkylzinc, such as an amine chelate, an oxygen source, and a fluorine source. The coatings are highly electrically conductive, transparent to visible light, reflective to infrared radiation, absorbing to ultraviolet light, and free of carbon impurity.
Gordon, Roy G. (Cambridge, MA); Kramer, Keith (Avon Lake, OH); Liang, Haifan (Santa Clara, CA)
Optical properties of indium tin oxide and fluorine-doped tin oxide surfaces: correlation of reflectivity, skin depth, and plasmon frequency with conductivity
Variable angle reflectance FTIR was used to investigate the reflectance of thin films of either indium tin oxide (ITO) or fluorine-doped tin oxide (SFO) on glass substrates in the mid-IR. The reflectance was observed to depend on the incident angle, wavenumber, and the polarization used. The Drude model and the Fresnel equations for reflection at a single dielectric boundary were
Scott H. Brewer; Stefan Franzen
Fluorine doped-tin oxide prepared using spray method for dye sensitized solar cell application
Fluorine-doped Tin Oxide (FTO) film was fabricated by spray deposition method. FTO films were prepared in different sheet resistance 6.7, 12.1, 19.3, and 23.5 ?/sq. X-ray diffractograms showed that the as-grown FTO film was tetragonal SnO2. The prepared FTO film have an average transmittance of 80% in the visible region (?=400-800 nm). These FTO films were then used to fabricate Dye Sensitized Solar Cell (DSSC). The working electrode was made from TiO2 paste using doctor blade technique. DSSC samples were characterized using solar simulator under AM 1.5 (100 mW/cm2). It is found that the efficiency of DSSC was much affected by sheet resistance of FTO film. The efficiency of DCCS was 2.32, 2.4, 1.1 and 0.97 (%) for the FTO sheet resistance 6.7, 12.1, 19.3, and 23.5 ?/sq, respectively. It is shown that the optimum DSSC efficiency was made from FTO with sheet resistance 12.1 ?/sq.
Widiyandari, Hendri; Purwanto, Agus; Diharjo, Kuncoro; Suyitno; Hidayanto, Eko
Preparation of fluorine-doped, carbon-encapsulated hollow Fe3O4 spheres as an efficient anode material for Li-ion batteries
Herein we report the design and synthesis of fluorine-doped, carbon-encapsulated hollow Fe3O4 spheres (h-Fe3O4@C/F) through mild heating of polyvinylidene fluoride (PVDF)-coated hollow Fe3O4 spheres. The spheres exhibit enhanced cyclic and rate performances. The as-prepared h-Fe3O4@C/F shows significantly improved electrochemical performance, with high reversible capacities of over 930 mA h g-1 at a rate of 0.1 C after 70 cycles, 800 mA h g-1 at a rate of 0.5 C after 120 cycles and 620 mA h g-1 at a rate of 1 C after 200 cycles. This improved lithium storage performance is mainly ascribed to the encapsulation of the spheres with fluorine-doped carbon, which not only improves the reaction kinetics and stability of the solid electrolyte interface film but also prevents aggregation and drastic volume change of the Fe3O4 particles. These spheres thus represent a promising anode material in lithium-ion battery applications.Herein we report the design and synthesis of fluorine-doped, carbon-encapsulated hollow Fe3O4 spheres (h-Fe3O4@C/F) through mild heating of polyvinylidene fluoride (PVDF)-coated hollow Fe3O4 spheres. The spheres exhibit enhanced cyclic and rate performances. The as-prepared h-Fe3O4@C/F shows significantly improved electrochemical performance, with high reversible capacities of over 930 mA h g-1 at a rate of 0.1 C after 70 cycles, 800 mA h g-1 at a rate of 0.5 C after 120 cycles and 620 mA h g-1 at a rate of 1 C after 200 cycles. This improved lithium storage performance is mainly ascribed to the encapsulation of the spheres with fluorine-doped carbon, which not only improves the reaction kinetics and stability of the solid electrolyte interface film but also prevents aggregation and drastic volume change of the Fe3O4 particles. These spheres thus represent a promising anode material in lithium-ion battery applications. Electronic supplementary information (ESI) available: Additional TGA, SEM, TEM, HRTEM, EDX spectra and elemental mapping, XRD and electrochemical data. See DOI: 10.1039/c3nr06409c
Geng, Hongbo; Zhou, Qun; Pan, Yue; Gu, Hongwei; Zheng, Junwei
Microwave-electrochemical formation of colloidal zinc oxide at fluorine doped tin oxide electrodes
Colloidal ZnO is obtained during microwave-enhanced electrochemical deposition experiments from an aqueous solution containing 0 1 M Zn(NO(3))(2) and 0 02 M H(2)O(2) via repetitive negative going potential cycles from 03 to 0 8 V vs SCE The effects of temperature and temperature gradients on ZnO electro formation at fluorine doped tin oxide (FTO) electrodes are investigated with both a
Liza Rassaei; Robben Jaber; Stephen E. Flower; Karen J. Edler; Richard G. Compton; Tony D. James; Frank Marken
Preparation, characterization and electrical properties of fluorine-doped tin dioxide nanocrystals
Fluorine-doped tin dioxide (FTO) nanocrystals were prepared with a sol�gel process followed by a hydrothermal treatment using SnCl4 and NH4F as SnO2 and fluorine dopant, respectively. The nanostructure and composition were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), zeta potential analysis, electrochemical measurement technology and X-ray photoelectron spectroscopy (XPS) respectively. The diameter of
Shanshan Wu; Shuai Yuan; Liyi Shi; Yin Zhao; Jianhui Fang
Plasma outside deposition (POD) of fluorine doped silica for high-power laser applications
The plasma outside deposition (POD) process is the basic technology for production of large core multimode silica fibers with highly fluorine doped cladding. Due to the all silica fiber construction such fibers can transmit several 10 kW of light power even with a core of 100 ?m or less. An overview of the current capabilities and trends in high power laser applications will be presented, including very large fibers, shaped core and cladding designs and fibers with multiple claddings or multiple cores. These concepts can be applied to transmission fibers as well as fiber lasers. Heraeus is supporting these new developments by offering a growing number of materials, preforms and services.
Langner, Andreas; Sch�tz, Gerhard
Fundamental electrochemiluminescence characteristics of fluorine-doped tin oxides synthesized by sol-gel combustion.
Fluorine-doped tin oxide (FTO) materials synthesized by sol-gel combustion method were investigated for electrochemical luminescence (ECL) application. Effects of sol-gel combustion conditions on the structures and morphology of the porous FTO (p-FTO) materials were studied. ECL efficiency of p-FTO-based cell was about 251 cd/m2 at 4 V bias, which is higher than the sell using only FTO electrodes (102.8 cd/m2). The highest intensity of the emitting light was obtained at the wavelength of about 610 nm. The porous FTO layer was effective for increasing ECL intensities. PMID:24245225
Moon, B H; Chaoumead, A; Sung, Y M
Surface functionalization of fluorine-doped tin oxide samples through electrochemical grafting.
Transparent conductive oxides are emerging materials in several fields, such as photovoltaics, photoelectrochemistry, and optical biosensing. Their high chemical inertia, which ensured long-term stability on one side, makes challenging the surface modification of transparent conductive oxides; long-term robust modification, high yields, and selective surface modifications are essential prerequisite for any further developments. In this work, we aim at inducing chemical functionality on fluorine-doped tin oxide surfaces (one of the most inexpensive transparent conductive oxide) by means of electrochemical grafting of aryl diazonium cations. The grafted layers are fully characterized by photoemission spectroscopy, cyclic voltammetry, and atomic force microscopy showing linear correlation between surface coverage and degree of modification. The electrochemical barrier effect of modified surfaces was studied at different pH to characterize the chemical nature of the coating. We showed immuno recognition of biotin complex built onto grafted fluorine-doped tin oxides, which opens the perspective of integrating FTO samples with biological-based devices. PMID:24171474
Lamberti, F; Agnoli, S; Brigo, L; Granozzi, G; Giomo, M; Elvassore, N
Fluorine doped SnO2 (FTO) nanobelts: some data on electronic parameters
Fluorine doped SnO2 (FTO) nanobelts were synthesized and their transport properties, such as conduction mechanism, mobility, carrier density and density of states (DOS) were investigated. Variable range hopping was observed as the dominant mechanism in a large range of temperature (40-260 K). Through these data we estimated the localization length and hopping distance at 300 K of FTO nanobelts exhibiting a three-dimensional character for carrier transport. The carrier mobility was calculated to be 48 cm2 V-1 s-1 for samples with carrier density of 2 � 1018 cm-3. Taking into account the parameters obtained from temperature-dependent resistivity and the above data, the characteristic DOS at Fermi level in our samples was found.
Amorim, Cleber A.; Dalmaschio, Cleocir J.; Leite, Edson R.; Chiquito, Adenilson J.
Synthesis of Aligned Copper Oxide Nanowires on Fluorine-Doped Tin Oxide Glass Substrate
In this paper, the synthesis and characterization of uniform and dense CuO nanowires on fluorine-doped tin oxide (FTO) glass substrate are reported. The procedure simply involved the vapor-solid thermal oxidation growth process of CuO nanowires on FTO surface in the air flow. The sample was annealed in air within the temperature range 300-600�C for 1 h. The morphology and density of the CuO nanowires could be controlled by annealing temperature. The SEM image analysis indicates that the nanowires feature uniform size with aligned structures. The high-resolution transmission electron microscopy (HRTEM) result of individual CuO nanowires shows that the nanowires were single-crystalline, and the selected area diffraction pattern (SEAD) of the same sample shows that the nanowires grow along the (110) direction. The XRD analysis shows that CuO was the only product when the sample annealed at the temperature higher than 500�C.
Magnesium-doped zinc oxide electrochemically grown on fluorine-doped tin oxide substrate.
Nanostructures of magnesium (Mg) doped Zinc oxide (ZnO) were successfully deposited on conducting fluorine-doped tin oxide (FTO) coated glass plates by cathodic electrochemical deposition method at different potentials and temperature conditions. The deposited samples were characterized by XRD and SEM techniques to confirm their structures, morphologies and optical properties. These measurements show that Mg doped ZnO has a wurtzite structure and that the strongest intensity of the (002) peak is found at 60 degrees C and -1.0 V. Tunable transmittance of Mg doped ZnO has a band gap energy from 3.45 eV to 3.82 eV, which is the direct evidence of doping. PMID:22849195
Han, Q F; Jeong, Y I; Heo, J H; Shin, C M; Ryu, H; Park, M S; Lee, W J; Yoon, J H; Yang, J E; Choi, H
Influence of the manufacturing process on the radiation sensitivity of fluorine-doped silica-based optical fibers
In this work, we analyze the origins of the observed differences between the radiation sensitivities of fluorine-doped optical fibers made with different fabrication processes. We used several experimental techniques, coupling in situ radiation-induced absorption measurements with post mortem confocal microscopy luminescence measurements. Our data showed that the silica intrinsic defects are generated both from precursors and from strained regular Si-O-Si
A. Alessi; S. Girard; C. Marcandella; L. Vaccaro; M. Cannas; A. Boukenter; Y. Ouerdane
Effect of electrodeposition modes on surface characteristics and corrosion properties of fluorine-doped hydroxyapatite coatings on Mg-Zn-Ca alloy
The microstructure, morphology and composition highly determine the corrosion resistance and bioactivity of coating. In traditional cathodic electrodeposition process, because of the unfavorable effects of the polarization of concentration difference and H 2 evolution, fluorine-doped hydroxyapatite coating was loose and porous. This coating could not ensure the long-term stability of the Mg alloy implants. In order to improve the corrosion resistance and bioactivity of coating, pulse electrodeposition and H 2O 2 were introduced into the electrodeposition to deposit fluorine-doped hydroxyapatite coating. As a comparative study, microstructure, corrosion resistance properties and bioactivity of traditional cathodic electrodeposition coating and pulse electrodeposition coating were investigated, respectively. The results revealed that nano fluorine-doped hydroxyapatite coating could be prepared by pulse electrodeposition, and the coating was dense and uniform. The potentiodynamic polarization experiment indicated that the dense and uniform coating could effectively protect Mg alloy substrate from corrosion. Immersion testing was performed in simulated body fluid. It was found that pulse electrodeposition coating could more effectively induce the precipitation of Mg 2+, Ca 2+ and PO 43- in comparison with traditional cathodic electrodeposition coating, because the nano phase had comparatively high specific surface area. Thus magnesium alloy coated with fluorine-doped nano-hydroxyapatite coating may be a promising candidate as biodegradable bone implants, and was worthwhile to further investigate the in vivo degradation behavior.
Meng, E. C.; Guan, S. K.; Wang, H. X.; Wang, L. G.; Zhu, S. J.; Hu, J. H.; Ren, C. X.; Gao, J. H.; Feng, Y. S.
AlGaN-based ultraviolet light-emitting diodes using fluorine-doped indium tin oxide electrodes
In this paper, improved electrical and optical properties of aluminum gallium nitride (AlGaN)-based ultraviolet light-emitting diodes using fluorine-doped indium tin oxide (F-ITO) electrodes are reported. F-doping was found to increase the work function as well as the energy bandgap of the ITO and, thereby, reduce the Shottky barrier height in contact with p-(Al)GaN. As a result, the optical transmittance increased from 79.7% to 86.9% at 380 nm, while the specific contact resistance decreased from 1.04 � 10-3 ?.cm2 to 9.12 � 10-4 ?.cm2 after F-doping, which led to an increase in the output power from 2.41 mW to 5.99 mW.
Ju Chae, Dong; Yoon Kim, Dong; Geun Kim, Tae; Mo Sung, Yun; Doeck Kim, Moon
Dependence of of thickness F-doped SnO2 films grown by spray pyrolysis technique
Transparent conducting thin films of fluorine-doped SnO2 were deposited on glass substrates by spray pyrolysis technique in order to find out the effect of film thickness. These films were prepared using fluorine concentrations of 4 mol% at substrate temperature of 500�C. Their electrical resistivity decreased although optical transmittance decreased with increasing the film thickness.
Minoru Oshima; Yujin Takemoto; Kenji Yoshino
Superconductivity and phase diagram in iron-based arsenic-oxides ReFeAsO1?? (Re = rare-earth metal) without fluorine doping
Here we report a new class of superconductors prepared by high-pressure synthesis in the quaternary family ReFeAsO1?? (Re=Sm, Nd, Pr, Ce, La) without fluorine doping. The onset superconducting critical temperature (Tc) in these compounds increases with the reduction of the Re atom size, and the highest Tc obtained so far is 55 K in SmFeAsO1??. For the NdFeAsO1?? compound with
Zhi-An Ren; Guang-Can Che; Xiao-Li Dong; Jie Yang; Wei Lu; Wei Yi; Xiao-Li Shen; Zheng-Cai Li; Li-Ling Sun; Fang Zhou; Zhong-Xian Zhao
Enhancement in the antibacterial efficiency of ZnO nanopowders by tuning the shape of the nanograins through fluorine doping
Fluorine doped ZnO nanopowders were synthesized from starting solutions having different doping levels of F (0, 5, � , 20 at.%) using a simple soft chemical route and the effects of the doping level on the structural, optical, surface morphological and antibacterial properties were investigated. The XRD studies reveal that all the products have preferential orientation along the (1 0 1) plane. The PL studies show that all the samples exhibit strong visible emission with a peak at 425 nm. The enhancement in the visible emission indicates an increasing number of surface defects caused by the doping of F. The obtained FTIR spectra confirm the incorporation of F into ZnO lattice. From the SEM studies, it is observed that the ZnO nanowires formed at 10 at.% of F doping level exhibit excellent antibacterial activities. Antibacterial activity of F doped ZnO nanopowders against Staphylococcus aureus was found to be significantly higher than that against the Escherichia coli and Pseudomonas aeruginosa micro-organisms. All the physical properties were corroborated well with the findings related to antibacterial activity. Finally, we conclude that, the analysis of all the results shows that F doping level of 10 at.% is optimal in all respects and is suitable for antibacterial applications.
Ravichandran, K.; Snega, S.; Jabena Begum, N.; Swaminathan, K.; Sakthivel, B.; Rene Christena, L.; Chandramohan, G.; Ochiai, Shizuyasu
Electrochromism of the electroless deposited cuprous oxide films
Thin cuprous oxide films were prepared by a low cost, chemical deposition (electroless) method onto glass substrates pre-coated with fluorine doped tin oxide. The X-ray diffraction pattern confirmed the Cu2O composition of the films. Visible transmittance spectra of the cuprous oxide films were studied for the as-prepared, colored and bleached films. The cyclic voltammetry study showed that those films exhibited
R. Neskovska; M. Ristova; J. Velevska; M. Ristov
Electron and Atomic Force Microscopy studies of photocatalytic titanium dioxide thin films deposited by DC magnetron sputtering
Titanium dioxide thin films were deposited on glass substrates and on fluorine doped tin oxides at room temperature by DC magnetron sputtering at different working gas pressures and were evaluated using photocatalytic degradation of an organic compound. The structural properties of the films were studied by electron microscopy techniques and Atomic Force Microscopy. Numerous structural defects were detected for samples
Dwight R. Acosta; Arturo Mart�nez; Carlos R. Maga�a; Jes�s M. Ortega
Microwave shielding of fluorine-doped tin oxide film obtained by spray pyrolysis studied by electrical characterization
In this work, we report dc conductivity and Hall effect results for glasses coated with commercial In2O3:Sn and SnO2:F. Van der Pauw Hall effect and resistivity measurements were used to carry out the sheet resistance of the samples and to determine their carrier density, mobility, and conductivity from 10 to 325 K. We calculated the transmission from the dc measurements
C. P. L Rubinger; A. F. da Cunha; F. Vinagre; G. M. Ribeiro; L. C. Costa
Synthesis and characterization of Cu2ZnSnSe4 nanotube arrays on fluorine-doped tin oxide glass substrates
Highly ordered arrays of Cu2ZnSnSe4 nanotubes have been successfully synthesized on fluorine-doped tin oxide glass substrate using ZnO nanorod arrays as sacrificial templates. The structure, morphology and optical properties of the Cu2ZnSnSe4 arrays were characterized by X-ray diffraction, Raman spectrometry, field-emission scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray, and UV-Vis absorption spectroscopy. The diameter and length of the Cu2ZnSnSe4 nanotubes can be adjusted by tuning the diameter and length of the ZnO nanorods. In addition, the effect of the length on the performance of the photoelectrochemical cells was also investigated.
Zhang, Wei; Yu, Wenxue; Zhang, Lina; Yang, Haibin; Fu, Wuyou; Li, Minghui; Li, Yixing
Spray pyrolytically deposited PbS thin films
The spray pyrolysis technique has been employed to prepare uniform, large-area thin-film coatings of PbS on glass and on fluorine-doped tin oxide (FTO) conducting substrates at various substrate temperatures. Growth of polycrystalline PbS films occurred at a lower temperature (TS = 275 �C) on conducting substrate than on glass (TS = 325 �C) and oriented growth of polycrystalline cubic PbS
B. Thangaraju; P. Kaliannan
Substrate dependent properties of electrodeposited EuTe thin films
In electrodeposition, substrate besides providing mechanical support to the electrodeposit, affects significantly the structural and morphological properties of a film. Electrodeposition and characterization of EuTe thin films onto different substrates such as stainless steel (SS), titanium (Ti), copper (Cu), fluorine-doped tin oxide (F:SnO2) covered glasses have been described. The deposition potentials have been estimated from the polarization curves. The reaction
N. S. Gaikwad; V. M. Nikale; C. H. Bhosale
Electrodeposition of EuSe thin films onto different substrates
Electrodeposition and characterization of EuSe thin films onto different substrates such as stainless steel (SS), Ti, Cu, fluorine-doped tin oxide (F-SnO2) covered glasses is described. The films have been prepared in potentiostatic mode using aqueous acidic electrolyte containing Eu and Se precursors at 70�C bath temperature and pH 4. The disodium salt of ethylenediaminetetraacetic acid (Na2-EDTA) is used as a
N. S. Gaikwad; C. H. Bhosale
Large-area SnO 2: F thin films by offline APCVD
In this paper, we reported the successful preparation of fluorine-doped tin oxide (FTO) thin films on large-area glass substrates (1245mm�635mm�3mm) by self-designed offline atmospheric pressure chemical vapor deposition (APCVD) process. The FTO thin films were achieved through a combinatorial chemistry approach using tin tetrachloride, water and oxygen as precursors and Freon (F-152, C2H4F2) as dopant. The deposited films were characterized
Yan Wang; Yucheng Wu; Yongqiang Qin; Zhihai Zhang; Chengwu Shi; Qingfeng Zhang; Changhao Li; Xiaohong Xia; Stanley Sun; Leon Chen
Spray pyrolytic deposition and characterization of SnS and SnS2 thin films
The spray pyrolysis technique is employed to prepare thin films of SnS on glass substrates and SnS2 on glass as well as fluorine doped tin oxide (FTO) coated glass substrates. The pyrolysis temperatures of SnS and SnS2 are 350 �C and 275 �C, respectively. The films are found to be n-type semiconductors. The SnS thin film is amorphous, whereas the
Effect of heavy doping in SnO2:F films
Thin films of fluorine-doped tin dioxide (SnO2:F) were deposited by a spray pyrolysis technique on soda lime glass substrates. Structural and electronic transport properties of the films deposited with different doping levels of fluorine (zero to 350 at %) were investigated. X-ray diffraction technique and Hall effect measurements were used for this work. Growth rate of the films was considerably
Chitra Agashe; S. S. Major
F-doped SnO 2 thin films grown on flexible substrates at low temperatures by pulsed laser deposition
Fluorine-doped tin oxide (SnO2:F) films were deposited on polyethersulfone plastic substrates by pulsed laser deposition. The electrical and optical properties of the SnO2:F films were investigated as a function of deposition conditions such as substrate temperature and oxygen partial pressure during deposition. High quality SnO2:F films were achieved under an optimum oxygen pressure range (7.4�8Pa) at relatively low growth temperatures
H. Kim; R. C. Y. Auyeung; A. Piqu�
Use of fluorine-doped tin oxide instead of indium tin oxide in highly efficient air-fabricated inverted polymer solar cells
The stability and efficiency of organic solar cells (OSCs) were improved using thermally stable fluorine-doped tin oxide (FTO) as the bottom electrode and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and TiO2 as the buffer layers. The TiO2 layer between FTO and the P3HT:PCBM active layer improved the interface characteristics for a better charge transfer. The PEDOT:PSS layer retarded the oxygen diffusion to the active layer. A maximum power conversion efficiency of 4.3% was obtained for the inverted structure of FTO/TiO2/P3HT:PCBM/PEDOT:PSS/Ag with a stable performance, and the cell retained over 65% of its initial efficiency after 500 h. Additionally, the OSCs were fabricated using all-solution based vacuum-free processes with screen printing for the Ag electrode and the results were comparable to the device that used an evaporated Ag electrode.
Baek, Woon-Hyuk; Choi, Mijung; Yoon, Tae-Sik; Lee, Hyun Ho; Kim, Yong-Sang
Effect of freon flow rate on tin oxide thin films deposited by chemical vapor deposition
High quality fluorine-doped tin oxide (SnO2:F) films on glass substrates were been prepared using chemical vapor deposition (CVD) method. The electrical properties, surface morphologies, structural properties and optical properties of the films were studied by varying the freon flow rates. The structure was analyzed by X-ray diffraction (XRD). Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to
Te-Hua Fang; Win-Jin Chang
Optical and electrochemical properties of Cu-doped NiO films prepared by electrochemical deposition
Cu-doped nickel oxide (NiO) thin films were prepared by electrochemial deposition (cathodic deposition) technique onto the fluorine doped tin oxide (F: SnO2; FTO) coated glass substrates from organic solutions. Effects of Cu content on the morphology, structure, optical and electrochromic properties of NiO films were investigated by means of scanning electron microscope (SEM), X-ray diffraction (XRD), ultraviolet�visible spectrophotometer (UV�vis) and
Lili Zhao; Ge Su; Wei Liu; Lixin Cao; Jing Wang; Zheng Dong; Meiqin Song
Preparation of Zn�In�S film electrodes using chemical bath deposition for photoelectrochemical applications
Ternary zinc�indium�sulfide film electrodes were fabricated on fluorine doped tin oxide coated glass substrates using chemical bath deposition. New procedures for the growth of Zn�In�S films are presented. The physical and photoelectrochemical properties of the samples were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), UV�vis spectroscopy, and a potentiostat. The XRD patterns and SEM images of samples reveal
Kong-Wei Cheng; Chia-Jui Liang
Discharge diagnosis and controlled deposition of SnO x :F films by DC-reactive sputtering from a metallic tin target
Fluorine-doped tin oxide (SnOx:F) films on glass substrates have been prepared by reactive magnetron DC-sputtering in Ar�O2�Freon plasma from a metallic tin target. We studied the relationship between the discharge characteristics and film properties and found the discharge conditions in which the films belong to the SnO2 or to the SnO stoichiometry, by proposing a phase diagram for this system.
A. Martel; F. Caballero-Briones; J. Fandi�o; R. Castro-Rodr??guez; P. Bartolo-P�rez; A. Zapata-Navarro; M. Zapata-Torres; J. L. Pe�a
Optical simulation of transmittance into a nanocrystalline anatase TiO 2 film for solar cell applications
Optical simulation has been employed, for the first time, for rigorous evaluation of transmittance into the TiO2 nanocrystalline film, entering from the fluorine-doped SnO2 (F-SnO2) coated glass side, in dye sensitized solar cells. The refractive index of the TiO2 film with various porosities was determined theoretically, and was in agreement with the data obtained by ellipsometric measurements. The simulation clearly
Yasuhiro Tachibana; Hitomi Y. Akiyama; Susumu Kuwabata
A study on low cost-high conducting fluorine and antimony-doped tin oxide thin films
Thin films of undoped, fluorine- and antimony-doped tin oxide on glass at 400�C was prepared by spray pyrolysis technique. Tin chloride (SnCl2), ammonium fluoride (NH4F), and antimony trichloride (SbCl3) were used as source for tin (Sn), fluorine (F), and antimony (Sb), respectively. To ensure the control of solution concentration on growth rate, fluorine-doped tin oxide (SnO2:F) thin films were first
Characterization on electron beam evaporated ?-MoO 3 thin films by the influence of substrate temperature
Electrochromic molybdenum oxide (MoO3) thin films were prepared by electron beam evaporation technique using the dry MoO3 pellets. The films were deposited on glass and fluorine doped tin oxide (SnO2:F or FTO) coated glass substrates at different substrate temperatures like room temperature (RT, 30�C), 100�C and 200�C. The influence of substrate temperature on the structural, surface morphological and optical properties
R. Sivakumar; R. Gopalakrishnan; M. Jayachandran; C. Sanjeeviraja
Viscous behavior of interfaces in fluorine-doped Si{sub 3}N{sub 4}/SiC composites
The influence of fluorine addition on the grain/phase boundary structures and their viscous behavior at high temperature were systematically investigated in Si{sub 3}N{sub 4}/SiC composites. As a reference, a simple system densified by hot isostatic pressing (HIP) and containing only SiO{sub 2} at the boundaries was selected for this basic investigation. In addition, increasing amounts of F dopant were incorporated into the composite bodies by adding Teflon during the mixing procedure of the raw powders and then pre-firing the mixture under high vacuum at 1,200 C. Analytical transmission electron microscopy showed that fluorine remained localized at the grain boundary films and triple points, constituting an amount up to a few percent by weight of the intergranular glassy-SiO{sub 2} phase. Detailed structural characterizations of both grain and phase boundaries were performed by using high-resolution electron microscopy (HREM) and atomic force microscopy (AFM). The high-temperature mechanical behavior of the undoped and F-doped SiO{sub 2} phases was characterized by both measurements of torsional creep rate and variation of internal friction at temperatures up to 1,600 C. F-doped materials showed creep rates several orders of magnitude higher compared to the undoped sample and damping temperature curves markedly shifted to lower temperature values. According to the above set of microstructural and mechanical data, the inherent viscosity of the SiO{sub 2} intergranular phase could be quantitatively evaluated and the viscous-sliding mechanism under stress modeled.
Pezzotti, G. [Toyohashi Univ. of Technology, Hibarigaoka, Toyohashi (Japan). Dept. of Materials Science] [Toyohashi Univ. of Technology, Hibarigaoka, Toyohashi (Japan). Dept. of Materials Science; Ota, K. [Osaka Univ., Ibaraki, Osaka (Japan). Inst. of Scientific and Industrial Research] [Osaka Univ., Ibaraki, Osaka (Japan). Inst. of Scientific and Industrial Research; Kleebe, H.J. [Univ. Bayreuth (Germany). Inst. fur Materialforschung] [Univ. Bayreuth (Germany). Inst. fur Materialforschung; Okamoto, Y.; Nishida, T. [Kyoto Inst. of Tech., Matsugasaki, Kyoto (Japan). Dept. of Materials] [Kyoto Inst. of Tech., Matsugasaki, Kyoto (Japan). Dept. of Materials
Studies on Spray Deposited SnO2, Pd:SnO2 and F:SnO2 Thin Films for Gas Sensor Applications
Undoped tin oxide (TO), palladium?doped tin oxide (PTO) and fluorine?doped tin oxide (FTO) thin films have been prepared by spray pyrolysis method, under optimized conditions. Transmission measurement of the TO, PTO and FTO films have been studied in the UV?Visible region. Band gap energy evaluated from the spectral data lies between 3.15 eV and 3.8 eV. The X?ray diffraction analysis
N. Sankara Subramanian; B. Santhi; S. Sundareswaran; K. S. Venkatakrishnan
Surfactant-mediated growth of nanostructured zinc oxide thin films via electrodeposition and their photoelectrochemical performance
Zinc oxide (ZnO) thin films were electrodeposited from an aqueous zinc acetate solution onto fluorine-doped thin oxide (FTO) coated conducting glass substrates. The effect of organic surfactants like polyvinyl pyrrolidone (PVP), sodium dodecyl sulfate (SDS), polyethylene glycol (PEG), ethylene glycol (EG) and polyvinyl alcohol (PVA) on their structural, morphological, optical and photoelectrochemical properties was studied. The x-ray diffraction patterns revealed
A I Inamdar; S H Mujawar; V Ganesan; P S Patil
Transparent Conductors and Barrier Layers for Thin Film Solar Cells:
This report describes the research undertaken to increase the efficiency of thin-film solar cells based on amorphous silicon in the so-called''superstrate structure'' (glass front surface/transparent electrically conductive oxide (TCO)/pin amorphous silicon/metal back electrode). The TCO layer must meet many requirements: high optical transparency in the wavelength region from about 350 to 900 nm, low electrical sheet resistance, stability during handling and deposition of the subsequent layers and during use, a textured (rough) surface to enhance optical absorption of red and near-infrared light, and low-resistance electrical contact to the amorphous silicon p-layer. Fluorine-doped tin oxide has been the TCO used in most commercial superstrate amorphous silicon cells. Fluorine-doped zinc oxide (ZnO:F) was later shown to be even more transparent than fluorine-doped tin oxide, as well as being more resistant to the strongly reducing conditions encountered during the deposition of amorphous silicon. Solar cells based on ZnO:F showed the expected higher currents, but the fill factors were lower than standard cells grown on tin oxide, resulting in no consistent improvement in efficiency. This problem was recently mitigated by using a new proprietary p/buffer layer combination developed at BP Solar.
Gordon, R. G.; Broomhall-Dillard, R.; Liu, X.; Pang, D.; Barton, J.
Room temperature electrodeposition and characterization of bismuth ferric oxide (BFO) thin films from aqueous nitrate bath
Bismuth ferric oxide (BFO) thin films were prepared on fluorine doped tin oxide (FTO) coated glass substrates using electrodeposition method from aqueous nitrate bath at room temperature. The various preparative parameters, such as bath composition, current density, deposition time, etc were optimized to get good quality BFO thin films. The structural, surface morphological, optical and dielectrical properties of the films were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), optical absorption and dielectric measurement techniques. The results show that electrodeposition method allows to synthesis BFO films. The films are free from pinholes and cracks. The magnitudes of dielectric constant and loss tangent showed inverse frequency dependence.
Gujar, T. P.; Shinde, V. R.; Kulkarni, S. S.; Pathan, H. M.; Lokhande, C. D.
Performance degradation analysis of high-voltage biased thin-film PV modules in hot and humid conditions
Considerable degradation has been observed in negatively-biased, framed a-Si:H thin-film photovoltaic (PV) modules fabricated with earlier generation fluorine-doped tin oxide (SnO2:F) transparent conducting oxide (TCO) layers on superstrate glass. These modules were tested under high-voltage (HV) bias in a hot and humid climate and leakage currents (LC) from module frames to ground were monitored. Modules negatively-biased at -600 V, -300
N. G. Dhere; V. V. Hadagali; K. Jansen
Fourier transformation infrared spectrum studies on the role of fluorine in SnO2:F films
In this letter we employed Fourier transform infrared spectroscopy (FTIR) to study fluorine-doped SnO2 films deposited by spray pyrolysis. The role of oxygen vacancy and substitution of fluorine for oxygen are demonstrated by FTIR. It is found that at low doping levels, fluorine ions prefer to occupy oxygen positions in SnO2 lattice. While beyond a certain doping level, fluorine ions
FTO films deposited in transition and oxide modes by magnetron sputtering using tin metal target.
Fluorine-doped tin oxide (FTO) films were prepared by pulsed DC magnetron sputtering with a metal Sn target. Two different modes were applied to deposit the FTO films, and their respective optical and electrical properties were evaluated. In the transition mode, the minimum resistivity of the FTO film was 1.63�10(-3)????cm with average transmittance of 80.0% in the visible region. Furthermore, FTO films deposited in the oxide mode and mixed simultaneously with H2 could achieve even lower resistivity to 8.42�10(-4)????cm and higher average transmittance up to 81.1% in the visible region. PMID:24514207
Liao, Bo-Huei; Chan, Shih-Hao; Lee, Cheng-Chung; Kuo, Chien-Cheng; Chen, Sheng-Hui; Chiang, Donyau
Atomic layer deposition of Al2O3 on V2O5 xerogel film for enhanced lithium-ion intercalation stability
V2O5 xerogel films were fabricated by casting V2O5 sols onto fluorine-doped tin oxide glass substrates at room temperature. Five, ten and twenty atomic layers of Al2O3 were grown onto as-fabricated films respectively. The bare film and Al2O3-deposited films all exhibited hydrous V2O5 phase only. Electrochemical impedance spectroscopy study revealed increased surface charge-transfer resistance of V2O5 films as more Al2O3 atomic
Dawei Liu; Yanyi Liu; Stephanie L. Candelaria; Guozhong Cao; Jun Liu; Yoon-Ha Jeong
Synthesis of cauliflower-like ZnO�TiO 2 composite porous film and photoelectrical properties
A series of cauliflower-like TiO2�ZnO composite porous films with various molar ratios of Zn\\/Ti were prepared by the screen printing technique on the fluorine-doped SnO2 (FTO) conducting glasses. The composite films were characterized by field-emission scanning electron microscopy (FE-SEM), X-ray energy-dispersive spectrometry (EDS) and UV�vis transmittance spectrum. The results showed composite film electrode had a novel cauliflower-like morphology, which could
Yinhua Jiang; Yun Yan; Wenli Zhang; Liang Ni; Yueming Sun; Hengbo Yin
Studies on the structural and electrical properties of F-doped SnO 2 film prepared by APCVD
Fluorine-doped tin oxide films (SnO2:F, FTO) were deposited by atmosphere pressure chemical vapor deposition (APCVD) on Na�Ca�Si glass coated with a diffusion barrier layer of SiOxCy. The effects of post-heating time at 700�C on the structural and electrical properties of SnO2:F films were investigated. The results showed that SnO2:F films were polycrystalline with tetragonal SnO2 structure, SnO phase was present
Jingkai Yang; Wenchang Liu; Lizhong Dong; Yuanxun Li; Chuan Li; Hongli Zhao
Acicular crystal-assembled TiO 2 thin films and their deposition mechanism
Acicular crystal-assembled TiO 2 thin films were prepared on fluorine-doped tin oxide (FTO) substrates in aqueous solutions. They consisted of anatase crystals grown along the c-axis, which caused high c-axis orientation in X-ray diffraction patterns and electron diffraction patterns. Morphologies of TiO 2 crystals were controlled by growth conditions to fabricate several types of TiO 2 thin films. Furthermore, deposition mechanism of acicular crystals was investigated by comparison of crystal morphologies deposited for different immersion periods using solution aging method.
Masuda, Yoshitake; Kato, Kazumi
Transparent conducting F-doped SnO 2 thin films grown by pulsed laser deposition
Transparent conducting fluorine-doped tin oxide (SnO2:F) films have been deposited on glass substrates by pulsed laser deposition. The structural, electrical and optical properties of the SnO2:F films have been investigated as a function of F-doping level and substrate deposition temperature. The optimum target composition for high conductivity was found to be 10�wt.% SnF2+90�wt.% SnO2. Under optimized deposition conditions (Ts=300��C, and
Temperatureprogrammed desorption of F-doped SnO 2 films depositedby inverted pyrosol technique
Fluorine-doped tin dioxide\\u000a (FTO) films were deposited on silicon wafers by inverted pyrosol technique\\u000a using solutions with different doping concentration (F\\/Sn=0.00, 0.12, 0.75\\u000a and 2.50). The physical and electrical properties of the deposited films were\\u000a analyzed by SEM, XRF, resistivity measurement by four-point-probe method and\\u000a Hall coefficient measurement by van der Pauw method. The electrical properties\\u000a showed that the FTO
S. Aukkaravittayapun; C. Thanachayanont; T. Theapsiri; W. Veerasai; Y. Sawada; T. Kondo; S. Tokiwa; T. Nishide
Optostructural and electrical studies on electrodeposited Indium doped ZrS 2 thin films
Electrochemical deposition and characterization of indium doped zirconium disulphide (In:ZrS2) thin films deposited onto stainless steel and fluorine doped tin oxide (FTO) coated conducting glass plates from an aqueous bath containing ZrO(NO3)2, Na2S2O3�5H2O and In2(SO4)3 is discussed in present manuscript. The prepared films were characterized by X-ray diffraction analysis (XRD), energy dispersive X-ray analysis (EDS), scanning electron microscopy (SEM) and
A. M. Sargar; N. S. Patil; S. R. Mane; S. N. Gawale; P. N. Bhosale
The origin of haze in CVD tin oxide thin films
The origin of haze was investigated in antimony-doped tin oxide thin films, and in double-stack thin films of fluorine-doped tin oxide/antimony-doped tin oxide, both deposited by chemical vapor deposition onto soda-lime-silica float glass substrates. These transparent conductive oxide thin films are of great importance in the production of solar control architectural glazing units. Therefore, understanding the origins of haze is necessary to the development of coated, IR-reflecting glass windows with low overall haze levels. Haze measurements of as-prepared and polished samples were correlated with surface roughness and concentration of internal hole defects. Surface roughnesses were evaluated by atomic force microscopy, and characterized by estimated RMS values. In thin tin oxide films (<2000 �) internal hole defects caused haze, while in thick tin oxide films (>4000 �) surface roughness was the primary source of haze.
Szanyi, J�nos
TiO2/CdSe core-shell nanofiber film for photoelectrochemical hydrogen generation.
We report on a novel core-shell TiO2/CdSe nanofiber photoanode for photoelectrochemical hydrogen generation. The core-shell nanofiber films, with a hierarchical network structure, are prepared on fluorine-doped tin oxide coated substrates via electrospinning pyrolysis and chemical bath deposition. The hierarchical network structure shows significantly improved photoelectrochemical properties due, we believe, to possessing more active sites for the oxidation reaction and a larger TiO2/CdSe interface area for photogenerated charges' separation. The synthesis details are discussed to provide a generic route for preparing other similar photoanodes with hierarchical network structures. PMID:24876070
Liu, Ya; Zhao, Liang; Li, Mingtao; Guo, Liejin
Electrochemical deposition of silver nanoparticles on TiO 2/FTO thin films
Silver nanoparticles were deposited on titanium oxide IV (TiO 2) thin films supported on FTO (fluorine-doped tin oxide IV) glass using a double pulse electrochemical deposition method. A systematic study of particle nucleation and growth is presented as a function of applied potential and time. Samples were analyzed by grazing-angle X-ray diffraction (GIXRD) technique and morphology was observed using Scanning Electron Microscopy and Energy Dispersive Spectroscopy device (SEM-EDS). Our results confirm the possibility of controlled electrochemical homogeneous deposition of metallic silver particles over TiO 2 surface, which exhibit a potential application in catalytic processes.
D�vila-Mart�nez, Rosa E.; Cueto, Luisa F.; S�nchez, Eduardo M.
A nanocrystalline hematite film prepared from iron(III) chloride precursor
This paper deals with a simple and low-cost method developed to deposit hematite (?-Fe2O3) layers on a fluorine-doped tin oxide (FTO\\/F:SnO2) substrate by thermal decomposition of solid iron(III) chloride hexahydrate (FeCl3?6H2O). Deposition procedure takes place through chemical intermediate iron(III) oxide chloride (FeOCl) film. A crucial influence of atmosphere dynamics involved in the calcination process of FeOCl has been observed. As-deposited
Jiri Frydrych; Libor Machala; Martin Hermanek; Ivo Medrik; Miroslav Mashlan; Jiri Tucek; Jiri Pechousek; Virender K. Sharma
TiO2/CdSe core-shell nanofiber film for photoelectrochemical hydrogen generation
We report on a novel core-shell TiO2/CdSe nanofiber photoanode for photoelectrochemical hydrogen generation. The core-shell nanofiber films, with a hierarchical network structure, are prepared on fluorine-doped tin oxide coated substrates via electrospinning pyrolysis and chemical bath deposition. The hierarchical network structure shows significantly improved photoelectrochemical properties due, we believe, to possessing more active sites for the oxidation reaction and a larger TiO2/CdSe interface area for photogenerated charges' separation. The synthesis details are discussed to provide a generic route for preparing other similar photoanodes with hierarchical network structures.
Characterization and comparison of optically transparent conducting films
Textured tin oxide films with high light-trapping efficiency, high electrical conductivity and high transparency were successfully grown at high rates by chemical vapor deposition (CVD). This process has achieved large-scale commercial production of substrates for amorphous silicon solar cells. Highly transparent and highly conductive films of fluorine-doped zinc oxide were formed by a new CVD process. Increases in the texture (light-trapping) and growth rate are needed to make this a practical process for making substrates for solar cells. Decreases in deposition temperature are needed to make successful back contacts. A hybrid transparent conducting oxide (TCO) consisting of textured tin oxide covered with a thin, smooth fluorine-doped zinc oxide layer combines the best features of these two materials. It shows efficient light-trapping because of the textured tin oxide, combined with the good resistance of zinc oxide to the hydrogen plasma used to deposit the amorphous silicon. Highly conductive and reflective titanium nitride was deposited under conditions mild enough to form back contacts on amorphous silicon solar cells. Actual cells will be coated and tested in the next contract period. Further optimization of the deposition conditions for these materials should be carried out in collaboration with solar cell manufacturers.
Gordon, R. G.
Optimization of Transparent Electrode for Solar Cell and Chemical Vapor Deposition of Amorphous Silicon. Final Technical Report, 15 September 1980-30 March 1983.
National Technical Information Service (NTIS)
A film of fluorine-doped tin oxide can meet all these requirements. A new process for depositing fluorine-doped tin oxide films was optimized. Further optimization of the transparent electrode films has been accomplished, with increasing substrate tempera...
R. G. Gordon J. Proscia F. Ellis S. Kurtz
Double junction photoelectrochemical solar cells based on Cu2ZnSnS4/Cu2ZnSnSe4 thin film as composite photocathode
A solvothermal method was used to synthesize Cu2ZnSnS4 (CZTS) and Cu2ZnSnSe4 (CZTSe) nanoparticles. CZTS/CZTSe bilayer films have been fabricated via a layer-by-layer blade coating process on the fluorine dope tin oxide (FTO) substrates. We converted conventional dye-sensitized solar cells (DSSCs) into double junction photoelectrochemical solar cells with the replacement of the Pt-coated counter electrode with the as-prepared films as composite photocathodes. Compared with conventional DSSCs, the cells show an increased short circuit current and power conversion efficiency.
Zhu, L.; Qiang, Y. H.; Zhao, Y. L.; Gu, X. Q.
Electrochromic properties of vanadium oxide thin films prepared by PSPT: Effect of substrate temperature
Electrochromic vanadium oxide (V2O5) thin films were deposited onto glass and fluorine doped tin oxide (FTO) coated glass substrates from methanolic vanadium chloride solution by pulsed spray pyrolysis technique (PSPT). The films were synthesized at different substrate temperatures ranging from 350�C-450�C with a temperature step of 50�C. The structural, morphological, optical and electrochromic properties of the synthesized films were investigated. The films were polycrystalline with tetragonal crystal structure. Scanning electron microscopy reveals compact morphology at high temperature. All films exhibited cathodic electrochromism in lithium containing electrolyte (0.5 M LiClO4 + Propylene Carbonate). Maximum coloration efficiency (CE) 15.16 cm2C-1, was observed for the films deposited at 350�C.
Patil, C. E.; Jadhav, P. R.; Tarwal, N. L.; Deshmukh, H. P.; Karanjakar, M. M.; Wali, A. A.; Patil, P. S.
Hydrogenated TiO2 film for enhancing photovoltaic properties of solar cells and self-sensitized effect
Hydrogenated TiO2 film was obtained by annealing TiO2 film at 350 �C for 2 h with hydrogen, and TiO2 films were prepared by screen printing on fluorine-doped tin oxide glass. Structural characterization by X-ray diffraction and electron microscopy did not show obvious difference between hydrogenated TiO2 film and pristine TiO2 film. Through optical and electrochemical characterization, the hydrogenated TiO2 film showed enhanced absorption and narrowed band gap, as well as reduced TiO2 surface impedance and dark current. As a result, an obviously enhanced photovoltaic effect was observed in the solar cell with hydrogenated TiO2 as photoanode without adding any dye due to the self-sensitized effect of hydrogenated TiO2 film, which excited electrons injecting internal conduction band of TiO2 to generate more photocurrent.
He, Hongcai; Yang, Kui; Wang, Ning; Luo, Feifei; Chen, Haijun
Electrodeposition of Ga--O Thin Films from Aqueous Gallium Sulfate Solutions
Ga--O based thin films were electrodeposited on fluorine-doped tin oxide (FTO)-coated glass substrate at room temperature from aqueous gallium sulfate solution with hydrogen peroxide (H2O2). Effects of different deposition parameters such as deposition voltage, amount of H2O2 and deposition time were investigated and presented. Nearly smooth and crack-free morphologies were attained at -1.0 V vs SCE deposition potential. As-deposited films showed O to Ga ratio of 2.0, which signified GaOOH formation. Thermal annealing of the as-deposited films in ambient air at 500--600 �C reduced the O/Ga ratio closer to stoichiometric gallium oxide (Ga2O3) and retained the morphology of Ga--O thin films. As-prepared films with �0.2 ?m thickness had 80% transparency in the visible wavelength range.
Vequizo, Junie Jhon M.; Ichimura, Masaya
CuIn1-XAlXSe2 Thin Films Grown By Electrodeposition
We have grown CuIn1-xAlxSe2 thin films on fluorine doped tin oxide glass at a constant deposition potential of -650 mV by the electrodeposition technique. The electrochemical bath from which the CuIn1-XAlXSe2 (CIAS) thin films were grown was made up of a mixture of aqueous solutions of 0.025 M CuCl2, 0.05 M InCl3, 0.05 M AlCl3 and 0.025 M SeO2. Ethylene-diamine-dihydrochloride (EDC) was used as a complexing agent which was found to reduce the particle size of the CIAS thin films. The electrodeposited films were characterized using XRD, SEM and EDAX. The results show that single phase CuIn1-xAlxSe2 films with Al content x around 0.28 and having good stoichiometry can be produced.
Prasher, Dixit; Sharma, Ranjana; Sharma, Ashok K.; Rajaram, P.
Photoelectrochemical characterization of nanocrystalline thin-film Cu?ZnSnS? photocathodes.
Cu?ZnSnS? (CZTS) nanocrystals, synthesized by a hot injection solution method, have been fabricated into thin films by dip-casting onto fluorine doped tin oxide (FTO) substrates. The photoresponse of the CZTS nanocrystal films was evaluated using absorbance measurements along with photoelectrochemical methods in aqueous electrolytes. Photoelectrochemical characterization revealed a p-type photoresponse when the films were illuminated in an aqueous Eu(3+) redox electrolyte. The effects of CZTS stoichiometry, film thickness, and low-temperature annealing on the photocurrents from front and back illumination suggest that the minority carrier diffusion and recombination at the back contact (via reaction of photogenerated holes with Eu(2+) produced from photoreduction by minority carriers) are the main loss mechanisms in the cell. Low-temperature annealing resulted in significant increases in the photocurrents for films made from both Zn-rich and stoichiometric CZTS nanocrystals. PMID:21194208
Riha, Shannon C; Fredrick, Sarah J; Sambur, Justin B; Liu, Yuejiao; Prieto, Amy L; Parkinson, B A
Fabrication of hydrophobic surface of titanium dioxide films by successive ionic layer adsorption and reaction (SILAR) method
Titanium dioxide (TiO 2) films were fabricated on fluorine doped tin oxide (FTO) coated glass substrate using successive ionic layer adsorption and reaction (SILAR) method. The X-ray diffraction, scanning electron microscopy, transmission electron microscopy, optical absorption and contact angle measurement were applied to study the structural, surface morphological, optical and surface wettability properties of the as-deposited and annealed TiO 2 films. The X-ray diffraction studies revealed both as-deposited and annealed TiO 2 films are amorphous. Irregular shaped spherical grains of random size and well covered to the fluorine doped tin oxide coated glass substrates were observed from SEM studies with some cracks after annealing. The optical band gap values of virgin TiO 2, annealed, methyl violet and rose bengal sensitized TiO 2 were found to be 3.6, 3.5, 2.87 and 2.95 eV, respectively. Surface wettability studied in contact with liquid interface, showed hydrophobic nature as water contact angles were greater than 90�. The adsorption of dyes, as confirmed by the photographs, is one of the prime requirements for dye sensitized solar cells (DSSC).
More, A. M.; Gunjakar, J. L.; Lokhande, C. D.; Joo, Oh Shim
Thin films of undoped, fluorine- and antimony-doped tin oxide on glass at 400 �C was prepared by spray pyrolysis technique. Tin chloride (SnCl 2), ammonium fluoride (NH 4F), and antimony trichloride (SbCl 3) were used as source for tin (Sn), fluorine (F), and antimony (Sb), respectively. To ensure the control of solution concentration on growth rate, fluorine-doped tin oxide (SnO 2:F) thin films were first prepared with different amount of tin precursor, in the range of 5-12 g, which has resulted in deposition of films with different thickness values. The optimum amount of tin precursor found from this study (11 g) was fixed constant for preparing SnO 2 films with different doping levels of F and Sb. From the X-ray diffraction analyses, it is understood that the preferred orientation of SnO 2:F films is dependent on their thickness and the solution concentration. The variation in the solution concentration and orientation of the films was reflected in their morphology as examined by scanning electron microscopy (SEM) and atomic force microscopy (AFM). SEM studies showed that the variation in the solution concentration lead to different grain shapes for different orientations. The AFM study showed that the RMS roughness of undoped films reduced considerably from 86 to 24 nm due to fluorine doping (15 wt.%), whereas the antimony doping (2 wt.%) has no significance effect on RMS roughness (93 nm). The electrical properties of the films were examined by a Hall measurements setup in van der Pauw configuration. A minimum sheet resistance of 1.75 and 2.17 ?/ ? were obtained for F and Sb doped films, respectively. From the optical studies, it is found that the transmittance of undoped films increased from 42% to a maximum 85% on 30 wt.% fluorine doping, whereas that has been decreased to a minimum of 12% on 4 wt.% antimony doping (800 nm). A discussion on the effect of type of dopants and their concentration on the structural, electrical and optical properties of the SnO 2 film have been presented.
Elangovan, E.; Ramamurthi, K.
Effect of growth potential on the electrodeposition of CIS thin films
Thin films of copper indium diselenide (CIS) were prepared in aqueous bath by low-cost potentiostatic electrodeposition technique onto Fluorine doped tin oxide substrates. The deposition potential was optimized using cyclic voltammetry study in a ternary Cu-In-Se system. The films were characterized systematically with the aid of UV-Vis spectroscopy, IV measurements, X-ray diffraction, Scanning electron microscopy and Energy dispersive X-ray analysis. CIS films deposited for different growth potential shows the tetragonal structure with (112) preferential orientation. Annealing of the films at temperature 400�C not only improves the crystallinity of layers, but it also increases the grain size, which is suitable for the development of high efficiency solar cells.
Dhanwate, Vishakha N.; Chaure, N. B.
Reactive ballistic deposition of alpha-Fe2O3 thin films for photoelectrochemical water oxidation.
We report the preparation of alpha-Fe2O3 electrodes using a technique known as reactive ballistic deposition in which iron metal is evaporatively deposited in an oxygen ambient for photoelectrochemical (PEC) water oxidation. By manipulating synthesis parameters such as deposition angle, film thickness, and annealing temperature, we find that it is possible to optimize the structural and morphological properties of such films in order to improve their PEC efficiency. Incident photon to current conversion efficiencies (IPCE) are used to calculate an AM1.5 photocurrent of 0.55 mA/cm(2) for optimized films with an IPCE reaching 10% at 420 nm in 1 M KOH at +0.5 V versus Ag/AgCl. We also note that the commonly observed low photoactivity of extremely thin hematite films on fluorine-doped tin oxide substrates may be improved by modification of annealing conditions in some cases. PMID:20361756
Hahn, Nathan T; Ye, Heechang; Flaherty, David W; Bard, Allen J; Mullins, C Buddie
Resistance switching behaviors of V-doped La0.67Ca0.33MnO3 thin films on F-doped SnO2 conducting glass
V-doped La0.67Ca0.33MnO3 (LCMO) thin films were prepared on fluorine-doped SnO2 (FTO) conducting glass substrates with a sol-gel technique. The resistance switching properties of Au\\/V:LCMO\\/FTO heterostructures investigated by electrochemical workstation showed reproducible resistive switching behaviors at room temperature. The interactions between nonlattice (mobile) oxygen and oxygen vacancies and\\/or the cationic vacancies contributed to the carrier transport of the LCMO layer sandwiched
Ting Zhang; Hongju Chen; Manman Ni; Zhaohui Su; Weifeng Zhang
CuInSe2 thin films by non-aqueous electrodeposition
The electrochemical deposition of CuInSe2 (CIS) thin films on fluorine doped tin oxide (FTO) coated glass substrates from non-aqueous electrolyte are presented. The structural and morphological properties were studied. For the codeposition of Cu, In and Se with ideal stoichiometry, the suitable potential range was found to be -1.1 V to -1.3 V versus Ag/AgCl reference electrode using cyclic voltammetry (CV) experiment. X-ray result shows that the CIS films obtained from non-aqueous bath are highly crystalline. The surface morphology of CIS films were studied using scanning probe microscopy. The grain sizes of ~ 2 to 3 ?m and ~ 0.5 to 1 ?m were observed for the CIS layers deposited from non-aqueous and aqueous bath.
Chaure, N. B.
Zn-doped nanocrystalline TiO2 films for CdS quantum dot sensitized solar cells.
Quantum dot-sensitized solar cells based on Zn-doped TiO(2) (Zn-TiO(2)) film photoanode and polysulfide electrolyte were fabricated. Zn-TiO(2) nanoparticles were obtained via a hydrothermal method and screen printed on the fluorine-doped tin oxide glass to prepare the photoanode. The structure, morphology and impedance of the Zn-TiO(2)/CdS film and the photovoltaic performance of the Zn-TiO(2)/CdS cell were investigated. It was found that the photovoltaic efficiency was improved by 24% when the Zn-TiO(2) film was adopted as the photoanode of CdS QDSSCs instead of only the TiO(2) layer. The improvement was ascribed to the reduction of electron recombination and the enhancement of electron transport in the TiO(2) film by Zn doping. PMID:20648354
Zhu, Guang; Cheng, Zujun; Lv, Tian; Pan, Likun; Zhao, Qingfei; Sun, Zhuo
Thin film cadmium telluride and zinc phosphide solar cells
The deposition of cadmium telluride films by direct combination of the cadmium and tellurium vapor on foreign substrates is described. Nearly stoichiometric p-type cadmium telluride films and arsenic-doped p-type films were prepared reproducibly. Major efforts were directed to the deposition and characterization of heterojunction window materials, indium tin oxide, fluorine-doped tin oxide, cadmium oxide, and zinc oxide. A number of heterojunction solar cells were prepared, and the best thin-film ITO/CdTe solar cells had an AMI efficiency of about 7.2%. Zinc phosphide films were deposited on W/steel substrated by the reaction of zinc and phosphine in a hydrogen flow. Films without intentional doping had an electrical resistivity on the order of 10(6) ohm-cm, and this resistivity may be reduced to about 5 x 10(4) ohm-cm by adding hydrogen chloride or hydrogen bromide to the reaction mixture. Lower resistivity films are deposited by adding a controlled amount of silver nitrate solution on to the substrate surface. Major efforts are directed to the deposition of low-resistivity zinc selenide to prepare ZnSe/An3P2 heterojunction thin-film solar cells. The zinc selenide films deposited by vaccum evaporation and chemical vapor deposition techniques are all of high resistivity.
Chu, T.
This report describes research performed from June 1982 to October 1983 on the deposition of cadmium telluride films by direct combination of the cadmium and tellurium vapor on foreign substrates. Nearly stoichiometric p-type cadmium telluride films and arsenic-doped p-type films have been prepared reproducibly. Major efforts were directed to the deposition and characterization of heterojunction window materials, indium tin oxide, fluorine-doped tin oxide, cadmium oxide, and zinc oxide. A number of heterojunction solar cells were prepared, and the best thin-film ITO/CdTe solar cells had an AMl efficiency of about 7.2%. Zinc phosphide films were deposited on W/steel substrates by the reaction of zinc and phosphine in a hydrogen flow. Films without intentional doping had an electrical resistivity on the order of 10/sup 6/ ohm-cm, and this resistivity may be reduced to about 5 x 10/sup 4/ ohm-cm by adding hydrogen chloride or hydrogen bromide to the reaction mixture. Lower resistivity films were deposited by adding a controlled amount of silver nitrate solution on to the substrate surface. Major efforts were directed to the deposition of low-resistivity zinc selenide in order to prepare ZnSe/An/sub 3/P/sub 2/ heterojunction thin-film solar cells. However, zinc selenide films deposited by vacuum evaporation and chemical vapor deposition techniques were all of high resistivity.
Perovskite Solar Cells Based on Nanocolumnar Plasma-Deposited ZnO Thin Films.
ZnO thin films having a nanocolumnar microstructure are grown by plasma-enhanced chemical vapor deposition at 423 K on pre-treated fluorine-doped tin oxide (FTO) substrates. The films consist of c-axis-oriented wurtzite ZnO nanocolumns with well-defined microstructure and crystallinity. By sensitizing CH3 NH3 PbI3 on these photoanodes a power conversion of 4.8?% is obtained for solid-state solar cells. Poly(triarylamine) is found to be less effective when used as the hole-transport material, compared to 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-OMeTAD), while the higher annealing temperature of the perovskite leads to a better infiltration in the nanocolumnar structure and an enhancement of the cell efficiency. PMID:24643984
Ramos, F Javier; L�pez-Santos, Maria C; Guill�n, Elena; Nazeeruddin, Mohammad Khaja; Gr�tzel, Michael; Gonzalez-Elipe, Agustin R; Ahmad, Shahzada
Structural, compositional and morphological studies of thermally evaporated MoO3 thin films
Molybdenum oxide (MoO3) nanostructures were grown on different substrates such as glass, indium tin oxide coated glass and fluorine doped glass by thermal evaporation of MoO3 powder at elevated temperature (750�C) using tube furnace without any catalyst and then by subsequent O2/Ar flow rate. The morphology, composition and crystal structure were examined by using SEM, EDAX, Laser Raman and XRD. The films are polycrystalline with well-defined diffraction peaks and it consist of MoO3 with ?-orthorhombic structure. The synthesized MoO3 belongs to different morphologies, generally nanobelt and nanohunk structures. The EDAX spectra confirm the films are composed only of Mo and O atoms. The O/Mo ratio is nearly equal to 3 that shows the stoichiometry of MoO3.
Senthilkumar, R.; Ravi, G.
The effect of the film thickness and doping content of SnO2:F thin films prepared by the ultrasonic spray method
This paper reports on the effects of film thickness and doping content on the optical and electrical properties of fluorine-doped tin oxide. Tin (II) chloride dehydrate, ammonium fluoride dehydrate, ethanol and HCl were used as the starting materials, dopant source, solvent and stabilizer, respectively. The doped films were deposited on a glass substrate at different concentrations varying between 0 and 5 wt% using an ultrasonic spray technique. The SnO2:F thin films were deposited at a 350 �C pending time (5, 15, 60 and 90 s). The average transmission was about 80%, and the films were thus transparent in the visible region. The optical energy gap of the doped films with 2.5 wt% F was found to increase from 3.47 to 3.89 eV with increasing film thickness, and increased after doping at 5 wt%. The decrease in the Urbach energy of the SnO2:F thin films indicated a decrease in the defects. The increase in the electrical conductivity of the films reached maximum values of 278.9 and 281.9 (?�cm)-1 for 2.5 and 5 wt% F, respectively, indicating that the films exhibited an n-type semiconducting nature. A systematic study on the influence of film thickness and doping content on the properties of SnO2:F thin films deposited by ultrasonic spray was reported.
Rahal, Achour; Benramache, Said; Benhaoua, Boubaker
Synthesis and characterization of Cu2ZnSnS4 thin films by SILAR method
Semiconducting Cu2ZnSnS4 (CZTS) material has been receiving a great technological interest in the photovoltaic industry because of its low-cost non-toxic constituents, ideal direct band gap as a absorber layer and high absorption coefficient. CZTS thin films have been successfully deposited onto the fluorine-doped tin oxide/glass (glass/FTO) substrates coated glass substrates using successive ionic layer adsorption and reaction (SILAR) method and investigated for photoelectrochemical conversion (PEC) of light into electricity. The best solar cell sample showed an open-circuit voltage of 390 mV, a short-circuit current density of 636.9 ?A/cm2, a fill factor of 0.62 and an efficiency of 0.396% under irradiation of 30 mW/cm2. Preliminary results obtained for solar cells fabricated with this material are promising.
Mali, Sawanta S.; Shinde, Pravin S.; Betty, Chirayath A.; Bhosale, Popatrao N.; Oh, Young Woo; Patil, Pramod S.
Hierarchical growth of SnO2 nanostructured films on FTO substrates: structural defects induced by Sn(ii) self-doping and their effects on optical and photoelectrochemical properties.
Direct hydrothermal growth of Sn(ii)-doped SnO2 films on fluorine-doped tin oxide (FTO) substrates results in the formation of upstanding SnO2 nanosheet arrays covered by hierarchical SnO2 nanoflowers. The n-type semiconductor films show extended photoresponse in the visible spectrum arising from the coexistence of Sn(ii) dopant ions and oxygen vacancies in these hierarchical SnO2 nanostructures, which leads to a narrowed bandgap. Photoluminescence spectroscopy revealed that the emission in the UV, blue and red spectral ranges is related to the evolution of Sn(ii) dopants and oxygen vacancies with annealing temperature, whereas oxygen vacancies are mostly responsible for visible emission. The Sn(ii)-doped SnO2 films show higher photocurrent when sensitized with narrow bandgap CdS nanoparticles, serving as efficient electron acceptors. PMID:24781385
Wang, Hongkang; Kalytchuk, Sergii; Yang, Haihua; He, Lifang; Hu, Chenyan; Teoh, Wey Yang; Rogach, Andrey L
Using I�V characteristics to investigate selected contacts for SnO2:F thin films
Fluorine doped tin oxide (SnO2:F) thin films were prepared on glass substrates by the spray pyrolysis (SP) technique at different substrate temperatures between 380-480 �C. The microstructure of the films was explored using scanning electron microscope observations. An investigation of selected contacts for the films was performed through the analysis of the I-V measurements which were taken in the dark at room temperature. Indium, aluminum and silver were selected as contacts where two strips of each metal were vacuum-evaporated on the surface of the film. The resistivity of the films was estimated from the linear I-V plots. It was found that the smallest resistivity was obtained using silver contacts, while the largest resistivity was obtained by using indium contacts. This is because silver diffuses in the film and participates in doping, while aluminum and indium cause compensation effects when they diffuse in the film. The best linear fit parameters are those of films with aluminum contacts, and the worst ones are those of films with indium contacts. Annealing was found to improve the electrical properties of the films, especially those deposited at a low substrate temperature. This is because it is expected to encourage crystal growth and to reduce the contact potential which leads to the formation of an alloy. Annealed films are more stable than un-annealed ones.
Ikhmayies, Shadia J.; Ahmad-Bitar, Riyad N.
Surface photovoltage characterization of sol-gel derived Bi 4Ti 3O 12 ferroelectric thin film on F-doped SnO 2 conducting glass
The surface photovoltage response was investigated in partly c-axis oriented Bi 4Ti 3O 12 thin film deposited on fluorine-doped tin oxide conductive glass substrate by a sol-gel technology. The maximum SPV of BiT film reaches 1.8 mV under the dc bias voltage (+1 V) and is three times larger than that under the zero bias. It is also found that the SPV response intensity increases with the increasing positive field, and the intensity of the SPV signal becomes weak with a reverse response when the negative field increases. It is suggested that the SPV is strongly related to the ferroelectric polarization.
Wang, W. C.; Zheng, H. W.; Liu, X. Y.; Liu, X. S.; Gu, Y. Z.; Zhang, H. R.; Zhang, W. F.
Hierarchical growth of SnO2 nanostructured films on FTO substrates: structural defects induced by Sn(ii) self-doping and their effects on optical and photoelectrochemical properties
Direct hydrothermal growth of Sn(ii)-doped SnO2 films on fluorine-doped tin oxide (FTO) substrates results in the formation of upstanding SnO2 nanosheet arrays covered by hierarchical SnO2 nanoflowers. The n-type semiconductor films show extended photoresponse in the visible spectrum arising from the coexistence of Sn(ii) dopant ions and oxygen vacancies in these hierarchical SnO2 nanostructures, which leads to a narrowed bandgap. Photoluminescence spectroscopy revealed that the emission in the UV, blue and red spectral ranges is related to the evolution of Sn(ii) dopants and oxygen vacancies with annealing temperature, whereas oxygen vacancies are mostly responsible for visible emission. The Sn(ii)-doped SnO2 films show higher photocurrent when sensitized with narrow bandgap CdS nanoparticles, serving as efficient electron acceptors.Direct hydrothermal growth of Sn(ii)-doped SnO2 films on fluorine-doped tin oxide (FTO) substrates results in the formation of upstanding SnO2 nanosheet arrays covered by hierarchical SnO2 nanoflowers. The n-type semiconductor films show extended photoresponse in the visible spectrum arising from the coexistence of Sn(ii) dopant ions and oxygen vacancies in these hierarchical SnO2 nanostructures, which leads to a narrowed bandgap. Photoluminescence spectroscopy revealed that the emission in the UV, blue and red spectral ranges is related to the evolution of Sn(ii) dopants and oxygen vacancies with annealing temperature, whereas oxygen vacancies are mostly responsible for visible emission. The Sn(ii)-doped SnO2 films show higher photocurrent when sensitized with narrow bandgap CdS nanoparticles, serving as efficient electron acceptors. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr00672k
Wang, Hongkang; Kalytchuk, Sergii; Yang, Haihua; He, Lifang; Hu, Chenyan; Teoh, Wey Yang; Rogach, Andrey L.
Effect of substrate temperature and deposition rate on the morphology and optical properties of Ti films
Titanium films are deposited on transparent fluorine-doped tin oxide (FTO) glass substrates by DC magnetron sputtering process. Influences imposed by sputtering rate and substrate temperature on surface morphology and optical properties of the deposited Ti films are investigated. We observed that all the sputtered films exhibit uniform and compact surface morphology without peeling and cracking. Morphology of the films is studied using atomic force microscopy (AFM) and X-ray diffraction (XRD). The optical properties of the films are investigated using UV-vis spectroscopy. The morphological studies indicate that by increasing the substrate temperature from room temperature to 250 �C and/or decreasing sputtering rate from 660 �/min to 540 �/min the surface roughness decreased from 73.4 to 31.0 nm and the grain size increases from 50.76 nm to 163.93 nm. An important effect of the root mean square (RMS) surface roughness and grain size is modification of the films optical properties. In fact, an enhancement of refractive index n for the Ti films deposited at high substrate temperature and/or high deposition rate is observed, that is attributed to reduction of RMS roughness. This effect is attributed to increment of fractional volume which leads to an increase in density of deposited film. Thus, by controlling the sputtering conditions one can reach to the desired morphological and optical properties.
Einollahzadeh-Samadi, M.; Dariani, R. S.
Preparation of n-type semiconductor SnO2 thin films
We studied fluorine-doped tin oxide on a glass substrate at 350�C using an ultrasonic spray technique. Tin (II) chloride dehydrate, ammonium fluoride dehydrate, ethanol and NaOH were used as the starting material, dopant source, solvent and stabilizer, respectively. The SnO2 : F thin films were deposited at 350�C and a pending time of 60 and 90 s. The as-grown films exhibit a hexagonal wurtzite structure and have (101) orientation. The G = 31.82 nm value of the grain size is attained from SnO2 : F film grown at 90 s, and the transmittance is greater than 80% in the visible region. The optical gap energy is found to measure 4.05 eV for the film prepared at 90 s, and the increase in the electrical conductivity of the film with the temperature of the sample is up to a maximum value of 265.58 (?�cm)-1, with the maximum activation energy value of the films being found to measure 22.85 meV, indicating that the films exhibit an n-type semiconducting nature.
An all low-temperature fabrication of macroporous, electrochemically addressable anatase thin films.
Macroporous TiO? (anatase) thin films are fabricated by an all low-temperature process in which substrates are dip-coated in suspensions of mixed anatase nanoparticles and polystyrene beads, and the templating agents are removed by ultraviolet (UV) irradiation at a temperature below 50 �C. Scanning electron microscopy (SEM) and Raman spectroscopy show that the templating polymer beads are removed by UV irradiation combined with the photocatalytic activity of TiO?. X-Ray diffraction reveals that nanoparticle growth is negligible in UV irradiated films, while nanoparticle size increases by almost 10 times in calcined films that are prepared for comparison. The macroporous films are prepared on FTO-(fluorine-doped tin oxide) coated glass and ITO (indium tin oxide) coated flexible plastics and thereby used as working electrodes. In both cases, the films are electrochemically addressable, and cyclic voltammetry is consistent with the response of bulk TiO? for calcined films and of nanoscale-TiO? for UV-irradiated films. PMID:24644269
Schr�der, Michael; Sallard, S�bastien; B�hm, Matthias; Einert, Marcus; Suchomski, Christian; Smarsly, Bernd M; Mutisya, Stephen; Bertino, Massimo F
Effect of annealing on properties of electrochemically deposited CdTe thin films
Thin films of CdTe have been deposited onto stainless steel and fluorine-doped tin oxide (FTO)-coated glass substrates from aqueous acidic bath using electrodeposition technique. The different preparative parameters, such as deposition time, bath temperature and pH of the bath have been optimized by photoelectrochemical (PEC) technique to get good quality photosensitive material. The deposited films are annealed at different temperature in presence of air. Annealing temperature is also optimized by PEC technique. The film annealed at 200 �C showed maximum photosensitivity. Different techniques have been used to characterize as deposited and also as annealed (at 200 �C) CdTe thin film. The X-ray diffraction (XRD) analysis showed the polycrystalline nature, and a significant increase in the XRD peak intensities is observed for the CdTe films after annealing. Optical absorption shows the presence of direct transition with band gap energy 1.64 eV and after annealing it decreases to 1.50 eV. Energy dispersive analysis by X-ray (EDAX) study for the as-deposited and annealed films showed nearly stoichiometric compound formation. Scanning electron microscopy (SEM) reveals that spherically shaped grains are more uniformly distributed over the surface of the substrate for the CdTe film.
Kokate, A. V.; Asabe, M. R.; Hankare, P. P.; Chougule, B. K.
Visible light photoelectrochemical properties of ?-Bi2O3 nanoporous films: A study of the dependence on thermal treatment and film thickness
Bi2O3 thin films were successfully prepared on fluorine doped SnO2 substrate by the sol-gel route. The effects of annealing temperature on the film structure and photoelectrochemical (PEC) performance were also discussed. Bi2O3 thin films were characterized by conventional techniques. X-ray diffraction (XRD) results show the 450 �C annealed film exhibits ?-phase structure with the best crystallinity. Scanning electron microscope (SEM) analysis indicates that the surface morphology varies with changing the annealing temperature. The film surface becomes nanoporous at high annealing temperature. Atomic force microscope (AFM) result indicates that the grains on the surface still exhibit close-packed growth in the nanoscale, even though there are many holes in the film surface. The photoelectrochemical performance was evaluated by incident photon-to-current conversion efficiency (IPCE). The IPCE reaches 10.5% at 400 nm (25.5% at 350 nm) without any additional potential vs. Ag/AgCl in 1 M NaOH solution.
Yang, Xin; Lian, Xiaojuan; Liu, Shangjun; Jiang, Chunping; Tian, Jing; Wang, Gang; Chen, Jinwei; Wang, Ruilin
Fluorine compounds for doping conductive oxide thin films
Methods of forming a conductive fluorine-doped metal oxide layer on a substrate by chemical vapor deposition are described. The methods may include heating the substrate in a processing chamber, and introducing a metal-containing precursor and a fluorine-containing precursor to the processing chamber. The methods may also include adding an oxygen-containing precursor to the processing chamber. The precursors are reacted to deposit the fluorine-doped metal oxide layer on the substrate. Methods may also include forming the conductive fluorine-doped metal oxide layer by plasma-assisted chemical vapor deposition. These methods may include providing the substrate in a processing chamber, and introducing a metal-containing precursor, and a fluorine-containing precursor to the processing chamber. A plasma may be formed that includes species from the metal-containing precursor and the fluorine-containing precursor. The species may react to deposit the fluorine-doped metal oxide layer on the substrate.
Gessert, Tim; Li, Xiaonan; Barnes, Teresa M; Torres, Jr., Robert; Wyse, Carrie L
Comparison of Electrochemical Luminescence Characteristics of Titanium Dioxide Films Prepared by Sputtering and Sol--Gel Combustion Methods
Titanium dioxide (TiO2) films were deposited on fluorine-doped tin-oxide (FTO) glass by sputtering and sol--gel combustion (SGC) coating methods and investigated with respect to their electrochemical luminescence (ECL) performance. The sputtered TiO2 films were denser than the SGC-deposited films, while the SGC films were found to be superior in porosity to the sputtered films. The charge transfer resistance (R2) of the SGC (450 �C) TiO2-based cell was found to be lower than those of the sputtered TiO2-based cells. The SGC (450 �C) cell emitted a more intense ECL than the sputter (450 �C) cells. The threshold voltage at which the emission starts was 3.0 V for the SGC (450 �C) cell, which was lower than that (3.5 V) for the sputter (450 �C) cell. The efficiencies were 0.04 lm/W for the sputter (450 �C) cell (R2 = 22.3 ?, porosity= 27.2%) and 0.085 lm/W for the SGC (450 �C) cell (R2 = 12.8 ?, porosity= 65.8%). The SGC-deposited TiO2 films were found to be superior in ECL efficiency to the sputtered TiO2 films.
Park, Hee-Dae; Sung, Youl-Moon; Park, Min-Woo; Song, Jae-Eun
Growth and characterization of pulse electrodeposited CuAlSe2 thin films
In the present work we have grown CuAlSe2 thin films on the fluorine doped tin oxide glass substrates by using Pulse electrodeposition technique. Thin films of CuAlSe2 were co-deposited from an aqueous solution containing CuCl2, AlCl3 and SeO2 adjusted to pH=1.60. Ethylenediamine-di-hydrochloride was used as a complexing agent and films were deposited at the constant deposition potential of -650 mV using pulses of frequency 50 Hz.CuAlSe2 thin films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Energy dispersive analysis of X-rays (EDAX) which indicate the good and reliable quality of the films. An interesting results of this work is that complexing agent plays an important role in reducing the grain size, thus all deposits were found to be in the range of 10-20 nm.
Singh, Joginder; Prasher, Dixit; Nigam, Kamlesh; Rajaram, P.
Rheology of the gelation of fluorine-doped silica sols
Dynamic oscillatory shear measurements are used to probe the gelation kinetics of aqueous sols composed of either particulate silica or silicon alkoxide solutions. Unlike steady shear measurements, these dynamic tests do not alter the structure and kinetics of the sol-gel process. The dynamic storage moduli of both systems show sharp transitions at the onset of gelation. However, the gelation kinetics
Multicoloured electrochromic thin films of NiO/PANI
NiO/polyaniline (PANI) thin films have been prepared by a two-step process. NiO thin films were electrodeposited from an aqueous solution of NiCl2 � 6H2O at pH 7.5 on fluorine-doped tin oxide coated glass substrates and a layer of PANI was formed on NiO thin films by chemical bath deposition. The films were characterized for their structural, optical, morphological and electrochromic properties. X-ray diffraction and Fourier-transform infrared spectroscopy indicated the formation of NiO and PANI, in which NiO is of cubic structure. Scanning electron micrographs represent porous granular NiO, which get uniformly carpeted with PANI, leading to a matty morphology of NiO/PANI samples. The electrochromic performance of NiO/PANI films has been studied using cyclic voltammetry and chronoamperometry over the -1.2 to +2.2 V (versus saturated calomel electrode (SCE)) potential window in 1M LiClO4 + propylene carbonate. The NiO/PANI films exhibit electrochromism with colour that changes from pale yellow (leucoemeraldine base at -0.7 V versus SCE) to dark green (emeraldine salt at 0.4 V versus SCE) to purple (pernigraniline at 0.8 V versus SCE) in the reduced states and dark blue (nigraniline at 0.5 V versus SCE) to dark green (emeraldine salt at 0.1 V versus SCE) to light green (photoemeraldine at -0.3 V versus SCE) in its oxidized states. These colours, though akin to pure PANI, have higher contrast, high speed of operation and high stability, owing to the properties of NiO. The colouration efficiency of the NiO/PANI film was estimated to be 85 cm2 C-1.
Sonavane, A. C.; Inamdar, A. I.; Deshmukh, H. P.; Patil, P. S.
On the influence of DC electric fields on the aerosol assisted chemical vapor deposition growth of photoactive titanium dioxide thin films.
Titanium dioxide thin films were deposited on fluorine doped tin oxide glass substrate from the electric field assisted aerosol chemical vapor deposition (EACVD) reaction of titanium isopropoxide (TTIP, Ti(OC3H7)4) in toluene on glass substrates at a temperature of 450 �C. DC electric fields were generated by applying a potential difference between the electrodes of the transparent coated oxide coated glass substrates during the deposition. The deposited films were characterized using scanning electron microscopy, X-ray diffraction, atomic force microscopy, Raman spectroscopy, and UV-vis spectroscopy. The photoactivity and hydrophilicity of the deposited films were also analyzed using a dye-ink test and water-contact angle measurements. The characterization work revealed that the incorporation of DC electric fields produced significant reproducible changes in the film microstructure, preferred crystallographic orientation, roughness, and film thickness. Photocatalytic activity was calculated from the half-time (t1/2) or time taken to degrade 50% of the initial resazurin dye concentration. A large improvement in photocatalytic activity was observed for films deposited using an electric field with a strong orientation in the (004) direction (t1/2 17 min) as compared to a film deposited with no electric field (t1/2 40 min). PMID:24160408
Romero, Luz; Binions, Russell
Luminescence and electrical properties of solution-processed ZnO thin films by adding fluorides and annealing atmosphere
Highlights: {yields} Systematic study of the fluorides doped solution-processed ZnO thin films via the luminescence and electrical behaviors. {yields} Defect-related visible emission bands are affected by annealing ambient and fluoride addition. {yields} Adding lithium fluoride followed by annealing in oxygen ambient leads to a controlled defect density with proper TFT performance. -- Abstract: To develop an efficient channel layer for thin film transistors (TFTs), understanding the defect-related luminescence and electrical property is crucial for solution-processed ZnO thin films. Film growth with the fluorides addition, especially using LiF, followed by the oxygen ambient post-annealing leads to decreased defect-related emission as well as enhanced switching property. The saturation mobility and current on/off ratio are 0.31 cm{sup 2} V{sup -1} s{sup -1} and 1.04 x 10{sup 3}. Consequently, we can visualize an optimized process condition and characterization method for solution-processed TFT based on the fluorine-doped ZnO film channel layer by considering the overall emission behavior.
Choi, Sungho, E-mail: firstname.lastname@example.com [Advanced Materials Division, Korea Research Institute of Chemical Technology, Yuseong, Daejeon 305-600 (Korea, Republic of)] [Advanced Materials Division, Korea Research Institute of Chemical Technology, Yuseong, Daejeon 305-600 (Korea, Republic of); Park, Byung-Yoon [Chemical and Electronic Materials Division, LG Electronics, Hyangjeong-dong, Heungdeok-gu, Cheongju (Korea, Republic of)] [Chemical and Electronic Materials Division, LG Electronics, Hyangjeong-dong, Heungdeok-gu, Cheongju (Korea, Republic of); Jung, Ha-Kyun [Advanced Materials Division, Korea Research Institute of Chemical Technology, Yuseong, Daejeon 305-600 (Korea, Republic of)] [Advanced Materials Division, Korea Research Institute of Chemical Technology, Yuseong, Daejeon 305-600 (Korea, Republic of)
Photovoltaic characteristics and dye regeneration kinetics in D149-sensitized ZnO with varied dye loading and film thickness.
Porous ZnO electrodes on fluorine-doped tin oxide (FTO) were prepared by electrochemical deposition from an O(2)-saturated ZnCl(2) solution in the presence of eosin Y as a structure directing agent (SDA). Sensitization was reached by desorption of the SDA and subsequent adsorption of the indoline dye D149. The influence of film thickness and dye concentration in the films on their photovoltaic characteristics, recombination, and dye regeneration kinetics was investigated. The recombination kinetics was analyzed by time-resolved photovoltage measurements. The dye regeneration by iodide ions in the electrolyte was investigated using scanning electrochemical microscopy (SECM) feedback mode approach curves. Analysis of a SECM kinetic model shows strongly different effective D149 regeneration rate constants k'(ox) for D149-ZnO electrodes of systematically varied film thickness and dye loading. It was found that the short-circuit current density J(sc) and k'(ox) correlated directly with the adsorbed dye concentration. k'(ox) was found to be independent of the dye loading but correlated strongly with the dye concentration in the film or inversely with the film thickness. Furthermore, we discussed the perspective of correlating macroscopic cell characteristics with SECM kinetics data. PMID:22510720
Tefashe, Ushula Mengesha; Rudolph, Melanie; Miura, Hidetoshi; Schlettwein, Derck; Wittstock, Gunther
Deposition of F-doped ZnO transparent thin films using ZnF2-doped ZnO target under different sputtering substrate temperatures.
Highly transparent and conducting fluorine-doped ZnO (FZO) thin films were deposited onto glass substrates by radio-frequency (RF) magnetron sputtering, using 1.5 wt% zinc fluoride (ZnF2)-doped ZnO as sputtering target. Structural, electrical, and optical properties of the FZO thin films were investigated as a function of substrate temperature ranging from room temperature (RT) to 300�C. The cross-sectional scanning electron microscopy (SEM) observation and X-ray diffraction analyses showed that the FZO thin films were of polycrystalline nature with a preferential growth along (002) plane perpendicular to the surface of the glass substrate. Secondary ion mass spectrometry (SIMS) analyses of the FZO thin films showed that there was incorporation of F atoms in the FZO thin films, even if the substrate temperature was 300�C. Finally, the effect of substrate temperature on the transmittance ratio, optical energy gap, Hall mobility, carrier concentration, and resistivity of the FZO thin films was also investigated. PMID:24572004
Wang, Fang-Hsing; Yang, Cheng-Fu; Lee, Yen-Hsien
Layer-by-layer self-assembled mesoporous PEDOT-PSS and carbon black hybrid films for platinum free dye-sensitized-solar-cell counter electrodes
A thin film of poly(3,4-ethylenedioxythiophene)-poly(4-styrenesulfonic acid) (PEDOT-PSS), which is an alternative cathodic catalyst for Pt in dye-sensitized solar cells, was prepared using the layer-by-layer self-assembly method (LbL). The film is highly adhesive to the substrate and has a controllable thickness. Therefore, the PEDOT-PSS film prepared using LbL is expected have high performance and durability as a counter electrode. Moreover, when carbon black was added to the PEDOT-PSS solution, highly mesoporous PEDOT-PSS and carbon black hybrid films were obtained. These films showed high cathodic activity. In this study, we investigated the change in morphology in the obtained film with increasing carbon black content, and the influence of the porosity and thickness on the performance of the cells. In this study, a Pt-free counter electrode with performance similar to that of Pt-based counter electrodes was successfully fabricated. The achieved efficiency of 4.71% was only a factor of 8% lower than that of the cell using conventional thermally deposited Pt on fluorine-doped tin oxide glass counter electrodes.
Kitamura, Koji; Shiratori, Seimei
Improved Energy Conversion Efficiency of TiO2 Thin Films Modified with Ta2O5 in Dye-Sensitized Solar Cells
Tantalum-doped TiO2 thin films [(TiO2)1-x(Ta2O5)x, x=0{--}0.8%] were prepared on fluorine-doped tin oxide (FTO)-coated substrates by sol--gel technology for uses in dye-sensitized solar cells (DSSCs). The effects of Ta content on the growth and properties of the TiO2 thin films were investigated. The crystallization and microstructures of the thin films were examined by X-ray diffraction, scanning electron microscopy, and Brunauer--Emmett--Teller analyses. The performance of DSSCs based on Ta-doped TiO2 thin films was also studied. From the obtained results, the increases in Jsc and Voc may be due to the increased electron concentration of TiO2 thin film and the flat-band potential of the TiO2 shifted by tantalum doping, respectively. The optimum properties of DSSCs of Voc=0.68 V, Jsc=7.84 mA/cm2, FF=45.1%, and ?=2.4% were obtained using the Ta-doped TiO2 thin film with x=0.5%.
Kao, Ming-Cheng; Chen, Hone-Zern; Young, San-Lin
Synthesis and characterization of Cd{sub 0.7}Pb{sub 0.3}Se thin films for photoelectrochemical solar cell
Optimum composition Cd{sub 0.7}Pb{sub 0.3}Se thin films have been deposited using the chemical bath containing cadmium sulfate octahydrate, lead nitrate, tartaric acid, potassium hydroxide, ammonia, and sodium selenosulfate onto fluorine-doped tin oxide glass substrate. The various deposition parameters such as composition of reactive bath, pH of the solution, deposition temperature, deposition time, speed of rotation, etc. have been optimized for obtaining good quality film. X-ray diffraction studies revealed the polycrystalline nature of sample with the solid solution of lead (II) ions in CdSe host lattice, having a hexagonal phase structure. Scanning electron micrograph suggested that the grains were non-uniformly distributed over the substrate surface. Film composition was determined by atomic absorption spectroscopy as well as energy dispersive X-ray atomic spectroscopy. Optical absorption data showed the presence of direct transition with energy band gap 1.80 eV for the deposited thin films. The dark specific conductance of Cd{sub 0.7}Pb{sub 0.3}Se thin films was found to the order of 10{sup -6} ({omega} cm){sup -1} having n-type semiconducting nature. Photoelectrochemical characterization was carried out using sulfide/polysulfide electrolyte with 1.401% efficiency. (author)
Delekar, S.D.; Patil, M.K. [Department of Chemistry, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad, Sub-center Osmanabad 413 501, Maharashtra (India); Jadhav, B.V.; Sanadi, K.R.; Hankare, P.P. [Solid State Research Laboratory, Department of Chemistry, Shivaji University, Kolhapur 416 004, Maharashtra (India)
Growth of nanocrystalline TiO2 films by pulsed-laser-induced liquid-deposition method and preliminary applications for dye-sensitized solar cells
A novel technique, the pulsed-laser-induced liquid-deposition (PLLD) method, has been employed to grow nanocrystalline TiO2 films on fluorine-doped tin-oxide-coated (FTO) glass substrates at room temperature. The PLLD method was implemented by directing a pulsed laser into a liquid precursor and depositing the photosynthesized nanocrystalline TiO2 on an FTO glass substrate immersed in the liquid precursor. The as-grown nanocrystalline TiO2 films were found to have a rutile crystal structure and consist of a number of flower-like TiO2 crystal units arrayed together on the FTO glass substrate. Each of the flower-like TiO2 crystal units was composed of many nanostructured TiO2 whiskers, and their building blocks were found to be bundles of TiO2 nanorods with diameter of about 5 nm. The growth of these TiO2 nanorods is highly anisotropic, with the preferential growth direction along [001]. As-grown nanocrystalline TiO2 films were annealed at 450�C in air for 30 min for the applications of dye-sensitized solar cells, and the nanostructured characteristics with good porosity were preserved after annealing. A preliminary dye-sensitized solar cell was built based on the annealed nanocrystalline TiO2 film. The results suggest that the PLLD method is a promising technique for growing nanocrystalline TiO2 films for photovoltaic applications.
Wang, Guo-Bing; Fu, Min-Gong; Lu, Bin; Du, Guo-Ping; Li, Li; Qin, Xiao-Mei; Shi, Wang-Zhou
Preparation and characterization of indium doped CdS{sub 0.2}Se{sub 0.8} thin films by spray pyrolysis
The CdS{sub 0.2}Se{sub 0.8} and indium doped CdS{sub 0.2}Se{sub 0.8} thin films have been deposited onto the amorphous glass and fluorine doped tin oxide coated glass substrates by spray pyrolysis. The doping concentration of indium has been optimized by photoelectrochemical characterization technique. The structural, surface morphological, optical and electrical properties of CdS{sub 0.2}Se{sub 0.8} and indium doped CdS{sub 0.2}Se{sub 0.8} thin films have been studied. X-ray diffraction studies reveal that the films are polycrystalline in nature with hexagonal crystal structure. Scanning electron microscopy studies reveal that the grains are uniform with uneven spherically shaped, distributed over the entire substrate surface. The complete surface morphology has been changed after doping. In optical studies, the transition of the deposited films is found to be direct allowed with optical energy gaps decreasing from 1.91 to 1.67 eV with indium doping. Semiconducting behavior has been observed from resistivity measurements. The thermoelectric power measurements reveal that the films exhibit n-type conductivity.
Yadav, A.A., E-mail: email@example.com [Thin Film Physics Laboratory, Department of Physics, Electronics and Photonics, Rajarshi Shahu Mahavidyalaya, Latur 413512, Maharashtra (India); Masumdar, E.U. [Thin Film Physics Laboratory, Department of Physics, Electronics and Photonics, Rajarshi Shahu Mahavidyalaya, Latur 413512, Maharashtra (India)] [Thin Film Physics Laboratory, Department of Physics, Electronics and Photonics, Rajarshi Shahu Mahavidyalaya, Latur 413512, Maharashtra (India)
Langmuir-blodgett films of self-assembled (alkylether-derivatized zn phthalocyanine)-(c60 imidazole adduct) dyad with controlled intermolecular distance for photoelectrochemical studies.
A multilayer Langmuir-Blodgett (LB) film of the self-assembled electron donor-acceptor dyad of Zn phthalocyanine, appended with four long-chain aliphatic ether peripheral substituents, and an imidazole adduct of C60 was prepared and applied as a photoactive material in a photoelectrochemical cell. Changes in the simultaneously recorded surface pressure and surface potential vs area per molecule compression isotherms for Langmuir films of the dyad and, separately, of its components helped to identify phase transitions and mutual interactions of molecules in films. The Brewster angle microscopy (BAM) imaging of the Langmuir films showed circular condensed phase domains of the dyad molecules. The determined area per molecule was lower than that estimated for the dyad and its components, separately. The multilayer LB films of the dyad were transferred onto hydrophobized fluorine-doped tin oxide-coated (FTO) glass slides under different conditions. The presence of both components in the dyad LB films was confirmed with the UV-vis spectroscopy measurements. For the LB films transferred at different surface pressures, the PM-IRRAS measurements revealed that the phthalocyanine macrocycle planes and ether moieties in films were tilted with respect to the FTO surface. The AFM imaging of the LB films indicated formation of relatively uniform dyad LB films. Then, the femtosecond transient absorption spectral studies evidenced photoinduced electron transfer in the LB film. The obtained transient signals corresponding to both Zn(TPPE)(�+) and C60im(�-) confirmed the occurrence of intramolecular electron transfer. The determined rate constants of charge separation, kcs = 2.6 � 10(11) s(-1), and charge recombination, kcr = 9.7 � 10(9) s(-1), indicated quite efficient electron transfer within the film. In the photoelectrochemical studies, either photoanodic or photocathodic current was generated depending on the applied bias potential when the dyad LB film-coated FTO was used as the working electrode and ascorbic acid or methylviologen, respectively, as the charge mediator in an aqueous solution. PMID:24785360
Obraztsov, Ievgen; Noworyta, Krzysztof; Hart, Aaron; Gobeze, Habtom B; Kc, Chandra B; Kutner, Wlodzimierz; D'Souza, Francis
Comparative study of ITO and FTO thin films grown by spray pyrolysis
Tin doped indium oxide (ITO) and fluorine doped tin oxide (FTO) thin films have been prepared by one step spray pyrolysis. Both film types grown at 400 deg. C present a single phase, ITO has cubic structure and preferred orientation (4 0 0) while FTO exhibits a tetragonal structure. Scanning electron micrographs showed homogeneous surfaces with average grain size around 257 and 190 nm for ITO and FTO respectively. The optical properties have been studied in several ITO and FTO samples by transmittance and reflectance measurements. The transmittance in the visible zone is higher in ITO than in FTO layers with a comparable thickness, while the reflectance in the infrared zone is higher in FTO in comparison with ITO. The best electrical resistivity values, deduced from optical measurements, were 8 x 10{sup -4} and 6 x 10{sup -4} {Omega} cm for ITO (6% of Sn) and FTO (2.5% of F) respectively. The figure of merit reached a maximum value of 2.15 x 10{sup -3} {Omega}{sup -1} for ITO higher than 0.55 x 10{sup -3} {Omega}{sup -1} for FTO.
Ait Aouaj, M. [Laboratory of Materials Physics, University of Mohammed V-Agdal, Rabat (Morocco); Diaz, R. [Departamento de Fisica Aplicada C-XII, Universidad Autonoma de Madrid, Madrid (Spain); Belayachi, A. [Laboratory of Materials Physics, University of Mohammed V-Agdal, Rabat (Morocco); Rueda, F. [Departamento de Fisica Aplicada C-XII, Universidad Autonoma de Madrid, Madrid (Spain); Abd-Lefdil, M., E-mail: email@example.com [Laboratory of Materials Physics, University of Mohammed V-Agdal, Rabat (Morocco)
Formation of an electron hole doped film in the ?-Fe2O3 photoanode upon electrochemical oxidation.
Solar hydrogen generation by water splitting in photoelectrochemical cells (PEC) is an appealing technology for a future hydrogen economy. Hematite is a prospective photoanode material in this respect because of its visible light conjugated band gap, its corrosion stability, its environmentally benign nature and its low cost. Its bulk and surface electronic structure has been under scrutiny for many decades and is considered critical for improvement of efficiency. In the present study, hematite films of nominally 500 nm thickness were obtained by dip-coating on fluorine doped tin oxide (FTO) glass slides and then anodised in 1 molar KOH at 500, 600, and 700 mV for 1, 10, 120 and 1440 minutes under dark conditions. X-ray photoelectron spectra recorded at the Fe 3p resonant absorption threshold show that the e(g) transition before the Fermi energy, which is well developed in the pristine hematite film, becomes depleted upon anodisation. The spectral weight of the e(g) peak decreases with the square-root of the anodisation time, pointing to a diffusion controlled process. The speed of this process increases with the anodisation potential, pointing to Arrhenius behaviour. Concomitantly, the weakly developed t(2g) peak intensity becomes enhanced in the same manner. This suggests that the surface of the photoanode contains Fe(2+) species which become oxidized toward Fe(3+) during anodisation. The kinetic behaviour derived from the experimental data suggests that the anodisation forms an electron hole doped film on and below the hematite surface. PMID:23165453
Gajda-Schrantz, Krisztina; Tymen, Simon; Boudoire, Florent; Toth, Rita; Bora, Debajeet K; Calvet, Wolfram; Gr�tzel, Michael; Constable, Edwin C; Braun, Artur
TiO2 paste formulation for crack-free mesoporous nanocrystalline film of dye-sensitized solar cells.
Using a doctor-blade method, a highly viscous titanium dioxide (TiO2) paste was deposited on a glass substrate coated with fluorine doped tin oxide (FTO). The paste was mainly composed of commercially available TiO2 nanoparticles (P25) and hydroxypropyl cellulose (HPC) as organic filler. Varying the content of HPC in the TiO2 paste changed the physical properties of the mesoporous TiO2 layer, particularly its porosity and surface area. From the quantification of dyes on Ti2, layer and the electrochemical impedance spectroscopy (EIS) study of the dye-sensitized solar cells (DSSCs), the surface area of the TiO2 film was found to have decreased. This came with the increase of HPC content while the porosity of the film increased, consistent with the concurrent decrease of short-circuit current density (Jsc) and efficiency (eta). The increased porosity greatly affected the electron transport through the TiO2 film by decreasing the coordination number of the TiO2 particles resulting to a decrease of the electron diffusion coefficient. PMID:22966572
Sarker, Subrata; Nath, Narayan Chandra Deb; Rahman, M Mahbubur; Lim, Sung-Su; Ahammad, A J Saleh; Choi, Won-Youl; Lee, Jae-Joon
Photovoltaic effect of TiO2 thick films with an ultrathin BiFeO3 as buffer layer
The photovoltaic (PV) effect of a bilayer anatase TiO2/BiFeO3 (BFO) film has been studied. The 20-nm ultrathin BFO layers were deposited on the fluorine-doped tin oxide (FTO) glass substrates by the chemical solution deposition method. An anatase TiO2 layer is deposited subsequently on the BFO surface via a screen-printing technique. It is found that the FTO/TiO2/Au cell exhibits negligible PV effect under solar exposure, while the one after introducing an ultrathin BFO film between TiO2 and FTO leads to a considerable PV effect with an open-circuit voltage of -0.58 V and a photocurrent density of 18.27 �A/cm2. The FTO/BiVO4 (BVO)/TiO2/Au cell was constructed to investigate the underlying mechanism for the observed effect. A negligible PV effect of the FTO/BVO/TiO2/Au cell indicates that the PV effect of the FTO/BFO/TiO2/Au cell arises mainly from a built-in electric field in the BFO film induced by the self-polarization. Our work opens up a new path to utilize TiO2 and may influence the future design of solar cells.
Wu, Fen; Song, Linyu; Guo, Yiping; Jin, Song; Bi, Enbing; Chen, Han; Duan, Huanan; Li, Hua; Liu, Hezhou; Kang, Hongmei
Preparation and characterization of spray deposited n-type WO{sub 3} thin films for electrochromic devices
The n-type tungsten oxide (WO{sub 3}) polycrystalline thin films have been prepared at an optimized substrate temperature of 250 deg. C by spray pyrolysis technique. Precursor solution of ammonium tungstate ((NH{sub 4}){sub 2}WO{sub 4}) was sprayed onto the well cleaned, pre-heated fluorine doped tin oxide coated (FTO) and glass substrates with a spray rate of 15 ml/min. The structural, surface morphological and optical properties of the as-deposited WO{sub 3} thin films were studied. Mott-Schottky (M-S) studies of WO{sub 3}/FTO electrodes were conducted in Na{sub 2}SO{sub 4} solution to identify their nature and extract semiconductor parameters. The electrochromic properties of the as-deposited and lithiated WO{sub 3}/FTO thin films were analyzed by employing them as working electrodes in three electrode electrochemical cell using an electrolyte containing LiClO{sub 4} in propylene carbonate (PC) solution.
Sivakumar, R.; Moses Ezhil Raj, A.; Subramanian, B.; Jayachandran, M.; Trivedi, D.C.; Sanjeeviraja, C
Evolution of ZnO architecture on a nanoporous TiO2 film by a hydrothermal method and the photoelectrochemical performance
The synthesis of ZnO architecture on a fluorine-doped SnO2 (FTO) conducting glass pre-coated with nanoporous TiO2 film has been achieved by a one-step hydrothermal method at a temperature of 70�C. The effect of the reaction time on the morphology of the ZnO architecture has been investigated, and a possible growth mechanism for the formation of the ZnO architecture is discussed in detail. The morphology and phase structures of the as-obtained composite films have been investigated by field-emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). The results show that the growth time greatly affects the morphology of the obtained ZnO architecture. The photoelectrochemical performances of as-prepared composite films are measured by assembling them into dye sensitized solar cells (DSSCs). The DSSC based on the as-prepared composite film (2 h) has obtained the best power conversion efficiency of 1.845%.
Yinhua, Jiang; Xiaoli, Wu; Wenli, Zhang; Liang, Ni; Yueming, Sun
Charge defects and highly enhanced multiferroic properties in Mn and Cu co-doped BiFeO3 thin films
Pure BiFeO3 (BFO) and Mn, Cu co-doped BiFeO3 (BFMCO) thin films were deposited on fluorine doped tin oxide (FTO) substrates by a chemical solution deposition method. Detailed investigations were made on the effects of Mn and Cu co-doping on the crystal structure, the defect chemistry, multiferroic properties of the BFO thin films. With the co-doping of Mn and Cu, a structural transition from the rhombohedral (R3c:H) to the biphasic structure (R3c:H + P1) is confirmed by XRD, Rietveld refinement and Raman analysis. X-ray photoelectron spectroscopy (XPS) analysis shows that the coexistence of Fe2+/Fe3+ and Mn2+/Mn3+ ions in the co-doping films are demonstrated. Meanwhile, the way of the co-doping at B-sits is conducive to suppress Fe valence state of volatility and to decrease oxygen vacancies and leakage current. It's worth noting that the co-doping can induce the superior ferroelectric properties (a huge remanent polarization, 2Pr ? 220 ?C/cm2 and a relatively low coercive field, 2Ec ? 614 kV/cm). The introduction of Mn2+ and Cu2+ ions optimizes the magnetic properties of BFO thin films by the biphasic structure and the destruction of spin cycloid.
Dong, Guohua; Tan, Guoqiang; Luo, Yangyang; Liu, Wenlong; Xia, Ao; Ren, Huijun
CdS nanoparticles sensitization of Al-doped ZnO nanorod array thin film with hydrogen treatment as an ITO/FTO-free photoanode for solar water splitting
Aluminum-doped zinc oxide (AZO) nanorod array thin film with hydrogen treatment possesses the functions of transparent conducting oxide thin film and 1-D nanostructured semiconductor simultaneously. To enhance the absorption in the visible light region, it is sensitized by cadmium sulfide (CdS) nanoparticles which efficiently increase the absorption around 460 nm. The CdS nanoparticles-sensitized AZO nanorod array thin film with hydrogen treatment exhibits significantly improved photoelectrochemical property. After further heat treatment, a maximum short current density of 5.03 mA cm?2 is obtained under illumination. They not only are much higher than those without CdS nanoparticles sensitization and those without Al-doping and/or hydrogen treatment, but also comparable and even slightly superior to some earlier works for the CdS-sensitized zinc oxide nanorod array thin films with indium tin oxide (ITO) or fluorine-doped tin oxide (FTO) as substrates. This demonstrated successfully that the AZO nanorod array thin film with hydrogen treatment is quite suitable as an ITO/FTO-free photoanode and has great potentials in solar water splitting after sensitization by quantum dots capable of visible light absorption.
Direct measurement of the upper critical field in cuprate superconductors.
In the quest to increase the critical temperature Tc of cuprate superconductors, it is essential to identify the factors that limit the strength of superconductivity. The upper critical field Hc2 is a fundamental measure of that strength, yet there is no agreement on its magnitude and doping dependence in cuprate superconductors. Here we show that the thermal conductivity can be used to directly detect Hc2 in the cuprates YBa2Cu3Oy, YBa2Cu4O8 and Tl2Ba2CuO6+?, allowing us to map out Hc2 across the doping phase diagram. It exhibits two peaks, each located at a critical point where the Fermi surface of YBa2Cu3Oy is known to undergo a transformation. Below the higher critical point, the condensation energy, obtained directly from Hc2, suffers a sudden 20-fold collapse. This reveals that phase competition-associated with Fermi-surface reconstruction and charge-density-wave order-is a key limiting factor in the superconductivity of cuprates. PMID:24518054
Grissonnanche, G; Cyr-Choini�re, O; Lalibert�, F; Ren� de Cotret, S; Juneau-Fecteau, A; Dufour-Beaus�jour, S; Delage, M-�; LeBoeuf, D; Chang, J; Ramshaw, B J; Bonn, D A; Hardy, W N; Liang, R; Adachi, S; Hussey, N E; Vignolle, B; Proust, C; Sutherland, M; Kr�mer, S; Park, J-H; Graf, D; Doiron-Leyraud, N; Taillefer, Louis
Direct measurement of the upper critical field in cuprate superconductors
In the quest to increase the critical temperature Tc of cuprate superconductors, it is essential to identify the factors that limit the strength of superconductivity. The upper critical field Hc2 is a fundamental measure of that strength, yet there is no agreement on its magnitude and doping dependence in cuprate superconductors. Here we show that the thermal conductivity can be used to directly detect Hc2 in the cuprates YBa2Cu3Oy, YBa2Cu4O8 and Tl2Ba2CuO6+?, allowing us to map out Hc2 across the doping phase diagram. It exhibits two peaks, each located at a critical point where the Fermi surface of YBa2Cu3Oy is known to undergo a transformation. Below the higher critical point, the condensation energy, obtained directly from Hc2, suffers a sudden 20-fold collapse. This reveals that phase competition�associated with Fermi-surface reconstruction and charge-density-wave order�is a key limiting factor in the superconductivity of cuprates.
Grissonnanche, G.; Cyr-Choini�re, O.; Lalibert�, F.; Ren� de Cotret, S.; Juneau-Fecteau, A.; Dufour-Beaus�jour, S.; Delage, M.-�.; Leboeuf, D.; Chang, J.; Ramshaw, B. J.; Bonn, D. A.; Hardy, W. N.; Liang, R.; Adachi, S.; Hussey, N. E.; Vignolle, B.; Proust, C.; Sutherland, M.; Kr�mer, S.; Park, J.-H.; Graf, D.; Doiron-Leyraud, N.; Taillefer, Louis
TiO2 Coating for SnO2:F Films Produced by Filtered Cathodic Arc Evaporation for Improved Resistance to H+ Radical Exposure
Titanium dioxide thin films were deposited by filtered cathodic arc evaporation (FCAE) from a Ti target in an oxygen atmosphere onto (a) fluorine-doped tin oxide substrates SnO2:F (FTO) and (b) glass microscope slides. The growth rate calculated from film thickness profilometry measurements was found to be approximately 0.8 nm/s. The films were highly transparent to visible light. x-Ray photoemission spectroscopy analysis of the Ti 2p electron binding- energy shift confirmed the presence of a TiO2 stoichiometric compound. The results for the root-mean-square (RMS) surface roughness of the films deposited onto FTO substrates evaluated by atomic force microscopy suggested nanostructured film surfaces. When exposed to hydrogen plasma, TiO2 films revealed insignificant changes in the optical spectra. The initial sheet resistance of the SnO2:F layer was 14 ?/sq. The deposition of the top TiO2 layer (45 nm thick) over the FTO electrode resulted in an increase of the sheet resistance of 2 ?/sq. In addition, the sheet resistance of the double-layer FTO/TiO2 transparent conductive oxide (TCO) electrode increased by 1 ?/sq as a result of H+ plasma exposure. Regardless of the TiO2 film's low conductivity, a thin protective layer could be coated onto FTO films (presumably 15 nm thick) due to their high transparency, offering high resistance to aggressive H+ plasma conditions. In this paper we show that �50-nm-thick TiO2 coating on FTO films provides sufficient protection against deterioration of transparency and conductivity due to hydrogen radical exposure.
Ristova, M. M.; Gligorova, A.; Nasov, I.; Gracin, D.; Milun, M.; Kostadinova-Boskova, H.; Popeski-Dimovski, R.
Enhancing light trapping properties of thin film solar cells by plasmonic effect of silver nanoparticles.
The preparation of thin film silicon solar cells containing Ag nanoparticles is reported in this article. Ag nanoparticles were deposited on fluorine doped tin oxide coated glass substrates by the evaporation and condensation method. a-Si:H solar cells were deposited on these substrates by cluster type plasma enhanced chemical vapor deposition. We discuss the double textured surface effect with respect to both the surface morphology of the substrate and the plasmonic effect of the Ag nanoparticles. Ag nanoparticles of various sizes from 10 to 100 nm were deposited. The haze values of the Ag embedded samples increased with increasing particle size whereas the optical transmittance decreased at the same conditions. The solar cell with the 30 nm size Ag nanoparticles showed a short circuit current density of 12.97 mA/cm2, which is 0.53 mA/cm2 higher than that of the reference solar cell without Ag nanoparticles, and the highest quantum efficiency for wavelengths from 550 to 800 nm. When 30 nm size nanoparticles were employed, the conversion efficiency of the solar cell was increased from 6.195% to 6.696%. This study reports the application of the scattering effect of Ag nanoparticles for the improvement of the conversion efficiency of amorphous silicon solar cells. PMID:24266153
Jung, Junhee; Ha, Kyungyeon; Cho, Jaehyun; Ahn, Shihyun; Park, Hyeongsik; Hussain, Shahzada Qamar; Choi, Mansoo; Yi, Junsin
Solvothermal preparation of an electrocatalytic metalloporphyrin MOF thin film and its redox hopping charge-transfer mechanism.
A thin film of a metalloporphyrin metal-organic framework consisting of [5,10,15,20-(4-carboxyphenyl)porphyrin]Co(III) (CoTCPP) struts bound by linear trinuclear Co(II)-carboxylate clusters has been prepared solvothermally on conductive fluorine-doped tin oxide substrates. Characterization of this mesoporous thin film material, designated as CoPIZA/FTO, which is equipped with large cavities and access to metal active sites, reveals an electrochemically active material. Cyclic voltammetry displays a reversible peak with E(1/2) at -1.04 V vs ferrocyanide attributed to the (Co(III/II)TCPP)CoPIZA redox couple and a quasi-reversible peak at -1.45 V vs ferrocyanide, which corresponds to the reduction of (Co(II/I)TCPP)CoPIZA. Analysis of the spectroelectrochemical response for the (Co(II/I)TCPP)CoPIZA redox couple revealed non-Nernstian reduction with a nonideality factor of 2 and an E(1/2) of -1.39 V vs ferrocyanide. The film was shown to retain its structural integrity with applied potential, as was demonstrated spectroelectrochemically with maintenance of isosbestic points at 430, 458, and 544 nm corresponding to the (Co(III/II)TCPP)CoPIZA transition and at 390 and 449 nm corresponding to the (Co(II/I)TCPP)CoPIZA transition. The mechanism of charge transport through the film is proposed to be a redox hopping mechanism, which is supported by both cyclic voltammetry and spectroelectrochemistry. A fit of the time-dependent spectroelectrochemical data to a modified Cottrell equation gave an apparent diffusion coefficient of 7.55 (�0.05) � 10(-14) cm(2)/s for ambipolar electron and cation transport throughout the film. Upon reduction of the metalloporphyrin struts to (Co(I)TCPP)CoPIZA, the CoPIZA thin film demonstrated catalytic activity for the reduction of carbon tetrachloride. PMID:24437480
Ahrenholtz, Spencer R; Epley, Charity C; Morris, Amanda J
All-nanoparticle self-assembly ZnO/TiO? heterojunction thin films with remarkably enhanced photoelectrochemical activity.
The multilaminated ZnO/TiO2 heterojunction films were successfully deposited on conductive substrates including fluorine-doped tin oxide (FTO) glass and flexible indium tin oxide coated poly(ethylene terephthalate) via the layer-by-layer (LBL) self assembly method from the oxide colloids without using any polyelectrolytes. The positively charged ZnO nanoparticles and the negatively charged TiO2 nanoparticles were directly used as the components in the consecutive deposition process to prepare the heterojunction thin films by varying the thicknesses. Moreover, the crystal growth of both oxides could be efficiently inhibited by the good connection between ZnO and TiO2 nanoparticles even after calcination at 500 �C, especially for ZnO which was able to keep the crystallite size under 25 nm. The as-prepared films were used as the working electrodes in the three-electrode photoelectrochemical cells. Because the well-contacted nanoscale heterojunctions were formed during the LBL self-assembling process, the ZnO/TiO2 all-nanoparticle films deposited on both substrates showed remarkably enhanced photoelectrochemical properties compared to that of the well-established TiO2 LBL thin films with similar thicknesses. The photocurrent response collected from the ZnO/TiO2 electrode on the FTO glass substrate was about five times higher than that collected from the TiO2 electrode. Owing to the absence of the insulating layer of dried polyelectrolytes, the ZnO/TiO2 all-nanoparticle heterojunction films were expected to be used in the photoelectrochemical device before calcination. PMID:24670479
Yuan, Sujun; Mu, Jiuke; Mao, Ruiyi; Li, Yaogang; Zhang, Qinghong; Wang, Hongzhi
Fabrication of a double layered FTO/AZO film structure having enhanced thermal, electrical and optical properties, as a substitute for ITO films
An ideal transparent conducting oxide (TCO) should possess high optical transparency and electrical conductivity along with good chemical and thermal stabilities while it is subjected to high temperature processes. In the present study, a novel TCO film which possesses good figure of merit (?) (i.e. good optical transparency and electrical conductivity) along with good chemical and thermal stabilities and especially which can acts as a substitute for ITO has been realized. To achieve the combined unique characteristics of ZnO (thermal stability) and SnO2 (chemical stability), a double layered structure which consists of fluorine doped tin oxide (FTO) as the top layer on AZO layer, has been deposited using a simplified spray pyrolysis technique. In order to optimize the thickness proportions of FTO/AZO double layer for obtaining improved quality factors, five sets of samples were fabricated with different thickness proportions (1:5, 1:2, 1:1, 2:1 and 5:1) of AZO and FTO layers. Then, for the better understanding of physical properties of FTO/AZO double layered films, structural, optical and electrical studies were carried out and the results are reported. The minimum electrical resistivity of 9.141 � 10-3 ? cm with 80 % of optical transparency obtained for the FTO/AZO bilayer film having 5:1 thickness proportion, prompts us to conclude that this thickness proportion is suitable to achieve improved quality factor (1.185 � 10-3 (?/?)-1). The quality factor is found to be increased nearly four times after annealing (3.965 � 10-3 (?/?)-1).
Ravichandran, K.; Jabena Begum, N.; Swaminathan, K.; Sakthivel, B.
Pulsing frequency induced change in optical constants and dispersion energy parameters of WO3 films grown by pulsed direct current magnetron sputtering
In this work, we present the pulsing frequency induced change in the structural, optical, vibrational, and luminescence properties of tungsten oxide (WO3) thin films deposited on microscopic glass and fluorine doped tin oxide (SnO2:F) coated glass substrates by pulsed dc magnetron sputtering technique. The WO3 films deposited on SnO2:F substrate belongs to monoclinic phase. The pulsing frequency has a significant influence on the preferred orientation and crystallinity of WO3 film. The maximum optical transmittance of 85% was observed for the film and the slight shift in transmission threshold towards higher wavelength region with increasing pulsing frequency revealed the systematic reduction in optical energy band gap (3.78 to 3.13 eV) of the films. The refractive index (n) of films are found to decrease (1.832 to 1.333 at 550 nm) with increasing pulsing frequency and the average value of extinction coefficient (k) is in the order of 10-3. It was observed that the dispersion data obeyed the single oscillator of the Wemple-Didomenico model, from which the dispersion energy (Ed) parameters, dielectric constants, plasma frequency, oscillator strength, and oscillator energy (Eo) of WO3 films were calculated and reported for the first time due to variation in pulsing frequency during deposition by pulsed dc magnetron sputtering. The Eo is change between 6.30 and 3.88 eV, while the Ed varies from 25.81 to 7.88 eV, with pulsing frequency. The Raman peak observed at 1095 cm-1 attributes the presence of W-O symmetric stretching vibration. The slight shift in photoluminescence band is attributed to the difference in excitons transition. We have made an attempt to discuss and correlate these results with the light of possible mechanisms underlying the phenomena.
Punitha, K.; Sivakumar, R.; Sanjeeviraja, C.
Fast Classification of Meat Spoilage Markers Using Nanostructured ZnO Thin Films and Unsupervised Feature Learning
This paper investigates a rapid and accurate detection system for spoilage in meat. We use unsupervised feature learning techniques (stacked restricted Boltzmann machines and auto-encoders) that consider only the transient response from undoped zinc oxide, manganese-doped zinc oxide, and fluorine-doped zinc oxide in order to classify three categories: the type of thin film that is used, the type of gas, and the approximate ppm-level of the gas. These models mainly offer the advantage that features are learned from data instead of being hand-designed. We compare our results to a feature-based approach using samples with various ppm level of ethanol and trimethylamine (TMA) that are good markers for meat spoilage. The result is that deep networks give a better and faster classification than the feature-based approach, and we thus conclude that the fine-tuning of our deep models are more efficient for this kind of multi-label classification task.
Langkvist, Martin; Coradeschi, Silvia; Loutfi, Amy; Rayappan, John Bosco Balaguru
Enhanced photocatalytic properties of nanoclustered P-doped TiO2 films deposited by advanced atmospheric plasma jet.
A facile preparation of P-doped TiO2 nanoclusters onto fluorine-doped tin oxide (FTO) glass by an advanced atmospheric plasma jet (AAP jet) is reported here. Titanium tetrachloride (TiCl4) and phosphorus trichloride (PCl3) were used as precursors. Radio frequencies were used to generate plasma at fix powder with Argon as carrier gas. Films were deposited at 500 degrees C for 10 minutes. For comparison, as-prepared, annealed and deposited at 500 degrees C samples were studied for chemical/physical properties by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Optical properties were studied by using UV-Vis spectroscopy which indicated a reduction in optical band with P-doping. The rhodamine B (Rh-B) degradation by P-doped TiO2 deposited at 500 degrees C showed enhanced degradation efficiency than that of annealed TiO2. The suggested deposition method appears to be suitable for the synthesis of photocatalyst with proper control over dopants. PMID:23035425
Seo, Hyung-Kee; Elliott, C Michael; Ansari, S G
Large-area SnO{sub 2}: F thin films by offline APCVD
Highlights: {yields} Large-area (1245 mm x 635 mm) FTO thin films were successfully deposited by offline APCVD process. {yields} The as-prepared FTO thin films with sheet resistance 8-11 {Omega}/{open_square} and direct transmittance more than 83% exhibited better than that of the online ones. {yields} The maximum quantum efficiency of the solar cells based on offline FTO substrate was 0.750 at wavelength 540 nm. {yields} The power of the solar modules using the offline FTO as glass substrates was 51.639 W, higher than that of the modules based on the online ones. -- Abstract: In this paper, we reported the successful preparation of fluorine-doped tin oxide (FTO) thin films on large-area glass substrates (1245 mm x 635 mm x 3 mm) by self-designed offline atmospheric pressure chemical vapor deposition (APCVD) process. The FTO thin films were achieved through a combinatorial chemistry approach using tin tetrachloride, water and oxygen as precursors and Freon (F-152, C2H4F2) as dopant. The deposited films were characterized for crystallinity, morphology (roughness) and sheet resistance to aid optimization of materials suitable for solar cells. We got the FTO thin films with sheet resistance 8-11 {Omega}/{open_square} and direct transmittance more than 83%. X-ray diffraction (XRD) characterization suggested that the as-prepared FTO films were composed of multicrystal, with the average crystal size 200-300 nm and good crystallinity. Further more, the field emission scanning electron microscope (FESEM) images showed that the films were produced with good surface morphology (haze). Selected samples were used for manufacturing tandem amorphous silicon (a-Si:H) thin film solar cells and modules by plasma enhanced chemical vapor deposition (PECVD). Compared with commercially available FTO thin films coated by online chemical vapor deposition, our FTO coatings show excellent performance resulting in a high quantum efficiency yield for a-Si:H solar cells and ideal open voltage and short circuit current for a-Si:H solar modules.
Wang, Yan [School of Materials Science and Engineering, Hefei University of Technology, Hefei, Anhui 230009 (China)] [School of Materials Science and Engineering, Hefei University of Technology, Hefei, Anhui 230009 (China); Wu, Yucheng, E-mail: email@example.com [School of Materials Science and Engineering, Hefei University of Technology, Hefei, Anhui 230009 (China)] [School of Materials Science and Engineering, Hefei University of Technology, Hefei, Anhui 230009 (China); Qin, Yongqiang; Zhang, Zhihai [School of Materials Science and Engineering, Hefei University of Technology, Hefei, Anhui 230009 (China)] [School of Materials Science and Engineering, Hefei University of Technology, Hefei, Anhui 230009 (China); Shi, Chengwu [School of Materials Science and Engineering, Hefei University of Technology, Hefei, Anhui 230009 (China) [School of Materials Science and Engineering, Hefei University of Technology, Hefei, Anhui 230009 (China); Reno Energy Saving Technology Co., Ltd., Bengbu, Anhui 233010 (China); Zhang, Qingfeng [Reno Energy Saving Technology Co., Ltd., Bengbu, Anhui 233010 (China) [Reno Energy Saving Technology Co., Ltd., Bengbu, Anhui 233010 (China); Polar Photovoltaics Co., Ltd., Bengbu, Anhui 233030 (China); Li, Changhao [Reno Energy Saving Technology Co., Ltd., Bengbu, Anhui 233010 (China)] [Reno Energy Saving Technology Co., Ltd., Bengbu, Anhui 233010 (China); Xia, Xiaohong; Sun, Stanley [Reno Energy Saving Technology Co., Ltd., Bengbu, Anhui 233010 (China) [Reno Energy Saving Technology Co., Ltd., Bengbu, Anhui 233010 (China); Polar Photovoltaics Co., Ltd., Bengbu, Anhui 233030 (China); Chen, Leon [Polar Photovoltaics Co., Ltd., Bengbu, Anhui 233030 (China)] [Polar Photovoltaics Co., Ltd., Bengbu, Anhui 233030 (China)
Visible light-induced water oxidation on mesoscopic alpha-Fe2O3 films made by ultrasonic spray pyrolysis.
Alpha-Fe(2)O(3) films having a mesoscopic leaflet type structure were produced for the first time by ultrasonic spray pyrolysis (USP) to explore their potential as oxygen-evolving photoanodes. The target of these studies is to use translucent hematite films deposited on conducting fluorine doped tin oxide (FTO) glass as top electrodes in a tandem cell that accomplishes the cleavage of water into hydrogen and oxygen by sunlight. The properties of layers made by USP were compared to those deposited by conventional spray pyrolysis (SP). Although both types of films show similar XRD and UV-visible and Raman spectra, they differ greatly in their morphology. The mesoscopic alpha-Fe(2)O(3) layers produced by USP consist mainly of 100 nm-sized platelets with a thickness of 5-10 nm. These nanosheets are oriented mainly perpendicularly to the FTO support, their flat surface exposing (001) facets. The mesoscopic leaflet structure has the advantage that it allows for efficient harvesting of visible light, while offering at the same time the very short distance required for the photogenerated holes to reach the electrolyte interface before recombining with conduction band electrons. This allows for water oxidation by the valence band holes even though their diffusion length is only a few nanometers. Distances are longer in the particles produced by SP favoring recombination of photoinduced charge carriers. Open-circuit photovoltage measurements indicate a lower surface state density for the nanoplatelets as compared to the round particles. These factors explain the much higher photoactivity of the USP compared to the SP deposited alpha-Fe(2)O(3) layers. Addition of hydrogen peroxide to the alkaline electrolyte further improves the photocurrent-voltage characteristics of films generated by USP indicating the hole transfer from the valence band of the semiconductor oxide to the adsorbed water to be the rate-limiting kinetic step in the oxygen generation reaction. PMID:16853192
Duret, Alexis; Gr�tzel, Michael
Deposition of a thin film of TiOx from a titanium metal target as novel blocking layers at conducting glass/TiO2 interfaces in ionic liquid mesoscopic TiO2 dye-sensitized solar cells.
In dye-sensitized TiO2 solar cells, charge recombination processes at interfaces between fluorine-doped tin oxide (FTO), TiO2, dye, and electrolyte play an important role in limiting the photon-to-electron conversion efficiency. From this point of view, a high work function material such as titanium deposited by sputtering on FTO has been investigated as an effective blocking layer for preventing electron leakage from FTO without influencing electron injection. X-ray photoelectron spectroscopy analysis indicates that different species of Ti (Ti4+, Ti3+, Ti2+, and a small amount of Ti0) exist on FTO. Electrochemical and photoelectrochemical measurements reveal that thin films of titanium species, expressed as TiOx, work as a compact blocking layer between FTO and TiO2 nanocrystaline film, improving Voc and the fill factor, finally giving a better conversion efficiency for dye-sensitized TiO2 solar cells with ionic liquid electrolytes. PMID:17165966
Xia, Jiangbin; Masaki, Naruhiko; Jiang, Kejian; Yanagida, Shozo
Vertically aligned ZnO nanorods on hot filament chemical vapor deposition grown graphene oxide thin film substrate: solar energy conversion.
Vertically aligned zinc oxide (ZnO) nanorods (NRs) were grown by the low-temperature hydrothermal method on graphene oxide (GO) coated FTO substrates, where GO was directly deposited on fluorine doped tin oxide (FTO) substrates using hydrogen (H(2), 65 sccm) and methane (CH(4), 50 sccm) through hot filament chemical vapor deposition (HFCVD) technique. The vertically aligned ZnO NRs were applied as effective photoanode for the fabrication of efficient dye sensitized solar cells (DSSCs). Highly uniform ZnO NRs were grown on GO deposited FTO substrate with the average length of ?2-4 ?m and diameter of ?200-300 nm. The possible mechanism of grown ZnO NRs clearly revealed the significant role of GO on FTO in architecting the aligned growth of ZnO NRs. The grown vertically aligned ZnO NRs possessed a typical wurtzite hexagonal crystal structure. The structural and the optical studies confirmed the formation of partial hydrogen bonding between surface functional groups of GO and ZnO NRs. A solar-to-electricity conversion efficiency of ?2.5% was achieved by DSSC fabricated with ZnO NRs deposited on graphene oxide (GO-ZnO NRs) thin film photoanode. The presence of GO on FTO substrate expressively increased the surface area of GO-ZnO photoanode, which resulted in high dye loading as well as high light harvesting efficiency and thus ensued the increased photocurrent density and the improved performance of DSSCs. PMID:22827848
Ameen, Sadia; Akhtar, M Shaheer; Song, Minwu; Shin, Hyung Shik
Synchronous Electrochromism of Lithium Ion Battery with Chemically Fabricated Transparent Thin Films
Electrochromism synchronous to the charge/discharge of a novel Li ion battery having Li3Fe2(PO4)3 and Li4Ti5O12 thin-film electrodes fabricated by a chemical process, the molecular precursor method, was discovered. A cathode of transparent Li3Fe2(PO4)3 thin film with a thickness of 80 nm was fabricated by heat treating a precursor ethanol solution including a Li(I) complex of nitrilotriacetic acid, an Fe(III) complex of ethylenediaminetetraacetic acid, and (dibutylammonium)2H2P2O7 ? 0.5H2O at 550�C for 10 min in air. An anode of transparent Li4Ti5O12 thin film with a thickness of 90 nm was fabricated by heat treating a precursor ethanol solution including a Li(I) complex of nitrilotriacetic acid, a Ti(IV) complex of the identical organic ligand, and hydrogen peroxide at 550�C for 30 min in air. The precursor films for both electrodes were fabricated with a spin-coating method. The thermal reactions of the novel precursors were examined in detail by means of thermogravimetry and differential thermal analysis in order to examine the components and heat-treatment temperature. The crystal structure and surface morphology of the thin-film electrodes fabricated on glass substrates pre-coated with a fluorine-doped tin oxide film were examined with X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The rechargeable function of the assembled sandwich-type battery using an electrolytic solution containing LiPF6 was measured by the repeated charge and discharge test at a constant current of 10 ?A; a maximum voltage of 3.6 V was recorded. The color changes of the transparent thin-film battery between colorless before charging and a blue-gray color after charging occurred synchronously and repeatedly with the charge/discharge cycles. The intercalation of Li+ ions into the Li4Ti5O12 thin-film anode may be related to the drastic color change and the unprecedented visualization of the electrochemical reaction of a novel Li ion battery.
Nagai, Hiroki; Hara, Hiroki; Enomoto, Mitsuhiro; Mochizuki, Chihiro; Honda, Tohru; Takano, Ichiro; Sato, Mitsunobu
Strategies for stabilization of electrodeposited metal particles in electropolymerized films for H2O oxidation and H+ reduction.
Metal particles were electrodeposited on a variety of conducting substrates, and their electrocatalytic activity toward H2O oxidation to O2 and H(+) reduction to H2 was evaluated. Co, Ni, Cu, Pd, Ag, and Pt were all electrodeposited on fluorine-doped tin oxide (FTO) electrodes. Particularly active were Pd and Pt for H(+) reduction and Co and Ag for H2O oxidation. When cycled reductively in 0.1 M HClO4, FTO electrodes derivatized with Pt and Pd reached current densities for hydrogen evolution of 18.3 and 13.2 mA/cm(2), respectively, at -0.6 V vs normal hydrogen electrode (NHE). FTO electrodes with electrodeposited Co or Ag were cycled oxidatively in H2O buffered to pH 7 with phosphate buffer. Current densities of 10.5 and 8.70 mA/cm(2), respectively, were reached at +1.8 V vs NHE with H2O oxidation onsets at +1.3 and +1.4 V, respectively. The impacts on catalytic stability and performance of electrodeposited metals in/on an electrically conductive polymer support were also investigated. Films of poly-[Fe(vbpy)3](PF6)2 (vbpy is 4-methyl-4'-vinyl-2,2'-bipyridine) were generated on FTO by reductive electropolymerization. Significant improvements to the long-term stability of electrodeposited Ag and Pt particles were observed in the poly-[Fe(vbpy)3](PF6)2 support. Films of poly-[M(vbpy)3](PF6)2 with M = Co(II) or Cu(II) were also prepared and evaluated as electrocatalysts for H2O oxidation. Films containing Co(II) reached current densities of 6.0 mA/cm(2) at +1.8 V vs NHE in H2O. PMID:23806103
Torelli, Daniel A; Harrison, Daniel P; Lapides, Alexander M; Meyer, Thomas J
Solution-based deposition of ceramic thin films for electronic applications
With the requirement of a low-temperature process which is compatible with flexible electronics, solution-based processes for ceramic thin films have received substantial attention in recent years. In this study, two different variations of solution processing were explored. Liquid phase deposition (LPD) was used to prepare for F-doped SiO2 and F-doped SnO2, and hydrothermal processing was used to prepare ZnO thin films consisting of vertically aligned nanorods. F-doped SiO2 thin films were developed from supersaturated hydrofluorosilicic acid (H2SiF6) solution with the addition of boric acid (H3BO3). The microstructure dependence of LPD SiO2 films on solution parameters and deposition temperature was systematically investigated. The dielectric constant is lower than that of thermal SiO2, resulting from the fluorine doping. The remarkably low dielectric constant, relatively low leakage current and fairly high elastic modulus make these low temperature processed LPD SiO2 films very promising for an interlayer dielectric for flexible substrates. Using the same LPD method, smooth SnO2 films were deposited on both silicon and glass substrates at 60 �C through supersaturated solutions of SnF 2 with a concentration range from 10 mM to 40 mM. They consist of nanoscale crystallites and the degree of crystallinity increase with annealing temperature. A hydrothermal process was employed to deposit ZnO films for energy harvesting devices. A polymer mask was patterned on top of a zinc acetate seed layer to generate a regular array of open holes (200 nm in diameter) using a nanoimprint. Vertically aligned ZnO nanorod arrays were grown on these open holes that expose the seed layer. The morphology and microstrucutre of the nanorods were studied according to chemical composition of the solution. Equimolar reduce of the concentration of ZnAc and HMTA results in decrease in nanorod diameter, as well as in length. The nanorods become thinner and slightly better aligned with decreased HMTA concentration, and thicker rods and faster deposition rate were observed for increased HMTA concentration. Temperature plays a critical role and nanorods gown at 90 �C seems to have better alignment than those grown at 80 �C. More process optimization will be needed to achieve the controlled growth of nanorod structures.
Yu, Shijun
Dependence of transition temperature on hole concentration per CuO2 sheet in the Bi-based superconductors
The recently observed variations of the transition temperature (T sub c) with oxygen content in the Bi based (2212) and (2223) superconductors are analyzed in terms of p+, the hole concentration per CuO2 sheet. This analysis shows that in this system, T sub c increases with p+ initially, reaching maxima at p+ = 0.2 approx. 0.3, followed by monotonic decrease of T sub c with p+. The forms of these variations are similar to those observed in the La(2-x)Sr(x)CuO4 and YBa2Cu3Oy systems, suggesting that p+ may be an important variable governing superconductivity in the cuprate superconductors.
Zhao, J.; Seehra, M. S.
Development of 10 kA high temperature superconducting power cable for railway systems
The superconducting Bi2Sr2Ca2Cu3Oy ``Bi-2223'' tapes made with a powder-in-tube process laminated with a copper alloy have been used to design and develop a 5 m long multilayer concentric cable to be applied in railway systems. The electrical performance of the conductor has been evaluated with DC transport current at an economical 77 K (liquid nitrogen temperature) in the self-field. The inner and outer sheet wires were able to sustain electric currents of 10 130 A and 10 910 A, respectively. These values are sufficient for several types of commercial applications. The current values are significantly higher than the earlier reported ones in Bi-2223 or YBa2Cu3Oy ``Y-123'' superconducting cables, indicating that the tape quality has considerably improved.
Tomita, M.; Muralidhar, M.; Suzuki, K.; Fukumoto, Y.; Ishihara, A.
Significant improvement of trapped flux in bulk Gd-Ba-Cu-O grains fabricated by a modified top-seeded melt growth process
The seeded infiltration and growth of Gd-Ba-Cu-O single grains using a YBa2Cu3Oy pressed pellet as the liquid source has successfully solved the liquid source leakage problem even at Tmax � 1100?�C. As a development of this process, a simple but essential modification to insert a liquid source pellet at the bottom of the pre-form was made to the top-seeded melt growth process. The present method resulted in a significant enhancement of the trapped flux density of the Gd-Ba-Cu-O grains. In the growth kinetics, we interpreted that the enriched liquid source surrounding the growth front leads to a more uniform distribution of Gd2BaCuO5 in the matrix and an enlarged c-orientation growth area, which help suppress the formation of high angle grain boundaries. Furthermore, we demonstrated that the present method is of great advantage in multi-seeded processes.
Zhou, Difan; Hara, Shogo; Li, Beizhan; Xu, Kun; Noudem, Jacques; Izumi, Mitsuru
X-Ray Diffraction Observations of a Charge-Density-Wave Order in Superconducting Ortho-II YBa2Cu3O6.54 Single Crystals in Zero Magnetic Field
X-ray diffraction measurements show that the high-temperature superconductor YBa2Cu3O6.54, with ortho-II oxygen order, has charge-density-wave order in the absence of an applied magnetic field. The dominant wave vector of the charge density wave is qCDW=(0,0.328(2),0.5), with the in-plane component parallel to the b axis (chain direction). It has a similar incommensurability to that observed in ortho-VIII and ortho-III samples, which have different dopings and oxygen orderings. Our results for ortho-II contrast with recent high-field NMR measurements, which suggest a commensurate wave vector along the a axis. We discuss the relationship between spin and charge correlations in YBa2Cu3Oy and recent high-field quantum oscillation, NMR, and ultrasound experiments.
Blackburn, E.; Chang, J.; H�cker, M.; Holmes, A. T.; Christensen, N. B.; Liang, Ruixing; Bonn, D. A.; Hardy, W. N.; R�tt, U.; Gutowski, O.; Zimmermann, M. v.; Forgan, E. M.; Hayden, S. M.
Broken rotational symmetry in the pseudogap phase of a high-Tc superconductor
The nature of the pseudogap phase is a central problem in the quest to understand high-Tc cuprate superconductors. A fundamental question is what symmetries are broken when that phase sets in below a temperature T^*. Here we report the observation of a large in-plane anisotropy of the Nernst effect in YBa2Cu3Oy that sets in precisely at T^*, throughout the doping phase diagram [1]. We show that the CuO chains of the orthorhombic lattice are not responsible for this anisotropy, which is therefore an intrinsic property of the CuO2 planes. We conclude that the pseudogap phase is an electronic state which strongly breaks four-fold rotational symmetry.[4pt] [1] R. Daou et al., arXiv:0909.4430
Chang, J.; Daou, R.; Leboeuf, D.; Cyr-Choiniere, O.; Laliberte, F.; Doiron-Leyraud, N.; Ramshaw, B. J.; Liang, R.; Bonn, D. A.; Hardy, W. N.; Taillefer, L.
Pseudogap temperature from quasiparticle Nernst effect in La-based cuprates
We compare the Nernst effect in stripe ordered Eu-doped La2-xSrxCuO4 (Eu-LSCO) and similarly hole-doped LSCO. We show that at high temperatures they have essentially the same temperature dependence, showing an upturn and sign change starting at a temperature T?. Relating T? to the pseudogap temperature T^, we present a general phase diagram for LSCO showing that T^ decreases as the doping increases until it is driven to zero within the superconducting dome. We compare the phase diagram and the T^ line to the similar ones of YBa2Cu3Oy shown in a recent study [1]. [1] R. Daou et al., arXiv:0909.4430
Cyr-Choini�re, O.; Daou, R.; Lalibert�, F.; Le Boeuf, D.; Doiron-Leyraud, N.; Chang, J.; Pyon, S.; Takayama, T.; Takagi, H.; Tanaka, Y.; Taillefer, L.
Decrease of upper critical field with underdoping in cuprate superconductors
It is still unclear why the transition temperature Tc of cuprate superconductors falls with underdoping. The doping dependence of the critical magnetic field Hc2 is directly relevant to this question, but different estimates of Hc2 are in sharp contradiction. We resolve this contradiction by tracking the characteristic field scale of superconducting fluctuations as a function of doping, via measurements of the Nernst effect in La1.8-xEu0.2SrxCuO4. Hc2 is found to fall with underdoping, with a minimum where stripe order is strong. The same non-monotonic behaviour is observed in the archetypal cuprate superconductor YBa2Cu3Oy. We conclude that competing states such as stripe order weaken superconductivity and cause both Hc2 and Tc to fall as cuprates become underdoped.
Chang, J.; Doiron-Leyraud, N.; Cyr-Choini�re, O.; Grissonnanche, G.; Lalibert�, F.; Hassinger, E.; Reid, J.-Ph.; Daou, R.; Pyon, S.; Takayama, T.; Takagi, H.; Taillefer, Louis
Doping dependence of the normal-state Hall coefficient in YBCO
We report on the doping dependence of the normal-state Hall coefficient RH(T) in the high-Tc superconductor YBa2Cu3Oy for 0.08 < p < 0.15, measured in magnetic fields up to 60 T. RH(T) is seen to drop below a temperature TH, to become negative at low temperature, as previously reported for two dopings (1). We attribute this drop to a reconstruction of the Fermi-surface caused by the onset of broken translational symmetry, which produces an electron-like pocket in the Fermi surface of underdoped YBCO. The fact that TH peaks at p = 1/8 strongly suggests that Fermi-surface reconstruction is caused by stripe order. (1) D. LeBoeuf et al., Nature 450, 533 (2007).
Leboeuf, David; Doiron-Leyraud, Nicolas; Lalibert�, Francis; Cyr-Choini�re, Olivier; Daou, Ramzy; Taillefer, Louis; Vignolle, Baptiste; Levallois, Julien; Proust, Cyril; Ramshaw, B. J.; Bonn, D. A.; Hardy, W. N.; Liang, Ruixing; Balicas, L.; Jo, Y. J.
Batch Production of YBCO Disks for Levitation Applications
Batch melt-growth processing of YBa2Cu3Oy levitation disks cold seeded by Sm-123 single crystals doped by MgO is described. The process capable of a simultaneous fabrication of up to 64 pieces has been developed and successfully tested as a necessary step towards a planned production capacity of several thousand pieces a year. Diameters of the levitation disks varied from 14 mm to 56 mm. Main attention was paid to levitation disks of 28 mm in diameter. This dimension occurs to be the best compromise from various points of view: the material homogeneity, pellet quality, production loss, processing time etc. Properties of the disks, such as levitation force, critical current density at different temperatures, trapped magnetic field, etc. are shown and discussed.
Plechacek, V.; Jirsa, M.; Rames, M.; Muralidhar, M.
Probing commensurate ground states of Josephson vortex in layered superconductors.
Because of the commensurability condition between the vortex lattice constant determined by external magnetic field and the nano-scale layered structure, interlayer Josephson vortices (JVs) in high-Tc cuprate superconductors can take various configurations. We have simulated with Langevin scheme the in-plane flux-flow dynamics of JVs subject to point-like pinning centers. Oscillation in resistivity is found with the applied magnetic field, where the resistivity peaks occur around commensurate JV configurations. We have also measured the resistivity experimentally using single crystals of underdoped YBa2Cu3Oy with the anisotropy parameter gamma approximately equal to 50. A unique JV lattice has been detected for the first time. PMID:24734701
Takahashi, Y; Luo, M-B; Nishizaki, T; Kobayashi, N; Hu, X
Triple-band high-temperature superconducting microstrip filter based on multimode split ring resonator
A compact triple-band high-temperature superconducting (HTS) YBa2Cu3Oy microstrip bandpass filter using multimode split ring resonator (SRR) is presented in this letter. Also, its properties and equivalent circuit models are investigated by even- and odd-mode analysis. Moreover, design method of the proposed triple-band HTS filter for the applications of global positioning system at 1.57 GHz, worldwide interoperability for microwave access at 3.5 GHz, and wireless local area networks at 5.8 GHz is discussed. The centre frequencies and the bandwidths of the three passbands can be allocated properly choosing the dimension parameters of the multimode SRR. In addition, four transmission zeros are produced to improve the selectivity of this filter.
Liu, Hai-Wen; Wang, Yan; Fan, Yi-Chao; Guan, Xue-Hui; He, Yusheng
Development of molecular precursors for deposition of indium sulphide thin film electrodes for photoelectrochemical applications.
Symmetrical and unsymmetrical dithiocarbamato pyridine solvated and non-solvated complexes of indium(III) with the general formula [In(S2CNRR')3]�n(py) [where py = pyridine; R,R' = Cy, n = 2 (1); R,R' = (i)Pr, n = 1.5 (2); NRR' = Pip, n = 0.5 (3) and R = Bz, R' = Me, n = 0 (4)] have been synthesized. The compositions, structures and properties of these complexes have been studied by means of microanalysis, IR and (1)H-NMR spectroscopy, X-ray single crystal and thermogravimetric (TG/DTG) analyses. The applicability of these complexes as single source precursors (SSPs) for the deposition of ?-In2S3 thin films on fluorine-doped SnO2 (FTO) coated conducting glass substrates by aerosol-assisted chemical vapour deposition (AACVD) at temperatures of 300, 350 and 400 �C is studied. All films have been characterized by powder X-ray diffraction (PXRD) and energy dispersive X-ray analysis (EDX) for the detection of phase and stoichiometry of the deposit. Scanning electron microscopy (SEM) studies reveal that precursors (1)-(4), irrespective of different metal ligand design, generate comparable morphologies of ?-In2S3 thin films at different temperatures. Direct band gap energies of 2.2 eV have been estimated from the UV-vis spectroscopy for the ?-In2S3 films fabricated from precursors (1) and (4). The photoelectrochemical (PEC) properties of ?-In2S3 were confirmed by recording the current-voltage plots under light and dark conditions. The plots showed anodic photocurrent densities of 1.25 and 0.65 mA cm(-2) at 0.23 V vs. Ag/AgCl for the ?-In2S3 films made at 400 and 350 �C from the precursors (1) and (4), respectively. The photoelectrochemical performance indicates that the newly synthesised precursors are highly useful in fabricating ?-In2S3 electrodes for solar energy harvesting and optoelectronic application. PMID:23787951
Ehsan, Muhammad Ali; Peiris, T A Nirmal; Wijayantha, K G Upul; Olmstead, Marilyn M; Arifin, Zainudin; Mazhar, Muhammad; Lo, K M; McKee, Vickie
Reaction sintering of fluorine-doped MgSiN 2
Reaction bonded MgSiN2 (RBMSN) with CaF2 and YbF3, as sintering additives was prepared by direct nitridation of Si\\/Mg2Si\\/Mg\\/Si3N4 powder compact in a temperature range 1350�1550��C. The influence of the ratio of constituents on the final phase composition, the amount of sintering additives and the influence of sintering temperature are discussed. It was shown that the starting powders should be in
Z. Len?�; K. Hirao; S. Kanzaki; M. J. Hoffmann; P. �ajgal??k
Fluorine doping in dilute magnetic semiconductor Sn1�xFexO2
Recent studies have reported room-temperature ferromagnetism (FM) in Fe doped SnO2. The FM in semiconductors due to transition metal doping has been argued to be carrier mediated. Fluorine (F) doping in sure SnO2 has been reported to significantly increase the carrier concentration. In this work, we investigated the role of F doping in the range from 0% to 0.79% on
Aaron Thurber; Jason Hays; K. M. Reddy; V. Shutthanandan; Alex Punnoose
Recent studies have reported room-temperature ferromagnetism (FM) in Fe doped SnO2. The FM in semiconductors due to transition metal doping has been argued to be carrier mediated. Fluorine (F) doping in sure SnO2 has been reported to significantly increase the carrier concentration. In this work, we investigated the role of F doping in the range from 0% to 0.79% on the FM of chemically synthesized single phase Sn1xFexO2 using X-ray diffraction, UV-Vis spectrophotometry, particle-induced X-ray emission, particle-induced gamma ray emission and magnetometry. The saturation magnetization Ms (0.03 emu/g) increased by a factor of 2.5 and the lattice volume and band gap energy decreased by 0.35 A3 and 0.2eV, respectively, with 0.67% F doping (F/Sn atom %) compared to the sample without any fluorine.
Thurber, A.; Hays, Jason; Reddy, K. M.; Shutthanandan, V.; Punnoose, Alex
Film Reviews.
ERIC Educational Resources Information Center
Reviews four Human Sexuality films and videos. These are: "Personal Decisions" (Planned Parenthood Federation of America, 1985); "The Touch Film" (Sterling Production, 1986); "Rethinking Rape" (Film Distribution Center, 1985); "Not A Love Story" (National Film Board of Canada, 1981). (AEM)
Lance, Larry M.; Atwater, Lynn
Thin films
NSDL National Science Digital Library
This simulation illustrates the behavior of thin films for reflected light. The user can change the angle of the incident beam, the thickness of the thin film and the type of thin film used. Two types of thin film are allowed.
Renault, Pascal
Fluorine-doping concentration and fictive temperature dependence of self-trapped holes in SiO2 glasses
Fictive temperature (Tf) and fluorine (F)-doping concentration dependences of self-trapped holes (STHs) in silica glasses created by UV irradiation at low temperatures have been studied by the electron-paramagnetic-resonance method. It was found that the yield of STH decreases with decreasing Tf and increasing F-doping concentration. In combination with infrared spectra measurements, the correlation among Tf, F-doping concentration, Si-O bond length, and Si-O-Si bond angle was elucidated. We conclude that the change in both Tf and F doping can modify the network of SiO2 glass, leading to the suppression of the formation of STHs.
Wang, R. P.; Tai, N.; Saito, K.; Ikushima, A. J.
Effect of fluorine doping on the properties of tin oxide based powders prepared via Pechini�s method
Surface modification of ceramic powders is an important method to change and control the properties of the material. Grain size, surface charge density and consequently the powder�surroundings interfacial properties can be modified by the use of additives. The surface properties of SnO2-based powders doped with F, prepared via an organic chemical route derived from Pechini�s method, was studied using infrared
M. C. Esteves; D. Gouv�a; P. T. A. Sumodjo
Fluorine-doping concentration and fictive temperature dependence of self-trapped holes in SiO{sub 2} glasses
Fictive temperature (T{sub f}) and fluorine (F)-doping concentration dependences of self-trapped holes (STHs) in silica glasses created by UV irradiation at low temperatures have been studied by the electron-paramagnetic-resonance method. It was found that the yield of STH decreases with decreasing T{sub f} and increasing F-doping concentration. In combination with infrared spectra measurements, the correlation among T{sub f}, F-doping concentration, Si-O bond length, and Si-O-Si bond angle was elucidated. We conclude that the change in both T{sub f} and F doping can modify the network of SiO{sub 2} glass, leading to the suppression of the formation of STHs.
Wang, R.P.; Tai, N.; Saito, K.; Ikushima, A.J. [Research Center for Advanced Photon Technology, Toyota Technological Institute, 2-12-1 Hisakata, Tempaku, Nagoya 468-8511, Japan and Laser Physics Centre, Research School of Physical Science and Engineering, Australian National University, Canberra ACT 0200 (Australia); Research Center for Advanced Photon Technology, Toyota Technological Institute, 2-12-1 Hisakata, Tempaku, Nagoya 468-8511 (Japan)
Humanistic Films.
Designed for media specialists and educators, this issue includes seven articles focusing on humanistic films for children. Following a brief editorial encouraging the ideals of humanism, the first article presents an analysis of seven films with positive...
M. Gaffney
Film Reviews
Reviews five instructional films on: P-N junctions; crystal diodes; nuclear fusion research; Schlieren photography; and the energy crisis; including discussions of solar, nuclear, and fossil fuel energy. Also lists numerous other available films. (MLH)
Dowling, John, Ed.
Film Boxes.
Presents an art lesson in which students created three-dimensional designs for 35mm film packages to improve graphic arts learning. Describes how the students examined and created film boxes using QuarkXPress software. (CMK)
Osterer, Irv
Assessments of Microbiology Films (Part I)Films for TeachingBacteriological Techniques. (2 parts) 81-004 and 81-005, Film-loop, colour, 7 min 45 sec Produced by Thorne\\/BSCS: U.S.A. 1964Microtechniques. (1) dilution plating (2) inoculation with a loop, Film loops, colour, (1) 3 min 50 sec, (2) 1 min 15 sec. Produced by Nuffield Foundation Science Teaching Project: U.K. 1966Neurospora Techniques. (2 parts) 81-007 and
H. V. Wyatt
On Film
In this article, the author discusses the role of window films in enhancing indoor air quality in schools. Historically, window film has been used to reduce temperatures in buildings prone to overheating. Too much solar energy entering through windows makes occupants uncomfortable and air conditioning more costly. Film has been a simple solution�
Watts, Marty
Nanocomposite films
A thin-film composition of nanocrystal molybdenum in an amorphous metallic matrix may be formed by co-sputtering Mo with aluminum or nickel. NEMS cantilevers may be formed from the film. The films exhibit high nanoindentation hardness and a reduction in roughness and intrinsic stress, while maintaining resistivity in the metallic range.
Mitlin, David (Edmonton, CA) [Edmonton, CA; Ophus, Colin (Edmonton, CA) [Edmonton, CA; Evoy, Stephane (Edmonton, CA) [Edmonton, CA; Radmilovic, Velimir (Piedmont, CA) [Piedmont, CA; Mohammadi, Reza (Edmonton, CA) [Edmonton, CA; Westra, Ken (Edmonton, CA) [Edmonton, CA; Nelson-Fitzpatrick, Nathaniel (Edmonton, CA) [Edmonton, CA; Lee, Zonghoon (Albany, CA) [Albany, CA
Patterning of periodic high-aspect-ratio nanopores in anatase titanium dioxide from titanium fluoride hydrolysis.
We report straight pores in titanium dioxide produced by a pattern transfer method with titanium fluoride hydrolysis. The resulting films on fluorine-doped tin oxide had pores with diameters of 30 nm and depths of 500 nm, corresponding to aspect ratios of 1:17. PMID:21468391
Tevis, Ian D; Stupp, Samuel I
Film tourism
\\u000a The following chapter will introduce the reader into the relatively new and growing tourism niche �Film Tourism� by giving\\u000a you an overview of the whole topic. Film tourism can be defined as a branch of cultural tourism (Zimmermann, 2003, p.76) and\\u000a refers to the growing interest and demand for locations which became popular due to their appearance in films and
Karolina Tomala; Florence Faber
Anodic films
Surface layers are formed on many metals by anodic reaction. Such layers include the products of charge and discharge in many storage batteries, dielectric films used in electronic and optical circuits and display devices, layers responsible for passivity and corrosion protection, and films generated in metal shaping and finishing operations such as anodization, coloring, electropolishing, electrochemical machining and deburring. Anodic films are formed by solid-solid transformations or by dissolution-precipitation processes. Film properties and mechanisms of formation can be determined in situ by a number of optical techniques which have recently become available.
Muller, R.H.
Film ispalators
New physical objects, ispalators based on free soap films, exhibit persistent flows of the soap solution in open and closed volumes in air with additions of gases of the C{sub 8}F{sub 18} type (p = 20 Torr) at temperature drops on the films of the order of tenths and hundredths of kelvin. The flows move continuously at a velocity of 5 - 20 cm s{sup -1}. It is found that the parts of an inclined ispalator film show anomalous behaviour upon heating: their weight increases and they move downward over the film, whereas the unheated parts of the film move upward. Continuous radial vortex flows accompanied by the formation and washing of the regions of a thin black film are observed on circular films in closed volumes upon their uniform external cooling by evaporating water for 5 - 10 hours. The rapid flows make film ispalators the efficient heat carriers, which operate at small temperature drops (tenths and hundredths of kelvin) and surpass copper in the amount of thermal energy being transferred. The outlook for the further study and applications of film ispalators for detecting thermal fields and laser radiation is discussed. (laser applications and other topics in quantum electronics)
Startsev, Aleksandr V; Stoilov, Yurii Yu [P.N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)
Effect of [Cu]\\/[Cu + In] ratio in the solution bath on the growth and physical properties of CuInS 2 film using one-step electrodeposition
Copper indium disulfide (CuInS2) semiconductor layers were deposited on fluorine doped tin oxide coated glass substrates using one-step electrodeposition. The effect of the [Cu]\\/[Cu+In] molar ratio in the solution bath on the structural, optical, and electrical properties of samples was investigated. X-ray diffraction patterns and energy dispersive analysis of X-ray results reveal that the samples changed from the In-rich CuInS2
Kong-Wei Cheng; Wei-Hao Chiang
About Films.
Lists and briefly describes 46 college-level films. Films are arranged in the following categories: volcanism and earthquakes; plate tectonics; energy, water, and environmental concerns; petroleum and coal; astronomy; space exploration, space shuttle; paleontology; geomorphology; and mineralogy, petrology, and economic geology. (BC)
Christman, Robert; Krockover, Gerald H.
Ephemeral Films
Ephemeral films are those films that are made "for educational, industrial, or promotional purposes" and they are a specialty over at the Internet Archive. This delightful collection is both informative and amusing and contains over 200 of these films. Visitors can view the "Most Downloaded Items Last Week" to get a sense of the wisdom of the crowds, or they can go their own way by browsing by subject or keyword. The site has a number of sub-collections, including one dedicated to drive-in movie ads and public information films created by the British government. Visitors shouldn't miss the public service announcements by the U.S. Civil Defense office aimed at farmers (the "actors" are marionettes) or the "Beginning Responsibility: Lunchroom Manners" instructional film.
Film Makers On Film Making.
This collection includes essays by and interviews with more than 30 film-makers, both classic and contemporary, on the subjects of their major interests and procedures in making films. The directors are: Louis Lumiere, Cecil Hepworth, Edwin S. Porter, Mack Sennett, David W. Griffith, Robert Flaherty, Charles Chaplin, Eric von Stroheim, Dziga�
Geduld, Harry M., Ed.
Synthesis and characterization of highly stable optically passive CeO 2�ZrO 2 counter electrode
Transparent and adherent CeO2�ZrO2 thin films having film thicknesses ?543�598nm were spray deposited onto the conducting (fluorine doped tin oxide coated glass) substrates from a blend of equimolar concentrations of cerium nitrate hexahydrate and zirconium nitrate having different volumetric proportions (0�6vol.% of Zr) in methanol. CeO2�ZrO2 films were polycrystalline with cubic fluorite crystal structure and the crystallinity was improved with
A. K. Bhosale; P. S. Shinde; N. L. Tarwal; R. C. Pawar; P. M. Kadam; P. S. Patil
Piezoelectric Film.
Presents activities that utilize piezoelectric film to familiarize students with fundamental principles of electricity. Describes classroom projects involving chemical sensors, microbalances, microphones, switches, infrared sensors, and power generation. (MDH)
Garrison, Steve
Briefly describes films about the following topics: water cycles, the energy crisis, the eruption of Mt. Aetna, the hot springs of Yellowstone National Park, and methods of using pine cones to determine the ages of ancient civilizations. (MLH)
Ladd, George T.
Film Making
Below are a list of useful sites, tutorials, and resources that will guide you through the filmmaking process. Click on this link to find out about the three different stages of film production. Preproduction, production, and postproduction VIDEO EDITING TUTORIALS If you are part of the special effects and film editing team, you won\\'t want to miss these. Click here to find out how to use a green screen to make different backgrounds for your ...
Allan, Mrs.
Hall and Nernst Coefficients of Underdoped HgBa2CuO4+?: Fermi-Surface Reconstruction in an Archetypal Cuprate Superconductor
The Hall coefficient RH of underdoped HgBa2CuO4+? (Hg1201) was measured at low temperature in magnetic fields large enough to suppress superconductivity. The normal-state RH(T) is found to drop with decreasing temperature and become negative below 10 K, as also observed in the orthorhombic bi-layer cuprate YBa2Cu3Oy (YBCO) at comparable doping. In YBCO, the negative RH is the signature of a Fermi-surface reconstruction that produces a small electron pocket, attributed to the onset of charge-density wave order at low temperature. We infer that a similar Fermi-surface reconstruction occurs in the tetragonal single-layer material Hg1201. A striking similarity is also found in the normal-state Nernst coefficient ?(T), which drops below the pseudogap temperature T^, to reach a large negative value at low temperature, in both Hg1201 and YBCO. Our results are compelling evidence that the mechanisms responsible for Fermi-surface reconstruction and pseudogap formation in hole-doped cuprates are universal. Preprint reference: arXiv:1210.8411.
Doiron-Leyraud, Nicolas; Lepault, S.; Cyr-Choini�re, O.; Vignolle, B.; Lalibert�, F.; Chang, J.; Bari�i?, N.; Chan, M. K.; Ji, L.; Zhao, X.; Li, Y.; Greven, M.; Proust, C.; Taillefer, Louis
Nernst and Seebeck Coefficients of the Cuprate Superconductor YBa2Cu3O6.67: A Study of Fermi Surface Reconstruction
The Seebeck and Nernst coefficients S and ? of the cuprate superconductor YBa2Cu3Oy (YBCO) were measured in a single crystal with doping p=0.12 in magnetic fields up to H=28T. Down to T=9K, ? becomes independent of field by H?30T, showing that superconducting fluctuations have become negligible. In this field-induced normal state, S/T and ?/T are both large and negative in the T?0 limit, with the magnitude and sign of S/T consistent with the small electronlike Fermi surface pocket detected previously by quantum oscillations and the Hall effect. The change of sign in S(T) at T?50K is remarkably similar to that observed in La2-xBaxCuO4, La2-x-yNdySrxCuO4, and La2-x-yEuySrxCuO4, where it is clearly associated with the onset of stripe order. We propose that a similar density-wave mechanism causes the Fermi surface reconstruction in YBCO.
Chang, J.; Daou, R.; Proust, Cyril; Leboeuf, David; Doiron-Leyraud, Nicolas; Lalibert�, Francis; Pingault, B.; Ramshaw, B. J.; Liang, Ruixing; Bonn, D. A.; Hardy, W. N.; Takagi, H.; Antunes, A. B.; Sheikin, I.; Behnia, K.; Taillefer, Louis
Hall, Seebeck, and Nernst Coefficients of Underdoped HgBa2CuO4+?: Fermi-Surface Reconstruction in an Archetypal Cuprate Superconductor
Charge-density-wave order has been observed in cuprate superconductors whose crystal structure breaks the square symmetry of the CuO2 planes, such as orthorhombic YBa2Cu3Oy (YBCO), but not so far in cuprates that preserve that symmetry, such as tetragonal HgBa2CuO4+? (Hg1201). We have measured the Hall (RH), Seebeck (S), and Nernst (?) coefficients of underdoped Hg1201 in magnetic fields large enough to suppress superconductivity. The high-field RH(T) and S(T) are found to drop with decreasing temperature and become negative, as also observed in YBCO at comparable doping. In YBCO, the negative RH and S are signatures of a small electron pocket caused by Fermi-surface reconstruction, attributed to charge-density-wave modulations observed in the same range of doping and temperature. We deduce that a similar Fermi-surface reconstruction takes place in Hg1201, evidence that density-wave order exists in this material. A striking similarity is also found in the normal-state Nernst coefficient ?(T), further supporting this interpretation. Given the model nature of Hg1201, Fermi-surface reconstruction appears to be common to all hole-doped cuprates, suggesting that density-wave order is a fundamental property of these materials.
Doiron-Leyraud, Nicolas; Lepault, S.; Cyr-Choini�re, O.; Vignolle, B.; Grissonnanche, G.; Lalibert�, F.; Chang, J.; Bari�i?, N.; Chan, M. K.; Ji, L.; Zhao, X.; Li, Y.; Greven, M.; Proust, C.; Taillefer, Louis
Nodal quasiparticle dynamics in the heavy fermion superconductor CeCoIn5 revealed by precision microwave spectroscopy
CeCoIn5 is a heavy fermion superconductor with strong similarities to the high-Tc cuprates, including quasi-two-dimensionality, proximity to antiferromagnetism and probable d-wave pairing arising from a non-Fermi-liquid normal state. Experiments allowing detailed comparisons of their electronic properties are of particular interest, but in most cases are difficult to realize, due to their very different transition temperatures. Here we use low-temperature microwave spectroscopy to study the charge dynamics of the CeCoIn5 superconducting state. The similarities to cuprates, in particular to ultra-clean YBa2Cu3Oy, are striking: the frequency and temperature dependence of the quasiparticle conductivity are instantly recognizable, a consequence of rapid suppression of quasiparticle scattering below Tc; and penetration-depth data, when properly treated, reveal a clean, linear temperature dependence of the quasiparticle contribution to superfluid density. The measurements also expose key differences, including prominent multiband effects and a temperature-dependent renormalization of the quasiparticle mass.
Truncik, C. J. S.; Huttema, W. A.; Turner, P. J.; �zcan, S.; Murphy, N. C.; Carri�re, P. R.; Thewalt, E.; Morse, K. J.; Koenig, A. J.; Sarrao, J. L.; Broun, D. M.
Optical Birefringence and Dichroism of Cuprate Superconductors in the THz Regime
The presence of optical polarization anisotropies, such as Faraday or Kerr effects, linear birefringence, and magnetoelectric birefringence are evidence for broken symmetry states of matter. The recent discovery of a Kerr effect using near-IR light in the pseudogap phase of the cuprates can be regarded as a strong evidence for a spontaneous symmetry breaking and the existence of an anomalous long-range ordered state. In this work we present a high precision study of the polarimetry properties of the cuprates in the THz regime. While no Faraday effect was found in this frequency range to the limits of our experimental uncertainty (1.3 milli-radian or 0.07�), a small but significant polarization rotation was detected that derives from an anomalous linear dichroism. In YBa2Cu3Oy the effect has a temperature onset that mirrors the pseudogap temperature T* and is enhanced in magnitude in underdoped samples. In x =1/8 La2-xBaxCuO4, the effect onsets above room temperature, but shows a dramatic enhancement near a temperature scale known to be associated with spin- and charge-ordered states. These features are consistent with a loss of both C4 rotation and mirror symmetry in the electronic structure of the CuO2 planes in the pseudogap state.
Lubashevsky, Y.; Pan, LiDong; Kirzhner, T.; Koren, G.; Armitage, N. P.
Optical Birefringence and Dichroism of Cuprate Superconductors in the THz Regime.
The presence of optical polarization anisotropies, such as Faraday or Kerr effects, linear birefringence, and magnetoelectric birefringence are evidence for broken symmetry states of matter. The recent discovery of a Kerr effect using near-IR light in the pseudogap phase of the cuprates can be regarded as a strong evidence for a spontaneous symmetry breaking and the existence of an anomalous long-range ordered state. In this work we present a high precision study of the polarimetry properties of the cuprates in the THz regime. While no Faraday effect was found in this frequency range to the limits of our experimental uncertainty (1.3 milli-radian or 0.07�), a small but significant polarization rotation was detected that derives from an anomalous linear dichroism. In YBa2Cu3Oy the effect has a temperature onset that mirrors the pseudogap temperature T* and is enhanced in magnitude in underdoped samples. In x=1/8 La2-xBaxCuO4, the effect onsets above room temperature, but shows a dramatic enhancement near a temperature scale known to be associated with spin- and charge-ordered states. These features are consistent with a loss of both C4 rotation and mirror symmetry in the electronic structure of the CuO2 planes in the pseudogap state. PMID:24766004
Lubashevsky, Y; Pan, Lidong; Kirzhner, T; Koren, G; Armitage, N P
Science Fiction on Film.
Reviews science fiction films used in a science fiction class. Discusses feature films, short science fiction films, short story adaptations, original science fiction pieces and factual science films that enrich literature. (EL)
Burmester, David
This volume is a compilation of papers presented at the 1990 Spring Meeting of the Materials Research Society in a symposium entitled Thin Films: Stresses and Mechanical Properties II. As indicated by the title, the symposium was the second in a series, the first of which was held at the Fall Meeting in 1988. The importance of thin film mechanical properties is now recognized to the extent that basic characterization techniques such as microindentation and thin film stress measurement are performed routinely, and new characterization techniques are being developed on a daily basis. Many of the papers in the symposium dealt with the developments in these characterization methods and their application to a broad spectrum of materials such as compositionally modulated structures, ion implanted materials, optical coatings, and the numerous metals, ceramics and organics used in semiconductor device manufacture.
Doermer, M.F. (International Business Machines Corp., San Jose, CA (United States)); Oliver, W.C. (Oak Ridge National Lab., TN (United States)); Pharr, G.M.; Brotzen, F.R. (Rice Univ., Houston, TX (United States))
Film Festivals
Now that the Oscars and Golden Globes have all been awarded, some cineastes may think that the season of film celebration, award shows, and festivals is in a quiet slumber for a few months. Nothing could be farther from the truth, and a quick glance at the Film Festival website quickly dispels that misconception. Online since 1995, the site provides a great resource about previous and upcoming film festivals from all over the world. Here visitors can read the latest headline news from the various festivals, read coverage of the proceedings, and search a prodigious database of information. Visitors may also want to consider signing up to receive the free weekly newsletter or also viewing a selection of popular video clips culled from coverage of recent festivals.
Rainbow Film
In this activity, learners use clear nail polish to create a beautiful iridescent pattern on black paper. Learners discover that a thin film creates iridescent, rainbow colors. This is a very fun and engaging activity for learners, and a great way to talk about how nanoscale structures often affect a material's properties. SAFETY: Do this activity in a well-ventilated area.
Nifecu Films.
Alloy films produced by simultaneous deposition from two separate sources, one evaporating NiFe and the other evaporating Cu, can exhibit large oblique-incidence ferromagnetic anisotropy even for small incidence angles. For vapor beam angles of NiFe, high...
M. S. Cohen
Graphene nanosheet counter-electrodes for dye-sensitized solar cells
Graphene nanosheets (GNs) have been investigated as a counter electrode for dye-sensitized solar cells (DSCs). Mesoporous TiO2 films are prepared from the commercial TiO2 nano-powders by screen-printing technique on fluorine-doped tin oxide (FTO) slides. GNs are applied to substitute for platinum as counter-electrode materials. GN films are screen printed on FTO glass using a paste based on GNs dispersed in
D. W. Zhang; X. D. Li; S. Chen; H. B. Li; Z. Sun; X. J. Yin; S. M. Huang
Black Films and Film-Makers.
The development of black films and the attitudes of the film industry toward black films and black actors are some of the topics examined in this anthology of essays. Section 1, "Nigger to Supernigger," contains such articles as "The Death of Rastus: Negroes in American Films" by Thomas R. Cripps and "Folk Values in a New Medium" by Alain Locke�
Patterson, Lindsay, Ed.
Film and History.
Provides an annotated bibliography of Web sites that focus on using film to teach history. Includes Web sites in five areas: (1) film and education; (2) history of cinema; (3) film and history resources; (4) film and women; and (5) film organizations. (CMK)
Schaber, Robin L.
Ferroelectric ultrathin perovskite films
Disclosed herein are perovskite ferroelectric thin-film. Also disclosed are methods of controlling the properties of ferroelectric thin films. These films can be used in a variety materials and devices, such as catalysts and storage media, respectively.
Rappe, Andrew M; Kolpak, Alexie Michelle
Optimization of transparent and reflecting electrodes for amorphous-silicon solar cells. Final subcontract report, 1 May 1991--30 April 1994
Fluorine-doped zinc oxide was shown to have the lowest absorption loss of any of the known transparent conductors. An apparatus was constructed to deposit textured, transparent, conductive, fluorine-doped zinc oxide layers with uniform thickness over a 10 cm by 10 cm area, using inexpensive, high-productivity atmospheric pressure chemical vapor deposition. Amorphous silicon solar cells grown on these textured films show very high peak quantum efficiencies (over 90%). However, a significant contact resistance develops at the interface between the amorphous silicon and the zinc oxide. Transparent, conductive gallium-doped zinc oxide films were grown by APCVD at a low enough temperature (260{degree}C) to be deposited on amorphous silicon as a final conductive back contact to solar cells. A quantum-mechanical theory of bonding was developed and applied to some metal oxides; it forms a basis for understanding TCO structures and the stability of their interfaces with silicon.
Gordon, R.G.; Hu, J.; Lacks, D.; Musher, J.; Thornton, J.; Liang, H. [Harvard Univ., Cambridge, MA (United States)
Patterning of periodic high-aspect-ratio nanopores in anatase titanium dioxide from titanium fluoride hydrolysis
We report straight pores in titanium dioxide produced by a pattern transfer method with titanium fluoride hydrolysis. The resulting films on fluorine-doped tin oxide had pores with diameters of 30 nm and depths of 500 nm, corresponding to aspect ratios of 1 : 17.We report straight pores in titanium dioxide produced by a pattern transfer method with titanium fluoride hydrolysis. The resulting films on fluorine-doped tin oxide had pores with diameters of 30 nm and depths of 500 nm, corresponding to aspect ratios of 1 : 17. Electronic supplementary information (ESI) available: Detailed synthesis procedure and X-ray diffraction data. See DOI: 10.1039/c0nr01010c
Tevis, Ian D.; Stupp, Samuel I.
Film in Development.
The positive and negative aspects of using film as a medium for inducing change in developing nations are explored in this issue. Critics of the use of film for development cite (1) the culture specific nature of film content of foreign produced films; (2...
Hydrogen film cooling investigation
Effects of flow turning, flow acceleration, and supersonic flow on film cooling were determined experimentally and correlated in terms of an entrainment film cooling model. Experiments were conducted using thin walled metal test sections, hot nitrogen mainstream gas, and ambient hydrogen or nitrogen as film coolants. The entrainment film cooling model relates film cooling effectiveness to the amount of mainstream gases entrained with the film coolant in a mixing layer. The experimental apparatus and the analytical model used are described in detail and correlations for the entrainment fraction and film coolant-to-wall heat transfer coefficient are presented.
Rousar, D. C.; Ewen, R. L.
Archaeology on Film
Archaeology on Film, a database of archaeology film reviews, contains critical reviews of videos and films that are used as educational tools. The reviews in the database differ from simple synopses because they "focus on how films present archaeology in addition to what they present about archaeology." The database allows archaeology instructors to identify and compare relevant films quickly. Each film review provides title, date, format, running time, cost, subjects, and description. Archaeology on Film encourages instructors to submit reviews for inclusion in the database. A review form and standards for submission are available at the site.
Synthesis, growth mechanism and photoelectrochemical properties of BiVO4 microcrystal electrodes
BiVO4 films were deposited on fluorine-doped tin oxide substrates by chemical bath deposition. The samples were characterized by an x-ray diffractometer, UV-Vis transmission spectra and a scanning electron microscope. The morphologies of the samples were adjusted by the deposition time, temperature, pH of solution and buffer solution. When the temperature and pH value of the solution were high, the polyhedron
Wenjun Luo; Zhiqiang Wang; Lijuan Wan; Zhaosheng Li; Tao Yu; Zhigang Zou
Homogeneous interface-type resistance switching in Au\\/La0.67Ca0.33MnO3\\/SrTiO3\\/F:SnO2 heterojunction memories
La0.67Ca0.33MnO3 thin films are fabricated on fluorine-doped tin oxide conducting glass substrates by a pulsed laser deposition technique with SrTiO3 used as a buffer layer. The current-voltage characteristics of the heterojunctions exhibit an asymmetric and resistance switching behaviour. A homogeneous interface-type conduction mechanism is also reported using impedance spectroscopy. The spatial homogeneity of the charge carrier distribution leads to field-induced
Zhang Ting; Ding Ling-Hong; Zhang Wei-Feng
A novel CuInS2\\/polyaniline base heterojunction solar cell
Copper indium disulfide (CuInS2) has direct band-gap energy of about 1.5 eV and a large absorption coefficient, which are well suited to the photovoltaic conversion of solar energy. In this task a novel florin doped tin oxide (FTO)\\/CuInS2\\/ polyaniline base\\/ZnO\\/FTO heterojunction solar cell was fabricated. CuInS2 thin films were electrodeposited onto fluorine doped tin oxide substrate by the electrodeposition technique.
Sh. M. Ebrahim; I. Morsi; M. M. Soliman; M. Alshrkawy; A. A. Elzaem
Electrochromic devices based on wide band-gap nanocrystalline semiconductors functionalized with mononuclear charge transfer compounds
A series of ruthenium and iron mononuclear complexes were prepared and their spectroeletrochemical behavior characterized on Optically Transparent Thin Layer Electrodes (OTTLE) and on Fluorine Doped SnO2 (FTO) conductive glasses coated with Sb-doped nanocrystalline SnO2. These systems display a reversible electrochemical response and offer potential application in electrochromic devices. On SnO2 films distinct spectral changes are observed in a narrow
Matteo Biancardo; Roberto Argazzi; Carlo A. Bignozzi
Thin Film Interference Model
The Thin Film Interference model investigates reflection and transmission of light through a thin film. The user can change the thickness and index of refraction of the thin film as well as the incident light wavelength. The Thin Film Interference Model was created using the Easy Java Simulations (EJS) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_bu_ThinFilm.jar file will run the program if Java is installed.
Duffy, Andrew
Laminating Polyimide Films
Thermoplastic polyimide adhesive is used to bond polyimide sheets into flexible laminates. Films are first primed with polyimide adhesive, then bonded together under heat and pressure. Adhesive is cast on separate surface, then sandwiched between polyimide and/or metal films for final assembly. Objectives of process are to improve bonding of high-temperature polyimide film, prepare flexible, large-area, void-free laminates from polyimide film, and laminate polyimide film not only to itself but to metal surfaces.
St. Clair, A. K.; St. Clair, T. L.; Robinson, P. D.
Visible-light-driven photocatalysis on fluorine-doped TiO 2 powders by the creation of surface oxygen vacancies
F-doped TiO2 (FT) powders were prepared by spray pyrolysis from an aqueous solution of H2TiF6. These FT powders demonstrated very high visible-light (Vis) photocatalytic activities for decompositions of both acetaldehyde and trichloroethylene, although their UV�Vis spectra indicated that F-doping had less effect on the optical absorption property of bulk TiO2. However, photoluminescence (PL) spectra revealed that two kinds of oxygen
Di Li; Hajime Haneda; Nitin K. Labhsetwar; Shunichi Hishita; Naoki Ohashi
In situ control of phenol adsorption on conductive Pd-fluorine-doped tin dioxide-supported and Pd-alumina-supported catalysts in electrocatalytic hydrogenation.
In the context of the electrocatalytic hydrogenation (ECH) process of unsaturated organic molecules, we have shown using infrared spectroscopy and water contact angle measurements that catalysts powders made of palladium on conductive tin dioxide (10% Pd/SnO2:F) and on alumina (10% Pd/Al2O3) are functionalized with organic chains when they were dipped in supporting electrolyte aqueous solutions containing different carboxylic acids. The carboxylic acids are bound to the supports (SnO2:F and Al2O3) through either the carboxyl or carboxylate groups. The measurement of contact angles confirmed that the support surface is functionalized by the carboxylic acids but also indicated the hydrophobic or hydrophilic character of the resultant surface. With these functionalized catalysts, the effectiveness of electrocatalytic hydrogenation of phenol could be modulated by controlling the adsorption of phenol. The adsorption depends mainly on the functionalization agent (carboxylic acid) and to a lesser extent on the identity of the support material (SnO2:F or Al2O3). Because adsorption is the step that induces the selectivity of the ECH process, controlling this phenomenon by functionalizing the catalyst support in situ is promising for obtaining molecules of choice. PMID:19735154
Tountian, Dihourahouni; Brisach-Wittmeyer, Anne; Nkeng, Paul; Poillerat, G�rard; M�nard, Hugues
Thin film nano solar cells--from device optimization to upscaling.
Stainless steel based dye solar cells have been upscaled from small, laboratory size test cells of 0.32 cm2 active area to 6 cm x 6 cm "mini-modules" with active areas ca. 15 cm2. Stainless steel works as the photoelectrode substrate whilst the counter electrode is prepared on indium-doped tin oxide coated polyethyleneterephtalate or polyethylenenaphtalate plastic foil (fluorine-doped tin oxide coated glass as a reference). Additional current collector structures were deposited on the counter electrode substrate with inkjet-printing of silver nanoparticle ink in order to reduce the lateral resistance of the plastic foil. Flexible substrates enable roll-to-roll type industrial manufacturing of the cells and the steel's superior conductivity compared to the typical substrate materials such as glass and plastic makes it possible to prepare even substantially larger modules. The best efficiencies obtained this far with the "mini-module" using a stainless steel photoelectrode are 2.5% with a platinum-sputtered indium-doped tin oxide coated polyethyleneterephtalate counter electrode and 3.4% with a thermally platinized fluorine-doped tin oxide coated glass counter electrode. These efficiencies are on the same level than those measured with small cells prepared with similar methods and materials (3.4%-4.7%, depending on configuration, which are amongst the highest reported for this kind of a dye solar cell). Replacing expensive conducting glass with steel and plastic foils as the substrate materials leads also to economical savings in the cell production. PMID:20352759
Toivola, Minna; Peltola, Time; Miettunen, Kati; Halme, Janne; Lund, Peter
Resistance switching properties of sol-gel derived La0.67Ca0.33MnO3 thin films on F-doped SnO2 conducting glass
The electric-pulse-induced resistance switching of the Au-La0.67Ca0.33MnO3(LCMO)-FTO (fluorine-doped tin oxide) heterostructures was studied by electrochemical workstation. A distinct current-voltage characteristic of the device with pronounced reproducible nonlinearity, asymmetry, and hysteresis was observed at room temperature. The current-voltage characteristics suggest a Poole-Frenkel and space-charge-limited current type mechanism controlled by Au\\/LCMO interface traps. The resistance switching behavior shows obvious multilevel resistance switching.
Ting Zhang; Zhaohui Su; Hongju Chen; Linghong Ding; Weifeng Zhang
Using Folktale Films.
A model user's guide for the film, 'The Frog King or Faithful Henry,' introduces media specialists and educators to the range of possibilities for developing different activities for different objectives and age levels from a single film. An introductory ...
M. L. Fuchs M. Gaffney
Single Crystal Diamond Films.
Diamond films are important for radiation tolerant devices. However, fabrication of single crystal films has proven to be much more difficult than polycrystalline deposits. A novel deposition process is proposed which can be used to deposit diamond on a s...
S. N. Bunker R. Sahagian
Actuating porous polyimide films.
We report a novel method for the fabrication of one-component self-folding polymer films. The approach is based on films with a vertical gradient of porosity and was demonstrated on an example of porous polyimide films. The inhomogeneous porosity of the films was achieved through the implementation of capillary forces and gravity during the drying of a dispersion of colloidal particles in a solution of polymer precursor. As a result, three-layered films were formed. A monolayer of particles comprises the top layer, the second layer is the pure polymer, and the third layer is formed by a mixture of particles and polymer. Etching out the particles leaves polyimide film with inhomogeneous distributed pores. These porous polymer films roll and form tubes in organic solvents as well as their vapors and reversibly unfold in air. The obtained films were used for design of actuators, which are able to capture and release different objects through the reversible folding. PMID:24903283
Zhang, Yaoming; Ionov, Leonid
Film and Battery Tests.
The report presents results of tests on mechanical properties of biaxally oriented nylon film (Emblem) and Mylar film and on performance tests of lithium primary cells and silver-hydrogen secondary cells.
W. Stover
Film as Film; Understanding and Judging Movies.
The criteria for judging movies which are presented here are based on the belief that film criticism becomes rational, if not "objective", when it displays and inspects the nature of its evidence and the bases of its arguments. The author dissents from the view of early film theorists that montage is the essence of cinema, and that cinema is to be�
Perkins, V. F.
Marine Science Film Catalogue.
Forty-eight motion picture films and filmstrips in the field of marine science are catalogued in this booklet. Following the alphabetical index, one page is devoted to each film indicating its type, producer, recommended grade level, running time, and presence of color and/or sound. A summary of film content, possible uses, and outstanding�
Chapman, Frank L.
Licenses to Videotape Films
THE LAST SIX YEARS have marked a trend to convert 16mm films to video programs. The movement got its start with the introduction of efficient and moderately priced videotape recorders in the mid-1960s. The abun� dance of federal funds enabled many school districts to purchase video� tape recorders and film chains. (A film chain transmits the visual and sound images
Health Careers Film Guide.
This document, which represents a survey of the entire health career film field, was designed to provide information for people interested in a health career. The guide indicates that a major criteria for film selection was recency; however, some older films that give a fairly accurate image of a profession were included, with some emphasis given�
National Institutes of Health (DHEW), Bethesda, MD. Bureau of Health Manpower Education.
Focus on Shakespearean Films.
This is an anthology of reviews and critical pieces of the significant and available Shakespearean films made between 1935 and 1966. Included are three general essays on Shakespearean film by Ian Johnson, Henri Lemaitre, and Geoffrey Reeves. The specific films and their reviewers are: A Midsummer's Night Dream (1935) Allardyce Nicoll and Richard�
Eckert, Charles W., Ed.
Thick Film Interference.
Discusses why interference effects cannot be seen with a thick film, starting with a review of the origin of interference patterns in thin films. Considers properties of materials in films, properties of the light source, and the nature of light. (JN)
Trefil, James
Emotion elicitation using films
Researchers interested in emotion have long struggled with the problem of how to elicit emotional responses in the laboratory. In this article, we summarise five years of work to develop a set of films that reliably elicit each of eight emotional states (amusement, anger, contentment, disgust, fear, neutral, sadness, and surprise). After evaluating over 250 films, we showed selected film
James J. Gross; Robert W. Levenson
8MM Film Directory.
All 8mm films in general distribution in the United States, regardless of length or subject, are listed in this directory: Standard or Super 8, silent or sound, cartridge or reel-to-reel. Indexed alphabetically and by the Dewey Decimal System, films and film series are entered under the headings of Arts, Education, Fiction, Language, Recreation,�
Kone, Grace Ann, Comp.
iFilm was created to widen the availability and audience of films and filmed entertainment and to further the careers of their creators. It does this by placing an impressive selection of free and complete short films online in RealPlayer G2 format. Users may browse films by genre, location, category, or choose from the top ten lists of the most watched and most popular films. Viewer ratings and reviews are included for each film, and users are invited to add their own. iFilm recently unveiled the "first true debut of electronic cinema" by playing an original full-length feature film on May 3, and more are planned. Additional resources at the site include a Film News Channel, an internal search engine, and a free weekly email update service. Parents and teachers please note that some of the films contain adult themes. Users should also note that the films will only be viewable with a RealPlayer G2 player and that playback quality will vary significantly with connection speed.
Pyrolyzed thin film carbon
A method of making carbon thin films comprises depositing a catalyst on a substrate, depositing a hydrocarbon in contact with the catalyst and pyrolyzing the hydrocarbon. A method of controlling a carbon thin film density comprises etching a cavity into a substrate, depositing a hydrocarbon into the cavity, and pyrolyzing the hydrocarbon while in the cavity to form a carbon thin film. Controlling a carbon thin film density is achieved by changing the volume of the cavity. Methods of making carbon containing patterned structures are also provided. Carbon thin films and carbon containing patterned structures can be used in NEMS, MEMS, liquid chromatography, and sensor devices.
Tai, Yu-Chong (Inventor); Liger, Matthieu (Inventor); Harder, Theodore (Inventor); Konishi, Satoshi (Inventor); Miserendino, Scott (Inventor)
Electrically Conductive Polyimide Films
Semiconducting surfaces of SnO2 formed by curing polyamic acids containing tin complexes. Polyimide films made semiconductive via incorporation of semiconductive surface layers of SnO2. If SnO2-surfaced polyimide film used as free-standing film, then semiconductive layer protected by top coat of polyimide, deposited as film from solution directly onto SnO2. Resultant films flexible and resistant to both weather and high temperature. Used on aircraft to provide resistance to lightning strikes, and in microelectronics and flexible circuitry.
St. Clair, Anne K.; Ezzel, Stephen A.; Taylor, Larry T.; Boston, Harold G.
National Film Preservation Foundation
Created by the United States Congress, the National Film Preservation Foundation provides nationwide support to the preservation of American films of cultural and historical significance, along with improving film access for study, education, and exhibition. Located in San Francisco, the Foundation also awards grants to various film archives and preservations agencies who are also dedicated to preserving important landmarks in American cinematic history. Information on the site includes Preservation Basics, which talks about the importance of film preservation and the nature and chemistry of film decay. A grants and projects section offers information about applying for a film preservation grant from the Foundation and about ongoing preservation projects, like the Saving the Silents: The American Silent Fiction Film Project. In addition, the site contains a complete listing (by title, date, and archive) of the 500 films helped preserved by the Foundation. Film researchers and scholars will find a map of the United States that lists existing film archives and study centers around the country both helpful and a useful tool for determining the direction of their research.
Thermoelectric power and band spectrum transformation in Y1-xCaxBa2- xLaxCu3Oy
The superconducting and normal-state transport properties (resistivity ? and thermoelectric power S) of two sets of ceramic samples with composition Y1-xCaxBa2- xLaxCu3Oy (x = 0-0.4) have been investigated. The co-doping effect was studied at different conditions of the oxygen subsystem, namely, at a near-stoichiometric oxygen content and at that decreased by annealing in vacuum atmosphere. The thermoelectric power changes only slightly with increasing doping level, while the S(T) dependence acquires additional features, exhibiting a linear increase with decreasing temperature for heavily-doped samples and a rise in the S(T) curve slope as x grows. The results obtained are analysed in terms of a phenomenological narrow-band model that makes it possible to determine the band spectrum parameters in the normal state and to trace their changes with varying composition. In co-doped Y1-xCaxBa2- xLaxCu3Oy, impurities with valencies different from those of the native cations cancel out the influence of one another on the charge balance in the lattice. All the results obtained indicate that the normal-state and superconducting properties of the investigated system are mainly determined by this compensation effect. Comparison of the variation of the critical temperature Tc with the changing conduction bandwidth WD shows that there is a correlation between these parameters, according to which the superconducting properties of doped YBa2Cu3Oy depend strongly on the parameters of the band spectrum structure in the normal state. Analysis of how the conduction band is modified and S(T) transforms suggests that calcium is responsible for additional states in the conduction band.
Gasumyants, V. E.; Elizarova, M. V.; Patrina, I. B.
Documentary Elements in Early Films.
Focusing on documentary elements, this study examines the film content and film techniques of 681 motion pictures produced in the United States prior to 1904. Analysis of films by type, subject matter, and trends in subject matter shows that one-third of the early films are documentary in type and three-fourths of the films use subject matter of a�
Sanderson, Richard A.
Coating of plasma polymerized film
Plasma polymerized thin film coating and the use of other coatings is suggested for passivation film, thin film used for conducting light, and solid body lubrication film of dielectrics of ultra insulators for electrical conduction, electron accessories, etc. The special features of flow discharge development and the polymerized film growth mechanism are discussed.
Morita, S.; Ishibashi, S.
Film Study Course, Tenth Grade.
Part of a language arts program developed under an ESEA Title 3 grant, this curriculum guide for film study in the 10th grade is intended to help students (1) view films more critically, (2) understand the procedures of film making, and (3) appreciate the film as a work of art. Nine films are recommended for viewing, and sample lessons, including�
Ziegler, Fred H.; Schulz, H. James
Renaissance of the Film.
The post-World War II period was one of the liveliest in the history of the cinema. This is a collection of 33 critical articles on some of the best films of the perd. Most of the essays explicate the themes and symbols of the films. The essays deal with these films: "The Apu Trilogy,""L'Avventura,""Balthazar,""Blow-Up,""Bonnie and Clyde," Citizen�
Bellone, Julius, Ed.
Electrochemistry of fullerene films
The preparation of C60 films on electrodes by drop coating, Langmuir-Blodgett and electrochemical techniques, and the electrochemical behavior of these films in acetonitrile solutions containing a variety of supporting electrolytes (e.g., quaternary ammonium, alkali metal, and alkaline earth salts) is reviewed. Reduction can form insoluble films with incorporated cations or lead to dissolution. The large splitting between cathodic and anodic
Jerzy Chlistunoff; David Cliffel; Allen J. Bard
World's Smallest Film Festival
The World's Smallest Film Festival "is the first competitive showcase of digital video content for the new generation of mobile phones, PDAs, and other mobile devices." The event concluded at the Cellular Telecommunications and Internet Association Wireless conference in March 2003, but the films that were submitted to the festival can be viewed online. Running up to seven minutes in length, the films demonstrate the rapid advancements in mobile multimedia technology.
Dual Clearance Squeeze Film Damper.
A dual clearance hydrodynamic liquid squeeze film damper for a gas turbine engine is presented. Under normal operating conditions the device functions as a conventional squeeze film damper, using only one of its oil films. When an unbalance reaches abusiv...
D. P. Fleming
Microfilm--Which Film Type, Which Application?
Report on characteristics of different kinds of microfilm available indicates proper film for specific needs. Silver halide and nonsilver films, diazo film, vesicular film, reaction of films to light, effect of heat and humidity on films, film susceptibility to scratching, and potential longevity of film types are covered. (35 references) (EJS)
Dodson, Suzanne Cates
Preparation and Surface Analysis of a Fluorinated Amorphous Silicon for Photo-voltaic Device Application
Amorphous silicon films (a-Si:H) have been routinely deposited on a variety of substrates. Surface and interfacial studies were carried out with a PHI 5600 X-ray photo electron spectrometer. Co-deposition with fluorine yielded films having oxygen present as bulk oxide. The higher the fluorine content, the greater the amount of bulk oxygen observed. The presence of oxygen may be a contributing factor to inconsistent film properties of fluorine doped silicon materials, reported else where. A definite chemical interface between a layer containing fluorine and a layer made from pure silane has been delineated.
McWhinney, Hylton G.; Burton, Dawn; Fogarty, Thomas N.
Corporate sponsored image films
The vast number of high quality corporate image and advocacy films, combined with the many other instruments of persuasion and control by corporations, powerfully direct the attitudes of the populace. In the absence of equal access, the best protection against deception from any powerful institution is skepticism � minds trained in critical thinking. But technically proficient, expensive films (costing from
James R. Bennett
Epitaxial Iron Films.
The research program focused on the growth and the magnetic properties of epitaxial iron films grown on GaAs/InAs alloy substrates. Pseudomorphic growth of magnetic films on semiconductor substrates provides the potential for tuning of the magnetic proper...
E. D. Dahlberg P. I. Cohen
Thin Film Colorimetric Interferometry
Measurement technique for the study of very thin lubrication films down to one nanometer in a point contact between a steel ball and a transparent disc is used to explore the relationship between central and minimum film thickness and rolling speed at the interface between elastohydrodynamic and boundary lubrication for a series of lubricating fluids. This technique based on the
M. Hartl; I. Krupka; R. Poliscuk; M. Liska; J. Molimard; M. Querry; P. Vergne
Filming for Television.
Film makers, professional or amateur, will find in this volume an extensive discussion of the adaptation of film technique to television work, of the art of the camera operator, and of the productive relationships between people, organization, and hardware. Chapters include "The Beginnings," an overview of the interrelationship between roles in�
Englander, A. Arthur; Petzold, Paul
Stabilized chromium oxide film
Stabilized air-oxidized chromium films deposited on high-power klystron ceramic windows and sleeves having a thickness between 20 and 150.ANG. are useful in lowering secondary electron emission yield and in avoiding multipactoring and window failure due to overheating. The ceramic substrate for the film is chosen from alumina, sapphire or beryllium oxide.
Garwin, Edward L. (Los Altos, CA); Nyaiesh, Ali R. (Palo Alto, CA)
Stabilized air-oxidized chromium films deposited on high-power klystron ceramic windows and sleeves having a thickness between 20 and 150A are useful in lowering secondary electron emission yield and in avoiding multipactoring and window failure due to overheating. The ceramic substrate for the film is chosen from alumina, sapphire or beryllium oxide.
Nyaiesh, A.R.; Garwin, E.L.
Creative Film-Making.
The fundamentals of motion picture photography are introduced with a physiological explanation for the illusion of motion in a film. Film stock formats and emulsions, camera features, and lights are listed and described. Various techniques of exposure control are illustrated in terms of their effects. Photographing action with a stationary or a�
Smallman, Kirk
Thick film hydrogen sensor
A thick film hydrogen sensor element includes an essentially inert, electrically-insulating substrate having deposited thereon a thick film metallization forming at least two resistors. The metallization is a sintered composition of Pd and a sinterable binder such as glass frit. An essentially inert, electrically insulating, hydrogen impermeable passivation layer covers at least one of the resistors.
Hoffheins, Barbara S. (Knoxville, TN); Lauf, Robert J. (Oak Ridge, TN)
On Teaching Ethnographic Film
The author of this article, a developmental anthropologist, illustrates how the instructor can use ethnographic films to enhance the study of anthropology and override notions about the scope and efficacy of Western intervention in the Third World, provided the instructor places such films in their proper historical and cultural context. He�
Clarfield, Geoffrey
Insects On Film
A playful site dedicated to insects in films, with discussions of how the insects were portrayed in fiction as well as in documentaries. The site suffers a bit from having not been updated in the past few years, but there have been many good insect films to include.
Langmuir-Blodgett Films
The Langmuir trough enables high quality organic layers (Langmuir-Blodgett films) to be deposited onto a variety of substrates. This article describes the preparation and characterization of these monolayer and multilayer films and reviews many of their potential applications; these include two-dimensional magnetism, integrated and electro-optics, electron beam lithography, biological membranes, charge injection devices and field-effect transistors.
G. G. Roberts
Film Canister Farming
In this hands-on botany activity, learners sprout vegetables in film canisters. Learners grow nine seeds each of cabbage, radish, and parsley, experimenting with changing one variable (light, water, or temperature) to explore differences in the germination preferences of the plants. If film canisters aren't available, other small, opaque containers with lids can be substituted.
A thick film hydrogen sensor element includes an essentially inert, electrically-insulating substrate having deposited thereon a thick film metallization forming at least two resistors. The metallization is a sintered composition of Pd and a sinterable binder such as glass frit. An essentially inert, electrically insulating, hydrogen impermeable passivation layer covers at least one of the resistors. 8 figs.
Hoffheins, B.S.; Lauf, R.J.
Film Canister Science
Opaque film canisters are readily available, cheap, and useful for scientific inquiry in the classroom. They can also be surprisingly versatile and useful as a tool for stimulating scientific inquiry. In this article, the authors describe inquiry activities using film canisters for preservice teachers, including a "black box" activity and several�
Ferstl, Andrew; Schneider, Jamie L.
Thin-film forces in pseudoemulsion films
Use of foam for enhanced oil recovery (EOR) has shown recent success in steam-flooding field applications. Foam can also provide an effective barrier against gas coning in thin oil zones. Both of these applications stem from the unique mobility-control properties a stable foam possesses when it exists in porous media. Unfortunately, oil has a major destabilizing effect on foam. Therefore, it is important for EOR applications to understand how oil destroys foam. Studies all indicate that stabilization of the pseudoemulsion film is critical to maintain foam stability in the presence of oil. Hence, to aid in design of surfactant formulations for foam insensitivity to oil the authors pursue direct measurement of the thin-film or disjoining forces that stabilize pseudoemulsion films. Experimental procedures and preliminary results are described.
Bergeron, V.; Radke, C.J. [California Univ., Berkeley, CA (United States). Dept. of Chemical Engineering]|[Lawrence Berkeley Lab., CA (United States)
Part journal, part Internet salon, part discussion list, Film-Philosophy offers engaging and in-depth explorations of a wide variety of cinematic topics and lively email response and argument. Users can sign up to receive both the weekly review articles and discussion by email, or they may search and browse them at the site. The full text of all the articles from February 1997 to the present and discussion logs from February 1998 are available. In addition to articles from the current volume, the homepage lists calls for papers, film festivals, and related announcements. The site also features full-text book reviews, bibliographies, and links to journals, organizations, and sites about film philosophers (some broken links in the latter). Film-Philosophy is a terrific resource for film studies scholars and serious cinema fans.
Bright Lights Film Journal
Initially started as a print journal in 1974, online publication of Bright Lights Film Journal began in 1996, and continues to the present day. As noted on its site, the journal is "a popular-academic hybrid of movie analysis, history, and commentary, looking at classic and commercial, independent, exploitation, and international film from a wide range of vantage points from the aesthetic to the political." The journal is edited by Gary Morris, and contains pieces by a number of persons, including independent writers, film critics, and freelance journalists. While users can browse the archives dating back to 1996, the articles are also thematically organized on a sidebar on the homepage. These themes include Animation, Hong Kong films, Documentaries, and Film Noir. The interviews section is quite strong, and contains candid pieces with Frederico Fellini, Robert Wise, and John Woo.
Thermodynamics of liquid films and film tension measurements
This chapter provides a review of thermodynamics of liquid films. In particular, film thermodynamics based on the film excess convention is presented. Both the fundamental equation and mechanical equilibrium condition are similar to those of a surface phase in the well-known Gibbsian thermodynamics of surfaces. Experimental techniques for measuring film tension are also reviewed; in particular, Axisymmetric Drop Shape Analysis-Profile
P Chen; S. S Susnar; A. W Neumann
The National Film Registry: Acquiring Our Film Heritage.
The National Film Registry, which is primarily a designated list of films to be preserved by the Library of Congress, is also a valuable tool for selecting "films that are culturally, historically, and aesthetically significant." Following a brief discussion of the history and selection process of the National Film Registry, Southeast Missouri�
Ziegler, Roy A.
Application of YIG film to thin film inductors
The application of YIG (yttrium iron garnet) films to thin film inductors is examined up to 1 GHz. The application of a YIG film to thin film inductors made it possible to increase the inductance without increasing the stray capacitance. The sandwich-type YIG inductor exhibited an inductance 40 times larger than that of a similar air core inductor. The inductance
K. I. Arai; M. Yamaguchi; H. Ohzeki; M. Matsumoto
Chicago Film Archives
The Chicago Film Archives is an amazing regional film archive that collects, preserves, and provides access to films that represent the spirit of the Midwest. They work together with a range of other partners to host film festivals, develop seminars, and also sponsor public lectures. Visitors should click on over to the Explore Collections area to browse through over 600 films. This section contains finding aids, information about historic home movies, and access to very unique films. First-time visitors might start with some of the great home movies of Chicago in the 1950s and 1960s. Moving on, the Conservation Projects section is a real pip. Here, visitors can look over two remarkable dance performances from the Ravinia Music Festival from 1928 and seven short films that document the social and cultural upheavals that swept across Chicago in the late 1960s. It's a remarkable site where anyone with an interest in the history of documentary filmmaking and related matters will find much to enjoy.
Fluid film lubrication
The purpose of this book is to review the fundamentals of fluid lubricating films and to serve as a reference by applying these fundamentals to a variety of examples. Theory and anaysis are emphasized, and important equations, design fundamentals, and some design data are presented. Experimental results are introduced chiefly to corroborate the theory. Normalized notation is used whenever practical to stress the common characteristics of lubricating films and to simplify comparison. This presentation has the additional advantage of saving the reader the labor of confronting the wide range of terminology now in use. Tribology, the theory and practice of lubrication, is a broad subject, the exhaustive treatment of which would include thorough consideration both of the variety of mechanisms of lubrication and of bearing types. The treatment here is limited to those continuum fluid films, called simply ''films,'' which are associated with slider, journal, and sector thrust bearings. Considerable attention is given to incompressible films because films are often effectively incompressible. Thin film and boundary lubrication, the other important mechanisms of lubrication, are not examined here. There is a special focus upon gas lubrication.
Gross, W.A.; Matsch, L.A.; Castelli, V.; Eshel, A.; Vohr, J.H.; Wildmann, M.
Noncoherent Switching in Permalloy Films
High resolution Bitter pattern studies of the domain structure of permalloy films, with uniaxial anisotropy Hk and under the influence of applied fields in the film plane, are reported, and from these studies are inferred some aspects of noncoherent flux reversal processes. The threshold field for irreversible domain propagation across the film is measured for a variety of films differing
D. O. Smith; K. J. Harte
A Film Guide on China.
Over 80 films are listed in this annotated film guide on China. Designed to help educators select films about China, each entry contains a short annotation which gives a capsule and sometimes evaluative summary of film content. The booklet is divided into four sections on China before and after 1949, Taiwan, and Chinese culture. Each listing�
Wiley, Christopher J., Ed.
The Art of the Film.
The author prefaces his consideration of films as an art form with a discussion of the mechanics of filmmaking. He describes the division of talent on a movie set, details the history of the tools of filmmakers, and explains the production and reproduction of a film. The influence of film techniques on plot development in a fiction film is�
Lindgren, Ernest
Film and the Liberal Arts.
The essays in this book explore the relationship between films and some of the liberal arts. The first set of essays revolves around the topic of films and rhetoric. They describe the special language of films and its unique mode of communication. A second group of essays deals with films and literature and includes discussions on writing for�
Ross, T. J.
Aging in Thin Metallic Films.
Low magnetostriction NiFe and NiFe based ternary films 220A and 340A thick were prepared by thermal evaporation and bias sputtering. A few evaporated films were sputter etched. The films were aged in air with a magnetic bias in the plane of the film and p...
H. R. Irons W. E. Anderson L. J. Schwee
Thin-film photovoltaics
CdTe and CuIn1-xGaxSe2-ySy (CIGSS) are ideal candidates for thin-film solar cells. Present photovoltaic (PV) conversion efficiencies of champion thin-film solar cells are: CuIn1-xGaxSe2 (CIGS) 19.5%, CdTe 16.5%, and a-Si:H 12.4%. Thin-film PV modules could spearhead production growth of photovoltaics in the United States because of their added production capacity. For this purpose, module efficiencies must be improved to the 13%-15%
Neelkanth G. Dhere; Ramesh G. Dhere
Ultrahard carbon nanocomposite films
Modest thermal annealing to 600 C of diamondlike amorphous-carbon (a-C) films grown at room temperature results in the formation of carbon nanocomposites with hardness similar to diamond. These nanocomposite films consist of nanometer-sized regions of high density a-C embedded in an a-C matrix with a reduced density of 5--10%. The authors report on the evolution of density and bonding topologies as a function of annealing temperature. Despite a decrease in density, film hardness actually increases {approximately} 15% due to the development of the nanocomposite structure.
Negative birefringent polyimide films
A negative birefringent film, useful in liquid crystal displays, and a method for controlling the negative birefringence of a polyimide film is disclosed which allows the matching of an application to a targeted amount of birefringence by controlling the degree of in-plane orientation of the polyimide by the selection of functional groups within both the diamine and dianhydride segments of the polyimide which affect the polyimide backbone chain rigidity, linearity, and symmetry. The higher the rigidity, linearity and symmetry of the polyimide backbone, the larger the value of the negative birefringence of the polyimide film.
Harris, Frank W. (Inventor); Cheng, Stephen Z. D. (Inventor)
Thin-film optical initiator
A thin-film optical initiator having an inert, transparent substrate, a reactive thin film, which can be either an explosive or a pyrotechnic, and a reflective thin film. The resultant thin-film optical initiator system also comprises a fiber-optic cable connected to a low-energy laser source, an output charge, and an initiator housing. The reactive thin film, which may contain very thin
Kenneth L
Shear cutting of PET film
Poly (ethylene terephthalate) (PET) film was extruded and then successively biaxially stretched and thermofixed to obtain\\u000a a high-strength film with stable dimensions. Next, the film was shear cut by two rotating circular knives. In the first part\\u000a of this paper, a microscopic evaluation of the sheared edges of films, cut under a variety of parameters, i.e. cutting speed,\\u000a film thickness
D. Bollen; J. Deneir; E. Aernoudt; W. Muylle
Laser beam recorder on film
Aerial image recorders used in aerial reconnaissance are examined. The recorders are capable of : (1) driving the film at a speed monitored by an outside signal, (2) printing the films line by line, (3) continouosly developing the printed film, and (4) extracting the film for examination by a photointerpreter. The spot line scanning system, and monitoring of the position of printed points and image dynamics are described. The film developing process is analyzed.
Petit, J. L.
Thick Film Glasses.
The technicA1 literature was reviewed in order to characterize the thermal expansion, viscosity, surface tension and wetting behavior as functions of composition for glasses of present or potential use in thick film formulations. The applicability of the ...
R. W. Vest
Magnetron sputtered boron films
A method is described for the production of thin boron and titanium/boron films by magnetron sputter deposition. The amorphous boron films contain no morphological growth features, unlike those found when thin films are prepared by various physical vapor deposition processes. Magnetron sputter deposition method requires the use of a high density crystalline boron sputter target which is prepared by hot isostatic pressing. Thin boron films prepared by this method are useful for producing hardened surfaces, surfacing machine tools, etc. and for ultra-thin band pass filters as well as the low Z element in low Z/high Z optical components, such as mirrors which enhance reflectivity from grazing to normal incidence. 8 figs.
Makowiecki, D.M.; Jankowski, A.F.
Film Noir Foundation
Whether you're a fan of the Fred McMurray vehicle "Double Indemnity" or Ricardo Montalban's turn as a detective in "Mystery Street", lovers of film noir will find much to admire on the Film Noir Foundation website. The Film Noir Foundation was created to serve as an "educational resource regarding the cultural, historical, and artistic significance of film noir as an original American cinematic movement." The materials on the site are divided into nine sections, including "Video Archives", "NoirCity", and "News". The "Video Archives" are fantastic with interviews that include June Lockhart, Harry Belafonte, and a riotous performance by Ernest Borgnine. Moving along, the "Resources" area includes audio clips of Bob Dylan talking about his own noir literary inspirations and an interview with Robert Mitchum about his own poetry. Finally, visitors can chime in with their own thoughts in the "Forum" and also make a donation to the Foundation.
Alternate film dielectric materials.
This paper presents data on polymeric dielectric films evaluated to support the design of high-energy-density capacitors. Evaluated materials include polycarbonate (two sources), polyphenylene sulfide, polyvinylidene fluoride, polyethermide (three sources...
J. C. Foster J. O. Harris J. I. Martinez
Amorphous diamond films
Amorphous diamond films having a significant reduction in intrinsic stress are prepared by biasing a substrate to be coated and depositing carbon ions thereon under controlled temperature conditions. 1 fig.
Falabella, S.
Thin Film Growth
This is a PDF version of lecture slides that discuss thin film growth processes. Slide topics include plasma properties, DC glow discharge, ionization, plasma species, magnetrons, collisions, and chemical reactions. Numerous charts and mathematical formulas are presented.
Rack, Philip D.
Heterogeneity in Polymer Thin Films
In the last two decades very extensive studies have been performed on polymer thin films to reveal very interesting but unusual properties. One of the most interesting findings is the decrease in glass transition temperature Tg with film thickness in polystyrene (PS) thin film supported on Si substrate. Another interesting finding is apparent negative thermal expansivity in glassy state for thin films below ~25 nm. In order to understand the unusual properties of polymer thin films we have studied temperature dependence of thickness of polystyrene thin films by means of X-ray and neutron reflectivity. In addition, we also studied dynamics of PS thin films using inelastic neutron scattering. In the presentation we will discuss the results from viewpoints of heterogeneity of polymer thin films. Finally we did neutron reflectivity measurements on a 5-layer thin film, consisting of alternatively stacked d-PS and h-PS layers to see the distribution of glass transition temperature and thermal expansivity directly.
Kanaya, Toshiji; Inoue, Rintaro; Nishida, Koji
Virus-PEDOT Biocomposite Films
Virus-poly(3,4-ethylenedioxythiophene) (virus-PEDOT) biocomposite films are prepared by electropolymerizing 3,4-ethylenedioxythiophene (EDOT) in aqueous electrolytes containing 12 mM LiClO4 and the bacteriophage M13. The concentration of virus in these solutions, [virus]soln, is varied from 3 nM to 15 nM. A quartz crystal microbalance is used to directly measure the total mass of the biocomposite film during its electrodeposition. In combination with a measurement of the electrodeposition charge, the mass of the virus incorporated into the film is calculated. These data show that concentration of the M13 within the electropolymerized film, [virus]film, increases linearly with [virus]soln. The incorporation of virus particles into the PEDOT film from solution is efficient, resulting in a concentration ratio: [virus]film:[virus]soln ?450. Virus incorporation into the PEDOT causes roughening of the film topography that is observed using scanning electron microscopy and atomic force microscopy (AFM). The electrical conductivity of the virus-PEDOT film, measured perpendicular to the plane of the film using conductive tip AFM, decreases linearly with virus loading, from 270 ?S/cm for pure PE-DOT films to 50 ?S/cm for films containing 100 ?M virus. The presence on the virus surface of displayed affinity peptides did not significantly influence the efficiency of incorporation into virus-PEDOT biocomposite films.
Donavan, Keith C.; Arter, Jessica A.
Dewetting of Thin Polymer Films
DEWETTING OF THIN POLYMER FILMS P. S. Dixit,(1) J. L. Sorensen,(2) M. Kent,(2) H. S. Jeon*(1) (1) Department of Petroleum and Chemical Engineering, New Mexico Institute of Mining and Technology, 801 Leroy Place, Socorro, NM 87801, firstname.lastname@example.com (2) Department 1832, Sandia National Laboratories, Albuquerque, NM. Dewetting of thin polymer films is of technological importance for a variety of applications such as protective coatings, dielectric layers, and adhesives. Stable and smooth films are required for the above applications. Above the glass transition temperature (Tg) the instability of polymer thin films on a nonwettable substrate can be occurred. The dewetting mechanism and structure of polypropylene (Tg = -20 ^circC) and polystyrene (Tg = 100 ^circC) thin films is investigated as a function of film thickness (25 �h < 250 �and quenching temperature. Contact angle measurements are used in conjunction with optical microscope to check the surface homogeneity of the films. Uniform thin films are prepared by spin casting the polymer solutions onto silicon substrates with different contact angles. We found that the stable and unstable regions of the thin films as a function of the film thickness and quenching temperature, and then constructed a stability diagram for the dewetting of thin polymer films. We also found that the dewetting patterns of the thin films are affected substantially by the changes of film thickness and quenching temperature.
Dixit, P. S.; Sorensen, J. L.; Kent, M.; Jeon, H. S.
Depositing Adherent Ag Films On Ti Films On Alumina
Report discusses cleaning of ceramic (principally, alumina) substrates in preparation for sputter deposition of titanium intermediate films on substrates followed by sputter deposition of outer silver films. Principal intended application, substrates sliding parts in advanced high-temperature heat engines, and outer silver films serve as solid lubricants: lubricating properties described in "Solid Lubricant for Alumina" (LEW-15495).
Honecy, Frank S.
Screen Printed PZT Thick Films Using Composite Film Technology
A spin coating composite sol gel technique for producing lead zirconate titanate (PZT) thick films has been modified for use with screen printing techniques. The resulting screen printing technique can be used to produce 10 ?m thick films in a single print. The resultant films are porous but the density can be increased through the use of repeated sol infiltration\\/pyrolysis
R. A. Dorey; R. W. Whatmore; S. P. Beeby; R. N. Torah; N. M. White
The New Film Technologies: Computerized Video-Assisted Film Production.
Over the past few years, video technology has been used to assist film directors after they have shot a scene, to control costs, and to create special effects, especially computer assisted graphics. At present, a computer based editing system called "Film 5" combines computer technology and video tape with film to save as much as 50% of the cost�
Mott, Donald R.
The Nuclear Debate in Film
Provides a nuclear film bibliography grouped into the areas of: building and using the bomb; living with the bomb; and living with nuclear power. These films are for mature high school students and older. (MLH)
Dowling, John
Starch-Based Semipermeable Films.
While cellulose-based films have achieved prominence as semipermeable membranes, starch-based films have not been available that would withstand prolonged exposure to water. Starch and cellulose are high polymers composed of D-glucose units. Starch readil...
F. H. Otey R. P. Westhoff
Growth Facility for Nanocomposite Films.
Two facilities were constructed for synthesis of protective thin films. The first system utilized the recently developed Laser Absorption Wave Deposition (LAWD) technique. With this technique multiple layers of ultrahard carbon films can be grown directly...
H. W. White
Science and Science Fiction Films.
Describes an undergraduate physics course for nonscience majors which combines physics with science fiction films. Includes course format, sample module on the concept of momentum, and an appendix with a listing of science fiction films used in this course. (DS)
Dubeck, Leroy W.
Foundation for Film and Science
Provides a comprehensive discussion on the Stichting Film en Wetenschap, SFW (Foundation for Film and Science), in Utrecht. Various aspects of the use of audio-visual aids in university teaching are looked at in detail. (Editor/RK)
van der Veen, G.
Thin film photovoltaics
Thin films are considered a potentially attractive technological approach to making cost-effective electricity by photovoltaics. Over the last twenty years, many have been investigated and some (cadmium telluride, copper indium diselenide, amorphous silicon) have become leading candidates for future large-scale commercialization. This paper surveys the past development of these key thin films and gives their status and future prospects. In all cases, significant progress toward cost-effective PV electricity has been made. If this progress continues, it appears that thin film PV could provide electricity that is competitive for summer daytime peaking power requirements by the middle of the 1990s; and electricity in a range that is competitive with fossil fuel costs (i.e., 6 cents/kilowatt-hour) should be available from PV around the turn of the century. 22 refs., 9 figs.
Zweibel, K.; Ullal, H.S.
Thin film temperature sensor
Thin film surface temperature sensors were developed. The sensors were made of platinum-platinum/10 percent rhodium thermocouples with associated thin film-to-lead wire connections and sputtered on aluminum oxide coated simulated turbine blades for testing. Tests included exposure to vibration, low velocity hydrocarbon hot gas flow to 1250 K, and furnace calibrations. Thermal electromotive force was typically two percent below standard type S thermocouples. Mean time to failure was 42 hours at a hot gas flow temperature of 1250 K and an average of 15 cycles to room temperature. Failures were mainly due to separation of the platinum thin film from the aluminum oxide surface. Several techniques to improve the adhesion of the platinum are discussed.
Grant, H. P.; Przybyszewski, J. S.
Alternate film dielectric materials
This paper presents data on polymeric dielectric films evaluated to support the design of high-energy-density capacitors. Evaluated materials include polycarbonate (two sources), polyphenylene sulfide, polyvinylidene fluoride, polyethermide (three sources), polyimide (four sources), polyethersulfone, and polyetherether ketone. A polyester was evaluated as the control material since many of our prior designs utilized this dielectric. The film evaluations were based on dielectric constant and dissipation factor variation as a function of temperature from {minus}55{degree}C to 300{degree}C, as well as dielectric breakdown strength. Additionally, film/foil capacitors in a dry, wrap-and-fill configuration were fabricated and tested to determine insulation resistance, breakdown voltage, and radiation hardness. Results will be presented for all the evaluations based on the several criteria. 7 refs., 4 figs., 4 tabs.
Foster, J.C. (General Electric Co., Largo, FL (USA). Neutron Devices Dept.); Harris, J.O.; Martinez, J.I. (Sandia National Labs., Albuquerque, NM (USA))
Film Literature Index
This very ambitious project from Indiana University was funded by the National Endowment for the Humanities, and it continues to be updated on a regular basis. The Film Literature Index (FLI) annually indexes 150 film and television periodicals from 30 countries in their entirety, along with 200 other periodicals selectively for articles on film and television. The FLI database can be searched by subject headings, names, production titles, or by corporate names. Visitors can browse around, or perform advanced searches as their needs require. More information about the project can be found in the "About FLI" section, which can be accessed at the top of the homepage. Here visitors can learn about the history of the FLI, and also read about various papers and presentations that document the creation of the FLI Online site.
NMR characterization of thin films
A method, apparatus, and system for characterizing thin film materials. The method, apparatus, and system includes a container for receiving a starting material, applying a gravitational force, a magnetic force, and an electric force or combinations thereof to at least the starting material, forming a thin film material, sensing an NMR signal from the thin film material and analyzing the NMR signal to characterize the thin film of material.
Gerald, II, Rex E. (Brookfield, IL); Klingler, Robert J. (Glenview, IL); Rathke, Jerome W. (Homer Glen, IL); Diaz, Rocio (Chicago, IL); Vukovic, Lela (Westchester, IL)
Dual clearance squeeze film damper
A dual clearance hydrodynamic liquid squeeze film damper for a gas turbine engine is described. Under normal operating conditions, the device functions as a conventional squeeze film damper, using only one of its oil films. When an unbalance reaches abusive levels, as may occur with a blade loss or foreign object damage, a second, larger clearance film becomes active, controlling vibration amplitudes in a near optimum manner until the engine can be safely shut down and repaired.
Fleming, D. P. (inventor)
Thin film ceramic thermocouples
A thin film ceramic thermocouple (10) having two ceramic thermocouple (12, 14) that are in contact with each other in at least on point to form a junction, and wherein each element was prepared in a different oxygen/nitrogen/argon plasma. Since each element is prepared under different plasma conditions, they have different electrical conductivity and different charge carrier concentration. The thin film thermocouple (10) can be transparent. A versatile ceramic sensor system having an RTD heat flux sensor can be combined with a thermocouple and a strain sensor to yield a multifunctional ceramic sensor array. The transparent ceramic temperature sensor that could ultimately be used for calibration of optical sensors.
Gregory, Otto (Inventor); Fralick, Gustave (Inventor); Wrbanek, John (Inventor); You, Tao (Inventor)
Thin film photovoltaic device
A thin film photovoltaic solar cell which utilizes a zinc phosphide semiconductor is of the homojunction type comprising an n-type conductivity region forming an electrical junction with a p-type region, both regions consisting essentially of the same semiconductor material. The n-type region is formed by treating zinc phosphide with an extrinsic dopant such as magnesium. The semiconductor is formed on a multilayer substrate which acts as an opaque contact. Various transparent contacts may be used, including a thin metal film of the same chemical composition as the n-type dopant or conductive oxides or metal grids.
Catalano, Anthony W. (Wilmington, DE); Bhushan, Manjul (Wilmington, DE)
A thin film photovoltaic solar cell which utilizes a zinc phosphide semiconductor is of the homojunction type comprising an n-type conductivity region forming an electrical junction with a p-type region, both regions consisting essentially of the same semiconductor material. The n-type region is formed by treating zinc phosphide with an extrinsic dopant such as magnesium. The semiconductor is formed on a multilayer substrate which acts as an opaque contact. Various transparent contacts may be used, including a thin metal film of the same chemical composition as the n-type dopant or conductive oxides or metal grids. 5 figs.
Catalano, A.W.; Bhushan, M.
Sign Language Film List
In learning any language, a good way to hone your listening skills to range of common speakers is by watching movies in the language, and sign language is no exception. Although referring to it as using your listening skills may be a bit of a stretch, viewing different people sign can be good real-life practice in order to learn the nuisances of individuals' "speech." The Sign Language Film List has attempted to compile a complete of a list of films and other works available in American Sign Language, and their efforts should be rewarding to students, speakers and instructors.
Lubotsky, John
RIS Minus PACS Equals Film
Web-based integration methods can be used to resolve a fundamental issue in the transition from film to a picture archiving and communication system (PACS): the identification of relevant prior studies only available on film. Even in the most ambitious conversions from a film-based environment to PACS, there are issues regarding prior studies not on PACS. Failure to compare with prior
Wyatt M. Tellis; Katherine P. Andriole; Christopher S. Jovais; David E. Avrin
Optical Response of Graded Films
Graded materials have quite different physical properties from the homogeneous materials. Recently, it has been found that graded thin films may have better dielectric properties than a single-layer film. The materials properties of graded films can vary continuously in space. These materials have attracted much interest in various engineering applications. However, the traditional theories fail to deal with the composites
Joseph T. A. Kwok
Working in the Film Archives.
In order to locate and study the primary sources needed in film research, a combination of bibliographies, advice from experienced research workers, and scripts, pressbook files, and film-print collections must be used. This discussion provides suggestions for locating and using archival film materials and examines some of the standard references�
Aig, Dennis
Coated Aluminized Film Resists Corrosion
Commercially available corrosion-protection coating allows less costly metals - aluminum in particular used in heat-reflecting films for thermal barriers. Previously, such films had to incorporate gold as reflective layer to withstand humidity, moisture, and salt spray without corroding. This protective coating prevents corrosion of metalized films during evironmental exposure yet remains flexible, thermally stable and clear.
Rockoff, H. J.
Ferroelectricity in ultrathin perovskite films
Understanding the suppression of ferroelectricity in perovskite thin films is a fundamental issue that has remained unresolved for decades. We report a synchrotron x-ray study of lead titanate as a function of temperature and film thickness for films as thin as a single unit cell. At room temperature, the ferroelectric phase is stable for thicknesses down to 3 unit cells
Dillon D. Fong; G. Brian Stephenson; Stephen K. Streiffer; Jeffrey A. Eastman; Orlando Auciello; Paul H. Fuoss; Carol Thompson
Thermotropic Liquid Crystal Film Underwater
A thermotropic liquid crystal film was produced in distilled water successfully. A lecithin suspension was utilized to make the film. Polarizing microscopic observations were carried out. The molecular arrangement was seemed to be homeotoropic. An expected electrooptic response of the film underwater was confirmed.
Uto, Sadahito; Nakanishi, Yuuji; Matsumoto, Takahumi
Ferroelectric Langmuir-Blodgett films
The ferroelectric Langmuir-Blodgett films are prepared and investigated for the first time The films are prepared from the ferroelectric copolymer of vinylidene fluoride with trifluorethylene The films with the thickness off 150 � show the pyroelectric effect being measured along the polar C-axis perpendicular to the substrate surface, partial remnant polarization switching and ferroelectric phase transition of the first order,
S. Palto; L. Blinov; A. Bune; E. Dubovik; V. Fridkin; N. Petukhova; K. Verkhovskaya; S. Yudin
Ferroelectric langmuir-blodgett films
Ferroelectric Langmuir-Blodgett films are prepared and investigated for the first time. The films are prepared from the ferroelectric copolymer of vinylidene fluoride with trifluorethylene. Films with a thickness of 150� show a pyroelectric effect, remnant polarization switching and a ferroelectric phase transition of the first order, characterized by temperature hysteresis.
Automatic recognition of film genres
Film genres in digital video can be detected automatically. In a three-step approach we analyze first the syntactic properties of digital films: color statistics, cut detection, camera motion, object motion and audio. In a second step we use these statistics to derive at a more abstract level film style attributes such as camera panning and zooming, speech and music. These
Stephan Fischer; Rainer Lienhart; Wolfgang Effelsberg
Longevity Of Dry Film Lubricants
Report describes evaluation of dry film lubricants candidate for use in rotary joints of proposed Space Station. Study included experiments and theoretical analyses focused on longevity of sputtered molybdenum disulfide films and ion-plated lead films under conditions partially simulating rolling contact.
Kannel, J. W.; Stockwell, R. D.
Film Analysis through Linguistic Base
Studies made in the last few years show that using films in language classrooms is an effective way in teaching a foreign language. Well-chosen films can serve as a valuable pedagogical aid, both for classroom use and self-study. This article is about using films in language classrooms through a specially designed course, whose outline description�
Tanriverdi, Belgin
Making Diamondlike Films More Transparent
Diamondlike carbon films highly transparent to visible light made by dual-ion-beam deposition process. Hard, resistant to scratching, and hermetic. Used as protective coatings on eyeglasses, magnetic recording heads, computer hard disks, and windows in bar-code scanners. Amorphous diamondlike carbon films preferable to polycrystalline diamond films in these and other applications. Smooth and adherent and deposited at room temperature.
Mirtich, Michael J.; Kussmaul, Michael T.; Sovey, James S.; Banks, Bruce A.
Films in Depth.
Bound in a slipcover rather than in signatures, this "book" is made up of thirteen separately bound booklets. The first booklet is an introduction to the use of film in the classroom both in teaching the filmic art and in increasing the visual literacy of students on the high school and early college levels. The twelve other booklets each treat a�
Schrievogel, Paul A.; Prete, Anthony T.
Exploring Materials: Thin Films
In this activity, learners create a colorful bookmark using a super thin layer of nail polish on water. Learners discover that a thin film creates iridescent, rainbow colors. This is a very fun and engaging activity for learners, and a great way to talk about how nanoscale structures often affect a materials' properties. SAFETY: Do this activity in a well-ventilated area.
Network, Nanoscale I.; Sciencenter
Introduction to Film.
There are numerous ways to structure the introduction to film course so as to meet the needs of the different types of students who typically enroll. Assuming there is no production component in the course, the teacher is left with two major approaches to choose from--historical and aesthetic. The units in the course will typically be built around�
Burns, Gary
Evaluation of PE Film.
Laboratory tests were conducted to assess the ability of a 3-mil thick adhesive-backed polyethylene film (Polymask) to protect vehicle paint finishes from acid-rain damage. The laboratory tests employed conditions known to be relevant to actual service co...
J. E. Funk T. Hopwood C. M. Oberst
Electroluminescent film display device
During the reporting period, progress in fabricating 6 in. x 6 in. thin film transistor (TFT) display circuits was slowed due to equipment failure. These problems were largely overcome. A technique was devised, and demonstrated, for making good edge connections to the array using evaporated metal fingers. Considerable efforts was devoted to constructing an alternative vacuum deposition system, with alignment
T. P. Brody; W. S. Escott; W. Lehmann; D. H. Davies
Cross-Examining Film
The Supreme Court decision in Scott v. Harris holds that a Georgia police officer did not violate a fleeing suspect's Fourth Amendment rights when he caused the suspect's car to crash. The court's decision relies almost entirely on the filmed version of the high-speed police chase taken from a \\
Jessica M Silbey
Thin Film Microstrip Circuits.
A four layer thin film metallization system is comprised of layers of tantalum, chromium, copper and gold and is useful in high resolution, low loss microstrip circuits. The metallization system is compatible with lead-tin solder and, in addition, provide...
R. D. Hall
Soldering to gold films
Reliable solder joints can be made on gold metallised microcircuits using lead-indium solders providing certain important\\u000a conditions are understood and carefully controlled. This paper reviews the three fundamental concepts of scavenging, wetting,\\u000a and ageing, which are relevant when soldering to gold films.
Frederick G. Yost
Teaching Nutrition with Films.
Pretests and posttests were administered to students to determine if the "Mulligan Stew" film series on nutrition was effective with grades 2-3 as well as grades 4-6 from a rural population. A significant increase in knowledge was found in all grades, and the knowledge was retained for six months. (CT)
Williams, Virginia H.; And Others
Soap Films and Bubbles.
Develops and explains a format for a workshop which focuses on soap films and bubbles. The plan consists of: a discussion to uncover what children know about bubbles; explanations of the demonstration equipment; the presentation itself; the assembly of the workshop kit; and time to play with the bubbles. (ML)
Rice, Karen
Film: The Creative Eye.
Short films are often experimental in nature. They can place aspects of the environment which are usually unnoticed in such a way as to sharpen our observations of the world, and "create a new awareness, a fuller sense of life and being." Based on the premise that visual literacy is becoming increasingly important, this book describes several�
Sohn, David A.
Film as Composition.
Describes the development of a freshman English program based on the analogy of film as composition and discusses implications of this program for other teachers of writing at a time when television and movies are giving unprecedented competition to the printed page for students' attention. (HTH)
Costanzo, William
A scanning device for use as a film analyzer is described. The machine ; was originally developed to analyze oscilloscope pictures, but other types of ; pictures such as spark chamber pictures are proposed for analysis. The device ; differs from other scanning machines in that the cathode ray spot is obliged to ; follow the picture of the trace
Orientation filtering for crystalline films
A substrate is coated with a film to be recrystallized. A pattern of crystallization barriers is created in the film, for example, by etching voids in the film. An encapsulation layer is generally applied to protect the film, fill the voids and otherwise enhance a recrystallization process. Recrystallization is carried out such that certain orientations pass preferentially through the barrier, generally as a result of growth-velocity anisotropy. The result is a film of a specific predetermined crystallographic orientation, a range of orientations or a set of discrete orientations.
Smith, Henry I. (Sudbury, MA) [Sudbury, MA; Atwater, Harry A. (Somerville, MA) [Somerville, MA; Thompson, Carl V. (Watertown, MA) [Watertown, MA; Geis, Michael W. (Acton, MA) [Acton, MA
Colorless, Transparent, Aromatic Polyimide Films
New process yields aromatic condensation polyimide films essentially colorless. Films between 90- and 100-percent transparent at visible wavelength of 500 nm. Optically transparent polyimide films made from variety of aromatic condensation polyimides. Range from very pale in color to colorless, compared to bright yellow color of conventional/ commercial aromatic polyimide film. Increased transparency achieved at no sacrifice in thermal stability, flexibility, toughness, or mechanical properties. These features extremely attractive as films or coating materials for aerospace applications or for any other applications where high optical transparency or thermal stability is required.
St. Clair, A. K.; St. Clair, T. L.; Ezzell, K. S.; Ely, R. M.
Process to form mesostructured films
This invention comprises a method to form a family of supported films film with pore size in the approximate range 0.8-20 nm exhibiting highly ordered microstructures and porosity derived from an ordered micellar or liquid-crystalline organic-inorganic precursor structure that forms during film deposition. Optically transparent, 100-500-nm thick films exhibiting a unique range of microstructures and uni-modal pore sizes are formed in seconds in a continuous coating operation. Applications of these films include sensors, membranes, low dielectric constant interlayers, anti-reflective coatings, and optical hosts.
Brinker, C. Jeffrey (Albuquerque, NM); Anderson, Mark T. (Woodbury, MN); Ganguli, Rahul (Camarillo, CA); Lu, Yunfeng (Albuquerque, NM)
A thin-film optical initiator having an inert, transparent substrate, a reactive thin film, which can be either an explosive or a pyrotechnic, and a reflective thin film. The resultant thin-film optical initiator system also comprises a fiber-optic cable connected to a low-energy laser source, an output charge, and an initiator housing. The reactive thin film, which may contain very thin embedded layers or be a co-deposit of a light-absorbing material such as carbon, absorbs the incident laser light, is volumetrically heated, and explodes against the output charge, imparting about 5 to 20 times more energy than in the incident laser pulse.
Erickson, Kenneth L. (Albuquerque, NM)
Combustion effects on film cooling
The effects of: (1) a reactive environment on film cooling effectiveness, and (2) film cooling on rocket engine performance were determined experimentally in a rocket thrust chamber assembly operating with hydrogen and oxygen propellants at 300 psi chamber pressure. Tests were conducted using hydrogen, helium, and nitrogen film coolants in an instrumented, thin walled, steel thrust chamber. The film cooling, performance loss, and heat transfer coefficient data were correlated with the ALRC entrainment film cooling model which relates film coolant effectiveness and mixture ratio at the wall to the amount of mainstream gases entrained with the film coolant in a mixing layer. In addition, a comprehensive thermal analysis computer program, HOCOOL, was prepared from previously existing ALRC computer programs and analytical techniques.
Historical Nuclear Weapons Test Films
This site is the product of a recent joint effort between the US Department of Energy and Department of Defense to declassify films on the nuclear weapons program, place them on videotape, and make them publicly available. Taken as a whole, the films document the history of nuclear weapon development in the US, beginning with the first bomb tested at Trinity Site in southeastern New Mexico in July 1945. As the site notes, while portions of these films were previously released, this is the first time the films have ever been edited for declassification and public release. The films are grouped in five sections, with listings giving operation name date, length of film, and format (color or black and white). Clicking on an individual entry for a film brings up a two-paragraph description and short clips in .mpeg and RealPlayer format, the latter offering four connection speed choices. Video purchase information is provided at the site.
Thin film superconductor magnetic bearings
A superconductor magnetic bearing includes a shaft (10) that is subject to a load (L) and rotatable around an axis of rotation, a magnet (12) mounted to the shaft, and a stator (14) in proximity to the shaft. The stator (14) has a superconductor thin film assembly (16) positioned to interact with the magnet (12) to produce a levitation force on the shaft (10) that supports the load (L). The thin film assembly (16) includes at least two superconductor thin films (18) and at least one substrate (20). Each thin film (18) is positioned on a substrate (20) and all the thin films are positioned such that an applied magnetic field from the magnet (12) passes through all the thin films. A similar bearing in which the thin film assembly (16) is mounted on the shaft (10) and the magnet (12) is part of the stator (14) also can be constructed.
Weinberger, Bernard R. (Avon, CT)
Thin film mechanics
This doctoral thesis details the methods of determining mechanical properties of two classes of novel thin films suspended two-dimensional crystals and electron beam irradiated microfilms of polydimethylsiloxane (PDMS). Thin films are used in a variety of surface coatings to alter the opto-electronic properties or increase the wear or corrosion resistance and are ideal for micro- and nanoelectromechanical system fabrication. One of the challenges in fabricating thin films is the introduction of strains which can arise due to application techniques, geometrical conformation, or other spurious conditions. Chapters 2-4 focus on two dimensional materials. This is the intrinsic limit of thin films-being constrained to one atomic or molecular unit of thickness. These materials have mechanical, electrical, and optical properties ideal for micro- and nanoelectromechanical systems with truly novel device functionality. As such, the breadth of applications that can benefit from a treatise on two dimensional film mechanics is reason enough for exploration. This study explores the anomylously high strength of two dimensional materials. Furthermore, this work also aims to bridge four main gaps in the understanding of material science: bridging the gap between ab initio calculations and finite element analysis, bridging the gap between ab initio calculations and experimental results, nanoscale to microscale, and microscale to mesoscale. A nonlinear elasticity model is used to determine the necessary elastic constants to define the strain-energy density function for finite strain. Then, ab initio calculations-density functional theory-is used to calculate the nonlinear elastic response. Chapter 2 focuses on validating this methodology with atomic force microscope nanoindentation on molybdenum disulfide. Chapter 3 explores the convergence criteria of three density functional theory solvers to further verify the numerical calculations. Chapter 4 then uses this model to investigate the role of grain boundaries on the strength of chemical vapor deposited graphene. The results from these studies suggest that two dimensional films have remarkably high strength-reaching the intrinsic limit of molecular bonds. Chapter 5 explores the viscoelastic properties of heterogeneous polydimethylsiloxane (PDMS) microfilms through dynamic nanoindentation. PDMS microfilms are irradiated with an electron beam creating a 3 m-thick film with an increased cross-link density. The change in mechanical properties of PDMS due to thermal history and accelerator have been explored by a variety of tests, but the effect of electron beam irradiation is still unknown. The resulting structure is a stiff microfilm embedded in a soft rubber with some transformational strain induced by the cross-linking volume changes. Chapter 5 employs a combination of dynamic nanoindentation and finite element analysis to determine the change in stiffness as a function of electron beam irradiation. The experimental results are compared to the literature. The results of these experimental and numerical techniques provide exciting opportu- nities in future research. Two dimensional materials and flexible thin films are exciting materials for novel applications with new form factors, such as flexible electronics and microfluidic devices. The results herein indicate that you can accurately model the strength of two dimsensional materials and that these materials are robust against nanoscale defects. The results also reveal local variation of mechanical properties in PDMS microfilms. This allows one to design substrates that flex with varying amounts of strain on the surface. Combining the mechanics of two dimensional materials with that of a locally irradiated PDMS film could achieve a new class of flexible microelectromechanical systems. Large-scale growth of two dimensional materials will be structurally robust-even in the presence of nanostructural defects-and PDMS microfilms can be irradiated to vary strain of the electromechanical systems. These systems could be designed to investigate e
Cooper, Ryan C.
UV-reduction of graphene oxide and its application as an interfacial layer to reduce the back-transport reactions in dye-sensitized solar cells
A mixture of graphene oxide (GO) and TiO 2 nanocomposites was reduced photocatalytically by UV-irradiation and applied as interfacial layer between a fluorine doped tin oxide (FTO) layer and a nanocrystalline TiO 2 film. Impedance spectra implied a decreased back-transport reaction of electrons. The graphene-TiO 2 interfacial layer effectively reduced the contact between I3- ions in the electrolyte and FTO layer, which inhibited back-transport reaction. The introduction of graphene-TiO 2 increased Voc by 54 mV and the photoconversion efficiency was improved from 4.89% to 5.26%.
Kim, Sung Ryong; Parvez, Md. Khaled; Chhowalla, Manish
Synthesis of Cu2ZnSnS4 nanoparticles by solution based solid state reaction process and its application in dye sensitized solar cell as counter electrode
Cu2ZnSnS4 (CZTS) nanoparticles were synthesized by using solution based solid state reaction process and films were coated on FTO (Fluorine doped tin oxide) substrate using doctor blade technique. Phase identification, crystallinity of the synthesized nanoparticles was confirmed by XRD and Raman spectroscopy. Dye sensitized solar cells (DSSC) fabricated with CZTS as counter electrode showed photo conversion efficiency 2.57 % compared to Pt based counter electrode 3.17 % efficiency. The charge transport at CZTS/ electrolyte interface was studied by using electrochemical impedance spectroscopy.
Mokurala, Krishnaiah; Bhargava, Parag; Mallick, Sudhanshu
Characterisation of CdS ? CdTe heterojunctions by photocurrent spectroscopy and electrolyte electroreflectance\\/absorbance spectroscopy (EEA\\/EER)
Thin films (0.02�2.0 ?m) of CdTe were electrodeposited from an acidic electrolyte containing a high concentration of Cd2+ and a low concentration of TeO2 using chemically prepared CdS layers on fluorine-doped tin oxide coated glass as substrates. Characterisation of the as-deposited and thermally annealed CdTe?CdS heterostructures by photocurrent spectroscopy was carried out using transparent stabilising electrolyte contacts (1.0 M Na2SO3),
N. W Duffy; L. M Peter; R. L Wang
Mechanisms of polymeric film formation.
Polymeric films are applied to solid dosage forms for decorative, protective, and functional purposes. These films are generally applied by a spray atomization process, where the polymer is sprayed onto the solid substrate. The mechanism by which films are formed is dependent on whether the polymer is in the dissolved or dispersed state. For solutions, film formation occurs as the solvent evaporates, since the polymer chains are intimately mixed. Film formation from polymeric dispersions, however, requires the coalescence of individual polymer spheres and interpenetration of the polymer chains. Films prepared from polymeric dispersions exhibit a minimum film forming temperature and processing conditions must exceed this temperature in order to form the film. In addition, these systems generally require post-coating storage in temperature and humidity controlled environments to ensure complete polymer coalescence. Incomplete coalescence can lead to significant changes in drug release over time. This review article highlights the basic science principles involved in film formation from both polymeric solutions and dispersions and the variables that influence these film formation processes. PMID:23305867
Felton, Linda A
Advanced thin film thermocouples
The fabrication, materials characterization, and performance of thin film platinum rhodium thermocouples on gas turbine alloys was investigated. The materials chosen for the study were the turbine blade alloy systems MAR M200+Hf with NiCoCrAlY and FeCrAlY coatings, and vane alloy systems MAR M509 with FeCrAlY. Research was focussed on making improvements in the problem areas of coating substrate stability, adhesion, and insulation reliability and durability. Diffusion profiles between the substrate and coating with and without barrier coatings of Al2O3 are reported. The relationships between fabrication parameters of thermal oxidation and sputtering of the insulator and its characterization and performance are described. The best thin film thermocouples were fabricated with the NiCoCrAlY coatings which were thermally oxidized and sputter coated with Al2O3.
Kreider, K. G.; Semancik, S.; Olson, C.
Philip Elwood Films
Philip Elwood was born in New York in 1884, and after he took his degree in landscape architecture from Cornell University, he worked in New York City and eventually ended up working as a professor of landscape architecture at Iowa State University. He had a long and productive career, and his accomplishments include service on the National Resources Planning Board and working as a site planner for Boys Town outside of Omaha. He enjoyed using his 16mm camera to document his travels, and this online collection created by the Iowa State University Libraries brings together seventeen of his short travelogues. The films are silent, and Professor Elwood inserted title cards so viewers will know what they are seeing as they watch. Visitors shouldn't miss the "California to Ames" film as it features great footage of the Mesa Verde National Park, a Zuni Indian village near Gallup, New Mexico, and the annual Shrine picnic on the ISU campus.
Thin film resonator technology.
Advances in wireless systems have placed increased demands on high performance frequency control devices for operation into the microwave range. With spectrum crowding, high bandwidth requirements, miniaturization, and low cost requirements as a background, the thin film resonator technology has evolved into the mainstream of applications. This technology has been under development for over 40 years in one form or another, but it required significant advances in integrated circuit processing to reach microwave frequencies and practical manufacturing for high-volume applications. This paper will survey the development of the thin film resonator technology and describe the core elements that give rise to resonators and filters for today's high performance wireless applications. PMID:16048174
Lakin, Kenneth M
Freely floating smectic films.
We have investigated the dynamics of freely floating smectic bubbles using high-speed optical imaging. Bubbles in the size range from a few hundred micrometers to several centimeters were prepared from collapsing catenoids. They represent ideal model systems for the study of thin-film fluid dynamics under well-controlled conditions. Owing to the internal smectic layer structure, the bubbles combine features of both soap films and vesicles in their unique shape dynamics. From a strongly elongated initial shape after pinch-off, they relax towards the spherical equilibrium, first by a slow redistribution of the smectic layers, and finally by weak, damped shape oscillations. In addition, we describe the rupture of freely floating smectic bubbles, and the formation and stability of smectic filaments. PMID:24692347
May, Kathrin; Harth, Kirsten; Trittel, Torsten; Stannarius, Ralf
Wetting Film Dynamics.
The spreading of a tiny macroscopic drop of a nonvolatile, completely wetting liquid over a flat solid is considered, assuming no gravitation. A liquid, in creeping, is subjected to capillary forces and van der Waals forces. This nonstationary and nonlinear problem in the dynamics of the wetting film from a droplet is studied using numerical modeling. The precursor wetting film motion is described by an evolution equation with conditions at the moving boundaries. The wetting line is regarded as an unknown boundary to be determined in the course of solution. A simplified equation for the wetting line dynamics is analyzed. The difference between the wetting line radius and a fixed (nonzero) radius is described by a diffusion time law. Results of numerical experiments show the simplified law of wetting to be valid over a wide range of spreading times (or a wide range of radii of the wetting line). Copyright 2000 Academic Press. PMID:11401342
Voinov, Oleg V.
Thin Hot-Film Sensors On Polyimide Film
Array of closely spaced hot-film sensors with thickness well below critical reference height with regard to air-flow pattern nonintrusively detect laminar boundary-layer transitions with very high resolution. Method developed at NASA Langley Research Center to fabricate such sensors on polyimide films to detect boundary-layer transitions with resolution as high as 0.050 in. These films formed by combination of vacuum deposition and photolithography.
Hopson, Purnell
CVD Diamond Films for Tribological Applications.
Friction and wear behavior of several types of diamond film has been studied using sapphire on diamond film and diamond on diamond film tests. The coefficient of friction of the films was found to be a strong function of film morphology for sapphire on di...
I. Hayward J. Wegand L. S. Plano
Sputtered Thin Film Research.
The reactive rf sputtering technique was applied to the preparation of a wide variety of materials. Single crystal films of ZnO, TiO2, WO3 AlN and GaN were grown on one or more of the insulating crystalline substrates of Al2O3, MgAl2O3, SiC and LiNbO3. Da...
A. J. Shuskus D. E. Cullen D. J. Quinn E. L. Paradis J. M. Berak
Thin film composite electrolyte
The invention is a thin film composite solid (and a means for making such) suitable for use as an electrolyte, having a first layer of a dense, non-porous conductive material; a second layer of a porous ionic conductive material; and a third layer of a dense non-porous conductive material, wherein the second layer has a Coefficient of thermal expansion within 5% of the coefficient of thermal expansion of the first and third layers.
Schucker, Robert C. (The Woodlands, TX)
Nonlinear optical thin films
A focused approach to development and evaluation of organic polymer films for use in optoelectronics is presented. The issues and challenges that are addressed include: (1) material synthesis, purification, and the tailoring of the material properties; (2) deposition of uniform thin films by a variety of methods; (3) characterization of material physical properties (thermal, electrical, optical, and electro-optical); and (4) device fabrication and testing. Photonic materials, devices, and systems were identified as critical technology areas by the Department of Commerce and the Department of Defense. This approach offers strong integration of basic material issues through engineering applications by the development of materials that can be exploited as the active unit in a variety of polymeric thin film devices. Improved materials were developed with unprecedented purity and stability. The absorptive properties can be tailored and controlled to provide significant improvement in propagation losses and nonlinear performance. Furthermore, the materials were incorporated into polymers that are highly compatible with fabrication and patterning processes for integrated optical devices and circuits. By simultaneously addressing the issues of materials development and characterization, keeping device design and fabrication in mind, many obstacles were overcome for implementation of these polymeric materials and devices into systems. We intend to considerably improve the upper use temperature, poling stability, and compatibility with silicon based devices. The principal device application that was targeted is a linear electro-optic modulation etalon. Organic polymers need to be properly designed and coupled with existing integrated circuit technology to create new photonic devices for optical communication, image processing, other laser applications such as harmonic generation, and eventually optical computing. The progression from microscopic sample to a suitable film-forming material in a working device is a complex, multifaceted endeavor. It requires close attention to maintaining the optical properties of the electro-optic active portion of the polymer while manipulating the polymer structure to obtain the desired secondary polymer properties.
Leslie, Thomas M.
Thick film conductor compositions
A copper-containing thick film conductor composition comprising a mixture of finely divided particles of a conductive material containing copper metal, inorganic binder and 0.2-5% wt. of a noncuprous metal selected from the group consisting of tungsten, molybdenum, rhenium and alloys and mixtures thereof all dispersed in organic medium. The metal particles must be within certain narrow ranges of particle size.
Gold thick film conductors
Conventional thick film conductors rely for their adhesion on the formation of a glassy layer which keys them both chemically\\u000a and mechanically to the substrate surface. A newer type of conductor contains no glass frit but is reactively-bonded to the\\u000a substrate, resulting in different properties which may be advantageous for certain applications. This article is based upon\\u000a a contribution presented
M. V. Coleman; G. E. Gurnett
Spring magnet films.
The properties of exchange-spring-coupled bilayer and superlattice films are highlighted for Sm-Co hard magnet and Fe or Co soft magnet layers. The hexagonal Sm-Co is grown via magnetron sputtering in a- and b-axis epitaxial orientations. In both cases the c-axis, in the film plane, is the easy axis of magnetization. Trends in coercivity with film thickness are established and related to the respective microstructure of the two orientations. The magnetization reversal process for the bilayers is examined by magnetometry and magneto-optical imaging, as well as by simulations that utilize a one-dimensional model to provide the spin configuration for each atomic layer. The Fe magnetization is pinned to that of the Sm-Co at the interface, and reversal proceeds via a progressive twisting of the Fe magnetization. The Fe demagnetization curves are reversible as expected for a spring magnet. Comparison of experiment and simulations indicates that the spring magnet behavior can be understood from the intrinsic properties of the hard and soft layers. Estimated are made of the ultimate gain in performance that can potentially be realized in this system.
Bader, S. D.; Fullerton, E. E.; Gornakov, V. S.; Inomata, A.; Jiang, J. S.; Nikitenko, V. I.; Shapiro, A. J.; Shull, R. D.; Sowers, C. H.
Diamond films for laser hardening
Laser-damage experiments were performed on free-standing polycrystalline diamond films prepared by plasma-enhanced CVD. The high laser-induced stress resistance found for this material makes it useful for thin-film coatings for laser optics. Results for diamond-coated silicon substrates demonstrate the enhanced damage threshold imparted by diamond thin-film coatings to materials susceptible to laser damage.
Albin, S.; Watkins, L.; Ravi, K.; Yokota, S.
A solid state film transport
A solid state film transport utilizing piezoelectric motion was evaluated and found to have potential in film positioning applications. The concept is particularly useful in flight equipment where torque motors and conventional transport mechanisms are difficult to apply. A demonstration model utilizing 5-inch film was designed, tested, and evaluated. Three basic operating modes were investigated. Design goals for step size were achieved under controlled conditions. The continuous mode test results were marred by an inability to transfer efficiently the piezoceramic motion to the film itself. The design, test results, and problem areas are described.
Davis, C. M.; Learish, D. B.
This invention comprises a method to form a family of supported films with pore size in the approximate range 0.8-20 nm exhibiting highly ordered microstructures and porosity derived from an ordered micellar or liquid-crystalline organic-inorganic precursor structure that forms during film deposition. Optically transparent, 100-500-nm thick films exhibiting a unique range of microstructures and uni-modal pore sizes are formed in seconds in a continuous coating operation. Applications of these films include sensors, membranes, low dielectric constant interlayers, anti-reflective coatings, and optical hosts. 12 figs.
Brinker, C.J.; Anderson, M.T.; Ganguli, R.; Lu, Y.F.
21 CFR 892.1840 - Radiographic film.
Code of Federal Regulations, 2010 CFR
...2010-04-01 false Radiographic film. 892.1840 Section 892.1840...Devices § 892.1840 Radiographic film. (a) Identification. Radiographic film is a device that consists of a thin sheet of radiotransparent...
...2009-04-01 false Radiographic film. 892.1840 Section 892.1840...Devices § 892.1840 Radiographic film. (a) Identification. Radiographic film is a device that consists of a thin sheet of radiotransparent...
Synthesis of Diamond Films with Pulsed Plasma.
Diamond films were grown in plasmas formed with microwaves that were modulated with a pulsed generator. Films obtained with the use of pulse periods in the nanosecond, microsecond, and millisecond ranges were compared to baseline films which were obtained...
D. Brock M. Aklufi
Conductor Structure for Thick Film Electrical Device.
A thick film device conductor arrangement is described, suitable for making connections between a resiliently mounted element such as a surface acoustic delay line and adjacent thick film conductors and then with the device connecting pins. The thick film...
M. D. Adamo C. U. Darter F. U. Cho
Electrically conductive palladium-containing polyimide films
Palladium addition makes light, flexible film with low resistivity to relieve space charging. Polyimide film is prepared in four steps: preparation of polyamic acid in polar solvent; addition of soluable palladium complex salt; fabrication of film of "palladium polyamic acid" solution; and thermal imidization of film to palladium-containing polyimide by 300 C heating. Lowered resistivities were achieved without loss in film flexibility or increase in film weight.
St.clair, A. K.; Furtsch, T. A.; Taylor, L. T.
Radiation grafting on natural films
Different methods of polymer grafting using gamma irradiation are reported in the present study for the preparation of newly functionalized biodegradable films, and some important properties related to their mechanical and barrier properties are described. Biodegradable films composed of zein and poly(vinyl alcohol) (PVA) were gamma-irradiated in presence of different ratios of acrylic acid (AAc) monomer for compatibilization purpose. Resulting grafted films (zein/PVA-g-AAc) had their puncture strength (PS=37-40 N mm-1) and puncture deformation (PD=6.5-9.8 mm) improved for 30% and 50% PVA in blend, with 5% AAc under 20 kGy. Methylcellulose (MC)-based films were irradiated in the presence of 2-hydroxyethyl methacrylate (HEMA) or silane, in order to determine the effect of monomer grafting on the mechanical properties of films. It was found that grafted films (MC-g-HEMA and MC-g-silane) using 35% monomer performed higher mechanical properties with PS values of 282-296 N mm-1 and PD of 5.0-5.5 mm under 10 kGy. Compatibilized polycaprolactone (PCL)/chitosan composites were developed via grafting silane in chitosan films. Resulting trilayer grafted composite film (PCL/chitosan-g-silane/PCL) presented superior tensile strength (TS=22 MPa) via possible improvement of interfacial adhesion (PCL/chitosan) when using 25% silane under 10 kGy. Finally, MC-based films containing crystalline nanocellulose (CNC) as a filling agent were prepared and irradiated in presence of trimethylolpropane trimethacrylate (TMPTMA) as a grafted plasticizer. Grafted films (MC-g-TMPTMA) presented superior mechanical properties with a TS of 47.9 MPa and a tensile modulus (TM) of 1792 MPa, possibly due to high yield formation of radicals to promote TMPTMA grafting during irradiation. The addition of CNC led to an additional improvement of the barrier properties, with a significant 25% reduction of water vapor permeability (WVP) of grafted films.
Lacroix, M.; Khan, R.; Senna, M.; Sharmin, N.; Salmieri, S.; Safrany, A.
Reference dosimetry using radiochromic film.
The objectives of this study are to identify and quantify factors that influence radiochromic film dose response and to determine whether such films are suitable for reference dosimetry. The influence of several parameters that may introduce systematic dose errors when performing reference dose measurements were investigated. The effect of the film storage temperature was determined by comparing the performance of three lots of GAFCHROMIC EBT2 films stored at either 4�C or room temperature. The effect of high (> 80%) or low (< 20%) relative humidity was also determined. Doses measured in optimal conditions with EBT and EBT2 films were then compared with an A12 ionization chamber measurement. Intensity-modulated radiation therapy quality controls using EBT2 films were also performed in reference dose. The results obtained using reference dose measurements were compared with those obtained using relative dose measurements. Storing the film at 4�C improves the stability of the film over time, but does not eliminate the noncatalytic film development, seen as a rise in optical density over time in the absence of radiation. Relative humidity variations ranging from 80% to 20% have a strong impact on the optical density and could introduce dose errors of up to 15% if the humidity were not controlled during the film storage period. During the scanning procedure, the film temperature influences the optical density that is measured. When controlling for these three parameters, the dose differences between EBT or EBT2 and the A12 chamber are found to be within � 4% (2? level) over a dose range of 20-350 cGy. Our results also demonstrate the limitation of the Anisotropic Analytical Algorithm for dose calculation of highly modulated treatment plans. PMID:23149793
Girard, Fr�d�ric; Bouchard, Hugo; Lacroix, Fr�d�ric
Sundance Film Festival Announces Winners
Film festivals have become immensely popular during the last few decades, and it seems like almost every city or state now has some type of festival to showcase the work of local, national, and in some cases, international filmmakers, both young and old. Started by Robert Redford in 1981, the Sundance Film Festival (held annually in Park City, Utah) has quickly grown into one of the most prestigious celebrations of filmmaking in the world. Earlier this week, the Sundance Film Festival announced its awards in the Independent Feature Film Competition. Among the winners were "Capturing the Friedmans" (which won the Documentary Grand Jury Prize), "American Splendor" (which received the Dramatic Grand Jury Prize), and "My Flesh and Blood" (which received the Documentary Audience Award).The first site leads to the official 2003 Sundance Film Festival site that contains a wealth of material, including lists of all films shown at the festival and detailed information about the juries for the different competitions. The second link is to a news article from the Washington Post that reports on various award recipients of this year's Sundance Film Festival competition. The third link is to an online article that discusses the making of the film "Capturing the Friedmans" with the director, Andrew Jarecki. The fourth site leads to an interview with the noted comic book author Harvey Pekar, whose life was chronicled by director Shari Springer for her 2003 Sundance Festival award-winning film, "American Splendor." The fifth site leads to the Full Frame Documentary Film Festival home page, which was founded in 1998 to showcase the work of documentary filmmakers solely. The final site, Filmfestivals.com, is the clearinghouse for information about almost every single film festival in the world, and contains a search engine, detailed calendars of upcoming events, and frequently updated information about upcoming releases.
Grinnell, Max
National Film Preservation Foundation: The Film Preservation Guide
No doubt many organizations and institutions have a canister of 16MM film lying around someplace and some diligent member of their organization might ask: "How can we preserve this item?" A very astute question, and this helpful guide from the National Film Preservation Foundation provides substantial guidance and assistance. The 121-page guide describes methods for handling, duplicating, making available, and storing film, which are practical for nonprofit and public organizations with limited resources. Visitors to this site can download all of the sections in this report, which include chapters like "Legal Context for Film Preservation" and "Understanding Film and How it Decays". The report also includes case studies, illustrations, charts, glossary, and a bibliography.
Liquid film demonstration experiment Skylab SL-4
The liquid film demonstration experiment performed on Skylab 4 by Astronaut Gerald Carr, which involved the construction of water and soap films by boundary expansion and inertia, is discussed. Results include a 1-ml globule of water expanded into a 7-cm-diameter film as well as complex film structures produced by inertia whose lifetimes are longer in the low-g environment. Also discussed are 1-g acceleration experiments in which the unprovoked rupture of films was photographed and film lifetimes of stationary and rotated soap films were compared. Finally, there is a mathematical discussion regarding minimal surfaces, an isoperimetric problem, and liquid films.
Darbro, W.
Electrical initiation of an energetic nanolaminate film
A heating apparatus comprising an energetic nanolaminate film that produces heat when initiated, a power source that provides an electric current, and a control that initiates the energetic nanolaminate film by directing the electric current to the energetic nanolaminate film and joule heating the energetic nanolaminate film to an initiation temperature. Also a method of heating comprising providing an energetic nanolaminate film that produces heat when initiated, and initiating the energetic nanolaminate film by directing an electric current to the energetic nanolaminate film and joule heating the energetic nanolaminate film to an initiation temperature.
Tringe, Joseph W. (Walnut Creek, CA) [Walnut Creek, CA; Gash, Alexander E. (Brentwood, CA) [Brentwood, CA; Barbee, Jr., Troy W. (Palo Alto, CA)
Fire resistant films for aircraft applications
Alternative sandwich panel decorative films were investigated as replacements for the polyvinyl fluoride currently used in aircraft interiors. Candidate films were studied for flammability, smoke emission, toxic gas emission, flame spread, and suitability as a printing surface for the decorative acrylic ink system. Several of the candidate films tested were flame modified polyvinyl fluoride, polyvinylidene fluoride, polyimide, polyamide, polysulfone, polyphenylsulfone, polyethersulfone, polybenzimidazole, polycarbonate, polyparabanic acid, polyphosphazene, polyetheretherketon, and polyester. The films were evaluated as pure films only, films silk-screened with an acrylic ink, and films adhered to a phenolic fiberglass substrate. Films which exhibited the highest fire resistant properties included PEEK polyetheretherketon, Aramid polyamide, and ISO-BPE polyester.
Kourtides, D. A.
Protective Film Moves Aside
Antibacterial Biomimetic Hybrid Films
In this work, we present a novel method to prepare a hybrid coating based on dextran grafted to a substrate and embedded with silver nanoparticles (Ag NPs). First, the Ag NPs are synthesized in situ in the presence of oxidized dextran in solution. Second, the oxidized dextran is exposed to an amine functionalized surface resulting in the simultaneous grafting of dextran and the trapping of Ag NPs within the layer. The NP loading is controlled by the concentration of silver nitrate, which is 2 mM (DEX-Ag2) and 5 mM (DEX-Ag5). The dried film thickness increases with silver nitrate concentration from 2 nm for dextran to 7 nm and 12 nm for DEX-Ag2 and DEX-Ag5, respectively. The grafted dextran film displays features with a diameter and height of ~ 50 nm and 2 nm, respectively. For the DEX-Ag2 and DEX-Ag5, the dextran features as well as individual Ag NPs (~ 5 nm) and aggregates of Ag NPs are observed. Larger and more irregular aggregates are observed for DEX-Ag5. Overall, the Ag NPs are embedded in the dextran film as suggested by AFM and UVO studies. In terms of its antimicrobial activity, DEX-Ag2 resists bacterial adhesion to a greater extent than DEX-Ag5, which in turn is better than dextran and silicon. Because these antibacterial hybrid coatings can be grafted to a variety of surfaces, many biomedical applications can be envisioned, ranging from coating implants to catheters.
Ferrer, M. Carme Coll; Hickok, Noreen J.; Eckmann, David M.; Composto, Russell J.
Science Books and Films
Science Books and Films bills itself as "the authoritative guide to science resources, bringing you the expert information you need to make the best decisions when choosing science materials for your library, classroom, or institution." The subscriber section of the site allows access to more than 9,000 science reviews that can be shaped into personalized bibliographies by subject area, grade level, and author. For non-subscribers, articles from past years are offered, including the Best Books for Children, Best Books for Junior High and High School Readers, and Best Videos and Software.
Carbonaceous film coating
A method of making a carbonaceous film comprising heating tris(1,3,2-benzodiazaborolo)borazine or dodecahydro tris(1,3,2)diazaborine(1,2-a:1'2'-c:1''2''-e)borazine in an inert atmosphere in the presence of a substrate to a temperature at which the borazine compound decomposes, and the decomposition products deposit onto the substrate to form a thin, tenacious, highly reflective conductive coating having a narrow band gap which is susceptible of modification and a relatively low coefficient of friction.
Maya, L.
Thin film hydrogen sensor
A hydrogen sensor element comprises an essentially inert, electrically-insulating substrate having a thin-film metallization deposited thereon which forms at least two resistors on the substrate. The metallization comprises a layer of Pd or a Pd alloy for sensing hydrogen and an underlying intermediate metal layer for providing enhanced adhesion of the metallization to the substrate. An essentially inert, electrically insulating, hydrogen impermeable passivation layer covers at least one of the resistors, and at least one of the resistors is left uncovered. The difference in electrical resistances of the covered resistor and the uncovered resistor is related to hydrogen concentration in a gas to which the sensor element is exposed.
Lauf, Robert J. (Oak Ridge, TN) [Oak Ridge, TN; Hoffheins, Barbara S. (Knoxville, TN) [Knoxville, TN; Fleming, Pamela H. (Oak Ridge, TN) [Oak Ridge, TN
A Film Canister Colorimeter
A low-cost, low-tech colorimeter was constructed from a film canister. The light source and filter monochromator was an interchangeable LED. The detector for this system was a voltage-divider circuit composed of a photoresistor in series with a fixed resistor. The student-constructed colorimeter was used to show the Beer–Lambert relationship between absorbance and concentration and to calculate the value of the molar absorptivity for permanganate at the wavelength emission maximum for the LED. Comparisons were made between this instrument and three commercial spectrometers and colorimeters.
Gordon, James; James, Alan; Harman, Stephanie; Weiss, Kristen
Giant magnetoresistance in electrodeposited films
Electrodeposition is one of the simpler and cheaper processes available for the fabrication of thin metal films. Recent developments have made it possible to electrodeposit a wide range of nanostructured materials, including many that exhibit giant magnetoresistance (GMR). We review progress in the growth and characterization of such films, starting with electrodeposited ferromagnetic metal\\/non-magnetic metal superlattices in which the individual
W. Schwarzacher; D. S. Lashmore
Falling films on flexible inclines
The nonlinear stability and dynamic behavior of falling fluid films is studied for flow over a flexible substrate. We use asymptotic methods to deduce governing equations valid in various limits. Long-wave theory is used to derive Benney-like coupled equations for the film thickness and substrate deflection. Weakly nonlinear equations are then derived from these equations that, in the limit of
O. K. Matar; R. V. Craster; S. Kumar
Improved Dielectric Films For Capacitors
Dielectric films made from blends of some commercially available high-dielectric-constant cyanoresins with each other and with cellulose triacetate (CTA) have both high dielectric constants and high breakdown strengths. Dielectric constants as high as 16.2. Films used to produce high-energy-density capacitors.
Yen, Shiao-Ping S.; Lewis, Carol R.; Cygan, Peter J.; Jow, T. Richard
Film Library Information Management System.
The computer program described not only allows the user to determine rental sources for a particular film title quickly, but also to select the least expensive of the sources. This program developed at SUNY Cortland's Sperry Learning Resources Center and Computer Center is designed to maintain accurate data on rental and purchase films in both�
Minnella, C. Vincent; And Others
Mercury wetting film on sapphire
We have measured optical properties of a mercury wetting film on sapphire under high temperature and high pressure near the liquid-gas critical point of mercury by using a newly developed 45� reflection technique. We have analyzed the experimental data to deduce the density, the thickness, and the coverage of the wetting film quantitatively as functions of pressure and temperature. As
Y. Ohmasa; Y. Kajihara; M. Yao
Cinemabilia; Catalogue of Film Literature.
The catalog lists and briefly annotates more than 3,500 current, second-hand, and out-of-print books about film that are available from Cinemabilia, New York City. The catalog is divided into 37 categories. The section on special genre lists works on horror, science fiction, Westerns, and Tarzan films, ranging from "Drums of Fu-Manchu" to "Movie�
Cinemabilia, New York, NY.
Metal oxide films on metal
A structure including a thin film of a conductive alkaline earth metal oxide selected from the group consisting of strontium ruthenium trioxide, calcium ruthenium trioxide, barium ruthenium trioxide, lanthanum-strontium cobalt oxide or mixed alkaline earth ruthenium trioxides thereof upon a thin film of a noble metal such as platinum is provided.
Wu, Xin D. (Los Alamos, NM); Tiwari, Prabhat (Los Alamos, NM)
Liquid-film electron stripper
An improved liquid-film electron stripper particularly for high intensity heavy ion beams which produces constant regenerated, stable, free-standing liquid films having an adjustable thickness between 0.3 to 0.05 microns. The improved electron stripper is basically composed of at least one high speed, rotating disc with a very sharp, precision-like, ground edge on one said of the disc's periphery and with a highly polished, flat, radial surface adjacent the sharp edge. A fine stream of liquid, such as oil, impinges at a 90.degree. angle adjacent the disc's sharp outer edge. Film terminators, located at a selected distance from the disc perimeter are positioned approximately perpendicular to the film. The terminators support, shape, and stretch the film and are arranged to assist in the prevention of liquid droplet formation by directing the collected film to a reservoir below without breaking or interfering with the film. One embodiment utilizes two rotating discs and associated terminators, with the discs rotating so as to form films in opposite directions, and with the second disc being located down beam-line relative to the first disc.
Gavin, Basil F. (Albion, CA) [Albion, CA
Deformation of an asymmetric film
Recent experiments have investigated shape changes of polymer films induced by asymmetric swelling by a chemical vapor. Inspired by recent work on the shaping of elastic sheets by non-Euclidean metrics [1,2], we represent the effect of chemical vapors by a change in the target metric tensor. In this problem, unlike Refs. [1,2], the target metric is asymmetric between the two sides of the film. Changing this metric induces a curvature of the film, which may be Gaussian curvature into a sphere or mean curvature into a cylinder. We calculate the elastic energy for each of these shapes, and show that the sphere is favored for films smaller than a critical size, which depends on the film thickness, while the cylinder is favored for larger films. We compare the formalism for asymmetric films with previous theoretical work on symmetric films, and compare the predictions with experimental results. [4pt] [1] Y. Klein, E. Efrati, and E. Sharon, Science 315, 1116 (2007).[0pt] [2] E. Efrati, E. Sharon, and R. Kupferman, J. Mech. Phys. Solids 57, 762 (2009).
Geng, Jun; Selinger, Jonathan
Thin Film Inorganic Electrochemical Systems.
During the 21 month period of this contract we have studied components for an all inorganic thin film lithium ion cell. During this work we have determined that thin film cathodes of LiCoO2 can be readily performed by either spray pyrolysis or spin coatin...
D. M. Schleich
Liquid Permeation Through Plastic Films.
Liquid permeation through plastic films promises to be a valuable technique for the separation of organic compounds. The overwhelming drawback of the process is the inability of current knowledge to predict what type of film is required for a particular s...
R. F. Sweeny
Thin film atomic hydrogen detectors
Thin film and bead thermistor atomic surface recombination hydrogen detectors were investigated both experimentally and theoretically. Devices were constructed on a thin Mylar film substrate. Using suitable Wheatstone bridge techniques sensitivities of 80 microvolts/2x10 to the 13th power atoms/sec are attainable with response time constants on the order of 5 seconds.
Gruber, C. L.
Thin film corrosion. Final report
Corrosion of chromium/gold (Cr/Au) thin films during photolithography, prebond etching, and cleaning was evaluated. Vapors of chromium etchant, tantalum nitride etchant, and especially gold etchant were found to corrosively attack chromium/gold films. A palladium metal barrier between the gold and chromium layers was found to reduce the corrosion from gold etchant.
Raut, M.K.
Microtribology of PET Polymeric Films
Atomic force microscopy (AFM) and friction force microscopy (FFM) are used to conduct microtribological studies of thin polyethylene terephthalate (PET) films which are commonly used in many industrial applications including as a magnetic tape substrate. In the PET films, microscale friction values are found to be smaller than macrofriction values. Local variation in microscale friction is found to correspond to
Bharat Bhushan; Vilas N. Koinkar
Films and the English Class.
The importance of film in the English classroom and its vitality in the English curriculum are discussed. Articles that comprise this issue of the bulletin are: The Trouble with Film Teaching by James E. Cutts; "You Ain't Heard Nothin' Yet" or Send Your Students to the Flicks Tonight by Bob Haskett; It's the Reel Thing: The Verite of Cinema Is�
Donelson, Kenneth, Ed.
The Thin Oil Film Equation
A thin film of oil on a surface responds primarily to the wall shear stress generated on that surface by a three-dimensional flow. The oil film is also subject to wall pressure gradients, surface tension effects and gravity. The partial differential equation governing the oil film flow is shown to be related to Burgers' equation. Analytical and numerical methods for solving the thin oil film equation are presented. A direct numerical solver is developed where the wall shear stress variation on the surface is known and which solves for the oil film thickness spatial and time variation on the surface. An inverse numerical solver is also developed where the oil film thickness spatial variation over the surface at two discrete times is known and which solves for the wall shear stress variation over the test surface. A One-Time-Level inverse solver is also demonstrated. The inverse numerical solver provides a mathematically rigorous basis for an improved form of a wall shear stress instrument suitable for application to complex three-dimensional flows. To demonstrate the complexity of flows for which these oil film methods are now suitable, extensive examination is accomplished for these analytical and numerical methods as applied to a thin oil film in the vicinity of a three-dimensional saddle of separation.
Brown, James L.; Naughton, Jonathan W.
What's New in Film Literacy.
Argues English teachers should stop treating film as a back-up activity and instead embrace it as a visual reinforcement of the curriculum. Describes how film can be used to teach literary terms such as protagonist, antagonist, conflict, setting, and characterization; to introduce material; and to introduce students to authors they may not�
Jolly, Sherrill
Thermoplastic film prevents proppant flowback
Thermoplastic film added to proppants is effective and economical for preventing proppant flowback after an hydraulic fracturing treatment. Most other methods, such as resin-coated proppant and fiber, for controlling proppant flowback have drawbacks that added to treatment costs by requiring long downtime, costly additives, or frequent equipment replacement. Thermoplastic film does not react chemically with fracturing fluids. After the proppant
P. D. Nguyen; J. D. Weaver; M. A. Parker; D. G. King
Fibronectin in the Tear Film
Purpose. Fibronectin plays an important role in corneal wound healing and has been detected previously in the tear film. To investigate the levels of fibronectin in normal human tears, the authors measured and compared fibronectin concentration in open-eye, closed-eye, and reflex tear fluid. The origin of fibronectin in the tear film was investigated by comparing fibronectin concentration in sequentially collected
Masahiko Fukuda; Roderick J. Fullard; Mark D. P. Willcox; Cristina Baleriola-Lucas; Fakhry Bestaxvros; Deborah Sweeney; Brien A. Holden
A Wet Film Thickness Gage.
The patent application describes a wet film thickness gage which provides a constant applied force independent of the support housing so as to enable the user to measure the thickness of wet film on a pliable substrate. A variable tension spring is used t...
D. J. Butler R. J. Toups
Sectioned thin-film grating
The resolving power of metallic linear gratings deposited on a dielectric thin-film waveguide can be increased by separating sections of the grating by blank spaces. Because of the high coupling efficiencies of gratings deposited directly on the waveguide, the effects of the blank spaces cannot be observed for such guides. If a dielectric film with an index of refraction less
W. D. Westwood; J. W. Y. Lit
Laser refractometry of edible films
Refraction index of edible films from polysaccharides (pectin, xanthan, carboxy-methyl-cellulose, polymixan) has been investigated using laser microrefractomeeter, constructed by the authors. Experimental data about the optical density and the thickness of the edible films have been obtained. The results from the investigation can be used in the development of new packing technologies for food products.
Panchev, I.; Nikolova, K.; Sainov, Simeon C.
Photoelectrochemistry of disordered passive films
A theoretical model, which describes subband gap photoexcitation involving localized electronic states, was developed. The escape probability of a charge carrier trapped in a localized state is considered via Poole-Frenkel, direct tunneling, or phonon-assisted tunneling processes, as competing escape mechanisms. Photoelectrochemical experiments were performed on the passive films formed on zirconium and amorphous iron-zirconium alloys and on pure HfO/sub 2/ films and HfO/sub 2/ films implanted with varying concentrations of xenon. These films were found to possess some degree of disorder depending on the substrate, the thickness of the film, and the extent of implantation. The spectral dependence of the photocurrent in all of the films studied is considerably different from what was found for crystalline passive films. The potential dependence of the photocurrent yields Poole-Frenkel behavior. Reverse tunneling processes were also observed at low photon energies and low fields across the film, which is consistent with the theoretical results.
Newark, A.R.
Film Study: A Resource Guide.
This resource guide describes six popular approaches to the study of the cinema and provides a practical analysis of selected books, materials, and information about motion picture rentals. Highlighting this extensive survey of film studies are the annotated, critical bibliographies and filmographies of significant books, articles and films by and�
Manchel, Frank
Film Thickness Dependence of Coercivity in Obliquely Vacuum Deposited Co-Cr Films
The film thickness dependence of the coercivity in obliquely vacuum-deposited Co-Cr films and Co films was studied. A coercivity of 80 kA\\/m was obtained for Co-Cr films obliquely deposited at a substrate temperature of 80�C. The coercivity of obliquely deposited Co-Cr films was larger than the values of obliquely deposited Co films and normally deposited Co-Cr films. The high coercivity
K. Honda; Y. Maezawa; R. Sugita
Anode film formation and control
A protective film is created about the anode within a cryolite-based electrolyte during electrolytic production of aluminum from alumina. The film function to minimize corrosion of the anode by the cryolitic electrolyte and thereby extend the life of the anode. Various operating parameters of the electrolytic process are controlled to maintain the protective film about the anode in a protective state throughout the electrolytic reduction of alumina. Such parameters include electrolyte temperature, electrolyte ratio, current density, and Al.sub.2 O.sub.3 concentration. An apparatus is also disclosed to enable identification of the onset of anode corrosion due to disruption of the film to provide real time information regarding the state of the film.
Koski, Oscar (Richland, WA) [Richland, WA; Marschman, Steven C. (Richland, WA) [Richland, WA
A protective film is created about the anode within a cryolite-based electrolyte during electrolytic production of aluminum from alumina. The film functions to minimize corrosion of the anode by the cryolitic electrolyte and thereby extend the life of the anode. Various operating parameters of the electrolytic process are controlled to maintain the protective film about the anode in a protective state throughout the electrolytic reduction of alumina. Such parameters include electrolyte temperature, electrolyte ratio, current density, and Al[sub 2]O[sub 3] concentration. An apparatus is also disclosed to enable identification of the onset of anode corrosion due to disruption of the film to provide real time information regarding the state of the film. 3 figs.
Koski, O.; Marschman, S.C.
Film fabrication technologies at NREL
The National Renewable Energy Laboratory (NREL) has extensive capabilities for fabricating a variety of high-technology films. Much of the in-house work in NREL's large photovoltaics (PV) program involves the fabrication of multiple thin-film semiconducting layers constituting a thin-film PV device. NREL's smaller program in superconductivity focuses on the fabrication of superconducting films on long, flexible tape substrates. This paper focuses on four of NREL's in-house research groups and their film fabrication techniques, developed for a variety of elements, alloys, and compounds to be deposited on a variety of substrates. As is the case for many national laboratories, NREL's technology transfer efforts are focusing on Cooperative Research and Development Agreements (CRADA's) between NREL researchers and private industry researchers.
Mcconnell, Robert D.
Soap film gas flowmeter
A soap film gas flowmeter is described comprising: a flow tube having a hollow body with opposite open ends through which a soap film is propelled and a first closed chamber housing a soap solution. It also includes means for supporting the flow tube in a substantially vertical position with the open bottom end of the flow tube disposed in the first chamber above the soap solution; a second closed chamber into which the open top end of the flow tube extends and gas inlet means for introducing gas into the first chamber at a flow rate to be measured using the flowmeters. A gas exit means is included for discharging the gas introduced into the first chamber through the second chamber. Plus there are means for generating a single soap bubble from the soap solution substantially at the bottom end of the flow tube and a relatively large opening in the flowtube for providing an open passageway for inlet gas to pass through the flowtube when the bottom open end of the flowtube is covered by the soap solution.
Lalin, H.S.; Bermudez, J.E.; Fleming, W.T.
Significant effects of reaction temperature on morphology, crystallinity, and photoelectrical properties of rutile TiO2 nanorod array films
Oriented single-crystalline TiO2 nanorod arrays have been extensively studied as the electrode of photoelectrochemical cells due to their unique properties. In this study, oriented rutile TiO2 nanorod arrays were directly synthesized on fluorine-doped tin oxide glass substrates by a facile hydrothermal method, and the effects of growth conditions (i.e. reaction temperature, growth time and titanium precursor) on their morphologies, crystal structures and photoelectrical properties were investigated. Reaction temperature played a more critical role in tailoring the surface morphology, crystal structures (i.e. length, diameter and crystallinity of nanorods) and photoelectrical properties of the nanorods than growth time did. With the increase in reaction temperature from 140 �C to 200 �C, both photocurrent density and external quantum efficiency (EQE) increased initially and then decreased, with a maximum value of 5.6 � 10-2 mA cm-2 at 170 �C and 2.7% at 160 �C, respectively. In addition, photoelectric measurements demonstrated that TiO2 nanorod arrays synthesized from TiCl4 at a relatively low reaction temperature exhibited a much higher EQE value than those obtained from titanium isopropoxide.
Sun, Xianmiao; Sun, Qiong; Zhang, Qian; Zhu, Qianqian; Dong, Hongzhou; Dong, Lifeng
Development of ZnTe layers using an electrochemical technique for applications in thin-film solar cells
Zinc telluride layers were grown by an electrochemical technique using acidic and aqueous solutions containing ZnCl2 and TeO2. The layers were deposited on glass/fluorine-doped tin oxide substrates using a two-electrode system. The deposited ZnTe layers were characterized using x-ray diffraction, x-ray fluorescence, Raman spectroscopy, optical absorption, photoelectrochemical cell measurements, scanning electron microscopy and 3D-atomic force microscopy (3D-AFM) for the structural, optical, electrical and morphological properties. The electrodeposited ZnTe layers grow as columns, and have cubic crystal structure, the band gap in the range of (2.00-2.20) eV and p-type electrical conductivity. Surface morphology studies using SEM indicate the presence of two types of material clusters varying in size up to �125 nm. 3D-AFM studies with higher magnification show that the material tends to grow as columns with different sizes leaving gaps in between in some areas.
Fauzi, F.; Diso, D. G.; Echendu, O. K.; Patel, V.; Purandare, Y.; Burton, R.; Dharmadasa, I. M.
Flight test comparison of film type SO-289 and film type 2424 in the AMPS camera
A flight test was conducted to determine the suitability of SO-289 multispectral infrared aerial film for Earth Resources' use. It was directly compared to film type 2424, infrared aerographic film, the IR film in current use. The exposure parameters for both films are given.
Perry, L.
Characteristics of thin film inductors using magnetic multilayered films with ceramic intermediate layers
Circular spiral thin film inductors were fabricated using as-deposited magnetic multilayered films with ceramic intermediate layers, and a thin film inductor with a single magnetic layer was also fabricated for comparison. The magnetic multilayered films have good soft magnetic properties and high resistivity thus can decrease the eddy current loss. Employing the magnetic multilayered films, we got a higher quality
Xiao-Li Tang; H. W. Zhang; H. Su; Y. Shi; X. D. Jiang
American Film Genres: Approaches to a Critical Theory of Popular Film.
This book is divided into twelve sections and contains photographs from many of the films discussed. The introduction defines film genre and describes the general theories behind this book; "The Individual Film" analyzes the film "Little Caesar" as it relates to the genre of gangster films; "Comparative Forms" describes the similarities and�
Kaminsky, Stuart M.
A Film Marketing Action Plan (FMAP) for Film Induced Tourism Destinations
This research study examines the impact of film induced tourism and destination branding on locations featured in popular films and television series. It also investigates the characteristics of film induced tourism and determines if the key film and tourism stakeholders support the integration of film into Yorkshire�s (UK) tourism product. Yorkshire was selected as the case study area, as it
Noelle OConnor
America on Film: A Humanities Composition Course.
This paper argues that film courses are useful because they sensitize students both to the artistic qualities of film expression and to equivalent qualities in other forms of expression. The objectives of a film course at Michigan State University are: to develop the students' knowledge of the film medium and through that knowledge develop a�
Recchia, Edward
[100]Textured diamond films for tribological applications
Application of CVD diamond films as hard coating on tools may offer, in addition to their mechanical properties, also low friction coefficient. In this sense [100]-textured films are potentially advantageous over non-textured films due to their lower roughness. In the present work we demonstrate the capability to deposit [100]-textured diamond films on steel substrates coated with a nitrided chromium thin
Y. Avigal; O. Glozman; I. Etsion; G. Halperin; A. Hoffman
Sputtered Sulphide Films for Electronic Components
Two types of sputtering have been used to deposit several II-VI compound materials as thin films suitable for various applications. Both reactive and compound sputtering have yielded stable and reproducible films. In either case doping was accomplished during film deposition. Zinc sulphide films have yielded good capacitors with low dissipation, moderate breakdown voltages and High stability. Pronounced photoconductivity was exhibited
T. Lakshmanan; J. Mitchell
Geoflicks Reviewed--Films about Hawaiian Volcanoes.
Reviews 11 films on volcanic eruptions in the United States. Films are given a one- to five-star rating and the film's year, length, source and price are listed. Top films include "Inside Hawaiian Volcanoes" and "Kilauea: Close up of an Active Volcano." (AIM)
Bykerk-Kauffman, Ann
Squeeze-Film Damper Controls High Vibrations
Dual-clearance (two oil films) squeeze-film damper developed for controlling vibrations in aircraft turbine engines and other rotating machinery. New damper under normal conditions uses only one low-clearance film. Under high imbalance, both films active, controlling shaft vibration in nearoptimum manner and allowing continued operation until safe shutdown made.
Fleming, D. P.
Light Amplification in a Thin Film.
Light Amplification at 6328 A in a rhodamine-B-doped polyurethane thin film is observed. The light-guiding thin film is pumped transversely with a nitrogen laser. Superradiant light of the dye-doped film is observed to be guided by the thin film. When a H...
C. Hu J. R. Whinnery M. S. Chang P. Burlamacchi
A 3M high temperature dielectric film
The performance characteristics of a dielectric film are summarized. Additionally, the film's environmental and chemical properties are listed: low shrinkage to 300 C; moisture insensitive; low outgassing under vacuum; excellent surface qualities--easy metallization of film; flame retardant; and low smoke generation. A series of graphs that display the performance characteristics of the film are also presented.
Hampl, Edward, Jr.
Europa Heute: Filmbegleitheft (Europe Today: Film Manual).
This teacher's guide to the German promotional film "Europe Today", suitable for use in advanced courses, concentrates on linguistic preparation required for full appreciation. The film focuses on the role of European countries as participating members of the Common Market. The manual includes information on the German film industry, a film�
Freudenstein, Reinhold; And Others
Are Wildlife Films Really "Nature Documentaries"?
Examines origins of wildlife films. Outlines their tension between education and entertainment. Looks at how Disney codified wildlife films as a coherent genre by imposing conventionalized narrative frameworks upon them. Discusses factors influencing wildlife television in the 1990s. Concludes that wildlife films are a valid and distinct film and�
Bouse, Derek
On the hydrodynamics of soap films
Several experiments aiming at the exploration of the hydrodynamical properties of soap films are presented. Their interpretation takes into account the very specific equation of state of these films. It is shown that on short time scales each element of the film moves as a whole so that the film can be considered as a two-dimensional fluid with a local
Y. Couder; J. M. Chomaz; M. Rabaud
Stress gradients in titanium nitride thin films
Titanium nitride films, as used for hard coatings, were deposited on silicon wafers by reactive unbalanced magnetron sputtering. For thinner films we find a higher compressive average residual stress than for thicker films. In the paper it is shown that this reduction in average stress is not due to relaxation, but to a stress gradient in the film. Experiments in
R. Machunze; G. C. A. M. Janssen
"Space slitter" for film or tape
Device cuts film or tape into strips by guiding film in channel under cutting blades. Device is operated by lifting pressure bar to insert blades into film. Film is then pulled through blades. Cutter has potential uses in advertising, commercial art, and publishing fields.
Johnson, W. H.
A hydrogen sensor element comprises an essentially inert, electrically-insulating substrate having a thin-film metallization deposited thereon which forms at least two resistors on the substrate. The metallization comprises a layer of Pd or a Pd alloy for sensing hydrogen and an underlying intermediate metal layer for providing enhanced adhesion of the metallization to the substrate. An essentially inert, electrically insulating, hydrogen impermeable passivation layer covers at least one of the resistors, and at least one of the resistors is left uncovered. The difference in electrical resistances of the covered resistor and the uncovered resistor is related to hydrogen concentration in a gas to which the sensor element is exposed. 6 figs.
Lauf, R.J.; Hoffheins, B.S.; Fleming, P.H.
Because supplies are limited in many classrooms, opaque film canisters can be used in a number of scientific inquiry activities, including a "black box" activity and several activities on sinking and floating properties related to density and to Archimedes' principle. Although the activities described here were written for pre-service teachers, the intent of this article is to explain how they could be used at elementary, middle, and high school levels. By implementing these activities, students will become adept at solving the "mysteries of science" using science process skills--and learn another important lesson: Scientific explorations do not always have yes/no answers. Careful and unbiased data analysis is essential because the unexpected is always possible.
Importance of combining convection with film cooling
The interaction of film and convection cooling and its effect on wall cooling efficiency is investigated analytically for two cooling schemes for advanced gas turbine applications. The two schemes are full coverage- and counterflow-film cooling. In full coverage film cooling, the cooling air issues from a large number of small discrete holes in the surface. Counterflow film cooling is a film-convection scheme with film injection from a slot geometry. The results indicate that it is beneficial to utilize as much of the cooling air heat sink as possible for convection cooling prior to ejecting it as a film.
Colladay, R. S.
A thin freestanding oil film is produced in vacuum by directing an oil stream radially inward to the hollow-ground sharp outer edge of a rotating disc. The sides of the edge are roughened somewhat to aid in dispersing oil from the disc. Oil is removed from the surface of disc to prevent formation of oil droplets which might spin off the disc and disrupt the oil film. An ion beam is directed through the thin oil film so that electrons are stripped from the ions to increase their charge.
Leemann, Beat T. (Walnut Creek, CA) [Walnut Creek, CA; Yourd, Roland B. (Kensington, CA) [Kensington, CA
Surface nanostructures in manganite films.
Ultrathin manganite films are widely used as active electrodes in organic spintronic devices. In this study, a scanning tunnelling microscopy (STM) investigation with atomic resolution revealed previously unknown surface features consisting of small non-stoichiometric islands. Based upon this evidence, a new mechanism for the growth of these complex materials is proposed. It is suggested that the non-stoichiometric islands result from nucleation centres that are below the critical threshold size required for stoichiometric crystalline growth. These islands represent a kinetic intermediate of single-layer growth regardless of the film thickness, and should be considered and possibly controlled in manganite thin-film applications. PMID:24941969
Gambardella, A; Graziosi, P; Bergenti, I; Prezioso, M; Pullini, D; Milita, S; Biscarini, F; Dediu, V A
Thick-film strain gage
The history and current status of thick-film strain gage technology are briefly reviewed, and data are presented on the performance characteristics of six different types of bonded piezoresistive strain gages. It is shown that the gage factor/thermal sensitivity characteristics make the thick-film strain gage technology attractive for general purpose applications. It is further noted that the low cost of a high-volume production process and a low-cost capsule packaging associated with the thick-film technology can result in low installed cost for measurement of pressure with very acceptable combined errors. 9 references.
Nielsen, H.A. Jr.
Surface Nanostructures in Manganite Films
Ultrathin manganite films are widely used as active electrodes in organic spintronic devices. In this study, a scanning tunnelling microscopy (STM) investigation with atomic resolution revealed previously unknown surface features consisting of small non-stoichiometric islands. Based upon this evidence, a new mechanism for the growth of these complex materials is proposed. It is suggested that the non-stoichiometric islands result from nucleation centres that are below the critical threshold size required for stoichiometric crystalline growth. These islands represent a kinetic intermediate of single-layer growth regardless of the film thickness, and should be considered and possibly controlled in manganite thin-film applications.
Gambardella, A.; Graziosi, P.; Bergenti, I.; Prezioso, M.; Pullini, D.; Milita, S.; Biscarini, F.; Dediu, V. A.
Tailoring nanocrystalline diamond film properties
A method for controlling the crystallite size and growth rate of plasma-deposited diamond films. A plasma is established at a pressure in excess of about 55 Torr with controlled concentrations of hydrogen up to about 98% by volume, of unsubstituted hydrocarbons up to about 3% by volume and an inert gas of one or more of the noble gases and nitrogen up to about 98% by volume. The volume ratio of inert gas to hydrogen is preferably maintained at greater than about 4, to deposit a diamond film on a suitable substrate. The diamond film is deposited with a predetermined crystallite size and at a predetermined growth rate.
Gruen, Dieter M. (Downers Grove, IL) [Downers Grove, IL; McCauley, Thomas G. (Somerville, MA) [Somerville, MA; Zhou, Dan (Orlando, FL) [Orlando, FL; Krauss, Alan R. (Naperville, IL) [Naperville, IL
Film boiling of mercury droplets
Vaporization times of mercury droplets in Leidenfrost film boiling on a flat horizontal plate are measured in an air atmosphere. Extreme care was used to prevent large amplitude droplet vibrations and surface wetting; therefore, these data can be compared to film boiling theory. Diffusion from the upper surface of the drop appears as a dominant mode of mass transfer from the drop. A closed-form analytical film boiling theory is developed to account for the diffusive evaporation. Reasonable agreement between data and theory is seen.
Baumeister, K. J.; Schoessow, G. J.; Chmielewski, C. E.
Vaporization times of mercury droplets in Leidenfrost film boiling on a flat horizontal plate are measured in an air atmosphere. Extreme care was used to prevent large amplitude droplet vibrations and surface wetting; therefore, these data can be compared to film boiling theory. For these data, diffusion from the upper surface of the drop is a dominant mode of mass transfer from the drop. A closed-form analytical film boiling theory is developed to account for the diffusive evaporation. Reasonable agreement between data and theory is seen.
Vapor deposition of thin films
A highly pure thin metal film having a nanocrystalline structure and a process of preparing such highly pure thin metal films of, e.g., rhodium, iridium, molybdenum, tungsten, rhenium, platinum, or palladium by plasma assisted chemical vapor deposition of, e.g., rhodium(allyl).sub.3, iridium(allyl).sub.3, molybdenum(allyl).sub.4, tungsten(allyl).sub.4, rhenium(allyl).sub.4, platinum(allyl).sub.2, or palladium(allyl).sub.2 are disclosed. Additionally, a general process of reducing the carbon content of a metallic film prepared from one or more organometallic precursor compounds by plasma assisted chemical vapor deposition is disclosed.
Smith, David C. (Los Alamos, NM); Pattillo, Stevan G. (Los Alamos, NM); Laia, Jr., Joseph R. (Los Alamos, NM); Sattelberger, Alfred P. (Los Alamos, NM)
Leemann, B.T.; Yourd, R.B.
Film thickness and roughness of ZDDP antiwear films
The two experimental techniques, spacer layer interferometry imaging (SLIM) and atomic force microscopy (AFM), have been used\\u000a to measure the thickness and roughness of zinc dialkyl dithiophosphate (ZDDP) reaction films formed in a rolling-sliding minitraction\\u000a machine (MTM) tribometer. The AFM method has been complemented by a novel ZDDP film removal method based on ethylenediaminetetraacetic\\u000a acid (EDTA) solution. It has been
Ksenija Topolovec-Miklozic; T. Reg Forbus; Hugh A. Spikes
Thin film characterization using spectroscopic ellipsometry
The application of the multiple angle and wavelength (MAW) technique to measure the dielectric function of semiconducting films is discussed. This technique evaluates unambiguously the complex dielectric function, epsilon (E), of the film without any pre-assumptions. In some cases the effective medium approximation (EMA) was used to determine the volume fraction of the film components. Application of the MAW technique to several semiconducting films was published previously. Different applications and examples are given, including metal and insulator films.
Alterovitz, Samuel A.
Testing Bonds Between Brittle And Ductile Films
Simple uniaxial strain test devised to measure intrinsic shear strength. Brittle film deposited on ductile stubstrate film, and combination stretched until brittle film cracks, then separates from substrate. Dimensions of cracked segments related in known way to tensile strength of brittle film and shear strength of bond between two films. Despite approximations and limitations of technique, tests show it yields semiquantitative measures of bond strengths, independent of mechanical properties of substrates, with results reproducible with plus or minus 6 percent.
Wheeler, Donald R.; Ohsaki, Hiroyuki
Cellulose triacetate, thin film dielectric capacitor
Very thin films of cellulose triacetate are cast from a solution containing a small amount of high boiling temperature, non-solvent which evaporates last and lifts the film from the casting surface. Stretched, oriented, crystallized films have high electrical breakdown properties. Metallized films less than about 2 microns in thickness form self-healing electrodes for high energy density, pulsed power capacitors. Thicker films can be utilized as a dielectric for a capacitor.
Yen, Shiao-Ping S. (inventor); Jow, T. Richard (inventor)
Polyvinylpyrrolidone oral films of enrofloxacin: Film characterization and drug release.
Enrofloxacin is a fluoroquinolone derivative used for treating urinary tract, respiratory and skin infections in animals. However, low solubility and low bioavailability prevented it from using on humans. Polyvinylpyrrolidone (PVP) is an inert, non toxic polymer with excellent hydrophilic properties, besides it can enhance bioavailability by forming drug polymer conjugates. With the aim of increasing solubility and bioavailability, enrofloxacin thin films were prepared using PVP as a polymer matrix. The obtained oral thin films exhibited excellent uniformity and mechanical properties. Swelling properties of the oral thin films revealed that the water uptake was enhanced by 21%. The surface pH has been found to be 6.8�0.1 indicating that these films will not cause any irritation to oral mucosa. FTIR data of the oral thin films indicated physical interaction between drug and polymer. SEM analysis revealed uniform distribution of drug in polymer matrix. In vitro drug release profiles showed enhanced release profiles (which are also pH dependant) for thin films compared to pure drug. Antibacterial activity was found to be dose dependent and maximum susceptibility was found on Klebsiella pneumonia making this preparation more suitable for respiratory infections. PMID:24858388
Kumar, G Prem; Phani, A R; Prasad, R G S V; Sanganal, Jagadeesh S; Manali, N; Gupta, R; Rashmi, N; Prabhakara, G S; Salins, C Paul; Sandeep, K; Raju, D B
Lire un film: Mode d'emploi (Reading a Film: Directions for Use).
A film appreciation exercise for use in the foreign language class is outlined. The questions involve analysis of viewer reactions, film characteristics, visual and aural production specifications, and other technical aspects of the film. (MSE)
Perret, Jacques
PTFE films with improved flexibility
Development and application of flexible polytetrafluroethylene films for expulsion bladders in spacecraft propellant tanks are described. Flexibility of material is obtained by reducing crystallinity through annealing and quenching in water. Physical and mechanical properties of material are presented.
Muraca, R. F.; Koch, A. A.
The computer program described not only allows the user to determine rental sources for a particular film title quickly, but also to select the least expensive of the sources. This program developed at SUNY Cortland's Sperry Learning Resources Center and ...
C. V. Minnella
Metallo-organic decomposition films
A summary of metallo-organic deposition (MOD) films for solar cells was presented. The MOD materials are metal ions compounded with organic radicals. The technology is evolving quickly for solar cell metallization. Silver compounds, especially silver neodecanoate, were developed which can be applied by thick-film screening, ink-jet printing, spin-on, spray, or dip methods. Some of the advantages of MOD are: high uniform metal content, lower firing temperatures, decomposition without leaving a carbon deposit or toxic materials, and a film that is stable under ambient conditions. Molecular design criteria were explained along with compounds formulated to date, and the accompanying reactions for these compounds. Phase stability and the other experimental and analytic results of MOD films were presented.
Gallagher, B. D.
Boron doped nanostructured diamond films
A chemical vapor deposition hydrogen/methane/nitrogen feed-gas mixture with unconventionally high methane (15% CH4 by volume) normally used to grow ultra-hard and smooth nanostructured diamond films on Ti-6Al-4V alloy substrates was modified to include diborane B2H6 for boron-doping of diamond films. The flow rates for B2H 6 and N2 were varied to investigate their effect on plasma chemistry, film structure, boron incorporation, and mechanical properties. It was found that boron atoms can easily be incorporated into diamond films and change the lattice constant and film structure. Nitrogen, on the other hand, competes with boron in the plasma and acts to prevent boron incorporation into the diamond structure. In addition, with the appropriate choice of deposition conditions, the film structure can be tailored to range from highly crystalline, well faceted diamond to nanocrystalline diamond. Glancing angle X-ray diffraction and Micro-Raman were used as the main tools to investigate the relation between processing and structure. An optimal N2/CH4 ratio of 0.4 was found to result in a film with a minimum in grain size and surface roughness, along with high boron incorporation (�4 x 1020 cm-3). Mechanical properties and thermal stability of boron doped nanostructured diamond films were examined by means of nanoindentation, open air thermal annealing, and nanotribometry. It was found that the films have high hardness close to that of undoped nanostructured diamond films. Thermal stability of these films was evaluated by heating in an oxygen environment above 700�C. Improved thermal stability of boron doped nanostructured diamond films was observed. Tribological tests show that although both undoped and boron doped nanostructured diamond films show extremely low coefficient of friction and wear rate as compared with uncoated titanium alloys (Ti-6Al-4V) and cobalt chrome alloy (Co-Cr-Mo), a critical failure max stress of 2.2 GPa was observed for boron doped nanostructured diamond films. A FORTRAN Chemical Kinetics Package for the Analysis of Gas Phase Chemical Kinetics, gas-phase thermodynamic equilibrium calculations involving H 2/CH4/N2/B2H6 mixtures was employed to investigate the chemical interactions leading to boron incorporation and crystalline structure variations. The strong influence of the BH 3 in causing the boron incorporation and the role of CN radical in causing the nanocrystallinity are confirmed by the correlation of their modeled compositions in the gas phase with boron content and degree of nanocrystallinity as determined experimentally. A good degree of agreement was obtained between the theoretically predicted gas phase concentration of species and the experimental concentration trends as measured by the optical emission spectroscopy of the microwave plasma. Overall, high film hardness and toughness, combined with good thermal stability and low surface roughness, indicate that nanostructured boron doped diamond films can be used as wear resistant coatings that are able to withstand high temperature oxidizing environments.
Liang, Qi
Modified Film Holder for Endodontics.
Proper film positioning and stabilization in spite of projecting instruments, rubber dam clamps, and frame have always been a challenge, particularly for students and assistants using the long cone, paralleling technique. Simple modifications to the new, ...
O. E. Paquette R. O. Segall C. E. del Rio
Thin-Film Phase Shifters.
This work has concentrated on developing thin-film tunable dielectric technology towards commercial viability for phase-shifters. Agile's varactor and phase shifter modeling has demonstrated the potential for this technology to provide low loss phase shif...
C. Elsass
Interference Colors in Thin Films.
Explains interference colors in thin films as being due to the removal, or considerable reduction, of a certain color by destructive inteference that results in the complementary color being seen. (GA)
Armstrong, H. L.
Antistatic additive for polyimide films
Thin polyimide films are given excellent antistatic properties even at high temperature by low-level loading with lithium salts. Extremely hygroscopic, these salts absorb a layer of atmospheric water that provides conductive paths allowing charges to dissipate.
Sarbolouki, M. N.
The thin film microwave iris
Development of waveguide iris for microwave coupling applications using thin film techniques is discussed. Production process and installation of iris are described. Iris improves power transmission properties of waveguide window.
Ramey, R. L.; Landes, H. S.; Manus, E. A.
Titanium Dioxide Active Film Devices.
Laboratory models of thin film diodes with the Ti-TiO2-Ag configuration were developed and their characteristics studied. High static rectification ratios were obtained on specimens made under reproducible conditions. The functional dependence of current ...
T. K. Lakshmanan W. C. Peterson R. L. Peterson
PBS 2013 Online Film Festival
Have you ever wanted to attend a film festival from the comfort of your own living room? With this collection of 25 short films under the PBS banner, that dream can become a reality. The films are featured under the headline "Watch Us Surprise You," which is a worthy byline. New visitors should start by watching the introduction to the history of online video and then looking over the About the Festival area. Here they can watch a one-minute introduction to the festival and then they should dive right in. The films here include an exploration of anagrams ("Ars Magna"), a look into the life of a disappearing cat ("CatCam"), and a piece on shell mounds in California titled "Injunuity: Buried." Overall, it's a wonderful collection that will inspire filmmakers young and old to get out there and craft their own narrative work.
Applications of film thickness equations
A number of applications of elastohydrodynamic film thickness expressions were considered. The motion of a steel ball over steel surfaces presenting varying degrees of conformity was examined. The equation for minimum film thickness in elliptical conjunctions under elastohydrodynamic conditions was applied to roller and ball bearings. An involute gear was also introduced, it was again found that the elliptical conjunction expression yielded a conservative estimate of the minimum film thickness. Continuously variable-speed drives like the Perbury gear, which present truly elliptical elastohydrodynamic conjunctions, are favored increasingly in mobile and static machinery. A representative elastohydrodynamic condition for this class of machinery is considered for power transmission equipment. The possibility of elastohydrodynamic films of water or oil forming between locomotive wheels and rails is examined. The important subject of traction on the railways is attracting considerable attention in various countries at the present time. The final example of a synovial joint introduced the equation developed for isoviscous-elastic regimes of lubrication.
Hamrock, B. J.; Dowson, D.
Hygroscopic Expansion of Polyester Films
The hygroscopic expansion of polyethylene terephthalate (PET) and polyethylene 2,6-naphthalate (PEN) films was measured by use of a thermomechanical analyzer at 30, 40 or 50�C. Their initial weight increase was proportional to the square root of time after exposure to moisture, obeying Fick�s law; the hygroscopic expansion with time showed the same relationship. The equilibrium moisture content was 1.0� 10-5/% RH for both films; the hygroscopic expansion at equilibrium was also about the same for these films. However, the diffusion constant for moisture in PEN films was 1\\cdot6� 10-9 cm2/s at 30�C in comparison with 4\\cdot8� 10-8 for PET, although the activation energies were 45 kJ/mol for PET and 41 for PEN.
Ouchi, Isuke; Hosoi, Masahiro; Tomie, Takashi