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Amorphous Silicon(a-Si: H) Thin Film Based Omnidirectional Control Solar Powered Vehicle
Science Conference Proceedings (OSTI)
Through the paper, our goal is to drive a car with the help of thin film based solar cell. Mechanical and Electrical parts are assembled thereby. The main objective of this project is to collect maximum solar energy from the solar spectrum and use that ... Keywords: Thin film Photovoltaic, Single p-i-n Junction, Steering Mechanism, H-Bridge, Gear motor
Abdullah Moinuddin; Md. Jahidul Hoque; Jony C. Sarker; Akhter Zia
Solar Control Thin Films Laboratory
NLE Websites -- All DOE Office Websites (Extended Search)
Sputtering equipment Solar Control Thin Films Laboratory The Solar Control Thin Films lab develops novel thin film coatings, deposition technologies, and device systems for...
High efficiency thin film CdTe and a-Si based solar cells
DOE Green Energy (OSTI)
This report describes work done by the University of Toledo during the first year of this subcontract. During this time, the CdTe group constructed a second dual magnetron sputter deposition facility; optimized reactive sputtering for ZnTe:N films to achieve 10 ohm-cm resistivity and {approximately}9% efficiency cells with a copper-free ZnTe:N/Ni contact; identified Cu-related photoluminescence features and studied their correlation with cell performance including their dependence on temperature and E-fields; studied band-tail absorption in CdS{sub x}Te{sub 1{minus}x} films at 10 K and 300 K; collaborated with the National CdTe PV Team on (1) studies of high-resistivity tin oxide (HRT) layers from ITN Energy Systems, (2) fabrication of cells on the HRT layers with 0, 300, and 800-nm CdS, and (3) preparation of ZnTe:N-based contacts on First Solar materials for stress testing; and collaborated with Brooklyn College for ellipsometry studies of CdS{sub x}Te{sub 1{minus}x} alloy films, and with the University of Buffalo/Brookhaven NSLS for synchrotron X-ray fluorescence studies of interdiffusion in CdS/CdTe bilayers. The a-Si group established a baseline for fabricating a-Si-based solar cells with single, tandem, and triple-junction structures; fabricated a-Si/a-SiGe/a-SiGe triple-junction solar cells with an initial efficiency of 9.7% during the second quarter, and 10.6% during the fourth quarter (after 1166 hours of light-soaking under 1-sun light intensity at 50 C, the 10.6% solar cells stabilized at about 9%); fabricated wide-bandgap a-Si top cells, the highest Voc achieved for the single-junction top cell was 1.02 V, and top cells with high FF (up to 74%) were fabricated routinely; fabricated high-quality narrow-bandgap a-SiGe solar cells with 8.3% efficiency; found that bandgap-graded buffer layers improve the performance (Voc and FF) of the narrow-bandgap a-SiGe bottom cells; and found that a small amount of oxygen partial pressure ({approximately}2 {times} 10{sup {minus}5} torr) was beneficial for growing high-quality films from ITO targets.
Compaan, A. D.; Deng, X.; Bohn, R. G.
High Efficiency Thin Film CdTe and a-Si Based Solar Cells: Final Technical Report, 4 March 1998--15 October 2001
This is the final report covering about 42 months of this subcontract for research on high-efficiency CdTe-based thin-film solar cells and on high-efficiency a-Si-based thin-film solar cells. Phases I and II have been extensively covered in two Annual Reports. For this Final Report, highlights of the first two Phases will be provided and then detail will be given on the last year and a half of Phase III. The effort on CdTe-based materials is led by Prof. Compaan and emphasizes the use of sputter deposition of the semiconductor layers in the fabrication of CdS/CdTe cells. The effort on high-efficiency a-Si materials is led by Prof. Deng and emphasizes plasma-enhanced chemical vapor deposition for cell fabrication with major efforts on triple-junction devices.
Thin Film Solar Technologies | Open Energy Information
Open Energy Info (EERE)
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Solar photovoltaic technology: The thin film option
Photovoltaics (PV) the direct conversion of sunlight to electricity was first discovered by scientists at the Bell Labs in 1954. In the late 1960's and 1970's most of the solar cell technology has been used for space applications to power satellites. The main work horse for the PV technology has been crystalline silicon (Si) solar cells. Over the past 15 years this has led to cost reduction from $35/kWh to about $0.30/kWh at the present time. Demonstrated reliability of 20 years or more has resulted in acceptance by several utilities. However, cost reductions in crystalline Si solar cells have been limited by the cost of wafering of ingots and the attendant loss of material. A number of Si sheet solar cells are also being investigated. In the past decade the emphasis of the research and development effort has been focused on thin film solar cells, which have the potential for generating power at much lower cost of $1-2/Wp. Thin film solar cells that are presently being investigated and are generating global attention are: amorphous silicon (a-Si:H), cadmium telluride (CdTe), and copper indium diselenide (CuInSe/sub 2,/ or CIS). In the past few years, considerable progress has been; made by all three of these thin film solar cells. This paper reviews the current status and future potential of these exiting thin film solar cell technologies.
Ullal, H.S.; Zweibel, K.; Sabisky, E.S.; Surek, T.
Overview and Challenges of Thin Film Solar Electric Technologies
In this paper, we report on the significant progress made worldwide by thin-film solar cells, namely, amorphous silicon (a-Si), cadmium telluride (CdTe), and copper indium gallium diselenide (CIGS). Thin-film photovoltaic (PV) technology status is also discussed in detail. In addition, R&D and technology challenges in all three areas are elucidated. The worldwide estimated projection for thin-film PV technology production capacity announcements are estimated at more than 5000 MW by 2010.
Ullal, H. S.
Thin film solar energy collector
DOE Patents (OSTI)
A multi-layer solar energy collector of improved stability comprising: (1) a substrate of quartz, silicate glass, stainless steel or aluminum-containing ferritic alloy; (2) a solar absorptive layer comprising silver, copper oxide, rhodium/rhodium oxide and 0-15% by weight of platinum; (3) an interlayer comprising silver or silver/platinum; and (4) an optional external anti-reflective coating, plus a method for preparing a thermally stable multi-layered solar collector, in which the absorptive layer is undercoated with a thin film of silver or silver/platinum to obtain an improved conductor-dielectric tandem.
Aykan, Kamran (Monmouth Beach, NJ); Farrauto, Robert J. (Westfield, NJ); Jefferson, Clinton F. (Millburn, NJ); Lanam, Richard D. (Westfield, NJ)
Thin film absorber for a solar collector
SciTech Connect
This invention pertains to energy absorbers for solar collectors, and more particularly to high performance thin film absorbers. The solar collectors comprising the absorber of this invention overcome several problems seen in current systems, such as excessive hardware, high cost and unreliability. In the preferred form, the apparatus features a substantially rigid planar frame with a thin film window bonded to one planar side of the frame. An absorber in accordance with the present invention is comprised of two thin film layers that are sealed perimetrically. In a preferred embodiment, thin film layers are formed from a metal/plastic laminate. The layers define a fluid-tight planar envelope of large surface area to volume through which a heat transfer fluid flows. The absorber is bonded to the other planar side of the frame. The thin film construction of the absorber assures substantially full envelope wetting and thus good efficiency. The window and absorber films stress the frame adding to the overall strength of the collector.
Wilhelm, William G. (Cutchogue, NY)
A survey of thin-film solar photovoltaic industry & technologies
E-Print Network (OSTI)
A new type of solar cell technology using so-called thin-film solar photovoltaic material has the potential to make a great impact on our lives. Because it uses very little or no silicon at all, thin- film (TF) solar ...
Grama, Sorin
Hot-Wire Deposition of Hydrogenated Nanocrystalline SiGe Films for Thin-Film Si Based Solar Cells
Hot-Wire Deposition of Hydrogenated Nanocrystalline SiGe Films for Thin-Film Si Based Solar Cells bandgap absorber in an a-Si/a-SiGe/nc-SiGe(nc- Si) triple-junction solar cell due to its higher optical investigations of nc-SiGe:H thin films made by hot-wire chemical vapor deposition (HWCVD) with a coil
Deng, Xunming
Polycrystalline Thin Film Solar Cell Technologies: Preprint
Rapid progress is being made by CdTe and CIGS-based thin-film PV technologies in entering commercial markets.
Efficient light trapping structure in thin film silicon solar cells
Thin film silicon solar cells are believed to be promising candidates for continuing cost reduction in photovoltaic panels because silicon usage could be greatly reduced. Since silicon is an indirect bandgap semiconductor, ...
Sheng, Xing
Recent technological advances in thin film solar cells
High-efficiency, low-cost thin film solar cells are an exciting photovoltaic technology option for generating cost-effective electricity in 1995 and beyond. This paper reviews the substantial advances made by several thin film solar cell technologies, namely, amorphous silicon, copper indium diselenide, cadmium telluride, and polycrystalline silicon. Recent examples of utility demonstration projects of these emerging materials are also discussed. 8 refs., 4 figs.
Ullal, H.S.; Zwelbel, K.; Surek, T.
Polycrystalline Thin-Film Multijunction Solar Cells
We present a digest of our research on the thin-film material components that comprise the top and bottom cells of three different material systems and the tandem devices constructed from them.
Noufi, R.; Wu, X.; Abu-Shama, J.; Ramanathan, K; Dhere, R.; Zhou, J.; Coutts, T.; Contreras, M.; Gessert, T.; Ward, J. S.
Thin-film absorber for a solar collector
Wilhelm, W.G.
Processing and modeling issues for thin-film solar cell devices. Final report
During the third phase of the subcontract, IEC researchers have continued to provide the thin film PV community with greater depth of understanding and insight into a wide variety of issues including: the deposition and characterization of CuIn{sub 1-x}Ga{sub x}Se{sub 2}, a-Si, CdTe, CdS, and TCO thin films; the relationships between film and device properties; and the processing and analysis of thin film PV devices. This has been achieved through the systematic investigation of all aspects of film and device production and through the analysis and quantification of the reaction chemistries involved in thin film deposition. This methodology has led to controlled fabrications of 15% efficient CuIn{sub 1-x}Ga{sub x}Se{sub 2} solar cells over a wide range of Ga compositions, improved process control of the fabrication of 10% efficient a-Si solar cells, and reliable and generally applicable procedures for both contacting and doping films. Additional accomplishments are listed below.
Birkmire, R.W.; Phillips, J.E. [Univ. of Delaware, Newark, DE (United States). Institute of Energy Conversion
Polycrystalline thin-film solar cells and modules
This paper describes the recent technological advances in polycrystalline thin-film solar cells and modules. Three thin film materials, namely, cadmium telluride (CdTe), copper indium diselenide (CuInSe{sub 2}, CIS) and silicon films (Si-films) have made substantial technical progress, both in device and module performance. Early stability results for modules tested outdoors by various groups worldwide are also encouraging. The major global players actively involved in the development of the these technologies are discussed. Technical issues related to these materials are elucidated. Three 20-kW polycrystalline thin-film demonstration photovoltaic (PV) systems are expected to be installed in Davis, CA in 1992 as part of the Photovoltaics for Utility-Scale Applications (PVUSA) project. This is a joint project between the US Department of Energy (DOE), Pacific Gas and Electric (PG&E), Electric Power Research Institute (EPRI), California Energy Commission (CEC), and a utility consortium.
Ullal, H.S.; Stone, J.L.; Zweibel, K.; Surek, T.; Mitchell, R.L.
This paper describes the recent technological advances in polycrystalline thin-film solar cells and modules. Three thin film materials, namely, cadmium telluride (CdTe), copper indium diselenide (CuInSe{sub 2}, CIS) and silicon films (Si-films) have made substantial technical progress, both in device and module performance. Early stability results for modules tested outdoors by various groups worldwide are also encouraging. The major global players actively involved in the development of the these technologies are discussed. Technical issues related to these materials are elucidated. Three 20-kW polycrystalline thin-film demonstration photovoltaic (PV) systems are expected to be installed in Davis, CA in 1992 as part of the Photovoltaics for Utility-Scale Applications (PVUSA) project. This is a joint project between the US Department of Energy (DOE), Pacific Gas and Electric (PG E), Electric Power Research Institute (EPRI), California Energy Commission (CEC), and a utility consortium.
Identification, Characterization, and Implications of Shadow Degradation in Thin Film Solar Cells
that the SD is a generic reliability concern for all thin film PV technologies, however, in this paper we, USA Abstract-- We describe a comprehensive study of intrinsic reliability issue arising from partial reliability concern for thin film solar cell. Keywords Thin film solar cells, voltage stress, performance
Alam, Muhammad A.
High efficiency thin film silicon solar cells with novel light trapping : principle, design and processing
One major efficiency limiting factor in thin film solar cells is weak absorption of long wavelength photons due to the limited optical path length imposed by the thin film thickness. This is especially severe in Si because ...
Zeng, Lirong, Ph. D. Massachusetts Institute of Technology
Junction Evolution During Fabrication of CdS/CdTe Thin-film PV Solar Cells (Presentation)
Discussion of the formation of CdTe thin-film PV junctions and optimization of CdTe thin-film PV solar cells.
Gessert, T. A.
Thin film transistors and solar cells. (Latest citations from the US Patent bibliographic file with exemplary claims). Published Search
The bibliography contains citations of selected patents concerning the fabrication and application methods of thin film transistors and thin film solar cells. Methods of manufacturing thin film transistors for use in electronic display devices are presented. Techniques for continuously producing durable and reliable thin film solar cells are discussed. (Contains 250 citations and includes a subject term index and title list.)
Thin film transistors and solar cells. (Latest citations from the US Patent Bibliographic File with Exemplary Claims). Published Search
Not Available
Thin film solar cell including a spatially modulated intrinsic layer
One or more thin film solar cells in which the intrinsic layer of substantially amorphous semiconductor alloy material thereof includes at least a first band gap portion and a narrower band gap portion. The band gap of the intrinsic layer is spatially graded through a portion of the bulk thickness, said graded portion including a region removed from the intrinsic layer-dopant layer interfaces. The band gap of the intrinsic layer is always less than the band gap of the doped layers. The gradation of the intrinsic layer is effected such that the open circuit voltage and/or the fill factor of the one or plural solar cell structure is enhanced.
Guha, Subhendu (Troy, MI); Yang, Chi-Chung (Troy, MI); Ovshinsky, Stanford R. (Bloomfield Hills, MI)
Thin film polycrystalline silicon solar cells
During the present quarter efficiency of heterostructure solar cells has been increased from 13 to 13.7% for single crystal and from 10.3 to 11.2% for polysilicon. For polysilicon the improvements can be attributed to reductions in grid-area coverage and in reflection losses and for single crystal to a combination of reduction in grid-area coverage and increase in fill factor. The heterostructure cells in both cases were IT0/n-Si solar cells. Degradation in Sn0/sub 2//n-Si solar cells can be greatly reduced to negligible proportions by proper encapsulation. The cells used in stability tests have an average initial efficiency of 11% which reduces to a value of about 10.5% after 6 months of exposure to sunlight and ambient conditions. This small degradation occurs within the first month, and the efficiency remains constant subsequently. The reduction in efficiency is due to a decrease in the open-circuit voltage only, while the short-circuit current and fill factor remain constant. The effects of grain-size on the Hall measurements in polysilicon have been analyzed and interpreted, with some modifications, using a model proposed by Bube. This modified model predicts that the measured effective Hall voltage is composed of components originating from the bulk and space-charge region. For materials with large grains, the carrier concentration is independent of the inter-grain boundary barrier, whereas the mobility is dependent on it. However, for small rains, both the carrier density and mobility depend on the barrier. These predictions are consistant with experimental results of mm-size Wacker polysilicon and ..mu..m-size NTD polysilicon.
Ghosh, A. K.; Feng, T.; Eustace, D. J.; Maruska, H. P.
Polycrystalline Thin Film Photovoltaics: From the Laboratory to Solar Fields; Preprint
We review the status of commercial polycrystalline thin-film solar cells and photovoltaic (PV) modules, including current and projected commercialization activities.
von Roedern, B.; Ullal, H. S.; Zweibel, K.
Solar Thin Films Inc formerly American United Global Inc | Open Energy
Films Inc formerly American United Global Inc Films Inc formerly American United Global Inc Jump to: navigation, search Name Solar Thin Films Inc (formerly American United Global Inc) Place New York, New York Zip 10038 Sector Solar Product A US-based solar manufacturing equipment supplier. References Solar Thin Films Inc (formerly American United Global Inc)[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. Solar Thin Films Inc (formerly American United Global Inc) is a company located in New York, New York . References ↑ "Solar Thin Films Inc (formerly American United Global Inc)" Retrieved from "http://en.openei.org/w/index.php?title=Solar_Thin_Films_Inc_formerly_American_United_Global_Inc&oldid=351338
Tax Credits Give Thin-Film Solar a Big Boost | Department of...
Energy.gov (U.S. Department of Energy (DOE)) Indexed Site
Solar a Big Boost October 18, 2010 - 2:00pm Addthis MiaSol will expand its capacity to make its thin-film solar panels by more than ten times, thanks to two Recovery Act...
and Challenges of Thin and Challenges of Thin Film Solar Electric Technologies H.S. Ullal Presented at the World Renewable Energy Congress X and Exhibition 2008 Glasgow, Scotland, United Kingdom July 19-25, 2008 Conference Paper NREL/CP-520-43355 December 2008 NOTICE The submitted manuscript has been offered by an employee of the Alliance for Sustainable Energy, LLC (ASE), a contractor of the US Government under Contract No. DE-AC36-08-GO28308. Accordingly, the US Government and ASE retain a nonexclusive royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for US Government purposes. This report was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor any agency thereof, nor any of their employees, makes any
THE PERFORMANCE OF THIN FILM SOLAR CELLS EMPLOYING PHOTOVOLTAIC Cu22014x Te-CdTe HETEROJUNCTIONS (1)
195 THE PERFORMANCE OF THIN FILM SOLAR CELLS EMPLOYING PHOTOVOLTAIC Cu22014x Te This paper is a short status report on the continuing development of Cu22014xTe-CdTe thin film solar cells thin film work. The most pressing current need is to determine how to extend cell life, particularly
Paris-Sud XI, Université de
New GE Plant to Produce Thin Film PV Solar Panels Based on NREL Technology
New GE Plant to Produce Thin Film PV Solar Panels Based on NREL New GE Plant to Produce Thin Film PV Solar Panels Based on NREL Technology New GE Plant to Produce Thin Film PV Solar Panels Based on NREL Technology April 22, 2011 - 10:17am Addthis Photo courtesy of General Electric Photo courtesy of General Electric Minh Le Minh Le Program Manager, Solar Program Earlier this month, General Electric announced plans to enter the global marketplace for solar photovoltaic (PV) panels in a big way - and to do it, they will be using technology pioneered at the Department of Energy's National Renewable Energy Lab (NREL). The record-breaking Cadmium-Telluride (CdTe) thin film photovoltaic technology GE has chosen for its solar panels was originally developed more than a decade ago by a team of scientists led by NREL's Xuanzhi Wu, and
The bibliography contains citations of selected patents concerning the fabrication and application methods of thin film transistors and thin film solar cells. Methods of manufacturing thin film transistors for use in electronic display devices are presented. Techniques for continuously producing durable and reliable thin film solar cells are discussed. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)
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.
Processing and modeling issues for thin-film solar cell devices. Annual subcontract report, January 16, 1993--January 15, 1994
The overall objective of the research presented in this report is to advance the development and acceptance of thin-film photovoltaic modules by increasing the understanding of film growth and processing and its relationship to materials properties and solar cell performance. The specific means toward meeting this larger goal include: (1) investigating scalable, cost-effective deposition processes; (2) preparing thin-film materials and device layers and completed cell structures; (3) performing detailed material and device analysis; and (4) participating in collaborative research efforts that address the needs of PV-manufacturers. These objectives are being pursued with CuInSe{sub 2}, CdTe and a-Si based solar cells.
Birkmire, R.W.; Phillips, J.E.; Buchanan, W.A.; Hegedus, S.S.; McCandless, B.E.; Shafarman, W.N.; Yokimcus, T.A. [Institute of Energy Conversion, Newark, DE (United States)
Integrated photonic structures for light trapping in thin-film Si solar cells
We explore the mechanisms for an efficient light trapping structure for thin-film silicon solar cells. The design combines a distributed Bragg reflector (DBR) and periodic gratings. Using photonic band theories and numerical ...
Technological assessment of light-trapping technology for thin-film Si solar cell
The proposed light trapping technology of Distributed Bragg Reflector (DBR) with Diffraction Grating (DG) and Anti-Reflection Coating (ARC) for thin film Si solar cell was analyzed from the technology, market, and ...
Susantyoko, Rahmat Agung
Earth abundant materials for high efficiency heterojunction thin film solar cells
We investigate earth abundant materials for thin-film solar cells that can meet tens of terawatts level deployment potential. Candidate materials are identified by combinatorial search, large-scale electronic structure ...
Buonassisi, Tonio
Advances in thin-film solar cells for lightweight space photovoltaic power
The present stature and current research directions of photovoltaic arrays as primary power systems for space are reviewed. There have recently been great advances in the technology of thin-film solar cells for terrestrial applications. In a thin-film solar cell the thickness of the active element is only a few microns; transfer of this technology to space arrays could result in ultralow-weight solar arrays with potentially large gains in specific power. Recent advances in thin-film solar cells are reviewed, including polycrystalline copper-indium selenide (CuInSe2) and related I-III-VI2 compounds, polycrystalline cadmium telluride and related II-VI compounds, and amorphous silicon:hydrogen and alloys. The best experimental efficiency on thin-film solar cells to date is 12 percent AMO for CuInSe2. This efficiency is likely to be increased in the next few years. The radiation tolerance of thin-film materials is far greater than that of single-crystal materials. CuInSe2 shows no degradation when exposed to 1 MeV electrons. Experimental evidence also suggests that most of all of the radiation damage on thin-films can be removed by a low temperature anneal. The possibility of thin-film multibandgap cascade solar cells is discussed, including the tradeoffs between monolithic and mechanically stacked cells. The best current efficiency for a cascade is 12.5 percent AMO for an amorphous silicon on CuInSe2 multibandgap combination. Higher efficiencies are expected in the future. For several missions, including solar-electric propulsion, a manned Mars mission, and lunar exploration and manufacturing, thin-film photovolatic arrays may be a mission-enabling technology.
Landis, G.A.; Bailey, S.G.; Flood, D.J.
Polycrystalline Thin Film Photovoltaics: From the Laboratory to Solar Fields (Presentation)
The conclusions of this report are that: (1) many issues how thin-film solar cells work remain unresolved, requiring further fundamental R and D effort; (2) commercial thin-film PV module production reached 29% in 2005 in the US, indicating much more rapid growth than crystalline Si PV; (3) commercial module performance is increasing based on current knowledge, more R and D will lead to further improvement; and (4) stability of thin-film modules is acceptable ({le} 1% per year power loss) if the right manufacturing processes are used for manufacturing.
von Roedern, B.; Ullal, H.; Zweibel, K.
Rapid Deposition Technology Holds the Key for the World's Largest Manufacturer of Thin-Film Solar Modules (Fact Sheet)
First Solar, Inc. has been collaborating with NREL since 1991, advancing its thin-film cadmium telluride solar technology to grow from a startup company to become one of the world's largest manufacturers of solar modules, and the world's largest manufacturer of thin-film solar modules.
Tax Credits Give Thin-Film Solar a Big Boost | Department of Energy
Tax Credits Give Thin-Film Solar a Big Boost Tax Credits Give Thin-Film Solar a Big Boost Tax Credits Give Thin-Film Solar a Big Boost October 18, 2010 - 2:00pm Addthis MiaSolé will expand its capacity to make its thin-film solar panels by more than ten times, thanks to two Recovery Act tax credits.| Photo courtesy of MiaSolé MiaSolé will expand its capacity to make its thin-film solar panels by more than ten times, thanks to two Recovery Act tax credits.| Photo courtesy of MiaSolé Lorelei Laird Writer, Energy Empowers What are the key facts? MiaSolé adding more than ten times its current manufacturing capacity Company expects to double or triple its workforce with expansion Expansion is funded by $101 million in Recovery Act tax credit For MiaSolé, a relative newcomer to the solar energy market, 2010 has been
Processing and modeling issues for thin-film solar cell devices: Annual subcontract report, January 16, 1995 -- January 15, 1996
The overall mission of the Institute of Energy Conversion is the development of thin film photovoltaic cells, modules, and related manufacturing technology and the education of students and professionals in photovoltaic technology. The objectives of this four-year NREL subcontract are to advance the state of the art and the acceptance of thin film PV modules in the areas of improved technology for thin film deposition, device fabrication, and material and device characterization and modeling, relating to solar cells based on CuInSe{sub 2} and its alloys, on a-Si and its alloys, and on CdTe. In the area of CuInSe{sub 2} and its alloys, EEC researchers have produced CuIn{sub 1-x}GaxSe{sub 2} films by selenization of elemental and alloyed films with H{sub 2}Se and Se vapor and by a wide variety of process variations employing co-evaporation of the elements. Careful design, execution and analysis of these experiments has led to an improved understanding of the reaction chemistry involved, including estimations of the reaction rate constants. Investigation of device fabrication has also included studies of the processing of the Mo, US and ZnO deposition parameters and their influence on device properties. An indication of the success of these procedures was the fabrication of a 15% efficiency CuIn{sub 1-x}GaxSe{sub 2} solar cell.
Birkmire, R.W.; Phillips, J.E.; Buchanan, W.A.; Eser, E.; Hegedus, S.S.; McCandless, B.E.; Meyers, P.V.; Shafarman, W.N. [Univ. of Delaware, Newark, DE (United States)
Electron energy-loss spectroscopy of boron-doped layers in amorphous thin film silicon solar cells
Electron energy-loss spectroscopy of boron-doped layers in amorphous thin film silicon solar cells. de Bariloche, Argentina 3 ECN Solar Energy, High Tech Campus, Building 5, 5656 AE Eindhoven energy-loss spectroscopy (EELS) is used to study p-doped layers in n-i-p amorphous thin film Si solar
Dunin-Borkowski, Rafal E.
Enhanced Efficiency of Light-Trapping Nanoantenna Arrays for Thin Film Solar Cells
We suggest a novel concept of efficient light-trapping structures for thin-film solar cells based on arrays of planar nanoantennas operating far from plasmonic resonances. The operation principle of our structures relies on the excitation of chessboard-like collective modes of the nanoantenna arrays with the field localized between the neighboring metal elements. We demonstrated theoretically substantial enhancement of solar-cell short-circuit current by the designed light-trapping structure in the whole spectrum range of the solar-cell operation compared to conventional structures employing anti-reflecting coating. Our approach provides a general background for a design of different types of efficient broadband light-trapping structures for thin-film solar-cell technologically compatible with large-area thin-film fabrication techniques.
Simovski, Constantin R; Voroshilov, Pavel M; Guzhva, Michael E; Belov, Pavel A; Kivshar, Yuri S
p-Doping limit and donor compensation in CdTe polycrystalline thin film solar cells
everything accelerates. ARCO solar produces more than 1 MW PV cells in `80, being the first in the world, the Million Solar Roofs in the US, and many more. Besides these programs, the efficiency of CdTe thin film PV energy source is the photovoltaic (PV) cell, which converts sunlight to electrical current, without any
Bieber, Michael
NREL: Photovoltaics Research - Thin Film Photovoltaic Partnership Project
Thin Film Photovoltaic Partnership Project Thin Film Photovoltaic Partnership Project NREL's Thin Film Photovoltaic (PV) Partnership Project led R&D on emerging thin-film solar technologies in the United States from 1994 to 2009. The project made many advances in thin-film PV technologies that allowed the United States to attain world leadership in this area of solar technology. Three national R&D teams focused on thin-film semiconductor materials: amorphous silicon (a-Si), cadmium telluride (CdTe), and copper indium gallium diselenide (CIGS) and its alloys. The Module Reliability Team and Environmental Health and Safety Team were crosscutting. The teams comprised researchers from the solar industry, academia, and NREL who focused their efforts on improving materials, devices, and manufacturing processes-all
Amorphous-silicon thin-film heterojunction solar cells
The investigation of amorphous silicon materials at MTSEC has had two major thrusts: (1) to improve the amorphous material, i.e., obtain a low state density in the gap, improve the carrier collection depth and diminish non-radiative recombinations; and (2) to attempt to understand and improve on the limitations of the junction devices while evaluating the amorphous silicon materials. In the first of these efforts, the investigation has continued to examine the modifications to the a-Si(H) network by alloying silicon with other group IVA elements, either in binary or ternary compositions, and/or by replacing the hydrogenation for defect compensation with a combination of hydrogenation and alkylation or hydrogenation and halogenation. The doped junction layers are being examined in an attempt to determine the limiting characteristics of the junctions in solar cell devices of these amorphous materials. Amorphous alloys of Si-Ge, Si-C, Si-Sn were prepared as well as ternary compositions of Si-Ge-C and Si-Sn-C. In addition, Na vapor was added to the gas feed to deposit a-Si(Na, H) films, and to prepare Si-Sn, fluoride was added along with the tin by vapor additions of SnF/sub 4/ to the gas feed. The optical properties of these materials were measured, and structural and compositional information was obtained from the IR vibrational spectra using the scanning electron microscope and from analyses using scanning Auger microscopy. Electrical measurements have included the dark conductivity and the photo conductivity under room fluorescent light and at AM1 conditions. With alloys that displayed promising photoconductive properties n-i-p devices were prepared to assess the solar cell properties. Details are presented. (WHK)
Cretella, M. C.; Gregory, J. A.; Sandstrom, D. B.; Paul, W.
Improved Transparent Conducting Oxides Boost Performance of Thin-Film Solar Cells (Fact Sheet)
Today?s thin-film solar cells could not function without transparent conducting oxides (TCOs). TCOs act as a window, both protecting the cell and allowing light to pass through to the cell?s active layers. Until recently, TCOs were seen as a necessary, but static, layer of a thin-film photovoltaic (PV) cell. But a group of researchers at the National Renewable Energy Laboratory (NREL) has identified a pathway to producing improved TCO films that demonstrate higher infrared transparency. To do so, they have modified the TCOs in ways that did not seem possible a few years ago.
Status of Amorphous and Crystalline Thin Film Silicon Solar Cell Activities
This paper reviews the recent activities and accomplishments of the national Amorphous Silicon Team and a (crystalline) thin-film-Si subteam that was implemented in 2002 to research solar cell devices based on thin crystalline Si based layers. This paper reports the evolution of team organization, the technical highlights from the recent team meetings, and an outlook on commercialization potential.
von Roedern, B.
NREL Produces Highly Efficient, Wide-Bandgap, Thin-Film Solar Cells (Fact Sheet)
Researchers at the National Renewable Energy Laboratory (NREL) are finding new ways to manufacture thin-film solar cells made from copper, indium, gallium, and selenium - called CIGS cells - that are different than conventional CIGS solar cells. Their use of high-temperature glass, designed by SCHOTT AG, allows higher fabrication temperatures, opening the door to new CIGS solar cells employing light-absorbing materials with wide 'bandgaps.'
Processing and modeling issues for thin-film solar cell devices. Annual subcontract report, January 16, 1994--January 15, 1995
This report describes results achieved during the second phase of a four year subcontract to develop and understand thin film solar cell technology related to a-Si and its alloys, CuIn{sub 1{minus}x}Ga{sub x}Se{sub 2}, and CdTe. Accomplishments during this phase include, development of equations and reaction rates for the formation of CuIn{sub 1{minus}x}Ga{sub x}Se{sub 2} films by selenization, fabrication of a 15% efficient CuIn{sub 1{minus}x}Ga{sub x}Se{sub 2} cell, development of a reproducible, reliable Cu-diffused contact to CdTe, investigation of the role of CdTe-CdS interdiffusion on device operation, investigation of the substitution of HCl for CdCl{sub 2} in the post-deposition heat treatment of CdTe/CdS, demonstration of an improved reactor design for deposition of a-Si films, demonstration of improved process control in the fabrication of a ten set series of runs producing {approximately}8% efficient a-Si devices, demonstration of the utility of a simplified optical model for determining quantity and effect of current generation in each layer of a triple stacked a-Si cell, presentation of analytical and modeling procedures adapted to devices produced with each material system, presentation of baseline parameters for devices produced with each material system, and various investigations of the roles played by other layers in thin film devices including the Mo underlayer, CdS and ZnO in CuIn{sub 1{minus}x}Ga{sub x}Se{sub 2} devices, the CdS in CdTe devices, and the ZnO as window layer and as part of the back surface reflector in a-Si devices. In addition, collaborations with over ten research groups are briefly described. 73 refs., 54 figs., 34 tabs.
Birkmire, R.W.; Phillips, J.E.; Buchanan, W.A.; Hegedus, S.S.; McCandless, B.E.; Shafarman, W.N. [Delaware Univ., Newark, DE (United States). Inst. of Energy Conversion
Novel wide band gap materials for highly efficient thin film tandem solar cells
Tandem solar cells (TSCs), which use two or more materials to absorb sunlight, have achieved power conversion efficiencies of >25% versus 11-20% for commercialized single junction solar cell modules. The key to widespread commercialization of TSCs is to develop the wide-band, top solar cell that is both cheap to fabricate and has a high open-circuit voltage (i.e. >1V). Previous work in TSCs has generally focused on using expensive processing techniques with slow growth rates resulting in costs that are two orders of magnitude too expensive to be used in conventional solar cell modules. The objective of the PLANT PV proposal was to investigate the feasibility of using Ag(In,Ga)Se2 (AIGS) as the wide-bandgap absorber in the top cell of a thin film tandem solar cell (TSC). Despite being studied by very few in the solar community, AIGS solar cells have achieved one of the highest open-circuit voltages within the chalcogenide material family with a Voc of 949mV when grown with an expensive processing technique (i.e. Molecular Beam Epitaxy). PLANT PV��?s goal in Phase I of the DOE SBIR was to 1) develop the chemistry to grow AIGS thin films via solution processing techniques to reduce costs and 2) fabricate new device architectures with high open-circuit voltage to produce full tandem solar cells in Phase II. PLANT PV attempted to translate solution processing chemistries that were successful in producing >12% efficient Cu(In,Ga)Se2 solar cells by replacing copper compounds with silver. The main thrust of the research was to determine if it was possible to make high quality AIGS thin films using solution processing and to fully characterize the materials properties. PLANT PV developed several different types of silver compounds in an attempt to fabricate high quality thin films from solution. We found that silver compounds that were similar to the copper based system did not result in high quality thin films. PLANT PV was able to deposit AIGS thin films using a mixture of solution and physical vapor deposition processing, but these films lacked the p-type doping levels that are required to make decent solar cells. Over the course of the project PLANT PV was able to fabricate efficient CIGS solar cells (8.7%) but could not achieve equivalent performance using AIGS. During the nine-month grant PLANT PV set up a variety of thin film characterization tools (e.g. drive-level capacitance profiling) at the Molecular Foundry, a Department of Energy User Facility, that are now available to both industrial and academic researchers via the grant process. PLANT PV was also able to develop the back end processing of thin film solar cells at Lawrence Berkeley National Labs to achieve 8.7% efficient CIGS solar cells. This processing development will be applied to other types of thin film PV cells at the Lawrence Berkeley National Labs. While PLANT PV was able to study AIGS film growth and optoelectronic properties we concluded that AIGS produced using these methods would have a limited efficiency and would not be commercially feasible. PLANT PV did not apply for the Phase II of this grant.
Brian E. Hardin, Stephen T. Connor, Craig H. Peters
Thin film cadmium telluride, zinc telluride, and mercury zinc telluride solar cells
This report describes research to demonstrate (1) thin film cadmium telluride solar cells with a quantum efficiency of 75% or higher at 0. 44 {mu}m and a photovoltaic efficiency of 11.5% or greater, and (2) thin film zinc telluride and mercury zinc telluride solar cells with a transparency to sub-band-gap radiation of 65% and a photovoltaic conversion efficiency of 5% and 8%, respectively. Work was directed at (1) depositing transparent conducting semiconductor films by solution growth and metal-organic chemical vapor deposition (MOCVD) technique, (2) depositing CdTe films by close-spaced sublimation (CSS) and MOCVD techniques, (3) preparing and evaluating thin film CdTe solar cells, and (4) preparing and characterizing thin film ZnTe, CD{sub 1-x}Zn{sub 1-x}Te, and Hg{sub 1-x}Zn{sub x}Te solar cells. The deposition of CdS films from aqueous solutions was investigated in detail, and their crystallographic, optical, and electrical properties were characterized. CdTe films were deposited from DMCd and DIPTe at 400{degrees}C using TEGa and AsH{sub 3} as dopants. CdTe films deposited by CSS had significantly better microstructures than those deposited by MOCVD. Deep energy states in CdTe films deposited by CSS and MOCVD were investigated. Thin films of ZnTe, Cd{sub 1- x}Zn{sub x}Te, and Hg{sub 1-x}Zn{sub x}Te were deposited by MOCVD, and their crystallographic, optical, and electrical properties were characterized. 67 refs.
Chu, T.L. (University of South Florida, Tampa, FL (United States))
Real time intelligent process control system for thin film solar cell manufacturing
This project addresses the problem of lower solar conversion efficiency and waste in the typical solar cell manufacturing process. The work from the proposed development will lead toward developing a system which should be able to increase solar panel conversion efficiency by an additional 12-15% resulting in lower cost panels, increased solar technology adoption, reduced carbon emissions and reduced dependency on foreign oil. All solar cell manufacturing processes today suffer from manufacturing inefficiencies that currently lead to lower product quality and lower conversion efficiency, increased product cost and greater material and energy consumption. This results in slower solar energy adoption and extends the time solar cells will reach grid parity with traditional energy sources. The thin film solar panel manufacturers struggle on a daily basis with the problem of thin film thickness non-uniformity and other parameters variances over the deposited substrates, which significantly degrade their manufacturing yield and quality. Optical monitoring of the thin films during the process of the film deposition is widely perceived as a necessary step towards resolving the non-uniformity and non-homogeneity problem. In order to enable the development of an optical control system for solar cell manufacturing, a new type of low cost optical sensor is needed, able to acquire local information about the panel under deposition and measure its local characteristics, including the light scattering in very close proximity to the surface of the film. This information cannot be obtained by monitoring from outside the deposition chamber (as traditional monitoring systems do) due to the significant signal attenuation and loss of its scattering component before the reflected beam reaches the detector. In addition, it would be too costly to install traditional external in-situ monitoring systems to perform any real-time monitoring over large solar panels, since it would require significant equipment refurbishing needed for installation of multiple separate ellipsometric systems, and development of customized software to control all of them simultaneously. The proposed optical monitoring system comprises AccuStrata�s fiber optics sensors installed inside the thin film deposition equipment, a hardware module of different components (beyond the scope of this project) and our software program with iterative predicting capability able to control material bandgap and surface roughness as films are deposited. Our miniature fiber optics monitoring sensors are installed inside the vacuum chamber compartments in very close proximity where the independent layers are deposited (an option patented by us in 2003). The optical monitoring system measures two of the most important parameters of the photovoltaic thin films during deposition on a moving solar panel - material bandgap and surface roughness. In this program each sensor array consists of two fiber optics sensors monitoring two independent areas of the panel under deposition. Based on the monitored parameters and their change in time and from position to position on the panel, the system is able to provide to the equipment operator immediate information about the thin films as they are deposited. This DoE Supply Chain program is considered the first step towards the development of intelligent optical control system capable of dynamically adjusting the manufacturing process �on-the-fly� in order to achieve better performance. The proposed system will improve the thin film solar cell manufacturing by improving the quality of the individual solar cells and will allow for the manufacturing of more consistent and uniform products resulting in higher solar conversion efficiency and manufacturing yield. It will have a significant impact on the multibillion-dollar thin film solar market. We estimate that the financial impact of these improvements if adopted by only 10% of the industry ($7.7 Billion) would result in about $1.5 Billion in savings by 2015 (at the assumed 20% improvement). This can b
George Atanasoff
Thin Film Solar Cells with Light Trapping Transparent Conducting Oxide Layer
Thin film solar cells, if film thickness is thinner than the optical absorption length, typically give lower cell performance. For the thinner structure, electric current loss due to light penetration can offset the electric current gain obtained from higher built-in electric field. Light trapping schemes can increase the effective optical absorption length and thus enhance the electric current for thinner solar cells. Here a new light trapping scheme based on light trapping transparent conducting oxide layer (LT-TCO) is proposed to enhance the performance of thin film solar cells. Three different configurations of integrating the LT-TCO layer in solar cells are proposed and evaluated. This research aims to develop the LT-TCO layer with surface texture and good conductivity by pulsed laser deposition (PLD) technique at low temperature. The LT-TCO layer is fabricated by PLD deposition of Al-doped ZnO to achieve multilayer films by tuning of oxygen pressure. The light trapping effect is examined by optical transmittance measurement and the surface texture is characterized by transmission electron microscopy (TEM) technique. The conductivity of LT-TCO layer is measured by resistivity measurement. Thin film CdTe/CdS solar cells are fabricated by PLD technique to develop baseline solar cells for integration of LT-TCO layer. The as-deposited thin film solar cells show relatively low performance and are further processed with various post-deposition treatments to seek efficiency enhancement. The effects of different processes on cell performance are examined by electrical, optical, and microstructure studies. Air annealing of CdS layer and CdCl2 treatment of CdTe layer combined are found to yield the best cell performance. The fabrication issues that limit the cell performance are discussed and future optimizations in fabrication processes are suggested.
Lu, Tianlin
Thin-Film Solar Cell Fabricated on a Flexible Metallic Substrate
A thin-film solar cell (10) is provided. The thin-film solar cell (10) comprises a flexible metallic substrate (12) having a first surface and a second surface. A back metal contact layer (16) is deposited on the first surface of the flexible metallic substrate (12). A semiconductor absorber layer (14) is deposited on the back metal contact. A photoactive film deposited on the semiconductor absorber layer (14) forms a heterojunction structure and a grid contact (24) deposited on the heterjunction structure. The flexible metal substrate (12) can be constructed of either aluminium or stainless steel. Furthermore, a method of constructing a solar cell is provided. The method comprises providing an aluminum substrate (12), depositing a semiconductor absorber layer (14) on the aluminum substrate (12), and insulating the aluminum substrate (12) from the semiconductor absorber layer (14) to inhibit reaction between the aluminum substrate (12) and the semiconductor absorber layer (14).
Tuttle, J. R.; Noufi, R.; Hasoon, F. S.
All solar cell manufacturing processes today suffer from manufacturing inefficiencies that currently lead to lower product quality and lower conversion efficiency, increased product cost and greater material and energy consumption. This results in slower solar energy adoption and extends the time solar cells will reach grid parity with traditional energy sources. The thin film solar panel manufacturers struggle on a daily basis with the problem of thin film thickness non-uniformity and other parameters variances over the deposited substrates, which significantly degrade their manufacturing yield and quality. Optical monitoring of the thin films during the process of the film deposition is widely perceived as a necessary step towards resolving the non-uniformity and non-homogeneity problem. In order to enable the development of an optical control system for solar cell manufacturing, a new type of low cost optical sensor is needed, able to acquire local information about the panel under deposition and measure its local characteristics, including the light scattering in very close proximity to the surface of the film. This information cannot be obtained by monitoring from outside the deposition chamber (as traditional monitoring systems do) due to the significant signal attenuation and loss of its scattering component before the reflected beam reaches the detector. In addition, it would be too costly to install traditional external in-situ monitoring systems to perform any real-time monitoring over large solar panels, since it would require significant equipment refurbishing needed for installation of multiple separate ellipsometric systems, and development of customized software to control all of them simultaneously. The proposed optical monitoring system comprises AccuStrata�s fiber optics sensors installed inside the thin film deposition equipment, a hardware module of different components (beyond the scope of this project) and our software program with iterative predicting capability able to control material bandgap and surface roughness as films are deposited. Our miniature fiber optics monitoring sensors are installed inside the vacuum chamber compartments in very close proximity where the independent layers are deposited (an option patented by us in 2003). The optical monitoring system measures two of the most important parameters of the photovoltaic thin films during deposition on a moving solar panel - material bandgap and surface roughness. In this program each sensor array consists of two fiber optics sensors monitoring two independent areas of the panel under deposition. Based on the monitored parameters and their change in time and from position to position on the panel, the system is able to provide to the equipment operator immediate information about the thin films as they are deposited. This DoE Supply Chain program is considered the first step towards the development of intelligent optical control system capable of dynamically adjusting the manufacturing process �on-the-fly� in order to achieve better performance. The proposed system will improve the thin film solar cell manufacturing by improving the quality of the individual solar cells and will allow for the manufacturing of more consistent and uniform products resulting in higher solar conversion efficiency and manufacturing yield. It will have a significant impact on the multibillion-dollar thin film solar market. We estimate that the financial impact of these improvements if adopted by only 10% of the industry ($7.7 Billion) would result in about $1.5 Billion in savings by 2015 (at the assumed 20% improvement). This can b
Characterization of the Electronic and Chemical Structure at the Thin Film Solar Cell Interfaces: June 2005 -- June 2009
Study using photoelectron spectroscopy, inverse photoemission, and X-ray absorption and emission to derive the electronic structure of interfaces in CIGSS and CdTe thin-film solar cells.
Heske, C.
Low-cost, deterministic quasi-periodic photonic structures for light trapping in thin film silicon solar cells
Light trapping has been an important issue for thin film silicon solar cells because of the low absorption coefficient in the near infrared range. In this paper, we present a photonic structure which combines anodic aluminum ...
Optimization of processing and modeling issues for thin film solar cell devices: Final report, February 3, 1997--September 1, 1998
This final report describes results achieved under a 20-month NREL subcontract to develop and understand thin-film solar cell technology associated to CuInSe{sub 2} and related alloys, a-Si and its alloys, and CdTe. Modules based on all these thin films are promising candidates to meet DOE's long-range efficiency, reliability and manufacturing cost goals. The critical issues being addressed under this program are intended to provide the science and engineering basis for the development of viable commercial processes and to improve module performance. The generic research issues addressed are: (1) quantitative analysis of processing steps to provide information for efficient commercial-scale equipment design and operation; (2) device characterization relating the device performance to materials properties and process conditions; (3) development of alloy materials with different bandgaps to allow improved device structures for stability and compatibility with module design; (4) development and improved window/heterojunction layers and contacts to improve device performance and reliability; and (5) evaluation of cell stability with respect to device structure and module encapsulation.
Birkmire, R. W.; Phillips, J. E.; Shafarman, W. N.; Hegedus, S. S.; McCandless, B. E.
Properties of High Efficiency CIGS Thin Film Solar Cells
We present experimental results in three areas. Solar cells with an efficiency of 19% have been fabricated with an absorber bandgap in the range of 1.1-1.2 eV. Properties of solar cells fabricated with and without an undoped ZnO layer were compared. The data show that high efficiency cells can be fabricated without using the high-resistivity or undoped ZnO layer. Properties of CIGS solar cells were fabricated from thin absorbers (1 {micro}m) deposited by the three-stage process and simultaneous co-deposition of all the elements. In both cases, solar cells with efficiencies of 16%-17% are obtained.
Ramanathan, K.; Keane, J.; Noufi, R.
Amorphous silicon/polycrystalline thin film solar cells
An improved photovoltaic solar cell is described including a p-type amorphous silicon layer, intrinsic amorphous silicon, and an n-type polycrystalline semiconductor such as cadmium sulfide, cadmium zinc sulfide, zinc selenide, gallium phosphide, and gallium nitride. The polycrystalline semiconductor has an energy bandgap greater than that of the amorphous silicon. The solar cell can be provided as a single-junction device or a multijunction device.
Ullal, H.S.
Design, construction and testing of a high-vacuum anneal chamber for in-situ crystallisation of silicon thin-film solar cells.
??Thin-film solar cells on glass substrates are likely to have a bright future due to the potentially low costs and the short energy payback times.� (more)
Weber, J�rgen Wolfgang
Non-Uniformities in Thin-Film Cadmium Telluride Solar Cells Using Electroluminescence and Photoluminescence: Preprint
It is the purpose of this research to develop specific imaging techniques that have the potential to be fast, in-line tools for quality control in thin-film CdTe solar cells. Electroluminescence (EL) and photoluminescence (PL) are two techniques that are currently under investigation on CdTe small area devices made at Colorado State University. It is our hope to significantly advance the understanding of EL and PL measurements as applied to CdTe. Qualitative analysis of defects and non-uniformities is underway on CdTe using EL, PL, and other imaging techniques.
Zaunbrecher, K.; Johnston, S.; Yan, F.; Sites, J.
Development of Thin Film Silicon Solar Cell Using Inkjet Printed Silicon and Other Inkjet Processes: Cooperative Research and Development Final Report, CRADA Number CRD-07-260
The cost of silicon photovoltaics (Si-PV) can be greatly lowered by developing thin-film crystalline Si solar cells on glass or an equally lower cost substrate. Typically, Si film is deposited by thermal evaporation, plasma enhanced chemical vapor deposition, and sputtering. NREL and Silexos have worked under a CRADA to develop technology to make very low cost solar cells using liquid organic precursors. Typically, cyclopentasilane (CPS) is deposited on a glass substrate and then converted into an a-Si film by UV polymerization followed by low-temperature optical process that crystallizes the amorphous layer. This technique promises to be a very low cost approach for making a Si film.
Sopori, B.
Institute of Photo Electronic Thin Film Devices and Technology...
Place Tianjin Municipality, China Zip 300071 Sector Solar Product A thin-film solar cell research institute in China. References Institute of Photo-Electronic Thin Film Devices...
Thin film polycrystalline silicon solar cells. Second technical progress report, July 16, 1980-October 15, 1980
The objectives of this contract are to fabricate large area thin film silicon solar cells with AM1 efficiency of 10% or greater with good reproducibility and good yield and to assess the feasibility of implementing this process for manufacturing solar cells at a cost of $300/kWe. Efforts have been directed to the purification of metallurgical silicon, the preparation and characterization of substrates and epitaxial silicon layers, and the fabrication and characterization of solar cells. The partial purification of metallurgical silicon by extraction with aqua regia has been further investigated in detail, and the resulting silicon was analyzed by the atomic absorption technique. The unidirectional solidification of aqua regia-extracted metallurgical silicon on graphite was used for the preparation of substrates, and the impurity distribution in the substrate was determined and compared with the impurity content in metallurgical silicon. The effects of heat treatment on the impurity distribution in the substrate and in the epitaxial layer have also been investigated. Large area (30 to 60 cm/sup 2/) solar cells have been prepared from aqua regia-extracted metallurgical silicon substrates by depositing a p-n junction structure using the thermal reduction of trichlorosilane containing appropriate dopants. The AM1 efficiencies are about 9% for cells of 30 to 35 cm/sup 2/ area. Larger area, 60 cm/sup 2/, thin film solar cells have been fabricated for the first time, and their AM1 efficiencies are slightly higher than 8%. The spectral response, minority carrier diffusion length, and I/sub sc/-V/sub oc/ relation in a number of solr cells have been measured.
Advanced processing technology for high-efficiency, thin-film CuInSe{sub 2} and CdTe solar cells. Annual subcontract report, 1 March 1993--28 February 1994
This annual report details activities in research on advanced processing technology for high-effiency, thin-film solar cells.
Morel, D.L.; Ferekides, C.S. [University of South Florida, Tampa, FL (United States)
CIGS Thin-Film Solar Cell Research at NREL: FY04 Results and Accomplishments
Office of Scientific and Technical Information (OSTI)
National Renewable Energy Laboratory National Renewable Energy Laboratory Innovation for Our Energy Future A national laboratory of the U.S. Department of Energy Office of Energy Efficiency & Renewable Energy NREL is operated by Midwest Research Institute ● Battelle Contract No. DE-AC36-99-GO10337 Conference Paper NREL/CP-520-37020 January 2005 CIGS Thin-Film Solar Cell Research at NREL: FY04 Results and Accomplishments K. Ramanathan, R.N. Bhattacharya, M.A. Contreras, F.S. Hasoon, J. Abushama, and R. Noufi Presented at the 2004 DOE Solar Energy Technologies Program Review Meeting October 25-28, 2004 Denver, Colorado NOTICE The submitted manuscript has been offered by an employee of the Midwest Research Institute (MRI), a contractor of the US Government under Contract No. DE-AC36-99GO10337. Accordingly, the US
Copper and Transparent-Conductor Reflectarray Elements on Thin-Film Solar Cell Panels
This work addresses the integration of reflectarray antennas (RA) on thin film Solar Cell (SC) panels, as a mean to save real estate, weight, or cost in platforms such as satellites or transportable autonomous antenna systems. Our goal is to design a good RA unit cell in terms of phase response and bandwidth, while simultaneously achieving high optical transparency and low microwave loss, to preserve good SC and RA energy efficiencies, respectively. Since there is a trade-off between the optical transparency and microwave surface conductivity of a conductor, here both standard copper and transparent conductors are considered. The results obtained at the unit cell level demonstrates the feasibility of integrating RA on a thin-film SC, preserving for the first time good performance in terms of both SC and RA efficiency. For instance, measurement at X-band demonstrate families of cells providing a phase range larger than 270{\\deg} with average microwave loss of -2.45dB (resp. -0.25dB) and average optical transpa...
Dreyer, Philippe; Nicolay, Sylvain; Ballif, Christophe; Perruisseau-Carrier, Julien
Thin Film Solar Cells Derived from Sintered Semiconductor Quantum Dots: Cooperative Research and Development Final Report, CRADA number CRD-07-00226
The NREL/Evident team will develop techniques to fabricate thin film solar cells where the absorption layers comprising the solar cells are derived from sintered semiconductor quantum dots.
Ginley, D. S.
High-Efficiency CdTe and CIGS Thin-Film Solar Cells: Highlights and Challenges
Thin-film photovoltaic (PV) modules of CdTe and Cu(In,Ga)Se{sub 2} (CIGS) have the potential to reach cost-effective PV-generated electricity. These technologies have transitioned from the laboratory to the market place. Pilot production and first-time manufacturing are ramping up to higher capacity and enjoying a flood of venture-capital funding. CIGS solar cells and modules have achieved 19.5% and 13% efficiencies, respectively. Likewise, CdTe cells and modules have reached 16.5% and 10.2% efficiencies, respectively. Even higher efficiencies from the laboratory and from the manufacturing line are only a matter of time. Manufacturing-line yield continues to improve and is surpassing 85%. Long-term stability has been demonstrated for both technologies; however, some failures in the field have also been observed, emphasizing the critical need for understanding degradation mechanisms and packaging options. These two thin-film technologies have a common device/module structure: substrate, base electrode, absorber, junction layer, top electrode, patterning steps for monolithic integration, and encapsulation. The monolithic integration of thin-film solar cells can lead to significant manufacturing cost reduction compared to crystalline Si technology. The CdTe and CIGS modules share common structural elements. In principle, this commonality should lead to similar manufacturing cost per unit area, and thus, the module efficiency becomes the discriminating factor that determines the cost per watt. The long-term potential of the two technologies require R&D emphasis on science and engineering-based challenges to find solutions to achieve targeted cost-effective module performance, and in-field durability. Some of the challenges are common to both, e.g., in-situ process control and diagnostics, thinner absorber, understanding degradation mechanisms, protection from water vapor, and innovation in high-speed processing and module design. Other topics are specific to the technology, such as lower-cost and fast-deposition processes for CIGS, and improved back contact and voltage for CdTe devices.
Noufi, R.; Zweibel, K.
Amorphous thin films for solar-cell applications. Final report, September 11, 1978-September 10, 1979
In Section II, Theoretical Modeling, theories for the capture of electrons by deep centers in hydrogenated amorphous silicon (a-Si:H) and for field-dependent quantum efficiency in a-Si:H are presented. In Section III, Deposition and Doping Studies, the optimization of phosphorus-doped a-Si:H carried out in four different discharge systems is described. Some details of the dc proximity and rf magnetron discharge systems are also provided. Preliminary mass spectroscopy studies of the rf magnetron discharge in both SiH/sub 4/ and SiF/sub 4/ are presented. In Section IV, Experimental Methods for Characterizing a-Si:H, recent work involving photoluminescence of fluorine-doped a-Si:H, photoconductivity spectra, the photoelectromagnetic effect, the photo-Hall effect and tunneling into a-Si:H is presented. Also, studies of the growth mechanism of Pt adsorbed on both crystalline Si and a-Si:H are described. Measurements of the surface photovoltage have been used to estimate the distribution of surface states of phosphorus-doped and undoped a-Si:H. Section V, Formation of Solar-Cell Structures, contains information on stacked or multiple-junction a-Si:H solar cells. In Section VI, Theoretical and Experimental Evaluation of Solar-Cell Parameters, an upper limit of approx. = 400 A is established for the hole diffusion length in undoped a-Si:H. A detailed description of carrier generation, recombination and transport in a-Si:H solar cells is given. Finally, some characteristics of Pd-Schottky-barrier cells are described for different processing histories.
Carlson, D E; Balberg, I; Crandall, R S; Goldstein, B C; Hanak, J J; Pankove, J I; Staebler, D L; Weakliem, H A; Williams, R
CdS/CdTe Thin-Film Solar Cell with a Zinc Stannate Buffer Layer
This paper describes an improved CdS/CdTe polycrystalline thin-film solar-cell device structure that integrates a zinc stannate (Zn2SnO4 or ZTO) buffer layer between the transparent conductive oxide (TCO) layer and the CdS window layer. Zinc stannate films have a high bandgap, high transmittance, low absorptance, and low surface roughness. In addition, these films are chemically stable and exhibit higher resistivities that are roughly matched to that of the CdS window layer in the device structure. Preliminary device results have demonstrated that by integrating a ZTO buffer layer in both SnO2-based and Cd2SnO4 (CTO)-based CdS/CdTe devices, performance and reproducibility can be significantly enhanced
Wu, X.; Sheldon, P.; Mahathongdy, Y.; Ribelin, R.; Mason, A.; Moutinho, H. R.; Coutts, T. J.
Dark Current Transients in Thin-Film CdTe Solar Cells: Preprint
This conference paper describes the Dark current transients measured by changing the voltage bias in a stepwise fashion on CdTe cells results in minutes-long transients after each step. Transients measured at room temperature are controlled by carrier trapping that corresponds to the well known voltage transient phenomena[1]. Transients measured on the same CdTe cell at elevated temperature (60C and 90C) show a much slower decay process. We associate this physical process with''shunt'' current paths induced with reverse bias and removed with forward bias. A different back contact process may produce an opposite voltage dependence. The lack of these transients may be required for the fabrication of ''stable'' thin-film CdTe solar cells.
McMahon, T. J.
Research on polycrystalline thin-film CuGaInSe[sub 2] solar cells
This report describes research to fabricate high-efficiency CdZnS/CuInGaSe[sub 2] (CIGS) thin-film solar cells, and to develop improved transparent conductor window layers such as ZnO. A specific technical milestone was the demonstration of an air mass (AM) 1.5 global, 13% efficient, 1-cm[sup 2]-total-area CIGS thin-film solar cell. Our activities focused on three areas. First, a CIGS deposition: system was modified to double its substrate capacity, thus increasing throughput, which is critical to speeding the process development by providing multiple substrates from the same CIGS run. Second, new tooling was developed to enable an investigation of a modified aqueous CdZnS process. The goal was to improve the yield of this critical step in the device fabrication process. Third, our ZnO sputtering system was upgraded to improve its reliability, and the sputtering parameters were further optimized to improve its properties as a transparent conducting oxide. The characterization of the new CIGS deposition system substrate fixturing was completed, and we produced good thermal uniformity and adequately high temperatures for device-quality CIGS deposition. Both the CIGS and ZnO deposition processes were refined to yield a ZnO//Cd[sub 0.82]Zn[sub 0.18]S/CuIn[sub 0.80]Ga[sub 0.20]Se[sub 2] cell that was verified at NREL under standard testing conditions at 13.1% efficiency with V[sub oc] = 0.581 V, J[sub sc] = 34.8 mA/cm[sup 2], FF = 0.728, and a cell area of 0.979 cm[sup 2].
Stanbery, B.J.; Chen, W.S.; Devaney, W.E.; Stewart, J.W. (Boeing Co., Seattle, WA (United States). Defense and Space Systems Group)
CIGSS Thin Film Solar Cells: Final Subcontract Report, 10 October 2001-30 June 2005
This report describes the I-III-VI2 compounds that are developing into a promising material to meet the energy requirement of the world. CuInSe2 (CIS) and its alloy with Ga and S have shown long-term stability and highest conversion efficiency of 19.5%. Among the various ways of preparing CuIn1-xGaxSe2-ySy (CIGSS)/CdS thin-film solar cells, co-evaporation and sputtering techniques are the most promising. Sputtering is an established process for very high-throughput manufacturing. ARCO Solar, now Shell Solar, pioneered the work in CIS using the sputtering technique. The two-stage process developed by ARCO Solar involved sputtering of a copper and indium layer on molybdenum-coated glass as the first step. In the second step, the copper-indium layers were exposed to a selenium-bearing gas such as hydrogen selenide (H2Se) mixed with argon. The hydrogen selenide breaks down and leaves selenium, which reacts and mixes with the copper and indium in such a way to produce very high-quality CIS absorber layer. Sputtering technology has the added advantage of being easily scaled up and promotes roll-to-roll production on flexible substrates. Preliminary experiments were carried out. ZnO/ZnO:Al deposition by RF magnetron sputtering and CdS deposition by chemical-bath deposition are being carried out on a routine basis.
Dhere, N. G.
Indium phosphide/cadmium sulfide thin-film solar cells. Semiannual report, July 1980-December 1980
InP thin films were deposited by planar reactive deposition on recyrstallized CdS (RXCdS) and semi-insulating (100) InP substrates and evaluated as potential layers for an all-thin-film solar cell. Films prepared on RXCdS at approximately 330/sup 0/C contained a mixture of grains having both large and submicron lateral dimensions. SIMS analysis showed the interdiffusion profiles to be well behaved and, within the resolution of the analysis, no significant difference in the profiles between structures prepared at 330/sup 0/C and 380/sup 0/C. Be-doped epitaxial films, deposited on semi-insulating InP at 330/sup 0/C, showed both n- and p-type behavior. Films prepared at higher and lower temperatures with a freshly Be-charged In source were p-type and n-type, respectively; the n-type behavior is associated with an excess of n-type native defects. SIMS analyses confirmed the presence of Be in all Be-doped films. Growth with deviation from stoichiometry was initiated at 330/sup 0/C to reduce the concentration of native defects. Growth of Be-doped films at higher substrate temperature with the same Be-doped source after several runs eventually resulted in n-type films. Analyses of the In source and films were initiated to determine the cause of the transient doping. As an alternative to Be doping, p-type Zn-doped InP films were prepared on InP semi-insulating substrates with room-temperature carrier concentration and mobilities of 6 x 10/sup 16/ cm/sup -3/, and 80 cm/sup 2//Vsec, respectively.
Zanio, K.
Functional requirements for component films in a solar thin-film photovoltaic/thermal panel
The functional requirements of the component films of a solar thin-film photovoltaic/thermal panel were considered. Particular emphasis was placed on the new functions, that each layer is required to perform, in addition to their pre-existing functions. The cut-off wavelength of the window layer, required for solar selectivity, can be achieved with charge carrier concentrations typical of photovoltaic devices, and thus does not compromise electrical efficiency. The upper (semiconductor) absorber layer has a sufficiently high thermal conductivity that there is negligible temperature difference across the film, and thus negligible loss in thermal performance. The lower (cermet) absorber layer can be fabricated with a high ceramic content, to maintain high solar selectivity, without significant increase in electrical resistance. A thin layer of molybdenum-based cermet at the top of this layer can provide an Ohmic contact to the upper absorber layer. A layer of aluminium nitride between the metal substrate and the back metal contact can provide electrical isolation to avoid short-circuiting of series-connected cells, while maintaining a thermal path to the metal substrate and heat extraction systems. Potential problems of differential contraction of heated films and substrates were identified, with a recommendation that fabrication processes, which avoid heating, are preferable. (author)
Johnston, David [Power and Energy Research Group, School of Engineering, Northumbria University, Ellison Place, Newcastle upon Tyne NE1 8ST (United Kingdom)
Thin Film Photovoltaics - Programmaster.org
Thin Film Structures for Energy Efficient Systems: Thin Film Photovoltaics ... Full- inorganic Heterojunction Ink-printed Solar Cells: Seigo Ito1; 1University of Hyogo ... electrochemical impedance spectroscopy (EIS) measurements were used for�...
22nd European Photovoltaic Solar Energy Conference, Milan, 3-7 September 2007 Cu(InGa)Se2 THIN-FILM SOLAR CELLS
22nd European Photovoltaic Solar Energy Conference, Milan, 3-7 September 2007 Cu(InGa)Se2 THIN-FILM SOLAR CELLS: COMPARATIVE LIFE-CYCLE ANALYSIS OF BUFFER LAYERS Vasilis M. Fthenakis and Hyung Chul Kim National Photovoltaic EH&S Research Center Brookhaven National Laboratory Upton, NY 11973, USA ABSTRACT
Optimization of Processing and Modeling Issues for Thin-Film Solar Cell Devices; Annual Report, 3 February 1997-2 February 1998
This report describes results achieved during phase I of a four-phase subcontract to develop and understand thin-film solar cell technology associated with CuInSe2 and related alloys, a-Si and its alloys, and CdTe. Modules based on all these thin films are promising candidates to meet DOE long-range efficiency, reliability, and manufacturing cost goals. The critical issues being addressed under this program are intended to provide the science and engineering basis for developing viable commercial processes and to improve module performance. The generic research issues addressed are: (1) quantitative analysis of processing steps to provide information for efficient commercial-scale equipment design and operation; (2) device characterization relating the device performance to materials properties and process conditions; (3) development of alloy materials with different bandgaps to allow improved device structures for stability and compatibility with module design; (4) development of improved window/heterojunction layers and contacts to improve device performance and reliability; and (5) evaluation of cell stability with respect to illumination, temperature, and ambient and with respect to device structure and module encapsulation.
Birkmire, R. W.; Phillips, J. E.; Shafarman, W. N.; Hegedus, S. S.; McCandless, B. E. (IEC, University of Delaware)
Optimization of Processing and Modeling Issues for Thin Film Solar Cell Devices: Final Report, 24 August 1998-23 October 2001
This report describes results achieved during a three-year subcontract to develop and understand thin-film solar cell technology associated to CuInSe2 and related alloys, a-Si and its alloys, and CdTe. Modules based on all these thin films are promising candidates to meet DOE long-range efficiency, reliability, and manufacturing cost goals. The critical issues being addressed under this program are intended to provide the science and engineering basis for the development of viable commercial processes and to improve module performance. The generic research issues addressed are: (1) quantitative analysis of processing steps to provide information for efficient commercial-scale equipment design and operation; (2) device characterization relating the device performance to materials properties and process conditions; (3) development of alloy materials with different bandgaps to allow improved device structures for stability and compatibility with module design; (4) development of improved window/heterojunction layers and contacts to improve device performance and reliability; and (5) evaluation of cell stability with respect to illumination, temperature, and ambient and with respect to device structure and module encapsulation.
Birkmire, R. W.; Phillips, J. E.; Shafarman, W. N.; Eser, E.; Hegedus, S. S.; McCandless, B. E.; Aparicio, R.; Dobson, K.
Cu(In,Ga)Se2 Thin-Film Concentrator Solar Cells: Preprint
Presented at the 2001 NCPV Program Review Meeting: CIGS cells were designed for operation under concentrated sunlight. This is first report of polycrystalline thin-film cell with efficiency>20%.
Ward, J.; Ramanathan, K.; Hasoon, F.; Coutts, T.; Keane, J.; Moriarty, T; Noufi, R.
Methods for forming thin-film heterojunction solar cells from I-III-VI[sub 2
An improved thin-film, large area solar cell, and methods for forming the same are disclosed, having a relatively high light-to-electrical energy conversion efficiency and characterized in that the cell comprises a p-n type heterojunction formed of: (1) a first semiconductor layer comprising a photovoltaic active material selected from the class of I-III-VI[sub 2] chalcopyrite ternary materials which is vacuum deposited in a thin composition-graded'' layer ranging from on the order of about 2.5 microns to about 5.0 microns ([approx equal]2.5[mu]m to [approx equal]5.0[mu]m) and wherein the lower region of the photovoltaic active material preferably comprises a low resistivity region of p-type semiconductor material having a superimposed region of relatively high resistivity, transient n-type semiconductor material defining a transient p-n homojunction; and (2), a second semiconductor layer comprising a low resistivity n-type semiconductor material; wherein interdiffusion (a) between the elemental constituents of the two discrete juxtaposed regions of the first semiconductor layer defining a transient p-n homojunction layer, and (b) between the transient n-type material in the first semiconductor layer and the second n-type semiconductor layer, is allowed.
Mickelsen, R.A.; Chen, W.S.
Methods for forming thin-film heterojunction solar cells from I-III-VI{sub 2}
An improved thin-film, large area solar cell, and methods for forming the same are disclosed, having a relatively high light-to-electrical energy conversion efficiency and characterized in that the cell comprises a p-n type heterojunction formed of: (i) a first semiconductor layer comprising a photovoltaic active material selected from the class of I-III-VI{sub 2} chalcopyrite ternary materials which is vacuum deposited in a thin ``composition-graded`` layer ranging from on the order of about 2.5 microns to about 5.0 microns ({approx_equal}2.5 {mu}m to {approx_equal}5.0 {mu}m) and wherein the lower region of the photovoltaic active material preferably comprises a low resistivity region of p-type semiconductor material having a superimposed region of relatively high resistivity, transient n-type semiconductor material defining a transient p-n homojunction; and (ii) a second semiconductor layer comprising a low resistivity n-type semiconductor material; wherein interdiffusion occurs (a) between the elemental constituents of the two discrete juxtaposed regions of the first semiconductor layer defining a transient p-n homojunction layer, and (b) between the transient n-type material in the first semiconductor layer and the second n-type semiconductor layer. 16 figs.
Methods for forming thin-film heterojunction solar cells from I-III-VI.sub. 2
An improved thin-film, large area solar cell, and methods for forming the same, having a relatively high light-to-electrical energy conversion efficiency and characterized in that the cell comprises a p-n type heterojunction formed of: (i) a first semiconductor layer comprising a photovoltaic active material selected from the class of I-III-VI.sub.2 chalcopyrite ternary materials which is vacuum deposited in a thin "composition-graded" layer ranging from on the order ot about 2.5 microns to about 5.0 microns (.congruent.2.5 .mu.m to .congruent.5.0 .mu.m) and wherein the lower region of the photovoltaic active material preferably comprises a low resistivity region of p-type semiconductor material having a superimposed region of relatively high resistivity, transient n-type semiconductor material defining a transient p-n homojunction; and (ii), a second semiconductor layer comprising a low resistivity n-type semiconductor material; wherein interdiffusion (a) between the elemental constituents of the two discrete juxtaposed regions of the first semiconductor layer defining a transient p-n homojunction layer, and (b) between the transient n-type material in the first semiconductor layer and the second n-type semiconductor layer, causes the The Government has rights in this invention pursuant to Contract No. EG-77-C-01-4042, Subcontract No. XJ-9-8021-1 awarded by the U.S. Department of Energy.
Mickelsen, Reid A. (Bellevue, WA); Chen, Wen S. (Seattle, WA)
An improved thin-film, large area solar cell, and methods for forming the same, having a relatively high light-to-electrical energy conversion efficiency and characterized in that the cell comprises a p-n type heterojunction formed of: (i) a first semiconductor layer comprising a photovoltaic active material selected from the class of I-III-VI.sub.2 chalcopyrite ternary materials which is vacuum deposited in a thin "composition-graded" layer ranging from on the order of about 2.5 microns to about 5.0 microns (.congruent.2.5.mu.m to .congruent.5.0.mu.m) and wherein the lower region of the photovoltaic active material preferably comprises a low resistivity region of p-type semiconductor material having a superimposed region of relatively high resistivity, transient n-type semiconductor material defining a transient p-n homojunction; and (ii), a second semiconductor layer comprising a low resistivity n-type semiconductor material; wherein interdiffusion (a) between the elemental constituents of the two discrete juxtaposed regions of the first semiconductor layer defining a transient p-n homojunction layer, and (b) between the transient n-type material in the first semiconductor layer and the second n-type semiconductor layer, causes the transient n-type material in The Government has rights in this invention pursuant to Contract No. EG-77-C-01-4042, Subcontract No. XJ-9-8021-1 awarded by the U.S. Department of Energy.
Damp-Heat Induced Degradation of Transparent Conducting Oxides for Thin-Film Solar Cells: Preprint
The stability of intrinsic and Al-doped single- and bi-layer ZnO for thin-film CuInGaSe2 solar cells, along with Al-doped Zn1-xMgxO alloy and Sn-doped In2O3 (ITO) and F-doped SnO2, was evaluated by direct exposure to damp heat (DH) at 85oC and 85% relative humidity. The results show that the DH-induced degradation rates followed the order of Al-doped ZnO and Zn1-xMgxO >> ITO > F:SnO2. The degradation rates of Al:ZnO were slower for films of higher thickness, higher substrate temperature in sputter-deposition, and with dry-out intervals. As inferred from the optical micro-imaging showing the initiation and propagation of degrading patterns and regions, the degradation behavior appears similar for all TCOs, despite the obvious difference in the degradation rate. A degradation mechanism is proposed to explain the temporal process involving thermal hydrolysis.
Pern, F. J.; Noufi, R.; Li, X.; DeHart, C.; To, B.
Development of Commercial Technology for Thin Film Silicon Solar Cells on Glass: Cooperative Research and Development Final Report, CRADA Number CRD-07-209
NREL has conducted basic research relating to high efficiency, low cost, thin film silicon solar cell design and the method of making solar cells. Two patents have been issued to NREL in the above field. In addition, specific process and metrology tools have been developed by NREL. Applied Optical Sciences Corp. (AOS) has expertise in the manufacture of solar cells and has developed its own unique concentrator technology. AOS wants to complement its solar cell expertise and its concentrator technology by manufacturing flat panel thin film silicon solar cell panels. AOS wants to take NREL's research to the next level, using it to develop commercially viable flat pane, thin film silicon solar cell panels. Such a development in equipment, process, and metrology will likely produce the lowest cost solar cell technology for both commercial and residential use. NREL's fundamental research capability and AOS's technology and industrial background are complementary to achieve this product development.
Novel R2R Manufacturable Photonic-Enhanced Thin Film Solar Cells; January 28, 2010 -- January 31, 2011
Final subcontract report for PV Incubator project 'Novel R2R Manufacturable Photonic-Enhanced Thin Film Solar Cells.' The goal of this program was to produce tandem Si cells using photonic bandgap enhancement technology developed at ISU and Lightwave Power that would have an NREL-verified efficiency of 7.5% on 0.25 cm{sup 2} area tandem junction cell on plastic substrates. This goal was met and exceeded within the timeframe and budget of the program. On smaller area cells, the efficiency was even higher, {approx}9.5% (not verified by NREL). Appropriate polymers were developed to fabricate photonic and plasmonic devices on stainless steel, Kapton and PEN substrates. A novel photonic-plasmon structure was developed which shows a promise of improving light absorption in thin film cells, a better light absorption than by any other scheme.
Slafer, D.; Dalal, V.
Studies of pure and nitrogen-incorporated hydrogenated amorphous carbon thin films and their possible application for amorphous silicon solar cells
Hydrogenated amorphous carbon (a-C:H) and nitrogen-incorporated a-C:H (a-C:N:H) thin films were deposited using radio frequency-plasma-enhanced chemical vapor deposition technique and studied for their electrical, optical, and nano-mechanical properties. Introduction of nitrogen and increase of self bias enhanced the conductivity of a-C:H and a-C:N:H films, whereas current-voltage measurement reveals heterojunction formation due to their rectifying behavior. The bandgap of these films was changed over wide range from 1.9 eV to 3.45 eV by varying self bias and the nitrogen incorporation. Further, activation energy was correlated with the electronic structure of a-C:H and a-C:N:H films, and conductivity was discussed as a function of bandgap. Moreover, a-C:N:H films exhibited high hardness and elastic modulus, with maximum values as 42 GPa and 430 GPa, respectively, at -100 V. Observed fascinating electrical, optical, and nano-mechanical properties made it a material of great utility in the development of optoelectronic devices, such as solar cells. In addition, we also performed simulation study for an a-Si:H solar cell, considering a-C:H and C:N:H as window layers, and compared their performance with the a-Si:H solar cell having a-SiC:H as window layer. We also proposed several structures for the development of a near full-spectrum solar cell. Moreover, due to high hardness, a-C:N:H films can be used as a protective and encapsulate layer on solar cells, especially in n-i-p configuration on metal substrate. Nevertheless, a-C:H and a-C:N:H as a window layer can avoid the use of additional hard and protective coating and, hence, minimize the cost of the product.
Dwivedi, Neeraj [Physics of Energy Harvesting Division, National Physical Laboratory (CSIR), K.S. Krishnan Road, New Delhi 110012 (India); Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016 (India); Kumar, Sushil [Physics of Energy Harvesting Division, National Physical Laboratory (CSIR), K.S. Krishnan Road, New Delhi 110012 (India); Malik, Hitendra K. [Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016 (India)
Thin Film CIGS and CdTe Photovoltaic Technologies: Commercialization, Critical Issues, and Applications; Preprint
We report here on the major commercialization aspects of thin-film photovoltaic (PV) technologies based on CIGS and CdTe (a-Si and thin-Si are also reported for completeness on the status of thin-film PV). Worldwide silicon (Si) based PV technologies continues to dominate at more than 94% of the market share, with the share of thin-film PV at less than 6%. However, the market share for thin-film PV in the United States continues to grow rapidly over the past several years and in CY 2006, they had a substantial contribution of about 44%, compared to less than 10% in CY 2003. In CY 2007, thin-film PV market share is expected to surpass that of Si technology in the United States. Worldwide estimated projections for CY 2010 are that thin-film PV production capacity will be more than 3700 MW. A 40-MW thin-film CdTe solar field is currently being installed in Saxony, Germany, and will be completed in early CY 2009. The total project cost is Euro 130 million, which equates to an installed PV system price of Euro 3.25/-watt averaged over the entire solar project. This is the lowest price for any installed PV system in the world today. Critical research, development, and technology issues for thin-film CIGS and CdTe are also elucidated in this paper.
Ullal, H. S.; von Roedern, B.
Research on high-efficiency, single-junction, monolithic, thin-film amorphous silicon solar cells
This document describes the progress made in obtaining stable, a-Si-based submodules that have a large area and high efficiency. Conversion efficiencies of up to 11.95% were obtained in small-area, single-junction a-Si solar cells using textured TiO{sub 2}, superlattice p-layers, graded carbon concentrations near the p/i interface, and highly reflective ITO/silver back contacts. Single- junction a-SiC and a-SiGe p-i-n cells were also fabricated that had conversion efficiencies of 9%--11%, and some recently fabricated stacked-junction cells had conversion efficiencies of about 10%. In materials research boron-doped microcrystalline SiC films were recently developed containing up to 6 at. % carbon with conductivities of 3 {times} 10{sup {minus}3}/{Omega}-cm at room temperature and activation energies of 0.11 eV. Microcrystalline film growth was shown to be strongly influenced by the nature of the substrate, with nucleation occurring more readily on a-Si substrates than on TiO{sub 2}. Stability studies show that light-induced degradation is usually enhanced by the presence of carbon grading near the p/i interface. In general, adding either germanium (from GeH{sub 4}) or carbon (from CH{sub 4}) to the i-layer of a p-i-n cell leads to enhanced light-induced degradation. 13 refs., 80 figs., 17 tabs.
Catalano, A.W.; Carlson, D.E.; Ayra, R.R.; Bennett, M.S.; D'Aiello, R.V.; Dickson, C.R.; Fortmann, C.M.; Goldstein, B.; McVeigh, J.; Morris, J.; Newton, J.L.; Wiedeman, S. (Solarex Corp., Newtown, PA (USA). Thin Film Div.)
Research on high-efficiency, single-junction, monolithic, thin-film amorphous silicon solar cells: Phase II annual subcontract report, 1 January 1985--31 January 1986
This report presents results of the second phase of research on high-efficiency, single-junction, monolithic, thin-film a-Si solar cells. Five glow-discharge deposition systems, including a new in-line, multichamber system, were used to grow both doped and undoped a-Si:H. A large number of silane and disilane gas cylinders were analyzed with a gas chromatography/mass spectroscopy system. Strong correlations were found between the breakdown voltage, the deposition rate, the diffusion length, and the conversion efficiency for varying cathode-anode separations in a DC glow-discharge deposition mode. Tin oxide films were grown by chemical vapor deposition with either tetramethyl tin (TMT) or tin tetrachloride (TTC). The best were grown with TMT, but TTC films had a more controlled texture for light trapping and provided a better contact to the p-layer. The best results were obtained with 7059 glass substrates. Efficiencies as high as 10.86% were obtained in p-i-n cells with superlattice p-layers and as high as 10.74% in cells with both superlattice p- and n-layers. Measurements showed that the boron-doping level in the p-layer can strongly affect transport in the i-layer, which can be minimized by reactive flushing before i-layer deposition. Stability of a-Si:H cells is improved by light doping. 51 refs., 64 figs., 21 tabs.
Carlson, D.E.; Ayra, R.R.; Bennett, M.S.; Catalano, A.; D'Aiello, R.V.; Dickson, C.R.; McVeigh, J.; Newton, J.; O'Dowd, J.; Oswald, R.S.; Rajan, K.
Thin-film polycrystalline silicon solar cells. Quarterly report no. 3, October 16, 1980-January 15, 1981
The objectives of the project are: 1) to develop cell fabrication procedures to further define the maximum capabilities of the conducting oxide/silicon heterojunction solar cells; 2) to optimize the spray fabrication technique for making reproducible high efficiency cells; 3) to assess the stability and the projected lifetime of the cell structure; 4) to identify through appropriate measurements the effects of grain boundaries and intragrain defects on the electronic transport mechanisms in thin-film polycrystalline silicon; and 5) to determine the feasibility of a large-scale fabrication process. Progress is reported.
Final project report - CRADA with United Solar Technologies and Pacific Northwest Laboratory (PNL-021): Thin film materials for low-cost high performance solar concentrators
The objectives of this project were as follows: To develop and evaluate promising low-cost dielectric and polymer-protected thin-film reflective metal coatings to be applied to preformed continuously-curved solar reflector panels to enhance their solar reflectance, and to demonstrate protected solar reflective coatings on preformed solar concentrator panels. The opportunity for this project arose from a search by United Solar Technologies (UST) for organizations and facilities capable of applying reflective coatings to large preformed panels. PNL was identified as being uniquely qualified to participate in this collaborative project.
Martin, P.M.; Affinito, J.D.; Gross, M.E.; Bennett, W.D.
Thin Film Structures for Energy Efficient Systems
Thin film based energy generation and storage devices - Small scale ... Dye- sensitized Solar Cells with Anodized Aluminum Alloy-based Counter-electrodes.
SunShot Initiative: Thin Film Photovoltaics Research
Thin Film Photovoltaics Research Thin Film Photovoltaics Research to someone by E-mail Share SunShot Initiative: Thin Film Photovoltaics Research on Facebook Tweet about SunShot Initiative: Thin Film Photovoltaics Research on Twitter Bookmark SunShot Initiative: Thin Film Photovoltaics Research on Google Bookmark SunShot Initiative: Thin Film Photovoltaics Research on Delicious Rank SunShot Initiative: Thin Film Photovoltaics Research on Digg Find More places to share SunShot Initiative: Thin Film Photovoltaics Research on AddThis.com... Concentrating Solar Power Photovoltaics Research & Development Crystalline Silicon Thin Films Multijunctions Organic Photovoltaics Dye-Sensitized Solar Cells Competitive Awards Systems Integration Balance of Systems Thin Film Photovoltaics Research The U.S. Department of Energy (DOE) supports research and development of
Preparation of thin film solar cells under very low pressure conditions. Final report, October 1, 1976--September 30, 1977
In this study the feasibility of fabricating backwall Schottky barrier polycrystalline solar cells under ultra-high vacuum conditions of 1 x 10/sup -10/ torr (N/sub 2/) was investigated. Thin films of electron beam vaporized silicon were deposited on cleaned metal substrates of tungsten, tantalum and hafnium. Mass spectra from the quadrapole residual gas analyzer were used to determine the partial pressure of peak heights of 13 residual gases during each processing step. During separate silicon depositions, the substrate temperature was varied between 400 and 750/sup 0/C and deposition rates between 20 and 750 A/min were used. Surface contamination and metal diffusion were monitored by in situ Auger electron spectrometry before and after cleaning, deposition and annealing. Auger depth profiling, x-ray analysis, and SEM in the topographic and channeling modes, were utilized to characterize the samples with respect to silicon-metal boundary layer, interdiffusion, silicide formation and grain size of silicon. The clean metal surface was found to enhance thin film silicide growth. Fine grain silicon films were obtained for all samples that were not completely converted to a metallic silicide. Tungsten, tantalum and hafnium were found to form silicides at temperatures as low as 600/sup 0/C.
Schmidt, F.A.; Shanks, H.R.; Bevolo, A.J.; Campisi, G.J.
Physical models of thin film polycrystalline solar cells based on measured grain-boundary and electronic-parameter properties. Final report, September 18, 1978-December 31, 1979
The research has sought the following: to identify and characterize the basic photovoltaic mechanisms that govern the conversion efficiency of polycrystalline thin-film solar cells; to experimentally determine the electronic parameters related to these photovoltaic mechanisms; and to relate these mechanisms and parameters to the conversion efficiency through theoretical physical models developed for engineering design. These objectives are all intimately related. The emphasis of the work has been on polysilicon, although it is building a foundation of understanding useful for similar research in the future on other thin-film materials. Progress is reported. (WHK)
Lindholm, F.A.; Fossum, J.G.; Holloway, P.A.; Neugroschel, A.
Ultrasonically Sprayed and Inkjet Printed Thin Film Electrodes for Organic Solar Cells
Thin film pi-conjugated poly(3,4ethylenedioxythiophene): poly(styrenesulphonate) (PEDOT:PSS) as a hole transport layer on indium tin oxide is a key element in some of the most efficient organic photovoltaic and light emitting devices to date. Films are typically deposited by spincoating, which is not readily scalable. In this paper we investigate the critical parameters for both inkjet and ultrasonic spray deposition of PEDOT:PSS thin films on commercial indium tin oxide as a potentially scalable approach to contact formation. Inkjet parameters investigated include drop spacing and substrate temperature. Ultrasonic spray coating parameters investigated include substrate temperature and solution flow rate. We also show that the ink viscosity has a Newtonian character, making it well suited for inkjet printing. Films were characterized via optical profilometry, sheet resistance and atomic force microscopy. Optimized inkjet printed and ultrasonic sprayed PEDOT:PSS films were then compared to spincast layers in a prototypical bulk heterojunction photovoltaic device employing a poly(3-hexylthiophene) and [6,6]-PCBM (6,6-phenylC61-butyric acid-methyl ester) blend as the absorber. Practically all three approaches produced devices of comparable efficiency. Efficiencies were 3.6%, 3.5% and 3.3% for spin, spray and inkjet depositions respectively.
Steirer, K. X.; Berry, J. J.; Reese, M. O.; van Hest, M. F. A. M.; Miedaner, A.; Liberatore, M. W.; Collins, R. T.; Ginley, D. S.
21-kW Thin-Film PV Technology Validation -- An NREL/Solar Energy Centre of India MOU Cooperative Project
This paper summarizes findings during a one-week (27-31 October 2003) site visit to the Thin-Film Technology Test Bed at India's Solar Energy Centre (SEC) near New Delhi. The U.S. and Indian governments signed a Memorandum of Understanding in March 2000 to undertake a 50-50 cost-shared 21-kW thin-film PV technology validation project to evaluate the performance of thin-film photovoltaic (PV) modules under Indian climatic conditions. This project benefits Indian researchers by giving them experience with cost-effective PV materials, and it benefits the United States because data will be sent to the appropriate U.S. thin-film PV manufacturers for evaluation and analysis. During the visit, NREL personnel engaged in technical discussions regarding thin-film PV technologies with Ministry of Non-Conventional Energy Sources engineers and scientists. Issues included inspecting the newly constructed arrays, discussing better methods of electrically loading the PV arrays, taking I-V traces, and gathering baseline I-V data.
McNutt, P. F.; Ullal, H. S.
Applications of Passive Thin Films
The physical properties of thin films affect the performance and durability of nearly every solar energy conversion device. Familiar examples of thin films for solar applications are optical materials and protective coatings. Optimized optical properties are key to cost-effective photothermal conversion where individual components must have high absorptance, reflectance, or transmittance. The protection of sensitive substrates from corrosion and/or erosion is essential to ensure adequate component and system lifetime. Such substrates range from photovoltaic materials operating near room temperature to turbine blade structural alloys in hostile environments at very high temperatures (>1,000 degrees C). Although much has been written on particular categories of thin-film materials for solar energy (for example, absorbers for receiver surfaces), to date no one has provided an overview of the spectrum of applications for passive thin films in solar energy. This work is such an overview and also reviews the material state of the art as described in the current literature. Active thin film devices such as photovoltaics and thermoeleetrics are not discussed.
Call, P. J.
Nanostructured Inorganic Thin Film Enabled Fiber Optic Sensors for ...
... Thin Film Enabled Fiber Optic Sensors for Gas Sensing in Energy and Environmental Systems ... Co-Doped TiO2 Nanoparticles and Thin Films for Enhanced Solar Energy Utilization ... Synthesis of Magnetic Core-TS-1 Zeolite Shell Catalyst.
Thin film cadmium telluride, zinc telluride, and mercury zinc telluride solar cells. Final subcontract report, 1 July 1988--31 December 1991
Chu, T.L. [University of South Florida, Tampa, FL (United States)
methods. The poly-Si solar cell structure and the performance have been examined. In principle, the new process is potentially applicable to produce large-area thin-film poly-Si solar cells at a high throughput and low cost. A critical issue in this process is to prevent the excessive dopant diffusion during crystallization. Process parameters and the cell structure have to be optimized to achieve the production goal.
Yue Kuo
Thin films of mixed metal compounds
A compositionally uniform thin film of a mixed metal compound is formed by simultaneously evaporating a first metal compound and a second metal compound from independent sources. The mean free path between the vapor particles is reduced by a gas and the mixed vapors are deposited uniformly. The invention finds particular utility in forming thin film heterojunction solar cells.
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. 5 figs.
Catalano, A.W.; Bhushan, M.
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)
Tianjin Jinneng Solar Cell Co Ltd | Open Energy Information
Municipality, China Zip 300384 Sector Solar Product Chinese manufacturer of a-si Tandem thin-film solar cells and PV system integrator. References Tianjin Jinneng Solar Cell Co...
Boron arsenide thin film solar cell development. Quarterly report No. 1
A large portion of the effort expended in the first quarter was devoted to the design, assembly, and testing of the film growth apparatus. The reactor has been completed and tested by depositing boron from diborane gas onto heated quartz substrates. The objective of this effort was to achieve film growth, which has been accomplished. Within the last month, attempts to grow boron arsenide films have been made by introducing both diborane and arsine into the reactor. Thin films have been grown on quartz and sapphire (alumina) substrates. Variations in film thickness, composition, degree of crystallinity, and conductivity have been observed as a result of variation of the deposition parameters, such as type and flow rate of carrier gases, substrate temperature, and substrate materials. X-ray analysis of several samples indicates that films containing boron and arsenic have been grown. No crystalline films have been produced to date. Electrical and optical measurements indicate some correlation between at least one of the films grown and the results achieved by Chu, et al. on BAs. Thus far, the electrical conductivity, film topography, optical absorption, index of refraction, impurity type, and photo-conductivity have been investigated on one sample. This material appears to be B/sub x/As/sub y/ and could be BAs. Further investigations will be required to be conclusive.
Boone, J.L.; Van Doren, T.P.
Wide-Gap Thin Film Si n-i-p Solar Cells Deposited by Hot-Wire CVD: Preprint
High-voltage wide bandgap thin-film Si n-i-p solar cells have been made using the hot-wire chemical vapor deposition (HWCVD) technique. The best open-circuit voltage (Voc) has exceeded 0.94 V in solar cells using HWCVD in the entire n-i-p structure. A Voc of 0.97V has been achieved using HWCVD in the n and i layers and plasma-enhanced (PE) CVD for the p layer. The high voltages are attributed to the wide-gap i layer and an improved p/i interface. The wide-gap i layer is obtained by using low substrate temperatures and sufficient hydrogen dilution during the growth of the i layer to arrive at the amorphous-to-microcrystalline phase transition region. The optical band gap (E04) of the i layer is found to be 1.90 eV. These high-voltage cells also exhibit good fill factors exceeding 0.7 with short-circuit-current densities of 8 to 10 mA/cm2 on bare stainless steel substrates. We have also carried out photoluminescence (PL) spectroscopy studies and found a correlation between Voc and the PL peak energy position.
Wang, Q.; Iwaniczko, E.; Yang, J.; Lord, K.; Guha, S.; Wang, K.; Han, D.
Development of high-efficiency, thin-film CdTe solar cells. Annual subcontract report, January 1, 1993--December 31, 1993
Polycrystalline thin film CdTe solar cells are one of the leading candidates for terrestrial photovoltaic applications. Theoretical calculations project an efficiency of 27% for single crystal, single junction CdTe cells, and the practically achievable efficiency for polycrystalline CdTe cells is 18-20%. Polycrystalline CdTe cells made by different groups show a significant variation in short circuit currents, open circuit voltages, and cell efficiencies. A better understanding of carrier loss and transport mechanism is crucial for explaining these differences, improving the yield, and bridging the gap between current and practically achievable limits in CdTe cell efficiencies. The goal of this program is to improve the understanding of the loss mechanisms in thin film CdS/CdTe solar cells and to improve their efficiency by characterizing the properties of the films as well as the finished devices.
Rohatgi, A.; Chou, H.C.; Kamra, S.; Bhat, A. [Georgia Institute of Technology, Atlanta, GA (United States)
Survey of Development of CZTS-based Thin Film Solar Cells
About this Abstract. Meeting, 2013 TMS Annual Meeting & Exhibition. Symposium , Alloys and Compounds for Thermoelectric and Solar Cell Applications.
Optimization of Processing and Modeling Issues for Thin Film Solar Cell Devices Including Concepts for the Development of Polycrystalline Multijunctions Annual Subcontract Report, 24 August 1999 - 23 August 2000
This report describes the results achieved during Phase I of a three-phase subcontract to develop and understand thin-film solar cell technology associated with CuInSe2 and related alloys, a-Si and its alloys, and CdTe. Modules based on all these thin films are promising candidates to meet DOE long-range efficiency, reliability, and manufacturing cost goals. The critical issues being addressed under this program are intended to provide the science and engineering basis for developing viable commercial processes and to improve module performance. The generic research issues addressed are: (1) quantitative analysis of processing steps to provide information for efficient commercial-scale equipment design and operation; (2) device characterization relating the device performance to materials properties and process conditions; (3) development of alloy materials with different bandgaps to allow improved device structures for stability and compatibility with module design; (4) development of improved window/heterojunction layers and contacts to improve device performance and reliability; and (5) evaluation of cell stability with respect to illumination, temperature, and ambient, and with respect to device structure and module encapsulation.
Birkmire, R. W.; Phillips, J. E.; Shafarman, W. N.; Eser, E.; Hegedus, S. S.; McCandless, B. E.
A novel thin-film poly-Si fabrication process has been demonstrated. This low thermal budget process transforms the single- and multi-layer amorphous silicon thin films into a poly-Si structure in one simple step over a pulsed rapid thermal annealing process with the enhancement of an ultrathin Ni layer. The complete poly-Si solar cell was fabricated in a short period of time without deteriorating the underneath glass substrate. The unique vertical crystallization process including the mechanism is discussed. Influences of the dopant type and process parameters on crystal structure will be revealed. The poly-Si film structure has been proved using TEM, XRD, Raman, and XPS methods. The poly-Si solar cell structure and the performance have been examined. In principle, the new process is potentially applicable to produce large-area thin-film poly-Si solar cells at a high throughput and low cost. A critical issue in this process is to prevent the excessive dopant diffusion during crystallization. Process parameters and the cell structure have to be optimized to achieve the production goal.
Properties of double-layered Ga-doped Al-zinc-oxide/titanium-doped indium-tin-oxide thin films prepared by dc magnetron sputtering applied for Si-based thin film solar cells
In this article, Ga-doped Al-zinc-oxide (GAZO)/titanium-doped indium-tin-oxide (ITIO) bi-layer films were deposited onto glass substrates by direct current (dc) magnetron sputtering. The bottom ITIO film, with a thickness of 200 nm, was sputtered onto the glass substrate. The ITIO film was post-annealed at 350 deg. C for 10-120 min as a seed layer. The effect of post-annealing conditions on the morphologies, electrical, and optical properties of ITIO films was investigated. A GAZO layer with a thickness of 1200 nm was continuously sputtered onto the ITIO bottom layer. The results show that the properties of the GAZO/ITIO films were strongly dependent on the post-annealed conditions. The spectral haze (T{sub diffuse}/T{sub total}) of the GAZO/ITIO bi-layer films increases upon increasing the post-annealing time. The haze and resistivity of the GAZO/ITIO bi-layer films were improved with the post-annealed process. After optimizing the deposition and annealing parameters, the GAZO/ITIO bi-layer film has an average transmittance of 83.20% at the 400-800 nm wavelengths, a maximum haze of 16%, and the lowest resistivity of 1.04 x 10{sup -3}{Omega} cm. Finally, the GAZO/ITIO bi-layer films, as a front electrode for silicon-based thin film solar cells, obtained a maximum efficiency of 7.10%. These encouraging experimental results have potential applications in GAZO/ITIO bi-layer film deposition by in-line sputtering without the wet-etching process and enable the production of highly efficient, low-cost thin film solar cells.
Wang, Chao-Chun; Wuu, Dong-Sing; Lin, Yang-Shih; Lien, Shui-Yang; Huang, Yung-Chuan; Liu, Chueh-Yang; Chen, Chia-Fu; Nautiyal, Asheesh; Lee, Shuo-Jen [Department of Materials Science and Engineering, National Chung Hsing University, Taichung 40227, Taiwan (China); Department of Materials Science and Engineering, MingDao University, Changhua 52345, Taiwan (China); Department of Mechanical Engineering, Yuan Ze University, Taoyuan 320, Taiwan (China)
High efficiency thin-film GaAs solar cells. First interim report, March 1--August 30, 1977
The objective is to demonstrate the feasibility of producing high-efficiency (15% or greater) thin-film GaAs solar cells with costs suitable for terrestrial solar electric power generation. The approach is that of growing GaAs by organio-metallic chemical vapor deposition on recrystallized germanium (Ge) films previously deposited on metal substrates and fabricating AMOS (Antireflecting Metal-Oxide-Semiconductor) solar cells on the GaAs. Previously it had been determined that a water vapor-grown native oxide (temperature = 25/sup 0/C) was the most useful native oxide for AMOS cells. A new chemical surface preparation prior to oxide growth led to more uniform oxides and reduced interface contamination, yielding lower reverse saturation current densities, a near-unity diode ideality factor, and better reproducibility. Substituting silver (Ag) for gold metallization showed no change in starting cell efficiency, but did greatly improve high temperature stability of the AMOS solar cell. A new study was completed on antireflection coatings on AMOS GaAs solar cells, taking into account the spectral response of the cell and nature of the solar spectra, and the results submitted for publication. XPS (X-ray Photoelectron Spectroscopy) studies had found earlier that the more efficient native oxides had primarily As/sub 2/O/sub 3/ and Ga/sub 2/O/sub 3/ with little GaAsO/sub 4/. A new chemical step etching was developed which can be used to profile the oxide in 5- to 7-A/sup 0/ steps without modifying the oxide chemistry as does ion sputtering. A new Schottky barrier structure is described which can give cell efficiencies up to 16% without oxide interfacial layer effects and 20 to 22% with a moderate interfacial layer effect. AMOS solar cells fabricated on sliced polycrystalline GaAs wafers with 100- to 500-..mu..m grains using Sb/sub 2/O/sub 3/ deposited oxides showed 14% cell efficiency compared to 16.2% in a region with few grains.
Stirn, R.J.
Light trapping in thin film solar cells using textured photonic crystal
A solar cell includes a photoactive region that receives light. A photonic crystal is coupled to the photoactive region, wherein the photonic crystal comprises a distributed Bragg reflector (DBR) for trapping the light.
Yi, Yasha (Somerville, MA); Kimerling, Lionel C. (Concord, MA); Duan, Xiaoman (Amesbury, MA); Zeng, Lirong (Cambridge, MA)
Barrier Coatings for Thin Film Solar Cells: Final Subcontract Report, September 1, 2002 -- January 30, 2008
This program has involved investigations of the stability of CdTe and copper-indium-gallium-diselenide (CIGS) solar cells under damp heat conditions and effects of barrier coatings.
Olsen, L. C.
NREL Produces Highly Efficient, Wide-Bandgap, Thin-Film Solar...
Low-bandgap cells can lose 25% of their power output and efficiency ratings as solar cell operating temperatures climb to 75C or more, a common occurrence in hot and arid...
High Performance CIGS Thin-Film Solar Cells: A Laboratory Perspective
We present a summary of our work on the preparation of CuInGaSe2 (CIGS) absorbers that has led to fabricating record-efficiency solar cells. The use of the three-stage process in conjunction with composition monitoring facilitates the fabrication of solar cells with efficiencies between 18% and 19.5% for absorber bandgap in the range of 1.1-1.2 eV. We describe our recent results in reducing absorber thickness and low-temperature deposition. Our preliminary results on absorbers grown from low-purity source materials show promise of reducing the cost of fabricating the absorber.
Ramanathan, K.; Bhattacharya, R.; Contreras, M.; Keane, J. C.; To, B.; Dhere, R. G.; Noufi, R.
Surface Treatment of CuInGaSe2 Thin Films and Its Effect on the Photovoltaic Properties of Solar Cells: Preprint
Solar cells have been fabricated with partial electrolyte treatments of CuInGaSe2 (CIGS) thin-film absorbers in lieu of a CdS layer. Treatment of the absorbers in a containing Cd or Zn solution is shown to produce conditions under which efficient solar cells can be fabricated. A similar effect is also observed in CuInGaSSe2 (CIGSS) graded-bandgap absorbers. These observations can be explained by the ability of Cd and Zn to produce n-type doping or inversion in the surface region. We also provide a brief review of similar work done elsewhere and identify directions for future investigations.
Ramanathan, K.; Hasoon, F.S.; Smith, S.; Young, D.L.; Contreras, M.A.; Johnson, P.K.; Pudov, A.O.; Sites, J.R.
Heteroepitaxial Si Thin Films Deposited on Flexible Copper ...
Presentation Title, Heteroepitaxial Si Thin Films Deposited on Flexible Copper Substrates for Solar Photovoltaics. Author(s), Daniela Florentina Bogorin, Lee�...
High-Efficiency CdTe and CIGS Thin-Film Solar Cells: Highlights and Challenges; Preprint
Thin-film photovoltaic (PV) modules of CdTe and Cu(In,Ga)Se2 (CIGS) have the potential to reach cost-effective PV-generated electricity. These technologies have transitioned from the laboratory to the market place. Pilot production and first-time manufacturing are ramping up to higher capacity and enjoying a flood of venture-capital funding. CIGS solar cells and modules have achieved 19.5% and 13% efficiencies, respectively. Likewise, CdTe cells and modules have reached 16.5% and 10.2% efficiencies, respectively. Even higher efficiencies from the laboratory and from the manufacturing line are only a matter of time. Manufacturing-line yield continues to improve and is surpassing 85%. Long-term stability has been demonstrated for both technologies; however, some failures in the field have also been observed, emphasizing the critical need for understanding degradation mechanisms and packaging options. The long-term potential of the two technologies require R&D emphasis on science and engineering-based challenges to find solutions to achieve targeted cost-effective module performance, and in-field durability. Some of the challenges are common to both, e.g., in-situ process control and diagnostics, thinner absorber, understanding degradation mechanisms, protection from water vapor, and innovation in high-speed processing and module design. Other topics are specific to the technology, such as lower-cost and fast-deposition processes for CIGS, and improved back contact and voltage for CdTe devices.
Development of recrystallization and thin-film solar cell processes. Final report, October 1, 1977-September 30, 1978
The program had two thrusts: (1) based upon electron-beam thermal treatment of deposited silicon films, to increase crystallite sizes to the range thought to be useful for polycrystalline, thin-film cell fabrication; and (2) to explore the feasibility of applying the directed-energy technologies of ion implantation and pulsed electron beam activation, previously developed for silicon cell fabrication, to junction formation in III-V compounds. The culmination of the recrystallization effort was demonstrating grains broader than the 30-..mu..m film in which they were regrown. This proof of principle was accomplished by means of two-step thermal process that consisted of large-area pulsed electron beam melting followed by small-area heating in a moving DC electron beam. The pulsed beam treatment reduced the three-dimensional disorder of the initial submicrometer crystallite silicon film to one characterized by submicrometercross-section, full-film-thickness, columnar crystallites. The swept beam treatment allowed coalesence of these columnar crystallites, through directional freezing, in the melt path of the beam. It is believed that this demonstration is the first evidence of greater-than-film thickness recrystallization of useful thickness silicon films other than by extended heat treatment at greater than 1350/sup 0/C. The results of the studies on junction formation in III-V materials, while not so dramatic, have shown that low-energy ion implantation is a potentially viable alternative to liquid or vapor phase epitaxy in the fabrication of GaAs solar cells. Further, the technical feasibility of pulsed electron beam activation of ion implanted junctions in GaAs has been demonstrated. Lastly, the concept of forming front-layer windows of GaP and AlGaAs on GaAs by high-dose ion implantation has been shown to be technically feasible.
Solomon, S.J.
Thin film polycrystalline silicon solar cells. Quarterly report No. 1, January 1, 1979-March 31, 1979
A theory capable of predicting the performance of polycrystalline silicon solar cells is formulated. It relates grain size to mobility, lifetime, diffusion length, reverse saturation current, open circuit photovoltage and fill factor. Only the diffusion lengths measured by the surface photovoltage technique for grains less than or equal to 5 ..mu..m do not agree with our theory. The reason for this discrepancy is presently being investigated. We conclude that grains greater than or equal to 100 ..mu..m are necessary to achieve efficiencies greater than or equal to 10 percent at AM1 irradiance. The calculations were performed for the case of no grain boundary passivation. At present we are investigating the improvements to be expected from grain boundary passivation. We have determined that the parameters that best fit the available data are as follows: (1) Number of surface states at grain boundaries acting as recombination centers - 1.6 x 10/sup 13//cm/sup 2/. (2) Capture cross section - 2 x 10/sup -16/ cm/sup 2/. (3) Surface recombination velocity at grain boundary - 3.2 x 10/sup 4/ cm/sec. The following types of solar cells are considered in the model: SnO/sub 2//Si Heterostructure, MIS, and p/n junction. In all types of solar cells considered, grain boundary recombination plays a dominant role, especially for small grains. Though the calculations were originally expected to yield only order of magnitude results, they have proven to be accurate for most parameters within 10 percent.
Ghosh, A.K.; Feng, T.; Maruska, H.P.; Fishman, C.
Identification and Analysis of Distinct Features in Imaging Thin-Film Solar Cells: Preprint
Electroluminescence and photoluminescence (EL and PL) are two imaging techniques employed at NREL that are used to qualitatively evaluate solar cells. In this work, imaging lab-scale CdTe and CIGS devices provides information about small-area PV response, which will aid in determining the effects of non-uniformities on cell performance. EL, PL, and dark lock-in thermography signatures are first catalogued. Their responses to varying conditions are then studied. Further analysis includes acquiring spectral data, making microscopy measurements, and correlating luminescence to device performance. The goal of this work is to quantitatively determine non-uniformity effects on cell performance using rapid imaging techniques.
Zaunbrecher, K. N.; Johnston, S. W.; Sites, J. R.
Thin film polycrystalline silicon solar cells. Quarterly report No. 1, October 1-December 31, 1979
The MoSi/sub 2/ separation layer growth rate has been studied as a function of time and temperature. The presence of small amounts of O/sub 2/ in the silicon deposition ambient were found to inhibit the growth rate of the MoSi/sub 2/ layer and also to affect the reliability of shear separation. Void formation in silicon at the Si-MoSi/sub 2/ interface, due predominantly to diffusion of silicon through the MoSi/sub 2/ layer was observed. This is believed to be responsible for shear separation occurring in the silicon film. Gas chromatograhic procedures were developed for characterizing the silicon deposition process. Coherent twin bundles in the grain-enhanced silicon films were not found to adversely influence solar cell efficiency. Several 1 cm x 2 cm solar cells were fabricated. Performance characteristics of these cells are discussed; the best device had a conversion efficiency of 10.7% (under simulated AM1 illumination) with V/sub OC/ = 0.545 V, J/sub SC/ = 28.65 mA/cm/sup 2/ and FF = 68.3%.
Sarma, K.R.; Rice, M.J.; Legge, R.
Thin Films Thin Films Manufacturing Technologies The Thin Film laboratory provides a variety of vapor deposition processes and facilities for cooperative research and development. Available capabilities include electron beam evaporation, sputter deposition, reactive deposi- tion processes, atomic layer deposition (ALD) and specialized techniques such as focused ion beam induced chemical vapor deposition. Equipment can be reconfigured for prototyping, or it can be dedicated to long-term research, development and manufacturing. Most sputter and evaporative deposition systems are capable of depositing multiple materials. Deposition capabilities and expertise * Deposition of a large variety of thin film mate- rials * Multiple sputter deposition systems - Capable of depositing four materials in a
Superhydrophobic Thin Film Coatings
Exploiting its expertise with thin films and superhydrophobic materials, ORNL has developed a simple, inexpensive way to apply and reliably bond ...
CARS of Thin Films
... as a thin film diagnostic. Surface enhanced Raman scattering, SERS, has been used to probe the interfacial region of thin polymer films on metal ...
Polycrystalline thin-film cadmium telluride solar cells fabricated by electrodeposition. Annual technical report
During the past year, Colorado School of Mines (CSM) researchers performed systematic studies of the growth and properties of electrodeposition CdS and back-contact formation using Cu-doped ZnTe, with an emphasis on low Cu concentrations. CSM also started to explore the stability of its ZnTe-Cu contacted CdTe solar cells. Researchers investigated the electrodeposition of CdS and its application in fabricating CdTe/CdS solar cells. The experimental conditions they explored in this study were pH from 2.0 to 3.0; temperatures of 80 and 90 C; CdCl{sub 2} concentration of 0.2 M; deposition potential from {minus}550 to {minus}600 mV vs. Ag/AgCl electrode; [Na{sub 2}S{sub 2}O{sub 4}] concentration between 0.005 and 0.05 M. The deposition rate increases with increase of the thiosulfate concentration and decrease of solution pH. Researchers also extended their previous research of ZnTe:Cu films by investigating films doped with low Cu concentrations (< 5 at. %). The low Cu concentration enabled them to increase the ZnTe:Cu post-annealing temperature without causing excessive Cu diffusion into CdTe or formation of secondary phases. The effects of Cu doping concentration and post-deposition annealing temperature on the structural, compositional, and electrical properties of ZnTe were studied systematically using X-ray diffraction, atomic force microscopy, electron microprobe, Hall effect, and conductivity measurements.
Trefny, J.U.; Mao, D. [Colorado School of Mines, Golden, CO (United States). Dept. of Physics
High-efficiency cadmium and zinc-telluride-based thin-film solar cells
This report describes research into polycrystalline CdTe solar cells grown by metal-organic chemical vapor deposition. Efficiencies of {approximately}10% were achieved using both p-i-n and p-n structures. A pre-heat treatment of CdS/SnO{sub 2}/glass substrates at 450{degrees}C in hydrogen atmosphere prior to the CdTe growth was found to be essential for high performance because this heat treatment reduces oxygen-related defects from the CdS surface. However, this treatment also resulted in a Cd-deficient CdS surface, which may in part limit the CdTe cell efficiency to 10% due to Cd vacancy-related interface defects. Preliminary model calculations suggest that removing these states can increase the cell efficiency from 10% to 13.5%. Photon absorption in the CdS film also limits the cell performance, and eliminating this loss mechanism can result in CdTe efficiencies in excess of 18%. Polycrystalline, 1.7-e, CdZnTe films were also grown for tandem-cell applications. CdZnTe/CdS cells processed using the standard CdTe cell fabrication procedure resulted in 4.4% efficiency, high series resistance, and a band-gap shift to 1.55 eV. The formation of Zn-O at and near the CdZnTe surface is the source of high contact resistance. A saturated dichromate each prior to contact deposition was found to solve the contact resistance problem. The CdCl{sub 2} treatment was identified as the cause of the observed band-gap shift due to the preferred formation of ZnCl{sub 2}. 59 refs.
Rohatgi, A.; Sudharsanan, R.; Ringel, S. (Georgia Inst. of Tech., Atlanta, GA (United States))
Development of copper sulfide/cadmium sulfide thin-film solar cells
The purpose of this work has been to identify aspects of cell fabrication and treatment which are critical for achieving high efficiency Cu/sub 2/S/CdS solar cells. In approaching the problem several comparisons were made of the effects of specific steps in two methods of cell fabrication. These methods had previously given cells of about 6% and a maximum of 9% efficiency. Three areas requiring special attention and specific means to achieve acceptable results were identified. (1) The Cu/sub 2/S/CdS heterojunction area must be minimized. If single source evaporations of CdS are made on substrates whose temperatures (approx. 220/sup 0/C) are monitored and controlled using welded thermocouples, the CdS films will have adequately large grains (grain diameter greater than or equal to 2 ..mu..m) and will not develop significant etch pits during texturing in a mild etchant solution. (2) The termination of the wet barrier processing steps must be done carefully. An acceptable termination involves minimizing the amount of cuprous chloride retained on the cell surface during transfer to a rinsing stage while providing adequate exclusion of air from the space above the surface of the cuprous chloride solution. (3) Once formed, the Cu/sub 2/S layer should not be exposed to high temperatures (>100/sup 0/C) for long periods of time (> 5 min) if surface adsorbed moisture or oxygen are present. Heat treatments in ampoules under flowing hydrogen atmospheres should be preceded and followed by periods of at least 30 minutes at room temperature in the reducing ambient. If all these precautions are taken, wet chemical barrier processing of thermally evaporated CdS films on zinc-plated copper foil substrates yields cells of nearly 8% conversion efficiency without AR coating.
Szedon, J.R.; Biter, W.J.; Abel, J.A.; Dickey, H.C.; Shirland, F.A.
Optical modeling of a-Si solar cells
The authors describe applications of PV Optics to analyze the behavior of a metallic back-reflector on an a-Si solar cell. The calculated results from PV Optics agree well with the measured data on solar cells. Several unexpected results obtained from these calculations are qualitatively explained.
Sopori, B.; Madjdpour, J.; Zhang, Y.; Chen, W.; Guha, S.; Yang, J.; Banerjee, A.; Hegedus, S.
Development of a Wide Bandgap Cell for Thin Film Tandem Solar Cells: Final Technical Report, 6 November 2003 - 5 January 2007
The objective of this research program was to develop approaches for a transparent wide-bandgap cell to be used in a thin-film tandem polycrystalline solar cell that can ultimately attain 25% efficiency. Specific goals included the research and development of Cu(InGa)(SeS)2 and Cd1-xZnxTe alloys with a bandgap from 1.5 to 1.8 eV, demonstrating the potential of a 15% cell efficiency with a transparent contact, and supporting the High Performance PV Program. This Final Report presents results that emphasize the 3rd phase of the program.
Shafarman, W.; McCandless, B.
Research on high-efficiency, single-junction, monolithic, thin-film amorphous silicon solar cells: Annual subcontract report, May 1985 - Jul 1986
A study was undertaken of the optoelectronic properties of amorphous silicon-hydrogen thin films deposited from disilane at high deposition rates. The information derived from this study was used to fabricate amorphous silicon solar cells with efficiencies exceeding 7%. The intrinsic layer of these solar cells was deposited at 15 angstroms/second. Material properties investigated included dark conductivity, photoconductivity, minority carrier diffusion length, and density of states. The solar cells properties characterized were absolute quantum yield and simulated global AM 1.5 efficiencies. Investigations were undertaken utilizing optical and infrared spectroscopy to optimize the microstructures of the intrinsic amorphous silicon. That work was sponsored by the New York State Energy Research and Development Authority. The information was used to optimize the intrinsic layer of amorphous silicon solar cells, resulting in AM 1.5 efficiencies exceeding 7%.
Wiesmann, H.; Dolan, J.; Fricano, G.; Danginis, V.
Design Method for Light Absorption Enhancement in Ultra-Thin Film ...
ultra-thin film organic solar cells (OSCs) to improve the light absorption. ... In the promising field of solar cells, organic solar cells (OSCs) are advantageous in its�...
Terra Solar Global Inc | Open Energy Information
(a-Si) thin-film modules, inverters, and various balance of system components such as batteries, converters, and charge controllers for use in PV systems. References Terra Solar...
Theoretical Analysis of Effects of Deep Level, Back Contact, and Absorber Thickness on Capacitance-Voltage Profiling of CdTe Thin-Film Solar Cells
The apparent carrier density profile measured by the capacitance-voltage technique in CdTe thin-film solar cells frequently displays a distinctive U-shape. We show that, even assuming a uniform carrier density, such a U-shape may arise from deep levels, a non-ohmic back-contact, and a thin absorber, which are commonly present in practical CdTe thin-film solar cells. A thin CdTe absorber contributes to the right branch of the U-shape due to a punch-through effect at reverse or zero biases, when the CdTe absorber is nearly fully depleted. A rectifying back-contact contributes to both branches of the U-shape due to voltage sharing with the front junction under a forward bias and early punch-through under a reverse bias. Deep levels contribute to the right branch, but also raise the bottom of the U-shape, leading to an overestimate of carrier density.
Li, J. V.; Halverson, A. F.; Sulima, O. V.; Bansal, S.; Burst, J. M.; Barnes, T. M.; Gessert, T. A.; Levi, D. H.
Thin film hydrogen sensor
A thin film hydrogen sensor, includes: a substantially flat ceramic substrate with first and second planar sides and a first substrate end opposite a second substrate end; a thin film temperature responsive resistor on the first planar side of the substrate proximate to the first substrate end; a thin film hydrogen responsive metal resistor on the first planar side of the substrate proximate to the fist substrate end and proximate to the temperature responsive resistor; and a heater on the second planar side of the substrate proximate to the first end.
Cheng, Yang-Tse (Rochester Hills, MI); Poli, Andrea A. (Livonia, MI); Meltser, Mark Alexander (Pittsford, NY)
Design and fabrication of photonic crystal thin film photovoltaic cells Guillaume Gomarda,b
Design and fabrication of photonic crystal thin film photovoltaic cells Guillaume Gomarda,b , Ounsi of an absorbing planar photonic crystal within a thin film photovoltaic cell. The devices are based on a stack with large areas. Keywords: Photonic crystal, Photovoltaic solar cell, Thin film solar cell, Hydrogenated
Thin film tritium dosimetry
The present invention provides a method for tritium dosimetry. A dosimeter comprising a thin film of a material having relatively sensitive RITAC-RITAP dosimetry properties is exposed to radiation from tritium, and after the dosimeter has been removed from the source of the radiation, the low energy electron dose deposited in the thin film is determined by radiation-induced, thermally-activated polarization dosimetry techniques.
Moran, Paul R. (Madison, WI)
Characterization of Field Exposed Thin Film Modules: Preprint
Test arrays of thin film modules have been deployed at the Solar Energy Centre near New Delhi, India since 2002-2003. Performances of these arrays were reported by O.S. Sastry [1]. This paper reports on NREL efforts to support SEC by performing detailed characterization of selected modules from the array. Modules were selected to demonstrate both average and worst case power loss over the 8 years of outdoor exposure. The modules characterized included CdTe, CIS and three different types of a-Si. All but one of the a-Si types were glass-glass construction. None of the modules had edge seals. Detailed results of these tests are presented along with our conclusions about the causes of the power loss for each technology.
Wohlgemuth, J. H.; Sastry, O. S.; Stokes, A.; Singh, Y. K.; Kumar, M.
Biological, Electronic, and Functional Thin Films and Coatings I
Mar 4, 2013... scan (PPS) and electrical impedance spectroscopy (EIS). ... Eclipse Active and Passive Solar Control Coatings: Hulya ... In this paper two novel thin film coating systems will be presented for energy conservation solar�...
Cadmium-free junction fabrication process for CuInSe.sub.2 thin film solar cells
The present invention provides an economical, simple, dry and controllable semiconductor layer junction forming process to make cadmium free high efficiency photovoltaic cells having a first layer comprised primarily of copper indium diselenide having a thin doped copper indium diselenide n-type region, generated by thermal diffusion with a group II(b) element such as zinc, and a halide, such as chlorine, and a second layer comprised of a conventional zinc oxide bilayer. A photovoltaic device according the present invention includes a first thin film layer of semiconductor material formed primarily from copper indium diselenide. Doping of the copper indium diselenide with zinc chloride is accomplished using either a zinc chloride solution or a solid zinc chloride material. Thermal diffusion of zinc chloride into the copper indium diselenide upper region creates the thin n-type copper indium diselenide surface. A second thin film layer of semiconductor material comprising zinc oxide is then applied in two layers. The first layer comprises a thin layer of high resistivity zinc oxide. The second relatively thick layer of zinc oxide is doped to exhibit low resistivity.
Ramanathan, Kannan V. (Lakewood, CA); Contreras, Miguel A. (Golden, CA); Bhattacharya, Raghu N. (Littleton, CA); Keane, James (Lakewood, CA); Noufi, Rommel (Golden, CA)
Method of fabricating high-efficiency Cu(In,Ga)(Se,S){sub 2} thin films for solar cells
A process for producing a slightly Cu-poor thin film of Cu(In,Ga)(Se,S){sub 2} comprises depositing a first layer of (In,Ga){sub x} (Se,S){sub y} followed by depositing just enough Cu+(Se,S) or Cu{sub x} (Se,S) to produce the desired slightly Cu-poor material. In a variation, most, but not all, (about 90 to 99%) of the (In,Ga){sub x} (Se,S){sub y} is deposited first, followed by deposition of all the Cu+(Se,S) or Cu{sub x} (Se,S) to go near stoichiometric, possibly or even preferably slightly Cu-rich, and then in turn followed by deposition of the remainder (about 1 to 10%) of the (In,Ga){sub x} (Se,S){sub y} to end with a slightly Cu-poor composition. In yet another variation, a small portion (about 1 to 10%) of the (In,Ga){sub x} (Se,S){sub y} is first deposited as a seed layer, followed by deposition of all of the Cu+(Se,S) or Cu{sub x} (Se,S) to make a very Cu-rich mixture, and then followed deposition of the remainder of the (In,Ga){sub x} (Se,S){sub y} to go slightly Cu-poor in the final Cu(In,Ga)(Se,S){sub 2} thin film. 5 figs.
Noufi, R.; Gabor, A.M.; Tuttle, J.R.; Tennant, A.L.; Contreras, M.A.; Albin, D.S.; Carapella, J.J.
Method of fabricating high-efficiency Cu(In,Ga)(SeS).sub.2 thin films for solar cells
A process for producing a slightly Cu-poor thin film of Cu(In,Ga)(Se,S).sub.2 comprises depositing a first layer of (In,Ga).sub.x (Se,S).sub.y followed by depositing just enough Cu+(Se,S) or Cu.sub.x (Se,S) to produce the desired slightly Cu-poor material. In a variation, most, but not all, (about 90 to 99%) of the (In,Ga).sub.x (Se,S).sub.y is deposited first, followed by deposition of all the Cu+(Se,S) or Cu.sub.x (Se,S) to go near stoichiometric, possibly or even preferably slightly Cu-rich, and then in turn followed by deposition of the remainder (about 1 to 10%) of the (In,Ga).sub.x (Se,S).sub.y to end with a slightly Cu-poor composition. In yet another variation, a small portion (about 1 to 10%) of the (In,Ga).sub.x (Se,S).sub.y is first deposited as a seed layer, followed by deposition of all of the Cu+(Se,S) or Cu.sub.x (Se,S) to make a very Cu-rich mixture, and then followed deposition of the remainder of the (In,Ga).sub.x (Se,S).sub.y to go slightly Cu-poor in the final Cu(In,Ga)(Se,S).sub.2 thin film.
Noufi, Rommel (Golden, CO); Gabor, Andrew M. (Boulder, CO); Tuttle, John R. (Denver, CO); Tennant, Andrew L. (Denver, CO); Contreras, Miguel A. (Golden, CO); Albin, David S. (Denver, CO); Carapella, Jeffrey J. (Evergreen, CO)
Research on polycrystalline thin-film CuInGaSe{sub 2} solar cells. Annual subcontract report, 3 May 1991--21 May 1993
This report describes work to fabricate high-efficiency CdZnS/CuInGaSe{sub 2}, thin-film solar cells and to develop improved transparent conductor window layers such as ZnO. The specific technical milestone for Phase I was to demonstrate an air mass (AM) 1.5 global 13% , 1-cm{sup 2} total-area CuInGaSe{sub 2} (CIGS) thin-film solar cell. For Phase II, the objective was to demonstrate an AM1.5 global 13.5%, 1-cm{sup 2} total-area efficiency. We focused our activities on three areas. First, we modified the CIGS deposition system to double its substrate capacity. Second, we developed new tooling to enable investigation of a modified aqueous CdZnS process in which the goal was to improve the yield of this critical step in the device fabrication process. Third, we upgraded the ZnO sputtering system to improve its reliability and reproducibility. A dual rotatable cathode metallic source was installed, and the sputtering parameters were further optimized to improve ZnO`s properties as a transparent conducting oxide (TCO). Combining the refined CdZnS process with CIGS from the newly fixtured deposition system enable us to fabricate and deliver a ZnO/Cd{sub 0.08}Zn{sub 0.20}S/CuIn{sub 0.74}Ga{sub 0.26}Se{sub 2} cell on alumina with I-V characteristics, as measured by NREL under standard test conditions, of 13.7% efficiency with V{proportional_to} = 0.5458 V, J{sub sc} = 35.48 mA/cm{sup 2}, FF = 0.688, and efficiency = 14.6%.
Chen, W.S.; Stewart, J.M.; Mickelsen, R.A.; Devaney, W.E.; Stanbery, B.J. [Boeing Co., Seattle, WA (United States). Defense and Space Systems Group
Research on polycrystalline thin-film CuGaInSe{sub 2} solar cells. Annual subcontract report, 3 May 1991--2 May 1992
This report describes research to fabricate high-efficiency CdZnS/CuInGaSe{sub 2} (CIGS) thin-film solar cells, and to develop improved transparent conductor window layers such as ZnO. A specific technical milestone was the demonstration of an air mass (AM) 1.5 global, 13% efficient, 1-cm{sup 2}-total-area CIGS thin-film solar cell. Our activities focused on three areas. First, a CIGS deposition: system was modified to double its substrate capacity, thus increasing throughput, which is critical to speeding the process development by providing multiple substrates from the same CIGS run. Second, new tooling was developed to enable an investigation of a modified aqueous CdZnS process. The goal was to improve the yield of this critical step in the device fabrication process. Third, our ZnO sputtering system was upgraded to improve its reliability, and the sputtering parameters were further optimized to improve its properties as a transparent conducting oxide. The characterization of the new CIGS deposition system substrate fixturing was completed, and we produced good thermal uniformity and adequately high temperatures for device-quality CIGS deposition. Both the CIGS and ZnO deposition processes were refined to yield a ZnO//Cd{sub 0.82}Zn{sub 0.18}S/CuIn{sub 0.80}Ga{sub 0.20}Se{sub 2} cell that was verified at NREL under standard testing conditions at 13.1% efficiency with V{sub oc} = 0.581 V, J{sub sc} = 34.8 mA/cm{sup 2}, FF = 0.728, and a cell area of 0.979 cm{sup 2}.
Stanbery, B.J.; Chen, W.S.; Devaney, W.E.; Stewart, J.W. [Boeing Co., Seattle, WA (United States). Defense and Space Systems Group
Sputtered Nickel Oxide Thin Film for Efficient Hole Transport Layer in Polymer-Fullerene Bulk-Heterojunction Organic Solar Cell
Bulk-heterojunction (BHJ) organic photovoltaics (OPV) are very promising thin film renewable energy conversion technologies due to low production cost by high-throughput roll-to-roll manufacturing, an expansive list of compatible materials, and flexible device fabrication. An important aspect of OPV device efficiency is good contact engineering. The use of oxide thin films for this application offers increased design flexibility and improved chemical stability. Here we present our investigation of radio frequency magnetron sputtered nickel oxide (NiO{sub x}) deposited from oxide targets as an efficient, easily scalable hole transport layer (HTL) with variable work-function, ranging from 4.8 to 5.8 eV. Differences in HTL work-function were not found to result in statistically significant changes in open circuit voltage (V{sub oc}) for poly(3-hexylthiophene):[6,6]-phenyl-C{sub 61}-butyric acid methyl ester (P3HT:PCBM) BHJ device. Ultraviolet photoemission spectroscopy (UPS) characterization of the NiO{sub x} film and its interface with the polymer shows Fermi level alignment of the polymer with the NiO{sub x} film. UPS of the blend also demonstrates Fermi level alignment of the organic active layer with the HTL, consistent with the lack of correlation between V{sub oc} and HTL work-function. Instead, trends in j{sub sc}, V{sub oc}, and thus overall device performance are related to the surface treatment of the HTL prior to active layer deposition through changes in active layer thickness.
Widjonarko, N. E.; Ratcliff, E. L.; Perkins, C. L.; Sigdel, A. K.; Zakutayev, A.; Ndione, P. F.; Gillaspie, D. T.; Ginley, D. S.; Olson, D. C.; Berry, J. J.
Thin Film Nanocomposites for Thermoelectric Applications
Presentation Title, Thin Film Nanocomposites for Thermoelectric Applications ... Abstract Scope, Thin film nanocomposites comprised of refractory metals and�...
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)
Thin film photovoltaic cell
A thin film photovoltaic cell having a transparent electrical contact and an opaque electrical contact with a pair of semiconductors therebetween includes utilizing one of the electrical contacts as a substrate and wherein the inner surface thereof is modified by microroughening while being macro-planar.
Meakin, John D. (Newark, DE); Bragagnolo, Julio (Newark, DE)
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 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)
2 Thin Films Prepared by Sequential Evaporation for Photovoltaic
The defects of Cu-Se di-vacancies are formed in Cu(In,Ga)Se2 thin films and influence to the solar cell performance. In this study, we have fabricated Cu(In�...
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)
Physical models of thin film polycrystalline solar cells based on measured grain-boundary and electronic-parameter properties. Quarterly report
Solar cells fabricated on polycrystalline silicon, either bulk or thin-film, can potentially be cost-effective when used in terrestrial photovoltaic energy-conversion systems. To achieve this goal, the polysilicon cell efficiency must be increased considerably from its present values. A severe limitation to the cell efficiency is due to the grain boundaries and their influence on carrier recombination. To remove this limitation, an understanding of the fundamental physics underlying the effects of the grain boundaries on cell performance is helpful. This fundamental physics is discussed, and models are developed for recombination currents in polysilicon pn-junction solar cells. Several analytic approximations, suggested by physical insight, are used and checked ultimately for self-consistency with the results of the analysis. The models are defined such that their parameters can be related directly to measurements, and the models are hence useful in interpreting experimental results. They also can be used to study, in a systematic way, cell-design modifications to improve the efficiency, e.g., grain-boundary passivation techniques.
Polycrystalline thin film materials and devices
Results of Phase II of a research program on polycrystalline thin film heterojunction solar cells are presented. Relations between processing, materials properties and device performance were studied. The analysis of these solar cells explains how minority carrier recombination at the interface and at grain boundaries can be reduced by doping of windows and absorber layers, such as in high efficiency CdTe and CuInSe{sub 2} based solar cells. The additional geometric dimension introduced by the polycrystallinity must be taken into consideration. The solar cells are limited by the diode current, caused by recombination in the space charge region. J-V characteristics of CuInSe{sub 2}/(CdZn)S cells were analyzed. Current-voltage and spectral response measurements were also made on high efficiency CdTe/CdS thin film solar cells prepared by vacuum evaporation. Cu-In bilayers were reacted with Se and H{sub 2}Se gas to form CuInSe{sub 2} films; the reaction pathways and the precursor were studied. Several approaches to fabrication of these thin film solar cells in a superstrate configuration were explored. A self-consistent picture of the effects of processing on the evolution of CdTe cells was developed.
Baron, B.N.; Birkmire, R.W.; Phillips, J.E.; Shafarman, W.N.; Hegedus, S.S.; McCandless, B.E. (Delaware Univ., Newark, DE (United States). Inst. of Energy Conversion)
INCREASED CELL EFFICIENCY IN InGaAs THIN FILM SOLAR CELLS WITH DIELECTRIC AND METAL BACK REFLECTORS
solar cells enable very high photovoltaic efficiencies by virtue of employing different band gap to increase the short circuit current and the photovoltaic efficiency of solar cells. INTRODUCTION Multi-junction solar cells based on III-V compound semiconductors are the most efficient photovoltaic devic- es
Heaton, Thomas H.
Institute of Photo Electronic Thin Film Devices and Technology of Nankai
Electronic Thin Film Devices and Technology of Nankai Electronic Thin Film Devices and Technology of Nankai University Jump to: navigation, search Name Institute of Photo-Electronic Thin Film Devices and Technology of Nankai University Place Tianjin Municipality, China Zip 300071 Sector Solar Product A thin-film solar cell research institute in China. References Institute of Photo-Electronic Thin Film Devices and Technology of Nankai University[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. Institute of Photo-Electronic Thin Film Devices and Technology of Nankai University is a company located in Tianjin Municipality, China . References ↑ "Institute of Photo-Electronic Thin Film Devices and Technology of Nankai University"
Indium phosphide/cadmium sulfide thin-film solar cells. Final report, May 1979 through July 1980
Thin-film InP/RXCdS/ITO/GLASS devices were prepared by depositing ITO on low-cost glass substrate, depositing CdS on the ITO by thermal evaporation, increasing the CdS lateral grain size by recrystallization, and depositing p-type InP by planar reactive deposition (PRD) on the recrystallized CdS (RXCdS). Yields of the RXCdS/ITO/GLASS substrates were increased to 90% with lateral dimensions of the RXCdS grains as large as 0.3 mm. P-type InP layers were obtained with Be doping. S-doping via vapor transport from the CdS was eliminated by capping the entire RXCdS substrate with InP. For InP deposited on RXCdS at 380/sup 0/C, devices showed blocking action with a barrier height of about 0.5 V but no light response, possibly due to an intermediate approx. 3-..mu..m-thick n-InP layer from diffusion of S from the RXCdS. These results were achieved despite poor InP epitaxy due to an approx. 0.5-..mu..m-thick In-Cd-S transition layer between the InP and the RXCdS. InP films were subsequently deposited on RXCdS at the reduced substrate temperature of 280/sup 0/C to reduce S-diffusion and improve the quality of the epitaxy. Complete InP epitaxy on RXCdS was achieved with the lateral dimensions of the InP (approx. = 40 ..mu..m) replicating that of the RXCdS. Given the increase in the concentration of n-type native defects as substrate temperature is decreased, the present lower limit for obtaining p-type InP by vacuum technologies appears to be about 300/sup 0/C. A 300 to 350/sup 0/C range of substrate temperature appears to befeasible for preparing large-grained p-type InP for both frontwall and backwall cell. However, if the thickness of the n-type layer due to S diffusion cannot be kept to less than a few thousand Angstroms, then development must be restricted to the frontwall cells.
CdSiAs/sub 2/ thin films for solar cell applications. Final report, April 9, 1979-April 8, 1980
Compounds of Cd-Si-As required for sputtering targets and evaporation charges were synthesized by direct fusion. These include CdSiAs/sub 2/, Cd/sub 3/As/sub 2/, CdAs/sub 2/ and SiAs. Polycrystalline ingots of CdSiAs/sub 2/ were found to be porous, with the chalcopyrite structure, and with minor amounts of other phases such as CdAs/sub 2/, SiAs,As and Cd/sub 3/As/sub 2/. Sputtered films were formed in a single target RF system. A homogeneous CdSiAs/sub 2/ target was initially used, followed by composite targets consisting of CdAs/sub 2/ + Si. Films from the latter targets were superior to the others and were more extensively studied. As deposited films were amorphous, off stoichiometry, with resistivities over 10/sup 8/..cap omega..-cm and band gaps of approx. 1.4 eV. Subsequent reactive heat treatments in the 515/sup 0/ to 615/sup 0/C range resulted in crystalline films, resistivities of 1 to 10 ..cap omega.. cm, CdSiAs/sub 2/ compositions within 1% of stoichiometry, energy gap of approx. 1.55 eV, absorption coefficient of 2 x 10/sup 4/cm/sup -1/ at 0.6 ..mu..m, but with poor mechanical properties (mainly cracking). A Ta/Si0/sub 2/ substrate proved to be the best for these films. Thermal evaporation studies of CdSiAs/sub 2/ established that effusion is preferential toward Cd between 570 and 710/sup 0/C, and toward As in the 710 to 1010/sup 0/C range. All films resulting from CdAs/sub 2/ charges were found to be Cd deficient. For these reasons, over the last 6 months of the program, only sputtered films were studied further. Preliminary CdSiAs/sub 2//CdS junctions were formed on bulk and sputtered CdSiAs/sub 2/. The bulk junctions produced photoresponse up to 0.25V and several ..mu..A. The thin film junctions were rectifying, but generated insignificant photoresponse, apparently due to the poor properties of the CdSiAs/sub 2/ films.
Burton, L.C.; Slack, L.H.
Optimization of Phase-Engineered a-Si:H-Based Multi-Junction Solar Cells: Second Annual Technical Status Report, January 2003--January 2004
This subcontract report entails investigation of engineering improvements in the performance and stability of solar cells in a systematic way. It consists of the following four tasks: Task 1-Materials research and device development; Task 2-Process improvement directed by real-time diagnostics; Task 3-Device loss mechanisms; and Task 4-Characterization strategies for advanced materials. The real-time spectroscopic ellipsometry (RTSE) multichamber is near completion, and trial depositions with a-Si:H will begin shortly. Construction of the new dual beam photoconductivity (DBP) apparatus has been completed, and the new capabilities are being used in studies on a-Si:H thin films. A new apparatus is being constructed for in-depth studies on the mechanisms limiting the performance of a-Si:H solar cells and the two track studies (cells and films) of the Staebler-Wronski Effect. The capabilities include the ability to integrate the cell characteristics including the quantum efficiency, at different temperatures on both p-i-n and n-i-p solar cells.
Wronski, C. R.; Collins, R. W.; Vlahos, V.; Pearce, J. M.; Deng, J.; Albert, M.; Ferreira, G. M.; Chen, C.
Apparatus for forming thin-film heterojunction solar cells employing materials selected from the class of I-III-VI.sub.2 chalcopyrite compounds
Apparatus for forming thin-film, large area solar cells having a relatively high light-to-electrical energy conversion efficiency and characterized in that the cell comprises a p-n-type heterojunction formed of: (i) a first semiconductor layer comprising a photovoltaic active material selected from the class of I-III-VI.sub.2 chalcopyrite ternary materials which is vacuum deposited in a thin "composition-graded" layer ranging from on the order of about 2.5 microns to about 5.0 microns (.congruent.2.5 .mu.m to .congruent.5.0 .mu.m) and wherein the lower region of the photovoltaic active material preferably comprises a low resistivity region of p-type semiconductor material having a superimposed region of relatively high resistivity, transient n-type semiconductor material defining a transient p-n homojunction; and (ii), a second semiconductor layer comprising a low resistivity n-type semiconductor material wherein interdiffusion (a) between the elemental constituents of the two discrete juxtaposed regions of the first semiconductor layer defining a transient p-n homojunction layer, and (b) between the transient n-type material in the first semiconductor layer and the second n-type semiconductor layer, causes the transient n-type material in the first semiconductor layer to evolve into p-type material, thereby defining a thin layer heterojunction device characterized by the absence of voids, vacancies and nodules which tend to reduce the energy conversion efficiency of the system.
Thin Films and Interfaces Committee
The Thin Films and Interfaces Committee is part of the Electronic, Magnetic, and Photonic Materials Division;. Our Mission: Promotes knowledge of the science�...
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); Hoffheins, Barbara S. (Knoxville, TN); Fleming, Pamela H. (Oak Ridge, TN)
Epitaxial Thin Film Silicon Solar Cells Fabricated by Hot Wire Chemical Vapor Deposition Below 750 ..deg..C: Preprint
We report on fabricating film c-Si solar cells on Si wafer templates by hot-wire chemical vapor deposition. These devices, grown at glass-compatible temperatures 500 mV and efficiencies > 5%.
Alberi, K.; Martin, I. T.; Shub, M.; Teplin, C. W.; Iwaniczko, E.; Xu, Y.; duda, A.; Stradin, P.; Johnston, S. W.; Romero, M. J.; Branz, H. M.; Young, D. L.
Annealed CVD molybdenum thin film surface
Molybdenum thin films deposited by pyrolytic decomposition of Mo(CO).sub.6 attain, after anneal in a reducing atmosphere at temperatures greater than 700.degree. C., infrared reflectance values greater than reflectance of supersmooth bulk molybdenum. Black molybdenum films deposited under oxidizing conditions and annealed, when covered with an anti-reflecting coating, approach the ideal solar collector characteristic of visible light absorber and infrared energy reflector.
Carver, Gary E. (Tucson, AZ); Seraphin, Bernhard O. (Tucson, AZ)
Thin film ion conducting coating
Durable thin film ion conducting coatings are formed on a transparent glass substrate by the controlled deposition of the mixed oxides of lithium:tantalum or lithium:niobium. The coatings provide durable ion transport sources for thin film solid state storage batteries and electrochromic energy conservation devices.
Goldner, Ronald B. (Lexington, MA); Haas, Terry (Sudbury, MA); Wong, Kwok-Keung (Watertown, MA); Seward, George (Arlington, MA)
Thin films: Past, present, future
This report describes the characteristics of the thin film photovoltaic modules necessary for an acceptable rate of return for rural areas and underdeveloped countries. The topics of the paper include a development of goals of cost and performance for an acceptable PV system, a review of current technologies for meeting these goals, issues and opportunities in thin film technologies.
Zweibel, K.
We report on fabricating film c-Si solar cells on Si wafer templates by hot-wire chemical vapor deposition. These devices, grown at glass-compatible temperatures < 750..deg..C, demonstrate open-circuit voltages > 500 mV and efficiencies > 5%.
Vertically Aligned Nanocomposite Thin Films
Vertically aligned nanocomposite (VAN) thin films have recently stimulated significant research interest to achieve better material functionality or multifunctionalities. In VAN thin films, both phases grow epitaxially in parallel on given substrates and form a unique nano-checkerboard structure. Multiple strains, including the vertical strain which along the vertical interface and the substrate induced strain which along the film and substrate interface, exist in VAN thin films. The competition of these strains gives a promise to tune the material lattice structure and future more the nanocomposite film physical properties. Those two phases in the VAN thin films are selected based on their growth kinetics, thermodynamic stability and epitaxial growth ability on given substrates. In the present work, we investigated unique epitaxial two-phase VAN (BiFeO3)x:(Sm2O3)1-x and (La0.7Sr0.3MnO3)x:(Mn3O4)1-x thin film systems by pulsed laser deposition. These VAN thin films exhibit a highly ordered vertical columnar structure with good epitaxial quality. The strain of the two phases can be tuned by deposition parameters, e.g. deposition frequency and film composition. Their strain tunability is found to be related directly to the systematic variation of the column widths and domain structures. Their physical properties, such as dielectric loss and ferromagnetisms can be tuned systematically by this variation. The growth morphology, microstructure and material functionalities of VAN thin films can be varied by modifying the phase ratio, substrate orientation or deposition conditions. Systematic study has been done on growing (SrTiO3)0.5:(MgO)0.5 VAN thin films on SrTiO3 and MgO substrates, respectively. The variation of column width demonstrates the substrate induced strain plays another important role in the VAN thin film growth. The VAN thin films also hold promise in achieving porous thin films with ordered nanopores by thermal treatment. We selected (BiFeO3)0.5:(Sm2O3)0.5 VAN thin films as a template and get uniformly distributed bi-layered nanopores. Controllable porosity can be achieved by adjusting the microstructure of VAN (BiFeO3):(Sm2O3) thin films and the annealing parameters. In situ heating experiments within a transmission electron microscope column provide direct observations into the phases transformation, evaporation and structure reconstruction during the annealing. Systematic study in this dissertation demonstrate that the vertically aligned nanocomposite microstructure is a brand new architecture in thin films and an exciting approach that promises tunable material functionalities as well as novel nanostructures.
Bi, Zhenxing
NIST Hydrogen Storage in Thin Films
Hydrogen Storage Optimization in Thin Film Combinatorial Alloys. ... Magnesium Thin Films," International Journal of Hydrogen Energy, doi:10.1016/j ...
Thin Film and Nanostructure Processing Group Homepage
... The Thin Film and Nanostructure Processing Group is one of seven ... Deposition of thin films Electrodeposition of metals and alloys Evaporation of ...
Metals Thin-Films Information at NIST
NIST Home > Metals Thin-Films Information at NIST. Metals Thin-Films Information at NIST. (the links below are a compilation ...
Optical Characterization of Advanced Thin Films
... Recently, thin films of spun-cast poly(2,5-bis(3-alkylthiophen ... been demonstrated to exhibit exceptional hole mobilities in thin film transistors (TFTs ...
Interfaces in Nanostructured Functional Oxide Thin Films
The thin film systems include high temperature superconductors (HTS), thin film solid oxide fuel cells (SOFC), and other functional oxide systems. Detailed�...
Thin film gallium arsenide solar cell research. Third quarterly project report, September 1, 1980-November 30, 1980. [Antireflection coating
The major objective of this contract is to produce gallium arsenide solar cells of 10% conversion efficiency in films of less than 10 micrometers thick which have been deposited by chemical vapor deposition on graphite or tungsten coated graphite substrates. Major efforts during this quarter were directed to: (1) the optimization of the deposition of gallium arsenide films of 10 ..mu..m thickness or less on tungsten/graphic substrates, (2) the investigation of the effectiveness of various grain boundary passivation techniques, (3) the deposition of tantalum pentoxide by ion beam sputtering as an antireflection coating, (4) the deposition of gallium aluminium arsenide by the organometallic process, and (5) the fabrication and characterization of large area Schottky barrier type solar cells from gallium arsenide films of about 10 ..mu..m thickness. Various grain boundary passivation techniques, such as the anodic oxidation, thermal oxidation, and ruthenium treatment, have been investigated. The combination of thermal oxidation and ruthenium treatment has been used to fabricate Schottky barrier type solar cells. Large area MOS solar cells of 9 cm/sup 2/ area with AMl efficiency of 8.5% have been fabricated from ruthenium treated gallium arsenide films of 10 ..mu..m thickness. The construction of the apparatus for the deposition of gallium aluminum arsenide by the organometallic process has been completed. The deposition of good quality tantalum pentoxide film as an antireflection coating has been carried out by the ion beam sputtering technique. The short-circuit current density and AMl efficiency of the solar cells are increased by approximately 60%, with a slight increase in the open-circuit voltage. Details are presented. (WHK)
Chu, S. S.
Photovoltaic mechanisms in polycrystalline thin film silicon solar cells. Final report, 30 June 1979-29 June 1980
The objectives of this program were: (1) to develop appropriate measurement techniques to facilitate a quantitative study of the electrical activity of structural defects and at a grain boundary (G.B.) in terms of generation-recombination, barrier height, and G.B. conductivity; (2) to characterize G.B.s in terms of physical properties such as angle of misfit and local stress, and to correlate them with the electrical activity; (3) to determine the influence of solar cell processing on the electrical behavior of structural defects and G.B.s; and (4) to evaluate polycrystalline solar cell performance based on the above study, and to compare it with the experimentally measured performance. Progress is reported in detail. (WHK)
Sopori, B.L.
Correlations of Capacitance-Voltage Hysteresis with Thin-Film CdTe Solar Cell Performance During Accelerated Lifetime Testing
In this paper we present the correlation of CdTe solar cell performance with capacitance-voltage hysteresis, defined presently as the difference in capacitance measured at zero-volt bias when collecting such data with different pre-measurement bias conditions. These correlations were obtained on CdTe cells stressed under conditions of 1-sun illumination, open-circuit bias, and an acceleration temperature of approximately 100 degrees C.
Albin, D.; del Cueto, J.
Atmospheric Pressure Chemical Vapor Deposition of High Silica SiO2-TiO2 Antireflective Thin Films for Glass Based Solar Panels
The atmospheric pressure chemical vapor deposition (APCVD) of SiO2-TiO2 thin films employing [[(tBuO)3Si]2O-Ti(OiPr)2], which can be prepared from commercially available materials, results in antireflective thin films on float glass under industrially relevant manufacturing conditions. It was found that while the deposition temperature had an effect on the SiO2:TiO2 ratio, the thickness was dependent on the time of deposition. This study shows that it is possible to use APCVD employing a single source precursor containing titanium and silicon to produce thin films on float glass with high SiO2:TiO2 ratios.
Klobukowski, Erik R [ORNL; Tenhaeff, Wyatt E [ORNL; McCamy, James [PPG; Harris, Caroline [PPG; Narula, Chaitanya Kumar [ORNL
Research on polycrystalline thin-film materials, cells, and modules
The US Department of Energy (DOE) supports research activities in polycrystalline thin films through the Polycrystalline Thin-Film Program at the Solar Energy Research Institute (SERI). This program includes research and development (R D) in both copper indium diselenide and cadmium telluride thin films for photovoltaic applications. The objective of this program is to support R D of photovoltaic cells and modules that meet the DOE long-term goals of high efficiency (15%--20%), low cost ($50/m{sup 2}), and reliability (30-year life time). Research carried out in this area is receiving increased recognition due to important advances in polycrystalline thin-film CuInSe{sub 2} and CdTe solar cells and modules. These have become the leading thin-film materials for photovoltaics in terms of efficiency and stability. DOE has recognized this potential through a competitive initiative for the development of CuInSe{sub 2} and CdTe modules. This paper focuses on the recent progress and future directions of the Polycrystalline Thin-Film Program and the status of the subcontracted research on these promising photovoltaic materials. 26 refs., 12 figs, 1 tab.
Mitchell, R.L.; Zweibel, K.; Ullal, H.S.
CFN | Thin Films Group
Materials Synthesis and Characterization Facility Materials Synthesis and Characterization Facility Thin-Film Processing Facility Online Manager (FOM) website FOM manual ESR for lab 1L32 (High-Resolution SEM and x-ray microanalysis) CFN Operations Safety Awareness (COSA) form for 1L32 (ESR #1) Technical article on LABE detector (Analytical SEM) Request form for off-hours access (.doc, First time only, renewals done via email) Lab Tool capabilities Primary contact Training schedule Backup contact Booking calendar Booking rules SOP 1L32 Analytical SEM Camino Thurs 10-12 PM Stein FOM yes yes Hitachi S-4800 SEM Stein Tues 1-3 PM Black FOM no yes booking calendar: yes = need to reserve tool time in calendar before using tool booking rules: yes = specific rules exist for reserving tool time SOP = standard operating procedure (basic instructions)
Use of 2nd and 3rd Level Correlation Analysis for Studying Degradation in Polycrystalline Thin-Film Solar Cells
The correlation of stress-induced changes in the performance of laboratory-made CdTe solar cells with various 2nd and 3rd level metrics is discussed. The overall behavior of aggregated data showing how cell efficiency changes as a function of open-circuit voltage (Voc), short-circuit current density (Jsc), and fill factor (FF) is explained using a two-diode, PSpice model in which degradation is simulated by systematically changing model parameters. FF shows the highest correlation with performance during stress, and is subsequently shown to be most affected by shunt resistance, recombination and in some cases voltage-dependent collection. Large decreases in Jsc as well as increasing rates of Voc degradation are related to voltage-dependent collection effects and catastrophic shunting respectively. Large decreases in Voc in the absence of catastrophic shunting are attributed to increased recombination. The relevance of capacitance-derived data correlated with both Voc and FF is discussed.
Albin, D. S.; del Cueto, J. A.; Demtsu, S. H.; Bansal, S.
Molecular beam epitaxy-grown wurtzite MgS thin films for solar-blind ultra-violet detection
Molecular beam epitaxy grown MgS on GaAs(111)B substrate was resulted in wurtzite phase, as demonstrated by detailed structural characterizations. Phenomenological arguments were used to account for why wurtzite phase is preferred over zincblende phase or its most stable rocksalt phase. Results of photoresponse and reflectance measurements performed on wurtzite MgS photodiodes suggest a direct bandgap at around 5.1 eV. Their response peaks at 245 nm with quantum efficiency of 9.9% and enjoys rejection of more than three orders at 320 nm and close to five orders at longer wavelengths, proving the photodiodes highly competitive in solar-blind ultraviolet detection.
Lai, Y. H.; He, Q. L. [Nano Science and Nano Technology Program, The Hong Kong University of Science and Technology, HKSAR, People's Republic of China (China) [Nano Science and Nano Technology Program, The Hong Kong University of Science and Technology, HKSAR, People's Republic of China (China); Department of Physics and William Mong Institute of Nano Science and Technology, The Hong Kong University of Science and Technology, HKSAR, People's Republic of China (China); Cheung, W. Y.; Lok, S. K.; Wong, K. S.; Sou, I. K. [Department of Physics and William Mong Institute of Nano Science and Technology, The Hong Kong University of Science and Technology, HKSAR, People's Republic of China (China)] [Department of Physics and William Mong Institute of Nano Science and Technology, The Hong Kong University of Science and Technology, HKSAR, People's Republic of China (China); Ho, S. K. [Faculty of Science and Technology, University of Macau, Macau, People's Republic of China (China)] [Faculty of Science and Technology, University of Macau, Macau, People's Republic of China (China); Tam, K. W. [Department of Electrical and Electronics Engineering, University of Macau, Macau, People's Republic of China (China)] [Department of Electrical and Electronics Engineering, University of Macau, Macau, People's Republic of China (China)
Solar Energy Materials & Solar Cells 91 (2007) 17261732 Optical and structural properties of Ta2O5CeO2 thin films
Solar Energy Materials & Solar Cells 91 (2007) 17261732 Optical and structural properties of Ta2O5
Thirumalai, Devarajan
Photovoltaic mechanisms in polycrystalline thin film solar cells. Quarterly technical progress report No. 2, January 1, 1979--March 31, 1979
The effect of grain size on short circuit current density was investigated by approximating individual silicon grains as right circular cylinders and solving the diffusion equation within the base region. This model confirms the previous results that for grain radii exceeding a few tenths of a millimeter, the minority carrier lifetime in the grain essentially determines the short-circuit current response of the cell. The dark I-V characteristics of some polycrystalline solar cells were measured and compared with single crystal cells. The dark current of the polycrystalline cells is dominated by recombination within the space-charge region well past the one sun maximum power point. This has the effect of lowering the cells output power and open circuit voltage. Single crystal cells are dominated by recombination within the quasi-neutral regions at the one sun maximum power point and, consequently, the fill factor and open circuit voltage are greater. Additionally, some preliminary measurements of the spatial dependence of diffusion length were made, Laue X-ray diffraction study of crystal orientations was performed and some SEM micrographs of polycrystalline wafers were taken.
Storti, G.; Johnson, S.; Lin, H.C.; Armstrong, R.W.
Amorphous thin films for solar-cell applications. Technical progress report, 11 October 1980 to 15 January 1981
Progress has been ahead of planned expectations in three instances: (a) achievement of 4 mA/cm/sup 2/, short circuit current density in a MIS structure solar cell under AM1 illumination; (b) fabrication of large area (4 cm/sup 2/) MIS cells with external J/sub sc/ > 3 mA/cm/sup 2/; and (c) deposition of p/sup +/ layers by B/sub 2/H/sub 6/ gas phase doping. A program status table is included. Reproducible n layers are now routinely deposited by sputtering in Ar, H/sub 2/, and PH/sub 3/ gases. The major remaining obstacle to the goal of a 3.5% cell is the deposition of a quality i-layer. Although information deduced from infrared absorption and Raman data indicates that most of the hydrogen is bonded in the SiH configuration, the photoconductivity of the intrinsic material requires marked improvement. Two forms of magnetron sputtering, planar and cylindrical, are being exploited. The planar deposition system has the advantage that experimental costs are low; the cylindrical system is easily scalable to large product throughput. Schematic illustrations of the two systems and descriptions of apparatus modifications incorporated are included.
Jonath, A.D.; Anderson, W.W.; Crowley, J.L.; MacMillan H.F. Jr.; Thornton, J.A.
Effects of Cu Diffusion from ZnTe:Cu/Ti Contacts on Carrier Lifetime of CdS/CdTe Thin Film Solar Cells: Preprint
We study the performance of CdS/CdTe thin film PV devices processed with a ZnTe:Cu/Ti contact to investigate how carrier lifetime in the CdTe layer is affected by Cu diffusion from the contact.
Gessert, T. A.; Metzger, W. K.; Asher, S. E.; Young, M. R.; Johnston, S.; Dhere, R. G.; Duda, A.
Thin Film and nanostructure Processing Staff
Thin Film Nanostructure Staff Directory. John Bonevich, Group Leader. Shari Beauchamp, Office Assistant. STAFF & NRC POSTDOCS. ...
Influence of copper to indium atomic ratio on the properties of Cu-In-Te based thin-film solar cells prepared by low-temperature co-evaporation
The influence of copper to indium atomic ratio (Cu/In) on the properties of Cu-In-Te based thin films and solar cells was investigated. The films (Cu/In = 0.38-1.17) were grown on both bare and Mo-coated soda-lime glass substrates at 250 Degree-Sign C by single-step co-evaporation using a molecular beam epitaxy system. Highly (112)-oriented CuInTe{sub 2} films were obtained at Cu/In ratios of 0.84-0.99. However, stoichiometric and Cu-rich films showed a poor film structure with high surface roughness. The films consist of polyhedron-shaped grains, which are related to the coexistence of a Cu{sub 2-x}Te phase, and significant evidence for the coexistence of the Cu{sub 2-x}Te phase in the stoichiometric and Cu-rich films is presented. KCN treatment was performed for the films in order to remove the Cu{sub 2-x}Te phase. The stoichiometric CuInTe{sub 2} thin films exhibited a high mobility above 50 cm{sup 2}/V s at room temperature after the KCN treatment. A preliminary solar cell fabricated using a 1.4-{mu}m-thick Cu-poor CuInTe{sub 2} thin film (Cu/In = 0.84, E{sub g} = 0.988 eV) yielded a total-area efficiency of 2.10%. The photovoltaic performance of the cell was improved after long-term ambient aging in dark conditions.
Mise, Takahiro; Nakada, Tokio [Department of Electrical Engineering and Electronics, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa, 252-5258 (Japan)
New Thin Film CuGaSe2/Cu(In,Ga)Se2 Bifacial, Tandem Solar Cell with Both Junctions Formed Simultaneously
Thin films of CuGaSe2 and Cu(In,Ga)Se2 were evaporated by the 3-stage process onto opposite sides of a single piece of soda-lime glass, coated bifacially with an n+/-TCO. Junctions were formed simultaneously with each of the p-type absorbers by depositing thin films of n-CdS via chemical bath deposition (CBD) at 60C. The resulting four-terminal device is a non-mechanically stacked, two-junction tandem. The unique growth sequence protects the temperature-sensitive p/n junctions. The initial device (h= 3.7%, Voc= 1.1 V[AM1.5]) suffered from low quantum efficiencies. Initial results are also presented from experiments with variations in growth sequence and back reflectors.
Young, D. L.; Abu-Shama, J.; Noufi, R.; Li, X.; Keane, J.; Gessert, T. A.; Ward, J. S.; Contreas, M.; Symko-Davies, M.; Coutts, T. J.
Joint Development of Coated Conductor and Low Cost Thin Film Solar Cells: Cooperative Research and Development Final Report, CRADA Number CRD-007-213
UES plans on developing CIGS thin films by using Metal Organic Deposition (MOD) technique as it is a low-cost, non-vacuum method for scale-up to large area PV modules. NREL will support UES, Inc. through expert processing, characterization and device fabrication. NREL scientists will also help develop a processing phase diagram which includes composition, film thickness, annealing temperature and ambient conditions. Routine measurements of devices and materials will be done under NREL's core support project.
Bhattacharya, R.
All-Hot-Wire Chemical Vapor Deposition a-Si:H Solar Cells
Efficient hydrogenated amorphous silicon (a-Si:H) nip solar cells have been fabricated with all doped and undoped a-Si:H layers deposited by hot-wire chemical vapor deposition (HWCVD). The total deposition time of all layers, except the top ITO-contact, is less than 4 minutes.
Iwaniczko, E.; Wang, Q.; Xu, Y.; Nelson, B. P.; Mahan, A. H.; Crandall, R. S.; Branz, H. M.
Solar Energy Materials & Solar Cells 92 (2008) 821829 Modeling the optical properties of WO3 and WO3SiO2 thin films
Solar Energy Materials & Solar Cells 92 (2008) 821829 Modeling the optical properties of WO3 the optical response of the films in the near-UV and visible region: two interband transitions for energies E
Thin-film Lithium Batteries
Thin-Film Battery with Lithium Anode Courtesy of Oak Ridge National Laboratory, Materials Science and Technology Division Thin-Film Lithium Batteries Resources with Additional Information The Department of Energy's 'Oak Ridge National Laboratory (ORNL) has developed high-performance thin-film lithium batteries for a variety of technological applications. These batteries have high energy densities, can be recharged thousands of times, and are only 10 microns thick. They can be made in essentially any size and shape. Recently, Teledyne licensed this technology from ORNL to make batteries for medical devices including electrocardiographs. In addition, new "textured" cathodes have been developed which have greatly increased the peak current capability of the batteries. This greatly expands the potential medical uses of the batteries, including transdermal applications for heart regulation.'
Thin film-coated polymer webs
The present invention relates to thin film-coated polymer webs, and more particularly to thin film electronic devices supported upon a polymer web, wherein the polymer web is treated with a purifying amount of electron beam radiation.
Wenz, Robert P. (Cottage Grove, MN); Weber, Michael F. (Shoreview, MN); Arudi, Ravindra L. (Woodbury, MN)
Semiconductor-nanocrystal/conjugated polymer thin films
The invention described herein provides for thin films and methods of making comprising inorganic semiconductor-nanocrystals dispersed in semiconducting-polymers in high loading amounts. The invention also describes photovoltaic devices incorporating the thin films.
Alivisatos, A. Paul (Oakland, CA); Dittmer, Janke J. (Munich, DE); Huynh, Wendy U. (Munich, DE); Milliron, Delia (Berkeley, CA)
Thin Film Deposition Method for Sensor Manufacturing
Scientists at Los Alamos National Laboratory (LANL) have developed an innovative method for gas sensor manufacturing using a thin film deposition. The thin film requires very little material and can be applied in high throughput applications.
Fabrication of polycrystalline thin films by pulsed laser processing
A method for fabricating polycrystalline thin films on low-temperature (or high-temperature) substrates which uses processing temperatures that are low enough to avoid damage to the substrate, and then transiently heating select layers of the thin films with at least one pulse of a laser or other homogenized beam source. The pulse length is selected so that the layers of interest are transiently heated to a temperature which allows recrystallization and/or dopant activation while maintaining the substrate at a temperature which is sufficiently low to avoid damage to the substrate. This method is particularly applicable in the fabrication of solar cells.
Mitlitsky, Fred (Livermore, CA); Truher, Joel B. (San Rafael, CA); Kaschmitter, James L. (Pleasanton, CA); Colella, Nicholas J. (Livermore, CA)
A method is disclosed for fabricating polycrystalline thin films on low-temperature (or high-temperature) substrates which uses processing temperatures that are low enough to avoid damage to the substrate, and then transiently heating select layers of the thin films with at least one pulse of a laser or other homogenized beam source. The pulse length is selected so that the layers of interest are transiently heated to a temperature which allows recrystallization and/or dopant activation while maintaining the substrate at a temperature which is sufficiently low to avoid damage to the substrate. This method is particularly applicable in the fabrication of solar cells. 1 fig.
Mitlitsky, F.; Truher, J.B.; Kaschmitter, J.L.; Colella, N.J.
Thin film cadmium telluride photovoltaic cells
This report describes research to develop to vacuum-based growth techniques for CdTe thin-film solar cells: (1) laser-driven physical vapor deposition (LDPVD) and (2) radio-frequency (rf) sputtering. The LDPVD process was successfully used to deposit thin films of CdS, CdTe, and CdCl{sub 2}, as well as related alloys and doped semiconductor materials. The laser-driven deposition process readily permits the use of several target materials in the same vacuum chamber and, thus, complete solar cell structures were fabricated on SnO{sub 2}-coated glass using LDPVD. The rf sputtering process for film growth became operational, and progress was made in implementing it. Time was also devoted to enhancing or implementing a variety of film characterization systems and device testing facilities. A new system for transient spectroscopy on the ablation plume provided important new information on the physical mechanisms of LDPVD. The measurements show that, e.g., Cd is predominantly in the neutral atomic state in the plume but with a fraction that is highly excited internally ({ge} 6 eV), and that the typical neutral Cd translational kinetic energies perpendicular to the target are 20 eV and greater. 19 refs.
Compaan, A.; Bohn, R. (Toledo Univ., OH (United States))
Magnetoelectric Multiferroic Thin Films and Multilayers
Scope, The symposium will cover thin films, single crystals, normal/relaxor ferroelectrics, piezoelectric ceramics, magnetoelectric composites, multiferroic�...
Magnetic behaviour of europium epitaxial thin films
... Magnetic behaviour of europium epitaxial thin films. Philippe Mangin, University of Nancy and NCNR. We present the magnetic ...
MST: Organizations: Thin Film, Vacuum, and Packaging
Processes & Services Electronic Fabrication Manufacturing Process Science & Technology Thin Film, Vacuum, & Packaging Organic Materials Ceramic & Glass Meso Manufacturing &...
Electronic processes in thin-film PV materials. Final report
The electronic and optical processes in an important class of thin-film PV materials, hydrogenated amorphous silicon (a-Si:H) and related alloys, have been investigated using several experimental techniques designed for thin-film geometries. The experimental techniques include various magnetic resonance and optical spectroscopies and combinations of these two spectroscopies. Two-step optical excitation processes through the manifold of silicon dangling bond states have been identifies as important at low excitation energies. Local hydrogen motion has been studied using nuclear magnetic resonance techniques and found to be much more rapid than long range diffusion as measured by secondary ion mass spectroscopy. A new metastable effect has been found in a-Si:H films alloyed with sulfur. Spin-one optically excited states have been unambiguously identified using optically detected electron spin resonance. Local hydrogen bonding in microcrystalline silicon films has been studied using NMR.
Taylor, P.C.; Chen, D.; Chen, S.L. [and others
Thin film photovoltaic cells
A solar cell has as its transparent electrical contact a grid made from a non-noble metal by providing a layer of copper oxide between the transparent electrical contact and the absorber-generator.
Rothwarf, Allen (Philadelphia, PA)
Defect engineering of cuprous oxide thin-films for photovoltaic applications
Thin-film solar cells are promising for renewable-energy applications due to their low material usage and inexpensive manufacturing potential, making them compatible with terawatts-level deployment. Cuprous oxide (Cu?O) ...
Lee, Yun Seog
Impact of solid-phase crystallization of amorphous silicon on the chemical structure of the buried Si/ZnO thin film solar cell interface
The chemical interface structure between phosphorus-doped hydrogenated amorphous silicon and aluminum-doped zinc oxide thin films is investigated with soft x-ray emission spectroscopy (XES) before and after solid-phase crystallization (SPC) at 600C. In addition to the expected SPC-induced phase transition from amorphous to polycrystalline silicon, our XES data indicates a pronounced chemical interaction at the buried Si/ZnO interface. In particular, we find an SPC-enhanced formation of Si-O bonds and the accumulation of Zn in close proximity to the interface. For an assumed closed and homogeneous SiO2 interlayer, an effective thickness of (5+2)nm after SPC could be estimated.
Bar, M.; Wimmer, M.; Wilks, R. G.; Roczen, M.; Gerlach, D.; Ruske, F.; Lips, K.; Rech, B.; Weinhardt, L.; Blum, M.; Pookpanratana, S.; Krause, S.; Zhang, Y.; Heske, C.; Yang, W.; Denlinger, J. D.
Excess Dark Currents and Transients in Thin-Film CdTe Solar Cells: Implications for Cell Stability and Encapsulation of Scribe Lines and Cell Ends in Modules
We have isolated a non-linear, metastable, shunt-path failure mechanism located at the CdS/CdTe cell edge. In such cases, most performance loss, usually erratic, can be associated with the shunt path. We studied these shunt paths using dark current-transients and infrared (ir) imaging and find only one shunt path per cell and only at the cell corner wall, even in badly degraded cells. The effect on diminishing the cell's efficiency far exceeds what would be expected from the cell's linear shunt-resistance value. We propose that current transients and ir imaging be used as a ''fingerprint'' of the source and magnitude of excess currents to evaluate the contribution of scribe-line edges and cell ends in thin-film module performance and degradation due to environmental stress. Protection afforded by, or contamination due to, new or currently used encapsulants can then be evaluated.
McMahon, T. J.; Berniard, T. J.; Albin, D. S.; Demtsu, S. H.
Comparison Between Research-Grade SnO2 and Commercial Available SnO2 for Thin-Film CdTe Solar Cell (Poster)
A comparison between research-grade, tin-oxide (SnO{sub 2}) thin films and those available from commercial sources is performed. The research-grade SnO{sub 2} film is fabricated at NREL by low-pressure metal-organic chemical vapor deposition. The commercial SnO{sub 2} films are Pilkington Tec 8 and Tec 15 fabricated by atmospheric-pressure chemical vapor deposition. Optical, structural, and compositional analyses are performed. From the optical analysis, an estimation of the current losses due to the SnO{sub 2} layer and glass is provided. Our analysis indicates that the optical properties of commercial SnO{sub 2} could be improved for PV usage.
Li, X.; Pankow, J.; To, B.; Gessert, T.
Photovoltaic Single-Crystalline, Thin-Film Cell Basics | Department of
Single-Crystalline, Thin-Film Cell Basics Single-Crystalline, Thin-Film Cell Basics Photovoltaic Single-Crystalline, Thin-Film Cell Basics August 20, 2013 - 2:50pm Addthis Single-crystalline thin films are made from gallium arsenide (GaAs), a compound semiconductor that is a mixture of gallium and arsenic. Gallium arsenide (GaAs) is a compound semiconductor, a mixture of gallium and arsenic. Gallium is a byproduct of the smelting of other metals, notably aluminum and zinc, and it is rarer than gold. Arsenic is not rare, but it is poisonous. Gallium arsenide has been developed for use in solar cells at about the same time that it has been developed for light-emitting diodes, lasers, and other electronic devices that use light. GaAs solar cells offer several benefits: The GaAs bandgap is 1.43 eV-nearly ideal for single-junction solar
NREL: Energy Analysis - Crystalline Silicon and Thin Film Photovoltaic
Crystalline Silicon and Thin Film Photovoltaic Results - Life Cycle Crystalline Silicon and Thin Film Photovoltaic Results - Life Cycle Assessment Harmonization Life Cycle Greenhouse Gas Emissions from Solar Photovoltaics (Fact Sheet) Cover of the Life Cycle Greenhouse Gas Emissions from Solar Photovoltaics factsheet Download the Fact Sheet Over the last 30 years, hundreds of life cycle assessments (LCAs) have been conducted and published for a variety of residential and utility-scale solar photovoltaic (PV) systems with wide-ranging results. The inconsistencies in these results can be attributed to the technologies evaluated-such as differing system designs, real-world versus conceptual systems, or technology improvements over time-and life cycle assessment methods and assumptions. To better understand greenhouse gas (GHG) emissions from commercial
CdSiAs/sub 2/ thin films for solar cell applications. First quarter report April 9, 1979-June 30, 1979
Near stoichiometric bulk polycrystalline CdSiAs/sub 2/ has been synthesized by two techniques: (1) direct fusion of the elements and (2) direct fusion of the binaries SiAs, Cd/sub 3/As/sub 2/ and CdAs/sub 2/. The latter technique resulted in denser ternary material with good homogeneity. The above binaries melt congruently and were also formed by direct fusion. Sputtered ternary films were formed using a bulk CdSiAs/sub 2/ target, and a composite target of CdAs/sub 2/ discs in a Si plate. Composition of the CdSiAS/sub 2/ target changed with sputtering time. Amorphous films deposited from that target were heat treated, and became crystalline and near stoichiometric but with poor mechanical properties. It appears that films deposited from the composite target (Si + CdAs/sub 2/) can be adjusted to stoichiometry by means of sputtering power and target geometry. As deposited, these films also were amorphous. With respect to evaporated films, the study of thermal decomposition of CdSiAs/sub 2/ in vacuum was completed. The decomposition is preferential toward Cd between 570/sup 0/ and 710/sup 0/C, and toward As in the 710 to 1010/sup 0/C range. It is concluded that evaporation of the ternary is not a suitable method for forming CdSiAs/sub 2/ films. Plans for the next reporting period include continued sputtering studies with the composite target, constructing a two-source setup for evaporated films, expanded film characterization and fabrication of bulk CdSiAs/sub 2//CdS solar cells.
Disclosed is a thin film heterojunction solar cell, said heterojunction comprising a p-type I-III-IV[sub 2] chalcopyrite substrate and an overlying layer of an n-type ternary mixed metal compound wherein said ternary mixed metal compound is applied to said substrate by introducing the vapor of a first metal compound to a vessel containing said substrate from a first vapor source while simultaneously introducing a vapor of a second metal compound from a second vapor source of said vessel, said first and second metals comprising the metal components of said mixed metal compound; independently controlling the vaporization rate of said first and second vapor sources; reducing the mean free path between vapor particles in said vessel, said gas being present in an amount sufficient to induce homogeneity of said vapor mixture; and depositing said mixed metal compound on said substrate in the form of a uniform composition polycrystalline mixed metal compound. 5 figs.
Performance of Hydrogenated a-Si:H Solar Cells with Downshifting Coating: Preprint
We apply a thin luminescent downshifting (LDS) coating to a hydrogenated amorphous Si (a-Si:H) solar cell and study the mechanism of possible current enhancement. The conversion material used in this study converts wavelengths below 400 nm to a narrow line around 615 nm. This material is coated on the front of the glass of the a-Si:H solar cell with a glass/TCO/p/i/n/Ag superstrate configuration. The initial efficiency of the solar cell without the LDS coating is above 9.0 % with open circuit voltage of 0.84 V. Typically, the spectral response below 400 nm of an a-Si:H solar cell is weaker than that at 615 nm. By converting ultraviolet (UV) light to red light, the solar cell will receive more red photons; therefore, solar cell performance is expected to improve. We observe evidence of downshifting in reflectance spectra. The cell Jsc decreases by 0.13 mA/cm2, and loss mechanisms are identified.
Nemeth, B.; Xu, Y.; Wang, H.; Sun, T.; Lee, B. G.; Duda, A.; Wang, Q.
Thin-film CdTe and CuInSe{sub 2} photovoltaic technologies
Total-area conversion efficiency of 15%--15.8% have been achieved for thin-film CdTe and CIS solar cells. Modules with power output of 5--53 W have been demonstrated by several groups world-wide. Critical processes and reaction pathways for achieving excellent PV devices have been eluciated. Research, development and technical issues have been identified, which could result in potential improvements in device and module performance. A 1-kW thin-film CdTe array has been installed and is being tested. Multimegawatt thin-film CdTe manufacturing plants are expected to be completed in 1-2 years.
Ullal, H.S.; Zweibel, K.; von Roedern, B.G.
Method of producing amorphous thin films
Disclosed is a method of producing thin films by sintering which comprises: a. coating a substrate with a thin film of an inorganic glass forming parulate material possessing the capability of being sintered, and b. irridiating said thin film of said particulate material with a laser beam of sufficient power to cause sintering of said material below the temperature of liquidus thereof. Also disclosed is the article produced by the method claimed.
Brusasco, Raymond M. (Livermore, CA)
Development of a computer model for polycrystalline thin-film CuInSe{sub 2} and CdTe solar cells; Annual subcontract report, 1 March 1992--28 February 1993
Solar cells operate by converting the radiation power from sun light into electrical power through photon absorption by semiconductor materials. The elemental and compound material systems widely used in photovoltaic applications can be produced in a variety of crystalline and non-crystalline forms. Although the crystalline group of materials have exhibited high conversion efficiencies, their production cost are substantially high. Several candidates in the poly- and micro-crystalline family of materials have recently gained much attention due to their potential for low cost manufacturability, stability, reliability and good performance. Among those materials, CuInSe{sub 2} and CdTe are considered to be the best choices for production of thin film solar cells because of the good optical properties and almost ideal band gap energies. Considerable progress was made with respect to cell performance and low cost manufacturing processes. Recently conversion efficiencies of 14.1 and 14.6% have been reported for CuInSe{sub 2} and CdTe based solar cells respectively. Even though the efficiencies of these cells continue to improve, they are not fully understood materials and there lies an uncertainty in their electrical properties and possible attainable performances. The best way to understand the details of current transport mechanisms and recombinations is to model the solar cells numerically. By numerical modeling, the processes which limit the cell performance can be sought and therefore, the most desirable designs for solar cells utilizing these materials as absorbers can be predicted. The problems with numerically modeling CuInSe{sub 2} and CdTe solar cells are that reported values of the pertinent material parameters vary over a wide range, and some quantities such as carrier concentration are not explicitly controlled.
Gray, J.L.; Schwartz, R.J.; Lee, Y.J. [Purdue Univ., West Lafayette, IN (United States)
This invention dicloses a method for sintering particulate material (such as silica) with a laser beam to produce amorphous optical thin films on substrates.
Brusasco, R.M.
Infrared Analysis of Advanced Thin Film Materials
The goals of timely and cost effective integration of these new materials into ... most widely accepted method for production monitoring of transparent thin films.
Enhanced Thin Film Organic Photovoltaic Devices
A novel structure design for thin film organic photovoltaic (OPV) devices provides a system for increasing the optical absorption in the active layer. ...
Characterization of Micro-, Nano-, and Thin Films
Feb 18, 2010... CdS:In Thin Films Prepared by the Spray-Pyrolysis Technique: Shadia Ikhmayies1; Riyad Ahmad-Bitar1; 1University of Jordan
Mechanical Properties of Thin Film Metallic Glass
Because of these and other properties, thin film metallic-glasses (TFMGs) are a promising structural material for fabricating the next generation of micro- and�...
Textured Ultrafine Grained Al Thin Films
Symposium, Fatigue and Fracture of Thin Films and Nanomaterials. Presentation Title, In-Situ ACOM-TEM Nanomechanical Testing of Textured Ultrafine�...
Surface Sensitive Scattering from Thin Films
... Thin films of few tenths of angstroms are becoming the staple of the electronic ... a powerful tool for the basic understanding of the film microstructure. ...
Polycrystalline thin-film module and system performance
The Module and System Performance and Engineering Project at the National Renewable Energy Laboratory (NREL) conducts in-situ technical evaluations of photovoltaic (PV) modules and systems (arrays). These evaluations on module/array performance and stability are conducted at the NREL Photovoltaic Outdoor Test Facility (OTF) in Golden, CO. The modules and arrays are located at 39.7{degree}N latitude, 105.2{degree}W longitude, and at 1,782 meters elevation. Currently, two polycrystalline thin-film technologies are the focus of the research presented here. The module structures are copper indium diselenide (CIS) from Siemens Solar Industries and cadmium telluride (CdTe) from Solar Cells, Inc. The research team is attempting to correlate individual module performance with array performance for these two polycrystalline thin-film technologies. This is done by looking at module and array performance over time. Also, temperature coefficients are determined at both the module and array level. Results are discussed.
Strand, T.; Kroposki, B.; Hansen, R.; Mrig, L.
Thin film buried anode battery
A reverse configuration, lithium thin film battery (300) having a buried lithium anode layer (305) and process for making the same. The present invention is formed from a precursor composite structure (200) made by depositing electrolyte layer (204) onto substrate (201), followed by sequential depositions of cathode layer (203) and current collector (202) on the electrolyte layer. The precursor is subjected to an activation step, wherein a buried lithium anode layer (305) is formed via electroplating a lithium anode layer at the interface of substrate (201) and electrolyte film (204). The electroplating is accomplished by applying a current between anode current collector (201) and cathode current collector (202).
Lee, Se-Hee (Lakewood, CO); Tracy, C. Edwin (Golden, CO); Liu, Ping (Denver, CO)
Thin-Film Photovoltaic Industry
This report presents an overview of the thin-film (TF) photovoltaic (PV) industry as of the third quarter of 2012, a time in the midst of very rapid changes.� The TFPV industry has seen significantly greater investment in the past 5 to 10 years than in any previous time and up until recently it seemed that this investment was on track to make TFPV a much larger player in the overall PV market.� However, market dynamics have conspired to dim TFPV�s near-term prospects and ...
Thin-film optical initiator - Energy Innovation Portal
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.
Optical Design and Analysis of Textured a-Si Solar Cells: Preprint
The effect of texture on enhancement and losses in photocurrent in a-Si solar cells is explored using PVOPTICS software and measurements on a-Si device structures. The texture angle has a major impact on light trapping and internal reflection. Increasing the angle causes better internal trapping in the i-layer, but also higher SnO2/a-Si reflection losses, as well as SnO2 and metal absorption losses. Parasitic absorption in the textured SnO2 due to back reflected light is 1-2 mA/cm2 for typical designs. N-i-p cells have a fundamental advantage over p-i-n cells since the textured TCO is at the rear of the device leading to lower losses.
Hegedus, S.; Paulson, P. D.; Sopori, B.
Stable a-Si:H-Based Multijunction Solar Cells with Guidance from Real-Time Optics: Final Report, 17 July 1998--16 November 2001
This report describes the new insights obtained into the growth of hydrogenated silicon (Si:H) films via real-time spectroscopic ellipsometry (RTSE) measurements. Evolutionary phase diagrams were expanded to include the effects of different deposition conditions, including rf power, pressure, and temperature. Detailed studies of degradation kinetics in thin films and corresponding solar cells have been carried out. Both p-i-n and n-i-p solar cells that incorporate Si:H i-layers deposited with and without H2-dilution have been studied. For the first time, direct and reliable correlations have been obtained between the light-induced changes in thin-film materials and the degradation of the corresponding solar cells.
Wronski, C. R.; Collins, R. W.; Pearce, J. M.; Koval, R. J.; Ferlauto, A. S.; Ferreira, G. M.; Chen C.
Daylighting control performance of a thin-film ceramic electrochromic...
Daylighting control performance of a thin-film ceramic electrochromic window: Field study results Title Daylighting control performance of a thin-film ceramic electrochromic...
Breakthroughs in Thin-Film Magnetic Devices Earn NIST ...
... thin films to control magnetism as a foundation for developing better sensors and memory devices. Computer hard drives that use magnetic thin-film ...
Amorphous and nanocrystalline Mg2Si thin-film electrodes
Contact Us Department Contacts Media Contacts Amorphous and nanocrystalline Mg2Si thin-film electrodes Title Amorphous and nanocrystalline Mg2Si thin-film electrodes...
Thin-Film/Low-K Dielectric Constant Measurement
... to pursue a very different approach to dielectric thin-film characterization at ... at NIST; DOW will simply deposit and pattern the thin films on pretested ...
NREL: Photovoltaics Research - Polycrystalline Thin-Film Materials...
in the area of polycrystalline thin-film materials and devices. Printable Version Photovoltaics Research Home Silicon Polycrystalline Thin Films Multijunctions New Materials,...
Oxynitride Thin Film Barriers for PV Packaging
Dielectric thin-film barrier and adhesion-promoting layers consisting of silicon oxynitride materials (SiOxNy, with various stoichiometry) were investigated. For process development, films were applied to glass (TCO, conductive SnO2:F; or soda-lime), polymer (PET, polyethylene terephthalate), aluminized soda-lime glass, or PV cell (a-Si, CIGS) substrates. Design strategy employed de-minimus hazard criteria to facilitate industrial adoption and reduce implementation costs for PV manufacturers or suppliers. A restricted process window was explored using dilute compressed gases (3% silane, 14% nitrous oxide, 23% oxygen) in nitrogen (or former mixtures, and 11.45% oxygen mix in helium and/or 99.999% helium dilution) with a worst-case flammable and non-corrosive hazard classification. Method employed low radio frequency (RF) power, less than or equal to 3 milliwatts per cm2, and low substrate temperatures, less than or equal to 100 deg C, over deposition areas less than or equal to 1000 cm2. Select material properties for barrier film thickness (profilometer), composition (XPS/FTIR), optical (refractive index, %T and %R), mechanical peel strength and WVTR barrier performance are presented.
Glick, S. H.; delCueto, J. A.; Terwilliger, K. M.; Jorgensen, G. J.; Pankow, J. W.; Keyes, B. M.; Gedvilas, L. M.; Pern, F. J.
Organic thin film prehistory: looking towards solution phase aggregation |
Organic thin film prehistory: looking towards solution phase aggregation Organic thin film prehistory: looking towards solution phase aggregation Wednesday, November 6, 2013 - 3:00pm SLAC, Redtail Hawk Conference Room 108A Christopher Tassone, SSRL Polymer bulk heterojunction (BHJ) solar cells have attracted significant attention in industry and academia because of their potential for achieving large-area, light-weight, and flexible photovoltaic devices through cost-effective solution deposition techniques. These devices consist of a blend of an absorbing polymer and an electron accepting fullerene, the molecular packing and phase segregation of which heavily influence power conversion efficiency by effecting important processes such as exciton splitting, charge transport, and recombination. Understanding and utilization of molecular interactions to predicatively control the
Electrical Properties of Point Defects in CdS and ZnS Thin-film PV ...
... Electrical Properties of Point Defects in CdS and ZnS Thin-film PV Buffer ... but whose band gap is too small for complete transparency to solar radiation.
Aging phenomena in polystyrene thin films
The aging behavior is investigated for thin films of atactic polystyrene through measurements of complex electric capacitance. During isothermal aging process the real part of the electric capacitance increases with aging time, while the imaginary part decreases with aging time. This result suggests that the aging time dependence of the real and imaginary parts are mainly associated with change in thickness and dielectric permittivity, respectively. In thin films, the thickness depends on thermal history of aging even above the glass transition. Memory and `rejuvenation' effects are also observed in the thin films.
Koji Fukao; Hiroki Koizumi
Development of a computer model for polycrystalline thin-film CuInSe sub 2 and CdTe solar cells
This report describes work to develop a highly accurate numerical model for CuInSe{sub 2} and CdTe solar cells. ADEPT (A Device Emulation Program and Toolbox), a one-dimensional semiconductor device simulation code developed at Purdue University, was used as the basis of this model. An additional objective was to use ADEPT to analyze the performance of existing and proposed CuInSe{sub 2} and CdTe solar cell structures. The work is being performed in two phases. The first phase involved collecting device performance parameters, cell structure information, and material parameters. This information was used to construct the basic models to simulate CuInSe{sub 2} and CdTe solar cells. This report is a tabulation of information gathered during the first phase of this project on the performance of existing CuInSe{sub 2} and CdTe solar cells, the material properties of CuInSr{sub 2}, CdTe, and CdS, and the optical absorption properties of CuInSe{sub 2}, CdTe, and CdS. The second phase will entail further development and the release of a version of ADEPT tailored to CuInSe{sub 2} and CdTe solar cells that can be run on a personal computer. In addition, ADEPT will be used to analyze the performance of existing and proposed CuInSe{sub 2} and CdTe solar cell structures. 110 refs.
Gray, J.L.; Schwartz, R.J.; Lee, Y.J. (Purdue Univ., Lafayette, IN (United States))
Innovative Thin Films LLC | Open Energy Information
Thin Films LLC Thin Films LLC Jump to: navigation, search Name Innovative Thin Films LLC Place Toledo, Ohio Zip 43607 Product Provider of altnernative energy thin film deposition technology. Coordinates 46.440613°, -122.847838° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":46.440613,"lon":-122.847838,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}
Polycrystalline Thin Film Used in Photovoltaics
Energy.gov (U.S. Department of Energy (DOE))
Polycrystalline thin-film cells are made of many tiny crystalline grains of semiconductor materials. The materials used in these cells have properties that are different from those of silicon.
Solid State Thin Film Lithium Microbatteries
Solid state thin film lithium microbatteries fabricated by pulsed-laser deposition (PLD) are suggested. During deposition the following process parameters must be considered, which are laser energy and fluence, laser pulse ...
Shi, Z.
Superhydrophobic Thin Film Symposium | ornl.gov
Connect with ORNL | For Industry | Partnerships | Events and Conferences Superhydrophobic Thin Film Symposium Sep 05 2012 12:00 AM - 05:00 PM Hosted by Oak Ridge Laboratory's...
Thin films for geothermal sensing: Final report
The report discusses progress in three components of the geothermal measurement problem: (1) developing appropriate chemically sensitive thin films; (2) discovering suitably rugged and effective encapsulation schemes; and (3) conducting high temperature, in-situ electrochemical measurements. (ACR)
This report describes work to develop an accurate numerical model for CuInSe{sub 2} (CIS) and CdTe-based solar cells capable of running on a personal computer. Such a model will aid researchers in designing and analyzing CIS- and CdTe-based solar cells. ADEPT (A Device Emulation Pregrain and Tool) was used as the basis for this model. An additional objective of this research was to use the models developed to analyze the performance of existing and proposed CIS- and CdTe-based solar cells. The development of accurate numerical models for CIS- and CdTe-based solar cells required the compilation of cell performance data (for use in model verification) and the compilation of measurements of material parameters. The development of the numerical models involved implementing the various physical models appropriate to CIS and CdTe, as well as some common window. A version of the model capable of running on an IBM-comparable personal computer was developed (primary code development is on a SUN workstation). A user-friendly interface with pop-up menus is continuing to be developed for release with the IBM-compatible model.
Development of high-efficiency, thin-film CdTe solar cells. Final subcontract report, 1 February 1992--30 November 1995
This report describes work performed by the Georgia Institute of Technology (GIT) to bring the polycrystalline CdTe cell efficiency a step closer to the practically achievable efficiency of 18% through fundamental understanding of detects and loss mechanisms, the role of chemical and heat treatments, and investigation of now process techniques. The objective was addressed by a combination of in-depth characterization, modeling, materials growth, device fabrication, and `transport analyses of Au/Cu/CdTe/CdS/SnO {sub 2} glass front-wall heterojunction solar cells. GiT attempted to understand the loss mechanism(s) in each layer and interface by a step-by-step investigation of this multilayer cell structure. The first step was to understand, quantify, and reduce the reflectance and photocurrent loss in polycrystalline CdTe solar calls. The second step involved the investigation of detects and loss mechanisms associated with the CdTe layer and the CdTe/CdS interface. The third stop was to investigate the effect of chemical and heat treatments on CdTe films and cells. The fourth step was to achieve a better and reliable contact to CdTe solar cells by improving the fundamental understanding. Of the effects of Cu on cell efficiency. Finally, the research involved the investigation of the effect of crystallinity and grain boundaries on Cu incorporation in the CdTe films, including the fabrication of CdTe solar calls with larger CdTe grain size.
Rohatgi, A.; Chou, H.C.; Kamra, S.; Bhat, A. [Georgia Inst. of Tech., Atlanta, GA (United States)
Ultra-high current density thin-film Si diode
A combination of a thin-film .mu.c-Si and a-Si:H containing diode structure characterized by an ultra-high current density that exceeds 1000 A/cm.sup.2, comprising: a substrate; a bottom metal layer disposed on the substrate; an n-layer of .mu.c-Si deposited the bottom metal layer; an i-layer of .mu.c-Si deposited on the n-layer; a buffer layer of a-Si:H deposited on the i-layer, a p-layer of .mu.c-Si deposited on the buffer layer; and a top metal layer deposited on the p-layer.
Wang; Qi (Littleton, CO)
Structure of Silicon-Based Thin Film Solar Cell Materials: Annual Technical Progress Report, 1 April 2002--31 August 2003
The purpose of this research is to achieve a better understanding to improve materials used as the intrinsic layers of amorphous and microcrystalline silicon-based solar cells. Fundamental structural properties will be investigated on atomic and nano-scales. A powerful combination of techniques will be used: analytical high-resolution transmission electron microscopy (HRTEM), including special associated spectroscopic methods, small-angle scattering techniques (SAXS, ASAXS, SANS), and conventional wide-angle X-ray diffraction (XRD).
Williamson, D. L.
Structural Ordering and its Correlation to the Optoelectronic Properties of a-Si:H Films
Magnetic susceptibility was suggested theoretically to be sensitive to the overall structural order of a-Si:H and is measured precisely for various a-Si:H thin films using a new technique.
Baugh, J.; Han, D.; Kleinhammes, A.; Wang, Q.; Wu, Y.
Investigations of CuInSe sub 2 thin films and contacts
This report describes research into electrical contacts for copper indium diselenide (CuInSe{sub 2}) polycrystalline thin films used for solar cell applications. Molybdenum contacts have historically been the most promising for heterojunction solar cells. This program studied contact stability by investigating thermally induced bilayer reactions between molybdenum and copper, indium, and selenium. Because selenization is widely used to fabricate CuInSe{sub 2} thin films for photovoltaic cells, a second part of the program investigated how the morphologies, phases, and reactions of pre-selenization Cu-In structures are affected by the deposition process and heat treatments. 7 refs., 6 figs.
Nicolet, M.A. (California Inst. of Tech., Pasadena, CA (United States))
Ambient pressure process for preparing aerogel thin films reliquified sols useful in preparing aerogel thin films
A method for preparing aerogel thin films by an ambient-pressure, continuous process. The method of this invention obviates the use of an autoclave and is amenable to the formation of thin films by operations such as dip coating. The method is less energy intensive and less dangerous than conventional supercritical aerogel processing techniques.
Brinker, Charles Jeffrey (Albuquerque, NM); Prakash, Sai Sivasankaran (Minneapolis, MN)
Method for producing textured substrates for thin-film photovoltaic cells
The invention pertains to the production of ceramic substrates used in the manufacture of thin-film photovoltaic cells used for directly converting solar energy to electrical energy. Elongated ribbon-like sheets of substrate precursor containing a mixture of ceramic particulates, a binder, and a plasticizer are formed and then while green provided with a mechanically textured surface region used for supporting the thin film semiconductor of the photovoltaic cell when the sheets of the substrate precursor are subsequently cut into substrate-sized shapes and then sintered. The textured surface pattern on the substrate provides enhanced light trapping and collection for substantially increasing the, solar energy conversion efficiency of thin-film photovoltaic cells.
Lauf, Robert J. (Oak Ridge, TN)
The invention pertains to the production of ceramic substrates used in the manufacture of thin-film photovoltaic cells used for directly converting solar energy to electrical energy. Elongated ribbon-like sheets of substrate precursor containing a mixture of ceramic particulates, a binder, and a plasticizer are formed and then while green provided with a mechanically textured surface region used for supporting the thin film semiconductor of the photovoltaic cell when the sheets of the substrate precursor are subsequently cut into substrate-sized shapes and then sintered. The textured surface pattern on the substrate provides enhanced light trapping and collection for substantially increasing the, solar energy conversion efficiency of thin-film photovoltaic cells. 4 figs.
Lauf, R.J.
The invention pertains to the production of ceramic substrates used in the manufacture of thin-film photovoltaic cells used for directly converting solar energy to electrical energy. Elongated ribbon-like sheets of substrate precursor containing a mixture of ceramic particulates, a binder, and a plasticizer are formed and then while green provided with a mechanically textured surface region used for supporting the thin film semiconductor of the photovoltaic cell when the sheets of the substrate precursor are subsequently cut into substrate-sized shapes and then sintered. The textured surface pattern on the substrate provides enhanced light trapping and collection for substantially increasing the solar energy conversion efficiency of thin-film photovoltaic cells.
The invention pertains to the production of ceramic substrates used in the manufacture of thin-film photovoltaic cells used for directly converting solar energy to electrical energy. Elongated ribbon-like sheets of substrate precursor containing a mixture of ceramic particulates, a binder, and a plasticizer are formed and then while green provided with a mechanically textured surface region used for supporting the thin film semiconductor of the photovoltaic cell when the sheets of the substrate precursor are subsequently cut into substrate-sized shapes and then sintered. The textured surface pattern on the substrate provides enhanced light trapping and collection for substantially increasing the solar energy conversion efficiency of thin-film photovoltaic cells. 4 figures.
Disilane versus monosilane: a comparison of the properties of glow-discharge a-Si:H films and solar cells
The consequences of using disilane instead of silane for the glow-discharge deposition of a-Si:H solar cells have been studied. Deposition rates were increased fivefold by the use of disilane. The a-Si:H films have a higher hydrogen content, but otherwise are quite similar to silane produced films and possess the same type of gap states. Chlorosilanes, HCl, and oxysilanes were detected in the disilane by mass spectrometry and their influence on film and solar cell properties assessed. The problem of inadvertent dopant tails resulting from the higher deposition rate of the solar cells is identified.
Delahoy, A.E.; Kampas, F.J.; Corderman, R.R.; Vanier, P.E.; Griffith, R.W.
Disilane versus monosilane: a comparison of the properties of glow-discharge a-Si:H Films and solar cells
Delahoy, A.E.; Corderman, R.R.; Griffith, R.W.; Kampas, F.J.; Vanier, P.E.
Thin Film Absorbers Based on Plasmonic Phase Resonances
We demonstrate an efficient double-layer light absorber by exciting plasmonic phase resonances. We show that the addition of grooves can cause mode splitting of the plasmonic waveguide cavity modes and all the new resonant modes exhibit large absorptivity greater than 90%. Some of the generated absorption peaks have wide-angle characteristics. Furthermore, we find that the proposed structure is fairly insensitive to the alignment error between different layers. The proposed plasmonic nano-structure designs may have exciting potential applications in thin film solar cells, thermal emitters, novel infrared detectors, and highly sensitive bio-sensors.
Cui, Yanxia; Xu, Jun; He, Sailing; Fang, Nicholas X
Advanced processing technology for high-efficiency thin-film CuInSe{sub 2} solar cells. Annual subcontract report, 1 March 1992--28 February 1993
This report describes work to develop novel fabrication for CuInSe{sub 2} (CIS) solar cells that will result in improved performance and cost effectiveness at the manufacturing level. The primary approach involves all solid-state processing for CIS. This was augmented by work to provide novel alternatives for the formation of the window layer/heterojunction contact. Inherent to the project was the need to develop a generic understanding of the relationship between processing and performance so that broad-based transfer to industry can be facilitated. We achieved good-electronic-quality CIS by the use of two selenization procedures for predeposited metal layers. We achieved good stoichiometry throughout the bulk of the film, attained grain sizes of up to 1 {mu}m, and measured electron mobilities of up to 60 cm{sup 2}V-s. However, there is a complex relationship between grain size, adhesion, and performance. Our primary approach to characterization was to fabricate ZnO/CIS test devices and measure as many properties as possible in device format. We are also developing reactive sputtering of ZnO as an alternative window layer technology.
Morel, D.L.; Attar, G.; Karthikeyan, S.; Muthaiah, A.; Zafar, A. [University of South Florida, Tampa, FL (United States)
High-efficiency cadmium and zinc-telluride-based thin-film solar cells. Annual subcontract report, 1 March 1990--28 February 1991
Rohatgi, A.; Sudharsanan, R.; Ringel, S. [Georgia Inst. of Tech., Atlanta, GA (United States)
2008 Solar Technologies Market Report
investments. Thin Film PV Solar Heating & Cooling Projectused in the report. Solar water heating, space heating ande.g. , PV, CSP, solar water heating) Types of industry
Price, S.
Silicon Oxynitride Thin Film Barriers for PV Packaging (Poster)
Dielectric, adhesion-promoting, moisture barriers comprised of silicon oxynitride thin film materials (SiOxNy with various material stoichiometric compositions x,y) were applied to: 1) bare and pre-coated soda-lime silicate glass (coated with transparent conductive oxide SnO2:F and/or aluminum), and polymer substrates (polyethylene terephthalate, PET, or polyethylene napthalate, PEN); plus 2) pre- deposited photovoltaic (PV) cells and mini-modules consisting of amorphous silicon (a-Si) and copper indium gallium diselenide (CIGS) thin-film PV technologies. We used plasma enhanced chemical vapor deposition (PECVD) process with dilute silane, nitrogen, and nitrous oxide/oxygen gas mixtures in a low-power (< or = 10 milliW per cm2) RF discharge at ~ 0.2 Torr pressure, and low substrate temperatures < or = 100(degrees)C, over deposition areas ~ 1000 cm2. Barrier properties of the resulting PV cells and coated-glass packaging structures were studied with subsequent stressing in damp-heat exposure at 85(degrees)C/85% RH. Preliminary results on PV cells and coated glass indicate the palpable benefits of the barriers in mitigating moisture intrusion and degradation of the underlying structures using SiOxNy coatings with thicknesses in the range of 100-200 nm.
del Cueto, J. A.; Glick, S. H.; Terwilliger, K. M.; Jorgensen, G. J.; Pankow, J. W.; Keyes, B. M.; Gedvilas, L. M.; Pern, F. J.
Superhydrophobic Thin Film Symposium Superhydrophobic Thin Film Symposium Sep 05 2012 12:00 AM - 05:00 PM Hosted by Oak Ridge Laboratory's Partnerships Directorate and focusing on the recent LDRD Launch project work completed by Dr. Tolga Aytug and Dr. John T. Simpson (ORNL research PI's). Oak Ridge, TN Oak Ridge National Laboratory CONTACT : Email: Cassie Lopez Phone:(865) 576-9294 Add to Calendar SHARE Hosted by Oak Ridge Laboratory's Partnerships Directorate and focusing on the recent LDRD Launch project work completed by Dr. Tolga Aytug and Dr. John T. Simpson (ORNL research PI's). Purpose To share the ORNL Superhydrophonbic Thin Film technology to prospective commercial partners. Date and Time The conference will be held on the morning of Wednesday September 5th at Oak Ridge National Laboratory (ORNL) by Partnerships and Technology
Method for synthesizing thin film electrodes
A method for making a thin-film electrode, either an anode or a cathode, by preparing a precursor solution using an alkoxide reactant, depositing multiple thin film layers with each layer approximately 500 1000 .ANG. in thickness, and heating the layers to above 600.degree. C. to achieve a material with electrochemical properties suitable for use in a thin film battery. The preparation of the anode precursor solution uses Sn(OCH.sub.2C(CH.sub.3).sub.3).sub.2 dissolved in a solvent in the presence of HO.sub.2CCH.sub.3 and the cathode precursor solution is formed by dissolving a mixture of (Li(OCH.sub.2C(CH.sub.3).sub.3)).sub.8 and Co(O.sub.2CCH.sub.3).H.sub.2O in at least one polar solvent.
Boyle, Timothy J. (Albuquerque, NM)
Thin-film rechargeable lithium batteries
Small thin-film rechargeable cells have been fabricated with a lithium phosphorus oxyniuide electrolyte, Li metal anode, and Li{sub 1-x}Mn{sub 2}O{sub 4} as the cathode film. The cathode films were fabricated by several different techniques resulting in both crystalline and amorphous films. These were compared by observing the cell discharge behavior. Estimates have been made for the scale-up of such a thin-film battery to meet the specifications for the electric vehicle application. The specific energy, energy density, and cycle life are expected to meet the USABC mid-term criteria. However, the areas of the thin-films needed to fabricate such a cell are very large. The required areas could be greatly reduced by operating the battery at temperatures near 100{degrees}C or by enhancing the lithium ion transport rate in the cathode material.
Dudney, N.J.; Bates, J.B.; Lubben, D.
Mesoscale morphologies in polymer thin films.
In the midst of an exciting era of polymer nanoscience, where the development of materials and understanding of properties at the nanoscale remain a major R&D endeavor, there are several exciting phenomena that have been reported at the mesoscale (approximately an order of magnitude larger than the nanoscale). In this review article, we focus on mesoscale morphologies in polymer thin films from the viewpoint of origination of structure formation, structure development and the interaction forces that govern these morphologies. Mesoscale morphologies, including dendrites, holes, spherulites, fractals and honeycomb structures have been observed in thin films of homopolymer, copolymer, blends and composites. Following a largely phenomenological level of description, we review the kinetic and thermodynamic aspects of mesostructure formation outlining some of the key mechanisms at play. We also discuss various strategies to direct, limit, or inhibit the appearance of mesostructures in polymer thin films as well as an outlook toward potential areas of growth in this field of research.
Ramanathan, M.; Darling, S. B. (Center for Nanoscale Materials)
Solution of thin film magnetization problems in type-II superconductivity
Keywords: critical current, numerical solution, superconductivity, thin film, variational inequality
Leonid Prigozhin
Thin-film rechargeable lithium batteries using ceramic electrolyte and cathode materials have been fabricated by physical deposition techniques. The lithium phosphorous oxynitride electrolyte has exceptional electrochemical stability and a good lithium conductivity. The lithium insertion reaction of several different intercalation materials, amorphous V{sub 2}O{sub 5}, amorphous LiMn{sub 2}O{sub 4}, and crystalline LiMn{sub 2}O{sub 4} films, have been investigated using the completed cathode/electrolyte/lithium thin-film battery.
Dudney, N.J.; Bates, J.B.; Lubben, D. [Oak Ridge National Lab., TN (United States). Solid State Div.
Thin-film Rechargeable Lithium Batteries
DOE R&D Accomplishments (OSTI)
Thin film rechargeable lithium batteries using ceramic electrolyte and cathode materials have been fabricated by physical deposition techniques. The lithium phosphorous oxynitride electrolyte has exceptional electrochemical stability and a good lithium conductivity. The lithium insertion reaction of several different intercalation materials, amorphous V{sub 2}O{sub 5}, amorphous LiMn{sub 2}O{sub 4}, and crystalline LiMn{sub 2}O{sub 4} films, have been investigated using the completed cathode/electrolyte/lithium thin film battery.
Dudney, N. J.; Bates, J. B.; Lubben, D.
SAW determination of surface area of thin films
N.sub.2 adsorption isotherms are measured from thin films on SAW devices. The isotherms may be used to determine the surface area and pore size distribution of thin films.
Frye, Gregory C. (Albuquerque, NM); Martin, Stephen J. (Albuquerque, NM); Ricco, Antonio J. (Albuquerque, NM)
Photovoltaic material and device measurements workshop: focus on polycrystalline thin film cells
The general purpose of the workshop was to accelerate the development of thin film solar cells by improving the versatility and reliability of material and device measurement techniques. Papers were presented under the following sessions: structural/chemical session; optical/electro-optical session; charge transport session; and poster session. Each paper was processed for EDB.
Data mining and statistical techniques for characterizing the performance of thin-film photovoltaic modules
A method for characterizing the performance ratio of thin-film photovoltaic modules based on the use of data mining and statistical techniques is developed. In general, this parameter changes when modules are working in outdoor conditions depending on ... Keywords: Data mining, Performance ratio, Photovoltaic modules, Solar spectral distribution, Statistical models
Rafael Moreno S�ez, Mariano Sidrach-De-Cardona, Llanos Mora-L�pez
POTENTIAL APPLI ATIONS Improved performance of thin For more information or Solar & renewable energy Photovoltaic Thin-film solar cells
Using in Situ Thin Film Stress Measurements to Understand ...
Symposium, Nanostructured Materials for Lithium Ion Batteries and for Supercapacitors. Presentation Title, Using in Situ Thin Film Stress Measurements to�...
Synthesis and Characterization of Plasma Polymerized Thin Films ...
Presentation Title, Synthesis and Characterization of Plasma Polymerized Thin Films Deposited from Benzene and Hexamethyldisiloxane Using (PECVD)�...
Fracture and Delamination in Thin Film Si Electrodes
Symposium, Nanostructured Materials for Lithium Ion Batteries and for Supercapacitors. Presentation Title, Fracture and Delamination in Thin Film Si Electrodes.
Magnetic properties of TM/RE bilayer thin films
... Magnetic properties of TM/RE bilayer thin films. I. Zoto University of Alabama. The magnetic recording technology badly ...
Development of high, stable-efficiency triple-junction a-Si alloy solar cells. Final technical report
This report summarizes Energy Conversion Devices, Inc.`s (ECD) research under this program. ECD researchers explored the deposition of a-Si at high rates using very-high-frequency plasma MHz, and compared these VHF i-layers with radio-frequency (RF) plasma-deposited i-layers. ECD conducted comprehensive research to develop a {mu}c-Si p{sup +} layer using VHF deposition process with the objectives of establishing a wider process window for the deposition of high-quality p{sup +} materials and further enhancing their performance of a-Si solar cells by improving its p-layers. ECD optimized the deposition of the intrinsic a-Si layer and the boron-doped {mu}c-Si p{sup +} layer to improve the V{sub oc}. Researchers deposited wide-bandgap a-Si films using high hydrogen dilution; investigated the deposition of the ZnO layer (for use in back-reflector) using a sputter deposition process involving metal Zn targets; and obtained a baseline fabrication for single-junction a-Si n-i-p devices with 10.6% initial efficiency and a baseline fabrication for triple-junction a-Si devices with 11.2% initial efficiency. ECD researchers also optimized the deposition parameters for a-SiGe with high Ge content; designed a novel structure for the p-n tunnel junction (recombination layer) in a multiple-junction solar cell; and demonstrated, in n-i-p solar cells, the improved stability of a-Si:H:F materials when deposited using a new fluorine precursor. Researchers investigated the use of c-Si(n{sup +})/a-Si alloy/Pd Schottky barrier device as a tool for the effective evaluation of photovoltaic performance on a-Si alloy materials. Through alterations in the deposition conditions and system hardware, researchers improved their understanding for the deposition of uniform and high-quality a-Si and a-SiGe films over large areas. ECD researchers also performed extensive research to optimize the deposition process of the newly constructed 5-MW back-reflector deposition machine.
Deng, X.; Jones, S.J.; Liu, T.; Izu, M. [Energy Conversion Devices, Inc., Troy, MI (United States)
NANO-INDENTATION OF COPPER THIN FILMS ON SILICON SUBSTRATES S. Suresh1 , T.-G. Nieh2 and B.W. Choi2: Mechanical properties; Nano-indentation; Thin films; Copper; Dislocations Introduction Indentation methods films on substrates (e.g., [2,3]) using instrumented indentation. Nano-indentation studies of thin films
Suresh, Subra
High-Throughput Thin Film Approach for Screening of Temperature-Pressure-Composition Phase Space
Many solar energy technologies, for example CIGS and CdTe photovoltaics, utilize materials in thin film form. The equilibrium phase diagrams for these and other more novel solar energy materials are not known or are irrelevant because of the non-equilibrium character of the thin film growth processes. We demonstrate a high-throughput thin film approach for screening of temperature-pressure-composition phase diagrams and phase spaces. The examples in focus are novel solar absorbers Cu-N, Cu-O and p-type transparent conductors in the Cr2O3-MnO system. The composition axis of the Cr2O3-MnO phase diagram was screened using a composition spread method. The temperature axis of the Mn-O phase diagram was screened using a temperature spread method. The pressure axes of the Cu-N and Cu-O phase diagrams were screened using rate spread method with the aid of non-equilibrium growth phenomena. Overall these three methods constitute an approach to high-throughput screening of inorganic thin film phase diagrams. This research is supported by U.S. Department of Energy as a part of two NextGen Sunshot projects and an Energy Frontier Research Center.
Zakutayev, A.; Subramaniyan, A.; Caskey, C. M.; Ndione, P. F.; Richards, R. M.; O'Hayre, R.; Ginley, D. S.
Deposition of a-SiC:H, a-SiO{sub 2} and tetrahedral-C with programmable in-situ etching. Final performance report, March 1, 1988--November 30, 1991
This research program was originally defined to investigate the deposition of semiconductor and dielectric thin films using a low pressure remote plasma chemical vapor deposition system incorporating a process for etching the films. This etching was to be performed in a periodic fashion during the deposition process to remove defect regions in the film being deposited. The goal was to remove voids and other defects which are characteristic of low temperature deposition processes. While the original research proposal suggested that the studies include the amorphous alloys (Si/C):H and (Si/Ge):H, subsequent funding reductions limited the work to the deposition of an amorphous silicon alloy material (a-Si:H). Intrinsic and doped forms of these materials have applications in the fabrication of single and multi-junction thin film solar cells.
Collis, W.J.
Photovoltaic Polycrystalline Thin-Film Cell Basics | Department of Energy
Polycrystalline Thin-Film Cell Basics Polycrystalline Thin-Film Cell Basics Photovoltaic Polycrystalline Thin-Film Cell Basics August 20, 2013 - 2:36pm Addthis Polycrystalline thin-film cells are made of many tiny crystalline grains of semiconductor materials. The materials used in these cells have properties that are different from those of silicon. Thin-film cells have many advantages over their thick-film counterparts. For example, they use much less material. The cell's active area is usually only 1 to 10 micrometers thick, whereas thick films typically are 100 to 300 micrometers thick. Also, thin-film cells can usually be manufactured in a large-area process, which can be an automated, continuous production process. Finally, they can be deposited on flexible substrate materials. The term thin film comes from the method used to deposit the film, not from
Amorphous carbon thin films for optoelectric device application
Thin films of amorphous carbon (a-C and a-C:H) have been deposited using different carbon precursor materials such as camphor--a natural source, graphite and CH{sub 4}/H{sub 2} mixture by different deposition methods, such as ion beam sputtering, pyrolysis, pulsed laser deposition and r.f. plasma CVD. The films are subjected to various standard characterization techniques in order to tailor the required structural and opto-electrical properties for device applications. The effects of deposition parameters and annealing temperatures on the properties of carbon thin films have been investigated. Both p- and n- type of carbon films have been obtained either through controlling the deposition parameters of a particular method or by doping. Solar cells of various configurations, such as n-C/p-Si, p-C/n-Si and n-C/p-C/p-Si, have been fabricated and their photoresponse characteristics are studied. An efficiency of 1.52% has been obtained, so far, for the cell of configuration n-C/p-C/p-Si. Effects of substrate temperature on the photovoltaic properties are also outlined in brief.
Soga, T.; Jimbo, T.; Krishna, K.M.; Umeno, M.
Polycrystalline thin films FY 1992 project report
This report summarizes the activities and results of the Polycrystalline Thin Film Project during FY 1992. The purpose of the DOE/NREL PV (photovoltaic) Program is to facilitate the development of PV that can be used on a large enough scale to produce a significant amount of energy in the US and worldwide. The PV technologies under the Polycrystalline Thin Film project are among the most exciting next-generation'' options for achieving this goal. Over the last 15 years, cell-level progress has been steady, with laboratory cell efficiencies reaching levels of 15 to 16%. This progress, combined with potentially inexpensive manufacturing methods, has attracted significant commercial interest from US and international companies. The NREL/DOE program is designed to support the efforts of US companies through cost-shared subcontracts (called government/industry partnerships'') that we manage and fund and through collaborative technology development work among industry, universities, and our laboratory.
Zweibel, K. (ed.)
This report summarizes the activities and results of the Polycrystalline Thin Film Project during FY 1992. The purpose of the DOE/NREL PV (photovoltaic) Program is to facilitate the development of PV that can be used on a large enough scale to produce a significant amount of energy in the US and worldwide. The PV technologies under the Polycrystalline Thin Film project are among the most exciting ``next-generation`` options for achieving this goal. Over the last 15 years, cell-level progress has been steady, with laboratory cell efficiencies reaching levels of 15 to 16%. This progress, combined with potentially inexpensive manufacturing methods, has attracted significant commercial interest from US and international companies. The NREL/DOE program is designed to support the efforts of US companies through cost-shared subcontracts (called ``government/industry partnerships``) that we manage and fund and through collaborative technology development work among industry, universities, and our laboratory.
Zweibel, K. [ed.
Electrostatic thin film chemical and biological sensor
A chemical and biological agent sensor includes an electrostatic thin film supported by a substrate. The film includes an electrostatic charged surface to attract predetermined biological and chemical agents of interest. A charge collector associated with said electrostatic thin film collects charge associated with surface defects in the electrostatic film induced by the predetermined biological and chemical agents of interest. A preferred sensing system includes a charge based deep level transient spectroscopy system to read out charges from the film and match responses to data sets regarding the agents of interest. A method for sensing biological and chemical agents includes providing a thin sensing film having a predetermined electrostatic charge. The film is exposed to an environment suspected of containing the biological and chemical agents. Quantum surface effects on the film are measured. Biological and/or chemical agents can be detected, identified and quantified based on the measured quantum surface effects.
Prelas, Mark A. (Columbia, MO); Ghosh, Tushar K. (Columbia, MO); Tompson, Jr., Robert V. (Columbia, MO); Viswanath, Dabir (Columbia, MO); Loyalka, Sudarshan K. (Columbia, MO)
Thin film photovoltaic panel and method
A thin film photovoltaic panel includes a backcap for protecting the active components of the photovoltaic cells from adverse environmental elements. A spacing between the backcap and a top electrode layer is preferably filled with a desiccant to further reduce water vapor contamination of the environment surrounding the photovoltaic cells. The contamination of the spacing between the backcap and the cells may be further reduced by passing a selected gas through the spacing subsequent to sealing the backcap to the base of the photovoltaic panels, and once purged this spacing may be filled with an inert gas. The techniques of the present invention are preferably applied to thin film photovoltaic panels each formed from a plurality of photovoltaic cells arranged on a vitreous substrate. The stability of photovoltaic conversion efficiency remains relatively high during the life of the photovoltaic panel, and the cost of manufacturing highly efficient panels with such improved stability is significantly reduced.
Ackerman, Bruce (El Paso, TX); Albright, Scot P. (El Paso, TX); Jordan, John F. (El Paso, TX)
Polycrystalline thin film materials and devices. Annual subcontract report, 16 January 1991--15 January 1992
Baron, B.N.; Birkmire, R.W.; Phillips, J.E.; Shafarman, W.N.; Hegedus, S.S.; McCandless, B.E. [Delaware Univ., Newark, DE (United States). Inst. of Energy Conversion
Rechargeable thin-film lithium batteries
Rechargeable thin-film batteries consisting of lithium metal anodes, an amorphous inorganic electrolyte, and cathodes of lithium intercalation compounds have recently been developed. The batteries, which are typically less than 6-{mu}m thick, can be fabricated to any specified size, large or small, onto a variety of substrates including ceramics, semiconductors, and plastics. The cells that have been investigated include Li-TiS{sub 2}, Li-V{sub 2}O{sub 5}, and Li-Li{sub x}Mn{sub 2}O{sub 4}, with open circuit voltages at full charge of about 2.5, 3.6, and 4.2, respectively. The development of these batteries would not have been possible without the discovery of a new thin-film lithium electrolyte, lithium phosphorus oxynitride, that is stable in contact with metallic lithium at these potentials. Deposited by rf magnetron sputtering of Li{sub 3}PO{sub 4} in N{sub 2}, this material has a typical composition of Li{sub 2.9}PO{sub 3.3}N{sub 0.46} and a conductivity at 25{degrees}C of 2 {mu}S/cm. The maximum practical current density obtained from the thin-film cells is limited to about 100 {mu}A/cm{sup 2} due to a low diffusivity of Li{sup +} ions in the cathodes. In this work, the authors present a short review of their work on rechargeable thin-film lithium batteries.
Bates, J.B.; Gruzalski, G.R.; Dudney, N.J.; Luck, C.F.; Yu, Xiaohua
Packaging material for thin film lithium batteries
A thin film battery including components which are capable of reacting upon exposure to air and water vapor incorporates a packaging system which provides a barrier against the penetration of air and water vapor. The packaging system includes a protective sheath overlying and coating the battery components and can be comprised of an overlayer including metal, ceramic, a ceramic-metal combination, a parylene-metal combination, a parylene-ceramic combination or a parylene-metal-ceramic combination.
Bates, John B. (116 Baltimore Dr., Oak Ridge, TN 37830); Dudney, Nancy J. (11634 S. Monticello Rd., Knoxville, TN 37922); Weatherspoon, Kim A. (223 Wadsworth Pl., Oak Ridge, TN 37830)
Superconducting thin films on potassium tantalate substrates
A superconductive system for the lossless transmission of electrical current comprising a thin film of superconducting material Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x epitaxially deposited upon a KTaO.sub.3 substrate. The KTaO.sub.3 is an improved substrate over those of the prior art since the it exhibits small lattice constant mismatch and does not chemically react with the superconducting film.
Feenstra, Roeland (Oak Ridge, TN); Boatner, Lynn A. (Oak Ridge, TN)
Thin Film Solid Oxide Fuel Cells
A novel solid oxide fuel cell (SOFC) design that can be fabricated entirely using low-temperature, thin-film processing is described. Potential advantages of the cell are reduced materials costs and improved fuel-cell characteristics. The critical design feature is the use of thin (approximately equal to 50 nanometers), catalytically-active oxide layers on a < 10 micrometer thick yttria-stabilized zirconia (YSZ) supported electrolyte to minimize reaction overpotentials and ohmic losses. Doped ceria at th...
Shengrui Solar | Open Energy Information
search Name Shengrui Solar Place Hong Kong Product Hong Kong headquartered company with thin-film PV production in China. References Shengrui Solar1 LinkedIn Connections...
Investigations of CuInSe2 Thin Films and Contacts: Annual Subcontract Report, 1 January 1990 - 28 February 1991
This report describes research into electrical contacts for copper indium diselenide (CulnSe2) polycrystalline thin films used for solar cell applications. Molybdenum contacts have historically been the most promising for heterojunction solar cells. This program studied contact stability by investigating thermally induced bilayer reactions between molybdenum and copper, indium, and selenium. Because selenization is widely used to fabricate CulnSe2 thin films for photovoltaic cells, a second part of the program investigated how the morphologies, phases, and reactions of pre-selenization Cu-In structures are affected by the deposition process and heat treatments.
Nicolet, M. A.
Polycrystalline thin film materials and devices. Final subcontract report, 16 January 1990--15 January 1993
This report describes results and conclusions of the final phase (III) of a three-year research program on polycrystalline thin-film heterojunction solar cells. The research consisted of the investigation of the relationships between processing, materials properties, and device performance. This relationship was quantified by device modeling and analysis. The analysis of thin-film polycrystalline heterojunction solar cells explains how minority-carrier recombination at the metallurgical interface and at grain boundaries can be greatly reduced by the proper doping of the window and absorber layers. Additional analysis and measurements show that the present solar cells are limited by the magnitude of the diode current, which appears to be caused by recombination in the space charge region. Developing an efficient commercial-scale process for fabricating large-area polycrystalline, thin-film solar cells from a research process requires a detailed understanding of the individual steps in making the solar cell, and their relationship to device performance and reliability. The complexities involved in characterizing a process are demonstrated with results from our research program on CuInSe{sub 2}, and CdTe processes.
Birkmire, R.W.; Phillips, J.E.; Shafarman, W.N.; Hegedus, S.S.; McCandless, B.E.; Yokimcus, T.A. [Delaware Univ., Newark, DE (United States). Inst. of Energy Conversion
Fabrication Of Multilayered Thin Films Via Spin-Assembly
Fabrication Of Multilayered Thin Films Via Spin-Assembly Fabrication Of Multilayered Thin Films Via Spin-Assembly Fabrication Of Multilayered Thin Films Via Spin-Assembly A process of forming multilayer thin film heterostructures. Available for thumbnail of Feynman Center (505) 665-9090 Email Fabrication Of Multilayered Thin Films Via Spin-Assembly A process of forming multilayer thin film heterostructures is disclosed and includes applying a solution including a first water-soluble polymer from the group of polyanionic species, polycationic species and uncharged polymer species onto a substrate to form a first coating layer on the substrate, drying the first coating layer on the substrate, applying a solution including a second water-soluble polymer from the group of polyanionic species, polycationic species and uncharged polymer species
Interim qualification tests and procedures for terrestrial photovoltaic thin-film flat-plate modules
This document provides recommended procedures and specifications for qualification tests that are structured to evaluate terrestrial thin-film flat-plate photovoltaic nonconcentrating modules intended for power generation applications. The qualification tests provided in this document are designed to evaluate flat-plate thin-film photovoltaic (PV) module design performance and susceptibility to known failure mechanisms. Emphasis is placed on testing and evaluating module performance characteristics and design features that will affect possible degradation of module performance and physical properties resulting from solar exposure, environmental weathering, mechanical loading, corrosion, and module shadowing. Because of limited thin-film module field operation experience and the evolutionary nature of new thin-film module material technologies and designs, these tests should not be considered definitive or complete, nor do they provide a basis to predict 30-year field life. Current understanding of failure and degradation mechanisms and the relationship between accelerated tests and field reliability is not sufficient to allow accurate estimation of life-expectancy, nor are the cycling tests given in this document considered to be equivalent to a full 30-year field exposure. However, the test and evaluation procedures given in this document provide a common approach for conducting qualification tests. Acceptable results from these tests should provide reasonable assurance that the modules that pass these tests will perform reliably in the field but for an unspecified period of time. 8 refs., 6 figs.
DeBlasio, R.; Mrig, L.; Waddington, D.
High-Efficiency Amorphous Silicon Alloy Based Solar Cells and Modules; Final Technical Progress Report, 30 May 2002--31 May 2005
The principal objective of this R&D program is to expand, enhance, and accelerate knowledge and capabilities for development of high-efficiency hydrogenated amorphous silicon (a-Si:H) and amorphous silicon-germanium alloy (a-SiGe:H) related thin-film multijunction solar cells and modules with low manufacturing cost and high reliability. Our strategy has been to use the spectrum-splitting triple-junction structure, a-Si:H/a-SiGe:H/a-SiGe:H, to improve solar cell and module efficiency, stability, and throughput of production. The methodology used to achieve the objectives included: (1) explore the highest stable efficiency using the triple-junction structure deposited using RF glow discharge at a low rate, (2) fabricate the devices at a high deposition rate for high throughput and low cost, and (3) develop an optimized recipe using the R&D batch large-area reactor to help the design and optimization of the roll-to-roll production machines. For short-term goals, we have worked on the improvement of a-Si:H and a-SiGe:H alloy solar cells. a-Si:H and a-SiGe:H are the foundation of current a-Si:H based thin-film photovoltaic technology. Any improvement in cell efficiency, throughput, and cost reduction will immediately improve operation efficiency of our manufacturing plant, allowing us to further expand our production capacity.
Guha, S.; Yang, J.
Single-Crystalline Thin Film Used in Photovoltaics
Single-crystalline thin films are made from gallium arsenide (GaAs), a compound semiconductor that is a mixture of gallium and arsenic.
Evaluation of Thin-film Interfacial Properties Using Indentation Test
A thin film's reliable question is depend on interfacial characterization, so evaluating interfacial characterization is the most important things in this test. So far�...
Ferroelectric Thin Film Capacitors to Enable a Miniaturized Smart L ...
The effects ultra-violet (UV)-assisted processing and compositional grading of BST capacitor thin films will be presented and the material property trade-offs for �...
Electron Beam Evaporator Systems for Thin Film Deposition
The Thin Film and Nanostructure Processing Group has two high-vacuum, electron beam evaporator systems for fabrication of single and multilayer ...
Layer-by-Layer Assembled Thin Films for Battery Electrolytes
Presentation Title, Layer-by-Layer Assembled Thin Films for Battery Electrolytes ... Abstract Scope, Exponential layer-by-layer (eLBL) assembled battery�...
Tungsten-doped thin film materials - Energy Innovation Portal
A dielectric thin film material for high frequency use, including use as a capacitor, and having a low dielectric loss factor is provided, the film comprising a ...
Thin-Film Ferroelectric Materials for Decoupling and Tunable ...
Symposium, ACerS Richard M. Fulrath Award Symposium. Presentation Title, Thin-Film Ferroelectric Materials for Decoupling and Tunable Capacitors. Author( s)�...
Development of Polyimide/SMA Thin-Film Actuator
Symposium, Symposium I: Biomaterials, Smart Materials and Structures. Presentation Title, Development of Polyimide/SMA Thin-Film Actuator. Author(s), Akira�...
Integrated Technology of Decoupling BST Thin Film Capacitors
Jun 16, 2007 ... The integration technology of decoupling capacitors, which contain multi-layered Cu wiring and Barium Strontium Titanate (BST) thin film�...
How Thin Film Processing Can Contribute to Understanding the ...
Presentation Title, How Thin Film Processing Can Contribute to Understanding the Materials Science of the MAX Phases. Author(s), Per Eklund, Ulf Jansson,�...
Fabrication of Solid Oxide Fuel Cells via Thin Film Techniques
We decided to use thin film techniques to solve this problem. Among various methods of lowering the operation temperature for SOFCs, adopting bi-layer�...
Lessons Learned in Sputtering TiNi Thin Film
Experimental results have been published in journals and conference proceedings, but as yet TiNi thin film is not commercially available. The author and�...
AMORPHOUS THIN FILMS CONSISTING OF TERNARY MgZnCa ...
Jul 20, 2012 ... AMORPHOUS THIN FILMS CONSISTING OF TERNARY MgZnCa-ALLOYS by K. Schl�ter, C. Zamponi, U. Sch�rmann, N. Hort, L. Kienle, K.U.�...
Chemistry Chemical Analysis Thin-Films Information at NIST
... Method Can Affect the Use of Block Copolymer Thin Films (10/18 ... NIST Scientists Address 'Wrinkles' in Transparent Film Development (10/02/2012). ...
NIST Testing Method Quickly Tells Whether Thin Films Are ...
... and emerging technology areas that rely on thin-film advances for ... For films less than 1 micrometer thick, mechanical-property measurements made ...
Interface Adhesion and Coating Integrity of the Thin Film Au ...
Current scientific emphasis is on process development and optimization of thin film Au-interconnect metallization for the Bi2Te3-based TE module used for the�...
Development of Thin-Film Materials Technology for Energy Applications...
Development of Thin-Film Materials Technology for Energy Applications: High Temperature Superconductors, etc. Speaker(s): Ronald Reade Date: January 15, 2002 - 12:00pm Location:...
Bi-based Piezoelectric Thin Films via Chemical Solution Deposition
BNT-BKT-BMgT thin films showed very promising piezoelectric response with ... Chemical Quantification of Oxide Interfaces Using Energy-dispersive X-ray�...
Thermoelectric effect in very thin film Pt/Au thermocouples
thin films, the electrical resistivity ratio ? F /? B is BStudies of the electrical resistivity of metallic films [23,calculate the electrical resistivity and the thermoelectric
Salvadori, M.C.; Vaz, A.R.; Teixeira, F.S.; Cattani, M.; Brown, I.G.
Thin film techniques for solid oxide fuel cells
Thin film techniques for solid oxide fuel cells V.E.J. van Dieten and J. Schoonman Laboratory ... ticles stay in the hot temperature region can be ...
Diffraction: Enhanced Light Absorption of Solar Cells and ...
Solar and Renewable Energy Photovoltaic Thin-film Solar Cells Space Solar Cells Polarization-Dependent Photodetectors BENEFITS Improved performance of
SSC HHV Solar Technologies JV | Open Energy Information
JV Jump to: navigation, search Name SSC & HHV Solar Technologies JV Place Ontario, Canada Sector Solar Product Canada-based thin film solar panel manufacturing facility....
Thin film photovoltaic device with multilayer substrate
A thin film photovoltaic device which utilizes at least one compound semiconductor layer chosen from Groups IIB and VA of the Periodic Table is formed on a multilayer substrate The substrate includes a lowermost support layer on which all of the other layers of the device are formed. Additionally, an uppermost carbide or silicon layer is adjacent to the semiconductor layer. Below the carbide or silicon layer is a metal layer of high conductivity and expansion coefficient equal to or slightly greater than that of the semiconductor layer.
Catalano, Anthony W. (Rushland, PA); Bhushan, Manjul (Wilmington, DE)
Articles including thin film monolayers and multilayers
This invention pertains to thin film assemblies or devices useful as sensors, nonlinear optical materials, and trace material scavengers. It claims a base substrate having an oxide surface layer, and a multidentate ligand, capable of binding a metal ion, attached to the oxide surface layer of the base substrate. A metal species may be provided attached to the ligand, and a multifunctional organic ligand may be provided attached to the metal species. A second metal species may be provided attached to the multifunctional ligand.
Li, DeQuan; Swanson, B.I.
Well-Passivated a-Si:H Back Contacts for Double-Heterojunction Silicon Solar Cells: Preprint
We have developed hydrogenated amorphous silicon (a Si:H) back contacts to both p- and n-type silicon wafers, and employed them in double-heterojunction solar cells. These contacts are deposited entirely at low temperature (<250 C) and replace the standard diffused or alloyed back-surface-field contacts used in single-heterojunction (front-emitter only) cells. High-quality back contacts require excellent surface passivation, indicated by a low surface recombination velocity of minority-carriers (S) or a high open-circuit voltage (Voc). The back contact must also provide good conduction for majority carriers to the external circuit, as indicated by a high light I-V fill factor. We use hot-wire chemical vapor deposition (HWCVD) to grow a-Si:H layers for both the front emitters and back contacts. Our improved a-Si:H back contacts contribute to our recent achievement of a confirmed 18.2% efficiency in double-heterojunction silicon solar cells on p type textured silicon wafers.
Page, M. R.; Iwaniczko, E.; Xu, Y.; Wang, Q.; Yan, Y.; Roybal, L.; Branz, H. M.; Wang, T. H.
Apparatus for laser assisted thin film deposition
A pulsed laser deposition apparatus uses fiber optics to deliver visible output beams. One or more optical fibers are coupled to one or more laser sources, and delivers visible output beams to a single chamber, to multiple targets in the chamber or to multiple chambers. The laser can run uninterrupted if one of the deposition chambers ceases to operate because other chambers can continue their laser deposition processes. The laser source can be positioned at a remote location relative to the deposition chamber. The use of fiber optics permits multi-plexing. A pulsed visible laser beam is directed at a generally non-perpendicular angle upon the target in the chamber, generating a plume of ions and energetic neutral species. A portion of the plume is deposited on a substrate as a thin film. A pulsed visible output beam with a high pulse repetition frequency is used. The high pulse repetition frequency is greater than 500 Hz, and more preferably, greater than about 1000 Hz. Diamond-like-carbon (DLC) is one of the thin films produced using the apparatus.
Warner, Bruce E. (Pleasanton, CA); McLean, II, William (Oakland, CA)
Rechargeable thin-films batteries with lithium metal anodes, an amorphous inorganic electrolyte, and cathodes of lithium intercalation compounds have been fabricated and characterized. The cathodes include TiS{sub 2}, the {omega} phase of V{sub 2}O{sub 5}, and the cubic spinel Li{sub x}Mn{sub 2}O{sub 4} with open circuit voltages at full charge of about 2.5 V, 3.7 V, and 4.2 V, respectively. The development of these robust cells, which can be cycled thousands of times, was possible because of the stability of the amorphous lithium electrolyte, lithium phosphorus oxynitride. This material has a typical composition of Li{sub 2.9}PO{sub 3.3}N{sub 0.46} and a conductivity at 25 C of 2 {mu}S/cm. Thin-film cells have been cycled at 100% depth of discharge using current densities of 2 to 100 {mu}A/cm{sup 2}. The polarization resistance of the cells is due to the slow insertion rate of Li{sup +} ions into the cathode. Chemical diffusion coefficients for Li{sup +} ions in the three types of cathodes have been estimated from the analysis of ac impedance measurements.
Bates, J.B.; Gruzalski, G.R.; Dudney, N.J.; Luck, C.F.; Yu, X.
Rechargeable thin-film batteries consisting of lithium metal anodes, an amorphous inorganic electrolyte, and cathodes of lithium intercalation compounds have been fabricated and characterized. These include Li-TiS{sub 2}, Li-V{sub 2}O{sub 5}, and Li-Li{sub x}Mn{sub 2}O{sub 4} cells with open circuit voltages at full charge of about 2.5 V, 3.7 V, and 4.2 V, respectively. The realization of these robust cells, which can be cycled thousands of times, was possible because of the stability of the amorphous lithium electrolyte, lithium phosphorus oxynitride. This material has a typical composition of Li{sub 2.9}PO{sub 3.3}N{sub 0.46}and a conductivity at 25 C of 2 {mu}S/cm. The thin-film cells have been cycled at 100% depth of discharge using current densities of 5 to 100 {mu}A/cm{sup 2}. Over most of the charge-discharge range, the internal resistance appears to be dominated by the cathode, and the major source of the resistance is the diffusion of Li{sup +} ions from the electrolyte into the cathode. Chemical diffusion coefficients were determined from ac impedance measurements.
Spin hall effect in paramagnetic thin films
Spintronics, an abbreviation of spin based electronics and also known as magneto electronics, has attracted a lot of interest in recent years. It aims to explore the role of electrons� spins in building next generation electric devices. Using electrons� spins rather than electrons� charges may allow faster, lower energy cost devices. Spin Hall Effect is an important subfield of spintronics. It studies spin current, spin transport, and spin accumulation in paramagnetic systems. It can further understanding of quantum physics, device physics, and may also provide insights for spin injection, spin detection and spin manipulation in the design of the next generation spintronics devices. In this experimental work, two sets of experiments were prepared to detect the Spin Hall Effect in metallic systems. The first set of experiments aims to extract Spin Hall Effect from Double Hall Effect in micrometer size metal thin film patterns. Our experiments proved that the Spin Hall Effect signal was much smaller than the theoretically calculated value due to higher electrical resistivity in evaporated thin films. The second set of experiments employs a multi-step process. It combines micro fabrication and electrochemical method to fabricate a perpendicular ferromagnet rod as a spin injector. Process description and various techniques to improve the measurement sensitivity are presented. Measurement results in aluminum, gold and copper are presented in Chapters III, IV and V. Some new experiments are suggested in Chapters V and VI.
Xu, Huachun
Rechargeable thin films batteries with lithium metal anodes, an amorphous inorganic electrolyte, and cathodes of lithium intercalation compounds have been fabricated and characterized. The cathodes include TiS{sub 2}, the {omega} phase of V{sub 2}O{sub 5}, and the cubic spinel Li{sub x}Mn{sub 2}O{sub 4} with open circuit voltages at full charge of about 2.5 V, 3.7 V, and 4.2 V, respectively. The development of these robust cells, which can be cycled thousands of times, was possible because of the stability of the amorphous lithium electrolyte, lithium phosphorus oxynitride. This material has a typical composition of Li{sub 2.9}PO{sub 3.3}N{sub 0.46} and a conductivity at 25 C of 2 {mu}S/cm. Thin film cells have been cycled at 100% depth of discharge using current densities of 2 to 100 {mu}A/cm{sup 2}. The polarization resistance of the cells is due to the slow insertion rate of Li{sup +} ions into the cathode. Chemical diffusion coefficients for Li{sup +} ions in the three types of cathodes have been estimated from the analysis of ac impedance measurements.
Bates, J. B.; Gruzalski, G. R.; Dudney, N. J.; Luck, C. F.; Yu, X.
Active superconducting devices formed of thin films
Active superconducting devices are formed of thin films of superconductor which include a main conduction channel which has an active weak link region. The weak link region is composed of an array of links of thin film superconductor spaced from one another by voids and selected in size and thickness such that magnetic flux can propagate across the weak link region when it is superconducting. Magnetic flux applied to the weak link region will propagate across the array of links causing localized loss of superconductivity in the links and changing the effective resistance across the links. The magnetic flux can be applied from a control line formed of a superconducting film deposited coplanar with the main conduction channel and weak link region on a substrate. The devices can be formed of any type to superconductor but are particularly well suited to the high temperature superconductors since the devices can be entirely formed from coplanar films with no overlying regions. The devices can be utilized for a variety of electrical components, including switching circuits, amplifiers, oscillators and modulators, and are well suited to microwave frequency applications.
Martens, Jon S. (Madison, WI); Beyer, James B. (Madison, WI); Nordman, James E. (Madison, WI); Hohenwarter, Gert K. G. (Madison, WI)
Available Technologies: Thinner Film Silicon Solar Cells
Berkeley Lab scientists have designed a new approach to create highly efficient thin film silicon solar cells. This technology promises to lower solar cell material ...
Development of high stable-efficiency, triple-junction a-Si alloy solar cells. Annual subcontract report, July 18, 1994--July 17, 1995
This report describes work performed by Energy Conversion Devices, Inc. (ECD) under a 3-year, cost-shared amorphous silicon (a-Si) research program to develop advanced technologies and to demonstrate stable 14%-efficient, triple-junction a-Si alloy solar cells. The technologies developed under the program will then be incorporated into ECD`s continuous roll-to-roll deposition process to further enhance ECD`s photovoltaic manufacturing technology. In ECD`s solar cell design, triple-junction a-Si alloy solar cells are deposited onto stainless-steel substrates coated with Ag/ZnO back-reflector layers. This type of cell design enabled ECD to use a continuous roll- to-roll deposition process to manufacture a-Si PV materials in high volume at low cost. Using this cell design, ECD previously achieved 13.7% initial solar cell efficiency using the following features: (1) a triple-junction, two-band-gap, spectrum-splitting solar cell design; (2) a microcrystalline silicon p-layer; (3) a band-gap-profiled a- SiGe alloy as the bottom cell i-layer; (4) a high-performance AgZnO back-reflector; and (5) a high-performance tunnel junction between component cells. ECD also applied the technology into its 2-MW/yr a- Si production line and achieved the manufacturing of 4-ft{sup 2} PV modules with 8% stable efficiency. During this program, ECD is also further advancing its existing PV technology toward the goal of 14% stable solar cells by performing the following four tasks: (1) improving the stability of the intrinsic a-Si alloy materials; (2) improving the quality of low-band-gap a-SiGe alloy; (3) improving p{sup +} window layers, and (4) developing high stable-efficiency triple-junction a-Si alloy solar cells.
Deng, X. [Energy Conversion Devices, Inc., Troy, MI (United States)
Amorphous hafnium-indium-zinc oxide semiconductor thin film transistors
We reported on the performance and electrical properties of co-sputtering-processed amorphous hafnium-indium-zinc oxide (?-HfIZO) thin film transistors (TFTs). Co-sputtering-processed ?-HfIZO thin films have shown an amorphous phase in nature. ...
Sheng-Po Chang; San-Syong Shih
Long-laser-pulse method of producing thin films
The invention described herein arose in the course of, or under, Contract No. DE-C03-76SF0098 between the United States Department of Energy and the University of California. This invention relates in general to techniques for producing thin films, and in particular to a method of using pulsed laser to deposit high temperature supercoducting thin films. 5 figs.
Balooch, M.; Olander, D.R.; Russo, R.E.
Organic thin film transistors with double insulator layers
We have investigated a double-layer structured gate dielectric for the organic thin films transistor (OTFT) with the purpose of improving the performance of the SiO"2 gate insulator. A 50nm PMMA layer was coated on top of the SiO"2 gate insulator as ... Keywords: Mobility, On/off ratio, Organic thin film transistor, PMMA
X. Liu; Y. Bai; L. Chen; F. X. Wei; X. B. Zhang; X. Y. Jiang; Zh. L. Zhang
Thermal Sensor Arrays for The Combinatorial Analysis of Thin Films
Thermal Sensor Arrays for The Combinatorial Analysis of Thin Films A dissertation presented Advisor Author Joost J. Vlassak Patrick J. McCluskey Thermal Sensor Arrays for The Combinatorial Analysis analysis of the thermophysical properties of thin films. The continuous growth of integrated circuits
A Hyper-Elastic Thin Film Nitinol Flow Diverter for Brain Aneurysms
The thin film Nitinol is sputter deposited with transformation temperatures at or near body temperature (37C). The thin film Nitinol is micromachined using a lift off�...
Ultrafast thin-film laser-induced breakdown spectroscopy of doped...
Ultrafast thin-film laser-induced breakdown spectroscopy of doped oxides Title Ultrafast thin-film laser-induced breakdown spectroscopy of doped oxides Publication Type Journal...
Development of high, stable-efficiency triple-junction a-Si alloy solar cells. Annual technical progress report, October 1995--October 1996
The overall objective of this amorphous silicon research program is to develop high efficiency a-Si solar cells and to develop and improve processes for large area deposition of a-Si solar cells and modules. The knowledge obtained and technologies demonstrated in this program will be incorporated into ECD`s continuous roll-to-roll deposition process to further enhance its photovoltaic manufacturing technology.
Deng, X.; Izu, M.; Jones, S.J.; Kopf, R. [Energy Conversion Devices, Troy, MI (United States)] [and others
CAT-CVD process and its application to preparation of Si-based thin films
This is to review the present understanding on Cat-CVD (catalytic chemical vapor deposition) or hot wire CVD. Firstly, the deposition mechanism in Cat-CVD process is briefly mentioned along with key issues such as the effect of heat radiation and a method to avoid contamination from the catalyzer. Secondly, the properties of Cat-CVD Si-based thin films such as amorphous silicon (a-Si), polycrystalline silicon (poly-Si) and silicon nitride (SiN{sub x}) films are demonstrated, and finally, the feasibility of such films for industrial application is discussed.
Matsumura, Hideki; Masuda, Atsushi; Izumi, Akira
Dual-chamber plasma deposition of A-Si:H solar cells at high rates using disilane
The use of a separated chamber deposition system for the fabrication of a-Si:H solar cells from disilane at high deposition rates results in a substantial improvement in short circuit current compared to that obtained from a single-chamber system. The spectral responses of cells fabricated in the dual-chamber mode are compared to those made in the single-chamber mode. The results are interpreted by assuming that the rate of removal of boron contaminants from the chamber is independent of deposition rate.
Rajeswaran, G.; Vanier, P.E.; Corderman, R.R.; Kampas, F.J.
Thin-film cadmium telluride photovoltaics: ES and H issues, solutions, and perspectives
Photovoltaics (PV) is a growing business worldwide, with new technologies evolving towards potentially large-volume production. PV use produces no emissions, thus offsetting many potential environmental problems. However, the new PV technologies also bring unfamiliar environment, safety, and health (ES and H) challenges that require innovative solutions. This is a summary of the issues, solutions, and perspectives associated with the use of cadmium in one of the new and important PV technologies: thin-film, cadmium telluride (CdTe) PV, which is being developed and commercialized by several companies including Solar Cells Inc. (Toledo, Ohio), BP Solar (Fairfield, California), and Matsushita (Japan). The principal ES and H issue for thin-film cadmium telluride PV is the potential introduction of cadmium--a toxic heavy metal--into the air or water. The amount of cadmium in thin-film PV, however, is quite small--one nickel cadmium flashlight battery has about as much cadmium (7 g) as a square meter of PV module using current technology--and a typical cordless power tool will have 5--10 batteries. CdTe modules are also very well sealed, limiting the chance of release. Nonetheless, minimizing the amount of cadmium in cadmium telluride modules and preventing the introduction of that cadmium into the environment is a top priority for National Renewable Energy Laboratory researchers and cadmium telluride PV manufacturers.
Zweibel, K. [National Renewable Energy Lab., Golden, CO (US); Moskowitz, P.; Fthenakis, V. [Brookhaven National Lab., Upton, NY (US)
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)
Characterization of lithium phosphorous oxynitride thin films
Electrical and electrochemical properties of an amorphous thin-film lithium electrolyte, lithium phosphorous oxynitride (Lipon), have been studied with emphasis on the stability window vs Li metal and the behavior of the Li/Lipon interface. Ion conductivity of Lipon exhibits Arrhenius behavior at {minus}26 to +140 C, with a conductivity of 1.7 {times} 10{sup {minus}6}S/cm at 25 C and an activity energy of 0.50 {plus_minus} 0.01 eV. A stability window of 5.5 V was observed with respect to a Li{sup +}/Li reference, and no detectable reaction or degradation was evident at the Li/Lipon interface upon lithium cycling.
Yu, Xiaohua; Bates, J.B.; Jellison, G.E. Jr.
Thin Film Femtosecond Laser Damage Competition
In order to determine the current status of thin film laser resistance within the private, academic, and government sectors, a damage competition was started at the 2008 Boulder Damage Symposium. This damage competition allows a direct comparison of the current state of the art of high laser resistance coatings since they are tested using the same damage test setup and the same protocol. In 2009 a high reflector coating was selected at a wavelength of 786 nm at normal incidence at a pulse length of 180 femtoseconds. A double blind test assured sample and submitter anonymity so only a summary of the results are presented here. In addition to the laser resistance results, details of deposition processes, coating materials and layer count, and spectral results will also be shared.
Stolz, C J; Ristau, D; Turowski, M; Blaschke, H
Rechargeable thin-film electrochemical generator
An improved electrochemical generator is disclosed. The electrochemical generator includes a thin-film electrochemical cell which is maintained in a state of compression through use of an internal or an external pressure apparatus. A thermal conductor, which is connected to at least one of the positive or negative contacts of the cell, conducts current into and out of the cell and also conducts thermal energy between the cell and thermally conductive, electrically resistive material disposed on a vessel wall adjacent the conductor. The thermally conductive, electrically resistive material may include an anodized coating or a thin sheet of a plastic, mineral-based material or conductive polymer material. The thermal conductor is fabricated to include a resilient portion which expands and contracts to maintain mechanical contact between the cell and the thermally conductive material in the presence of relative movement between the cell and the wall structure. The electrochemical generator may be disposed in a hermetically sealed housing.
Rouillard, Roger (Beloeil, CA); Domroese, Michael K. (South St. Paul, MN); Hoffman, Joseph A. (Minneapolis, MN); Lindeman, David D. (Hudson, WI); Noel, Joseph-Robert-Gaetan (St-Hubert, CA); Radewald, Vern E. (Austin, TX); Ranger, Michel (Lachine, CA); Sudano, Anthony (Laval, CA); Trice, Jennifer L. (Eagan, MN); Turgeon, Thomas A. (Fridley, MN)
Titanium nitride thin films for minimizing multipactoring
Applying a thin film coating to the surface of a workpiece, in particular, applying a coating of titanium nitride to a klystron window by means of a crossed-field diode sputtering array. The array is comprised of a cohesive group of numerous small hollow electrically conducting cylinders and is mounted so that the open ends of the cylinders on one side of the group are adjacent a titanium cathode plate. The workpiece is mounted so as to face the open ends of the other side of the group. A magnetic field is applied to the array so as to be coaxial with the cylinders and a potential is applied across the cylinders and the cathode plate, the cylinders as an anode being positive with respect to the cathode plate. The cylinders, the cathode plate and the workpiece are situated in an atmosphere of nitrogen which becomes ionized such as by field emission because of the electric field between the cylinders and cathode plate, thereby establishing an anode-cathode discharge that results in sputtering of the titanium plate. The sputtered titanium coats the workpiece and chemically combines with the nitrogen to form a titanium nitride coating on the workpiece. Gas pressure, gas mixtures, cathode material composition, voltages applied to the cathode and anode, the magnetic field, cathode, anode and workpiece spacing, and the aspect ratio (ratio of length to inner diameter) of the anode cylinders, all may be controlled to provide consistent optimum thin film coatings of various compositions and thicknesses. Another facet of the disclosure is the coating of microwave components per se with titanium nitride to reduce multipactoring under operating conditions of the components.
Welch, Kimo M. (Mountain View, CA)
The state of the art of thin-film photovoltaics
Thin-film photovoltaic technologies, based on materials such as amorphous or polycrystalline silicon, copper indium diselenide, cadmium telluride, and gallium arsenide, offer the potential for significantly reducing the cost of electricity generated by photovoltaics. The significant progress in the technologies, from the laboratory to the marketplace, is reviewed. The common concerns and questions raised about thin films are addressed. Based on the progress to date and the potential of these technologies, along with continuing investments by the private sector to commercialize the technologies, one can conclude that thin-film PV will provide a competitive alternative for large-scale power generation in the future.
Surek, T.
Nanostructured Thin Film Electrolyte for Thin Film Solid Oxide Fuel Cells
Solid oxide fuel cells (SOFCs) are very attractive as energy generation devices because they are clean, reliable, and almost entirely pollution-free. SOFCs have flexible fuel selections compared with other fuel cell technologies. The main disadvantage of SOFCs is their high operating temperature (~1000�C for conventional SOFCs) which leads to cell cracking and formation of non-conducting compounds at electrolyte/electrode interfaces. Therefore, intermediate temperature SOFCs (ITSOFCs) in the range of 500-700 �C has attracted extensive research interests. To achieve high cell performance at reduced temperatures, it requires high-catalytic activity, high ionic conductivity, and comparable thermal expansion coefficient (TEC) of the cell components. To address the above issues, the research focuses on two main approaches (i.e., the interlayer approach and the electrolyte approach) in order to improve the overall cell performance. First, the design of a thin layer of a vertically-aligned nanocomposite (VAN) structure as an interlayer between the electrolyte and cathode is demonstrated. The development of the VAN structures consisted of the cathode material as a perovskite or ordered double perovskite structure, La0.5Sr0.5CoO3 (LSCO) or PrBaCo2O5 delta (PBCO), and the electrolyte material as a fluorite structure, Ce0.9Gd0.1O1.95 (CGO or GDC), were achieved for thin film solid oxide fuel cell (TFSOFCs). The VAN structure significantly improves the overall performance of the TFSOFC by increasing the interfacial area between the electrolyte and cathode and also acts as a transition layer that improves adhesion and relieves both thermal stress and lattice strain. Second, microstructural and electrical properties of Gd-doped CeO2 (GDC, Ce0.9Gd0.1O1.95) thin films electrolyte are studied for intermediate temperature solid oxide fuel cells (SOFCs). The GDC thin film electrolytes with different grain sizes and grain morphologies were prepared by varying the deposition parameters such as substrate temperature, oxygen partial pressure, target repetition rate, and laser ablation energy. The electrical property of the GDC thin film is strongly affected by the grain size. Third, bilayer electrolytes composed of a gadolinium-doped CeO2 (GDC) layer (~6 micrometer thickness) and an yttria-stabilized ZrO2 (YSZ) layer with various thicknesses (~330 nm, ~440 nm, and ~1 micrometer) are achieved by a pulsed laser deposition (PLD) technique for thin film solid oxide fuel cells (TFSOFCs). One effective approach is to incorporate YSZ thin film as a blocking layer in between the GDC and anode for preventing chemical reduction of GDC and electrical current leakage. This bilayer approach effectively improves the GDC's chemical/ mechanical stability and reduces the OCV loss under reducing conditions. The results suggest that the YSZ thin film serves as a blocking layer for preventing electrical current leakage in the GDC layer and also provides chemical, mechanical, and structural integrity in the cell, which leads to the overall enhanced performance.
Cho, Sungmee
Amelio Solar | Open Energy Information
low-cost, thin-film photovoltaic module technology, related product manufacturing and power-generation systems. References Amelio Solar1 LinkedIn Connections CrunchBase...
Solar Completes 10MW Thin Film Solar Power Plant for SempraT. ; (2008) Concentrating Solar Power�Technology, Cost, and2009). �Concentrating solar power plants of the southwest
Atmospheric-Pressure Chemical Vapor Deposition of Iron Pyrite Thin Films
Iron pyrite (cubic FeS{sub 2}) is a promising candidate absorber material for earth-abundant thin-film solar cells. In this report, single-phase, large-grain, and uniform polycrystalline pyrite thin films are fabricated on glass and molybdenum-coated glass substrates by atmospheric-pressure chemical vapor deposition (AP-CVD) using the reaction of iron(III) acetylacetonate and tert-butyl disulfide in argon at 300 C, followed by sulfur annealing at 500--550 C to convert marcasite impurities to pyrite. The pyrite-marcasite phase composition depends strongly on the concentration of sodium in the growth substrate and the sulfur partial pressure during annealing. Phase and elemental composition of the films are characterized by X-ray diffraction, Raman spectroscopy, Auger electron spectroscopy, secondary ion mass spectrometry, Rutherford backscattering spectrometry, and X-ray photoelectron spectroscopy. The in-plane electrical properties are surprisingly insensitive to phase and elemental impurities, with all films showing p-type, thermally activated transport with a small activation energy ({approx}30 meV), a room- temperature resistivity of {approx}1 {Omega} cm, and low mobility. These ubiquitous electrical properties may result from robust surface effects. These CVD pyrite thin films are well suited to fundamental electrical studies and the fabrication of pyrite photovoltaic device stacks.
Berry, Nicholas; Cheng, Ming; Perkins, Craig L.; Limpinsel, Moritz; Hemminger, John C.; Law, Matt (NREL); (UCI)
Functionalized multilayer thin films for protection against acutely toxic agents
The recently developed practice of spraying polyelectrolyte solutions onto a substrate in order to construct thin films via the Layer-by-Layer (LbL) technique has been further investigated and extended. In this process a ...
Krogman, Kevin Christopher
Polycrystalline Thin-Film Research: Cadmium Telluride (Fact Sheet)
Capabilities fact sheet that includes scope, core competencies and capabilities, and contact/web information for Polycrystalline Thin-Film Research: Cadmium Telluride at the National Center for Photovoltaics.
Properties and sensor performance of zinc oxide thin films
Reactively sputtered ZnO thin film gas sensors were fabricated onto Si wafers. The atmosphere dependent electrical response of the ZnO micro arrays was examined. The effects of processing conditions on the properties and ...
Min, Yongki, 1965-
Fluorination of amorphous thin-film materials with xenon fluoride
A method is disclosed for producing fluorine-containing amorphous semiconductor material, preferably comprising amorphous silicon. The method includes depositing amorphous thin-film material onto a substrate while introducing xenon fluoride during the film deposition process.
Weil, Raoul B. (Haifa, IL)
Biological, Electronic, and Functional Thin Films and Coatings II
Mar 4, 2013 ... Recent Developments in Biological, Electronic, and Functional Thin Films ... Improved Mobility and Transmittance of Room Temperature ... excellent scintillator for numerous applications in lasers, optical lens and radiography.
Shock Dynamics in Particle-Laden Thin Films
We present theory and experiments for thin film particle-laden flow on an incline. At higher particle concentration and inclination angle, a new phenomenon is observed in which a large particle-rich ridge forms at the ...
Dupuy, B.
Direct printing of lead zirconate titanate thin films
Thus far, use of lead zirconate titanate (PZT) in MEMS has been limited due to the lack of process compatibility with existing MEMS manufacturing techniques. Direct printing of thin films eliminates the need for photolithographic ...
Bathurst, Stephen, 1980-
Chemical vapor deposition of organosilicon and sacrificial polymer thin films
Chemical vapor deposition (CVD) produced films for a wide array of applications from a variety of organosilicon and organic precursors. The structure and properties of thin films were controlled by varying processing ...
Casserly, Thomas Bryan
Method for making surfactant-templated thin films
An evaporation-induced self-assembly method to prepare a porous, surfactant-templated, thin film by mixing a silica sol, a solvent, a surfactant, and an interstitial compound, evaporating a portion of the solvent to form a liquid, crystalline thin film mesophase material, and then removal of the surfactant template. Coating onto a substrate produces a thin film with the interstitial compound either covalently bonded to the internal surfaces of the ordered or disordered mesostructure framework or physically entrapped within the ordered or disordered mesostructured framework. Particles can be formed by aerosol processing or spray drying rather than coating onto a substrate. The selection of the interstitial compound provides a means for developing thin films for applications including membranes, sensors, low dielectric constant films, photonic materials and optical hosts.
Brinker, C. Jeffrey (Albuquerque, NM); Lu, Yunfeng (New Orleans, LA); Fan, Hong You (Albuquerque, NM)
Brinker, C. Jeffrey (Albuquerque, NM); Lu, Yunfeng (San Jose, CA); Fan, Hongyou (Albuquerque, NM)
Synthesis and Patterning of Calcium and Barium Niobate Thin Films ...
Epitaxial CBN thin films were deposited on MgO and NSTO substrates at 800�C under 1mTorr of oxygen pressure using Pulsed Laser Deposition technique.
Initiated chemical vapor deposition of functional polyacrylic thin films
Initiated chemical vapor deposition (iCVD) was explored as a novel method for synthesis of functional polyacrylic thin films. The process introduces a peroxide initiator, which can be decomposed at low temperatures (<200?C) ...
Mao, Yu, 1975-
Deriving Deformation Mechanisms in Nanocrystalline AuCu Thin Films
... in a SEM on nc gold and gold-copper thin films adherent to polymer substrate. .... Lithiation Mechanism of Individual SnO2 Nanowires in a Flooding Geometry.
This National Center for Photovoltaics sheet describes the capabilities of its polycrystalline thin-film research in the area of cadmium telluride. The scope and core competencies and capabilities are discussed.
Guided Self-Assembly of Gold Thin Films
Self-Assembly of Gold Thin Films Print Nanoparticles-man-made atoms with unique optical, electrical, and mechanical properties-have become key components in many fields of...
Dry-transfer of chemical vapour deposited nanocarbon thin films
equipment and measurement I thank Dr Xiulia Xu, high resolution transmission electron microscopy - Dr Caterina Ducati, Mr Sai Shivareddy and Dr Jamie Warner (Oxford University) and assistance with supercapacitor manufacturing and measurement - Mr (soon... that these thin films behave, in a macroscopic sense, similar to traditional c-axis conductive graphite and deviate toward tunnel dominated conduction with increasing degrees of network disorder. Various MWCNT-based thin film field emitters were considered...
Cole, Matthew Thomas
Lessons Learned from the Photovoltaic Manufacturing Technology/PV Manufacturing R&D and Thin Film PV Partnership Projects
As the U.S. Department of Energy's (DOE's) Solar Energy Technologies Program initiates new cost-shared solar energy R&D under the Solar America Initiative (SAI), it is useful to analyze the experience gained from cost-shared R&D projects that have been funded through the program to date. This report summarizes lessons learned from two DOE-sponsored photovoltaic (PV) projects: the Photovoltaic Manufacturing Technology/PV Manufacturing R&D (PVMaT/PVMR&D) project and the Thin-Film PV Partnership project. During the past 10-15 years, these two projects have invested roughly $330 million of government resources in cost-shared R&D and leveraged another $190 million in private-sector PV R&D investments. Following a description of key findings and brief descriptions of the PVMaT/PVMR&D and Thin-Film PV Partnership projects, this report presents lessons learned from the projects.
Margolis, R.; Mitchell, R.; Zweibel, K.
Modeling and control of thin film surface morphology: application to thin film solar cells
Lattice Kinetic Monte-Carlo Model. Chemical EngineeringLattice Kinetic Monte-Carlo Model. Chemical En- gineeringlattice kinetic monte carlo model. Chemical Engineering
Huang, Jianqiao
Chemically Deposited Zinc Selenide Thin Films
Phase Change Materials for Enhancing Heat Transfer in Thermal Energy Storage for Concentrating Solar Power (CSP) � Phase Field Simulation of�...
Thin Film Packaging Solutions for High Efficiency OLED Lighting Products
The objective of the 'Thin Film Packaging Solutions for High Efficiency OLED Lighting Products' project is to demonstrate thin film packaging solutions based on SiC hermetic coatings that, when applied to glass and plastic substrates, support OLED lighting devices by providing longer life with greater efficiency at lower cost than is currently available. Phase I Objective: Demonstrate thin film encapsulated working phosphorescent OLED devices on optical glass with lifetime of 1,000 hour life, CRI greater than 75, and 15 lm/W. Phase II Objective: Demonstrate thin film encapsulated working phosphorescent OLED devices on plastic or glass composite with 25 lm/W, 5,000 hours life, and CRI greater than 80. Phase III Objective: Demonstrate 2 x 2 ft{sup 2} thin film encapsulated working phosphorescent OLED with 40 lm/W, 10,000 hour life, and CRI greater than 85. This report details the efforts of Phase III (Budget Period Three), a fourteen month collaborative effort that focused on optimization of high-efficiency phosphorescent OLED devices and thin-film encapsulation of said devices. The report further details the conclusions and recommendations of the project team that have foundation in all three budget periods for the program. During the conduct of the Thin Film Packaging Solutions for High Efficiency OLED Lighting Products program, including budget period three, the project team completed and delivered the following achievements: (1) a three-year marketing effort that characterized the near-term and longer-term OLED market, identified customer and consumer lighting needs, and suggested prototype product concepts and niche OLED applications lighting that will give rise to broader market acceptance as a source for wide area illumination and energy conservation; (2) a thin film encapsulation technology with a lifetime of nearly 15,000 hours, tested by calcium coupons, while stored at 16 C and 40% relative humidity ('RH'). This encapsulation technology was characterized as having less than 10% change in transmission during the 15,000 hour test period; (3) demonstrated thin film encapsulation of a phosphorescent OLED device with 1,500 hours of lifetime at 60 C and 80% RH; (4) demonstrated that a thin film laminate encapsulation, in addition to the direct thin film deposition process, of a polymer OLED device was another feasible packaging strategy for OLED lighting. The thin film laminate strategy was developed to mitigate defects, demonstrate roll-to-roll process capability for high volume throughput (reduce costs) and to support a potential commercial pathway that is less dependent upon integrated manufacturing since the laminate could be sold as a rolled good; (5) demonstrated that low cost 'blue' glass substrates could be coated with a siloxane barrier layer for planarization and ion-protection and used in the fabrication of a polymer OLED lighting device. This study further demonstrated that the substrate cost has potential for huge cost reductions from the white borosilicate glass substrate currently used by the OLED lighting industry; (6) delivered four-square feet of white phosphorescent OLED technology, including novel high efficiency devices with 82 CRI, greater than 50 lm/W efficiency, and more than 1,000 hours lifetime in a product concept model shelf; (7) presented and or published more than twenty internal studies (for private use), three external presentations (OLED workshop-for public use), and five technology-related external presentations (industry conferences-for public use); and (8) issued five patent applications, which are in various maturity stages at time of publication. Delivery of thin film encapsulated white phosphorescent OLED lighting technology remains a challenging technical achievement, and it seems that commercial availability of thin, bright, white OLED light that meets market requirements will continue to require research and development effort. However, there will be glass encapsulated white OLED lighting products commercialized in niche markets during the 2008 calendar year. This commercializ
All Day Solar | Open Energy Information
stage company planning to manufacture flexible thin-film PV modules for vehicular rooftop applications. References All Day Solar1 LinkedIn Connections CrunchBase Profile...
Bangkok Solar Co Ltd | Open Energy Information
Co Ltd Jump to: navigation, search Name Bangkok Solar Co Ltd Place Chachoengsao, Thailand Zip 24140 Product Manufacturer of thin-film amorphous silicon modules, distributes in...
Understanding Thin Film Structure for the Rational Design of
Understanding Thin Film Structure for the Rational Design of Understanding Thin Film Structure for the Rational Design of High-performance Organic Semiconductors for Plastic Electronics Organic semiconductors are attracting considerable research interest due to their potential applications in low-cost electronics such as organic light emitting diode (OLED) displays, RF identification tags (RFID), smart cards and electronic paper. The development of p-conjugated materials, which are composed of alternating single and double chemical bonds, are the foundation of these applications. In the past decade research in this field has progressed to the extent that desirable charge transport in the organic semiconductor film in organic thin film transistors (OTFT) can be achieved through molecular design by selective placement of electron-rich, electron-withdrawing, and aromatic groups in different parts of the molecule. Although the electronic properties are easily tuned by molecular design, the molecular packing within the thin film and the film microstructure have a significant influence on the OTFT performance. Despite this importance, this interrelationship between molecular structure, thin film molecular packing and charge transport are only poorly understood.
Uncooled thin film pyroelectric IR detector with aerogel thermal isolation
Uncooled pyroelectric IR imaging systems, such as night vision goggles, offer important strategic advantages in battlefield scenarios and reconnaissance surveys. Until now, the current technology for fabricating these devices has been limited by low throughput and high cost which ultimately limit the availability of these sensor devices. We have developed and fabricated an alternative design for pyroelectric IR imaging sensors that utilizes a multilayered thin film deposition scheme to create a monolithic thin film imaging element on an active silicon substrate for the first time. This approach combines a thin film pyroelectric imaging element with a thermally insulating SiO{sub 2} aerogel thin film to produce a new type of uncooled IR sensor that offers significantly higher thermal, spatial, and temporal resolutions at a substantially lower cost per unit. This report describes the deposition, characterization and optimization of the aerogel thermal isolation layer and an appropriate pyroelectric imaging element. It also describes the overall integration of these components along with the appropriate planarization, etch stop, adhesion, electrode, and blacking agent thin film layers into a monolithic structure. 19 refs., 8 figs., 6 tabs.
Ruffner, J.A.; Clem, P.G.; Tuttle, B.A. [and others
Tandem photonic-crystal thin films surpassing Lambertian light-trapping limit over broad bandwidth and angular range
The maximum absorption of solar radiation over the broadest range of frequencies and incident angles using the thinnest material possible has important applications for renewable-energy generation. Complete random texturing of an optically-thick film's surface to increase the path length of scattered light rays, first proposed nearly thirty years ago, has thus far remained the most effective approach for photon absorption over the widest set of conditions. Recent thin-film nanostructured designs involving resonant wave effects of photons have explored the possibility of superior performance though as of yet no proposal satisfying the dual requirements of enhanced and robust absorption over a large fraction of the solar spectrum has been made. Here using recent advances in computational electrodynamics we describe a general strategy for the design of a silicon thin film applicable to photovoltaic cells based on a quasi-resonant approach to light trapping where two partially-disordered photonic-crystal slabs, s...
Oskooi, Ardavan; Noda, Susumu
Thin-film cadmium telluride photovoltaic cells. Final subcontract report, 1 November 1992--1 January 1994
This report describes work to develop and optimize radio-frequency (rf) sputtering for the deposition of thin films of cadmium telluride (CdTe) and related semiconductors for thin-film solar cells. Pulsed laser physical vapor deposition was also used for exploratory work on these materials, especially where alloying or doping are involved, and for the deposition of cadmium chloride layers. The sputtering work utilized a 2-in diameter planar magnetron sputter gun. The film growth rate by rf sputtering was studied as a function of substrate temperature, gas pressure, and rf power. Complete solar cells were fabricated on tin-oxide-coated soda-lime glass substrates. Currently, work is being done to improve the open-circuit voltage by varying the CdTe-based absorber layer, and to improve the short-circuit current by modifying the CdS window layer.
Compaan, A.D.; Bohn, R.G. [Toledo Univ., OH (United States)
Development of a computer model for polycrystalline thin-film CuInSe{sub 2} and CdTe solar cells. Annual subcontract report, 1 January 1990--31 December 1990
Gray, J.L.; Schwartz, R.J.; Lee, Y.J. [Purdue Univ., Lafayette, IN (United States)
A Better Steam Engine: Designing a Distributed Concentrating Solar Combined Heat and Power System
solar-electric system (typical for thin-film panels currently) plus a 58% efficient solar-thermal system (flat-plate efficiency
Norwood, Zachary Mills
Guided Self-Assembly of Gold Thin Films Print Guided Self-Assembly of Gold Thin Films Print Nanoparticles-man-made atoms with unique optical, electrical, and mechanical properties-have become key components in many fields of science. If nanoparticles could be coaxed into routinely assembling themselves into predictable complex structures and hierarchical patterns, devices could be mass-produced that are one thousand times smaller than today's microtechnologies. Berkeley Lab and UC Berkeley scientists have made progress toward this goal, successfully directing the self--assembly of nanoparticles into device-ready thin films, which have potential applications in fields ranging from computer memory storage to energy harvesting and storage, from catalysis to light management, and into the emerging new field of plasmonics.
Low Temperature Chemical Vapor Deposition Of Thin Film Magnets
A thin-film magnet formed from a gas-phase reaction of tetracyanoetheylene (TCNE) OR (TCNQ), 7,7,8,8-tetracyano-P-quinodimethane, and a vanadium-containing compound such as vanadium hexcarbonyl (V(CO).sub.6) and bis(benzene)vanalium (V(C.sub.6 H.sub.6).sub.2) and a process of forming a magnetic thin film upon at least one substrate by chemical vapor deposition (CVD) at a process temperature not exceeding approximately 90.degree. C. and in the absence of a solvent. The magnetic thin film is particularly suitable for being disposed upon rigid or flexible substrates at temperatures in the range of 40.degree. C. and 70.degree. C. The present invention exhibits air-stable characteristics and qualities and is particularly suitable for providing being disposed upon a wide variety of substrates.
Miller, Joel S. (Salt Lake City, UT); Pokhodnya, Kostyantyn I. (Salt Lake City, UT)
Ultrafast laser ablation of gold thin film targets
Ultrafast laser ablation of a gold thin film is studied and compared with that of a bulk target, with particular emphasis given to the process of nanoparticles generation. The process is carried out in a condition where a single laser shot removes all the irradiated film spot. The experimental results evidence interesting differences and, in particular, a reduction of the nanoparticles size, and a narrowing of a factor two of their size distribution in the case of ablation of a thin film target, a feature which we relate to a more uniform heating of the target material. We thus show that ultrashort laser ablation of thin films provides a promising way of controlling plume features and nanoparticles size.
Amoruso, S.; Ausanio, G.; Bruzzese, R. [Dipartimento di Scienze Fisiche, Universita degli Studi di Napoli Federico II, Complesso Universitario di Monte S. Angelo, Via Cintia, I-80126 Napoli (Italy); CNR-SPIN, Complesso Universitario di Monte S. Angelo, Via Cintia, I-80126 Napoli (Italy); Nedyalkov, N. N.; Atanasov, P. A. [Institute of Electronics, Bulgarian Academy of Sciences, 72 Tsaridradsko shose Boulevard, Sofia 1784 (Bulgaria); Wang, X. [CNR-SPIN, Complesso Universitario di Monte S. Angelo, Via Cintia, I-80126 Napoli (Italy)
Thin-film rechargeable lithium batteries for implantable devices
Thin films of LiCoO{sub 2} have been synthesized in which the strongest x-ray reflection is either weak or missing, indicating a high degree of preferred orientation. Thin-film solid state batteries with these textured cathode films can deliver practical capacities at high current densities. For example, for one of the cells 70% of the maximum capacity between 4.2 V and 3 V ({approximately}0.2 mAh/cm{sup 2}) was delivered at a current of 2 mA/cm{sup 2}. When cycled at rates of 0.1 mA/cm{sup 2}, the capacity loss was 0.001 %/cycle or less. The reliability and performance of Li-LiCoO{sub 2} thin-film batteries make them attractive for application in implantable devices such as neural stimulators, pacemakers, and defibrillators.
Bates, J.b.; Dudney, N.J.
Ram S Katiyar, University of Puerto Rico. Scope, The ... Optical Properties of Bifeo3: Polar Oxides for Fundamental Science and Solar Energy Applications.
SPUTTERED THIN FILM PHOTOVOLTAICS - Home - Energy ...
for photovoltaic (PV) applications .These processes result in films with better unif ormity over ... ultimately resulting in a more efficient solar ce ...
Development of a computer model for polycrystalline thin-film CuInSe{sub 2} and CdTe solar cells. Final subcontract report, 1 January 1991--31 December 1991
Method of improving field emission characteristics of diamond thin films
A method of preparing diamond thin films with improved field emission properties. The method includes preparing a diamond thin film on a substrate, such as Mo, W, Si and Ni. An atmosphere of hydrogen (molecular or atomic) can be provided above the already deposited film to form absorbed hydrogen to reduce the work function and enhance field emission properties of the diamond film. In addition, hydrogen can be absorbed on intergranular surfaces to enhance electrical conductivity of the diamond film. The treated diamond film can be part of a microtip array in a flat panel display.
Krauss, Alan R. (Naperville, IL); Gruen, Dieter M. (Downer Grove, IL)
Effects of humidity during photoprocessing on thin film metallization adhesion
Humidity effects during photoprocessing on tantalum/chromium/gold thin film networks (TFNs) were investigated. Humidity conditions at various process steps were controlled by placing either desiccant or water in handling containers for the TFNs. The TFNs photoprocessed in humid conditions had a much higher occurrence of metallization failures compared to TFNs processed in dry conditions. Ceramic surface defects were shown to cause pores in the thin films, and these pores enhanced corrosion susceptibility for the films. This study resulted in a desiccated storage process for production of TFNs.
Norwood, D.P.
Initiated chemical vapor deposition of polymeric thin films : mechanism and applications
Initiated chemical vapor deposition (iCVD) is a novel technique for depositing polymeric thin films. It is able to deposit thin films of application-specific polymers in one step without using any solvents. Its uniqueness ...
Chan, Kelvin, Ph. D. Massachusetts Institute of Technology
Characterization of LiNi?.?Mn?.?O? Thin Film Cathode Prepared by Pulsed Laser Deposition
LiNi?.?Mn?.?O? thin films have been grown by pulsed laser deposition (PLD) on stainless steel (SS) substrates. The crystallinity and structure of thin films were investigated by X-ray diffraction (XRD). Microstructure and ...
Xia, Hui
Orientation of MgO thin films on Si(001) prepared by pulsed laser deposition
Pulsed laser deposition method was employed to grow MgO thin films with preferred orientation on bare Si(100) and SiO?/Si(100) substrates. The orientation of MgO thin films was systematically investigated by varying ...
Zhu, Tie-Jun
The development of a thin-film rollforming process for pharmaceutical continuous manufacturing
In this thesis, a continuous rollforming process for the folding of thin-films was proposed and studied as a key step in the continuous manufacturing of pharmaceutical tablets. HPMC and PEG based polymeric thin-films were ...
Slaughter, Ryan (Ryan R.)
Thin-film multichip module packages for high-end IBM servers
A new generation of multilevel thin-film packages has been developed for IBM high-end S/390� and AS/400� systems. Thin-film structures in these packages are nonplanar and can be fabricated by either pattern electroplating ...
E. D. Perfecto; A. P. Giri; R. R. Shields; H. P. Longworth; J. R. Pennacchia; M. P. Jeanneret
Thin film cadmium telluride photovoltaic cells. Annual subcontract report, 23 July 1990--31 October 1991
Compaan, A.; Bohn, R. [Toledo Univ., OH (United States)
Development of Y-doped ZnO Thin Films via Novel Ink Jet Printing ...
Synthesis and Characterization of Plasma Polymerized Thin Films Deposited from Benzene and Hexamethyldisiloxane Using (PECVD) Method � Synthesis and�...
Some a priori estimates for a singular evolution equation arising in thin-film dynamics
Keywords: finite extinction time, global Harnack inequality, ill-posed problem, porous-medium equation, thin-film dynamics
Stephen H. Davis; Emmanuele DiBenedetto; David J. Diller
Outdoor Performance of a Thin-Film Gallium-Arsenide Photovoltaic Module
We deployed a 855 cm2 thin-film, single-junction gallium arsenide (GaAs) photovoltaic (PV) module outdoors. Due to its fundamentally different cell technology compared to silicon (Si), the module responds differently to outdoor conditions. On average during the test, the GaAs module produced more power when its temperature was higher. We show that its maximum-power temperature coefficient, while actually negative, is several times smaller in magnitude than that of a Si module used for comparison. The positive correlation of power with temperature in GaAs is due to temperature-correlated changes in the incident spectrum. We show that a simple correction based on precipitable water vapor (PWV) brings the photocurrent temperature coefficient into agreement with that measured by other methods and predicted by theory. The low operating temperature and small temperature coefficient of GaAs give it an energy production advantage in warm weather.
Silverman, T. J.; Deceglie, M. G.; Marion, B.; Cowley, S.; Kayes, B.; Kurtz, S.
Time-Resolved Magnetic Flux and AC-Current Distributions in Superconducting YBCO Thin Films and
Time-Resolved Magnetic Flux and AC-Current Distributions in Superconducting YBCO Thin Films magnetic field. We study the interaction behavior of YBCO thin films in an ac transport current and a dc the calibrated field profiles. The current density evolution in YBCO thin films is studied by TRMOI as a function
Lewis, Robert Michael
Microwave plasma assisted supersonic gas jet deposition of thin film materials
An apparatus for fabricating thin film materials utilizing high speed gas dynamics relies on supersonic free jets of carrier gas to transport depositing vapor species generated in a microwave discharge to the surface of a prepared substrate where the vapor deposits to form a thin film. The present invention generates high rates of deposition and thin films of unforeseen high quality at low temperatures.
Schmitt, III, Jerome J. (New Haven, CT); Halpern, Bret L. (Bethany, CT)
Amorphous silicon-carbon thin films
This study has shown that it is possible to produce nearly stoichiometric films of a-SiC:H with high hydrogen content by rf sputtering in an atmosphere of argon, propane, and hydrogen. The a-SiC films adhere to a variety of substrates and exhibit better thermal stability than a-Si:H films. The index of refraction is 2.8. The optical gap energy of these films is between 2.0 and 2.2 eV. A series of isochronal annealing steps show that optical gap energies decrease, optical absorption edge widths increase, and that the minimum optical density in the low absorption region increases with annealing above 450/sup 0/C. Infrared measurements show large absorptions at 2100, 1000, 750, and 650 cm/sup -1/ corresponding to SiH stretch, CH wagging, SiC stretch, and SiH wagging vibrational modes. The CH/sub n/ stretch mode near 2900 cm/sup -1/ is very small. Isochronal annealing causes a nearly continuous decrease in the integrated intensity of the SiH stretch mode at 2100 cm/sup -1/. The 2100 absorption peak shape may indicate the presence of SiH/sub 2/ in the film. Comparison of the 2100 and 750 absorption peaks show that the Si-C bonds are more heat resistant than the Si-H bonds. Annealing experiments reveal that the decrease in optical gap energy with increasing annealing temperature is probably not due to change in the Si-H bonds. Rather, the decrease is most likely due to changes or breaks in the C-H bonds and possibly the Si-C bonds. NMR results show that the films have high hydrogen concentrations. Also, NMR results and the integrated intensity for the SiH stretch mode give correct order of magnitude determination of the number and concentration of Si-H bonds in the a-SiC:H films.
Ward, J.F.
Interactions between radical growth precursors on plasma-deposited silicon thin-film surfaces
We present a detailed analysis of the interactions between growth precursors, SiH{sub 3} radicals, on surfaces of silicon thin films. The analysis is based on a synergistic combination of density functional theory calculations on the hydrogen-terminated Si(001)-(2x1) surface and molecular-dynamics (MD) simulations of film growth on surfaces of MD-generated hydrogenated amorphous silicon (a-Si:H) thin films. In particular, the authors find that two interacting growth precursors may either form disilane (Si{sub 2}H{sub 6}) and desorb from the surface, or disproportionate, resulting in the formation of a surface dihydride (adsorbed SiH{sub 2} species) and gas-phase silane (SiH{sub 4}). The reaction barrier for disilane formation is found to be strongly dependent on the local chemical environment on the silicon surface and reduces (or vanishes) if one/both of the interacting precursors is/are in a ''fast diffusing state,'' i.e., attached to fivefold coordinated surface Si atoms. Finally, activation energy barriers in excess of 1 eV are obtained for two chemisorbed (i.e., bonded to a fourfold coordinated surface Si atom) SiH{sub 3} radicals. Activation energy barriers for disproportionation follow the same tendency, though, in most cases, higher barriers are obtained compared to disilane formation reactions starting from the same initial configuration. MD simulations confirm that disilane formation and disproportionation reactions also occur on a-Si:H growth surfaces, preferentially in configurations where at least one of the SiH{sub 3} radicals is in a ''diffusive state.'' Our results are in agreement with experimental observations and results of plasma process simulators showing that the primary source for disilane in low-power plasmas may be the substrate surface.
Bakos, Tamas; Valipa, Mayur S.; Maroudas, Dimitrios [Department of Chemical Engineering, University of Massachusetts, Amherst, Massachusetts 01003-3110 (United States)
Thin Films and the Systems-Driven Approach
A systems-driven approach is used to discern tradeoffs between cost and efficiency improvements for various thin-film module technologies and designs. Prospects for reduced system cost via such strategies are enhanced as balance-of-systems costs decline, and some strategies are identified for greater research focus.
Method for double-sided processing of thin film transistors
This invention provides methods for fabricating thin film electronic devices with both front- and backside processing capabilities. Using these methods, high temperature processing steps may be carried out during both frontside and backside processing. The methods are well-suited for fabricating back-gate and double-gate field effect transistors, double-sided bipolar transistors and 3D integrated circuits.
Yuan, Hao-Chih (Madison, WI); Wang, Guogong (Madison, WI); Eriksson, Mark A. (Madison, WI); Evans, Paul G. (Madison, WI); Lagally, Max G. (Madison, WI); Ma, Zhenqiang (Middleton, WI)
Front and backside processed thin film electronic devices
Method of preparing thin film polymeric gel electrolytes
Novel hybrid thin film electrolyte, based on an organonitrile solvent system, which are compositionally stable, environmentally safe, can be produced efficiently in large quantity and which, because of their high conductivities .apprxeq.10.sup.-3 .OMEGA..sup.-1 cm.sup.-1 are useful as electrolytes for rechargeable lithium batteries.
Derzon, Dora K. (Albuquerque, NM); Arnold, Jr., Charles (Albuquerque, NM)
ITO Thin Films by RF Sputtering for Ethanol Sensing
The sensor for detection of ethanol vapours using RF sputter deposited ITO thin film on glass and Si substrates is reported. The principle of operation is the change of resistance of ITO film on exposure to ethanol vapours. The films were annealed at ... Keywords: Indium Tin Oxide, RF sputtering, ethanol sensor
Sudhir Chandra; H. J. Pandya; A. L. Vyas
Avalanches through windows: Multiscale visualization in magnetic thin films
Avalanches through windows: Multiscale visualization in magnetic thin films Alessandro Magni dynamics, but are strongly dependent on the size of the windows chosen. Here we investigate how to properly sub-window of the entire sample. Usually, windows of varying sizes are used, and the distributions
Sethna, James P.
This invention provides thin film devices that have been processed on their front- and backside. The devices include an active layer that is sufficiently thin to be mechanically flexible. Examples of the devices include back-gate and double-gate field effect transistors, double-sided bipolar transistors and 3D integrated circuits.
Evans, Paul G. (Madison, WI); Lagally, Max G. (Madison, WI); Ma, Zhenqiang (Middleton, WI); Yuan, Hao-Chih (Lakewood, CO); Wang, Guogong (Madison, WI); Eriksson, Mark A. (Madison, WI)
Perovskite phase thin films and method of making
The present invention comprises perovskite-phase thin films, of the general formula A.sub.x B.sub.y O.sub.3 on a substrate, wherein A is selected from beryllium, magnesium, calcium, strontium, and barium or a combination thereof; B is selected from niobium and tantalum or a combination thereof; and x and y are mole fractions between approximately 0.8 and 1.2. More particularly, A is strontium or barium or a combination thereof and B is niobium or tantalum or a combination thereof. Also provided is a method of making a perovskite-phase thin film, comprising combining at least one element-A-containing compound, wherein A is selected from beryllium, magnesium, calcium, strontium or barium, with at least one element-B-containing compound, wherein B niobium or tantalum, to form a solution; adding a solvent to said solution to form another solution; spin-coating the solution onto a substrate to form a thin film; and heating the film to form the perovskite-phase thin film.
Boyle, Timothy J. (Albuquerque, NM); Rodriguez, Mark A. (Albuquerque, NM)
Electroplating of Cu(Ag) thin films for interconnect applications
Electromigration effects in interconnect metallizations cause a need for materials with superior resistance against electromigration failure but with adequate electrical properties. In principle, Cu(Ag) alloys are potential candidates to become an interconnect ... Keywords: Copper-silver alloy thin film, Electrochemical deposition, Interconnect material
S. Strehle; S. Menzel; J. W. Bartha; K. Wetzig
Nanostructured thin films for solid oxide fuel cells
The goals of this work were to synthesize high performance perovskite based thin film solid oxide fuel cell (TF-SOFC) cathodes by pulsed laser deposition (PLD), to study the structural, electrical and electrochemical properties of these cathodes and to establish structure-property relations for these cathodes in order to further improve their properties and design new structures. Nanostructured cathode thin films with vertically-aligned nanopores (VANP) were processed using PLD. These VANP structures enhance the oxygen-gas phase diffusivity, thus improve the overall TF-SOFC performance. La0.5Sr0.5CoO3 (LSCO) and La0.4Sr0.6Co0.8Fe0.2O3 (LSCFO) were deposited on various substrates (YSZ, Si and pressed Ce0.9Gd0.1O1.95 (CGO) disks). Microstructures and properties of the nanostructured cathodes were characterized by transmission electron microscope (TEM), high resolution TEM (HRTEM), scanning electron microscope (SEM) and electrochemical impedance spectroscopy (EIS) measurements. A thin layer of vertically-aligned nanocomposite (VAN) structure was deposited in between the CGO electrolyte and the thin film LSCO cathode layer for TF-SOFCs. The VAN structure consists of the electrolyte and the cathode materials in the composition of (CGO) 0.5 (LSCO) 0.5. The self-assembled VAN nanostructures contain highly ordered alternating vertical columns formed through a one-step thin film deposition using a PLD technique. These VAN structures significantly increase the interface area between the electrolyte and the cathode as well as the area of active triple phase boundary (TPB), thus improving the overall TF-SOFC performance at low temperatures, as low as 400oC, demonstrated by EIS measurements. In addition, the binary VAN interlayer could act as the transition layer that improves the adhesion and relieves the thermal stress and lattice strain between the cathode and the electrolyte. The microstructural properties and growth mechanisms of CGO thin film prepared by PLD technique were investigated. Thin film CGO electrolytes with different grain sizes and crystal structures were prepared on single crystal YSZ substrates under different deposition conditions. The effect of the deposition conditions such as substrate temperature and laser ablation energy on the microstructural properties of these films are examined using XRD, TEM, SEM, and optical microscope. CGO thin film deposited above 500 �C starts to show epitaxial growth on YSZ substrates. The present study suggests that substrate temperature significantly influences the microstructure of the films especially film grain size.
Yoon, Jongsik
Improved blue response and efficiency of A-Si:H solar cells deposited from disilane using a dual-chamber plasma system
Thin film amorphous silicon solar cells with glass/SnO/sub 2//p/i/n/Al structures and 6 to 7% AM1 conversion efficiencies were fabricated at rapid deposition rates in a newly constructed dual-chamber glow discharge deposition system. The 500 nm thick intrinsic layer was deposited at the rate of 1.7 nm/s using disilane (Si/sub 2/H/sub 6/)-helium mixtures. This deposition rate is an order of magnitude greater than conventional high efficiency amorphous silicon solar cell depositions. Residual boron doping effects at the p/i interface can severely degrade cell performance particularly when the intrinsic layer is deposited in one chamber of the dual-chamber system and the intrinsic layer is deposited in the other chamber that is free of boron contaminants. Parameters such as electrode spacing, Si/sub 2/H/sub 6/ partial pressure and flow rate were optimized to produce uniform deposition over large areas. At the substrate temperature T/sub s/ selected for solar cell intrinsic layer deposition, the spin density was measured to be a minimum at 5 x 10/sup 15//cm/sup 3/. For a given T/sub s/, an intrinsic layer deposited from Si/sub 2/H/sub 6/ absorbs fewer photons and can generate less current under solar simulation than a similar film produced from monosilane. Identical solar cells were deposited in either the single-chamber mode or the dual-chamber mode for comparison. Single-chamber mode cells perform poorly over the visible wavelengths and hence produce low short circuit currents. The dual-chamber mode cells show a significant improvement in blue response and a factor of two increase in short circuit current over the single-chamber mode cells. Under short circuit conditions, 15 mA/cm/sup 2/ was generated from rapidly deposited (1.7 nm/s) cells from disilane and 18 mA/cm/sup 2/ from low deposition rate (0.18 nm/s) monosilane cells. These values are comparable to or better than those reported for similar cells by other groups.
Investigation of polycrystalline thin film CuInSe{sub 2} solar cells based on ZnSe windows. Annual subcontract report, 15 February, 1993--14 February, 1994
This report concerns studies of CIS solar cells based on ZnSe window layers. ZnSe/CIS devices are fabricated by growing ZnSe films by MOCVD onto Siemens CIS and graded absorber substrates. ZnSe films are grown by reacting H{sub 2}Se with a zinc adduct. ZnSe/CIS heterojunctions have been studied by depositing transparent aluminum contacts onto ZnSe. These studies indicate that ZnSe/CIS solar cells can be fabricated with an efficiency greater than 14%. Open circuit voltages are typically larger than 500 mV and the optimum range of ZnSe film thickness for maximum efficiency is between 100 {angstrom} and 250 {angstrom}. Photocurrents are significantly reduced as the film thickness exceeds 250 {angstrom}. Photoluminescence spectroscopy has been utilized to characterize the physical nature of CIS substrate surfaces, and ZnSe-CIS interfaces. These studies indicate that a segregated phase(s) exists at the surface of as received Siemens substrates. Additionally, it is determined that the segregated phase(s) still exist after the ZnSe growth process. To date, sputtered ZnO top contact layers have caused degradation of the photovoltaic properties of the ZnSe/CIS structure. Investigations of the effects of MOCVD grown ZnO upon ZnSe/CIS structures will soon be initiated. To establish the feasibility of ZnSe as a window layer, cells have been fabricated by incorporating a protective layer of CdS between the ZnSe and ZnO. A total area efficiency of 11% was obtained with such a structure.
Olsen, L.C. [Washington State Univ., Richland, WA (United States)
Polycrystalline thin-film technology: Recent progress in photovoltaics
Polycrystalline thin films have made significant technical progress in the past year. Three of these materials that have been studied extensively for photovoltaic (PV) power applications are copper indium diselenide (CuInSe{sub 2}), cadmium telluride (CdTe), and thin-film polycrystalline silicon (x-Si) deposited on ceramic substrates. The first of these materials, polycrystalline thin-film CuInSe{sub 2}, has made some rapid advances in terms of high efficiency and long-term reliability. For CuInSe{sub 2} power modules, a world record has been reported on a 0.4-m{sup 2} module with an aperture-area efficiency of 10.4% and a power output of 40.4 W. Additionally, outdoor reliability testing of CuInSe{sub 2} modules, under both loaded and open-circuit conditions, has resulted in only minor changes in module performance after more than 1000 days of continuous exposure to natural sunlight. CdTe module research has also resulted in several recent improvements. Module performance has been increased with device areas reaching nearly 900 cm{sup 2}. Deposition has been demonstrated by several different techniques, including electrodeposition, spraying, and screen printing. Outdoor reliability testing of CdTe modules was also carried out under both loaded and open-circuit conditions, with more than 600 days of continuous exposure to natural sunlight. These tests were also encouraging and indicated that the modules were stable within measurement error. The highest reported aperture-area module efficiency for CdTe modules is 10%; the semiconductor material was deposited by electrodeposition. A thin-film CdTe photovoltaic system with a power output of 54 W has been deployed in Saudi Arabia for water pumping. The Module Development Initiative has made significant progress in support of the Polycrystalline Thin-Film Program in the past year, and results are presented in this paper.
Thinner Film Silicon Solar Cells - Energy Innovation Portal
Technology Marketing Summary Berkeley Lab scientists have designed a new approach to create thin film silicon solar cells with a potential increase in ...
Formosun Solar Corp | Open Energy Information
Corp. Place Hsinchu County, Taiwan Zip 303-51 Sector Solar Product Thin-film solar cell producer based in Taiwan. References Formosun Solar Corp.1 LinkedIn Connections...
AOS Solar Inc | Open Energy Information
AOS Solar Inc Jump to: navigation, search Name AOS Solar Inc Product Manufacturer of thin-film silicon-on-glass. References AOS Solar Inc1 LinkedIn Connections CrunchBase...
Investigation of polycrystalline thin-film CuInSe{sub 2} solar cells based on ZnSe windows. Annual subcontract report, 15 Febraury 1992--14 February 1993
Investigations of ZnSe/CIS solar cells are being carried out in an effort to improve the efficiencies CIS cells and to determine if ZnSe is a viable alternative to CdS as a window material. MOCVD growth of ZnSe is accomplished in a SPIRE 500XT reactor housed in the Electronic Materials Laboratory at WSU Tri-Cities by reacting a zinc adduct with H{sub 2}Se. Conductive n-type ZnSe is grown by using iodine as a dopant. Ethyliodide was mixed with helium and installed on one of the gas lines to the system. ZnSe films have been grown on CIS substrates at 200{degrees}C to 250{degrees}C. ZnO is also being deposited by MOCVD by reacting tetrahydrofuran (THF) with a zinc adduct. ZnSe/CIS heterojunctions have been studied by growing n-ZnSe films onto 2 cm x 2 cm CIS substrates diced from materials supplied by Siemens and then depositing an array of aluminum circular areas 2.8.mm in diameter on top of the ZnSe to serve as contacts. Al films are deposited with a thickness of 80 to l00 {angstrom}so that light can pass through the film, thus allowing the illuminated characteristics of the ZnSe/CIS junction to be tested. Accounting for the 20 to 25 % transmittance through the Al film into the ZnSe/CIS structure, current devices have estimated, active-area AM1.5 efficiencies of 14 %. Open circuit voltages > 500 mV are often attained.
Olsen, L C [Washington State Univ. at Tri-Cities, Richland, WA (United States)
AxunTek Solar Energy | Open Energy Information
AxunTek Solar Energy Jump to: navigation, search Name AxunTek Solar Energy Place Taiwan Sector Solar Product Taiwan-based CIGS thin film solar cell producer. References AxunTek...
Search for the Factors Determining the Photodegradation in High Efficiency a-Si:H Solar Cells: Final Subcontract Report, 28 January 1998 - 15 August 2001
This report describes continuing studies on photoluminescence (PL), electroluminescence (EL), Raman, and nuclear magnetic resonance (NMR) by the University of North Carolina-Chapel Hill during the three years and the extension period. Systematic studies on the transition materials and their solar cells and a review of the photo-induced structural changes in correlation to the electronic degradation have led to better understanding of the factors determining the photodegradation in a-Si:H solar cells. NHR established significant differences, as in the bonding of hydrogen in the hot-wire- and plasma-deposited amorphous silicon.
Han, D.
EPOD Solar Inc | Open Energy Information
EPOD Solar Inc EPOD Solar Inc Place Kelowna, British Columbia, Canada Zip V1V 2L9 Sector Solar Product British Columbia-based thin-film a-Si PV maker as well as engineering, manufacturing and solar system installation company focused on large-scale project development. Coordinates 49.886815°, -119.496599° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":49.886815,"lon":-119.496599,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}
Pulsed laser processing of high temperature superconducting thin films
Systematic studies of the effects of pulsed laser deposition processing parameters on plume dynamics and resultant film properties have been performed. Plume angular distributions, cos{sup m}({theta}), were observed to be variable between 1 > m > 10 depending on laser energy density and spot size. Under optimized conditions, epitaxial, superconducting thin films could be grown in-situ on a variety of single-crystal substrates. High quality, 200 nm thick films were obtained at deposition rates approaching 15 nm/sec. Additionally, the patterning of YBa{sub 2}Cu{sub 3}O{sub 7-x} thin films has been achieved by a process which combines thermal oxygen diffusion and laser annealing. This process is performed under relatively mild conditions which allows the structural integrity of the films to be preserved. 9 refs., 6 figs.
Muenchausen, R.E.; Dye, R.C.; Estler, R.C.; Foltyn, S.; Garcia, A.R.; Hubbard, K.M.; Nogar, N.S.; Wu, X.D. (Los Alamos National Lab., NM (USA)); Carim, A.; Mukherjee, A.; Brueck, S.R.J. (New Mexico Univ., Albuquerque, NM (USA))
Characterization of Thin Films by XAFS: Application to Spintronics Materials
X-ray absorption fine structure (XAFS) has proven very valuable in characterizing thin films. This is illustrated with some examples from the area of diluted magnetic semiconductor (DMS) materials for spintronics applications. A promising route to DMS materials is doping of oxides such as TiO2 and ZnO with magnetic atoms such as Co. These can be grown as epitaxial thin films on various substrates. XAFS is especially valuable for characterizing the dopant atoms. The near edge region is sensitive to the symmetry of the bonding and valence of the dopants, and the extended XAFS can determine the details of the lattice site. XAFS is also valuable for detecting metallic nanoparticles. These can be difficult to detect by other methods, and can give a spurious magnetic signal. The power of XAFS is illustrated by examples from studies on Co doped ZnO films.
Heald, Steve M.; Kaspar, Tiffany C.; Droubay, Timothy; Chambers, Scott A.
Thin-Film Reliability Trends Toward Improved Stability
Long-term, stable performance of photovoltaic (PV) modules will be increasingly important to their successful penetration of the power grid. This paper summarizes more than 150 thin-film and more than 1700 silicon PV degradation rates (R{sub d}) quoted in publications for locations worldwide. Partitioning the literature results by technology and date of installation statistical analysis shows an improvement in degradation rate especially for thin-film technologies in the last decade. A CIGS array deployed at NREL for more than 5 years that appears to be stable supports the literature trends. Indoor and outdoor data indicate undetectable change in performance (0.2 {+-} 0.2 %/yr). One module shows signs of slight degradation from what appears to be an initial manufacturing defect, however it has not affected the overall system performance.
Jordan, D. C.; Kurtz, S. R.
Thin-Film Reliability Trends Toward Improved Stability: Preprint
Long-term, stable performance of photovoltaic (PV) modules will be increasingly important to their successful penetration of the power grid. This paper summarizes more than 150 thin-film and more than 1700 silicon PV degradation rates (Rd) quoted in publications for locations worldwide. Partitioning the literature results by technology and date of installation statistical analysis shows an improvement in degradation rate especially for thin-film technologies in the last decade. A CIGS array deployed at NREL for more than 5 years that appears to be stable supports the literature trends. Indoor and outdoor data indicate undetectable change in performance (0.2+/-0.2 %/yr). One module shows signs of slight degradation from what appears to be an initial manufacturing defect, however it has not affected the overall system performance.
Thin film photovoltaic device and process of manufacture
Provided is a thin film photovoltaic device and a method of manufacturing the device. The thin film photovoltaic device comprises a film layer having particles which are smaller than about 30 microns in size held in an electrically insulating matrix material to reduce the potential for electrical shorting through the film layer. The film layer may be provided by depositing preformed particles onto a surrogate substrate and binding the particles in a film-forming matrix material to form a flexible sheet with the film layer. The flexible sheet may be separated from the surrogate substrate and cut into flexible strips. A plurality of the flexible strips may be located adjacent to and supported by a common supporting substrate to form a photovoltaic module having a plurality of electrically interconnected photovoltaic cells. 13 figs.
Albright, S.P.; Chamberlin, R.
Provided is a thin film photovoltaic device and a method of manufacturing the device. The thin film photovoltaic device comprises a film layer having particles which are smaller than about 30 microns in size held in an electrically insulating matrix material to reduce the potential for electrical shorting through the film layer. The film layer may be provided by depositing preformed particles onto a surrogate substrate and binding the particles in a film-forming matrix material to form a flexible sheet with the film layer. The flexible sheet may be separated from the surrogate substrate and cut into flexible strips. A plurality of the flexible strips may be located adjacent to and supported by a common supporting substrate to form a photovoltaic module having a plurality of electrically interconnected photovoltaic cells.
Albright, Scot P. (Lakewood, CO); Chamberlin, Rhodes (El Paso, TX)
Method for formation of thin film transistors on plastic substrates
A process for formation of thin film transistors (TFTs) on plastic substrates replaces standard thin film transistor fabrication techniques, and uses sufficiently lower processing temperatures so that inexpensive plastic substrates may be used in place of standard glass, quartz, and silicon wafer-based substrates. The process relies on techniques for depositing semiconductors, dielectrics, and metals at low temperatures; crystallizing and doping semiconductor layers in the TFT with a pulsed energy source; and creating top-gate self-aligned as well as back-gate TFT structures. The process enables the fabrication of amorphous and polycrystalline channel silicon TFTs at temperatures sufficiently low to prevent damage to plastic substrates. The process has use in large area low cost electronics, such as flat panel displays and portable electronics.
Carey, Paul G. (Mountain View, CA); Smith, Patrick M. (San Ramon, CA); Sigmon, Thomas W. (Portola Valley, CA); Aceves, Randy C. (Livermore, CA)
Status of High Performance PV: Polycrystalline Thin-Film Tandems
The High-Performance Photovoltaic (HiPerf PV) Project was initiated by the U.S. Department of Energy to substantially increase the viability of photovoltaics (PV) for cost-competitive applications so that PV can contribute significantly to our energy supply and our environment. The HiPerf PV Project aims at exploring the ultimate performance limits of existing PV technologies, approximately doubling their sunlight-to-electricity conversion efficiencies during its course. This work includes bringing thin-film cells and modules toward 25% and 20% efficiencies, respectively, and developing multijunction concentrator cells and modules able to convert more than one-third of the sun's energy to electricity (i.e., 33% efficiency). This paper will address recent accomplishments of the NREL in-house research effort involving polycrystalline thin-film tandems, as well as the research efforts under way in the subcontracted area.
Symko-Davies, M.
Thin film battery and method for making same
Described is a thin-film battery, especially a thin-film microbattery, and a method for making same having application as a backup or primary integrated power source for electronic devices. The battery includes a novel electrolyte which is electrochemically stable and does not react with the lithium anode and a novel vanadium oxide cathode. Configured as a microbattery, the battery can be fabricated directly onto a semiconductor chip, onto the semiconductor die or onto any portion of the chip carrier. The battery can be fabricated to any specified size or shape to meet the requirements of a particular application. The battery is fabricated of solid state materials and is capable of operation between [minus]15 C and 150 C. 9 figs.
Bates, J.B.; Dudney, N.J.; Gruzalski, G.R.; Luck, C.F.
Described is a thin-film battery, especially a thin-film microbattery, and a method for making same having application as a backup or primary integrated power source for electronic devices. The battery includes a novel electrolyte which is electrochemically stable and does not react with the lithium anode and a novel vanadium oxide cathode Configured as a microbattery, the battery can be fabricated directly onto a semiconductor chip, onto the semiconductor die or onto any portion of the chip carrier. The battery can be fabricated to any specified size or shape to meet the requirements of a particular application. The battery is fabricated of solid state materials and is capable of operation between -15.degree. C. and 150.degree. C.
Bates, John B. (Oak Ridge, TN); Dudney, Nancy J. (Knoxville, TN); Gruzalski, Greg R. (Oak Ridge, TN); Luck, Christopher F. (Knoxville, TN)
Effects of acetylacetone additions on PZT thin film processing
Sol-gel processing methods are frequently used for the fabrication of lead zirconate titanate (PZT) thin films for many electronic applications. Our standard approach for film fabrication utilizes lead acetate and acetic acid modified metal alkoxides of zirconium and titanium in the preparation of our precursor solutions. This report highlights some of our recent results on the effects of the addition of a second chelating ligand, acetylacetone, to this process. The authors discuss the changes in film drying behavior, densification and ceramic microstructure which accompany acetylacetone additions to the precursor solution and relate the observed variations in processing behavior to differences in chemical precursor structure induced by the acetylacetone ligand. Improvements in thin film microstructure, ferroelectric and optical properties are observed when acetylacetone is added to the precursor solution.
Schwartz, R.W.; Assink, R.A.; Dimos, D.; Sinclair, M.B.; Boyle, T.J.; Buchheit, C.D.
Eddy Current Testing for Detecting Small Defects in Thin Films
Presented here is a technique of using Eddy Current based Giant Magneto-Resistance sensor (GMR) to detect surface and sub-layered minute defects in thin films. For surface crack detection, a measurement was performed on a copper metallization of 5-10 microns thick. It was done by scanning the GMR sensor on the surface of the wafer that had two scratches of 0.2 mm, and 2.5 mm in length respectively. In another experiment, metal coatings were deposited over the layers containing five defects with known lengths such that the defects were invisible from the surface. The limit of detection (resolution), in terms of defect size, of the GMR high-resolution Eddy Current probe was studied using this sample. Applications of Eddy Current testing include detecting defects in thin film metallic layers, and quality control of metallization layers on silicon wafers for integrated circuits manufacturing.
Obeid, Simon; Tranjan, Farid M. [Electrical and Computer Engineering Department, UNCC (United States); Dogaru, Teodor [Albany Instruments, 426-O Barton Creek, Charlotte, NC 28262 (United States)
Engineering Thin-Film Oxide Interfaces | Advanced Photon Source
Novel Materials Become Multifunctional at the Ultimate Quantum Limit Novel Materials Become Multifunctional at the Ultimate Quantum Limit Outsmarting Flu Viruses How Lead-Free Solder (Mis)Behaves under Stress Dynamics of Polymer Chains Atop Different Materials Priming the Pump in the Fight against Drug-Resistant Tuberculosis Science Highlights Archives: 2013 | 2012 | 2011 | 2010 2009 | 2008 | 2007 | 2006 2005 | 2004 | 2003 | 2002 2001 | 2000 | 1998 | Subscribe to APS Science Highlights rss feed Engineering Thin-Film Oxide Interfaces NOVEMBER 12, 2012 Bookmark and Share LAO thin films on STO substrates are depicted in the top schematics (LAO indicated by blue spheres, STO by green spheres). The top left-hand panel demonstrates a chemically broad interface resulting from conventional growth in a low pressure oxygen environment. In contrast, the top
Experimental thin film deposition and surface analysis techniques
An attempt has been made to present some of the thin-film deposition and surface analysis techniques which may be useful in growing superionic conducting materials. Emphasis is made on the importance of being careful in selecting process parameters and materials in order to produce films with properties outlined in this article. Also, special care should be given to proper consideration of grain boundary effects.
Collins, W.E.; Rambabu, B.
Preparation of redox polymer cathodes for thin film rechargeable batteries
The present invention relates to the manufacture of thin film solid state electrochemical devices using composite cathodes comprising a redox polymer capable of undergoing oxidation and reduction, a polymer solid electrolyte and conducting carbon. The polymeric cathode material is formed as a composite of radiation crosslinked polymer electrolytes and radiation crosslinked redox polymers based on polysiloxane backbones with attached organosulfur side groups capable of forming sulfur-sulfur bonds during electrochemical oxidation.
Skotheim, T.A.; Lee, H.S.; Okamoto, Yoshiyuki.
Growth and Characterization of Epitaxial Oxide Thin Films
of these morphological changes was found to be dependent on a number of factors including deposition rates, flux and energy of bombarding ions, and the average angle of incidence of Glow Discharge Glow Discharge -V (DC) Cathode (Target) Insulation Substrates Anode Vacuum... techniques such as reflected high energy electron diffraction (RHEED) and low energy electron diffraction (LEED) can give valuable information about the initial growth mechanisms and surface structure of the very thin films during growth in an in-situ manner...
Garg, Ashish
Synthesis of thin films and materials utilizing a gaseous catalyst
A method for the fabrication of nanostructured semiconducting, photoconductive, photovoltaic, optoelectronic and electrical battery thin films and materials at low temperature, with no molecular template and no organic contaminants. High-quality metal oxide semiconductor, photovoltaic and optoelectronic materials can be fabricated with nanometer-scale dimensions and high dopant densities through the use of low-temperature biologically inspired synthesis routes, without the use of any biological or biochemical templates.
Morse, Daniel E; Schwenzer, Birgit; Gomm, John R; Roth, Kristian M; Heiken, Brandon; Brutchey, Richard
Hysteresis in Thin-Film Rechargeable Lithium Batteries
Discharge - charge cycling of thin-film rechargeable lithium batteries with an amorphous or nanocrystalline LiXMn2.Y04 cathode reveals evidence for a true hysteresis in the lithium insertion reaction. This is compared with an apparent hysteresis attributed to a kinetically hindered phase transition near 3 V for batteries with either a crystalline or a nanocrystalline LiJ@Yo4 cathode.
Bates, J.B.; Dudney, N.J.; Evans, C.D.; Hart, F.X.
Fabrication and testing of thermoelectric thin film devices
Two thin-film thermoelectric devices are experimentally demonstrated. The relevant thermal loads on the cold junction of these devices are determined. The analytical form of the equation that describes the thermal loading of the device enables one to model the performance based on the independently measured electronic properties of the films forming the devices. This model elucidates which parameters determine device performance, and how they can be used to maximize performance.
Wagner, A.V.; Foreman, R.J.; Summers, L.J.; Barbee, T.W. Jr.; Farmer, J.C. [Lawrence Livermore National Lab., CA (United States). Chemistry and Materials Science Dept.
Substrates suitable for deposition of superconducting thin films
A superconducting system for the lossless transmission of electrical current comprising a thin film of superconducting material Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x epitaxially deposited upon a KTaO.sub.3 substrate. The KTaO.sub.3 is an improved substrate over those of the prior art since the it exhibits small lattice constant mismatch and does not chemically react with the superconducting film.
Formation of thin-film resistors on silicon substrates
The formation of thin-film resistors by the ion implantation of a metallic conductive layer in the surface of a layer of phosphosilicate glass or borophosphosilicate glass which is deposited on a silicon substrate. The metallic conductive layer materials comprise one of the group consisting of tantalum, ruthenium, rhodium, platinum and chromium silicide. The resistor is formed and annealed prior to deposition of metal, e.g. aluminum, on the substrate.
Schnable, George L. (Montgomery County, PA); Wu, Chung P. (Hamilton Township, Mercer County, NJ)
Optical sensors and multisensor arrays containing thin film electroluminescent devices
Optical sensor, probe and array devices for detecting chemical biological, and physical analytes. The devices include an analyte-sensitive layer optically coupled to a thin film electroluminescent layer which activates the analyte-sensitive layer to provide an optical response. The optical response varies depending upon the presence of an analyte and is detected by a photodetector and analyzed to determine the properties of the analyte.
Aylott, Jonathan W. (Ann Arbor, MI); Chen-Esterlit, Zoe (Ann Arbor, MI); Friedl, Jon H. (Ames, IA); Kopelman, Raoul (Ann Arbor, MI); Savvateev, Vadim N. (Ames, IA); Shinar, Joseph (Ames, IA)
Geometric shape control of thin film ferroelectrics and resulting structures
A monolithic crystalline structure and a method of making involves a semiconductor substrate, such as silicon, and a ferroelectric film, such as BaTiO.sub.3, overlying the surface of the substrate wherein the atomic layers of the ferroelectric film directly overlie the surface of the substrate. By controlling the geometry of the ferroelectric thin film, either during build-up of the thin film or through appropriate treatment of the thin film adjacent the boundary thereof, the in-plane tensile strain within the ferroelectric film is relieved to the extent necessary to permit the ferroelectric film to be poled out-of-plane, thereby effecting in-plane switching of the polarization of the underlying substrate material. The method of the invention includes the steps involved in effecting a discontinuity of the mechanical restraint at the boundary of the ferroelectric film atop the semiconductor substrate by, for example, either removing material from a ferroelectric film which has already been built upon the substrate, building up a ferroelectric film upon the substrate in a mesa-shaped geometry or inducing the discontinuity at the boundary by ion beam deposition techniques.
McKee, Rodney A. (Kingston, TN); Walker, Frederick J. (Oak Ridge, TN)
Low resistance thin film organic solar cell electrodes
A method which lower the series resistance of photosensitive devices includes providing a transparent film of a first electrically conductive material arranged on a transparent substrate; depositing and patterning a mask over the first electrically conductive material, such that openings in the mask have sloping sides which narrow approaching the substrate; depositing a second electrically conductive material directly onto the first electrically conductive material exposed in the openings of the mask, at least partially filling the openings; stripping the mask, leaving behind reentrant structures of the second electrically conductive material which were formed by the deposits in the openings of the mask; after stripping the mask, depositing a first organic material onto the first electrically conductive material in between the reentrant structures; and directionally depositing a third electrically conductive material over the first organic material deposited in between the reentrant structures, edges of the reentrant structures aligning deposition so that the third electrically conductive material does not directly contact the first electrically conductive material, and does not directly contact the second electrically conductive material.
Forrest, Stephen (Princeton, NJ); Xue, Jiangeng (Piscataway, NJ)
Boron arsenide thin film solar cell development. Final report
Pyrolytic decomposition of diborane and arsine has been used in attempts to grow polycrystalline BAs films. This method, however, produced only amorphous films for deposition temperatures below 920/sup 0/C and polycrystalline boron subarsenide (B/sub 12/As/sub 2/) flms for deposition temperatures above this value. The amorphous films have been determined to have a significant arsenic content but the actual stoichiometry was not obtained. The films were adherent on single crystal sapphire (0001), (111) silicon, (0001) SiC, and polycrystalline SiC but were found not to be adherent to substrates of fused quartz, tungsten, and molybdenum. It was also found that all films deposited above 650/sup 0/C were p-type while those deposited below 600/sup 0/C were usually n-type. Polycrystalline BAs and B/sub 12/As/sub 2/ was produced by reaction of the elements in a closed tube. The amorphous films showed an indirect or non-direct optical bandgap from 1.0 to 1.7 eV with the most probable values between 1.2 to 1.4 eV. The crystalline BAs powder shows a bandgap near 1.0 eV. Photoconductance time constants have been measured for films deposited on (0001) sapphire and (0001) SiC. Attempts at doping the amorphous films were generally unsuccessful. A polycrystalline powder sample was successfully doped with sulfur. Attempts were made to produce a Schottky barrier diode by evaporating Al dots onto an amorphous film on graphite without a post-evaporation anneal. An MIS structure was also attempted by baking an amorphous film in air at 280/sup 0/C before evaporation of aluminum. Although nonlinear characteristics were obtained, none of the devices showed any photovoltaic response. A p-type amorphous film was deposited on an n-type silicon substrate to form a p-n heterojunction. This device did exhibit a photovoltaic response but it is believed that the photogeneration was occurring primarily in the silicon substrate.
Infrared characteristics of VO{sub 2} thin films for smart window and laser protection applications
Vanadium dioxide (VO{sub 2}) films with a low semiconductor-to-metal transition temperature of 45 Degree-Sign C were fabricated through direct current magnetron sputtering followed by a post-annealing. Atomic force microscopy measurements show that the VO{sub 2} grain size is about one hundred of nanometers. Infrared (IR) characteristic is well investigated by applying a He-Ne laser power intensity measurement, and the result reveals that the VO{sub 2} film exhibits excellent IR switching property. Furthermore, solar smart window and laser protection experiments demonstrate that the obtained VO{sub 2} thin film is a promising material for the application in related fields.
Huang Zhangli; Chen Sihai; Lv Chaohong; Huang Ying; Lai Jianjun [Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China)