This invention introduces carbon-biomaterial nanohybrids for use in high-performance, low-cost optoelectronic devices such as infrared detectors.
Thermal sensing devices such as thermographic cameras make use of infrared (IR) detectors that can be either cooled or uncooled. Uncooled IR detectors are more practical and cost-effective for typical applications, but their performance is limited by the properties of their key materials (often conventional semiconductors such as vanadium oxide, VO2). Single-walled carbon nanotube (SWCNT)-based photodetectors have received strong attention in the past two decades based on their strong light absorption, efficiency, and low cost. However, the photoexcited electron-hole pairs (or excitons) in SWCNTs have unusually high binding energy, which hinders the excitons' dissociation into photocurrents. An effective exciton dissociation mechanism therefore represents a critical challenge toward high-performance CNT-based IR detectors. Previous research has shown that SWCNT-polymer nanohybrids form heterojunctions that improve performance. The present invention provides further improvement by replacing the polymer with biological macromolecules.
To learn more about the technology a published manuscript (pdf) is available for download.
Low-cost uncooled photodetectors for use in thermal sensing devices.
The feasibility of this invention has been demonstrated by KU researchers using the Cytochrome complex (Cyt c) biomolecule. Solutions of Cyt c and SWCNTs were mixed to promote self-assembly of SWCNT/Cyt c hybrid building blocks (helical wrapping of Cyt c around each SWCNT). The resulting thin films provide a composite of well-dispersed heterojunctions. When light impinges onto the photodetector, excitons generate in the SWCNTs and rapidly diffuse to the heterojunction interface where the Cyt c accepts the electrons and conducts to the external electrode.
Near infrared (NIR) responsivity of this invention has been measured at levels more than two orders of magnitude better than SWCNT-polymer hybrids. This result suggests that SWCNT-biomolecule hybrids may lead to uncooled IR detectors with unprecedented performance.
CNT-based photodetectors show great potential to outperform conventional semiconductor-based photodetectors. This invention presents the best performance yet achieved using CNTs and thus presents a promising basis for future photodetector technology.
Photonics, optoelectronics, and other electronic devices.