SEARCH · Engineering Papers
Results for “photoconductivity”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Transferable GeSn ribbon photodetectors for high-speed short-wave infrared photonic applications
We experimentally demonstrate a low-cost transfer process of GeSn ribbons to insulating substrates for short-wave infrared (SWIR) sensing/imaging applications. By releasing the original compressive GeSn layer to nearly fully relaxed state GeSn ribbons, the room-temperature spectral response of the photodetector is further extended to 3.2 μm, which can cover the entire SWIR range. Compared with the as-grown GeSn reference photodetectors, the fabricated GeSn ribbon photodetectors have a fivefold improvement in the light-to-dark current ratio, which can improve the detectivity for high-performance photodetection. The transient performance of a GeSn ribbon photodetector is investigated with a rise time of about 40 μs, which exceeds the response time of most GeSn (Ge)-related devices. In addition, this transfer process can be applied on various substrates, making it a versatile technology that can be used for various applications ranging from optoelectronics to large-area electronics. These results provide insightful guidance for the development of low-cost and high-speed SWIR photodetectors based on Sn-containing group IV low-dimensional structures.
Low-energy room-temperature optical switching in mixed-dimensionality nanoscale perovskite heterojunctions
Perovskite nanocrystals and SWCNTs join forces in optical synapses with attractive switching metrics and low-energy operation.
Hierarchical Hybrid Multifunctional Materials through Interface Engineering
This project focuses on the development of stimuli-responsive hybrid multifunctional materials. We place emphasis on the design, synthesis, structural characterization, evaluation of functional properties (electronic, thermal and optical) of several (1-x)Cu 2 Se/(x)WBGS hierarchical bulk composites between Cu 2 Se, a narrow band gap semiconductor (NBGS), with a range of wider band gap semiconductors (WBGS) such as CuMSe 2 (M = Al, Ga, In, Fe, Cr) and Cu 4 TiSe 4 . Cu2Se is a well-studied NBGS with excellent thermoelectric properties (high electrical conductivity, large thermopower, etc.) while CuMSe 2 and Cu 4 TiSe 4 are high performance solar absorber materials (large band gap, large absorption coefficient, etc.). Our primary objectives are (i) to demonstrate the ability to integrate dissimilar functional properties such as large optical absorption coefficient and high electronic conductivity, within (1-x)Cu 2 Se/(x)WBGS composite; and (ii) to establish the correlation between the hierarchical structural entanglement of Cu 2 Se with WBGS (CuMSe 2 or Cu 4 TiSe 4 ) phase, the interactions between native electronic defects within the coexisting phases in the resulting (1-x)Cu 2 Se/(x)WBGS bulk composites , and the impacts on their electronic conductivity, thermal transport and optical properties.
10-mu photometry of 25 stars from b8 to m7.
Twenty-five stars from b8 to m7 measured by photometer using germanium photoconductor
On vacuum UV study of solids Status report no. 7, Nov. 1 - Apr. 30, 1966
Electron emission, conductivity, and luminescence of selected solids under ultraviolet radiation
Evaporated and recrystallized CdS layers.
Evaporated and recrystallized CdS layers, discussing electron mobility, level distribution, capture cross section and techniques of measurement
GaAs Multiplexers for VLWIR Detector Readout Below 10 Kelvin
A multiplexer and buffer based on GaAs JFET technology is presented. This multiplexer operates normally from room temperature down to 4 Kelvin and is suitable for the readout of Very Long Wavelength Infrared Detectors that must be cooled to below 10 Kelvin.