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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.
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Abstracts, bibliographic data, oral presentations, and published papers on (1) Diffusion of Sulfur in Gallium Phosphide and Gallium Arsenide, and (2) Properties of Gallium Phosphide Schottky Barrier Rectifiers for Use at High Temperature are presented.
Radiotracer technique for sulfur diffusion in gallium phosphide and arsenide as function of temperature and pressure
Gallium phosphide (GaP) energy converters may be successfully deployed to provide new mission capabilities for spacecraft. Betavoltaic power supplies based on the conversion of tritium beta decay to electricity using GaP energy converters can supply long term low-level power with high reliability. High temperature solar cells, also based on GaP, can be used in inward-bound missions greatly reducing the need for thermal dissipation. Results are presented for GaP direct conversion devices powered by Ni-63 and compared to the conversion of light emitted by tritiarated phosphors. Leakage currents as low as 1.2 x 10(exp -17) A/sq cm have been measured and the temperature dependence of the reverse saturation current is found to have ideal behavior. Temperature dependent IV, QE, R(sub sh), and V(sub oc) results are also presented. These data are used to predict the high-temperature solar cell and betacell performance of GaP devices and suggest appropriate applications for the deployment of this technology.
Photoelectrical and optical properties of gallium phosphide
Design and fabrication of gallium phosphide rectifiers
Chemical, electrical, and optical properties of cobalt as gallium phosphide impurity
Absorption spectra of divalent iron in transition group elements and gallium phosphide
Extrinsic and intrinsic epitaxially deposited single crystal gallium phosphide solar cells, noting conversion efficiencies
Metallurgical, electrical, and optical properties of gallium phosphide
Metallurgical, electrical, and optical properties of gallium phosphide
Metallurgical, electrical, and optical properties of gallium phosphide systems
Single crystal gallium phosphide solar cells
Metallurgical, electrical, and optical properties of gallium phosphide
Betavoltaic power supplies based on gallium phosphide can supply long term low-level power with high reliability. Results are presented for GaP devices powered by Ni-63 and tritiarated phosphors. Leakage currents as low as 1.2 x 10(exp -17) A/cm(exp 2) have been measured and the temperature dependence of the reverse saturation current is found to have ideal behavior. A small demonstration system has been assembled that generates and stores enough electricity to light up an LED.
Metallurgical, optical, and electrical properties of gallium arsenide and gallium phosphide, and imperfections and donor impurities in GaP
Studies of metallurgical, electrical, and optical properties of gallium phosphide
Photoconductivity, solubility, diffusion and electric properties of doped and undoped gallium phosphide crystals
The unique properties of single-junction gallium phosphide devices incorporating both red and green radiative recombination centers were investigated in application to the fabrication of monolithic 5 x 7 displays capable of displaying symbolic and alphanumeric information in a multicolor format. A number of potentially suitable material preparation techniques were evaluated in terms of both material properties and device performance. Optimum results were obtained for double liquid-phase-epitaxial process in which an open-tube dipping technique was used for n-layer growth and a sealed tipping procedure for subsequent p-layer growth. It was demonstrated that to prepare devices exhibiting a satisfactory range of dominant wavelengths which can be perceived as distinct emission colors extending from the red through green region of the visible spectrum involves a compromise between the material properties necessary for efficient red emission and those considered optimum for efficient green emission.