Thin films of gallium arsenide on low-cost substrates. Quarterly project report No. 2, December 1, 1976--February 28, 1977
The objective of this program is to conduct intensive studies concerning thin films of gallium arsenide on low cost substrates as an initial step for the fabrication of low cost thin film solar cells of relatively high efficiency and long life. Efforts during this quarter have been directed to the testing of gallium arsenide deposition systems, the deposition and characterization of gallium arsenide films of single crystalline gallium arsenide and germanium substrates, the preparation of tungsten/graphite and germanium (recrystallized)/tungsten/graphite substrates, and the deposition and characterization of gallium arsenide films on these substrates. Homoepitaxial gallium arsenide films have net electron concentration and Hall mobility of 10/sup 14/cm/sup -3/ and 6500 cm/sup 2//V-sec, respectively, at room temperatures, indicating the satisfactory performance of the gallium arsenide deposition systems. Heteroepitaxial gallium arsenide films deposited on germanium substrates without intentional doping have net electron concentration and Hall mobility of 7 x 10/sup 17/cm/sup -3/ and 1700 cm/sup 2//V-sec, respectively, due to auto-doping from the substrate. Germanium films deposited on tungsten/graphite substrate have been recrystallized by unidirectional solidification. Recrystallized germanium has a dendritic structure with strong (111) preferred orientation. Gallium arsenide films deposited on recrystallized germanium substrates have a similar structure. Gallium arsenide films deposited on tungsten/graphite substrates consist of small crystallites, up to 15 ..mu..m in dimension, and the control of dopant concentration appears to be difficult.
- Research Organization:
- Southern Methodist Univ., Dallas, TX (USA)
- OSTI ID:
- 7219198
- Report Number(s):
- SAN-1284-2
- Country of Publication:
- United States
- Language:
- English
Similar Records
Thin films of gallium arsenide on low-cost substrates. Quarterly project report No. 3, March 1, 1977-May 31, 1977
Thin films of gallium arsenide on low-cost substrates. Annual report, September 1, 1976-August 31, 1977
Related Subjects
140501* -- Solar Energy Conversion-- Photovoltaic Conversion
ARSENIC COMPOUNDS
ARSENIDES
CARBON
CHEMICAL COATING
CHEMICAL VAPOR DEPOSITION
CRYSTAL GROWTH
DEPOSITION
DIRECT ENERGY CONVERTERS
ELEMENTS
FABRICATION
FILMS
GALLIUM ARSENIDE SOLAR CELLS
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
GERMANIUM
GRAPHITE
METALS
NONMETALS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PNICTIDES
REFRACTORY METALS
SOLAR CELLS
SUBSTRATES
SURFACE COATING
TRANSITION ELEMENTS
TUNGSTEN