Measurement of a long diffusion length in a GaAs film improved by metalorganic-chemical-vapor-deposition source purifications

Journal Article · Fri Nov 15 00:00:00 EST 1985 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.335592· OSTI ID:5202350

Partain, L D; Cohen, M J; Cape, J A; Fraas, L M; McLeod, P S; Dean, C S; Ransom, R A

The vacuum metalorganic-chemical-vapor-deposition (Vacuum MOCVD) process was combined with two source purifications to grow p-GaAs epitaxial films of high quality. Theoretical modeling of quantum yield spectra measured on a specially configured n/sup +/-p sample determined the minority-carrier electron diffusion length to be 10 ..mu..m to within a factor of 2 in the p layer. The p doping was reduced to the 5 x 10/sup 17/ cm/sup -3/ level to avoid suppression of the diffusion length by Auger recombination. Multiple vacuum sublimations of dicyclopentadienyl magnesium (CP/sub 2/Mg), the source of Mg for p doping, reduced the contamination by air and by cyclopentadiene (CP) by an order of magnitude. A dry ice/acetone cold trap was operated at slightly below 180-Torr pressure to reduce the water vapor content of arsine, used as the As source, from the hundreds of ppm down level down to the 2 ppm range. The vacuum growth process reduced residual gas contamination. These techniques were combined to grow a p on n GaAs solar cell with an efficiency of 24% at air mass 1.5 (AM1.5).

• Research Organization: Chevron Research Company, Richmond, California 94802-0627
• OSTI ID: 5202350
• Journal Information: J. Appl. Phys.; (United States), Vol. 58:10
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
CHEMICAL VAPOR DEPOSITION
PURIFICATION
GALLIUM ARSENIDE SOLAR CELLS
FABRICATION
PERFORMANCE
VAPOR DEPOSITED COATINGS
GALLIUM ARSENIDES
CHARGED-PARTICLE TRANSPORT
ACETONE
AIR
AUGER EFFECT
CHARGE CARRIERS
CONTAMINATION
CRYSTAL DOPING
DIFFUSION
EFFICIENCY
EXPERIMENTAL DATA
MAGNESIUM COMPOUNDS
ORGANOMETALLIC COMPOUNDS
RECOMBINATION
VACUUM SYSTEMS
VAPOR PHASE EPITAXY
ALKALINE EARTH METAL COMPOUNDS
ARSENIC COMPOUNDS
ARSENIDES
CHEMICAL COATING
COATINGS
DATA
DEPOSITION
DIRECT ENERGY CONVERTERS
EPITAXY
EQUIPMENT
FLUIDS
GALLIUM COMPOUNDS
GASES
INFORMATION
KETONES
NUMERICAL DATA
ORGANIC COMPOUNDS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PNICTIDES
RADIATION TRANSPORT
SOLAR CELLS
SOLAR EQUIPMENT
SURFACE COATING
140501* - Solar Energy Conversion- Photovoltaic Conversion