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

Journal Article · Fri Nov 15 04:00:00 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), Journal Name: J. Appl. Phys.; (United States) Vol. 58:10; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

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