Improvement of bulk and epitaxial III-V semiconductors for solar cells by creation of denuded recombination zones

Technical Report · Thu Nov 01 04:00:00 EST 1990

OSTI ID:6343733

Wong, D; Kim, H K; Li, A-Z; Schlesinger, T E; Milnes, A G ^[1]

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1. Carnegie-Mellon Univ., Pittsburgh, PA (USA)

Increases in hole diffusion lengths of up to a factor of three were obtained in commercially grown liquid encapsulated Czochralski (Te-doped) and Si-doped horizontal Bridgman GaAs. This was achieved by application of a technique involving proximity annealing of the material in sealed silica ampoules. The short wavelength photoresponse of the cells was also enhanced. This was achieved by passivation of the surfaces of the cells with a simple chemical treatment using ammonium sulphide. Defect studies with deep level transient spectroscopy and photoluminescence revealed that the dominant recombination center in the material studied is a hole trap we have termed HCX (E{sub v}+0.29 eV). This is believed to be a native defect, perhaps associated with excess arsenic. Defect suppression was achieved in molecular beam epitaxial films by isoelectronic doping (with In and Sb). It was also shown that the defect structure in the films was affected by the choice of growth parameters such as growth rate and temperature.

• Research Organization: Solar Energy Research Inst., Golden, CO (USA); Carnegie-Mellon Univ., Pittsburgh, PA (USA)
• Sponsoring Organization: DOE/CE
• DOE Contract Number: AC02-83CH10093
• OSTI ID: 6343733
• Report Number(s): SERI/TP-211-3990; ON: DE90000387
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140501* -- Solar Energy Conversion-- Photovoltaic Conversion
36 MATERIALS SCIENCE
360601 -- Other Materials-- Preparation & Manufacture
360602 -- Other Materials-- Structure & Phase Studies
ARSENIC COMPOUNDS
ARSENIDES
CRYSTAL DEFECTS
CRYSTAL GROWTH
CRYSTAL STRUCTURE
DIRECT ENERGY CONVERTERS
DOCUMENT TYPES
EPITAXY
EQUIPMENT
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
LUMINESCENCE
MATERIALS
MODIFICATIONS
MOLECULAR BEAM EPITAXY
PERFORMANCE
PHOTOELECTRIC CELLS
PHOTOLUMINESCENCE
PHOTOVOLTAIC CELLS
PNICTIDES
PROGRESS REPORT
RECOMBINATION
SEMICONDUCTOR MATERIALS
SOLAR CELLS
SOLAR EQUIPMENT
SPECTROSCOPY