Silicon materials task of the low cost solar array project (Phase III): effect of impurities and processing on silicon solar cells. Fourteenth quarterly report, January-March 1979

Technical Report · Sun Apr 01 04:00:00 EST 1979

DOI:https://doi.org/10.2172/5858438· OSTI ID:5858438

Hopkins, R H; Davis, J R; Blais, P D; Rohatgi, A; Campbell, R B; Rai-Choudhury, P; Stapleton, R E; Mollenkopf, H C; McCormick, J R

The objective of this program is to determine how various processes, impurities, and impurity-process interactions affect the properties of silicon and the performance of terrestrial solar cells made from silicon. The data provide a basis for cost-benefit analysis to the producers and users of Solar Grade Silicon. The Phase III effort encompasses five major topics: (1) examination of the interaction of impurities with processing treatments, (2) generation of a data base and modeling of impurity effects in n-base solar cells, (3) extension of previous p-base studies to include impurities likely to be introduced during silicon production, refining or crystal growth, (4) a consideration of the potential impact of anisotropic (nonuniform) impurity distribution in large Czochralski and ribbon solar cells and, (5) a preliminary investigation of the permanence of impurity effects in silicon solar cells. During this quarter (1) the mechanisms responsible for impurity deactivation during high temperature gettering treatments was examined in detail, (2) the sead to tang and center to edge variation in Czechralski ingot properties for commercial-size ingots doped with Ti and Mn was evaluated, and (3) aging effects in solar cells doped with Ti or Mo were assessed. Also, an analysis of impurity effects on crystal structure breakdown, and the monitoring of ingot lifetimes by photoconductive decay lifetime measurement before and after processing were continued. The highlights of this work are described. (WHK)

• Research Organization: Westinghouse Research and Development Center, Pittsburgh, PA (USA)
• DOE Contract Number: NAS-7-100-954331
• OSTI ID: 5858438
• Report Number(s): DOE/JPL/954331-6
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140501* -- Solar Energy Conversion-- Photovoltaic Conversion
AGING
CARRIER LIFETIME
CRYSTAL GROWTH
CRYSTALS
CZOCHRALSKI METHOD
DIRECT ENERGY CONVERTERS
DISTRIBUTION
ELEMENTS
GETTERING
IMPURITIES
LIFETIME
METALS
MOLYBDENUM
MONOCRYSTALS
PERFORMANCE
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PROCESSING
RECOMBINATION
REFRACTORY METALS
RESEARCH PROGRAMS
SILICON SOLAR CELLS
SOLAR CELLS
SPATIAL DISTRIBUTION
TITANIUM
TRANSITION ELEMENTS