Thin film polycrystalline silicon solar cells. Quarterly report No. 1, 1 October-31 December 1978

Technical Report · Sun Jan 01 04:00:00 EST 1978

DOI:https://doi.org/10.2172/5324382· OSTI ID:5324382

Sarma, K. R.; Rice, M. J.

During this quarter, the Energy Beam deposition system was modified to obtain a deposition zone of uniform temperature. Parametric studies of silicon deposition are being conducted using this system employing a square cross-section reactor with SiHCl/sub 3/ as silicon source gas. In these experiments, large-area self-supporting silicon films with lengths up to 18'' were produced. As a long term solution to beam arcing problems, a rotating energy beam nozzle was designed, built and tested. Silicon deposition experiments using SiO/sub 2/ coated molybdenum indicated that SiO/sub 2/ acts as a good diffusion barrier and prevents the formation of MoSi/sub 2/; these films, however, would not separate from the substrate, so it appears that an MoSi/sub 2/ interface is necessary for shear separation. Energy Beam deposited silicon films were grain enhanced by the RTR technique. These silicon films, as grown, have exhibited unmeasurably low (by the SPV technique) minority carrier diffusion lengths, possibly due to a pervasive contamination during RTR growth. However, a gettering sequence involving PH/sub 3/ diffusion has been found to substantially improve the diffusion length of RTR processed CVD silicon films, and similar improvements can be expected in the energy beam films also, Diffusion lengths in excess of 100 ..mu..m were observed in the gettered CVD silicon films.

• Research Organization: Motorola, Inc., Phoenix, AZ (USA). Solar Energy Dept.
• OSTI ID: 5324382
• Report Number(s): DSE-2207-T2
• 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
CHARGE CARRIERS
CHEMICAL REACTORS
COATINGS
CRYSTAL GROWTH
CRYSTAL GROWTH METHODS
CRYSTAL STRUCTURE
CRYSTALS
DEPOSITION
DIFFUSION LENGTH
DIRECT ENERGY CONVERTERS
ELEMENTS
ENERGY BEAM DEPOSITION
ENERGY BEAM DEPOSITION FILMS
EQUIPMENT
FABRICATION
FILMS
GETTERING
IMPURITIES
MICROSTRUCTURE
NOZZLES
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
POLYCRYSTALS
RESEARCH PROGRAMS
RIBBON-TO-RIBBON METHOD
SEMIMETALS
SILICON
SILICON SOLAR CELLS
SOLAR CELLS
SOLAR EQUIPMENT
SURFACE COATING