Thin films of silicon on low-cost substrates. Annual report, 1 July 1976-30 June 1977

Technical Report · Sat Jan 01 04:00:00 EST 1977

OSTI ID:6466634

Baghdadi, A; Gurtler, R W; Sarma, K R; Cota, M

The objective of the contract is to develop a method for high rate, low cost production of polycrystalline silicon films, using Energy Beam deposition, for use in fabricating terrestrial solar cells. The design and construction of the necessary facilities for Energy Beam deposition were completed. They included two deposition chambers and a suitable gas handling system. Several candidate temporary substrate techniques and materials were identified and evaluated. The thermal expansion mismatch technique employing tungsten and molybdenum substrates was found to be a reliable and efficient method of producing self-supporting silicon films. Energy Beam plasma characterization was performed. Grain size enhancement experiments by the RTR crystal growth technique were conducted using both temporary and permanent substrate methods. Considerable enhancement of grain size was obtained with the temporary substrate method. Some improvements in grain size were also observed with the permanent substrate methods. The effects of various parameters on Energy Beam deposition were investigated. Substrate temperatures were measured as a function of rf power, nozzle position and composition, and flow rate of the plasma gases. Rough calculations, based on the enthalpy of the plasma gases and substrate heat capacity, indicated that convective heat transfer from the plasma is mainly responsible for substrate heating. Silicon deposition experiments were conducted using the source gases SiH/sub 4/, SiHCl/sub 3/ and SiCl/sub 4/.

• Research Organization: Motorola, Inc., Phoenix, AZ (USA). Solar Energy Dept.
• DOE Contract Number: AC03-76ET20410
• OSTI ID: 6466634
• Report Number(s): DOE/ET/20410-T3
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140501* -- Solar Energy Conversion-- Photovoltaic Conversion
CHEMICAL REACTORS
CHLORIDES
CHLORINE COMPOUNDS
CONSTRUCTION
CONVECTION
CRYSTAL GROWTH METHODS
CRYSTAL STRUCTURE
CRYSTALS
DEPOSITION
DESIGN
ELEMENTS
ENERGY BEAM DEPOSITION
EXPANSION
GRAIN SIZE
HALIDES
HALOGEN COMPOUNDS
HYDRIDES
HYDROGEN COMPOUNDS
METALS
MICROSTRUCTURE
MOLYBDENUM
PARAMETRIC ANALYSIS
POLYCRYSTALS
REFRACTORY METALS
RIBBON-TO-RIBBON METHOD
SEMIMETALS
SILANES
SILICON
SILICON CHLORIDES
SILICON COMPOUNDS
SIZE
SUBSTRATES
SURFACE COATING
THERMAL EXPANSION
TRANSITION ELEMENTS
TUNGSTEN