Synthesis of silane and silicon in a nonequilibrium plasma jet. Final report

Technical Report · Sun Oct 01 00:00:00 EDT 1978

DOI:https://doi.org/10.2172/5868372· OSTI ID:5868372

Calcote, H. F.

The original objective of this program was to determine the feasibility of high volume, low-cost production of high purity silane or solar cell grade silicon using a nonequilibrium plasma jet. The emphasis was changed near the end of the program to determine the feasibility of preparing photovoltaic amorphous silicon films directly using this method. The nonequilibrium plasma jet is produced by partially dissociating hydrogen to hydrogen atoms in a 50 to 100 Torr glow discharge and expanding the H/H/sub 2/ mixture through a nozzle. A high flux density of hydrogen atoms is thus produced at concentrations of about 3 mol % with about 30% energy utilization efficiency. The jet is mixed with a second reactant and the reaction proceeds at a temperature of 400 to 600/sup 0/K to produce products. Yields of SiH/sub 4/, SiHCl/sub 3/, or SiH/sub 2/Cl/sub 2/ from SiCl/sub 4/ and SiHCl/sub 3/ were too low to be economically attractive. However, both amorphous and polycrystalline silicon films which strongly adhered to Pyrex, Vycor, aluminum, or carbon were prepared with either SiCl/sub 4/ or SiHCl/sub 3/ reactants. Preliminary doping experiments with PH/sub 3/ did not alter the electrical resistivity of these films. Strongly adhering films with SiH/sub 4/ reactant were more difficult to prepare; they were prepared by carefully cleaning the aluminum substrate, diluting the SiH/sub 4/ with about 90% argon, and forming the glow discharge between the mixing nozzle and the aluminum substrate. Doping such films with P by adding PH/sub 3/ reduced the electrical resistivity by two orders of magnitude. The nonequilibrium plasma jet should be further evaluated as a technique for producing high efficiency photovoltaic amorphous silicon films.

• Research Organization: Aerochem Research Labs., Inc., Princeton, NJ (USA)
• DOE Contract Number: NAS-7-100-954560
• OSTI ID: 5868372
• Report Number(s): DOE/JPL/954560-8
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
SILANES
SYNTHESIS
SILICON
CHEMICAL PREPARATION
ALUMINIUM
ARGON
CRYSTAL DOPING
ELECTRIC CONDUCTIVITY
FEASIBILITY STUDIES
FLUX DENSITY
GLOW DISCHARGES
HYDROGEN
NOZZLES
PHOSPHORUS HYDRIDES
PLASMA JETS
SILICON CHLORIDES
SILICON HALIDES
SUBSTRATES
CHLORIDES
CHLORINE COMPOUNDS
CRYOGENIC FLUIDS
ELECTRIC DISCHARGES
ELECTRICAL PROPERTIES
ELEMENTS
FLUIDS
HALIDES
HALOGEN COMPOUNDS
HYDRIDES
HYDROGEN COMPOUNDS
METALS
NONMETALS
PHOSPHORUS COMPOUNDS
PHYSICAL PROPERTIES
RARE GASES
SEMIMETALS
SILICON COMPOUNDS
140501* - Solar Energy Conversion- Photovoltaic Conversion