Electrodeposition of polycrystalline and amorphous silicon for photovoltaic applications. Final report, June 11, 1979-September 10, 1980

• Main Author: Rauh, R.D.
• Language: unknown
• Published: 2022
• Subjects: 14 SOLAR ENERGY; SILICON; ELECTROPLATING; AMORPHOUS STATE; AUGER ELECTRON SPECTROSCOPY; CARBONIC ACID ESTERS; INFRARED SPECTRA; MOLTEN SALTS; POLYCRYSTALS; POTASSIUM FLUORIDES; PRECURSOR; SILICON FLUORIDES; SODIUM FLUORIDES; VOLTAMETRY; ALKALI METAL COMPOUNDS; CRYSTALS; DEPOSITION; ELECTRODEPOSITION; ELECTROLYSIS; ELECTRON SPECTROSCOPY; ELEMENTS; ESTERS; FLUORIDES; FLUORINE COMPOUNDS; HALIDES; HALOGEN COMPOUNDS; LYSIS; ORGANIC COMPOUNDS; PLATING; POTASSIUM COMPOUNDS; SALTS; SEMIMETALS; SILICON COMPOUNDS; SODIUM COMPOUNDS; SPECTRA; SPECTROSCOPY; SURFACE COATING; Carbonic acid
• Online Access: http://www.osti.gov/servlets/purl/6168977; https://www.osti.gov/biblio/6168977; https://doi.org/10.2172/6168977

Silicon was electrodeposited on metal substrates using two markedly different conditions. Polycrystalline deposits were obtained from K/sub 2/SiF/sub 6/ dissolved in high temperature (> 700/sup 0/C) molten fluoride salts. The deposits produced at temperatures below 80/sup 0/C from organo- and halo-silanes as silicon precursors in propylene carbonate electrolytes had an amorphous structure. Because the technology of electroplating silicon is largely undeveloped, a major emphasis was given to the electrochemical characterization of the plating baths and the relationship between the deposition conditions and the resulting deposits. The results with FLINAK (LiF (46.5%), KF (42.0%) and NaF (11.5%)) and the binary mixture LiF (50%) : KF (50%) as the molten salts for Si deposition were comparable. Cyclic voltammetry (CV) using a three-electrode configuration was done on the melts before and after addition of the silicon precursor. The amorphous silicon was deposited from propylene carbonate which had been dried over alumina. The best supporting electrolytes were tetrabutylammonium perchlorate and tetrafluoroborate. The silicon precursors investigated were SiHCl/sub 3/, SiHBr/sub 3/, SiCl/sub 4/, (ClC/sub 3/H/sub 6/)SiCl/sub 3/, Si(OEt)/sub 4/ and (CH/sub 3/)/sub 3/SiCl. Information on the chemical composition of the films was obtained from IR and Auger spectroscopy.