Electrodeposition of Silicon from Solutions of Silicon Halides in Aprotic Solvents

Amorphous silicon has been electrodeposited from nonaqueous baths using as the silicon source. A typical bath composition was in propylene carbonate containing 0.1M tetrabutyl ammonium chloride as the supporting electrolyte. Deposits were made potentiostatically at around −2.5V vs. Pt reference at temperatures 35°–145°C under an argon atmosphere. A variety of materials including Pt, Ti, Ti‐6Al‐4V alloy, n‐Si, and indium‐tin oxide coated fused silica were used for the substrate. The as‐deposited silicon contains some hydrogen bonded as or . The quality and hydrogen content of the deposits are controllable by selecting the proper bath composition and operating temperature. The electrodeposition process offers an inexpensive route for producing α‐Si films for possible solar cell applications.