Production-Scale Electrodeposited Silicon Solar Cells: Issues to be Solved for Continous Manufacture

Fluorosilicic acid is a viable low-cost source of silicon for use in non-aqueous solvents for the electrodeposition of thin silicon layers on continuous plastic film. The acid is converted to an organic salt and purified by extraction. Sealed plastic electrolytic cells purged with N ₂ gas preserve <10ppm of O₂ and H₂O during deposition. An unsubmerged liquid jet provides for deposition rates suitable for large-scale production. Plastic film 125mm in width was used as a continuous web for production-scale demonstration. Monolithic crystalline cells with amorphous top cells demonstrated conversion efficiencies as high as 17%. Issues of continuous deposition and process control require further refinement in order to demonstrate consistent web efficiency