Reverse bias and heat treatment to improve performance of a-Si solar cells

Amorphous silicon solar cells deposited on tin oxide coated glass with an amorphous silicon carbide p+ front contact layer were subjected to a reverse potential bias while at elevated temperatures. The bias-anneal treatment improved measured values of open circuit voltage, fill factor, and overall efficiency. The treatment increases efficiency by as much as 18%. The improvement in cell performance appears to be related to an increase in the μτ product and possibly an increase in the ionized dopant concentration of one or both contact layers.