Recent progress in indium tin oxide/polysilicon semiconductor-insulator-semiconductor (SIS) solar cells

With process optimization, proper substrate surface preparation of the polysilicon, and hydrogen passivation, high efficiencies have been achieved for large area indium tin oxide/polysilicon semiconductor-insulator-semiconductor (SIS) solar cells fabricated by ion beam sputtering method. The results are competative to the best diffused p-n junction Wacker polysilicon solar cells. Comparative evaluation of devices fabricated on Wacker and Monsanto polysilicon substrates show that the large number of defects and small grain size in Monsanto material are responsible for lower photovoltaic output. Preliminary data indicates that hydrogen is passivating defects mostly at the semiconductor-insulator interface with small or no change in the bulk transport properties.