Interface study of polycrystalline semiconductor-insulator-semiconductor (SIS) solar cells: Indium tin oxide on polysilicon

Improved understanding of performance limitations has led to considerably increased efficiency and reproducibility of ITO/polysilicon SIS solar cells. AM1 efficiencies as high as 12.2% (total area > 10 cm²) have been obtained on Wacker polysilicon. This paper discusses fabrication and characterization of ITO SIS solar cells on silicon-on-ceramic and Ribbon silicon substrates. Similar results have been observed for other polysilicon materials. These results represent the highest efficiencies reported for MIS/SIS solar cells. The key steps in the fabrication which led to these results are chemical etching of the polysilicon substrate and hydrogen passivation of the silicon surface and grain boundaries. Preliminary stability studies of these devices have shown no observable degradation. This paper addresses these results in terms of the interface properties of ITO/polysilicon structures.