IMPROVEMENT OF THE SHORT-CIRCUIT CURRENT OF THIN-FILM POLYSILICON SOLAR CELLS USING PLASMA TEXTURING

摘要

Thin films of polycrystalline silicon are considered to be a cost-effective alternative for bulk silicon solar cells. Recently we found that using an amorphous silicon - crystalline silicon heterojunction emitter, open-circuit voltages well above 500 mV could be obtained. However efficiencies were still low due to a limited short-circuit current. In this paper we report on the beneficial influence of a short plasma texturing step on our devices. Results showed that plasma texturing should be optimized simultaneously with the layer structure, in particular with the thickness of the highly doped regions. Using a textured front side and a thin p~+ layer, we increased our highest efficiency from 5.9% to 7%. These light trapping results prove the high potential of our thin-film polysilicon devices.