Effect of p-μc-Si1−xOx:H layer on performance of hetero-junction microcrystalline silicon solar cells under light concentration

Preparation of p-type hydrogenated microcrystalline silicon oxide thin films (p-μc-Si1−xOx:H) by 13.56 MHz RF-PECVD method for use as a p-layer of hetero-junction μc-Si:H solar cells is presented. We investigated effects of wide-gap p-μc-Si1−xOx:H layer on the performance of hetero-junction μc-Si:H solar cells under various light intensity. We observed that a wide-gap p-μc-Si1−xOx:H was effective in improving the open-circuit voltage (Voc) of the solar cells. We also confirmed that the Voc logarithmically increased with increasing light intensity, and the enhancement of Voc became larger with increasing band gap of p-layer. These results indicate that wide-gap p-μc-Si1−xOx:H is a promising material for use as window layer in hetero-junction μc-Si:H solar cells.

► We have optimized p-μc-Si1−xOx:H films for hetero-junction μc-Si:H solar cells. ► Wide-gap p-μc-Si1−xOx:H was effective in improving the Voc of the solar cells. ► Wide-gap p-μc-Si1−xOx:H film can improve the performance of solar cells. ► Wide-gap p-layer is beneficial for 1 sun, and in higher light concentration.