Hetero-junction microcrystalline silicon solar cells with wide-gap p-μc-Si1−xOx:H layer

Preparation of p-type hydrogenated microcrystalline silicon oxide thin films (p-μc-Si_1-xO_x: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-Si_1-xO_x: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-Si_1-xO_x:H is effective to improve the open circuit voltage of the solar cells. We also confirmed that the open circuit voltage (V_oc) logarithmically increased with increasing the light intensity, and the enhancement of V_oc improved with increasing the band gap of p-layer. These results indicate that wide-gap p-μc-Si_1-xO_x:H is promising for use as window layer in hetero-junction μc-Si:H solar cells.