Application of hydrogenated amorphous silicon oxide layers to c-Si heterojunction solar cells

Abstract

Wide-gap hydrogenated amorphous silicon oxide (a-SiO:H), fabricated by plasma process using SiH4 and CO2 gas mixture, has been applied to crystalline silicon (c-Si) heterojunction solar cells. It has been demonstrated that incorporation of an a-SiO:H p layer, instead of a hydrogenated amorphous silicon (a-Si:H) p layer, improves the conversion efficiency slightly. Moreover, when an a-SiO:H i layer is formed on the c-Si substrate, Si epitaxial growth that occurs at an a-Si:H∕c-Si heterointerface at high deposition temperatures can be prevented entirely. Accordingly, high-efficiency solar cells are fabricated more easily by applying a-SiO:H p-i layers to n-type c-Si heterojunction solar cells.