Surface Passivation for Silicon Heterojunction Solar Cells

Abstract

Silicon heterojunction solar cells (SHJ) are currently one of the most promising solar cell technologies in the world. The SHJ solar cell is based on a crystalline silicon (c-Si) wafer, passivated on both sides with a thin intrinsic hydrogenated amorphous silicon (a-Si:H) layer. Subsequently, p-type and n-type doped layers are deposited on the passivated wafer as the emitter and the back surface field of the solar cell. The first study of the a-Si:H/c-Si heterojunction for photovoltaic application was more than 40 years ago. During these years the SHJ solar cell technology has been investigated extensively, approaching the theoretical efficiency limit of single junction silicon solar cells. Although SHJ solar cell technology has been extensively studied and has demonstrated such a good performance, there are still aspects of the device operation not well understood. This thesis discusses certain aspects of SHJ solar cells and has a main focus on the surface passivation of the c-Si wafer. In this way it aims to contribute to the understanding of SHJ solar cell fabrication and operation, helping to improve the SHJ solar cell performance.