Development of Interdigitated Back Contact Silicon Heterojunction (IBC Si-HJ) Solar Cells

This study deals with the development and optimization of Interdigitated Back Contact (IBC) Silicon Heterojunction (Si-HJ) solar cells based on n-type crystalline silicon (c-Si) substrates. Both one-dimensional (1D) and 2D aspects of IBC Si-HJ cells are explored in this work. Rear Emitter (RE) Si-HJ cells are fabricated to study the influence of the emitter stack on 1D resistive losses. It is shown that the rear emitter stack has to be carefully designed to maintain a high surface passivation level without inducing series resistance (RSeries). On IBC Si-HJ structures, the influence of 2D features such as emitter contact fraction are confirmed both experimentally and by modeling. Using the screen printing technology, 25 cm2 IBC Si-HJ structures have been fabricated with an efficiency of 15.7%.