A simplified process flow for silicon heterojunction interdigitated back contact solar cells: Using shadow masks and tunnel junctions

A novel process flow, which can allow the formation of interdigitated p- and n-type a-Si strips and corresponding transparent conductive oxide (TCO) and metal layers for silicon heterojunction interdigitated back contact (SHJ-IBC) solar cells using only a single alignment step and without using any resist patterning is presented. The flow is based on the deposition of a-Si, TCO and metal layers through a stack of shadow masks. Three variation of the flow are described. Several key process components to include a-Si deposition and H₂ plasma etch through the shadow mask are demonstrated and described.