Fully Ion-Implanted IBC Silicon Solar Cell with Gap Structure between Emitter and BSF by Self-Aligned Process

35th European Photovoltaic Solar Energy Conference and Exhibition; 624-627
We propose a fully implanted interdigitated back contact (IBC) silicon solar cell with a gap structure between the emitter and back surface field (BSF) fabricated using a self-aligned process with a single photolithography step. Boron was implanted on the entire rear side. After post-implantation annealing, the oxide layer was grown on the front and rear sides of the silicon wafer. The BSF region was patterned on the rear oxide layer via photolithography. A hollow structure with an overhang of the oxide layer was formed at the boundary between the emitter and BSF during the removal of the oxide and boron-implanted layer on the BSF region via reactive-ion etching and wet chemical etching. The overhanging oxide layer became the mask for subsequent phosphorus implantation on the BSF region.