Thin-film microcrystalline silicon solar cells: 11.9% efficiency and beyond

High-efficiency thin-film hydrogenated microcrystalline silicon solar cells (mu c-Si: H) were developed using a periodically textured substrate at a relatively high growth rate of similar to 1nm s(-1). A record efficiency of 11.9% was independently confirmed in a mu c-Si: H cell with an absorber thickness of approximately 2 mu m. An improvement in fill factor contributed largely to realizing the record efficiency. The potential for further efficiency improvements was examined on the basis of suns-VOC measurement, indicating that an efficiency of 12.5% is practically achievable. (C) 2018 The Japan Society of Applied Physics