Wang, Yanhao; Geng, Yirong; Hao, Hongwei; Ren, Wei; Zhang, Hai; Li, Jingjie; Zhang, Yongzhe; Wang, Jilei; Bao, Shaojuan; Wang, Hui; Zhang, Shan-Ting; Li, Dongdong

CELL REPORTS PHYSICAL SCIENCE

2024, 5, 2666-3864

Wang, Yanhao; Geng, Yirong; Hao, Hongwei; Ren, Wei; Zhang, Hai; Li, Jingjie; Zhang, Yongzhe; Wang, Jilei; Bao, Shaojuan; Wang, Hui; Zhang, Shan-Ting; Li, Dongdong

Effective surface passivation is pivotal for achieving high performance in crystalline silicon (c c- Si) solar cells. However, many passivation techniques in solar cells involve high temperatures and cost. Here, we report a low-cost and easy-to-implement sulfurization treatment as a surface passivation strategy. By treating p- type c- Si (p p- Si) wafers with (NH4)2S 4 ) 2 S solution, sulfur can be introduced onto the surface and passivate the dangling bonds by forming an Si-S bond. Sulfurization also contributes to a higher negative fixed charge at the p- Si/Al 2 O 3 interface and, thus, better field-effect passivation. Due to the improved passivation, sulfurization effectively enhances hole selectivity, evidenced by the substantially improved open-circuit voltage and efficiency of solar cells. Eventually, by employing sulfurization in hole-selective contacts, remarkable efficiencies of 19.85% and 22.01% are attained for NiOx- x- and MoOx-based x-based passivating contact c- Si solar cells, respectively. Our work highlights a promising sulfurization strategy to enhance surface passivation and hole selectivity for dopant-free c- Si solar cells.