Surface passivation is crucial for high-performance perovskite solar cells (PSCs). This study introduces a binary and synergistic post-treatment (BSPT) method using 4-tert-butyl-benzylammonium iodide and phenylpropylammonium iodide to enhance the passivation layer. The BSPT layer shows improved crystallinity, molecular packing, and energy band alignment, facilitating hole extraction and transfer. This led to a record-certified quasi-steady power conversion efficiency of 26.0% in PSCs, maintaining 81% of initial efficiency after 450 hours.

Zihan Qu, Yang Zhao, Fei Ma, Le Mei, Xian-Kai Chen, Haitao Zhou, Xinbo Chu, Yingguo Yang, Qi Jiang, Xingwang Zhang, Jingbi You