Homogeneous SnF 2 ‐Induced Strain Modulation in Sn–Pb Perovskites for High‐Performance Monolithic All‐Perovskite Tandem Solar Cells

作者：Jinpei Wang, Wenxiu Dang, Yu Zhang, Chen Zhang, Zhiping Hu, Xiaoyan Zhang, Ye Tian, Kui Xu, Qingxun Guo, Lingfeng Chao, Jing Zhang, Yingdong Xia, Xingyu Gao, Zhelu Hu, Yonghua Chen · 发表于：Angewandte Chemie · 年份：2025 · DOI：10.1002/ange.202515733 · 被引用次数：3 · 研究领域：Perovskite Materials and Applications、TiO2 Photocatalysis and Solar Cells、Organic Electronics and Photovoltaics

Abstract Tin fluoride (SnF 2 ) serves as an indispensable antioxidant in Sn–Pb perovskite solar cells, playing a critical role in the development of efficient all‐perovskite tandem architectures. However, excessive SnF 2 often suffers from aggregation challenges, inevitably causing phase separation and tensile strain within the perovskite films, severely compromising device efficiency and stability. In this study, we report a precise regulation strategy by employing phenylethylammonium chloride (PEACl) to modulate the distribution of excess SnF 2 . The hydrogen bonding between PEACl and SnF 2 , coupled with steric hindrance effects, enables uniform dispersion of SnF 2 at grain boundaries, effectively suppressing SnF 2 phase segregation and promoting homogeneous crystallization of Sn–Pb perovskites. Moreover, it is revealed that the precise regulation of SnF 2 distribution through PEACl effectively releases local strain in perovskite thin films. Single‐junction Sn–Pb devices treated with the SnF 2 +PEACl demonstrate an exceptional power conversion efficiency (PCE) of 23.52%, substantially outperforming control devices at 20.83%. The optimized two‐terminal (2‐T) monolithic all‐perovskite tandem solar cells achieve a remarkable PCE of 28.89%. Notably, these tandem devices maintain over 80% of their initial efficiency after continuous operation at maximum power point under one‐sun illumination for 670 h, exhibiting excellent long‐term stability.