14.31 % Power Conversion Efficiency of Sn‐Based Perovskite Solar Cells via Efficient Reduction of Sn 4+

作者：Liang Wang, Qingqing Miao, Dandan Wang, Mengmeng Chen, Hua̅n Bì, Jiaqi Liu, Ajay Kumar Baranwal, Gaurav Kapil, Yoshitaka Sanehira, Takeshi Kitamura, Tingli Ma, Zheng Zhang, Qing Shen, Shuzi Hayase · 发表于：Angewandte Chemie International Edition · 年份：2023 · DOI：10.1002/anie.202307228 · 被引用次数：66 · 研究领域：Perovskite Materials and Applications、Conducting polymers and applications、Chalcogenide Semiconductor Thin Films

Abstract The photoelectric properties of nontoxic Sn‐based perovskite make it a promising alternative to toxic Pb‐based perovskite. It has superior photovoltaic performance in comparison to other Pb‐free counterparts. The facile oxidation of Sn 2+ to Sn 4+ presents a notable obstacle in the advancement of perovskite solar cells that utilize Sn, as it adversely affects their stability and performance. The study revealed the presence of a Sn 4+ concentration on both the upper and lower surfaces of the perovskite layer. This discovery led to the adoption of a bi‐interface optimization approach. A thin layer of Sn metal was inserted at the two surfaces of the perovskite layer. The implementation of this intervention yielded a significant decrease in the levels of Sn 4+ and trap densities. The power conversion efficiency of the device was achieved at 14.31 % through the optimization of carrier transportation. The device exhibited operational and long‐term stability.