Component Distribution Regulation in Sn‐Pb Perovskite Solar Cells through Selective Molecular Interaction
Wenxiao Zhang, Haobo Yuan, Xiaodong Li, Xuemin Guo, Chunyan Lu, Acan Liu, Hui Ying Yang, Lin Xu, Xueliang Shi, Zhiwei Fang, Hai‐Bo Yang, Ya Cheng, Junfeng Fang
Abstract
Abstract Tin‐lead (Sn‐Pb) perovskite solar cells (PSCs) with near‐ideal bandgap still lag behind the pure lead PSCs. Disordered heterojunctions caused by inhomogeneous Sn/Pb ratio in the binary perovskite film induce large recombination loss. Here, an Sn‐Pb perovskite film is reported with homogeneous component and energy distribution by introducing hydrazine sulfate (HS) in Sn perovskite precursor. HS can form hydrogen bond network and coordinate with FASnI 3 thus no longer bond with Pb 2+ , which reduces the crystallization rate of tin perovskite to the level of lead analog. The strong bonding between SO 4 2− and Sn 2+ can also suppress its oxidation. As a result, the Sn‐Pb PSCs with HS exhibit a significantly improved V OC of 0.91 V along with a high efficiency of 23.17%. Meanwhile, the hydrogen bond interaction network, strong bonding between Sn 2+ and sulfate ion also improve the thermal, storage, and air stability of resulting devices.