24.96%‐Efficiency FACsPbI<sub>3</sub> Perovskite Solar Cells Enabled by an Asymmetric 1,3‐Thiazole‐2,4‐Diammonium
Hui Zhou, Lu Yang, Yuwei Duan, Meizi Wu, Yong Li, Dongfang Xu, Hong Zou, Jungang Wang, Shaomin Yang, Zhike Liu
Abstract
Abstract Surmounting complicated defects at the electron transport layer (ETL) and perovskite interface plays a non‐trivial role in improving efficiency and stability of perovskite solar cells (PSCs). Herein, an asymmetric interface modification strategy (AIMS) is developed to passivate the defects from both a SnO 2 ETL and the perovskite buried surface via incorporating 1,3‐thiazole‐2,4‐diammonium (TDA) into the SnO 2 /perovskite interface. Detailed experimental and calculated results demonstrate that N3 (the nitrogen atom bonding to the imine) in the TDA preferentially cures the free hydroxyl (OH), oxygen vacancy ( V O ), and the Sn‐related defects on the SnO 2 surface, while N1 (the nitrogen atom bonding to the vinyl) is more inclined to passivate the Pb 2+ and I − related defects at the perovskite buried surface. As a result, the TDA‐modified FACsPbI 3 PSC yields a champion power conversion efficiency (PCE) of 24.96% with a gratifying open‐circuit voltage ( V oc ) of 1.20 V. In addition, the optimized PSCs exhibit charming air‐operational stability with the unencapsulated device sustaining 97.04% of its initial PCE after storage in air conditions for 1400 h. The encapsulated device maintains 90.21% of its initial PCE after maximum power point tracking for 500 h.