Crystallization Improvement and Defect Passivation of CsPbI2Br Perovskite Solar Cells by Introducing Additive

The CsPbI2Br perovskite with a suitable bandgap demonstrates exceptional photothermal stability. Currently, the key factor for the commercialization of CsPbI2Br perovskite solar cells (PSCs) lies in enhancing their power conversion efficiency (PCE). In this study, we introduce a multifunctional additive of 4-chloroaniline (PCA) into n-i-p structured CsPbI2Br PSCs. After annealing, the crystallinity of the perovskite layer doped with PCA was significantly enhanced. Additionally, PCA existing in the perovskite layer effectively passivates defects through chemical coordination between amine and Pb2+, thereby further improving the device performance. Through effective management of crystallization and defect passivation, we observe a substantial increase in PCE from 13.44% to 16.15%. This research provides valuable insights for selecting efficient additives for inorganic PSCs.