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

The CsPbI 2 Br perovskite with a suitable bandgap demonstrates exceptional photothermal stability. Currently, the key factor for the commercialization of CsPbI 2 Br 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 CsPbI 2 Br 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 Pb 2+, 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.