A customized symmetric passivator to improve the efficiency and stability of inorganic CsPbI2Br perovskite solar cells

Defects in third-generation perovskite-based solar cells are mainly due to the weak interconnections in their constituent structure and insufficient resistance to environmental factors. This often results in physical instability and device failure. Therefore, developing an effective interface acting as a protective barrier and a connector is vital. Herein, we present palladium acetate succinimide (PAS) as a newly synthesized interface that significantly improves the performance of CsPbI2Br solar cells. Incorporating PAS into the perovskite structure significantly enhances charge transfer and reduces ion recombination. The optimized PSCs reached a high-power conversion efficiency (PCE) of 14.24 %, and an open-circuit voltage (VOC) of 1.301 V. Through the usage of a wide variety of experimental methodologies and also molecular dynamics simulations, the interaction of PAS and the perovskite material CsPbI2Br was fully understood, and it was found that PAS can stabilize the undercoordinated Pb2+ sites and enhance the crystallinity of the perovskite layer. The study demonstrated that PAS is not only a shallow trap passivator but also a way to increase connectivity between the perovskite and the electron transport layer (ETL), thus bettering device performance.