Disclosing Crystallization Kinetics for Efficient and Stable Perovskite Solar Cells

Abstract Perovskite solar cells (PSCs) have demonstrated huge commercial relevance as their power conversion efficiencies (PCEs) are capable of competing with conventional silicon‐based solar cells. The device performance greatly relies on the perovskite film quality with respect to perovskite crystallization and defect passivation. In this work, conjugated alkyl‐amine 3‐phenyl‐2‐propen‐1‐amine iodide (PPAI) is used to modulate the crystallization process of perovskite film. The related crystallization dynamics reveal that the PPAI additives result in homogeneous nucleation and growth of perovskite crystals, avoiding composition heterogeneity along the film normal. Moreover, the PPAI‐induced surface modification further reduces the defect density and thereby the non‐radiative recombination. As a result, the PSCs exhibit a champion PCE of 25.63% with the crystallization regulation and surface treatment. Furthermore, the device demonstrates exceptional operational stability, maintaining 92.77% of its initial performance after aging at 85 °C and 85 RH without encapsulation for 800 h, along with superior resistance to light‐induced degradation compared to conventional architectures.