Tailored Multisite Rigid Conjugated Molecules to Anchor Perovskite for Comprehensive Management of Perovskite Crystallization and Defects

Abstract engineering has emerged as a promising approach to improve the stability and power conversion efficiency of perovskite solar cells (PSCs) by regulating the crystallization or defects. Conventional methods typically focus on a single functional group, leading to a deficiency in simultaneously addressing the above mentioned two aspects. Here, an innovative approach using (methylsulfonyl)phenyl)prop‐2‐en‐1‐amine hydroiodide (MSPPAI) is presented to concurrently and effectively modulate perovskite crystallization and defect passivation. The unique structure of MSPPAI, combining a rigid conjugated structure with multisite anchoring groups (─NH 2 and ─SO 2 ─), enables precise regulation through strong interaction with perovskite components. This interaction promotes the preferred (100) orientation of perovskite crystals, enhances the grain size, and thus improves the film quality. Meanwhile, the conjugated structure and approximate coplanarity further facilitate ordered crystallization and directional growth. Furthermore, by preventing volatile loss and coordinating with residual Pb 2+ , MSPPAI could effectively stabilize grain boundaries and surfaces to reduce defects and prevent degradation. Utilizing these mechanisms, the corresponding MSPPAI based devices achieves an efficiency of 25.54% and exhibits excellent stability that maintains 93% of its initial efficiency even after 1600 h under humid conditions. This molecular design strategy presents a novel approach for improving the efficiency and stability of PSCs.