Temporal Decoupling of Processing and Passivation: A Latent Passivator Activated by In Situ Hydrolysis for Efficient Perovskite Solar Cells

ABSTRACT In the fabrication of n‐i‐p structured perovskite solar cells (PSCs), the perovskite layer is usually annealed in a humid environment to obtain large‐sized grains. However, the uncontrollable crystallization of complex solution components and moisture‐induced degradation result in poor crystalline quality of the perovskite layer. In this work, a novel hydrolysis‐triggered intelligent passivation of inert precursor (HTIPIP) strategy is proposed. Specifically, the inert precursor 3‐(trifluoromethyl)phenylboronic acid pinacol ester (3‐CF 3 ‐PhBpin) in the perovskite solution is in situ hydrolyzed to 3‐(trifluoromethyl) phenylboronic acid (3‐CF 3 ‐PhB(OH) 2 ), which acts as a strong Lewis acid to precisely and on‐demand passivate the defects generated during the crystallization process, while the ‐CF 3 group simultaneously provides hydrophobic protection. This strategy converts the notorious water‐induced crystallization damage of perovskite films into a chemical reaction driving force for improving the crystallization quality. Therefore, the rigid and flexible n‐i‐p perovskite solar cells fabricated based on this strategy achieved power conversion efficiencies (PCE) of 26.25% and 24.80%, respectively, and also realized significant improvements in operational stability. This work elucidates a new molecular design paradigm of actively adapting to and intelligently utilizing the processing environment, which provides critical support for the ambient‐compatible manufacturing of large‐scale perovskite photovoltaics.