Synergistic Bidirectional Crystallization for High‐Performance Perovskite Solar Cells

ABSTRACT Traditional n‐i‐p perovskite solar cells (PSCs) have achieved remarkable power conversion efficiencies exceeding 26%, yet their performance and stability remain critically bottlenecked by interfacial voids and detrimental trap states at the buried interface. These structural anomalies fundamentally originate from the conventional top‐down crystallization process, where a rapidly formed top crust induces a solvent blockade effect, trapping residual solvents that subsequently evaporate to leave detrimental buried voids. Here, we overcome this kinetic limitation via a synergistic bidirectional crystallization strategy, enabled by a dual‐functional molecular linker, diethyl phosphoramidate (DAPE). By strongly anchoring to the SnO 2 substrate and chemically bridging perovskite precursors, DAPE induces a synchronous bottom‐up growth front that complements the anti‐solvent‐induced top‐down crystallization. This kinetically reconstructed process maintains open solvent‐evasion channels, effectively eliminating the solvent blockade to yield a dense, void‐free interface. Consequently, the optimized devices exhibit relaxed residual stress and minimized non‐radiative recombination, achieving a champion power conversion efficiency of 26.25% with superior operational stability. Our work underscores the vital role of regulating crystallization kinetics to eliminate physical interfacial anomalies, offering useful insights for the further development of efficient n‐i‐p PSCs.