Tailoring Crystal Growth Regulation and Dual Passivation for Air‐Processed Efficient Perovskite Solar Cells

Abstract Hybrid metal halide perovskite solar cells (PSCs) are emerging as highly competitive next‐generation photovoltaics due to their excellent performance and low production cost. However, the construction of high‐efficiency PSCs typically requires an inert nitrogen environment within a glove box, inadvertently increasing manufacturing costs and hindering the transition from lab‐scale to industrial‐scale production. In this work, an air ambient fabrication of pure α‐phase FAPbI 3 PSCs with high‐efficiency and stability, utilizing a dual‐functional engineering strategy assisted by 3‐Guanidinopropionicacid (3‐GuA) is reported. 3‐GuA assists in managing excess PbI 2 and promotes the formation of high‐quality FAPbI 3 films via intermolecular exchange. Simultaneously, the existence of 3‐GuA minimizes the defects and stabilizes the resulting perovskite films. As a result, the ambient‐air fabricated PSCs achieve a power conversion efficiency (PCE) of 24.2% with negligible hysteresis and excellent stability. Additionally, these devices demonstrate superior reproducibility, offering valuable guidance for future advancements in this technology.