The commercialization of formamidinium‐based perovskite solar cells (PSCs), despite their certified power conversion efficiencies exceeding 27%, is significantly hindered by their intrinsic phase instability under ambient conditions, particularly in high humidity. Developing fabrication protocols that can directly produce high‐performance devices in air is therefore a critical research objective. Current strategies often struggle to simultaneously control crystallization kinetics and prevent environmental degradation during processing. In this work, we address this challenge through a synergistic materials and processing approach. We incorporate the hydrophobic ionic liquid BMIMPF 6 into the perovskite precursor and employ laser shock annealing to enable fabrication in high‐humidity air (~70% RH). The BMIMPF 6 additive functions by modifying crystallization kinetics and passivating defects during the film formation. The subsequent laser shock annealing induces rapid microstructural densification. This combined processing results in a pinhole‐free morphology with improved crystalline order and embedded ionic liquid molecules within the lattice. As a result, the champion devices (with PEAI) fabricated entirely in ambient air achieved a power conversion efficiency of 23.50% with negligible hysteresis and exhibited exceptional stability, maintaining 100% of their initial efficiency throughout 700 h of continuous operation, thereby validating the robustness of this approach for ambient‐air production of high‐performance PSCs.
Peng et al. (Fri,) studied this question.