Vacuum Flash Evaporation‐Assisted Processing in Perovskite Photovoltaics

Perovskite solar cells (PSCs) have emerged as a leading next‐generation photovoltaic technology owing to their high‐power conversion efficiency, low fabrication cost, and solution processability. However, the performance and scalability of PSCs are critically limited by challenges in achieving high‐quality, uniform, and defect‐controlled perovskite films. Vacuum flash evaporation (VFE)‐assisted processing has recently attracted significant attention as an effective strategy to regulate film formation by rapidly extracting solvents under low‐pressure conditions, thereby inducing instantaneous supersaturation and uniform nucleation. This review provides a comprehensive overview of the development, fundamental principles, and classifications of this technique, with emphasis on its thermodynamic and kinetic mechanisms, intermediate‐phase regulation, and process parameter optimization. The impacts of VFE processing on film microstructure, including grain growth, crystallographic orientation, defect suppression, carrier dynamics, and ion migration, are systematically discussed. Furthermore, its applications in single‐junction and tandem devices are highlighted. Finally, key challenges and prospects toward scalable manufacturing and industrialization are addressed.