Antisolvent‐Bathing Strategy with Ultra‐Wide Processing Window for Making High‐efficiency Perovskite Solar Cells in Ambient Air

Abstract

Abstract Most record‐efficiency perovskite solar cells rely on spin‐coating with antisolvent dripping, which is fundamentally incompatible with roll‐to‐roll (R2R) manufacturing. The crystallization kinetics of dynamic wet film during spin coating differs widely from the static wet film during R2R fabrication, which makes the existing crystallization control strategies become inapplicable while upscaling. The crystallization regulation of static wet film remains a critical challenge, particularly under ambient conditions. In this study, we employed the antisolvent‐bathing method that can efficiently regulate the crystallization process of static wet films made by drop coating. Through systematic investigation of solvent‐antisolvent interdiffusion kinetics and in‐situ crystallization monitoring via time‐resolved UV–Vis spectroscopy, we identify alkyl chlorides (particularly chloroform) as optimal bathing agents. The champion device made by CF bathing achieved an efficiency of 24.49% under ambient conditions (RH 30%–50%), representing the highest efficiency for perovskite solar cells made by the antisolvent bathing method. The device showed negligible decay after 2256 h storage in N 2 atmosphere. The method demonstrates exceptional environmental resilience to humidity and solvent accumulation, accompanied by an ultra‐wide processing window (10 s–10 min bathing duration, >2 min post‐bathing delay tolerance).