A Vapor‐Assisted Repair Strategy for Printing Durable and Reproducible Perovskite Photovoltaics

ABSTRACT The uncontrolled nucleation and crystallization processes of hybrid perovskite materials continue to impede the efficiency tolerance and fabrication reproducibility of large‐area perovskite solar cells (PSCs). Herein, we report a printing‐compatible vapor‐assisted post‐treatment method that promotes the thermodynamically favored formation of the α‐phase perovskite while repairing multi‐dimensional defects throughout the films. Polarity‐optimized solvents have been established as an effective pre‐treatment strategy for both surfaces and grain boundaries, facilitating vapor‐assisted pathways that effectively suppress defect states across the entire thickness. Consequently, the treated PSCs achieved champion power conversion efficiencies (PCEs) of 26.31% (0.04 cm 2 ) and 25.44% (1.01 cm 2 ), while a mini‐module (41.3 cm 2 ) delivered 22.30% with optimal reproducibility, accompanied by enhanced humidity resistance, thermal robustness, and operational stability. Notably, the mini‐module retained nearly 90% of its initial efficiency after 550 h of continuous 1‐sun operation. This method offers a collaborative approach for mitigating the defect enrichment issue during the printing process, which aligns with the requirements of industrial batch production of perovskite photovoltaics.