Scaling Up Perovskite Solar Cell Fabrication: Antisolvent‐Controlled Crystallization of Printed Perovskite Semiconductor

Scaling up perovskite solar cells stands as one of the frontiers in advancing this rapidly growing technology. Yet, controlling perovskite thin‐film crystallization during and post‐printing differs significantly from lab‐scale processes that have yielded record device efficiencies. This study investigates antisolvent treatment for slot‐die‐coated perovskite solar cells using in situ optical spectroscopy and comparing among multiple antisolvents. The antisolvent bath used in slot‐die coating affects the perovskite crystallization and film quality differently when comparing to the established spin‐coating antisolvent treatment process. A novel dynamic antisolvent method, employing either vortex or laminar flow, is developed. It outperforms steady‐bath techniques in generating high‐quality, haze‐free films. Optimization studies identify critical treatment times. Implementing this novel antisolvent treatment leads to a peak average power conversion efficiency of 15.62% and the highest device efficiency of 18.57%, an excellent performance for slot‐die‐coated MAPbI 3 devices printed and tested under ambient conditions. The method is validated for an alternative perovskite composition, FA 0.9 Cs 0.1 PbI 3 , and printing technique, blade coating. This research highlights the importance of in situ analysis for enhancing perovskite film quality and introduces scalable approaches for controlling large‐area film crystallization kinetics, driven by the demand for efficient and scalable manufacturing processes in the field of perovskite solar cells.