A Generalized Crystallization Protocol for Scalable Deposition of High‐Quality Perovskite Thin Films for Photovoltaic Applications

Metal halide perovskite solar cells (PSCs) have raised considerable scientific interest due to their high cost‐efficiency potential for photovoltaic solar energy conversion. As PSCs already are meeting the efficiency requirements for renewable power generation, more attention is given to further technological barriers as environmental stability and reliability. However, the most major obstacle limiting commercialization of PSCs is the lack of a reliable and scalable process for thin film production. Here, a generic crystallization strategy that allows the controlled growth of highly qualitative perovskite films via a one‐step blade coating is reported. Through rational ink formulation in combination with a facile vacuum‐assisted precrystallization strategy, it is possible to produce dense and uniform perovskite films with high crystallinity on large areas. The universal application of the method is demonstrated at the hand of three typical perovskite compositions with different band gaps. P‐i‐n perovskite solar cells show fill factors up to 80%, underpinning the statement of the importance of controlling crystallization dynamics. The methodology provides important progress toward the realization of cost‐effective large‐area perovskite solar cells for practical applications.