Controlling Tin Halide Perovskite Crystallization by Blade Coating Toward Reproducible and Efficient Solar Cells

Abstract Tin‐based perovskites have shown significant potential for photovoltaics applications due to their reduced toxicity and ideal bandgap when compared with the Pb counterpart. However, the utilization of industry‐compatible and scalable fabrication techniques has remained limited to date, due to the unique crystallization properties of tin‐based perovskites. Here, tin perovskite solar cells prepared using a two‐step blade coating process is reported. The broad exploration of the space of parameters and the corresponding crystallization control mechanisms showed that waiting time and solvent nature are equally important as coating speed and coating temperature in enhancing the quality of tin(II) iodide films deposited in the first step and the subsequent conversion in the second step. Highly reproducible and efficient tin‐based devices are achieved, exhibiting a maximum power conversion efficiency (PCE) of 10.7% and an impressive fill factor (FF) of 79%. To the knowledge, these values are among the highest reported thus far using a scalable technique. Additionally, it is important to notice that the devices retain over 90% of the initial PCE over 4 months in an inert atmosphere and exhibit good operational stability. The results demonstrate a clear roadmap towards fabricating tin perovskite devices with industry‐compatible techniques.