Facile Hydrogen‐Bonding Assisted Crystallization Modulation for Large‐area High‐quality CsPbI2Br Films and Efficient Solar Cells

The thermally stable inorganic cesium-based perovskites promise efficient and stable photovoltaics. Unfortunately, the strong ionic bonds lead to uncontrollable rapid crystallization, making it difficult in fabricating large-area black-phase film for photovoltaics. Herein, we developed a facile hydrogen-bonding assisted strategy for modulating the crystallization of CsPbI