Recrystallization Strategy for Efficient Preparation of Metal Halide Single Crystals with High‐Quality

Abstract Large size high‐quality perovskite single‐crystals are highly desirable for investigating their fundamental materials properties and realizing state of the art electronic/optoelectronic device performance. Herein, a novel single‐crystal growth method is reported by recrystallization of perovskites in oversaturated solutions. Perovskite single crystals including both organic–inorganic hybrid metal halides and their all‐inorganic counterparts can be obtained in large amounts by this method. All of the synthesized perovskite single crystals exhibit large crystal sizes (centimeter level) and exceptional light emission properties. Meanwhile, the single‐crystal growth can be well controlled and the solvent can be reused for cycles of single‐crystal growth, which sheds light on the preparation of perovskite materials in a way of green chemistry. In addition, thermodynamic growth principles for the single‐crystal growth are proposed, providing a universal approval for metal halide single‐crystal synthesis.