Lead‐Free Cesium Metal Halide Perovskite via Solvent‐Free Mechanosynthesis Route

Recent advancements in lead halide perovskites opened up an avenue for vast optoelectronic applications. However, lead toxicity and the complicated synthesis process posed major obstacles to their further practical applications. To address these issues, a facile and robust mechanochemical synthesis of cesium manganese halide (Cs 3 MnX 5 , X = halide element) was developed via a highly efficient solvent‐free ball milling strategy. This green approach exempted the utilization of any harmful organic solvents, thereby enabling the fast and cost‐effective production of lead‐free Cs 3 MnX 5 with excellent optical properties. Cs 3 MnX 5 perovskites with mixed halide compositions could also be readily fabricated through this eco‐friendly approach at room temperature without any post‐purification. Furthermore, the robustness of the ball milling strategy was proved by fabricating zinc‐doped Cs 3 MnX 5 perovskites with enhanced thermal stability and ambient stability. These features demonstrated that ball milling was highly efficacious for producing high‐quality non‐toxic halide perovskites, which could be used in light‐emitting diodes.