Inorganic lead halide perovskite CsPbBr₃ offers attractive photophysical properties and phase stability for high-performance optoelectronic devices. However, CsPbBr₃ films produced by the classic solution-based two-step method are always accompanied with impurity phases of CsPb₂Br₅ and Cs₄PbBr₆, which represents a major efficiency-limiting factor for future advances of CsPbBr₃-based devices. The challenge lies in the complexity of the Cs-Pb-Br phase system, requiring both spatially and temporally precise control of the precursor stoichiometry during solution-phase growth of CsPbBr₃ films. By adopting 2-methoxyethanol as the solution conversion medium instead of commonly applied methanol, the reaction between CsBr and PbBr₂ can be finely controlled to yield single phase CsPbBr₃ films within a few minutes; extending the solution-conversion step to 24 h does not alter the phase purity of resulting CsPbBr₃ films. The present work paves the way to regulate the crystal growth behaviors of two-step solution-processed CsPbBr₃ films by simple solvent engineering.

无机卤化铅钙钛矿 CsPbBr ₃为高性能光电器件提供了有吸引力的光物理特性和相稳定性。然而，通过经典的基于溶液的两步法制备的 CsPbBr ₃薄膜总是伴随着 CsPb ₂ Br ₅和 Cs ₄ PbBr _{6的杂质相，这是 CsPbBr 3}基器件未来发展的主要效率限制因素. 挑战在于 Cs-Pb-Br 相系统的复杂性，需要在 CsPbBr _{3的溶液相生长过程中在空间和时间上精确控制前体化学计量}电影。采用2-甲氧基乙醇代替常用的甲醇作为溶液转化介质，可精细控制CsBr与PbBr ₂的反应，在几分钟内生成单相CsPbBr _3薄膜；将溶液转化步骤延长至 24 小时不会改变所得 CsPbBr ₃薄膜的相纯度。目前的工作为通过简单的溶剂工程调节两步溶液处理的 CsPbBr _{3薄膜的晶体生长行为铺平了道路。}