All-inorganic perovskite solar cells (PSCs) have attracted wide attention for their excellent thermal stability. However, the detailed crystallization process and complicated phase-transition mechanism of the CsPbX₃ film with different halide compositions (I, Br, Cl) remain mysterious. In this study, systematic investigations are performed via state-of-art in situ grazing-incidence wide-angle X-ray scattering to understand the role of the halide elements in all-inorganic perovskite crystallization kinetics, phase-transition, and stabilization mechanism as well as how film morphology and grain size are affected. Based on these results, we were able to fabricate high-performance ternary halide (I, Br, Cl) all-inorganic PSCs through a precise compositional engineering. Our results provide guidance for an in-depth understanding of all-inorganic perovskite materials and pave the way to obtain high-performance all-inorganic PSCs.

全无机钙钛矿太阳能电池（PSC）的出色热稳定性已引起广泛关注。然而，具有不同卤化物组成（I，Br，Cl）的CsPbX ₃薄膜的详细结晶过程和复杂的相变机理仍然是个谜。在这项研究中，系统研究是通过最先进的原位进行的掠入射广角X射线散射，了解卤化物元素在全无机钙钛矿结晶动力学，相变和稳定机制中的作用，以及膜形态和晶粒尺寸如何受到影响。基于这些结果，我们能够通过精确的组成工程来制备高性能三元卤化物（I，Br，Cl）全无机PSC。我们的结果为深入了解全无机钙钛矿材料提供了指导，并为获得高性能全无机PSC铺平了道路。