Complex phenomena are prevalent during the formation of materials, which affect their processing-structure-function relationships. Thin films of methylammonium lead iodide (CH₃NH₃PbI₃, MAPI) are processed by spin coating, antisolvent drop, and annealing of colloidal precursors. The structure and properties of transient and stable phases formed during the process are reported, and the mechanistic insights of the underlying transitions are revealed by combining in situ data from grazing-incidence wide-angle X-ray scattering and photoluminescence spectroscopy. Here, we report the detailed insights on the embryonic stages of organic-inorganic perovskite formation. The physicochemical evolution during the conversion proceeds in four steps: i) An instant nucleation of polydisperse MAPI nanocrystals on antisolvent drop, ii) the instantaneous partial conversion of metastable nanocrystals into orthorhombic solvent-complex by cluster coalescence, iii) the thermal decomposition (dissolution) of the stable solvent-complex into plumboiodide fragments upon evaporation of solvent from the complex and iv) the formation (recrystallization) of cubic MAPI crystals in thin film.

复杂的现象在材料的形成过程中普遍存在，这会影响它们的加工-结构-功能关系。甲基铵碘化铅薄膜 (CH ₃ NH ₃ PbI ₃, MAPI) 通过旋涂、抗溶剂滴和胶体前体退火处理。报告了该过程中形成的瞬态和稳定相的结构和性质，并通过结合来自掠入射广角 X 射线散射和光致发光光谱的原位数据揭示了潜在转变的机制见解。在这里，我们报告了对有机-无机钙钛矿形成的胚胎阶段的详细见解。转化过程中的物理化学演变分四个步骤进行：i) 多分散 MAPI 纳米晶体在抗溶剂液滴上的即时成核，ii) 亚稳态纳米晶体通过簇聚结瞬间部分转化为正交溶剂复合物，