The preparation of perovskite materials is a critical step in achieving high-efficiency perovskite solar cells. At the molecular scale, PbI₂ and CH₃NH₃I can rapidly react through self-assembly to form CH₃NH₃PbI₃. Thus, whether in solid, liquid, or gas phases, thorough mixing of the two raw materials can yield the desired perovskite material. However, for thin-film solar cell light-absorbing layers with thicknesses below 1 μm, the large perovskite crystals produced by solid-phase reaction methods are clearly unsuitable.
