Upscaling perovskite solar cell fabrication is one of the key challenges in the pathway for commercialization. The slow evaporation of frequently used solvents (DMF or DMSO) limits the fast perovskite layer crystallization, hindering their implementation in large scale deposition methods. Alternatively, methylamine-based precursors have demonstrated rapid crystallization, leading to uniform and specular films. Nonetheless, their application has been limited to MAPbI₃ perovskites with limited efficiency and stability. In this work, we report the requirements for stabilizing α-phase of mixed cation perovskites with high amount of formamidinium by using a methylamine-based precursor. We found that even though, there are many methods for incorporating the methylamine (MA) in precursors or films; the MA content determines stabilization of the α-phase and therefore the viscous-solution route is the only method to incorporate high amounts of MA. At low amounts of MA, perovskite tend to crystallize in 1D dimensional FA₃(MA)PbI₅ phases due to the incomplete solvation of the PbI₆⁻ clusters. In contrast, high MA ratio induces a full solvation of the clusters, leading to a rapid crystallization and a full stabilization of the active 3D α-phase. These results open a window in the development and understanding of new precursors for the fabrication of high efficient, stable and scalable perovskite devices.

钙钛矿太阳能电池制造规模的提升是商业化途径中的关键挑战之一。常用溶剂（DMF或DMSO）的缓慢蒸发限制了钙钛矿层的快速结晶，从而阻碍了其在大规模沉积方法中的应用。或者，基于甲胺的前体已显示出快速结晶，从而导致形成均匀且镜面的薄膜。尽管如此，它们的应用仅限于MAPbI ₃钙钛矿的效率和稳定性有限。在这项工作中，我们报告了通过使用基于甲胺的前体来稳定具有大量甲ami的混合阳离子钙钛矿的α相的要求。我们发现，尽管有很多方法可以将甲胺（MA）掺入前体或薄膜中。MA的含量决定了α相的稳定性，因此粘溶途径是掺入大量MA的唯一方法。在低量的MA的，钙钛矿倾向于在1D结晶维FA ₃（MA）碘化铅_5个阶段由于碘化铅的不完全溶剂化₆ ^-集群。相比之下，高MA比会诱导团簇完全溶解，从而导致活性3Dα相快速结晶并完全稳定。这些结果为开发和理解用于制造高效，稳定和可扩展钙钛矿设备的新型前驱打开了一个窗口。