The stabilization of black-phase formamidinium lead iodide (α-FAPbI₃) perovskite under various environmental conditions is considered necessary for solar cells. However, challenges remain regarding the temperature sensitivity of α-FAPbI₃ and the requirements for strict humidity control in its processing. Here we report the synthesis of stable α-FAPbI₃, regardless of humidity and temperature, based on a vertically aligned lead iodide thin film grown from an ionic liquid, methylamine formate. The vertically grown structure has numerous nanometer-scale ion channels that facilitate the permeation of formamidinium iodide into the lead iodide thin films for fast and robust transformation to α-FAPbI₃. A solar cell with a power-conversion efficiency of 24.1% was achieved. The unencapsulated cells retain 80 and 90% of their initial efficiencies for 500 hours at 85°C and continuous light stress, respectively.

黑色相甲脒碘化铅的稳定（α-FAPbI ₃各种环境条件下）钙钛矿的太阳能电池是必要的。然而，挑战仍然存在关于α-FAPbI的温度敏感性₃和用于在其加工严格的湿度控制要求。这里，我们报告稳定α-FAPbI的合成₃，无论湿度和温度的，基于从离子液体，甲胺甲酸生长垂直排列的碘化铅薄膜。所述垂直生长结构具有便于甲脒碘渗透到碘化铅薄膜用于快速和强大变换到众多纳米级离子通道α-FAPbI ₃。获得了具有24.1％的功率转换效率的太阳能电池。未封装的电池在85°C和持续的光应力下，分别保持其初始效率的80％和90％达500小时。