Cesium lead triiodide (CsPbI₃) presents a desirable band gap, does not require the use of mixed halides for Si tandem solar cells, and possesses relatively high thermal stability owing to its inorganic components. However, the power conversion efficiency (PCE) of CsPbI₃ is lower than that of organic cation-based halide perovskites with identical band gaps. The main factors that govern the PCE of CsPbI₃ are the surface morphology and defect passivation of its thin films on substrates. In this study, we used the sequential dripping of a methylammonium chloride (MACl) solution (SDMS) to obtain highly uniform and pinhole-minimized thin films by controlling the intermediate stages of the crystallization process, followed by surface passivation using octylammonium iodides in ambient air. SDMS accelerated the crystallization process of the CsPbI₃ perovskite layer, resulting in the formation of a uniform and dense surface with few pinholes. Consequently, we fabricated CsPbI₃ solar cells with excellent PCE (20.37%).

三碘化铯铅（CsPbI ₃）具有理想的带隙，不需要为Si串联太阳能电池使用混合卤化物，并且由于其无机成分而具有较高的热稳定性。但是，CsPbI ₃的功率转换效率（PCE）低于带隙相同的有机阳离子基卤化物钙钛矿的功率转换效率。控制CsPbI ₃ PCE的主要因素是其在基材上的薄膜的表面形态和缺陷钝化。在这项研究中，我们通过控制结晶过程的中间阶段，依次滴加甲基氯化铵（MACl）溶液（SDMS）来获得高度均匀且针孔最小的薄膜，然后在环境空气中使用碘化八碘铵表面钝化。SDMS加速了CsPbI ₃钙钛矿层的结晶过程，导致形成了均匀且致密的表面，几乎没有针孔。因此，我们制造了具有出色PCE（20.37％）的CsPbI ₃太阳能电池。