At present, the highest power conversion efficiency (PCE) of perovskite solar cells (PSCs) has exceeded 25%, which exhibits great potential for commercial applications. Obtaining pinhole-free, superior crystal, and high-quality perovskite films with fewer defects by adjusting the lead iodide (PbI₂) intermediate films in a two-step sequential deposition has become research arousing general interest. Herein, a heterogeneous lead iodide (HLI) structure with two (0 0 1) interplanar distances (9.0 Å and 6.9 Å), can optimize the crystallization process of perovskite to get better surface morphology and is constructed by intercalated choline chloride (a kind of vitamin B4, VB4). HLI simultaneously improves the carrier lifetime of perovskite film from 1.96 µs to 3.28 µs and reduces defect state density. Together with better morphology and lower defect state density, the open circuit voltage (V_OC) and PCE based on (FAPbI₃)_0.97(MAPbBr₃)_0.03 is significantly boosted. In addition, with double-sided modification, HLI produces an excellent PCE of 24.27% with a V_OC of 1.21 V. We believe that the novel heterogeneous PbI₂ structure could be a generic method to improve the efficiency of PSCs.

目前，钙钛矿太阳能电池（PSC）的最高功率转换效率（PCE）已超过25%，具有巨大的商业应用潜力。通过调整两步顺序沉积中的碘化铅（PbI ₂ ）中间膜来获得无针孔、晶体优良、缺陷少的高质量钙钛矿薄膜已成为引起普遍关注的研究。在这里，异质碘化铅（HLI）结构具有两个（0  0 1）晶面间距（9.0 Å和6.9 Å），可以优化钙钛矿的结晶过程以获得更好的表面形貌，由插层氯化胆碱（一种维生素B4，VB4）构成。HLI 同时将钙钛矿薄膜的载流子寿命从 1.96 µs 提高到 3.28 µs，并降低了缺陷态密度。连同更好的形貌和更低的缺陷态密度，显着提高了基于(FAPbI ₃ ) _0.97 (MAPbBr ₃ ) _{0.03的开路电压(} V _OC )和PCE 。此外，通过双面改性，HLI 产生了 24.27% 的出色 PCE，VOC为 1.21 V。我们相信新型异质_PbI2结构可能是提高 PSC 效率的通用方法。