Modification of perovskite films surface/interface through the solvent vapor post-treatment during the film annealing can significantly improve the morphology and crystallinity of the perovskite film, thus enhances the efficiency of the perovskite solar cells (PSCs). In this work, we used a solvent-antisolvent mixture of Dimethyl sulfoxide (DMSO) and chlorobenzene (CB) in the post-treatment of perovskite films during device fabrication to achieve a high-power conversion efficiency of 19.15% in planar perovskite solar cells. The use of chlorobenzene as an additive to DMSO in the post-treatment of the perovskite films was shown to optimize the its morphology and resulted in films with highly fused grains. The modified perovskite film surface not only showed a decreased number of pin-hole and trap density at the surface, but also an increase in the charge transfer at the interfaces and reduced the susceptibility to low-frequency interface polarization. Furthermore, the impedance spectroscopy and I–V characteristics of the electron-only PSC devices also verified the conclusions above. Overall, this work demonstrates mixed solvent-antisolvent post-treatments of perovskite films as an effective modification strategy to tune their surface/interface properties. This approach is anticipated to be extrapolated to other categories of polycrystalline bulk materials and devices.

在薄膜退火过程中通过溶剂蒸汽后处理对钙钛矿薄膜表面/界面进行改性，可以显着改善钙钛矿薄膜的形貌和结晶度，从而提高钙钛矿太阳能电池（PSCs）的效率。在这项工作中，我们在器件制造过程中使用二甲基亚砜 (DMSO) 和氯苯 (CB) 的溶剂-反溶剂混合物对钙钛矿薄膜进行后处理，以在平面钙钛矿太阳能电池中实现 19.15% 的高功率转换效率。在钙钛矿薄膜的后处理中使用氯苯作为 DMSO 的添加剂被证明可以优化其形态并导致薄膜具有高度融合的晶粒。改性钙钛矿薄膜表面不仅显示出减少的针孔数量和表面陷阱密度，但也增加了界面处的电荷转移并降低了对低频界面极化的敏感性。此外，纯电子 PSC 器件的阻抗谱和 I-V 特性也验证了上述结论。总的来说，这项工作证明了钙钛矿薄膜的混合溶剂-反溶剂后处理是一种有效的改性策略，可以调整其表面/界面特性。预计这种方法将外推到其他类别的多晶散装材料和设备。这项工作证明了钙钛矿薄膜的混合溶剂 - 反溶剂后处理作为一种有效的改性策略来调整其表面/界面特性。预计这种方法将外推到其他类别的多晶散装材料和设备。这项工作证明了钙钛矿薄膜的混合溶剂 - 反溶剂后处理作为一种有效的改性策略来调整其表面/界面特性。预计这种方法将外推到其他类别的多晶散装材料和设备。