All-inorganic halide perovskite solar cells (PSCs) have acquired great progress, especially CsPbI₂Br. However, their photoelectric conversion efficiency (PCE) remains far below the theoretical predictions. Non-radiative recombination is one of the important issues affecting the photoelectric performance of the PSCs, and the defective lead ions derived from the evaporation of halide ions in the inorganic perovskite are the principal non-radiative recombination centers. Herein, the non-radiative recombination is effectively suppressed by introducing the N-methyl-2-pyrrolidone (NMP) as a Lewis base molecule to passivate the defective lead ions. Therefore, by adjusting the dosage of NMP, the smooth and pinhole-free CsPbI₂Br perovskite film is obtained and the optimized device exhibits a champion PCE of 16.77% with an excellent fill factor (FF) of 0.80. This work proves the effectiveness of passivation using Lewis base molecules to prevent non-radiative recombination defects in inorganic perovskite.

全无机卤化物钙钛矿太阳能电池（PSC）取得了长足的进步，尤其是CsPbI ₂ Br。但是，它们的光电转换效率（PCE）仍远低于理论预测值。非辐射复合是影响PSC光电性能的重要问题之一，而无机钙钛矿中卤离子蒸发产生的有缺陷的铅离子是主要的非辐射复合中心。在此，通过引入N-甲基-2-吡咯烷酮（NMP）作为路易斯碱分子来钝化有缺陷的铅离子，有效地抑制了非辐射重组。因此，通过调整NMP的剂量，可以实现光滑无针孔的CsPbI ₂获得了钙钛矿薄膜，经过优化的器件显示出16.77％的最佳PCE，且填充系数（FF）为0.80。这项工作证明了使用路易斯碱分子钝化来防止无机钙钛矿中非辐射重组缺陷的有效性。