The ionic defects at the surfaces and grain boundaries of organic–inorganic halide perovskite films are detrimental to both the efficiency and stability of perovskite solar cells. Here, we show that quaternary ammonium halides can effectively passivate ionic defects in several different types of hybrid perovskite with their negative- and positive-charged components. The efficient defect passivation reduces the charge trap density and elongates the carrier recombination lifetime, which is supported by density-function-theory calculation. The defect passivation reduces the open-circuit-voltage deficit of the p–i–n-structured device to 0.39 V, and boosts the efficiency to a certified value of 20.59 ± 0.45%. Moreover, the defect healing also significantly enhances the stability of films in ambient conditions. Our findings provide an avenue for defect passivation to further improve both the efficiency and stability of solar cells.

有机-无机卤化物钙钛矿薄膜表面和晶界的离子缺陷对钙钛矿太阳能电池的效率和稳定性均有害。在这里，我们显示了季铵卤化物可以有效钝化几种不同类型的杂化钙钛矿中带负电荷和正电荷的离子缺陷。有效的缺陷钝化降低了电荷陷阱密度并延长了载流子复合寿命，这在密度泛函理论计算中得到了支持。缺陷钝化将p–i–n结构的器件的开路电压赤字降低到0.39 V，并将效率提高到20.59±0.45％的认证值。此外，缺陷愈合还显着增强了环境条件下薄膜的稳定性。