Metal halide perovskites have gained a lot of attention par-ticularly in recent years due to their excellent optoelectronic properties and simple scalable processability[1-3].One major application of halide perovskites is solar cells,however,des-pite the power conversion efficiencies(PCEs)have already reached around 25%[4,5],the long-term stability issue of such devices still impedes their commercialization.Ionic liquids,which contain a large asymmetric organic cation and an organ-ic or inorganic anion,have recently been applied to per-ovskite solar cells(PSCs),not only increasing the efficiency but also remarkably improving the long-term stability[6,7].