Application of Ionic Liquids in Perovskite Solar Cells

Perovskite solar cells (PSCs) have been developed at a rapid rate. In just over a decade, the photoelectric conversion efficiency (PCE) of PSCs is comparable with that of crystalline silicon solar cells that are developed over 60 years. The two major research topics of PSCs are the improvements of both PCE and stability. Ionic liquids (ILs) have the characteristics of low saturated vapor pressure, high ionic conductivity and low toxicity, which could find applications in the preparation of high-performance PSCs. The application and mechanism of ILs in PSCs as additive or solvent of perovskite materials and as charge transfer layer or modification layer will be reviewed, while the development trend of ILs in PSCs is prospected.