Ionic Liquids for Efficient and Stable Perovskite Solar Cells

Abstract Organic‐inorganic hybrid metal halide perovskite materials, as an emerging semiconductor, have been successfully used in the field of solar cells and currently achieved a record efficiency of 25.7% within a decade, surpassing the mature thin film photovoltaic technologies on the market. To further improve the stability and efficiency of the forthcoming commercialization of perovskite solar cells (PSCs), ionic liquids (IL) have been selectively applied to the field of PSCs due to its excellent properties including designability, thermal stability, and conductivity. In this review, by summarizing recent research progress, the mechanism is discussed as IL serve as precursor solvents, additives, interfacial modification layers, independent electron transport layers, and p‐type dopants. Finally, the future research trend of IL has been prospected.