Designing Ionic Liquids as the Solvent for Efficient and Stable Perovskite Solar Cells

As a green solvent, ionic liquids (ILs) are considered as a promising alternative to conventional polar aprotic solvents for the production of efficient and stable perovskite solar cells (PSCs). Moreover, with the use of IL solvents, perovskite films can be prepared without antisolvent treatments in an ambient environment instead of in a glovebox with inert gases, which simplifies the film manufacturing process and is favorable for industrialization production. However, the type of IL solvents that have been studied is limited, and the influence of IL molecular structures on the perovskite-film crystallization and device performance is not completely understood. In this work, four different ILs, methylammonium formate (MAF), methylammonium acetate (MAAc), methylammonium propionate (MAP), and mthylammonium isobutyrate (MAIB), are synthesized as the perovskite precursor solvents. The interaction between the functional groups of the synthesized solvents and Pb