Improvement in solar cell efficiency based on the MAPbI3 films extracted by a mixed anti-solvent

In this report, we discuss the 22% efficiency improvement of solar cells based on the MAPbI3 perovskite film extracted with a mixed anti-solvent. The film quality of MAPbI3 extracted from the mixed anti-solvent of ether and isopropanol is improved greatly. The average grain size of the film may be enlarged twice. We argue that some solvents residing in the precursor may effectively promote the crystallization process of MAPbI3 to form large grains. We believe that this study may open a method to fabricate high-quality MAPbI3 perovskite films for highly efficient solar cells.