Using Low‐Cost Additive to Improve Perovskite Crystallization for Efficient Solar Cells

Abstract

In the two‐step sequential deposition, the reaction of PbI2 and organic halides for conversion to perovskite is crucial for achieving high‐performance perovskite solar cells, which heavily depends on the morphology of the PbI2 film. The highly structured and dense PbI2 film is not conducive to the diffusion of organic halides in the planar heterojunction. To solve this problem, acetone is introduced into the PbI2 precursor as the regulator of the film morphology. The addition of acetone weakens the interaction between dimethyl sulfoxide and PbI2, leading to the appropriate morphology of PbI2 film. Therefore, PbI2 can react with organic halides and convert to perovskite more efficiently. The high‐quality FA1−xMAxPbI3 perovskite film with reduced defect density is achieved. The device delivers an outstanding power conversion efficiency enhancement with a low‐cost additive.