A method mediated by [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) is developed to synthesize a uniform, purer-phase 2D perovskite capping layer on 3D perovskite films. The PCBM interlayer mediates the reaction of the 2D passivator with the 3D perovskite and prevents grain-boundary etching, enhancing solar cell efficiency and stability.
- Zhimin Li
- Pengfei Guo
- Yuanyuan Zhou