Simultaneous defect passivation and hole mobility enhancement of perovskite solar cells by incorporating anionic metal-organic framework into hole transport materials

Originated from the defects of hybrid halide perovskite and the intrinsic low hole mobility of hole transport materials (HTM), the perovskite degradation and interface carrier recombination hampered the stability and power conversion efficiency (PCE) of PSCs. Herein, we construct a dual-functional layer HTM-FJU-17 by incorporating the (Me2NH2)(+)-encapsulated indium-based anionic metal-organic framework (FJU-17) as a "capsule" into HTM. The FJU-17 capsule would passivate the organic cation vacancies with releasing (Me2NH2)(+) ion, while its anionic framework can stabilize the positively charged oxidized HTM to enhance hole mobility. As a result, PSCs exhibit suppressed charge recombination with PCE improvement from 18.32% to 20.34%, and stable device is obtained with 90% retaining of the original PCE after 1000 h in ambient condition. This work demonstrates the promising potential of using the dual-functional layer based on the large family of anionic MOFs/HTMs to manufacture PSC devices with high performance and simplified preparation processes.