Multilateral Passivation Strategy in Post-Synthetic Flexible Metal–Organic Frameworks for Enhancing Perovskite Solar Cells
Jian Zhang, Liping Hu, Wei Cao, Yayu Dong, Debin Xia, Kaifeng Lin, Yulin Yang
Abstract
The photovoltaic performance of perovskite solar cells is severely limited by the innate defects of perovskite films. Metal–organic framework (MOF)-based additives with luxuriant skeleton structures and tailored functional groups show a huge potential to solve these problems. Here, a multilateral passivation strategy is performed by introducing two alkyl-sulfonic acid functionalized MOFs, MIL-88B-1,3-SO 3 H and MIL-88B-1,4-SO 3 H, respectively, obtained from MIL-88B-NH 2 through a post-synthetic process, for coordinating the lead defects and inhibiting non-radiative recombination. The flexible MIL-88B-type frameworks endow both functionalized MOFs with excellent electrical conductivity and preferable carrier transport in the hole-transport materials. Compared with the original MIL-88B-NH 2 and MIL-88B-1,4-SO 3 H, MIL-88B-1,3-SO 3 H exhibits optimal steric hindrance and multiple passivation groups (−NH 2, −NH–, and −SO 3 H), achieving the champion doped device with an enhanced power conversion efficiency (PCE) of 22.44% and excellent stability, which maintains 92.8% of the original PCE under ambient conditions (40% humidity and 25 °C) for 1200 h.