Carbonyl-Functionalized Polymer for Synergistic Regulation of Perovskite Crystal Quality and Interface Stability

Nonradiative recombination losses induced by surface and grain boundary defects in perovskite films severely limit their power conversion efficiency (PCE) and stability. In this study, effective passivation of film defects was achieved by incorporating poly(methyl vinyl ether-alt-maleic anhydride) (PMVEMA) into the perovskite precursor solution. The carbonyl groups (C═O) in PMVEMA coordinate with Pb2+ ions, thereby enhancing crystallinity, suppressing carrier recombination, and reducing trap-state density. Additionally, the hydrophobic groups in PMVEMA contribute to enhanced environmental stability of the perovskite films, and its flexible polymer chains significantly improve the mechanical flexibility of the devices. Experimental results demonstrate that PMVEMA-modified rigid and flexible devices achieved PCEs of 22.12 and 20.05%, respectively, under ambient air conditions. Moreover, after 600 h of storage in the dark, the devices retained 85% of their initial efficiency, compared to only 44% for the control devices. This study highlights the potential of PMVEMA as a functional additive for enhancing the performance and stability of perovskite solar cells (PSCs), providing an effective strategy for the development of efficient and flexible photovoltaic devices.