Fluorinated Graphene–Lewis-Base Polymer Composites as a Multifunctional Passivation Layer for High-Performance Perovskite Solar Cells

) of 1.247 V and an average power conversion efficiency of 22.91%, higher than those of PMMA-based devices (20.75%, 1.210 V), as well as increasing the device's moisture stability, with over 90% of the initial efficiency maintained after 1200 h of aging at room temperature and a relative humidity of 35%.