Enhanced Ferroelectric Performance of P(VDF-TrFE) Composites via MAPbI3-Mediated Crystallization for Flexible Memory Applications

We report a material-engineering strategy in which methylammonium lead iodide (MAPbI3) perovskite is added to poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) composites to overcome intrinsic polarization and stability limitations. MAPbI3 incorporation enhances crystalline ordering and ferroelectric response in P(VDF-TrFE) composites, enhancing β-phase formation and strengthening dipole alignment through electrostatic interactions with -CF2- dipoles while simultaneously increasing dielectric permittivity and suppressing depolarization-field-driven polarization loss. With increasing MAPbI3 content, the composite films exhibit progressively improved ferroelectric performance and reach an optimum at 1.0 wt %, exhibiting a substantial increase in remanent polarization (2Pr from 13.7 to 18.4 μC/cm2), a 2.6-fold enhancement in the ferroelectric field-effect transistor (FeFET) on/off ratio, and a memory window expansion of 0.3 V. However, extremely high loadings and excessive MAPbI3 incorporation lead to aggregation and leakage-related degradation, resulting in reduced crystallinity and switching stability. Using P(VDF-TrFE) composites with optimized MAPbI3 composition, the composite FeFETs achieve extended retention up to 103 s, while the flexible ferroelectric capacitor (FeCAP) maintains stable ferroelectric switching after 10,000 mechanical bending cycles, demonstrating excellent mechanical resilience. These results demonstrate a practical material-engineering strategy for high-performance and mechanically reliable ferroelectric memory using a polymer-perovskite composite design.