Proton-Transfer Ferroelectrics With High Switching Endurance

Reliable organic ferroelectrics for memory applications require high endurance under repeated electrical switching. Here we demonstrate robust fatigue resistance in highly crystalline 2-methylbenzimidazole (MBI) films grown by low-temperature deposition followed by restrained crystallization (LDRC) on interdigital electrodes. Switching kinetics analyzed using the Kolmogorov-Avrami-Ishibashi (KAI) model reveals characteristic millisecond switching times and quasi-one-dimensional domain growth associated with proton transfer along hydrogen-bond chains. Guided by these kinetics, we examined the switching endurance under a stringent protocol that ensures complete polarization reversal. After ~10⁸ continuous cycles (~2 weeks), the remanent polarization shows a small initial wake-up behavior (~10% increase within the first 10⁴ cycles), followed by stabilization at values close to the initial polarization, indicating robust ferroelectric endurance under prolonged electrical cycling. The combination of LDRC-enabled high crystallinity and localized proton-transfer switching, which introduces minimal structural perturbation during polarization reversal, may have enabled this fatigue tolerance and highlight MBI as a simple, fluorine-free platform for durable organic ferroelectric devices.