Self-rectifying resistive switching behavior and analog characteristics in the Bi0.95Er0.05FeO3/ZnFe2O4 heterostructures

Abstract

The development of Resistive Random Access Memory (RRAM) devices is expected to drive a revolutionary change in artificial intelligence, especially playing a key role in neuromorphic computing applications. Novel RRAM devices with self-rectifying and analog characteristics have become a research hotspot in current research areas due to their unique electrical characteristics. Here, a remarkable bipolar resistive switching (RS) behavior with the self-rectifying effects and analog characteristics is observed in the (16-x)Bi_0.95Er_0.05FeO₃/(x)ZnFe₂O₄ (BEFO/ZFO; x = 1, 3, 5, 7) heterostructures, which are prepared on FTO substrates using the sol-gel method. The optimal RS behavior is obtained for the x = 3 sample, including endurance over 1000 operations and stable retention up to 5000 s. The conductive mechanisms of the x = 3 devices at high resistance state (HRS) complies with the Space Charge Limited Current (SCLC) model. In contrast, the low resistance state (LRS) is dominated by the Schottky model. The RS behavior is correlated with the changes in the depletion layer width and barrier height at the p-n junction interface. Moreover, the conductivity of the x = 3 sample increases with successive sweeps of the applied voltage, showing favorable analog characteristics, suggesting the (16-x)BEFO/(x)ZFO heterostructures with the self-rectifying effect offer promising prospects for the RRAM devices in realizing neuromorphic applications.