Complementary Resistive Switching in ZnO/Al2O3 bi-layer devices

This paper reports the complementary resistive switching (CRS) characteristics exhibited by Au/ZnO/Al₂O₃/Fluorine doped tin oxide ( FTO) bilayer device for the first time, where both ZnO and Al₂O₃ are active switching layers exhibiting resistive switching properties. The I-V characteristics of the device initially show bipolar resistive switching (BRS) for a few cycles (~12) before permanently switching to CRS with the extension of SET voltage. The stable CRS state of the device exhibits a high current of ~500 μA during the ON - state and low current of 3x10^-7 A during OFF - state at low input voltage s (-0.5 V to 0.5V) enables the proposed device suitable to use in crossbar array to mitigate the sneak path current. The device performance to write and read processes is evaluated with pulses of magnitudes ~|2.5| V and 1.3 V, respectively, and showed a ~ 60μA difference in read-out current between data bits 0 and 1. Similarly, the device's power consumption is also measured to elucidate that the device is suitable to use as a memory unit with power consumption in the order of microwatts (μW). Further, the possible switching mechanism is demonstrated based on oxygen vacancies migration.