Resistive switching in reactive electrode-based memristor: engineering bulk defects and interface inhomogeneity through bias characteristics

Abstract

A novel work on several aspects of current conduction mechanism for resistive switching (RS) of a reactive electrode-based memristor (Al/ZnO/Al) against generally used inert electrode–based devices has been illustrated. Compliance current (Icc), i.e. maximum current through device and stop voltage (Vstop), i.e. maximum Vstop upon device, has been used as bias characteristics to evaluate the effect upon conduction behavior. Effect of change in Icc for constant Vstop and vice-versa upon high resistance state (HRS) and low resistance state (LRS) has been evaluated in terms of change in bulk defects, i.e. oxygen vacancy and interface inhomogenity, i.e. AlOx formation/dissolution. The device shows unipolar resistive switching (URS) at lower Icc (< = 0.1 mA) and transits irreversibly into bipolar resistive switching (BRS) at higher Icc (> = 1 mA). The dominant conduction behavior of the device is found to be homogenous resistive switching (HoRS). The conduction in HRS and LRS is found to be space-charge limited current conduction. Conductive atomic force microscopy results of the thin film switching layer support the HoRS mechanism and also illustrate the role of interfacial oxide in attributing BRS behavior in the Al/ZnO/Al resistive switch. Studies can be utilized in future to further understand the RS conduction mechanism in reactive electrode–based RS and can be applied for multi-state memory applications.