Bi-stable resistive switching in an array of $\hbox {Cu/Cu}_x\hbox {O/Au}$ nanowires

Abstract

A resistive switching system comprising of metal–insulator–metal $(\hbox {Cu/Cu}_x\hbox {O/Au})$ sandwich-structured nanowires embedded within polycarbonate membrane has been investigated. The system switches from non-Ohmic high resistive state (HRS) to Ohmic low resistive state on application of a critical bias of $\sim$2.5 V. The bipolar switching can be performed by applying current bias as well. Driving two suitable currents, $I_{\mathrm{set}}= 50\,\upmu \hbox {A}$ and $I_{\mathrm{reset}}= -0.5\,\hbox {mA},$ we observe highly reproducible switching between two stable resistive states. The switching is initiated by establishment of filamentary conduction path commonly formed in oxide materials. However, the main charge transport in the HRS is governed with modified activated behavior, which is obvious from the antisymmetric, reversible I–V characteristic following $I=aV\exp [(-E_A+b|V|)/k_BT]$ where a, b and $E_A$ are constants. The exponential term corresponds to charge generation by field-enhanced thermal activation process, whereas the linear term is related to mobility.