Interface induced transition from bipolar resistive switching to unipolar resistive switching in Au/Ti/GaOx/NiOx/ITO structures

Abstract

We report the transition from bipolar resistive switching (BRS) to unipolar resistive switching (URS) in the Au/Ti/GaO_x/NiO_x/ITO device at room temperature. After the proper soft breakdown of the p–n junctions (GaO_x/NiO_x), the switching operation could be easily transferred from BRS to URS mode. The BRS and URS behaviors are possibly related to the interfacial variation of the Ti/GaO_x Schottky junction barrier and GaO_x/NiO_x p–n junction barrier, respectively. The high/low resistance state can be distinguished clearly and be switched reversibly under a train of voltage pulses in both BRS and URS modes. The endurance characteristics show good reliability of the stored resistance state. These results suggest a potential device for the next generation of nonvolatile memory applications.