Resistive switching behavior of Pt/Mg0.2Zn0.8O/Pt devices for nonvolatile memory applications

Highly c-axis oriented Mg0.2Zn0.8O thin films with hexagonal structure were prepared on Pt/TiO2/SiO2/Si substrates by sol-gel spin coating technique. The Pt/Mg0.2Zn0.8O/Pt devices showed a reversible and steady resistance switching characteristic. The resistance switching from low resistance state (LRS) to high resistance state (HRS) with a resistance ratio of HRS to LRS of about 25 was achieved at a voltage of as low as 0.65 V. The dominant conduction mechanisms of LRS and HRS were explained by Ohmic behavior and trap-controlled space charge limited current, respectively. Furthermore, formation of conducting filaments in LRS was suggested. This study indicates that the Pt/Mg0.2Zn0.8O/Pt device may be a promising candidate for memristor applications.