Step electrical switching in VO2 on hexagonal boron nitride using confined individual metallic domains

Abstract

Vanadium dioxide (VO2) exhibits an insulator–metal transition (IMT) accompanied with a giant resistance change, which is attractive for the application of devices, such as switching devices. Since the behavior of individual domains determines the total IMT property of the VO2 sample, the steep resistance change from a single domain can be identified and utilized in a sample whose size is as small as the individual domain size. Uniquely, micro-structured VO2 thin films on hexagonal boron nitride (hBN) exhibit step resistance changes owing to the confined metallic domains. In this study, we demonstrated step electrical switching in the two-terminal VO2 sample produced on hBN. Operando structural and electric investigation revealed that the emergence of metallic domains in the micrometer space contributes to the step electric current increase. Our results indicate the use of individual metallic domains in VO2 thin films on hBN in the application of novel devices.