Device Geometry Insights for Efficient Electrically Driven Insulator-to-Metal Transition in Vanadium Dioxide Thin-Films

Vanadium dioxide (VO2) is a versatile phase change material that undergoes insulator-to-metal transition (IMT) triggered by multiple stimuli such as temperature, light, and electricity. Electrical stimuli offer greater degree of control over selected regions, with high density and addressability. However, there is limited understanding of parameters that govern electrically activated IMT, especially device structure and channel width. This work presents a metal–insulator–metal (MIM) structure to investigate three electrode arrangements: offset, no offset, and overlapping. It is experimentally determined that among the three electrode arrangements, the overlapping configuration of the device needs the least amount of voltage for switching, which is also supported by simulation results. In contrast, IMT in VO2 is independent of extent of overlap between top and bottom electrodes and channel width. These findings are integral to designing and controlling the functional domains of VO2 for energy-efficient, addressable, and scalable micro/nanoscale devices and sensor applications.