Vanadium Dioxide Nanowire Functional Devices

Vanadium dioxide (VO2) is an interesting material due to its first order metal to insulator phase transition (MIT) at a temperature of 340 K. VO2 behaves as an insulator at room temperature while becomes metallic after transition at elevated temperatures. The crystal structure of the material also changes along with the electrical properties. VO2 nanowire which is one-dimensional nanostructure of the material shows more significant physical properties change across the phase transition due to the higher crystallinity compared to thin film. Thus, VO2 nanowire is a preferred candidate for fundamental studies for the metal-insulator phase transition mechanism as well as its potential applications for nanoscale electronics devices. Here, we have studied two functional devices based on the temperature triggered phase transition properties of the as-grown VO2 nanowires. In the first functional device, we have investigated the junction behavior of a VO2 nanowire based crossbar device at various temperatures where the crossbar contains two intersecting VO2 single nanowires. In our second device, we have studied the gating effect of VO2 single nanowire via heat excitation (instead of electric field) and proposed a thermal transistor device based on the temperature dependent phase transition properties of VO2 single nanowire.