Role of Thermal Heating on the Voltage Induced Insulator-Metal Transition in VO2

We show that the main mechanism for the dc voltage or dc current induced insulator-metal transition in vanadium dioxide VO2 is due to local Joule heating and not a purely electronic effect. This "tour de force" experiment was accomplished by using the fluorescence spectra of rare-earth doped micron sized particles as local temperature sensors. As the insulator-metal transition is induced by a dc voltage or dc current, the local temperature reaches the transition temperature indicating that Joule heating plays a predominant role. This has critical implications for the understanding of the dc voltage or dc current induced insulator-metal transition and has a direct impact on applications which use dc voltage or dc current to externally drive the transition. DOI: 10.1103/PhysRevLett.110.056601