Investigation of length-dependent characteristics of the voltage-induced metal insulator transition in VO2 film devices

The characteristics of the voltage-induced metal insulator transition (MIT) of VO2 film devices are investigated as a function of ambient temperature and length. At the onset of voltage-induced MIT, an abrupt formation of a conduction channel is observed within the insulating phase. The carrier density of the device varies with ambient temperature (TA) and device length (L) across MIT. As the device length is reduced, a statistically random appearance of the conduction channel is observed. Our results suggest that the primary operation principles of the VO2 device can be chosen between Joule heating effect and the electric field effect.