Improved VO2 thin films for infrared switching

Vanadium dioxide (VO2) undergoes a thermally induced phase transition from a semiconductor to a metal near 68 degree C. The deposition of VO2 thin films by using a process of activated-reactive evaporation provides high-quality VO2-film materials; specifically, the semiconducting phase-extinction coefficient in the infrared is reduced by an order of magnitude without detrimental effect on the corresponding metal phase coefficient. The materials improvement significantly enhances accessible performance limits for optical switching devices, as compared with VO2 thin films deposited by both standard reactive and ion-assisted reactive evaporation