Influence of Nb doping on the phase transition properties of VO2thin films prepared by ion beam co-sputtering deposition

Abstract

The Nb-doped VO 2 thin films were successfully prepared on the glass substrates by ion beam co-sputtering at room temperature and post annealing under the air condition. The effects of the preparation processing and Nb doping on the thermal hysteresis loop and phase transition temperature of the VO 2 thin films were analyzed by resistancetemperature measurement. The results show that Nb doping significantly changes the surface morphologies of VO 2 thin films, and Nb-doped VO 2 thin films exhibit VO 2 (002) preferred orientation growth with greatly improved crystallinity and orientation. Compared with pure VO 2 , the phase transition temperature of Nb-doped VO 2 thin films drops to 40 oC, and the width of thermal hysteresis loop narrows to 8 oC. It is demonstrated that Nb-doped VO 2 thin films prepared by ion beam co-sputtered at room temperature have an obvious thermal sensitive effect, and keep a good characteristic from metal to semiconductor phase transition.