Vanadium dioxide (VO2) thin films are becoming increasingly important for their efficient thermochromic properties. A semiconductor to metal transition occurs in these films at the temperature (Tt) of 68ºC at which they switch from a transparent state to a highly reflective state in the infrared region. These optical changes are also accompanied by electrical and structural changes in the film. An aspect of great interest and importance in this research world over is the diminution of Tt to near room temperature. Invariably such diminution, achieved through the doping of tungsten atoms (W), entails a diminution in the optical efficiency of the switch.
In the present work a systematic study of the effect of the treatment of sputter deposited VO2 thin films by a fast atom beam (FAB) of argon has been undertaken. VO2 thin films of different thicknesses have been subjected to this treatment and their thermochromic properties (optical and electrical switch, Tt and hysteresis) are evaluated as a function of the FAB treatment duration. The results indicate the rich potential of this approach to VO2 nanostructure control as well as to reduce the Tt without a significant compromise to the optical switch.