Effects of Mo Doping on Thermochromic Properties of Vanadium Dioxide Thin Films

The Mo doped VO(2) thin films were prepared by inorganic sol-gel process and vaccum post-annealing treatment on the fused-quartz substrates. The films were analysed by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The resistance-temperature property and 7.5-14 mu m infrared thermochromic property were tested, and the effects of Mo doping on the thermochromic properties of VO(2) thin films were studied. The results show that the Mo atoms enter the crystal lattice of VO(2) and substitute some V atoms, and the temperature of phase transition decreases gradually with the increase of doping concentration. But the contrast of electrical resistance decreases compared to the undoped VO(2) thin film. When the Mo doping level is 5%(wt.%, MoO(3):V(2)O(5)), the phase transition temperature is 45 degrees C. The infrared thermal images show that the Mo doping VO(2) thin film can control its 7.5-14 mu m infrared radiation intensity actively and lower its radiation temperature at a lower temperature level when the real temperature increases.