A cost-effective process to prepare VO2 (M) powder and films with superior thermochromic properties

VO2 powder with superior phase transition performance was prepared by convenient thermolysis method. The results illustrated that VO2 powder show high purity and crystallinity. VO2 particles are transformed from cluster to quasi-sphere with the increase of annealing temperature. The DSC analysis proves that VO2 show superior phase transition performance around 68 °C. The phase transition temperature can be reduced to 33.5 °C by 1.8 at% tungsten doping. The maximum decreasing efficiency of phase transition temperature is about −30 K/at% with w = 0.4 at%. After mixing VO2 powder with acrylic resin, the maximal visible transmission of the composite thin films on glass is 48% and the transmission modulation at 2000 nm is 37.3% with phase transition temperature of 66.2 °C. Though the phase transition performance is weakened by tungsten doping, the film prepared by 1.3 at% tungsten doped VO2 still show superior transmission modulation about 26.4% at 2000 nm, which means that it is a potential candidate as smart windows.