Study On Improvement Of Electrochromic WO_x Film By Doping

Owing to the special performance of continuous and reverse photoelectric property which can be manually controlled, electrochromic film materials, which are paid attention to by the science and technology world, and studied actively, have been widely applied in many fields, especially in the electrochromic devices. Among many electrochromic materials, WO₃ is regarded as one of the most potential materials because of its high coloration efficiency, strong reversibility, short transmission response time, long cycle life and lower cost. It is a pity that they are far from practical use, and it is important work that the material is put into practice. There are some ways to improve the films'electrochromic performances, for instance, optimizing process parameters and doping method are two effective ways.With pure tungsten and nickel(titanium,vanadium) targets, WO_x and WO_x:Ni(WO_x:Ti,WO_x:V)films were deposited on ITO glass substrates by reactive magnetron sputtering and they were analyzed using spectrophotometer, XRD and XPS. The effect of the process parameters and doping parameters on the electrochromic performances and the structure of WO_x films were discussed.Also the influence mech- anism of doping on WO_x films'electrochromic performances and structure were discussed with the help of the study results by other researchers.The research results show that the WO_x films deposited by the reactive magnetron sputtering were amorphous; in electrochromic reaction their optical properties and structure would change and they behaved good electrochromic performances. The amorphism of Ni(Ti,V)-doping WO_x films, which have better electrochromic properties, tends to be stronger. It is rather complex to the effect of doping on electrochromic of WO_x films, which is related to the doping mode and relative doping quantity. Even doping is helpful to greatly improve the electrochromic properties when the relative doping quantity is in the range of effective doping and around optimized value. The contributions to the improvement of WO_x films of different dopants were different:Ni-doping and V-doping would improve the ability of color storage while Ti-doping would improve the cycle life.