Electrochromic properties of sputtered Ti-doped WO3 films

Ti-doped WO3 films were prepared by the mid-frequency dual-target magnetron sputtering method. The structure and electrochromic properties of the Ti-doped WO3 films were analysed by X-Ray diffraction (XRD), Raman spectroscopy, spectrophotometer, cyclic chronoamperometry and atomic force microscopy (AFM). The results indicate that the crystallinity decrease after the doping of titanium, the channels for ion injection and extraction increase, the responding speed with 5.1% titanium doped becomes faster, and its circle life increases more than four times compared with the undoped WO3 film. In the coloured state, the W-O-W bonds decrease, but the W = O bonds increase. Since the W-O-W bonds break down for Li+ ions' injection and more W = O bonds form, it is more convenient to inject Li+ ions into the Ti-doped film than undoped film because more W-O-W bonds break down in the coloured state.