Coloration and bleaching mechanism of tungsten oxide thin films in different electrolytes

In the present paper, the authors report on the electrochromic properties of electron beam evaporated tungsten oxide (WO3) thin films at different electrolytes. The authors observe the better electrochromic performance for the as deposited room temperature prepared films than the higher substrate temperature prepared films and annealed films. In addition, the less reversible coloration was observed for the heavier ion (K+) intercalation/deintercalation than the lighter one (Li+), which may be due to the effect of microstructure of the films, and ion mobility. The possible role of electrochromic performance in the mechanism of film crystallinity has been discussed.