Quasi–symmetric Electrochromic Device with two kinds of Amorphous Tungsten Oxide Films

Thin amorphous films of tungsten oxide form the basic for a passive electrichromic device, in which a film is colored blue by simultanous injection of ions and electrons. Tungsten oxide films are usually used as a electrochromic(EC) layer. In this paper, two kinds of amorphous tungsten oxide films are made by thermal evaporation. One shows high color efficiency, and is good for EC layer use. The other shows low color efficiency but high ion injected charge, and is good for counter–electrode(CE), A qusi–symmetry electrochromic device is made by using this two different amorphous tungsten oxide films.