n Ag nanoparticle film, which was fabricated by a vacuum deposition method from high purity Ag wire onto cleaned ITO, was uniform and smooth. An Ag/WO3 composite film was prepared by cathodic electrodeposition of WO3 onto the surface of the Ag nanoparticle film. Moreover, an Ag/WO3 nanocomposite film based 5-layer electrochromic device (glass/ITO/Ag-WO3 nanocomposite film/solid electrolyte/poly(3-methythiophene)/ITO/glass) was constructed and its electrochromic properties were also investigated in this paper. In comparison with a single component system (WO3), a substantial enhancement in the electrochromic performance for the Ag embedded WO3 composite system was clearly observed. The method of constructing this electrochromic device was simple and its electrochromic properties appeared good.

Key words: Ag/WO3 nanocomposite film, poly(3-methylthiophene) (PMeT), ionic liquid [BMIM]PF6, electrochromic device (ECD)