Electrochromic and morphological investigation of dry-lithiated nanostructured tungsten trioxide thin films

Electrochromic properties of porous nanostructured thin films of tungsten trioxide were investigated. Films were fabricated at normal and high vapor incidence angles with the technique of glancing angle deposition in a thermal evaporation chamber. A dry lithiation method was subsequently used to intercalate films with lithium atoms. Coloration in both visible and near-infrared regions was observed with lithium insertion. We report on the morphology, porosity, and optical properties of as-deposited and lithiated films, and discuss the role of substrate tilt in comparing the coloration efficiency of these films.