Electrochromic switching of WO3 nanostructures and thin films

We present transmission measurements through tungsten tri-oxide nanostructures and thin films prepared by sol–gel process on micro-contact printed substrates. Identical electrochromic switching times are found for both the nanostructures and the bulk films with equal thicknesses upon intercalation of H⁺ ions. We attribute the large change in the transmission through nanostructures at 632 nm, which can not be solely explained by absorption, to diffraction effects. PACS 73.40.Cg; 73.40.Mr; 78.20.-e; 78.67.n