Electrochromic Phenomena in Transition Metal Oxide Thin Films Prepared by Thermal Evaporation

We present an experimental study on the electrochromic properties of MoO3, WO3 and mixed WO3-MoO3 thin films prepared by thermal evaporation. We have constructed symmetric and quasi-symmetric electrochromic cells incorporating the evaporated oxide films as electrochromic layers. Li+ doped V2O5 films served as ion storage layers. The symmetric cells were found to exhibit significantly improved optical properties compared to the quasi-symmetric ones, with very low luminous transmittance values in the colored state, which makes them suitable for large-area window applications.