ALL-SOLID-STATE ELECTROCHROMIC DEVICE .2. CHARACTERIZATION OF TRANSITION-METAL OXIDE THIN-FILMS FOR COUNTER ELECTRODE

The performance of transition-metal oxide thin films used as the counter electrode of all-solid-state ECDs has been studied by measuring the optical density change, the current- and potential-wave forms under constant voltage conditions. The transition-metal oxides such as MoO3 showed better performance than oxides such as Cr2O3. The former oxides, which contain absorbed and hydroxylated water, seem to rather easily donate protons into the proton conductive solid electrolyte in the coloration process and vice versa in bleaching process, while the latter oxides containing adsorbed water appear to need dissociation and/or oxidation of water to produce mobile protons.