Tantalum oxide thin film ionic conductors for monolithic electrochromic devices

Tantalum oxide (Ta₂O₅) thin films prepared by reactive magnetron sputtering are investigated for their potential use as the ionic conducting layer in all solid state monolithic electrochromic devices. The paper focuses on the influence of Ta₂O₅ coatings on the electrochromic response of amorphous tungsten oxide (a-WO₃), the methods employed for charging during monolithic device fabrication and associated charge losses caused by subsequent deposition of the component layers of monolithic (all solid state) electrochromic devices. The dependence of the electrochromic response and related charge loss processes have been studied for Ta₂O₅ films of different thicknesses prepared on a-WO₃ electrochromic films.