Electrochromic performance of PECVD-synthesized WOxCy thin films on flexible PET/ITO substrates for flexible electrochromic devices

Electrochromic performance of WOxCy films deposited onto 60 Ω/□ flexible PET (polyethylene terephthalate)/ITO (indium tin oxide) substrates by low temperature plasma-enhanced chemical vapor deposition (PECVD) was investigated. It was proven that extraordinary electrochromic performance was provided when the precursor [tungsten carbonyl, W(CO)6; TC] vapor, carried by argon gas, was mixed with air gas and synthesized by radio frequency (r.f.) power at room temperature (23 °C). Cyclic voltammetry switching measurements found that only low driving voltages from − 1 V to 1 V were needed to provide reversible Li+ ion intercalation and de-intercalation. The light modulation with up to 63.6% of transmittance variation at a wavelength of 650 nm was obtained for 150 cycles of Li+ intercalation and de-intercalation in a 0.1 M LiClO4-PC (propylene carbonate) electrolyte.