Reactive sputtering deposition of V2O5 − z on flexible PET/ITO substrates for electrochromic devices

The reactive sputtering deposition of electrochromic thin films of V2O5 − z onto flexible PET/ITO substrates using argon and oxygen at room temperature (23 °C) was investigated. Cyclic voltammetry measurements showed that only low driving voltages, between − 0.6 V and + 1 V, were needed to provide reversible Li+ ion insertion and extraction. XPS showed that thin film with oxygen deficiency z of 0.13 can offer promising light modulation at a wavelength of 400 nm under visible-UV spectroscopy, with up to 36.5% transmittance variation even after 200 cycles of cyclic voltammetry tests.