Abstract
In this study, the nickel oxide (NiO_x) thin films were reactively sputtered at different working pressures in the oxide mode zone for application in flexible all-thin-film electrochromic devices (ATF-ECDs). The working pressure plays an important role on the various properties of the reactively sputtered NiO_x thin film including the deposition rate, grain structure (microstructure), morphology, chemical composition, optical properties and electrochemical properties. The flexible ATF-ECDs with ≥2 Pa NiO_x thin films perform high optical modulation and relatively fast response time during the electrochromic processes. The detailed electrochromic mechanism is discussed.