Bond and electrochromic properties of WO3 films deposited with horizontal DC, pulsed DC, and RF sputtering

► There are three deposition methods to do the electrochromic layer (WO3 thin film) for the electrochromic device. ► WO3 thin films were deposited on ITO glass and silicon substrate with different gas ratios of oxygen and argon was investigated. ► The Raman spectra exhibited the bond of tungsten with three different deposited methods. ► Optical density and coloration efficiency were discussed for the electrochromic device performance. ► The bleached/colored ability of the cyclic voltammograms (CVs) was pulsed DC > DC > RF.