Electrochromic properties of nanostructured WO₃ thin films deposited on ITO/PET substrate modified by Pt sputtering

Abstract To enhance the electrochromic(EC) properties of WO 3 thin films, The ITO/PET substrate was modified with Pt sputtering. Subsequently, nanostructured WO 3 thin films were deposited on the modified substrate via DC magnetron sputtering at a glancing angle of 80°. FE-SEM was employed to examine the surface/cross-sectional morphology of the WO 3 thin films. The films’ electrochemical and optical characteristics were tested using an electrochemical workstation and a UV-visible spectrophotometer. The results revealed that the WO 3 thin films have a porous nano-columnar structure. The sputtering of Pt makes the WO 3 thin film dense. The ion diffusion rates were determined to be D in =6.64×10 −12 cm 2 /s and D de =7.06×10 −12 cm 2 /s, respectively. The optical modulation amplitude was found to be 36%, and the coloring efficiency was 10.60 cm 2 C −1 . The coloring and bleaching response time was corresponding to t c =9.4 s and t b =10 s. The sputtering process of Pt needs to be further optimized to find feasible parameters to enhance the EC properties of the WO 3 thin films.