Electrochromic property of tungsten trioxide films prepared by DC magnetron sputtering with oblique angle deposition and thermal oxidation

Abstract

In this work, WO3 thin films were prepared in two steps: First, tungsten (W) films with thickness of 100-300 nm were deposited by DC magnetron sputtering with oblique angle deposition (OAD) technique at 0 and 85. Second, sputtered W films were annealed under air atmosphere at a temperature of 500℃ and different oxidation times for 1-3 h. The structure of WO3 thin films were examined by X-ray diffraction and field emission scanning electron microscope. In addition, the optical and electrochromic properties of the WO3 thin films were measured by a spectrophotometer before and after testing in potassium hydroxide electrolytes. The results showed that the OAD technique can enhance porosity and exert high oxidation in W films. The increase in film thickness and oxidation time indicated that the crystallinity of WO3 films increased. The condition of WO3 films for OAD at 85, thickness of 300 nm, and oxidation time of 1 h showed the best electrochromic property with the highest optical modulation and current density.