Electrodeposition-Based Fabrication and Characteristics of Tungsten Trioxide Thin Film

In this study, tungsten trioxide (WO₃) thin films were electrodeposited on indium tin oxide (ITO) glass to form WO₃-coated glass. The electrodeposition (ED) time (t E D) and ED current (I E D) were varied to control the film thickness and morphology. Furthermore, the crystallization of the thin films was controlled by annealing them at 250°C, 500°C, and 700°C. The results showed that the thickness of the WO₃ thin films increased with t E D and I E D. The as-deposited thin films and those annealed at 250°C were amorphous, whereas the WO₃ thin films annealed at 500 and 700°C were in the anorthic phase. Moreover, the amorphous WO₃-coated glass exhibited high transmittance in visible light and low transmittance in near-infrared light, whereas the anorthic WO₃-coated glass had high transmittance in near-infrared light. An empirical formula for determining the thickness of WO₃ thin films was derived through multiple regressions of the ED process parameters.