Preparation of WO3 films by magnetron sputtering: Preparation process and influence of ZnO doping on the electrochromic properties of the films

In this study, zinc oxide (ZnO)-doped tungsten trioxide (WO3) thin films were fabricated using magnetron sputtering. Films'structural changes were analyzed through scanning electron microscopy (SEM), energydispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). With increasing doping power, the crystallinity, grain size, and surface roughness of the WO3 films were enhanced, while the film thickness decreased. These results indicate that ZnO doping significantly affects the surface morphology and structural properties of WO3 thin films. In terms of performance, the film doped at 20w demonstrated optimal electrochromic properties, achieving light modulation of 87.9 % and a coloration efficiency of 24.4 cm2/C within the visible spectrum (400-700 nm), which marks a substantial improvement compared to the undoped film.