Effect of titanium dopant on physical and optical properties Of Wo 3 thin films prepared by sol-gel method

Abstract

In this present work, the influence of incorporated Ti dopants on the physical and optical properties of WO 3 sol-gel derived thin films are investigated and represented. Ti-doped WO 3 thin films with different Ti doping contents (5 wt%, 10 wt%, and 20 wt%) are fabricated on F-doped tin oxide substrates using the spin coating technique. Tungsten powders and titanium butoxide are used as starting sources of the W and Ti ions, respectively. After the coating process, as-deposited films are annealed at 500°C for 2 h in ambient air. The effects of the dopant on the crystal structure, surface morphologies, chemical bonding, and optical properties of the films are investigated by the X-ray diffraction technique (XRD), scanning electron microscopy, Fourier transform infrared (FTIR), and ultraviolet-visible spectrophotometry. The XRD results indicate the monoclinic structure of the prepared films with a significant alteration in the crystalline size when the film was incorporated with the Ti dopant. The FTIR results reveal the deterioration in the W and O bonding as the film is doped with the Ti dopant. The optical band gaps of the films exhibit a significant blue shift with increasing the Ti doping content. The optical density change and cyclic voltammetry results indicate that the performance of WO 3 film applied as a smart window or energy storage can be enhanced by doping with Ti ions.