Deposition and Characterization of As-Grown and Annealed Titanium Dioxide (TiO₂) Thin Film

In this work, titanium dioxide (TiO₂) was deposited on a microscopic glass substrate by means of the spray pyrolysis method. The precursor was made of one molar solution of titanium(III) chloride propanol and glacial acetic acid thoroughly mixed. The deposited thin films were annealed at 450 and 600°C, respectively. The optical and structural properties of the as-grown and the annealed thin films were studied using a spectrophotometer, X-ray power diffractometer, and scanning electron microscopy. The result obtained revealed that TiO₂ absorbs, reflects, and transmits light in the wavelength range of 200–1000 nm. The TiO₂ thin films have good optical properties in the ultraviolet region of the electromagnetic spectrum. The as-grown and annealed TiO₂ thin films have bandgap energy varying from 1.6–2.2 eV depending on the annealing temperature. The X-ray diffraction study reveals that the peak positions do not change due to the annealing. Still, the annealed sample has a high intensity that seems to depend on the annealing temperature. Annealing of TiO₂ causes the surface to be more uniform, devoid-free, and with improved surface structure.