Structural and optical properties of titanium dioxide thin film deposited byspin-coating technique

This research investigates the effects of thermal annealing on the optical, morphological and structural properties of Tio2 thin film. Tio2 was deposited on glass substrate by spin –coating technique using spin –coater model laurel WS-650Hz-23NPP. Surface morphology of thin film was studied using Scanning Electron Microscope (SEM) model ASPEX 3020. The optical absorbance and transmittance measurements were recorded by using a single beam spectrophotometer Avantes model Avalight-DH-5-BAL. After annealing at different temperature for one hour from 1000C to 5500C with Carbolite tubular oven model Srw 21-501042 Type-CT17, the morphology, optical properties of TiO2 thin film were obtained. Observation showed that as the annealing temperature increases there is increase in absorption of photon energy and as the wavelength increases the absorption decreases. It also shows that transmittance increases as the wavelength increases and decreases with increases in annealing temperature. SEM reveal as annealing temperature increases, the grain size of Tio2 gradually increases. The energy gap was observed and determined, the band gap energy decreases from 3.3 eV to 3.05eV as the annealing temperature increases. The impact of heat treatment of TiO2 thin-film on the microstructure, surface roughness, photon absorption, and the band gap energy was obtained.