Effect of isothermal annealing on structural, morphological, optical and electrical properties of N-type TiO2 thin films

In this research, influence of post-annealing temperatures on structural, optical and electrical properties of TiO₂ thin films has been outlined. The TiO₂ films were deposited on p-type silicon substrates using the spin coating technique and were thermally treated at different temperatures (300, 400 and 500°C). The crystalline structural properties of deposited films were characterized by X-Ray Diffraction (XRD) observed that the deposited films was found to be amorphous and transform to anatase crystalline phase as film heat- treated above 300°C, while diversification of the surface morphology was examined using Atomic Force Microscopy (AFM) shows the RMS roughness and the thickness of films changed drastically with the particles growth conditions. To get the information about the electrical properties of the thin films, the current-voltage (IV) characteristics were analyzed under dark condition by using two-point probe system. The optical properties of the TiO₂ films were investigated using UV-Vis spectrophotometer found that with increase in the annealing temperature, the absorption edge gets shifted to higher wavelength, a significant decrease in transmittance and the energy band gap (Eg) values leading to decreased.