Structural investigations on nanocrystalline TiO2 thin films prepared by sol-gel spin coating technique

Nanocrystalline TiO2 thin films have been prepared using titanium isopropoxide precursor by sol-gel spin coating technique. The prepared TiO2 films have been annealed at different temperatures. The structural properties of the films have been studied by using x-ray diffraction method, high resolution transmission electron microscope(HRTEM) and Raman spectra. The as deposited films have been found to be amorphous in nature. The crystalline quality has been observed to improve with annealing temperature. The annealed TiO2 films have been found to exhibit anatase phase. The grain size of the annealed TiO2 films is found to be nearly 25 nm. The photoluminescence spectra of the films annealed at 550 degrees C exhibit a strong band centered around 400 nm.