Preparation of titanium dioxide (Tio2) thin films by sol.gel dip coating method

Titanium dioxide (TiO2) thin films have been receiving much attention in the past as their chemical stability, high refractive index, and high dielectric constant [1], allow their use as components in optoelectronic devices, sensors, photo catalysis [2], solar cells [3], and wave guides [4]. Titanium dioxide thin films have been prepared from tetra-butylorthotitanium solution and buthanol as a solvent by sol.gel dip-coating method on an ITO substrate. The samples obtained were characterized by different experimental techniques: X-ray diffraction; Raman spectroscopy; scanning electron microscopy (SEM), optical microscopy, Photoluminescence, infrared and ultraviolet spectroscopy. The X-ray diffraction (XRD) results showed that TiO2 thin film at 300 degree C was amorphous, and transformed into the anatase.brookite at 400 degree C, the crystallite size of TiO2 thin films was increased with increasing temperature gives sizes in the range 5 to 25 nm. The observed by scanning electron microscope (SEM) shows that the coating was transparent and homogeneous without any visual cracking over a wide area, and multiple coating increased thickness, but did not affect the uniformity of the film. The film thickness varies, depending on the number of dipping iterations, between 20 (1 layer) and 153.6 nm (4 layers). The refractive index increases with increasing temperature, and the porosity of TiO2 thin films, however, shows the opposite trend