Fabrication and Characterization of Tio2-Organic Thin Film from An Aqueous Solution

Abstract

TiO2-organic thin films were fabricated on SAMs-coated silicon substrate based on layer-by-layer self-assembly process and chemical bath deposition method by a hydrolysis of TiCl4 in acid aqueous solution. The influences of deposition time and solution pH value on structural properties and the thickness of TiO2 films were investigated. The results of UV-vis spectrum show the absorbance of aqueous solutions at 410 nm decreases gradually with increasing deposition time and solution pH value. The thickness of TiO2-organic thin film elevates as increasing deposition time and pH value. The deposition time has significant influence on the surface morphology of films, and when the time is 2 h, a continuous, density and homogeneous film is gained from SEM micrographs. The deposited films consisting of TiO2 nanoparticles are believed to be fully amorphous layers from the results of XRD. The major chemical compositions of thin films are titanium and oxygen as presented in EDS results, and O/Ti atomic ratio is close to the corresponding ratio of 2:1 for stoichiometric TiO2. The transmission infrared spectrum and UV/Vis spectrum of TiO2 film indicate excellent structure and optical properties of films.