Abstract EN:

This work is devoted to the elaboration and characterization of thin nanometric TiO2 films by sol-gel process. Two approaches in preparation of sols have been realized : without additives abd with additives, that modify the titanium dioxyde precursor. The first approach is realized using titanium isopropoxyde (TTIP) as precursor in alcoholic solution with water and acid. The coresponding films(30-210 nm) are deposited by spin-coating and treated at 350-550 °C. They show high transparency in the visible (90%) and refraction index 2 suitable for antireflective application. The second approach is realized using two precursor, TiCl4 and TTIP, in alcoholic solutions with water and acid. Complexing agent 'diethylaminoethyl cellulose, polyethylene glycol, oxalic or citric acids), polymers(diethylaminoethyl cellulose and polyethylene glycol) and surfactants were used as additives. Thin films of different polymorphs were realized : anatase, rarely observed TiO2(B), preferentially oriented brookite. This work shows an influence of synthesis parameters of sol-gel derived TiO2 thin films on crystalline structure, morphology, and useful properties (optical, electrical).