Preparation of nanostructured titania thin films by sol–gel technology

Abstract

This study is concerned with the preparation of hydrolytically active heteroligand complex [Ti(OC₄H₉)_3.61(O₂C₅H₇)_0.39] from titanium butoxide and acetylacetone and with the gel formation kinetics in a solution of this complex upon hydrolysis and polycondensation. Single-layer and double-layer thin films of a solution of this precursor were coated on polished silicon substrates using the dip-coating method. The crystallization of nanostructured titania films during the heat treatment of these xerogel coatings was studied using various protocols; the anatase–rutile phase transition temperature was found to depend on the film thickness. The effects of the precursor solution viscosity on the film thickness and crystallite size were determined.