Nanocrystalline TiO2 thin films on soda-lime-silica glass by using a titanium naphthenate precursor

TiO2 thin films were prepared on soda-lime-silica slide glasses by spin coating-pyrolysis process using titanium naphthenate as a starting material. Precursor films were prefired at 500 degreesC for 10 min in air and finally annealed at 500, 550 and 600 degreesC for 30 min in air, followed by rapid cooling. Crystallinity of the TiO2 films was investigated by X-ray diffraction (XRD) analysis. A field emission-scanning electron microscope and an atomic force microscope were adopted for characterizing the surface morphology and the surface roughness of the TiO2 films. After final annealing at 550 and 600 degreesC, the XRD patterns consist of only anatase peak of TiO2 film. Films annealed at 500 and 550 degreesC exhibited flat surfaces. On the contrary, with the increase in annealing temperature to 600 degreesC, the TiO2 film showed growth of three-dimensional needle-shaped grains. For all samples, high transmittance at visible range was obtained by ultra violet-visible-near infrared spectrophotometer. (C) 2003 Elsevier Science B.V. All rights reserved.