Small Angle X-ray Scattering STUDY OF TiO₂ THIN FILMS AT GRAZING ANGLES

P. Dubcek^1,2, A. Turkovic², B. Etlinger², O. Milat³, M. Lucic-Lavcevic⁴, S. Bernstorff¹ and H. Amenitsch⁵

¹Sincrotrone Trieste, SS 14 km 163,5, 34012 Bassovizza (TS),Italy
²Ruder Boskovic Institute, Bijenicka 54, 10000 Zagreb, Croatia
³Institute for Physics, Bijenicka 46, 10000 Zagreb, Croatia
⁴University of Technology, Teslina 10, 21000 Split, Croatia
⁵Institute for Biophysics and X-ray Structure Research, Austrian Academy of Sciences, Steyrerg. 17, 8010 Graz, Austria

Nanocrystalline titanium dioxide (TiO2) thin films, deposited on the flat glass substrate using various techniques1, have been investigated at the SAXS beamline at Elettra. Because of the strong absorption in the glass substrate, which is commonly used in photo cells, grazing angle scattering was performed.

As the film is built of nanosized particles, the surface roughness disables the total reflection of the primary beam at the whole irradiated surface area. Therefore, the scattering is expected to have two main contributions: the specular scattering from a rough surface and the scattering from the bulk of the film.

In data interpretation it is assumed that the surface roughness corresponds to the bulk structure of the film, which is porous. Therefore, both contributions should indicate the same average particle sizes and film porosity.

The obtained values for the average particle sizes and the specific surfaces are compared for different sample preparations and are correlated to photo cell efficiency.

1.A. Turkovic , M. Ivanda, S. Popovic , A. Tonejc, M. Gotic , P. Dubcek and S. Music, J. Mol. Struc. 410-411(1997) 271