engleski

Electrical Conductivity of Nanostructured TiO2 Films on Glass Substrate Measured by Impedance Spectroscopy

Films containing nanosized grains of titanium dioxide (TiO2) are widely used in research into mainly optical, photovoltaic, photochromic and electrochromic devices. In most cases there is a desirable average grain size, but also a porosity of TiO2. Films of titanium dioxide derived by organic sol-gel route were investigated by transmission electron microscopy. It shows them as polydispersed and porous, with nanometer sized grains. Measurements by grazing-incidence small-angle X-ray scattering (GISAXS) showed that grain sizes vary with the thickness of the films. In order to determine electrical properties of nano-TiO2 films, samples were characterised by impedance spectroscopy (IS). We have found the dependence of electrical conductivity upon the grain sizes in nanostructured films of TiO2. The experiment was done in the range of film˘s thickness from 200 Å to 1200 Å. Porosity for these films thickness is constant and expressed by internal specific surface equals Ss= 1 nm-1.

titanium dioxide; GISAXS; IS

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