Characterization of antimony-doped tin oxide films prepared by spray pyrolysis

Abstract

Highly transparent and conductive antimony-doped tin oxide films were prepared by pyrolytic decomposition of a spray solution of SbCl 3, SnCl 4, CH 3CH 2, CH 2OH, H 2O and HCl. The effects of the parametric variations on the film characteristics and the influence on the growth rate were studied. It is shown that our reasonably inexpensive and simple spray pyrolysis system is suitable for obtaining thin films with reasonably satisfactory properties. To improve the overall performance, the system was designed such that the parameters that effect the formation of the films were effectively controlled. The film properties studied include the surface morphology, Hall effect, electrical conductivity, optical transmission in the visible region and band gap. The experimental conditions necessary to obtain films with optimum characteristic features were successfully determined. Films with fairly high optical transmission (> 85% between 450 and 800 nm), low resistivity (∼10 −3 Ω cm) and a direct band gap, E g ≈ 3.82 eV, were obtained at about 430°C substrate temperature, T s, with a relatively high deposition rate and good crystallinity.