Electron scattering and effects of sources of light on photoconductivity of SnO2 coatings prepared by sol-gel

Electrooptical properties of sol-gel derived 2 mol% Sb or Nb doped SnO2 films have been measured. The electron density has been calculated considering all the relevant scattering mechanisms and experimental conductivity data measured in the range -197 to 25 C. Results support the hypothesis that both ionized impurity scattering and grain boundary scattering have comparable effects in the resistivity of coatings, for free electron density. Authors measured variation of photoconductivity excitation with wavelength using Xe and D lamp as light sources. Results show that the main band in the photoconductivity spectrum is dependent on the spectral light source emission, the excitation peak reaching 5 eV. This band is due to the recombination process involving O species and photogenerated electron-hole pairs. 14 refs.