Abstract In this paper, we report structural, electrical, optical, and especially thermoelectrical characterization of iron (Fe) doped tin oxide films, which have been deposited by spray pyrolysis technique. The doping level has changed from 0 to 10 wt% in solution ([Fe]/[Sn] ¼ 0e40 at% in solution). The thermoelectric response versus temperature difference has exhibited a nonlinear behavior, and the Seebeck coefficient has been calculated from its slope in temperature range of 300e500 K. The Hall effect and thermoelectric measurements have shown p-type conductivity in SnO2:Fe films with [Fe]/[Sn]  7.8 at%. In doping levels lower than 7.8 at%, SnO2:Fe films have been n-type with a negative thermoelectric coefficient. The Seebeck coefficient for SnO2:Fe films with 7.8 at% doping level has been obtained to be as high as þ1850 mV/K. The analysis of as-deposited samples with thicknesses w350 nm by X-ray diffraction (XRD) and scanning electron microscopy (SEM) has shown polycrystalline structure with clear characteristic peak of SnO2 cassiterite phase in all films. The optical transparency (T%) of SnO2:Fe films in visible spectra decreases from 90% to 75% and electrical resistivity (r) increases from 1.2  102 to 3  103 U cm for Fe-doping in the range 0e40 at%.  2008 Elsevier Masson SAS. All rights reserve

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