Fe 3 + -doped SnO 2 thin film Sol-gel dip coating Microstructural Optical and electrical properties a b s t r a c t Nanosized Fe 3 + -doped SnO 2 thin film was prepared by the sol-gel dip coating (SGDC) technique on quartz class substrate and sintered at 800 1C. The microstructures, surface morphology and optical properties of these films were then characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and optical absorption measurements, respectively. Electrical properties were analyzed, and resistivity, type and number of carrier concentration, Hall mobility measured as a function of Fe 3 + doping and temperature. The XRD spectrum shows the decrease in peak heights as a result of Fe 3 + -doping while SEM images reveal reduction in crystallite size with increase in Fe 3 + content. The optical studies showed a direct band gap reducing with increase in Fe 3 + -doping from 3.87 to 3.38 eV. From the electrical measurements, it was found that the resistivity initially increased with Fe 3 + -doping before reducing at higher doping level. Hall mobility measurements showed n-type conductivity at lower Fe 3 + -doping levels and p-type at higher levels. The increase in conductivity with temperature ascertained the semiconducting behavior of these films.