Effect of (Co, Fe, Ni) doping on structural, optical and electrical properties of sprayed SnO2 thin film

Pure and (Co, Fe, Ni)-doped tin oxide (SnO2) thin film were deposited on glass substrates kept at 400 °C by spray pyrolysis technique. The effect of (Co, Fe, Ni) doping on the structural, morphological, optical and electrical properties of SnO2 thin films was investigated. First, X-ray diffraction (XRD) study revealed that all the pure and (Co, Fe, Ni)-doped SnO2 films were polycrystalline with the tetragonal rutile structure. The scanning electron microscopy (SEM) showed a smooth and dense surface with large grain sizes for doped films. Second, the optical analysis by means of the transmittance revealed the films depend on the type of the dopant and the doping promotes the decrease of the estimated band gap. Finally, the I-V curves revealed that the undoped and (Co, Fe, and Ni)-doped SnO2 thin films obey ohms law and the resistivity decreased with doping.