Polycrystalline indium-doped ZnO thin films: preparation and characterization

Zinc oxide (ZnO) and indium-doped zinc oxide (IZO) thin films have been deposited onto glass substrates by the spray pyrolysis method. The variations of the structural, electrical and optical properties with the indium incorporation were investigated. The crystal structure and orientation of the ZnO and IZO thin films were investigated by XRD patterns. All the deposited films are polycrystalline in nature. The grain sizes were calculated almost 31-36 nm. Morphological characterization and compositions of the films were performed by SEM and EDX analyses, respectively. It was observed that the surface morphologies of the films are almost uniform particle size distribution for the films. The optical absorbance through the films was measured spectrophotometrically in the wavelength range 200–900 nm. The optical band gap, Urbach parameters and optical parameters were determined. The electrical resistivity was obtained by the Van der Pauw method in dark and under UV-illumination. The effect of the light on the films shows that the obtained thin films can be used as a photovoltaic material.