Microstructure and optical properties of Fe-doped ZnO thin films deposited by spray pyrolysis

In the present study, Fe-doped ZnO (Zn1−xFexO) thin films were deposited by simple chemical spray pyrolysis technique on glass substrates at substrate temperature of 300 °C. The effect of Fe-doping concentration on the structural, morphological and optical properties of deposited films was studied. The X-ray diffraction (XRD) analyses indicates that all the obtained samples have a hexagonal wurtzite crystal structure without any secondary phases. The atomic force microscopy (AFM) images show that the morphology features changes with the increase of Fe-doping concentration and a denser microstructure and smoother surface obtained. The Fourier transform infrared (FTIR) spectra shows the presence of the stretching vibration mode of ZnO, functional groups, chemical bonding and iron in the doped ZnO thin films. Optical studies indicate that the absorption edge of deposited film shifted towards higher-wavelength direction and their optical band-gaps are decreased with the increase of Fe-doping concentration.