Effect of zinc doping on the structure and optical properties of iron oxide nanostructured films prepared by spray pyrolysis technique

In the current work, the effect of zinc doping on the structural and optical properties of iron oxide has been explored for optoelectronic applications. Undoped and different (2-10 wt%) Zn-doped iron oxide (Fe2O3/Zn) nanostructured films (nFs) were successfully prepared via spray pyrolysis technique. The structural, morphological, bonds vibrations and optical properties of the prepared films were examined using X-ray diffraction (XRD), scanning electron microscope (SEM), FT-IR and UV-Vis-NIR spectroscopy techniques, respectively. The XRD measurements reveal the formation of the rhombohedral hematite phase structure of iron oxide (alpha-Fe2O3) for all prepared films. The FT-IR spectra analysis exhibits the existence of absorption bands corresponded to the stretching and bending vibrations of Fe-O and O-Fe-O bonds, respectively. The UV-Vis-NIR measurements of the prepared samples indicate the significant effect of Zn doping on various optical properties of Fe2O3 films. The achieved optical bandgap of Fe2O3/Zn nFs is tuned from 2.38 eV (undoped Fe2O3) to 2.83 eV (10 wt% of Fe2O3/Zn). These findings are explained on the basis of the created localized energy levels and Burstein-Moss effect. As a novel result of this study, Fe2O3/Zn nFs are well-qualified for the use in modern optoelectronic applications.