The Effect of Sn/Si Dopant on Optical and Structural Properties of Nanostructured Zinc Oxide Thin Films

In this study, preparation of Sn and Si co-doped (0-3 mol% Sn and Si) ZnO dip-coated thin films on a glass substrate via the sol-gel process have been investigated. The effects of Sn and Si content on the structural and optical properties of applied thin films have been studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-vis spectroscopy. XRD patterns showed a decrease in peak intensities of zinc oxide crystalline phase which is the result of increasing the Sn and Si co-dopant. The optical band gaps of the films were calculated. This suggests that the absorption edge shifts to higher wavelengths with Sn and Si dopant. The optical absorption spectrum indicates that the ZnO thin films have a direct band gap of 3.41 eV. But the optical band gap of the doped ZnO was found to be 2.64-3.35 eV.