Spectroscopic, structural and morphological properties of spin coated Zn:TiO2 thin films

Abstract Herein we report on the spin coated thin films of Zn-doped TiO2 on glass substrates with various Zn concentrations (2 ‒8 at %). The structural, chemical, optical and morphological properties were investigated using X-ray diffraction (XRD), Raman spectroscopy, photoluminescence (PL), UV-Visible spectroscopy, X-ray Photoelectron Spectroscopy (XPS) and Field Emission Scanning Electron Microscopy (FESEM). Studies by XRD and Raman confirmed the existence of the anatase phase. With increasing Zn2+ concentration, the crystallite size was found to decrease. FESEM studies reveal the homogenous distribution of grains in the films. UV-Visible spectra showed higher light absorption with doping, and the bandgap decreased from 3.47 eV to 3.36 eV. The Urbach energy was found to increase on doping. XPS spectra revealed the successful incorporation of Zn2+ ion into TiO2 lattice.