Optical constants and dispersion energy parameters of Zn-doped TiO2 thin films prepared by spray pyrolysis technique

Abstract

The present work describes the deposition and investigation of structural and optical characteristics of bare and doped TiO2 thin films. The TiO2 products are obtained through simple and cost effective spray pyrolysis technique (SPT) using titanium (IV) butoxide as Ti precursor. The impact of Zn doping on the crystal structure and phase formation is studied by X-ray diffraction (XRD) analysis. The formation of anatase phase relative to pure TiO2 along with preferred orientation along the [101] direction is confirmed with the help of XRD analysis. Zn doping into TiO2 lattice network leads to an identical diffraction pattern. A deterioration of crystallinity is obtained in crystallite size employing the numerous methods such as Scherrer method, Williamson–Hall, Halder–Wagner and Wagner–Agua analysis in accordance with Zn. In addition, absorbance results obtained from UV–vis spectroscopy has been exerted to examine the optical characteristics. It is noted that the dopant introduction has an impact on the optical properties and the direct band gap value obtained from Tauc relation exhibits a red shift with Zn content. The influence of the Zn doping elements on the optical constants of TiO2 product has been investigated. The dielectric constants, dispersion parameters, loss factor and distribution of volume and surface energy loss of the TiO2 products have been computed as well. The as-prepared nanostructured Zn-doped TiO2 thin films can be used as potential candidates for different optoelectronic devices