Synthesis, Structural and Optical Characteristics of Vanadium Doped Cerium Dioxide Layers

Abstract

This research paper reports on spray pyrolysis deposited cerium dioxide thin films. Our study consists of investigating the effect of Vanadium (V) doping on structural and optical characteristics of cerium dioxide (CeO2) layers through several characterization techniques. X-ray diffraction (XRD) patterns helped to estimate the crystallite size (D), micro-strain (e), and dislocation density (δ). The crystallite size was found to decrease from 7 nm to 5 nm with the increase of V doping concentrations. The obtained dislocation density and micro-strain of the layers were found to be 1016 lines/m2 and 10-3, respectively. The micro-Raman results show the characteristic peak F2g of CeO2 at ~461 cm-1. The spectrum led to conclude that the peak intensity of the layers decreased with the increase in the V ratio. The atomic force micrograph showed a surface morphology transformation from spherical to flake upon doping. The surface roughness of the investigated thin layers was increased from 3.53 to 6.15 nm by increasing V doping proportions. The optical properties of the layers were studied in the wavelength range of 325–1000 nm. The overall transmittance of the layers was found to decrease with an increase in the V ratio. The results exhibit a slightly lower band-gap energy with the increase of V doping, from 3.19 eV to 3.08 eV. Optical parameters like refractive index, extinction coefficient, optical conductivity, the real and imaginary part of dielectric constant (er & ei) were estimated by using an UV-Visible spectrum.