Investigation of structural and optical properties of pure and zinc doped CuO nanoparticles

Abstract

In the present study effect of Zn doping on the structural and optical properties of CuO nanoparticles has been investigated. The CuO nanoparticles doped with 0, 1 and 3 wt% Zinc oxide have been prepared by ball milling process for 24 hrs followed by heat treatment for 4 hrs at 500 °C. The structural properties have been investigated with the help of X-ray diffraction patterns, which reveals that all the samples contain monoclinic phase of the CuO along with hexagonal ZnO structure in case of doped samples. The lattice parameters and unit cell volume of the CuO nanoparticles show clear dependence on the dopant concentration. The crystallite size and micro-strain of the nanoparticle samples are evaluated using Williamson-Hall peak profile analysis. The Raman spectra are used to evaluate the vibrational properties of the CuO nanoparticles. The optical band energy of the samples has been evaluated from UV-Visible spectroscopy data and shows decreasing trend with increase of Zn doping concentration. The Urbach energy and Micro-strain values indicates that defect introduced by dopant into host matrix are responsible for observed band gap reduction. The presence of various types of defects and vacancies in our samples is confirmed from the Photoluminescence spectroscopy. It can be concluded that tuning of structural and optical properties is possible with the introduction of Zn into CuO lattice.