Optoelectronic properties of Mg and Cu co-doped ZnO nanostructure

Abstract

In this work, both pure and Mg-Cu co-doped zinc oxide thin films are prepared by sol-gel spin coating technique. Microscopic glass substrates are used for the synthesis of thin films. The thin films are examined by X-ray spectroscopy (XRD), photoluminescence spectroscopy (PL), scanning electron microscopy (SEM), ultraviolet-visible spectroscopy (UV-Vis), and energy dispersive X-ray analysis (EDX). The XRD reveals the hexagonal wurtzite phase of the films. The observed grain size is 23.34 nm to 15.94 nm for pure and Mg-Cu co-doped ZnO respectively. The SEM image shows an increase in grain size and a smoothing of the surface with Mg-Cu co-doping. The presence of Mg and Cu in the ZnO nanofilm is confirmed by EDX analysis. UV analysis shows an increase in percent transmittance with doping. The Tauc relation is used to estimate the band gap of the samples, and a significant shift in the band gap is observed. The photoluminescence diagram shows greater emission and surface defects with doping. The visible spectrum is completely covered by the low- level emission.