Synthesis and Characterization of ZnO/Er2O3/rGO Nanocomposite and its Dielectric Properties

Abstract

and Er2O3 are wide bandgap semiconductors and show low leakage current; therefore, they can be considered suitable dielectric materials for applications of energy storage devices. However, erbium doped ZnO show a decrease in dielectric properties than pure ZnO. To study the effect of erbium oxide concentration on the dielectric properties of ZnO/Er2O3 nanocomposites two samples with different ratios of precursors (zinc nitrate: erbium nitrate); ZE1 (1:0.5) and ZE2 (1:1) were synthesized and characterized via various characterization techniques. The study of the effect of rGO on ZnO/Er2O3 to enhance its dielectric properties was done by synthesizing two samples ZE1-rGO (1:0.025) and ZE2- rGO(1:0.025), using the as-synthesized ZE1 and ZE2 nanocomposites. The ratio of rGO was kept constant in both samples for optimization. All the samples were characterized by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning electron microscopy (SEM), Diffuse reflectance spectroscopy (DRS), Energy Dispersive Spectroscopy (EDS), and Impedance Spectroscopy (IS). XRD patterns corresponding to respective reflection planes confirmed the successful synthesis of all samples along with the wurtzite hexagonal crystal structure and cubic crystal structure of ZnO and Er2O3, respectively. FTIR spectrum revealed the characteristics bands for each nanocomposite. SEM analysis showed an increase in grains with the increased concentration of erbium oxide and the successful deposition of ZE1 and ZE2 on rGO. The bandgap of each sample was found by plotting the Kubelka-Munk function vs Energy. Dielectric constant, dielectric loss, and ac conductivity properties were increased with the addition of rGO to ZnO/Er2O3 nanocomposites.