The effects of gadolinium doping on the structural, morphological, optical, and photoluminescence properties of zinc oxide nanoparticles prepared by co-precipitation method

Abstract

Pure and gadolinium (Gd)-doped zinc oxide (ZnO) nanoparticles were prepared by co-precipitation method. The EDS analysis confirmed the presence of Gd³⁺ ions in ZnO lattice. The X-ray diffraction measurement indicated the formation of hexagonal wurtzite structure for both pure and Gd-doped ZnO nanoparticles. The structural parameters of nanoparticles such as lattice constant, crystallite size, dislocation density, micro strain and other lattice parameters were calculated from XRD data. FESEM images of nanoparticles showed that the grain morphology of nanoparticles tends to hexagonal form by introducing Gd³⁺ ions into the ZnO lattice. The presence of functional groups and chemical bonding attributed to ZnO was confirmed by FT-IR measurement. The optical properties of nanoparticles were investigated by UV–Vis spectroscopy. The UV–Vis absorbance spectra, for Gd-doped samples, illustrated a blue shift by increasing Gd concentration. Also, the band gap of nanoparticles increased by increasing Gd concentration. The photoluminescence spectra of Gd-doped nanoparticles showed that the intensity of green luminescence increases by substitution of Gd³⁺ ions into the ZnO lattice attributed to the oxygen vacancies.