Significant impact of co-doping Eu-doped ZnO nanoparticles with Li on structural–optical properties relationship

ABSTRACT We describe here the structural evolution and optical properties of co-doping of Eu-doped ZnO nanoparticles with lithium synthesized by the sol-gel process. The characterization was carried out via X-ray diffraction (XRD), Fourier transmission infrared (FTIR), UV-Vis spectroscopy, and photoluminescence (PL) techniques. XRD confirmed hexagonal wurtzite phase of ZnO nanoparticles with crystallite size in the range of 22–61 nm. The band gap calculated from UV-vis spectra was in the range of 3.30–3.26 eV for undoped and Li and Eu co-doped ZnO nanoparticles, respectively, while photoluminescence study indicated that Li in Eu-ZnO affected the PL emission intensity, which was attributed to defects present in the crystal lattice. The field emission scanning electron microscopy (FESEM) images revealed the diverse morphology containing, spherical, tri-, tetra-, penta- and hexagonal rod-like nanostructures.