Effect of (Ce, Dy) co-doping on the microstructural, optical and photoluminescence characteristics of solution combustion synthesized ZnO nanoparticles.

Abstract

Solution combustion synthesized ZnO nanoparticles with Ce, Dy doped and co-doped with varying dopant concentrations were characterized for their microstructural, optical and photoluminescence characteristics. The synthesized nanoparticles have been found to match the standard hexagonal wurtzite structure of ZnO. The lattice fringes in the high-resolution transmission electron micrographs and the bright spotty rings in the selected area electron diffraction pattern authenticate the high crystallinity of the nanoparticles. The diffuse reflectance spectroscopy provides the energy bandgap for the undoped ZnO to be 3.18 eV, decreasing upon doping and co-doping. A sharp narrow UV emission peak at ~ 398 nm originating from the excitonic recombination is found in the PL spectra of the nanoparticles. The visible emission peaks in the PL spectra are assigned to f-d and f-f electron transitions of Ce3+ and Dy3+ ions, respectively, in addition to different native defects in ZnO. The visible emissions (blue, yellow and red) have been found to improve upon (Ce, Dy) co-doping, and therefore (Ce, Dy) co-doped ZnO nanoparticles can be considered as a promising luminescent material for the development of energy-saving light sources.