Structural and luminescence properties of Y2O3:Eu3+ core-shell nanoparticles

Monodisperse Y2O3, Y2O3:Eu3+ and (Y2O3-La2O3):Eu3+ spherical nanoparticles were synthesized as well as Y2O3@Eu3+, Y2O3@(Eu3+, La3+) and Au@SiO2@Y2O3:Eu3+ core-shell structured nanoparticles, using Y2O3 and Au@SiO2 cores. Monodisperse spheres and shells were prepared by homogeneous precipitation method. Transmission electron microscopy confirmed that spherical particles were obtained and the samples were also measured with XPS. The optical properties of the prepared samples were investigated and compared to each other. The photoluminescence spectra show that the spherical Y2O3:Eu3+ and Y2O3@Eu3+ core-shell nanoparticles have similar emission spectra. However the emission spectra of the Y2O3@(Eu3+, La3+) and the Au@SiO2@Y2O3:Eu3+ core-shell nanoparticles differ from the other spectra. Using La3+ ion as codopant a new emission peak emerges. Also with the use of different cores in the core-shell nanoparticles the emission spectra can be altered. Eu-151 Mossbauer spectra of the spherical Y2O3:Eu3+ and Y2O3@Eu3+ core-shell nanoparticles show different Eu microenvironments and confirm the structure of these nanoparticles. (C) 2012 Elsevier B.V. All rights reserved.