Synthesis and photoluminescence properties of La2Zr2O7:Eu3+@YBO3 core@shell nanoparticles.

Novel heterostructured La2Zr2O7:Eu(3+)@YBO3 core@shell nanoparticles (NPs) composed of a trivalent europium doped lanthanum zirconate (La2Zr2O7:Eu(3+)) core and yttrium orthoborate (YBO3) shell are reported in this paper for the first time. X-ray diffraction, Fourier transform infrared spectroscopy, scanning and transmission electron microscopies, and x-ray photoelectron spectroscopy were employed to confirm the formation of the heterostructured core@shell NPs. Luminescent enhancement was observed after the La2Zr2O7:Eu(3+) core NPs were coated with the thin YBO3 shells under 405 nm excitation. Based on optical transition property analysis and fluorescent decay measurement, the reduction of non-radiative transition rate is possibly responsible for the luminescent enhancement. Moreover, an improvement of the symmetry around the Eu(3+) ions in the La2Zr2O7:Eu(3+) core NPs was found after the YBO3 shell coating.