Sol-gel synthesis and photoluminescence properties of BaSO4/Y2O3:Eu3+ core-shell submicrospheres

Europium-doped nanocrystalline Y2O3 phosphor layers were coated on the surface of preformed submicron BaSO4 spheres via the sol-gel process. The obtained BaSO4/Y2O3:Eu3+ core-shell phosphors were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and photoluminescence spectra. The results showed that the obtained BaSO4/Y2O3:Eu3+ core-shell phosphors consisted of well-dispersed submicron spherical particles with narrow size distribution and non-agglomeration. TEM and EDS results showed that BaSO4 particles were well coated with the shell of Y2O3:Eu3+. XRD result demonstrated that no reaction occurred between the BaSO4 cores and the Y2O3:Eu3+ shells even after annealing at 1200 °C. The BaSO4/Y2O3:Eu3+ core-shell particles showed a red emission corresponding to 5D0–7F2 of Eu3+ under the excitation of ultraviolet.