Silica Supported Submicron SiO2@Y2SiO5:Eu3+ and SiO2@Y2SiO5:Ce3+/Tb3+ Spherical Particles with a Core–Shell Structure: Sol–Gel Synthesis and Characterization

X1‐Y2SiO5:Eu3+ and X1‐Y2SiO5:Ce3+ and/or Tb3+ phosphor layers have been coated on nonaggregated, monodisperse, submicron spherical SiO2 particles by a sol–gel process, followed by surface reaction at high temperature (1000 °C), to give core/shell structured SiO2@Y2SiO5:Eu3+ and SiO2@Y2SiO5:Ce3+/Tb3+ particles. X‐ray diffraction (XRD), field emission scanning electron microscopy (FESEM), TEM, photoluminescence (PL), low voltage cathodoluminescence (CL), and time‐resolved PL spectra and lifetimes are used to characterize these materials. The XRD results indicate that X1‐Y2SiO5 layers have been successfully coated on the surface of SiO2 particles, as further verified by the FESEM and TEM images. The PL and CL studies suggest that SiO2@Y2SiO5:Eu3+, SiO2@Y2SiO5:Tb3+ (or Ce3+/Tb3+), and SiO2@Y2SiO5:Ce3+ core/shell particles exhibit red (Eu3+, 613 nm: 5D0–7F2), green (Tb3+, 542 nm: 5D4–7F5), or blue (Ce3+, 450 nm: 5d‐4f) luminescence, respectively. PL excitation, emission, and time‐resolved spectra demonstrate that there is an energy transfer from Ce3+ to Tb3+ in the SiO2@Y2SiO5:Ce3+,Tb3+ core/shell particles. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)