论文部分内容阅读
SiO2@Y2MoO6∶Eu3+ core-shell phosphors were prepared by the sol-gel process.X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR),field emission scanning electron microscope(FESEM),energy-dispersive X-ray spectra(EDS),transmission electron microscope(TEM),photoluminescence(PL)spectra as well as kinetic decays were used to characterize the resulting SiO2@Y2MoO6∶Eu3+ core-shell phosphors.The XRD results demonstrate that the Y2MoO6∶Eu3+ layers on the SiO2 spheres begin to crystallize after annealed at 600℃ and the crystallinity increases with raising the annealing temperature.The obtained core-shell phosphors have perfect spherical shape with narrow size distribution(average size ca.640 nm),non-agglomeration,and smooth surface.The thickness of the Y2MoO6∶Eu3+ shells on the SiO2 cores could be easily tailored by varying the number of deposition cycles(70 nm for four deposition cycles).The Eu3+ shows a strong PL emission(dominated by 5D0-7F2 red emission at 614 nm)under the excitation of 347nm UV light.The PL intensity of Eu3+ increases with increasing the annealing temperature and the number of coating cycles.