Monodisperse spherical core-shell-structured phosphors obtained by functionalization of silica spheres with Y2O3:Eu3+ layers for field emission displays

Spherical SiO2 particles have been coated with Y2O3:Eu3+ phosphor layers (SiO2@Y2O3:Eu3+) by a Pechini sol-gel process. X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, photoluminescence, and cathodoluminescence spectra were utilized to characterize the SiO2@Y2O3:Eu3+ core-shell-structured phosphor particles. The obtained core-shell phosphors consist of well dispersed submicron spherical particles with narrow size distribution. The thickness of Y2O3:Eu3+ shell could be easily controlled by changing the number of deposition cycles (60nm for three deposition cycles). The SiO2@Y2O3:Eu3+ core-shell particles show a strong red emission corresponding to D05-F27 (611nm) of Eu3+ under the excitation of ultraviolet (250nm) and low-voltage electron beams (2–6kV), which have potential application for field emission displays.