Sub-Micrometer SiO2@ZnMoO4:Tb3+ Core-Shell Phosphors: Sol-Gel Synthesis and Characterization

Abstract

ZnMoO4:Tb3+ phosphor layers were grown on monodisperse SiO2 particles through a simple sol-gel method, resulting in the formation of core-shell structured SiO2@ZnMoO4:Tb3+ sub-microspheres. The resulting SiO2@ZnMoO4:Tb3+ core-shell particles were characterized by powder X-ray diffraction(XRD), field emission scanning electron microscopy(FESEM), transmission electron microscopy(TEM) and photoluminescence(PL). SEM and TEM analysis indicates that the obtained sub-microspheres have a uniform size distribution and obvious core-shell structure. SiO2@ZnMoO4:Tb3+ sub-microspheres show strong green emission under ultraviolet(275nm) illumination and the emission spectra are dominated by a 5D4→7F5 transition of Tb3+(543nm,green) from the ZnMoO4:Tb3+ shells. The optimum concentration for Tb3+ was determined to be 5 mol% of Zn2+ in ZnMoO4 host shells.