Sol-gel Synthesis and Characterization of Zn[sub 2]SiO[sub 4]:Mn@SiO[sub 2] Spherical Core-Shell Particles

Abstract

The synthesis and characterization of phosphor layers on spherical silica spheres, i.e., core-shell particles of are described in this paper. First, monodisperse silica spheres with an average size around have been obtained via the Stöber method by the hydrolysis and condensation of tetraethoxysilane under base condition (using as the catalyst). Second, the silica spheres are coated with phosphor layers by a sol-gel process. The resulting core-shell particles are characterized by X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscope, energy-dispersive X-ray spectroscopy, transmission electron microscopy, photoluminescence, low-voltage cathodoluminescence, as well as kinetic decay. The results confirm that the -annealed sample consists of crystalline shells and amorphous cores with spherical morphology and narrow size distribution. The particles show the green emission at corresponding to transition of under the excitation of UV , vacuum UV , and electron-beams . The luminescence intensity has been studied as a function of coating number, accelerating voltage, and filament current, respectively.