Fabrication and optical properties of core-shell structured spherical SiO{sub 2}.GdVO{sub 4}:Eu{sup 3+} phosphors via sol-gel process

Journal Article · Tue Aug 15 04:00:00 EDT 2006 · Journal of Solid State Chemistry

OSTI ID:20905426

Guangzhi, Li ^[1]; Zhenling, Wang ^[1]; Min, Yu ^[1]; Zewei, Quan ^[1]; Jun, Lin ^[1]

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1. Key laboratory of Rare Earth Chemistry and Physics, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

Europium-doped nanocrystalline GdVO{sub 4} phosphor layers were coated on the surface of preformed submicron silica spheres by sol-gel method. The resulted SiO{sub 2}.Gd{sub 0.95}Eu{sub 0.05}VO{sub 4} core-shell particles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (FESEM), energy-dispersive X-ray spectra (EDS), transmission electron microscopy (TEM), photoluminescence (PL) spectra, low voltage cathodoluminescence (CL), time resolved PL spectra and kinetic decays. The XRD results demonstrate that the Gd{sub 0.95}Eu{sub 0.05}VO{sub 4} layers begin to crystallize on the SiO{sub 2} spheres after annealing at 600 {sup d}eg. C and the crystallinity increases with raising the annealing temperature. The obtained core-shell phosphors have spherical shape, narrow size distribution (average size ca. 600 nm), non-agglomeration. The thickness of the Gd{sub 0.95}Eu{sub 0.05}VO{sub 4} shells on the SiO{sub 2} cores could be easily tailored by varying the number of deposition cycles (50 nm for four deposition cycles). PL and CL show that the emissions are dominated by {sup 5}D{sub 0}-{sup 7}F{sub 2} transition of Eu{sup 3+} (618 nm, red). The PL and CL intensities of Eu{sup 3+} increase with increasing the annealing temperature and the number of coating cycles. The optimum concentration for Eu{sup 3+} was determined to be 5 mol% of Gd{sup 3+} in GdVO{sub 4} host. - Graphical abstract: Spherical SiO{sub 2} particles have been coated with GdVO{sub 4}:Eu phosphor layers by a Pechini sol-gel process, which show the characteristic red emission of Eu{sup 3+}.

• OSTI ID: 20905426
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 8 Vol. 179; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANNEALING
CATHODOLUMINESCENCE
DEPOSITION
EUROPIUM IONS
GADOLINIUM COMPOUNDS
GADOLINIUM IONS
LAYERS
PHOSPHORS
PHOTOLUMINESCENCE
SILICON OXIDES
SOL-GEL PROCESS
SPHERICAL CONFIGURATION
TRANSMISSION ELECTRON MICROSCOPY
VANADATES
X-RAY DIFFRACTION