Article

Synthesis and photoluminescence properties of Ce3+ and Eu2+-activated Ca7Mg(SiO4)4 phosphors for solid state lighting

Physical Chemistry Chemical Physics (Impact Factor: 4.2). 02/2012; 14(10):3537-3542. DOI: 10.1039/C2CP23343F

ABSTRACT Ce3+ and Eu2+ singly doped and Ce3+/Eu2+-codoped Ca7Mg(SiO4)4 phosphors are synthesized by the conventional solid state reaction. The Ce3+ activated sample exhibits intense blue emission under 350 nm excitation, the composition-optimized Ca7Mg(SiO4)4 : 4%Ce3+ shows better color purity than the commercial blue phosphor, BaMgAl10O17 : Eu2+ (BAM : Eu2+) and exhibits superior external quantum efficiency (65%). The Ca7Mg(SiO4)4 : Eu2+ powder shows a broad emission band in the wavelength range of 400-600 nm with a maximum at about 500 nm. The strong excitation bands of the Ca7Mg(SiO4)4 : Eu2+ in the wavelength range of 250-450 nm are favorable properties for applications as light-emitting-diode conversion phosphors. Furthermore, the energy transfer from the Ce3+ to Eu2+ ions is observed in the codoped samples, the resonance-type energy transfer is determined to be due to the dipole-dipole interaction mechanism and the critical distance is obtained through the spectral overlap approach and concentration quenc

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