Synthesis and photoluminescence properties of Ce3+ and Eu2+-activated Ca7Mg(SiO4)4 phosphors for solid state lighting.
Ce(3+) and Eu(2+) singly doped and Ce(3+)/Eu(2+)-codoped Ca(7)Mg(SiO(4))(4) phosphors are synthesized by the conventional solid state reaction. The Ce(3+) activated sample exhibits intense blue emission under 350 nm excitation, the composition-optimized Ca(7)Mg(SiO(4))(4) : 4%Ce(3+) shows better color purity than the commercial blue phosphor, BaMgAl(10)O(17) : Eu(2+) (BAM : Eu(2+)) and exhibits superior external quantum efficiency (65%). The Ca(7)Mg(SiO(4))(4) : Eu(2+) 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 Ca(7)Mg(SiO(4))(4) : Eu(2+) 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 Ce(3+) to Eu(2+) 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 quenching method.
State key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China.
Yongchao
Y
Jia
Hui
H
Qiao
Yuhua
Y
Zheng
Ning
N
Guo
Hongpeng
H
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