Novel red-emitting Eu3+, Sm3+ singly doped and co-doped Ca14Mg2(SiO4)8 phosphors were prepared by conventional solidstate reaction. Powder X-ray diffraction patterns were employed to confirm phase pttrity. Ca14Mg2...Novel red-emitting Eu3+, Sm3+ singly doped and co-doped Ca14Mg2(SiO4)8 phosphors were prepared by conventional solidstate reaction. Powder X-ray diffraction patterns were employed to confirm phase pttrity. Ca14Mg2(SiO4)8:Eu3+ phosphors exhibited intense red emission under 394 nm excitation and Ca14Mg2(SiO4)8:Sm3+ phosphors, excited at 405 nm, also showed strong red emitting at 602 nm. The concentration quenching mechanism of Cal4Mg2(SiOa)s:Eu3+ was dipole-dipole interaction, while that of CalnMg2(SiOn)8:Sm3+ was energy migration among nearest neighbor ions. The results indicated that Ca14Mg2(SiOn)8:Eu3+ and Ca14Mg2(SiOn)s:Sm3+ were promising red-emitting phosphors for WLEDs. Meanwhile, the effect of co-doping Sm3+ ions on photoluminescence properties of CalaMg2(SiO4)s:Eu3+ was studied and energy transfer from Sm3+ to Eu3+ was discovered in Eu3+, Sm3+ co-doped phosphors.展开更多
The Eu-doped SiO2-B2O3-NaF glass was prepared by sol-gel process, using tetraethoxy Silicane, boric acid and sodium fluoride as starting materials, 0.10 mol·L-1 EuCl3 solution as the dopant. The luminescent prope...The Eu-doped SiO2-B2O3-NaF glass was prepared by sol-gel process, using tetraethoxy Silicane, boric acid and sodium fluoride as starting materials, 0.10 mol·L-1 EuCl3 solution as the dopant. The luminescent properties of Eu3+ doped SiO2-B2O3-NaF phosphors were investigated. The phosphors showed prominent luminescence in pink, the strong emission of Eu3+ comes from electronic transition of 5D0-7F1(591 nm)and 5D0-7F2(615 nm),which derived from two transition modes of magnetic-dipole and electric-dipole .The peak intensity of 591nm in SiO2-B2O3-NaF matrix is much stronger than it in the other matrixes, it means that SiO2-B2O3-NaF has sensitization on the transition of 5D0-7F1 (Eu3+). If there are broad bonds in the range of 275~380 nm in the excitation spectrum of Eu3+ -doped SiO2-B2O3-NaF glass, the emission peak intensity should be intensified. It is because the electron migration CT band of O2--Eu3+. For all Eu3+ concentrations used, the investigation found that when the mass of fraction got to 29.19×10-3, the luminescence intensity reached the summit. And there is a phenomenon of concentration quenching. Investigation with the same concentration of Eu3+ at different annealed temperature, we found that the sample annealed at 400 ℃, the luminescence intensity achieved its maximum value, and Eu3+ in this matrix had a phenomenon of temperature quenching. The structural characterization of these luminescent materials was carried by used XRD and TEM. The result showed that the phosphor was in amorphous phase.展开更多
An improved sol-gel method was employed to prepare Eu3+ ions doped SiO2-Y2O3 nanocomposites.Systematic study was carried out on the effect of post-annealing treatment on photoluminescence(PL) properties of the samples...An improved sol-gel method was employed to prepare Eu3+ ions doped SiO2-Y2O3 nanocomposites.Systematic study was carried out on the effect of post-annealing treatment on photoluminescence(PL) properties of the samples under various europium ions doping concentrations.X-ray diffraction(XRD) patterns indicated that the samples showed an amorphous matrix structure,and the scanning electron microscopy(SEM) pictures showed that the samples presented a nano size(from 21 to 42 nm) granular-stack structure after hi...展开更多
基金supported by the Hong Kong,Macao and Taiwan Science and Technology Cooperation Special Project of Ministry of Science and Technology of China(2014DFT10310)the National Basic Research Program of China(973 Program,2014CB643801)the National Natural Science Foundation of China(51402288,51102229,21401184)
摘要Novel red-emitting Eu3+, Sm3+ singly doped and co-doped Ca14Mg2(SiO4)8 phosphors were prepared by conventional solidstate reaction. Powder X-ray diffraction patterns were employed to confirm phase pttrity. Ca14Mg2(SiO4)8:Eu3+ phosphors exhibited intense red emission under 394 nm excitation and Ca14Mg2(SiO4)8:Sm3+ phosphors, excited at 405 nm, also showed strong red emitting at 602 nm. The concentration quenching mechanism of Cal4Mg2(SiOa)s:Eu3+ was dipole-dipole interaction, while that of CalnMg2(SiOn)8:Sm3+ was energy migration among nearest neighbor ions. The results indicated that Ca14Mg2(SiOn)8:Eu3+ and Ca14Mg2(SiOn)s:Sm3+ were promising red-emitting phosphors for WLEDs. Meanwhile, the effect of co-doping Sm3+ ions on photoluminescence properties of CalaMg2(SiO4)s:Eu3+ was studied and energy transfer from Sm3+ to Eu3+ was discovered in Eu3+, Sm3+ co-doped phosphors.
摘要The Eu-doped SiO2-B2O3-NaF glass was prepared by sol-gel process, using tetraethoxy Silicane, boric acid and sodium fluoride as starting materials, 0.10 mol·L-1 EuCl3 solution as the dopant. The luminescent properties of Eu3+ doped SiO2-B2O3-NaF phosphors were investigated. The phosphors showed prominent luminescence in pink, the strong emission of Eu3+ comes from electronic transition of 5D0-7F1(591 nm)and 5D0-7F2(615 nm),which derived from two transition modes of magnetic-dipole and electric-dipole .The peak intensity of 591nm in SiO2-B2O3-NaF matrix is much stronger than it in the other matrixes, it means that SiO2-B2O3-NaF has sensitization on the transition of 5D0-7F1 (Eu3+). If there are broad bonds in the range of 275~380 nm in the excitation spectrum of Eu3+ -doped SiO2-B2O3-NaF glass, the emission peak intensity should be intensified. It is because the electron migration CT band of O2--Eu3+. For all Eu3+ concentrations used, the investigation found that when the mass of fraction got to 29.19×10-3, the luminescence intensity reached the summit. And there is a phenomenon of concentration quenching. Investigation with the same concentration of Eu3+ at different annealed temperature, we found that the sample annealed at 400 ℃, the luminescence intensity achieved its maximum value, and Eu3+ in this matrix had a phenomenon of temperature quenching. The structural characterization of these luminescent materials was carried by used XRD and TEM. The result showed that the phosphor was in amorphous phase.
基金supported by the Guangdong Province (2007-173)Jiangmen City (2009-217)
摘要An improved sol-gel method was employed to prepare Eu3+ ions doped SiO2-Y2O3 nanocomposites.Systematic study was carried out on the effect of post-annealing treatment on photoluminescence(PL) properties of the samples under various europium ions doping concentrations.X-ray diffraction(XRD) patterns indicated that the samples showed an amorphous matrix structure,and the scanning electron microscopy(SEM) pictures showed that the samples presented a nano size(from 21 to 42 nm) granular-stack structure after hi...