YAl3 （BO3）4： Eu^3＋ phosphors were prepared by the conventional solid state reaction. The phase structure and morphology were investigated by X-ray diffraction （XRD） and scanning electron microscope （SEM）. Dopi...YAl3 （BO3）4： Eu^3＋ phosphors were prepared by the conventional solid state reaction. The phase structure and morphology were investigated by X-ray diffraction （XRD） and scanning electron microscope （SEM）. Doping YAl3（BO3）4： Eu^3＋ phosphors with concentration of Eu^3＋ ions of 0, 2, 5, 8 and 10 mol% were studied and their luminescent properties at room temperature were discussed. The excitation spectrum of Y0.95Eu0.05Al3（BO3）4 was composed of a broad band centered at about 252 nm and a group of lines in the longer wavelength region. In the emission spectra, the peak wavelength was about 614 nm under a 252 nm UV excitation. The optimal doping concentration of Eu^3＋ ions in YAl3（BO3）4： Eu^3＋ phosphors was 8 mol%.展开更多
The photoluminescence(PL) properties of Ca4YO(BO3)3 doped with Bi3+,Dy3+,and Pr3+ ions were investigated.These compounds were prepared using a typical solid-state reaction.The excitation and emission spectra were meas...The photoluminescence(PL) properties of Ca4YO(BO3)3 doped with Bi3+,Dy3+,and Pr3+ ions were investigated.These compounds were prepared using a typical solid-state reaction.The excitation and emission spectra were measured using a spectrofluorometer.For Ca4YO(BO3)3:Bi3+,the excitation spectrum showed the bands at about 228,309,and 370 nm which correspond to the 1S0→1P1 transition and the 1S0→3P1 transition of Bi3+ ions.The emission band at 390 nm corresponded to the 3P1→1S0 transition of Bi3+ ions.For Ca4YO(...展开更多
采用高温固相法合成了La_(2)MgTiO_(6)∶Mn^(4+)、La_(2)MgTiO_(6)∶Pr^(3+)、La_(2)MgTiO_(6)∶Pr^(3+),Mn^(4+)单掺杂和双掺杂荧光粉,并通过X射线衍射、扫描电镜、荧光光谱等测试方法对荧光粉的物相结构、形貌和发光特性进行了表征及...采用高温固相法合成了La_(2)MgTiO_(6)∶Mn^(4+)、La_(2)MgTiO_(6)∶Pr^(3+)、La_(2)MgTiO_(6)∶Pr^(3+),Mn^(4+)单掺杂和双掺杂荧光粉,并通过X射线衍射、扫描电镜、荧光光谱等测试方法对荧光粉的物相结构、形貌和发光特性进行了表征及分析。结果表明:成功合成了La_(2)MgTiO_(6)∶Mn^(4+)、La_(2)MgTiO_(6)∶Pr^(3+)、La_(2)MgTiO_(6)∶Pr^(3+),Mn^(4+)荧光粉且均为纯相;样品的粒径为1~2μm;La_(2)MgTiO_(6)∶Mn^(4+)在650~750 nm的红光发射是来自Mn^(4+)的2 E 1→4 A 2跃迁,La_(2)MgTiO_(6)∶Pr^(3+)在红光区域600~660 nm具有强烈的发射,归属为Pr^(3+)的3 P 0→3 H 6和3 P 0→3 F 2跃迁。当Mn^(4+)与Pr^(3+)共同掺杂于La_(2)MgTiO_(6)时,来自Mn^(4+)、Pr^(3+)不同波段的红光发射使荧光粉的发射光谱与植物光敏色素P r与P fr吸收光谱的重叠程度大幅增加,表明Mn^(4+)、Pr^(3+)共掺有效拓宽了La_(2)MgTiO_(6)荧光粉的红光发射区域,更符合植物照明的需求,在LED植物照明领域具有更明显的潜在应用价值。展开更多
Ultrafine Y0.95–xGdxEu0.05Al3(BO3)4 phosphors with different Gd3+ concentrations were prepared by a solution combustion method, and characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM). Resu...Ultrafine Y0.95–xGdxEu0.05Al3(BO3)4 phosphors with different Gd3+ concentrations were prepared by a solution combustion method, and characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM). Results showed that the pure phase of YAl3(BO3)4 was obtained at 1000 oC and the prepared particle size varied with calcining temperatures. Photoluminescence spectra indicated that the dominant emission peak was observed at 612 nm due to the 5D0→7F2 transition of Eu3+. The luminescence intensity of ...展开更多
Novel red phosphors,Li2Sr1-1.5xSiO4：xPr3＋（x=0.002,0.003,0.004,0.005,0.006 and 0.008）,were synthesized by conventional solid state reaction and the luminescent properties were investigated.The as-prepared phosphors...Novel red phosphors,Li2Sr1-1.5xSiO4：xPr3＋（x=0.002,0.003,0.004,0.005,0.006 and 0.008）,were synthesized by conventional solid state reaction and the luminescent properties were investigated.The as-prepared phosphors showed red emission at 610 nm under excitation of blue light at 452 nm,indicating that they were promising candidates for red phosphors in the fabrication of white LEDs via blue LED chips.Their excitation bands at 452,476 and 487 nm were attributed to transitions of 3H4→3P2,3H4→3P1＋1I6,3H4→3P0 of Pr3＋ ion.The red emissions at 606 and 610 nm were originated from the 3P0-3H6 and 1D2-3H4 transitions of Pr3＋.The optimum doping concentration of Pr3＋ in Li2Sr1-1.5xSiO4：xPr3＋ was determined to be x=0.004.With the concentration of Pr3＋ over x=0.004,the fluorescence intensity of Li2Sr1-1.5xSiO4：xPr3＋ decreased,indicating the concentration quenching occurred.展开更多
Red phosphors, Li2Sr0.996 Si O4： Pr3＋0.004, with different hydrothermal conditions were prepared via hydrothermal synthesis and then heat-treatment. The chemical structures of the phosphors were identified with X-ra...Red phosphors, Li2Sr0.996 Si O4： Pr3＋0.004, with different hydrothermal conditions were prepared via hydrothermal synthesis and then heat-treatment. The chemical structures of the phosphors were identified with X-ray diffraction（XRD）. Surface morphological features were observed by scanning electron microscopic（SEM） investigation. Spectra of excitation and emission for the phosphors were also obtained by a spectrophotometer. Results showed that the optimum conditions were as follows： p H value of solution was 1–2, reaction temperature was at 180 oC for 24 h. The as-prepared phosphors exhibited two excitation dominant peaks at 451 and 486 nm, attributed to transitions of 3H4→3P2 and 3H4→3P0 of Pr3＋, respectively. A narrow emission peak at 610 nm corresponded to the energy level transition of 3P0→3H6 of Pr3＋ under excitation of light at 451 nm, which indicated promising candidate red phosphors for blue LED chips.展开更多
文摘YAl3 （BO3）4： Eu^3＋ phosphors were prepared by the conventional solid state reaction. The phase structure and morphology were investigated by X-ray diffraction （XRD） and scanning electron microscope （SEM）. Doping YAl3（BO3）4： Eu^3＋ phosphors with concentration of Eu^3＋ ions of 0, 2, 5, 8 and 10 mol% were studied and their luminescent properties at room temperature were discussed. The excitation spectrum of Y0.95Eu0.05Al3（BO3）4 was composed of a broad band centered at about 252 nm and a group of lines in the longer wavelength region. In the emission spectra, the peak wavelength was about 614 nm under a 252 nm UV excitation. The optimal doping concentration of Eu^3＋ ions in YAl3（BO3）4： Eu^3＋ phosphors was 8 mol%.
基金supported by Scientific Research Foundation for Returned Scholars of Ministry of Education of China (20071108)
文摘The photoluminescence(PL) properties of Ca4YO(BO3)3 doped with Bi3+,Dy3+,and Pr3+ ions were investigated.These compounds were prepared using a typical solid-state reaction.The excitation and emission spectra were measured using a spectrofluorometer.For Ca4YO(BO3)3:Bi3+,the excitation spectrum showed the bands at about 228,309,and 370 nm which correspond to the 1S0→1P1 transition and the 1S0→3P1 transition of Bi3+ ions.The emission band at 390 nm corresponded to the 3P1→1S0 transition of Bi3+ ions.For Ca4YO(...
文摘采用高温固相法合成了La_(2)MgTiO_(6)∶Mn^(4+)、La_(2)MgTiO_(6)∶Pr^(3+)、La_(2)MgTiO_(6)∶Pr^(3+),Mn^(4+)单掺杂和双掺杂荧光粉,并通过X射线衍射、扫描电镜、荧光光谱等测试方法对荧光粉的物相结构、形貌和发光特性进行了表征及分析。结果表明:成功合成了La_(2)MgTiO_(6)∶Mn^(4+)、La_(2)MgTiO_(6)∶Pr^(3+)、La_(2)MgTiO_(6)∶Pr^(3+),Mn^(4+)荧光粉且均为纯相;样品的粒径为1~2μm;La_(2)MgTiO_(6)∶Mn^(4+)在650~750 nm的红光发射是来自Mn^(4+)的2 E 1→4 A 2跃迁,La_(2)MgTiO_(6)∶Pr^(3+)在红光区域600~660 nm具有强烈的发射,归属为Pr^(3+)的3 P 0→3 H 6和3 P 0→3 F 2跃迁。当Mn^(4+)与Pr^(3+)共同掺杂于La_(2)MgTiO_(6)时,来自Mn^(4+)、Pr^(3+)不同波段的红光发射使荧光粉的发射光谱与植物光敏色素P r与P fr吸收光谱的重叠程度大幅增加,表明Mn^(4+)、Pr^(3+)共掺有效拓宽了La_(2)MgTiO_(6)荧光粉的红光发射区域,更符合植物照明的需求,在LED植物照明领域具有更明显的潜在应用价值。
基金Project supported by the Fundamental Research Funds for the Central Universities and Natural Science Basic Research Plan in Shaanxi Province of China (2009JQ6009)
文摘Ultrafine Y0.95–xGdxEu0.05Al3(BO3)4 phosphors with different Gd3+ concentrations were prepared by a solution combustion method, and characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM). Results showed that the pure phase of YAl3(BO3)4 was obtained at 1000 oC and the prepared particle size varied with calcining temperatures. Photoluminescence spectra indicated that the dominant emission peak was observed at 612 nm due to the 5D0→7F2 transition of Eu3+. The luminescence intensity of ...
基金supported by the Program for Changjiang Scholars and Innovative Research Team in University(IRT0730)the Key Project of De-partment of Science and Technology of Jiangxi Province
文摘Novel red phosphors,Li2Sr1-1.5xSiO4：xPr3＋（x=0.002,0.003,0.004,0.005,0.006 and 0.008）,were synthesized by conventional solid state reaction and the luminescent properties were investigated.The as-prepared phosphors showed red emission at 610 nm under excitation of blue light at 452 nm,indicating that they were promising candidates for red phosphors in the fabrication of white LEDs via blue LED chips.Their excitation bands at 452,476 and 487 nm were attributed to transitions of 3H4→3P2,3H4→3P1＋1I6,3H4→3P0 of Pr3＋ ion.The red emissions at 606 and 610 nm were originated from the 3P0-3H6 and 1D2-3H4 transitions of Pr3＋.The optimum doping concentration of Pr3＋ in Li2Sr1-1.5xSiO4：xPr3＋ was determined to be x=0.004.With the concentration of Pr3＋ over x=0.004,the fluorescence intensity of Li2Sr1-1.5xSiO4：xPr3＋ decreased,indicating the concentration quenching occurred.
基金Project supported by the Fujian Provincial Key Project(2013H6020)
文摘Red phosphors, Li2Sr0.996 Si O4： Pr3＋0.004, with different hydrothermal conditions were prepared via hydrothermal synthesis and then heat-treatment. The chemical structures of the phosphors were identified with X-ray diffraction（XRD）. Surface morphological features were observed by scanning electron microscopic（SEM） investigation. Spectra of excitation and emission for the phosphors were also obtained by a spectrophotometer. Results showed that the optimum conditions were as follows： p H value of solution was 1–2, reaction temperature was at 180 oC for 24 h. The as-prepared phosphors exhibited two excitation dominant peaks at 451 and 486 nm, attributed to transitions of 3H4→3P2 and 3H4→3P0 of Pr3＋, respectively. A narrow emission peak at 610 nm corresponded to the energy level transition of 3P0→3H6 of Pr3＋ under excitation of light at 451 nm, which indicated promising candidate red phosphors for blue LED chips.
