The long afterglow fluorescent material of M1-3xAl2O4:Eu2+ x/Dy3+2x(M2+= Sr2+, Ca2+ and Ba2+) phosphors are successfully synthesized by calcining precursor obtained via co-precipitation method at 1300oC for 4 h with r...The long afterglow fluorescent material of M1-3xAl2O4:Eu2+ x/Dy3+2x(M2+= Sr2+, Ca2+ and Ba2+) phosphors are successfully synthesized by calcining precursor obtained via co-precipitation method at 1300oC for 4 h with reducing atmosphere (20% H2 and 80% N2). The phase evolution, morphology and afterglow fluorescent properties are systematically studied by the various instruments of XRD, FE-SEM, PLE/PL spectroscopy and fluorescence decay analysis. The PL spectra shows that the Sr1-3xAl2O4:Eu2+x/Dy3+ 2x phosphors display vivid green emission at s519 nm (4f65d1!4f7 transition of Eu2+) with monitoring of the maximum excitation wavelength at s334 nm (8S7=2!6IJ transition of Eu2+), among which the optimal concentration of Eu2+ and Dy3+ is 15 at.% and 30 at.%, respectively. The color coordinates and temperature of Sr1-3xAl2O4:Eu2+ x/Dy3+ 2x phosphors are approximately at (s0.27, s0.57) and s6700 K, respectively. On the above basis, the M0:55Al2O4:Eu2+ 0:15/Dy3+ 0:3 (M2+= Ca2+ and Ba2+) phosphors is obtained by the same method. The PL spectra of these phosphors shows the strongest blue emission at s440 nm and cyan emission at s499 nm under s334 nm wavelength excitation, respectively, which are blue shifted comparing to Sr1??3xAl2O4:Eu2+ x/Dy3+ 2x phosphors. The color coordinates and temperatures of M0:55Al2O4:Eu2+ 0:15/Dy3+ 0:3 (M2+= Ca2+ and Ba2+) phosphors are approximately at (s0.18, s0.09), s2000 K and (s0.18, s0.42), s11600 K, respectively. In this work, long afterglow materials of green, blue and cyan aluminates phosphors with excellent properties have been prepared, in order to obtain wide application in the field of night automatic lighting and display.展开更多
A highly intense green-emitting phosphor of Eu2＋-doped Sr4Al14O25 （SAE：Eu2＋） was synthesized by a solid state reaction. In this study, XRD, PL/PLE, QE, thermal stability and LED package tests are systematically c...A highly intense green-emitting phosphor of Eu2＋-doped Sr4Al14O25 （SAE：Eu2＋） was synthesized by a solid state reaction. In this study, XRD, PL/PLE, QE, thermal stability and LED package tests are systematically carried out and investigated. The optimized-composition of （Sro 92Eu0.08）4Al14025 exhibited a green emission peak at 497 nm under excitation wavelength of 400 nm, giving the chromaticity coordinates of （0.14, 0.35） with excellent quantum efficiency （98%） compared to those of other green-commodities, such as Ba2SiO4：Eu2＋ （90%） and BaMgAl10O17：EU2＋, Mn2＋ （92%）. The results demonstrated that SAE：Eu2＋ could be a potential candidate as the NUV-pumping phosphor for applications in light-emitting diodes （LEDs）.展开更多
Eu2＋ and （or） Eu3＋ doped Sr2SiO4 phosphors particles were synthesized by a conventional solid-state reaction technique, and their structural and optical properties were investigated. The X-ray diffraction （XRD） ...Eu2＋ and （or） Eu3＋ doped Sr2SiO4 phosphors particles were synthesized by a conventional solid-state reaction technique, and their structural and optical properties were investigated. The X-ray diffraction （XRD） results showed that the obtained phosphors were composed of orthorhombic α′-Sr2SiO4 and monoclinic β-Sr2SiO4 phase. When excited under 256 nm, Sr2SiO4：Eu3＋ phosphors showed intense emission in the red region. Sr2SiO4：Eu3＋ phosphors exhibited white emissions （x=0.30, y=0.40, Tc=6500 K） ranging from 425 to 650 nm when it was excited by near-ultraviolet （near-UV） light, indicating that Sr2SiOn：Eu2＋ was a good light-conversion phosphor candidate for near-UV chip.展开更多
基金the National Natural Science Foundation of China (No. 51602126)the National Key Research and Development Plan of China (No. 2016YFB0303505)+1 种基金China and University of Jinan Postdoctoral Science Foundation (No. 2017M622118 and XBH1716)the 111 Project of International Corporation on Advanced Cement-based Materials (D17001).
文摘The long afterglow fluorescent material of M1-3xAl2O4:Eu2+ x/Dy3+2x(M2+= Sr2+, Ca2+ and Ba2+) phosphors are successfully synthesized by calcining precursor obtained via co-precipitation method at 1300oC for 4 h with reducing atmosphere (20% H2 and 80% N2). The phase evolution, morphology and afterglow fluorescent properties are systematically studied by the various instruments of XRD, FE-SEM, PLE/PL spectroscopy and fluorescence decay analysis. The PL spectra shows that the Sr1-3xAl2O4:Eu2+x/Dy3+ 2x phosphors display vivid green emission at s519 nm (4f65d1!4f7 transition of Eu2+) with monitoring of the maximum excitation wavelength at s334 nm (8S7=2!6IJ transition of Eu2+), among which the optimal concentration of Eu2+ and Dy3+ is 15 at.% and 30 at.%, respectively. The color coordinates and temperature of Sr1-3xAl2O4:Eu2+ x/Dy3+ 2x phosphors are approximately at (s0.27, s0.57) and s6700 K, respectively. On the above basis, the M0:55Al2O4:Eu2+ 0:15/Dy3+ 0:3 (M2+= Ca2+ and Ba2+) phosphors is obtained by the same method. The PL spectra of these phosphors shows the strongest blue emission at s440 nm and cyan emission at s499 nm under s334 nm wavelength excitation, respectively, which are blue shifted comparing to Sr1??3xAl2O4:Eu2+ x/Dy3+ 2x phosphors. The color coordinates and temperatures of M0:55Al2O4:Eu2+ 0:15/Dy3+ 0:3 (M2+= Ca2+ and Ba2+) phosphors are approximately at (s0.18, s0.09), s2000 K and (s0.18, s0.42), s11600 K, respectively. In this work, long afterglow materials of green, blue and cyan aluminates phosphors with excellent properties have been prepared, in order to obtain wide application in the field of night automatic lighting and display.
文摘A highly intense green-emitting phosphor of Eu2＋-doped Sr4Al14O25 （SAE：Eu2＋） was synthesized by a solid state reaction. In this study, XRD, PL/PLE, QE, thermal stability and LED package tests are systematically carried out and investigated. The optimized-composition of （Sro 92Eu0.08）4Al14025 exhibited a green emission peak at 497 nm under excitation wavelength of 400 nm, giving the chromaticity coordinates of （0.14, 0.35） with excellent quantum efficiency （98%） compared to those of other green-commodities, such as Ba2SiO4：Eu2＋ （90%） and BaMgAl10O17：EU2＋, Mn2＋ （92%）. The results demonstrated that SAE：Eu2＋ could be a potential candidate as the NUV-pumping phosphor for applications in light-emitting diodes （LEDs）.
基金supported by the grants from the Natural Science Foundation of Zhejiang Province (Y406309)Research Program from Science and Technology Bureau of Jinhua City (2008-1-151)
文摘Eu2＋ and （or） Eu3＋ doped Sr2SiO4 phosphors particles were synthesized by a conventional solid-state reaction technique, and their structural and optical properties were investigated. The X-ray diffraction （XRD） results showed that the obtained phosphors were composed of orthorhombic α′-Sr2SiO4 and monoclinic β-Sr2SiO4 phase. When excited under 256 nm, Sr2SiO4：Eu3＋ phosphors showed intense emission in the red region. Sr2SiO4：Eu3＋ phosphors exhibited white emissions （x=0.30, y=0.40, Tc=6500 K） ranging from 425 to 650 nm when it was excited by near-ultraviolet （near-UV） light, indicating that Sr2SiOn：Eu2＋ was a good light-conversion phosphor candidate for near-UV chip.
