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
Some new photostimulable F centers in the X-rayed BaFX: Eu2^+ were found. Their absorption bands are located in IR region. PSL process of X-rayed BaFX:Eu^(2+) consists of two subordinated process—e^--h^+ recombinatio...Some new photostimulable F centers in the X-rayed BaFX: Eu2^+ were found. Their absorption bands are located in IR region. PSL process of X-rayed BaFX:Eu^(2+) consists of two subordinated process—e^--h^+ recombination and radiative transition of Eu2^+ ions. The latter is a slow and rate-determining step. Dynamics and mechanism of that PSL have been investigated.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
An organic-inorganic composite dip-coating method was adopted in order to obtain ideal water repellent cotton fabrics. To be specific, a dual-functional coating with both superhydrophobic and luminescent properties wa...An organic-inorganic composite dip-coating method was adopted in order to obtain ideal water repellent cotton fabrics. To be specific, a dual-functional coating with both superhydrophobic and luminescent properties was prepared on cotton fabric by using a dip-coating solution comprising （3-aminopropyl） trimethoxysilane （APTMS） modified SrA1204：Eu2＋,Dy3＋particles, SU8, and fluorinated alkyl silane （FAS）. The micro/nano-scale roughness generated by SrA1204：Eu2＋,Dy3＋ particles, together with low-sur- face-energy FAS, rendered the cotton fabric superhydrophobic with a water contact angle of about 160° and a sliding angle as small as 2°. The coated fabric could withstand at least 100 cycles of standard laundry. The emission spectra of the coated fabric showed two emission peaks at 440 and 520 nm, which belonged to the blue and yellow-green color areas, respectively. The afterglow duration of the coated fabric was mainly influenced by the different depths of the trap levels in the SrA1204：Eu2＋,Dy3＋.展开更多
The present paper reported the structural and luminescent properties of Eu^（2＋） and Nd^（3＋） doped CaAl_2O_4 phosphor. The samples were prepared by microwave-assisted chemical co-precipitation（MA-CCP）, a synthe...The present paper reported the structural and luminescent properties of Eu^（2＋） and Nd^（3＋） doped CaAl_2O_4 phosphor. The samples were prepared by microwave-assisted chemical co-precipitation（MA-CCP）, a synthesis technique which is suitable for small and uniform particle that could be used directly without grinding. The effects of different microwave temperatures on structure and photoluminescence behavior were studied. Formation of a phosphor and phase purity were confirmed by X-ray diffraction technique（XRD） with variable microwave temperatures. XRD analysis showed that the phosphors prepared by MA-CCP method at the temperature of 750, 900oC, respectively and solid-state reaction（SSR） method at 1300oC consisted of impurities. Commission Internationale de L＇Eclairage（CIE） color coordinates of CaAl_2O_4：Eu^（2＋）,Nd^（3＋） were suitable as blue light emitting phosphor. Excitation and emission peaks of the samples prepared by different methods in this study were almost the same. The images of SEM showed that the size of the phosphors prepared by MA-CCP method reached a submicrometer.展开更多
A series of blue long afterglow mixed halide-phosphate phosphors Sr5 （PO4）3 FxCll-x：Eu2＋,Gd3＋ were synthesized in air by traditional solid-state reaction routte. The crystal structures, photoluminescence, thermol...A series of blue long afterglow mixed halide-phosphate phosphors Sr5 （PO4）3 FxCll-x：Eu2＋,Gd3＋ were synthesized in air by traditional solid-state reaction routte. The crystal structures, photoluminescence, thermolurninescenee properties and afterglow proper- ties of the phosphors were characterized systematically using X-ray diffraction （XRD）, luminescence spectrophotometer, microcom- puter thermoluminescence dosimeter and single photon counter, respectively. Under 280 nm excitation, the broadband emissions of Eu2＋ ions were observed at 445 nm （blue） due to the 4f7→4f65d transition. It was demonstrated that there existed the self-reduction of the Eu3＋ to Eu2＋ ions in this special halide-phosphate matrix in air condition. The addition of Gd3＋ ions obviously enhanced the after- glow properties of the single doped Eu2＋ ions in the halide-phosphate phosphors. And the content of the fluoride anions also had sig- nificant influence on the afterglow properties. All results indicated that Srs （PO4）3 FxCI1-x：Eu2＋,Gd3＋ might be potential phosphors for long lasting phosphorescence （LLP） materials.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.
基金The project supported by the Natioal Natural Science Foundation of China
文摘Some new photostimulable F centers in the X-rayed BaFX: Eu2^+ were found. Their absorption bands are located in IR region. PSL process of X-rayed BaFX:Eu^(2+) consists of two subordinated process—e^--h^+ recombination and radiative transition of Eu2^+ ions. The latter is a slow and rate-determining step. Dynamics and mechanism of that PSL have been investigated.
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Project supported by the Fundamental Research Funds for the Central Universities(Key Projects of Scientific Research Plan,No.JUSRP51505)
文摘An organic-inorganic composite dip-coating method was adopted in order to obtain ideal water repellent cotton fabrics. To be specific, a dual-functional coating with both superhydrophobic and luminescent properties was prepared on cotton fabric by using a dip-coating solution comprising （3-aminopropyl） trimethoxysilane （APTMS） modified SrA1204：Eu2＋,Dy3＋particles, SU8, and fluorinated alkyl silane （FAS）. The micro/nano-scale roughness generated by SrA1204：Eu2＋,Dy3＋ particles, together with low-sur- face-energy FAS, rendered the cotton fabric superhydrophobic with a water contact angle of about 160° and a sliding angle as small as 2°. The coated fabric could withstand at least 100 cycles of standard laundry. The emission spectra of the coated fabric showed two emission peaks at 440 and 520 nm, which belonged to the blue and yellow-green color areas, respectively. The afterglow duration of the coated fabric was mainly influenced by the different depths of the trap levels in the SrA1204：Eu2＋,Dy3＋.
基金Project supported by the Fundamental Research Funds for the Central Universities(JUSRP51723B)National Natural Science Foundation of China(51503083)+2 种基金Jiangsu Province Ordinary University Academic Degree Graduate Student Scientific Research Innovation Projects(KYLX16_0798)the Priority Academic Program Development of Jiangsu Higher Education InstitutionsProduction,Education&Research Cooperative Innovation Fund Project of Jiangsu Province(BY2015057-23)
文摘The present paper reported the structural and luminescent properties of Eu^（2＋） and Nd^（3＋） doped CaAl_2O_4 phosphor. The samples were prepared by microwave-assisted chemical co-precipitation（MA-CCP）, a synthesis technique which is suitable for small and uniform particle that could be used directly without grinding. The effects of different microwave temperatures on structure and photoluminescence behavior were studied. Formation of a phosphor and phase purity were confirmed by X-ray diffraction technique（XRD） with variable microwave temperatures. XRD analysis showed that the phosphors prepared by MA-CCP method at the temperature of 750, 900oC, respectively and solid-state reaction（SSR） method at 1300oC consisted of impurities. Commission Internationale de L＇Eclairage（CIE） color coordinates of CaAl_2O_4：Eu^（2＋）,Nd^（3＋） were suitable as blue light emitting phosphor. Excitation and emission peaks of the samples prepared by different methods in this study were almost the same. The images of SEM showed that the size of the phosphors prepared by MA-CCP method reached a submicrometer.
基金Project supported by Cooperation Project in Industry, Education and Research of Guangdong Province and Ministry of Education of China （2012B09110044）, and the Guangdong Provincial Natural Science Foundation of China （9151009001000052 ）
文摘A series of blue long afterglow mixed halide-phosphate phosphors Sr5 （PO4）3 FxCll-x：Eu2＋,Gd3＋ were synthesized in air by traditional solid-state reaction routte. The crystal structures, photoluminescence, thermolurninescenee properties and afterglow proper- ties of the phosphors were characterized systematically using X-ray diffraction （XRD）, luminescence spectrophotometer, microcom- puter thermoluminescence dosimeter and single photon counter, respectively. Under 280 nm excitation, the broadband emissions of Eu2＋ ions were observed at 445 nm （blue） due to the 4f7→4f65d transition. It was demonstrated that there existed the self-reduction of the Eu3＋ to Eu2＋ ions in this special halide-phosphate matrix in air condition. The addition of Gd3＋ ions obviously enhanced the after- glow properties of the single doped Eu2＋ ions in the halide-phosphate phosphors. And the content of the fluoride anions also had sig- nificant influence on the afterglow properties. All results indicated that Srs （PO4）3 FxCI1-x：Eu2＋,Gd3＋ might be potential phosphors for long lasting phosphorescence （LLP） materials.
