The new Eu 3+ doped lanthanum oxysulfide phosphors,which have the orange-red long afterg low emission,were synthesized by solid-state reaction method.The synthesized phosphors were characterized by X-ray diffraction.T...The new Eu 3+ doped lanthanum oxysulfide phosphors,which have the orange-red long afterg low emission,were synthesized by solid-state reaction method.The synthesized phosphors were characterized by X-ray diffraction.The excitation and emission spectra,afterglow spectra and afterglow decay curves were examined.XRD confirm ed the phosphor as pure phase La 2 O 2 S.The phosphors showed typical transitions 5 D J (J=0,1) → 7 F J (J=0,1,2,3,4)of Eu 3+ .The photoluminescence spectra and afterglow spectra presented the regular alteration with various Eu 3+ concentration,due to cross relaxation between energy levels of Eu 3+ .In addition,we studied the effects of activator concentration and dopants species on the afterglow property.The data showed afterglow result was the bes t with2%Eu 3+ and doped with Mg 2+ and Zr 4+ .A prominent phosphorescence can be seen in this phosphor after illuminated with UV light.展开更多
The new Er3+, Ho3+ and Tm3+ doped gadolinium oxysulfide phosphors with the long afterglow emission were synthesized by solid-state reaction method. The synthesized phosphors were characterized by X-ray diffraction. Th...The new Er3+, Ho3+ and Tm3+ doped gadolinium oxysulfide phosphors with the long afterglow emission were synthesized by solid-state reaction method. The synthesized phosphors were characterized by X-ray diffraction. The excitation and photoluminescence spectra, afterglow spectra and afterglow decay curve were examined by fluorescence spectroscopy. The afterglow spectra of Gd2O2S∶Er3+, Mg, Ti showed typical transitions of Er3+ at 528 (2H11/2 → 4I15/2),548 (4S3/2 → 4I15/2) and 669 nm (4F9/2 → 4I15/2). In the afterglow spectra of Gd2O2S∶ Ho3+, Mg, Ti, typical transitions of Ho3+ at 546 nm (5S2 → 5I8), 651 and 661 nm (5F5 → 5I8) were observed. In Gd2O2S∶Tm3+, Mg, Ti, the afterglow emission at 800 nm (1G4 → 3H5) of Tm3+ was seen. The mechnism and model of afterglow energy transfer were proposed.展开更多
Nanoparticles of red long afterglow phosphor Sr3Al2O6: Eu2+ were prepared by microwave irradiation method at a power of 680 W and a processing time of 15 min. The phosphors nanoparticles were characterized by X-ray di...Nanoparticles of red long afterglow phosphor Sr3Al2O6: Eu2+ were prepared by microwave irradiation method at a power of 680 W and a processing time of 15 min. The phosphors nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fluorescence spectrophotometer techniques. The results reveal that the samples are composed of single Sr3Al2O6 phase. The resultant nanoparticles show small size (80?100 nm) and spherical shape. The excitation and emission spectra indicate that excitation broad band chiefly lies in visible range and the nanoparticles emit much strong light at 612 nm under around 473 nm excitation. And the long afterglow phosphorescence of Sr3Al2O6 doped with Eu2+ was observed in the dark with naked eye after the removal of the excitation light. The effect of Eu2+ doping concentrations of the samples on the emission intensity is studied systematically. Furthermore, the microwave method requires a very short heating-time and the energy consumption.展开更多
The Eu, Tb co-doped SiO2 matrix tricolor fluorescence system was prepared by sol-gel technique. Red emission at 618 nm, green emission at 543 nm and blue emission at 350―500 nm were observed in the PL spectra of the ...The Eu, Tb co-doped SiO2 matrix tricolor fluorescence system was prepared by sol-gel technique. Red emission at 618 nm, green emission at 543 nm and blue emission at 350―500 nm were observed in the PL spectra of the sample, indicating that Eu3+, Eu2+ and Tb3+ ions coexisted in the matrix. In the co-doped sample, the blue emission of Eu2+ was much stronger than that of the sample single doped with Eu, which implied that the electron transfer between Eu3+ and Tb3+ maybe happened in the SiO2 matrix. The influences of the annealing temperature and Tb concentration on the PL spectra of the samples were investigated. The optimal doped concentration of Tb was determined to be 0.2% and the optimal annealing temperature 850℃. Annealed at 600℃, Tb3+ had a sensitizing effect on Eu3+ in the SiO2 matrix, and the emission intensity of Eu3+ in the Eu, Tb co-doped sample was more than four times that of the single doped sample, which could be attributed to the energy transfer from Tb3+ to Eu3+.展开更多
In this paper,we report on long-persistence white phosphor SrAl2Si2O8:Eu2+,Dy3+ synthesized by the sol-gel method.The luminescent materials prepared by the sol-gel method have many advantages,such as uniform compositi...In this paper,we report on long-persistence white phosphor SrAl2Si2O8:Eu2+,Dy3+ synthesized by the sol-gel method.The luminescent materials prepared by the sol-gel method have many advantages,such as uniform composition,high purity,fine grains and low synthesis temperature.We found that SrAl2Si2O8:Eu2+,Dy3+ phosphor prepared by the sol-gel method can provide more luminescent intensity and better afterglow characteristic compared with the same phosphor prepared by solid-state method.Namely,the particle size and shape of phosphors should be optimized to obtain the maximum quantum efficiency through energy absorption.The microstructure of the phosphor consisted of regular fine grains with an average size of about 0.5-1 μm.Under 356 nm light excitation,the broadband emission of the phosphor continues from 350 to 650 nm and the emission peak is at about 414 nm,which can be viewed as the typical emission of Eu2+ ascribed to the 4f→5d transitions.展开更多
0521685多模网络方法分析电介质周期结构=Analysis of Di-electric Periodic Structures with Multi-Mode NetworkMethod[刊,英]/Zhanzhan Wu,Shanjia Xu//Interna-tional Journal of Infrared and Millimeter Waves.—2003,24(9).—150...0521685多模网络方法分析电介质周期结构=Analysis of Di-electric Periodic Structures with Multi-Mode NetworkMethod[刊,英]/Zhanzhan Wu,Shanjia Xu//Interna-tional Journal of Infrared and Millimeter Waves.—2003,24(9).—1509-1524(E)0521686采用组合化学的 Gd2O3∶Eu,锂磷光粉合成和其光致发光行为=Synthesis of Gd2O3∶Eu,Li Phosphor byModified Combinatorial Chemistry and Its Photolumines-cence Behavior[刊,英]/J.Kyu Park//Journal of TheElectrochemical Society.—2003,150(1).—27(E)展开更多
文摘The new Eu 3+ doped lanthanum oxysulfide phosphors,which have the orange-red long afterg low emission,were synthesized by solid-state reaction method.The synthesized phosphors were characterized by X-ray diffraction.The excitation and emission spectra,afterglow spectra and afterglow decay curves were examined.XRD confirm ed the phosphor as pure phase La 2 O 2 S.The phosphors showed typical transitions 5 D J (J=0,1) → 7 F J (J=0,1,2,3,4)of Eu 3+ .The photoluminescence spectra and afterglow spectra presented the regular alteration with various Eu 3+ concentration,due to cross relaxation between energy levels of Eu 3+ .In addition,we studied the effects of activator concentration and dopants species on the afterglow property.The data showed afterglow result was the bes t with2%Eu 3+ and doped with Mg 2+ and Zr 4+ .A prominent phosphorescence can be seen in this phosphor after illuminated with UV light.
文摘The new Er3+, Ho3+ and Tm3+ doped gadolinium oxysulfide phosphors with the long afterglow emission were synthesized by solid-state reaction method. The synthesized phosphors were characterized by X-ray diffraction. The excitation and photoluminescence spectra, afterglow spectra and afterglow decay curve were examined by fluorescence spectroscopy. The afterglow spectra of Gd2O2S∶Er3+, Mg, Ti showed typical transitions of Er3+ at 528 (2H11/2 → 4I15/2),548 (4S3/2 → 4I15/2) and 669 nm (4F9/2 → 4I15/2). In the afterglow spectra of Gd2O2S∶ Ho3+, Mg, Ti, typical transitions of Ho3+ at 546 nm (5S2 → 5I8), 651 and 661 nm (5F5 → 5I8) were observed. In Gd2O2S∶Tm3+, Mg, Ti, the afterglow emission at 800 nm (1G4 → 3H5) of Tm3+ was seen. The mechnism and model of afterglow energy transfer were proposed.
基金Project (50072014) supported by the National Natural Science Foundation of China
文摘Nanoparticles of red long afterglow phosphor Sr3Al2O6: Eu2+ were prepared by microwave irradiation method at a power of 680 W and a processing time of 15 min. The phosphors nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fluorescence spectrophotometer techniques. The results reveal that the samples are composed of single Sr3Al2O6 phase. The resultant nanoparticles show small size (80?100 nm) and spherical shape. The excitation and emission spectra indicate that excitation broad band chiefly lies in visible range and the nanoparticles emit much strong light at 612 nm under around 473 nm excitation. And the long afterglow phosphorescence of Sr3Al2O6 doped with Eu2+ was observed in the dark with naked eye after the removal of the excitation light. The effect of Eu2+ doping concentrations of the samples on the emission intensity is studied systematically. Furthermore, the microwave method requires a very short heating-time and the energy consumption.
基金Supported by the National Natural Science Foundation of Director (Grant No. 10247007)Natural Science Foundation of Shanxi Province (Grant No. 2003F22)the Science Technology Department of Shanxi Province (Grant No. 2004k05-G26)
文摘The Eu, Tb co-doped SiO2 matrix tricolor fluorescence system was prepared by sol-gel technique. Red emission at 618 nm, green emission at 543 nm and blue emission at 350―500 nm were observed in the PL spectra of the sample, indicating that Eu3+, Eu2+ and Tb3+ ions coexisted in the matrix. In the co-doped sample, the blue emission of Eu2+ was much stronger than that of the sample single doped with Eu, which implied that the electron transfer between Eu3+ and Tb3+ maybe happened in the SiO2 matrix. The influences of the annealing temperature and Tb concentration on the PL spectra of the samples were investigated. The optimal doped concentration of Tb was determined to be 0.2% and the optimal annealing temperature 850℃. Annealed at 600℃, Tb3+ had a sensitizing effect on Eu3+ in the SiO2 matrix, and the emission intensity of Eu3+ in the Eu, Tb co-doped sample was more than four times that of the single doped sample, which could be attributed to the energy transfer from Tb3+ to Eu3+.
文摘In this paper,we report on long-persistence white phosphor SrAl2Si2O8:Eu2+,Dy3+ synthesized by the sol-gel method.The luminescent materials prepared by the sol-gel method have many advantages,such as uniform composition,high purity,fine grains and low synthesis temperature.We found that SrAl2Si2O8:Eu2+,Dy3+ phosphor prepared by the sol-gel method can provide more luminescent intensity and better afterglow characteristic compared with the same phosphor prepared by solid-state method.Namely,the particle size and shape of phosphors should be optimized to obtain the maximum quantum efficiency through energy absorption.The microstructure of the phosphor consisted of regular fine grains with an average size of about 0.5-1 μm.Under 356 nm light excitation,the broadband emission of the phosphor continues from 350 to 650 nm and the emission peak is at about 414 nm,which can be viewed as the typical emission of Eu2+ ascribed to the 4f→5d transitions.
文摘0521685多模网络方法分析电介质周期结构=Analysis of Di-electric Periodic Structures with Multi-Mode NetworkMethod[刊,英]/Zhanzhan Wu,Shanjia Xu//Interna-tional Journal of Infrared and Millimeter Waves.—2003,24(9).—1509-1524(E)0521686采用组合化学的 Gd2O3∶Eu,锂磷光粉合成和其光致发光行为=Synthesis of Gd2O3∶Eu,Li Phosphor byModified Combinatorial Chemistry and Its Photolumines-cence Behavior[刊,英]/J.Kyu Park//Journal of TheElectrochemical Society.—2003,150(1).—27(E)
