Eu3+ activated CaWO4 was prepared by high temperature solid state reaction technique. Red afterglow was observed for in the CaWO4∶Eu after exciting with 254 nm light due to Eu3+ transition from 5D0 to 7FJ (J=0, 1, 2,...Eu3+ activated CaWO4 was prepared by high temperature solid state reaction technique. Red afterglow was observed for in the CaWO4∶Eu after exciting with 254 nm light due to Eu3+ transition from 5D0 to 7FJ (J=0, 1, 2, 3,4). By the cal culation of the thermoluminescence spectrum of CaWO4∶Eu, we conclude that there were two types of trap centers: VCa″ was formed by substitution of Ca2+ by Eu3 + and complex traps were produced because of substitution of W6+ by Eu3+.展开更多
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
Nano-sphere-like Eu3+ activated lanthanum oxysulfide phosphor was first synthesized directly by solvothermal method. The phosphor was characterized by XRD, TEM and PL. Photoluminescence spectra indicate that this phos...Nano-sphere-like Eu3+ activated lanthanum oxysulfide phosphor was first synthesized directly by solvothermal method. The phosphor was characterized by XRD, TEM and PL. Photoluminescence spectra indicate that this phosphor showed three typical transitions of Eu3+（（）5D0→（）7F1, （）5D0→（）7F2, （（）5D0→（）7F4）.） In comparison with those prepared by high temperature solid state method, photoluminescence spectrum of Eu3+（（）5D0→（）7F2）-doped nano-La2O2S∶Eu3+ phosphor became broader. And the reaction mechanism was also mentioned in this paper.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
文摘Eu3+ activated CaWO4 was prepared by high temperature solid state reaction technique. Red afterglow was observed for in the CaWO4∶Eu after exciting with 254 nm light due to Eu3+ transition from 5D0 to 7FJ (J=0, 1, 2, 3,4). By the cal culation of the thermoluminescence spectrum of CaWO4∶Eu, we conclude that there were two types of trap centers: VCa″ was formed by substitution of Ca2+ by Eu3 + and complex traps were produced because of substitution of W6+ by Eu3+.
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Nano-sphere-like Eu3+ activated lanthanum oxysulfide phosphor was first synthesized directly by solvothermal method. The phosphor was characterized by XRD, TEM and PL. Photoluminescence spectra indicate that this phosphor showed three typical transitions of Eu3+（（）5D0→（）7F1, （）5D0→（）7F2, （（）5D0→（）7F4）.） In comparison with those prepared by high temperature solid state method, photoluminescence spectrum of Eu3+（（）5D0→（）7F2）-doped nano-La2O2S∶Eu3+ phosphor became broader. And the reaction mechanism was also mentioned in this paper.
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.
