YAG：Ce3＋ phosphor was prepared by a novel co-precipitation-rheological phase method.The resulting YAG：Ce3＋ phosphor was characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM） and photolumine...YAG：Ce3＋ phosphor was prepared by a novel co-precipitation-rheological phase method.The resulting YAG：Ce3＋ phosphor was characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM） and photoluminescent emission spectra.By using acetic acid as solvent,YAG：Ce3＋ powder with small particle size（≤2 μm） was obtained at a relatively lower sintering temperature of 1400 oC.With the content of acetic acid increasing,small particles dissolved and disappeared,but larger particles grew up and changed its shape from spherical to partially rectangular.Meanwhile,the emission intensity of the sample prepared by co-precipitation-rheological phase method was about 43% higher than that of the sample prepared by co-precipitation method.It was assumed that the significant improvement of luminescence was mainly because the rheological phase presented a better diffusion environment,and therefore,a better homogeneity of activators of Ce3＋.展开更多
The sulfate ions modified YAG：Ce^（3＋） phosphors were prepared by co-precipitation method and characterized by X-ray diffraction,transmission electron microscopy,and photoluminescence.Effects of sulfate ions on the...The sulfate ions modified YAG：Ce^（3＋） phosphors were prepared by co-precipitation method and characterized by X-ray diffraction,transmission electron microscopy,and photoluminescence.Effects of sulfate ions on the photoluminescence（PL） property of the as-prepared YAG：Ce^（3＋） phosphors were studied,with sodium dodecyl sulfate（SDS） being added to R^（3＋）（Ce^（3＋）,Y^（3＋）,Al^（3＋）） ions.Results indicated that pure YAG：Ce^（3＋） phosphors with different ratios of sulfate ions could be easily obtained by calcining the as-synthesized precursor at 950 ℃ for 2 h,the YAG：Ce^（3＋） phosphors with an optimal mass ratio of 3.5 wt.%SDS had the highest emission intensity and the best dispersion behavior,and the fluorescence decay of the as-obtained YAG：Ce^（3＋） phosphors was related to the lattice defect,reabsorption and cross correlation.Furthermore,thermal quenching properties of the YAG：Ce^（3＋） phosphors and the YAG：Ce^（3＋） phosphors with 3.5 wt.%SDS were also discussed,indicating that the YAG：Ce^（3＋） with SDS phosphors could have potential applications in the daylight LEDs or warm white LEDs.展开更多
采用高温固相法反应制备Ba0.11Sr2.89-2x Ce x Na x AlO4F(x=0.01,0.02,0.05,0.07,0.10,0.15)荧光粉。Ba0.11Sr2.89AlO4F体系中存在Sr(1)2+和Sr2+(2)两个格位。Sr2+(1)离子位于Wyck.4a格位,为十配位多面体构型。Sr2+(2)离子位于Wyck.8h...采用高温固相法反应制备Ba0.11Sr2.89-2x Ce x Na x AlO4F(x=0.01,0.02,0.05,0.07,0.10,0.15)荧光粉。Ba0.11Sr2.89AlO4F体系中存在Sr(1)2+和Sr2+(2)两个格位。Sr2+(1)离子位于Wyck.4a格位,为十配位多面体构型。Sr2+(2)离子位于Wyck.8h格位,为八配位的多面体构型。研究了Ba0.11Sr2.89-2x Ce x Na x AlO4F荧光粉的紫外-可见激发、发射光谱、荧光寿命及能量传递过程,讨论并指认了Ce3+在上述两个格位中的激发带位置及能级重心,发射光谱曲线分别由两个~463,~505和~550 nm宽带发射构成。随着Ce3+浓度增加,长波发射~550 nm逐渐增强,而色品坐标(x=0.199,y=0.351)蓝绿区逐渐变化到黄绿区域(x=0.389,y=0.489)。展开更多
The Y3(AI,Ga)5O12:Ce^3+,Cr^3+,Nd^3+(YAGG)nano-phosphors with homogeneous particle-size distribution,low aggregation and average crystalline size of about 65 nm were obtained using a modified Pechini method.Only slight...The Y3(AI,Ga)5O12:Ce^3+,Cr^3+,Nd^3+(YAGG)nano-phosphors with homogeneous particle-size distribution,low aggregation and average crystalline size of about 65 nm were obtained using a modified Pechini method.Only slight aggregation of the crystallites occurs after post-annealing at 1100℃.The intense Ce^3+bands in the excitation spectra of the Ce^3+,Cr^3+,Nd^3+co-doped materials monitoring the Cr^3+emission at 690 nm indicate energy transfer from Ce^3+to Cr^3+.Weak Nd^3+lines are observed,as well.In addition,the emission of Nd^3+at 1060 nm with excitation of Ce^3+and Cr^3+confirms the Ce^3+/Cr^3+to Nd^3+energy transfer.The short average luminescence decay times for the Ce^3+emission indicate the Ce^3+/Cr^3+to Nd^3+energy transfer.Eventually,the Y3(AI,Ga)5O12:Ce^3+,Cr^3+,Nd^3+nano-phosphors exhibit persistent luminescence originating from the 4f^3→4f^3 transitions of Nd^3+which matches well to the first biological window to be used in bioimaging applications.展开更多
BaAl12O19:Tb,Ce phosphors were prepared by sol-gel technique,the crystalline structures of samples characterized by XRD,and the luminescence properties and energy transfer between Ce3+ and Tb3+ were investigated.The r...BaAl12O19:Tb,Ce phosphors were prepared by sol-gel technique,the crystalline structures of samples characterized by XRD,and the luminescence properties and energy transfer between Ce3+ and Tb3+ were investigated.The results indicated that the emission intensity and the excitation wavelength range of Tb3+ increased when Ce3+ was doped.It demonstrated that the Ce3+ added in the BaAl12O19:Tb could deliver energy to Tb3+,and Ce3+ was not luminous by itself.The relative emission intensity of Tb3+ at wavelength of 548 nm was the strongest by Tb3+/Ce3+ ratio of 2:1,when excited at 310 nm,which was the characteristic adsorption wavelength of Ce3+.展开更多
Praseodymium（III） doped CeF3, CeF3：Gd, LaF3, GdF3 and YF3 inorganic fluorides were precipitated in an aqueous, sur- factant-free solution, using NH4F as a source of fluoride ions. The as-prepared products were subj...Praseodymium（III） doped CeF3, CeF3：Gd, LaF3, GdF3 and YF3 inorganic fluorides were precipitated in an aqueous, sur- factant-free solution, using NH4F as a source of fluoride ions. The as-prepared products were subjected to a hydrothermal treatment, which led to the formation of crystalline nanoluminophores, composed of spherical （30 nm） and elongated （40-200 nm） nanos- tructures. Due to the presence of Pr3＋ ions, the synthesized nanomaterials showed yellow luminescence under a blue light irradiation. The nanoluminophore based on the YF3 host revealed the most promising spectroscopic properties, i.e., bright and intensive emission, hence it was investigated in detail. The photophysical properties of the nanomaterials obtained were studied by powder X-ray diffrac- tion （XRD）, transmission electron microscopy （TEM） and spectrofluorometry, i.e., measurements of excitation/emission spectra and luminescence decay curves.展开更多
基金Project supported by the Natural Science Foundation of Jiangxi Province (2009GQC0042)Foundation of Jiangxi Educational Committee(GJJ10153)+1 种基金Major Science and Technology Project of Jiangxi Province (2010AZD00100)Foundation of Jiangxi University of Science and Technology (Jxxjzd10007)
文摘YAG：Ce3＋ phosphor was prepared by a novel co-precipitation-rheological phase method.The resulting YAG：Ce3＋ phosphor was characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM） and photoluminescent emission spectra.By using acetic acid as solvent,YAG：Ce3＋ powder with small particle size（≤2 μm） was obtained at a relatively lower sintering temperature of 1400 oC.With the content of acetic acid increasing,small particles dissolved and disappeared,but larger particles grew up and changed its shape from spherical to partially rectangular.Meanwhile,the emission intensity of the sample prepared by co-precipitation-rheological phase method was about 43% higher than that of the sample prepared by co-precipitation method.It was assumed that the significant improvement of luminescence was mainly because the rheological phase presented a better diffusion environment,and therefore,a better homogeneity of activators of Ce3＋.
基金supported by the Research Fund for Doctoral Program of Higher Education of China(20120201130004)the Science and Technology Developing Project of Shaanxi Province(2015KW-001)+1 种基金the National Natural Science Foundation of China(61078058)Partially by the National Natural Science Foundation of China Major Research Plan on Nanomanufacturing(91323303)
文摘The sulfate ions modified YAG：Ce^（3＋） phosphors were prepared by co-precipitation method and characterized by X-ray diffraction,transmission electron microscopy,and photoluminescence.Effects of sulfate ions on the photoluminescence（PL） property of the as-prepared YAG：Ce^（3＋） phosphors were studied,with sodium dodecyl sulfate（SDS） being added to R^（3＋）（Ce^（3＋）,Y^（3＋）,Al^（3＋）） ions.Results indicated that pure YAG：Ce^（3＋） phosphors with different ratios of sulfate ions could be easily obtained by calcining the as-synthesized precursor at 950 ℃ for 2 h,the YAG：Ce^（3＋） phosphors with an optimal mass ratio of 3.5 wt.%SDS had the highest emission intensity and the best dispersion behavior,and the fluorescence decay of the as-obtained YAG：Ce^（3＋） phosphors was related to the lattice defect,reabsorption and cross correlation.Furthermore,thermal quenching properties of the YAG：Ce^（3＋） phosphors and the YAG：Ce^（3＋） phosphors with 3.5 wt.%SDS were also discussed,indicating that the YAG：Ce^（3＋） with SDS phosphors could have potential applications in the daylight LEDs or warm white LEDs.
文摘采用高温固相法反应制备Ba0.11Sr2.89-2x Ce x Na x AlO4F(x=0.01,0.02,0.05,0.07,0.10,0.15)荧光粉。Ba0.11Sr2.89AlO4F体系中存在Sr(1)2+和Sr2+(2)两个格位。Sr2+(1)离子位于Wyck.4a格位,为十配位多面体构型。Sr2+(2)离子位于Wyck.8h格位,为八配位的多面体构型。研究了Ba0.11Sr2.89-2x Ce x Na x AlO4F荧光粉的紫外-可见激发、发射光谱、荧光寿命及能量传递过程,讨论并指认了Ce3+在上述两个格位中的激发带位置及能级重心,发射光谱曲线分别由两个~463,~505和~550 nm宽带发射构成。随着Ce3+浓度增加,长波发射~550 nm逐渐增强,而色品坐标(x=0.199,y=0.351)蓝绿区逐渐变化到黄绿区域(x=0.389,y=0.489)。
基金Project supported by Polish National Science Centre(Project:OPUS11#2016/21/B/ST5/02385)
文摘The Y3(AI,Ga)5O12:Ce^3+,Cr^3+,Nd^3+(YAGG)nano-phosphors with homogeneous particle-size distribution,low aggregation and average crystalline size of about 65 nm were obtained using a modified Pechini method.Only slight aggregation of the crystallites occurs after post-annealing at 1100℃.The intense Ce^3+bands in the excitation spectra of the Ce^3+,Cr^3+,Nd^3+co-doped materials monitoring the Cr^3+emission at 690 nm indicate energy transfer from Ce^3+to Cr^3+.Weak Nd^3+lines are observed,as well.In addition,the emission of Nd^3+at 1060 nm with excitation of Ce^3+and Cr^3+confirms the Ce^3+/Cr^3+to Nd^3+energy transfer.The short average luminescence decay times for the Ce^3+emission indicate the Ce^3+/Cr^3+to Nd^3+energy transfer.Eventually,the Y3(AI,Ga)5O12:Ce^3+,Cr^3+,Nd^3+nano-phosphors exhibit persistent luminescence originating from the 4f^3→4f^3 transitions of Nd^3+which matches well to the first biological window to be used in bioimaging applications.
基金Project supported by the Science and Technology Plan of Liaoning Province (2006223004)the Doctor Foundation of Liaoning Province (20101083)the Key Laboratory Project of the Education Department of Liaoning Province in China (2009S081)
文摘BaAl12O19:Tb,Ce phosphors were prepared by sol-gel technique,the crystalline structures of samples characterized by XRD,and the luminescence properties and energy transfer between Ce3+ and Tb3+ were investigated.The results indicated that the emission intensity and the excitation wavelength range of Tb3+ increased when Ce3+ was doped.It demonstrated that the Ce3+ added in the BaAl12O19:Tb could deliver energy to Tb3+,and Ce3+ was not luminous by itself.The relative emission intensity of Tb3+ at wavelength of 548 nm was the strongest by Tb3+/Ce3+ ratio of 2:1,when excited at 310 nm,which was the characteristic adsorption wavelength of Ce3+.
基金Project supported by the Polish National Science Centre(2015/17/N/ST5/01947)
文摘Praseodymium（III） doped CeF3, CeF3：Gd, LaF3, GdF3 and YF3 inorganic fluorides were precipitated in an aqueous, sur- factant-free solution, using NH4F as a source of fluoride ions. The as-prepared products were subjected to a hydrothermal treatment, which led to the formation of crystalline nanoluminophores, composed of spherical （30 nm） and elongated （40-200 nm） nanos- tructures. Due to the presence of Pr3＋ ions, the synthesized nanomaterials showed yellow luminescence under a blue light irradiation. The nanoluminophore based on the YF3 host revealed the most promising spectroscopic properties, i.e., bright and intensive emission, hence it was investigated in detail. The photophysical properties of the nanomaterials obtained were studied by powder X-ray diffrac- tion （XRD）, transmission electron microscopy （TEM） and spectrofluorometry, i.e., measurements of excitation/emission spectra and luminescence decay curves.
