Ce3＋, Yb3＋ co-doped Y3Al5O12 films were prepared by pulse laser deposition. X-ray diffraction, X-ray photoelectron spectroscopy, photoluminescence spectra were used to characterize their structural and luminescent p...Ce3＋, Yb3＋ co-doped Y3Al5O12 films were prepared by pulse laser deposition. X-ray diffraction, X-ray photoelectron spectroscopy, photoluminescence spectra were used to characterize their structural and luminescent properties. Near-infrared quantum cutting from the films was observed via a cooperative energy transfer from Ce3＋ to Yb3＋ ions. The high quantum efficiency of the films implies that Ce3＋,Yb3＋ co-doped Y3A15O12 films have potential application by tuning the solar spectrum to enhance the efficiency of silicon solar cells.展开更多
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
Abstract： Monophasic Ce3＋ and Pr3＋ co-doped yttrium aluminum garnet （YAG：Ce3＋,pr3＋） nanoparticles with good dispersity and uniform grain sizes in the range of 50-80 nm were prepared by a two-step route, which ...Abstract： Monophasic Ce3＋ and Pr3＋ co-doped yttrium aluminum garnet （YAG：Ce3＋,pr3＋） nanoparticles with good dispersity and uniform grain sizes in the range of 50-80 nm were prepared by a two-step route, which consisted of a modified co-precipitation preparation of mixed metal hydroxide hydrate intermediates at low temperature of about 40℃ and a subsequent calcination conversion of the synthesized intermediates to crystalline nanoparticle products at about 1000℃. The influences of both the lanthanide ion （Ce3＋ and Pr3＋） doping concentration and different doping （Ce3＋/pr3＋） ratio on the photoluminescence intensity were systematically investigated. The synthesized （Ce0.6Pr0.4）0.04Y2.96Al5O12 nanoparticles were near spherical nanoclusters with good dispersity and uniform sizes in the range of 50-80 nm for about 85% of the particles. The strongest photoluminescence intensity was observed for the （Ce0.6Pr0.4）0.04Y2.96Al5O12 nanoparticle products.展开更多
YAG：Ce,Sm spherical phosphors were synthesized by malic acid sol-gel method. The formation process of crystalline was characterized by X-ray diffraction （XRD） technique. The influence of Sm3＋ doping on the lumines...YAG：Ce,Sm spherical phosphors were synthesized by malic acid sol-gel method. The formation process of crystalline was characterized by X-ray diffraction （XRD） technique. The influence of Sm3＋ doping on the luminescent intensity and the morphology of phosphors were studied by fluorescence spectrum and scanning electron microscopy （SEM） techniques, respectively. The results indicated that the size of spherical powders was about 100 um calcined at 1200 ℃ for 3 h. The emission spectra of phosphors showed gradual red-shift from 525 to 540 um with the increase of doping concentration of Sm3＋ ion. A broadband emission specmtm of Ce3＋ ion appeared at 540 nm, and a series of emission peaks corresponding to the 4Gs/2-＋6Hd transition of Sm3＋ ion also appeared at 617 um with the doping of Sm3＋. The red component of YAG：Ce phosphors increased with the doping of Sm3＋.展开更多
A Matlab （2009a） program was developed to simulate the photons emitted by the LED chips. The photons＇ transmission, reflection, and refraction in phosphor layers with different shapes were calculated in this progra...A Matlab （2009a） program was developed to simulate the photons emitted by the LED chips. The photons＇ transmission, reflection, and refraction in phosphor layers with different shapes were calculated in this program. The CCT was calculated at different emergent angles with different layer profiles, such as planar layer, hemispherical layer （with different diameters）, half ellipsoid layer and other irregular shapes. As a consequence of optimization of angular color uniformity, the trend of configuration of the phosphor layer was discussed and analyzed.展开更多
基金Funded by the China Postdoctoral Science Foundation(No.2012M511801)the National Natural Science Foundation of China(Nos.11474104 and 51372092)
文摘Ce3＋, Yb3＋ co-doped Y3Al5O12 films were prepared by pulse laser deposition. X-ray diffraction, X-ray photoelectron spectroscopy, photoluminescence spectra were used to characterize their structural and luminescent properties. Near-infrared quantum cutting from the films was observed via a cooperative energy transfer from Ce3＋ to Yb3＋ ions. The high quantum efficiency of the films implies that Ce3＋,Yb3＋ co-doped Y3A15O12 films have potential application by tuning the solar spectrum to enhance the efficiency of silicon solar cells.
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Project supported by the National High Technology Research and Development Program of China(863 Program)(2013AA031901)the National Natural Science Foundation of China(51425202)+1 种基金the Natural Science Foundation of Jiangsu Province(BK20160093)Topnotch Academic Programs Project of Jiangsu Higher Education Institutions(TAPP)
文摘Abstract： Monophasic Ce3＋ and Pr3＋ co-doped yttrium aluminum garnet （YAG：Ce3＋,pr3＋） nanoparticles with good dispersity and uniform grain sizes in the range of 50-80 nm were prepared by a two-step route, which consisted of a modified co-precipitation preparation of mixed metal hydroxide hydrate intermediates at low temperature of about 40℃ and a subsequent calcination conversion of the synthesized intermediates to crystalline nanoparticle products at about 1000℃. The influences of both the lanthanide ion （Ce3＋ and Pr3＋） doping concentration and different doping （Ce3＋/pr3＋） ratio on the photoluminescence intensity were systematically investigated. The synthesized （Ce0.6Pr0.4）0.04Y2.96Al5O12 nanoparticles were near spherical nanoclusters with good dispersity and uniform sizes in the range of 50-80 nm for about 85% of the particles. The strongest photoluminescence intensity was observed for the （Ce0.6Pr0.4）0.04Y2.96Al5O12 nanoparticle products.
基金Project supported by the Scientific and Technological Department of Jilin Province (20120117)the Scientific and Technological Bureau of Changchun City (11KZ42)the project of Jilin development and Reform Commission (2011FGW03)
文摘YAG：Ce,Sm spherical phosphors were synthesized by malic acid sol-gel method. The formation process of crystalline was characterized by X-ray diffraction （XRD） technique. The influence of Sm3＋ doping on the luminescent intensity and the morphology of phosphors were studied by fluorescence spectrum and scanning electron microscopy （SEM） techniques, respectively. The results indicated that the size of spherical powders was about 100 um calcined at 1200 ℃ for 3 h. The emission spectra of phosphors showed gradual red-shift from 525 to 540 um with the increase of doping concentration of Sm3＋ ion. A broadband emission specmtm of Ce3＋ ion appeared at 540 nm, and a series of emission peaks corresponding to the 4Gs/2-＋6Hd transition of Sm3＋ ion also appeared at 617 um with the doping of Sm3＋. The red component of YAG：Ce phosphors increased with the doping of Sm3＋.
文摘A Matlab （2009a） program was developed to simulate the photons emitted by the LED chips. The photons＇ transmission, reflection, and refraction in phosphor layers with different shapes were calculated in this program. The CCT was calculated at different emergent angles with different layer profiles, such as planar layer, hemispherical layer （with different diameters）, half ellipsoid layer and other irregular shapes. As a consequence of optimization of angular color uniformity, the trend of configuration of the phosphor layer was discussed and analyzed.
