用高温固相法制备了YAG:5%Dy^3+以及(Ce 0.01 Dy y Y 0.99-y)3A15O12(y=0%,1%,3%,5%,7%,9%)荧光粉。XRD结果表明,NH 4Cl、LiCl、H3BO3三种助熔剂比较,添加H3BO3可有效降低YAG晶体的结晶温度,有效阻止中间相YAlO 3的形成。H3BO3做助熔剂...用高温固相法制备了YAG:5%Dy^3+以及(Ce 0.01 Dy y Y 0.99-y)3A15O12(y=0%,1%,3%,5%,7%,9%)荧光粉。XRD结果表明,NH 4Cl、LiCl、H3BO3三种助熔剂比较,添加H3BO3可有效降低YAG晶体的结晶温度,有效阻止中间相YAlO 3的形成。H3BO3做助熔剂在1450℃煅烧6 h制备的Dy^3+和Ce^3+掺杂Y 3Al 5O 12荧光粉具有单一YAG立方相结构,且随Dy^3+掺杂浓度增加,(420)衍射峰逐渐向小角度偏移。在583 nm监测下;与单掺1%Ce^3+样品比较,Ce^3+与Dy^3+共掺样品在342 nm处的吸收均减弱;与单掺5%Dy^3+样品比较,Ce^3+与Dy^3+共掺样品在351 nm处的吸收明显增强。351 nm激发下,随Dy^3+掺杂浓度增加,Ce^3+与Dy^3+共掺样品中Ce^3+在526 nm处的发射强度逐渐减小,而在583 nm处的发射强度先增加后减弱,这说明351 nm激发下,Ce^3+与Dy^3+共掺样品中存在Ce^3+向Dy^3+的部分能量传递。465 nm激发下,Ce^3+与Dy^3+共掺杂样品中只出现Ce^3+的发射峰,且随Dy^3+浓度增加,Ce^3+发光减弱。当Dy^3+离子浓度为3%时,Ce^3+与Dy^3+共掺样品中Dy^3+相对光强达到最大,此时Ce^3+→Dy^3+能量传递效率为15.7%。405 nm激发下,随Dy^3+掺杂浓度增加,合成粉体中Ce^3+的寿命逐渐减小。经计算,Ce^3+→Dy^3+能量传递临界距离为3.464 nm,为电四极-电四极相互作用的共振能量传递。展开更多
In the present paper, the concentration effect of near-infrared quantum cutting of Tm3＋ ion in （Y1-xTmx）3Al5Ol2 powder phosphor is studied by means of experiments and calculations. In addition, the absorption spect...In the present paper, the concentration effect of near-infrared quantum cutting of Tm3＋ ion in （Y1-xTmx）3Al5Ol2 powder phosphor is studied by means of experiments and calculations. In addition, the absorption spectra, visible-to-near- infrared excitation and emission spectra, and fluorescence lifetimes are measured. It is found that （Y1-xTmx）3Al5O12 powder phosphor has a strong four-photon near-infrared quantum cutting luminescence of 1788.0-nm 3F4 →3H6 fluores- cence of Tm3＋ ion, when excited by 357.0-nm light. It is also found that the up-limit of the four-photon near-infrared quantum cutting luminescence efficiency of （Yo.700Tmo.300）3Al5 O12 powder phosphor is approximately 302.19%. To the knowledge of the authors, this is the first time that a near-infrared quantum cutting efficiency up-limit exceeding 300% has been reported. The results of this manuscript are valuable in aiding the probing of the new generation Ge solar cell.展开更多
Lu3Al5O12 single crystals grown in pure N2 atmosphere by Czochralski method were annealed in oxidizing atmosphere （air）and reducing atmosphere （H2 ＋ N2）, respectively. Effects of annealing treatments on luminesce...Lu3Al5O12 single crystals grown in pure N2 atmosphere by Czochralski method were annealed in oxidizing atmosphere （air）and reducing atmosphere （H2 ＋ N2）, respectively. Effects of annealing treatments on luminescence and scintillation properties of the crystals were investigated. The crystal annealed in air showed the highest luminescence intensity under blue light or vacuum ultraviolet excitation in comparison with that annealed in reducing flux or the as-grown crystal. Under X-ray excitation, crystal annealed in reducing atmosphere had the lowest light yield, and crystal annealed in air had the fastest decay time under ^137Cs 662 keV γ-ray excitation. Different annealing treatments resulted in different luminescence and scintillation properties, which might related with oxygen vacancies or defect existing in the crystals.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.10674019)the Significant Project of Fundamental Research Funds for the Central Universities of China(Grant No.212-105560GK)
文摘In the present paper, the concentration effect of near-infrared quantum cutting of Tm3＋ ion in （Y1-xTmx）3Al5Ol2 powder phosphor is studied by means of experiments and calculations. In addition, the absorption spectra, visible-to-near- infrared excitation and emission spectra, and fluorescence lifetimes are measured. It is found that （Y1-xTmx）3Al5O12 powder phosphor has a strong four-photon near-infrared quantum cutting luminescence of 1788.0-nm 3F4 →3H6 fluores- cence of Tm3＋ ion, when excited by 357.0-nm light. It is also found that the up-limit of the four-photon near-infrared quantum cutting luminescence efficiency of （Yo.700Tmo.300）3Al5 O12 powder phosphor is approximately 302.19%. To the knowledge of the authors, this is the first time that a near-infrared quantum cutting efficiency up-limit exceeding 300% has been reported. The results of this manuscript are valuable in aiding the probing of the new generation Ge solar cell.
基金Project supported by the National Natural Science Foundation of China (20571088)the Science and Technology Project of Guangdong Province (2005B10301016, 2006B14801001)
文摘Lu3Al5O12 single crystals grown in pure N2 atmosphere by Czochralski method were annealed in oxidizing atmosphere （air）and reducing atmosphere （H2 ＋ N2）, respectively. Effects of annealing treatments on luminescence and scintillation properties of the crystals were investigated. The crystal annealed in air showed the highest luminescence intensity under blue light or vacuum ultraviolet excitation in comparison with that annealed in reducing flux or the as-grown crystal. Under X-ray excitation, crystal annealed in reducing atmosphere had the lowest light yield, and crystal annealed in air had the fastest decay time under ^137Cs 662 keV γ-ray excitation. Different annealing treatments resulted in different luminescence and scintillation properties, which might related with oxygen vacancies or defect existing in the crystals.
