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1.
Ce3+, Tb3+ codoped amorphous calcium silicate phosphor was prepared by heating (830 °C for 30 min) Ce3+, Tb3+ codoped calcium silicate hydrate phosphor formed by liquid-phase reaction. The excitation peak wavelength of the resulting phosphor was 330 nm and the emission peak wavelengths were at 544 nm, attributed to the 5D4→7F5 transition of Tb3+, and at 430–470 mm, attributed to Ce3+. The intensity ratio of the two peaks could be freely controlled by varying the Tb/Ca atomic ratio of the Ce3+, Tb3+ codoped amorphous calcium silicate phosphor, allowing light to be emitted over a wide range from blue to green. It was clarified that energy transfer exists from Ce3+ to Tb3+. 相似文献
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The Y0.95?xAlxVO4:5%Eu3+ (0≤x≤0.1) phosphors were successfully synthesized by solid state reaction at 900 °C for 6 h, and their luminescence properties were investigated under UV and VUV excitation. Monitoring at 619 nm, a strong broad absorption was enhanced by co-doping of Al3+ into the YVO4:Eu3+ lattices at 256 nm under UV excitation. The VUV excitation spectra also showed the enhanced excitation bands at about 156 and 200 nm. Under 254 or 147 nm excitation, it was found that Y0.95?xAlxVO4:Eu3+(0≤x≤0.1) phosphors showed strong red emission at about 619 nm corresponding to the electric dipole 5D0–7F2 transition of Eu3+. The improvement of luminescence intensity of YVO4:Eu3+ was also observed after partial substituting Y3+ by Al3+ and the optimal luminescence intensity appeared with incorporation of 2.5 mol% Al3+. 相似文献
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Jiayue Sun Jicheng Zhu Xiangyan Zhang Zhiguo Xia Haiyan Du 《Journal of luminescence》2012,132(11):2937-2942
Novel blue/green NaSrPO4 phosphors co-doped with Eu2+ and Tb3+ were synthesized by a conventional solid-state reaction. Their luminescent properties were characterized by using powder X-ray diffraction, photoluminescence excitation and emission spectra, lifetime, and temperature dependent emission spectra, respectively. The NaSrPO4:Eu2+,Tb3+,Na+ phosphor showed an intense broad excitation band between 250 and 430 nm, which was in agreement with the near-UV chip (350–420 nm), and it exhibited two dominating emission bands at 445 and 545 nm, corresponding to the allowed 4f65d1→4f7(8S7/2) transition of Eu2+ ion and the 5D4→7F5 transition of Tb3+ ion, respectively. The emission intensity and lifetime of Eu2+ ion decreased with the increasing concentration of Tb3+ ion, which strongly indicated that an effective energy transfer occurred from Eu2+ to Tb3+ in NaSrPO4 host. The principle of the energy transfer should be the combined effect of the non-radiative resonant energy transfer and the phonon-assisted non-radiative process. 相似文献
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Z. Zhang J. Wang M. Zhang Q. Zhang Q. Su 《Applied physics. B, Lasers and optics》2008,91(3-4):529-537
Energy transfer from Eu2+ to Tb3+ was observed by investigating the optical properties from photoluminescence spectra and decay time curves in Tb3+ singly doped and Eu2+–Tb3+ co-doped calcium chlorapatite, Ca5(PO4)3Cl (CPCl). It is dominated by the cooperation of a phonon-assisted energy transfer process and a non-radiative resonant energy transfer process caused by the exchange interaction. Eu2+–Tb3+ co-doped calcium chlorapatite phosphors in which Tb3+ can be efficiently excited by 400 nm are potential candidates for phosphor-converted LED. 相似文献
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B.N. Mahalley S.J. Dhoble R.B. Pode G. Alexander 《Applied Physics A: Materials Science & Processing》2000,70(1):39-45
The doubly doped (Bi3+ and Eu3+) GdVO4 powder is synthesized by hydrolyzed colloid reaction (HCR) technique and formation of material is confirmed by XRD measurement. Surface morphology has been studied by SEM measurement and the result shows uniform surface morphology. The average particle size observed by SEM is about 1 7m. The Fritsch particle sizer is used to study the particle size distribution. It distributes from O.15 to 3.57 7m. The small particle size (less than 5 7m) and the narrow particle size distribution, are the necessary requirements of good phosphor material. Photoluminescence result shows a narrow emission line of Eu3+ ion (4 nm FWHM) at 618 nm. The Eu3+ emission intensity is enhanced by a factor of five with the addition of small amount of Bi3+. The emission bands of VO43- and Bi3+ partially overlap with the excitation band of Eu3+. The process of energy transfer from Bi3+ to Eu3+ is discussed here. The energy transfer probability is strongly dependent upon the Bi3+ and Eu3+ concentrations, with a maximum for 0.2 mol % of Bi3+ and 3 mol % of Eu3+. It drastically decreases for higher concentrations. For photoluminescent applications, the quantum efficiency (QE) of a phosphor material is an important parameter. The QE of GdVO4:Bi,Eu(0.2,3) is 76%. The GdVO4:Bi,Eu(0.2,3) material is proposed as an efficient photoluminescent phosphor. 相似文献
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Qiuhong Zhang Haiyong Ni Lingli Wang 《Applied Physics A: Materials Science & Processing》2014,114(3):883-889
Eu2+ and Mn2+ singly doped and codoped Na(Sr,Ba)PO4 phosphors were synthesized, and their luminescent properties were investigated. A broad blue emission and a broad orange emission band were observed in Na(Sr,Ba)PO4:Eu2+, Mn2+ phosphor. The resonant-type energy transfer from Eu2+ to Mn2+ was demonstrated, and the energy transfer efficiency was also calculated according to their emission spectra. Based on the principle of energy transfer, the emission intensity ration of Eu2+ and Mn2+ could be appropriately tuned by adjusting the contents of activators. Due to the strong absorption in the 250–400 nm range, Na(Sr,Ba)PO4:Eu2+, Mn2+ phosphor could be used as a potential candidate for near-UV white light-emitting diodes (LEDs). 相似文献
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Eu2+ single-doped and Eu2+/Mn2+-codoped Na2BaMgP2O8 phosphors were prepared by a combustion-assisted synthesis method. The phase formation was confirmed by X-ray powder diffraction measurement. Na2BaMgP2O8:Eu2+,Mn2+ shows a broad blue emission band and a red emission band, which originate from Eu2+ occupying the Ba2+ sites and Mn2+ occupying the Mg2+ sites, respectively. The efficient energy transfer from Eu2+ to Mn2+ is verified by the excitation and emission spectra together with the luminescence decay curves. Based on the principle of energy transfer, the relative intensities of blue and red emissions could be tuned by adjusting the contents of Eu2+ and Mn2+. 相似文献
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Guifang Ju Yihua Hu Li Chen Xiaojuan Wang Lihua Hung 《Applied Physics A: Materials Science & Processing》2014,114(3):867-874
We investigate the persistent luminescence in europium-doped SrMg2(PO4)2 upon codoping with auxiliary terbium. Luminescence properties of the phosphors, including photoluminescence, luminescence decay and thermoluminescence, are systematically studied. SrMg2(PO4)2:Eu2+ shows only a weak persistent luminescence, and codoping with Tb3+ is necessary to obtain considerable persistent luminescence. An energy level scheme is constructed to convey reasonable trapping and detrapping processes in the material. 相似文献
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Enhai Song Weiren Zhao Xihua Dou Yanjuan Zhu Shuangping Yi Huachu Min 《Journal of luminescence》2012,132(6):1462-1467
A series of color tunable phosphors K2Ca1?x?yP2O7:xMn2+, yEu3+ are synthesized by solid state reaction method. The energy transfer phenomenon from Mn2+ to Eu3+ has been observed in the Mn2+/Eu3+ codoped non-magnetic K2CaP2O7 host, which was confirmed by PL spectra and decay curves. The Mn2+→Eu3+ energy transfer is controlled by quadrupole–quadrupole interaction between sensitizer and activator. The maximum efficiency of energy transfer is estimated to be 33% with x=0.125 and y=0.03 in K2Ca1?x?yP2O7:xMn2+, yEu3+ phosphor. The phosphors can emit light from green to yellow and eventually to orange under 400 nm excitation by changing the Mn2+/Eu3+ content ratio, indicating that K2CaP2O7: Mn2+, Eu3+ would be potential candidates for use in lighting and displays applications. 相似文献
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Shinnosuke Kamei Yoshiyuki Kojima Nobuyuki Nishimiya 《Journal of luminescence》2010,130(11):2247-2250
This study reports the synthesis of novel red-emitting Eu3+-activated amorphous alkaline earth silicate phosphors with high emission intensities. Eu3+-activated barium (strontium) silicate hydrate phosphors were synthesized using a liquid phase reaction and then heated at 850 °C for 0.5 h to form amorphous barium (strontium) silicate phosphors. These amorphous phosphors emitted in the red region following near-UV (395 nm) irradiation. The internal quantum efficiencies of the Eu3+-activated amorphous barium silicate phosphor and strontium silicate phosphor were 56% and 60%, respectively, even though these phosphors were in the amorphous state. 相似文献
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Nd3+, Sm3+ and Eu3+ have been intercalated by cation exchange into CdPS3. The photoluminescence and IR spectra show the creation of cadmium cation vacancies. Crystal field analysis indicates that the rare earths have entered the intralamellar vacancies and formed a complex defect center with C2 or lower symmetry. 相似文献
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采用溶胶凝胶法制备了Sr3Al2O6:Eu2+,Dy3+红色长余辉发光材料,利用X射线衍射仪对材料的物相进行了分析,结果表明,1200℃下制备的样品的物相为Sr3Al2O6,少量的Eu和Dy掺杂没有影响样品的相组成.采用荧光分光光度计、照度计测定了样品的发光特性.结果表明Sr3Al2O6:Eu2+和Sr3Al2O6:Eu2+,Dy3+的激发光谱均为激发峰位于473 nm的宽带谱.Sr3Al2O6:Dy3+的发射峰位于530.1 nm,对应于Dy3+代替Sr2+位置后基质中形成的施主-受主对Dy·Sr-V″Sr的重新组合.Sr3-0.02-yAl2O6:0.02Eu2+,yDy3+(0相似文献
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The red-emitting phosphor In2(MoO4)3:Eu3+ with cubic crystal structure was synthesized by a conventional solid-state reaction technique and its photoluminescence properties were investigated. The prepared phosphor can be efficiently excited by ultraviolet (395 nm) and blue (466 nm) light. The emission spectra of the phosphor manifest intensive red-emitting lines at 612 nm due to the electric dipole 5D0→7F2 transitions of Eu3+. The chromaticity coordinates of x=0.63, y=0.35 (λex=395 nm) and x=0.60, y=0.38 (λex=466 nm) are close to the standard of National Television Standard Committee values (NTSC) values. The concentration quenching of In2(MoO4)3:Eu3+ is 40 mol% and the concentration self-quenching mechanism under 466 nm excitation was the dd intereaction. As a result of the strong emission intensity and good excitation, the phosphor In2(MoO4)3:Eu3+ is regarded as a promising red-emitting conversion material for white LEDs. 相似文献
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采用高温固相法成功合成了单一相的Eu3+,Bi3+共掺的Mg5SnB2O10红色荧光粉,并通过X射线衍射、漫反射光谱、光致发光光谱等手段对该体系的结构及其发光特性进行了测试和研究.激发光谱表明,该荧光粉在393 nm呈现Eu3+的7Fo—5L6特征激发,可以与用于发光二极管的近紫外芯片很好地匹配.在393 nm激发下,其发射光谱在591,612,701 nm处呈现Eu3+的5Do—7F1,5Do—7F2,5D0—7F4的特征发射.并且当固定Eu3+的浓度时,随着Bi3+含量的增加,发现Bi3+,Eu3+在这一体系中存在能量传递现象,系列样品发光强度大幅度提高.通过研究系列样品在不同Bi3+,Eu3+掺杂浓度下的发光性能,得出最佳样品为Mg4.89Eu0.1Bi0.01SnB2O10,其积分强度达到了商用Y2O2S:Eu3+的1.1倍. 相似文献
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利用高温熔融法制备了Li+掺杂Tb3+激活硅酸盐闪烁玻璃。通过Li+掺杂Tb3+激活硅酸盐玻璃的紫外可见透射光谱、发射光谱和发光衰减时间谱,研究了Li+的加入对Tb3+掺杂硅酸盐玻璃发光性能的影响。结果表明:适量Li+的加入可有效增强Tb3+激活硅酸盐玻璃的发光强度,且相比于不掺杂Li+的Tb3+掺杂硅酸盐玻璃而言,当掺入质量分数为2.0%的Li+时,Tb3+在玻璃中的最佳掺杂质量分数由12.8%提高至15.3%。其原因是Li+掺杂增加了玻璃体系中非桥氧的数量,从而有利于改善Tb3+在玻璃体中的均匀性,降低Tb3+间因非辐射跃迁而引起的能量损失,以及提高Tb3+的最佳掺杂质量分数。但当掺入Li+的质量分数超过2.0%时,会对Tb3+激活硅酸盐玻璃的闪烁光强产生负面影响,这是因为过多的非桥氧阻碍了X射线激发能达到Tb3+离子的能量传递。 相似文献
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用高温固相法合成了Eu2+,Mn2+共激活的Ca2SiO3Cl2高亮度白色发光材料,并对其发光性质进行了研究.该荧光粉在近紫外光激发下发出强的白色荧光,Eu2+中心形成峰值为419 nm和498 nm的特征宽带,通过Eu2+中心向Mn2+中心的能量传递导致了峰值为578 nm的发射,三个谱带叠加从而在单一基质中得到了白光.激发光谱均分布在250-415 nm的波长范围,红绿蓝三个发射带的激发谱峰值分别位于385 nm,412 nm,370 nm和396 nm处,可以被InGaN管芯产生的紫外辐射有效激发.Ca2SiO3Cl2:Eu2+,Mn2+是一种很有前途的单一基质白光LED荧光粉. 相似文献
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采用高温固相法合成了Ca2 SnO4∶Tb3+绿色荧光粉.利用X射线衍射分析了Ca2 SnO4∶Tb3+物相的形成.测量了Ca2 SnO4∶Tb3+的激发和发射光谱,激发光谱由一个宽激发峰组成,研究了Tb3+浓度对样品激发光谱的影响,结果显示,随Tb3+浓度增大,宽带激发峰发生了红移.发射光谱由四个主要发射峰组成,峰值... 相似文献
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Zhang Yugeng 《光谱学快报》2013,46(8):1479-1484
The complexes crystals of Sm(Ac)3.4H2O, Eu(Ac)3.4H2O and a new complex Dy2(Ac)(NO3)4.12H2O were synthesized and their PA spectra were determined firstly. All their PA spectra absorptions are interpreted. The fluorescence properties of Sm3+, Eu3+, Dy3+ and the relaxation process models were studied by their PA spectra. 相似文献