共查询到20条相似文献,搜索用时 11 毫秒
1.
R. Capelletti A. Baraldi E. Buffagni M. Mazzera N. Magnani E. Martin Rodriguez 《光谱学快报》2013,46(5):382-388
ABSTRACT Crystal field absorption and emission spectra originated by 5I8 ? 5F5 transitions, due to Ho3+ (1% molar fraction) in a YPO4 single crystal, were investigated in the 15000 to 16000 cm?1 range. Fourier Transform high resolution absorption measurements, performed in the 9 to 300 K range, and photoluminescence, monitored at 10 K upon 540 nm excitation, supplied the sublevel separations within both 5I8 and 5F5 manifolds. The sublevel positions were compared to those calculated by diagonalization of the full 4f-configuration matrix in the framework of a single-ion model. The results are discussed also in relation with experimental data previously reported for similar systems containing Ho3+. 相似文献
2.
Chenxia Li Shiqing Xu Rengguang YeDegang Deng Youjie HuaShilong Zhao Songlin Zhuang 《Physica B: Condensed Matter》2011,406(9):1698-1701
Ho3+/Tm3+/Yb3+ tri-doped glass ceramics with white light emitting have been developed and demonstrated. Pumped by 980 nm laser diode (LD), intensive red, green and blue up-conversions (UC) were obtained. The green emission is assigned to Ho3+ ion and the blue emission is assigned to Tm3+ ion, whereas the red emission is the combination contribution of the Ho3+ and Tm3+ ions. The RGB intensities could be adjusted by tuning the rare-earth ion concentration and pump power intensity. Thus, multicolor of the luminescence, including perfect white light with CIE-X=0.329 and CIE-Y=0.342 in the 1931 CIE chromaticity diagram can be obtained in 0.15 Ho3+/0.2Tm3+/3Yb3+ tri-doped glass ceramics embedding BaF2 nanocrystals pumped by a single infrared laser diode source of 980 nm at 500 mW. The up-conversion luminescence mechanism of Yb3+ sensitize Ho3+ and Tm3+ ions and the energy transfer from Ho3+ to Tm3+ in oxy-fluoride silicate glass ceramics were analyzed. 相似文献
3.
采用高温熔融法制备了单掺Tm3+和Tm3+/Ho3+共掺碲酸盐玻璃,测试了808 nm激光泵浦下玻璃的红外和上转换荧光光谱。Tm3+/Ho3+共掺碲酸盐玻璃上转换荧光光谱主要由695 nm红光、544 nm绿光、474 nm蓝光和740 nm红光四个发光带组成。通过分析样品的光谱性能和能量转换机制,发现很少报道的740 nm红光可能是由Tm3+:1D2 →3F2, 3能级跃迁产生的。在掺杂0.5 mol% Tm2O3的样品中添加0.3 mol% Ho2O3,695 nm红光、740 nm红光和474 nm蓝光等上转换发光强度明显增大,大约分别是单掺0.5 mol% Tm2O3样品中发光强度的3倍,2.5倍和14倍。这些情况说明存在着强烈的Ho3+→Tm3+反向能量传递。单掺Tm3+碲酸盐玻璃中1D2能级(发射740 nm红光)上的粒子集居主要来源于合作上转换(CU)过程,而3F2, 3能级(发射695 nm红光)上的粒子集居除了来源于CU过程之外,还有740 nm红光的发射和1G4能级上部分粒子的无辐射跃迁(1G4→3F2, 3)两条途径,因此样品中695 nm红光强度明显要大于740 nm红光强度。通过交叉驰豫作用CR2和CR3以及反向共振能量转移RET2,Tm3+/Ho3+共掺碲酸盐玻璃中Tm3+的1G4能级(发射474 nm蓝光)上的粒子集居数比单掺Tm3+时出现了净增加。Tm3+的1G4能级上粒子集居数的增加可能进一步强化了该能级的无辐射跃迁、740 nm红光的发射以及CU过程,并进而促使Tm3+的3F2, 3能级上的粒子集居。所以,当Tm3+/Ho3+共掺碲酸盐玻璃与单掺Tm3+碲酸盐玻璃中掺杂相同浓度的Tm3+时,前者的红光和蓝光等上转换荧光强度均比后者要大。本文还研究了Tm3+之间以及Tm3+与 Ho3+之间的交叉弛豫和能量传递等效应,并进一步探讨了Tm3+与 Ho3+之间的能量转换机制。 相似文献
4.
Vijay Singh R.P.S. Chakradhar Isabelle Ledoux-Rak Laurent Badie Fabienne Pelle Svetlana Ivanova 《Journal of luminescence》2009,129(11):1375-1380
New near-infrared luminescent, monoclinic CaAl2O4:Er3+ phosphor was prepared by using the combustion route at furnace temperatures as low as 500 °C in a few minutes. Combustion synthesized phosphor has been well characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive analysis of X-ray (EDAX) mapping studies. The luminescence spectra of Er3+-doped calcium aluminate were studied at UV (380 nm), vis (488 nm) and IR (980 nm) excitation. Upon UV and vis excitation, the CaAl2O4:Er3+ phosphor exhibits emission bands at ~523 nm and at ~547 nm, corresponding to transitions from the 2H11/2 and 4S3/2 erbium levels to the 4I15/2 ground state. A strong luminescence at 1.55 μm in the infrared (IR) region due to 4I13/2→4I15/2 transition has been observed in CaAl2O4:Er3+ phosphor upon 980 nm CW pumping. In the spectrum of IR-excited up-conversion luminescence, green (~523 and ~547 nm) and red (662 nm) luminescence bands were present, the latter associated with the 4F9/2→4I15/2 transitions of Er3+ ions. Both excited state absorption and energy transfer may be proposed as processes responsible for the population of the 4S3/2 and 4F9/2 erbium levels upon IR excitation. The mechanisms responsible for the up-conversion luminescence are discussed. 相似文献
5.
The Yb3+/Tm3+ co-doped GdF3 and NaGdF4 samples were synthesized through a combination method of a co-precipitation and an argon atmosphere annealing procedures. X-ray diffraction analysis indicated that the Yb3+/Tm3+ co-doped GdF3 sample crystallized well and was orthorhombic phase, and the Yb3+/Tm3+ co-doped NaGdF4 sample was hexagonal phase. With a 980-nm semiconductor continuous wave laser diode as the excitation source, the up-conversion emission spectra of the two samples in the wavelength range of 240-510 nm were recorded. In the up-conversion emissions of the samples, Yb3+ transferred energies to Tm3+ resulting in their ultraviolet, violet, and blue up-conversion emissions. And, Tm3+ simultaneously transferred energies to Gd3+, which finally resulted in ultraviolet up-conversion emissions of Gd3+. The study on the excitation power dependence of up-conversion fluorescence intensity indicated that there were multi-photon (three-, four-, five-, and six-) processes in the up-conversion emissions of the samples. And the up-conversion emissions of Gd3+ and Tm3+ in the Yb3+/Tm3+ co-doped GdF3 and NaGdF4 samples were compared studied, too. 相似文献
6.
This paper studies the upconversion luminescence phenomenon of the Ho,Yb co-doped oxyfluoride vitroceramics. There is one group of strong upconversion luminescence lines positioned at 536.5nm, 18639cm-1; 540.5nm, 18501cm-1; 544.0nm, 18399cm-1, which is easily identified as the transitions of 5S2→5I8. There are other splendid upconversion luminescence lines, which are 5S2→5I7,5F5→5I8,5G6→5I8, (5G3G)5 →5I8,(3F3H5G)4→5I7,5G4→5I8 and (5G3H)5→5I8. It is also found that an interesting kind of upconversion cooperative radiation fluorescence comes from a kind of coupling state of clusters consisting of two Yb3+ ions. 相似文献
7.
报道了Tm3+/Ho3+共掺的镓铋酸盐玻璃14Ga2O3-25Bi2O3-20GeO2-31PbO-10PbF2玻璃1.47μm(S波段)发光和能量传递特征,应用Judd-Ofelt理论计算了玻璃的强度参数Ωt(t=2,4,6),自发辐射概率A、荧光分支比β,荧光辐射寿命τ等各项光谱参数以及有效荧光线宽Δλeff和峰值发射截面σpeake.通过测量荧光光谱和荧光寿命研究了Ho3+离子掺杂浓度对Tm3+离子1.47μm波段发光性能的影响,分析了Tm3+和Ho3+之间的能量传递过程.结果表明一定浓度内Ho3+的共掺迅速降低了Tm3+:3F4能级的粒子数,而对3H4能级粒子数影响不大,从而降低了3F4和3H4能级间布居数反转的难度,极大地提高了1.47μm发光效率.研究表明镓铋酸盐玻璃是适用于S波段光纤放大器的一种潜在基质材料,而掺杂一定浓度的Ho3+离子有利于提高Tm3+离子在1.47μm波段的发光效率.
关键词:
重金属氧化物玻璃
光谱性质
3+/Ho3+离子')" href="#">Tm3+/Ho3+离子
能量传递 相似文献
8.
Electronic structure and optical properties of the Ce3? in YAG has been investigated by standard spectroscopy (photoluminescence, absorption and excitation spectra) and high pressure spectroscopy. The bandshape of the emission spectrum for different pressures has been analyzed and influence of pressure on energy of the 5d1 states and the electron-lattice coupling have been determined. The significant red shift of the peak of the emission band (the respective pressure coefficient has been equal to—12cm?1/kbar) has been obtained. The shift has been understood by taking into account pressure induced increase of the 5d1 level splitting and increase of the electron-lattice coupling strength. 相似文献
9.
We investigate the up-conversion luminescence spectra of Ho3+-Yb3+ co-doped materials excited with two types of laser. It is found that the efficiency of green emission (5S2-5I8) can be enhanced by restraining the transition of 5S2-5I7 since the two types of radiation both start on the 5S2 level. We propose an important approach to enhance an expected up-conversion emission. 相似文献
10.
The up-conversion emission properties of Yb3+-Ho3+ co-doped germanium-borate glasses have been investigated with 980 nm excitation. The violet, blue, green and red emission bands at about 350, 485, 544 and 653 nm can be identified, respectively. Experimental results indicated that the relative intensity ratios of the peaks IRed/IGreen increased with increasing B2O3 concentration, which led to changing color of up-conversion emission from green at x=0 to yellow at x=40, to red at x=60. The violet emission at 350 nm was first reported in germanium-borate glass host and up-conversion mechanisms of the emissions were discussed. The Yb3+-Ho3+ co-doped germanium-borate glasses could be an alternative for the generation of violet and primary colors for application in solid-state displays. 相似文献
11.
J. Méndez-Ramos V. Lavín I. R. Martín U. R. Rodríguez-Mendoza V. D. Rodríguez A. D. Lozano-Gorrín 《辐射效应与固体损伤》2013,168(1-6):457-462
Optical properties of Eu3? ions in oxyfluoride glasses and glass ceramics doped with low concentration (0.1 mol%) have been analysed and compared with previous results for high concentrated samples (2.5 mol%). The Eu3? ions in the low dopant concentration glass ceramics are diluted into like crystalline environments with higher symmetry and lower coupled phonons energy than in the precursor glasses. Fluorescence line narrowing measurements indicate the presence of two main fluoride site distributions for the Eu3? ions in these low concentrated glass ceramics. 相似文献
12.
采用熔融冷却法制备了系列Ho3+/Pr3+共掺的Ge25Ga10Se65玻璃样品,测试了样品的吸收光谱以及908 nm激光抽运下的中红外荧光光谱和Ho3+离子5I7能级寿命.计算了Ho3+:5I7→5I8发射截面和Pr3+:3H4→3F2吸收截面,讨论了Ho3+,Pr3+离子之间的能量转移效率及Pr3+离子浓度的影响.通过拟合Ho3+离子2.0 μm荧光衰减曲线判断能量转移机理.结果表明,Ho3+掺杂Ge25Ga10Se65玻璃中引入Pr3+离子可以有效提高Ho3+离子的2.9 μm荧光强度.
关键词:
中红外发光
硫系玻璃
3+/Pr3+共掺')" href="#">Ho3+/Pr3+共掺 相似文献
13.
采用高温熔融法制备了组分为TeO2-ZnO-Na2O的Tm3+离子单掺和Tm3+/Yb3+共掺碲酸盐玻璃,应用Judd-Ofelt理论计算分析了玻璃样品的强度参量Ωt(t=2, 4, 6),自发辐射跃迁几率A,荧光分支比β和荧光辐射寿命τrad等光谱参量,测量得到了不同Yb3+离子掺杂浓度下玻璃样品的Tm3+离子上转换发光谱.结果显示,在980 nm泵浦光激励下玻璃样品发射出强烈的近红外上转换荧光.对Tm3+离子上转换发光分析表明,强烈的Tm3+离子近红外上转换发光主要来自于Yb3+/Yb3+离子间的共振能量传递以及基于单声子和双声子辅助的Yb3+/Tm3+离子间的非共振能量传递过程,并进一步计算得到了声子贡献比和能量传递系数.最后,计算分析了Tm3+:3F4→3H6能级间跃迁的1.8 μm波段吸收截面、受激发射截面和增益系数.研究表明,Yb3+/Tm3+共掺TeO2-ZnO-Na2O玻璃可以作为近红外波段固体激光器的潜在增益基质. 相似文献
14.
Low phonon energy Tm3+/Ho3+/Yb3+ triply doped bismuth tellurite glasses exhibiting multicolor upconversion fluorescences have been fabricated and characterized. The multicolor fluorescence composed of three primary colors green, red and blue upconversion emissions from Ho3+ and Tm3+ has been investigated. By adjusting the excitation power, the fluorescence colors can be tuned from multicolor to white color, and the dependence of color tunability on pump power has been presented in the CIE 1931 chromaticity diagram. With the increase in pumping power, the color coordinates move along the down-left direction and hit the equal energy point. The upconversion and color tunability via changing the pump power of infrared excitation in Tm3+/Ho3+/Yb3+ triply doped bismuth tellurite glasses will lead to new breakthrough in the field of three-dimensional solid-state displays and white-light emitting devices. 相似文献
15.
16.
在Er3+/Yb3+共掺TeO2-WO3-ZnO玻璃中引入Ce3+,研究了Ce3+对Er3+1.5μm发射性能及其上转换发光性能的影响。结果表明,随Ce3+浓度的增加Er3+1.5μm波段的荧光强度先增强后降低,优化的Ce3+掺杂浓度在2.07×1020/cm3左右;1.5μm波段的荧光寿命则随Ce3+浓度的增加有轻微降低,从3.4ms降到3.0ms,但Ce3+浓度的增加对1.5μm波段的荧光半高宽基本无影响;Er3+/Ce3+间的交叉弛豫Er3+(4I11/2)+Ce3+(2F5/2)→Er3+(4I13/2)+Ce3+(2F7/2)使玻璃的上转换发光强度大大降低,但在过高的Ce3+浓度下,Er3+/Ce3+间的另一交叉弛豫Er3+(4I13/2)+Ce3+(2F5/2)→Er3+(4I15/2)+Ce3+(2F7/2)则使Er3+4I13/2能级粒子数减少,导致1.5μm波段荧光强度和荧光寿命降低.
关键词:
碲钨酸盐玻璃
发光性能
3+离子')" href="#">Er3+离子
3+离子')" href="#">Ce3+离子
交叉弛豫 相似文献
17.
V. Vaicikauskas R. Antanavicius R. Januskevicius 《International Journal of Infrared and Millimeter Waves》1999,20(3):439-445
The Surface Electromagnetic waves method was applied for determination of plasma frequency and pulse relaxation time in doped A3B5 semiconductors. The influence of plasmon phonon interaction, nonparabolity of the conduction band, electron scattering peculiarities, presence of disturbed layers are under consideration. 相似文献
18.
用高温熔融法制备了Tm3+/Ho3+/Yb3+共掺碲酸盐玻璃(TeO2-ZnO-La2O3)样品,测试了玻璃样品的吸收光谱和上转换发光光谱,分析了上转换发光机理.结果发现:在975 nm波长激光二极管(LD)激励下,制备的碲酸盐玻璃样品可以观察到强烈的红光(662 nm)、绿光(546 nm)和蓝光(480 nm)三基色上转换发光,红光对应于Tm3+离子
关键词:
碲酸盐玻璃
上转换发光
白光
3+/Ho3+/Yb3+共掺')" href="#">Tm3+/Ho3+/Yb3+共掺 相似文献
19.
T. Satyanarayana 《Journal of luminescence》2010,130(3):498-506
The glasses of the composition (39−x)BaO-xAl2O3-60P2O5:1.0Ho2O3 (in mol%) with x value ranging from 1.0 to 4.0 have been synthesized. The IR spectral studies of these glasses have indicated that there is a gradual transformation of Al3+ ions from tetrahedral to octahedral with increase in the concentration of Al2O3 up to 3.0 mol%. Optical absorption and fluorescence spectra (in the visible and NIR regions) of these glasses have been recorded at room temperature. The Judd-Ofelt theory could successfully be applied to characterize the absorption and luminescence spectra of Ho3+ ions in these glasses. From the luminescence spectra, various radiative properties like transition probability A, branching ratio βr, the radiative lifetime τr and emission cross-section σE for various emission levels of these glasses have been evaluated. The radiative lifetime of the 5S2→5I8 (green emission) transition has also been measured. The variations observed in these parameters have been discussed in the light of varying co-ordinations (tetrahedral and octahedral positions) of Al3+ ions in the glass network. The influence of hydroxyl groups on the luminescence efficiency of the transition 5S2→5I8 has also been discussed. Finally the optimum concentration of Al2O3 for getting maximum luminescence output has also been identified and reported. 相似文献
20.
本文研究了808nm激光二极管抽运下掺Tm3+和Tm3+/Ho3+共掺碲酸盐玻璃的能量转换过程和机理.利用Dexter模型计算了能量转换微观参数和临界半径,分析了两者的变化特性;利用Vila等修正的Inokuti-Hirayama模型拟合了Tm3+的荧光衰减曲线.结果表明:Tm3+/Ho3+共掺碲酸盐玻璃的能量转换过程中,不仅包含Inokuti-Hirayama作用方式,而且存在着局域性相互作用,并随着Tm3+和Ho3+的浓度增大,后者所占比例逐渐增大. 相似文献