共查询到20条相似文献,搜索用时 15 毫秒
1.
Liao M Hu L Fang Y Zhang J Sun H Xu S Zhang L 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2007,68(3):531-535
Er3+, Yb3+ and Tm3+ codoped fluorophosphate glasses emitting blue, green and red upconversion luminescence at 970 nm laser diode excitation were studied. It was shown that Tm3+ behaves as the sensitizer to Er3+ for the green upconversion luminescence through the energy transfer process: Tm3+:3H4+Er3+:4I 15/2-->Er3+:4I 9/2+Tm3+:3H6, and for the red upconversion luminescence through the energy transfer process: Tm3+:3F4+Er3+:4I 11/2-->Tm3+:3H6+Er3+:4F 9/2. Moreover, Er3+ acts as quenching center for the blue upconversion luminescence of Tm3+. The sensitization of Tm3+ to Er3+ depends on the concentration of Yb3+. The intensity of blue, green and red emissions can be changed by adjusting the concentrations of the three kinds of rare earth ions. This research may provide useful information for the development of high color and spatial resolution devices and white light simulation. 相似文献
2.
在组成为15Li2O-15Nb2O5-70TeO2-0.1Er2O3-0.4Yb2O3(%, 摩尔分数)的碲酸盐玻璃基础上, 采用两步热处理法制备了透明的含纳米晶颗粒碲酸盐玻璃陶瓷. 通过X射线衍射(XRD)测试表明, 玻璃陶瓷中的晶体颗粒组成为Yb6Te5O19.2或Er6Te5O19.2, 晶粒尺寸约为55 nm. 根据Judd-Ofelt理论计算了Er^3+离子在基质玻璃和玻璃陶瓷中的光谱参数Ωt(t=2, 4, 6)以及Er^3+:4I15/2→4I13/2跃迁自发辐射几率, 根据McCumber理论计算了Er^3+:4I13/2→4I15/2跃迁的发射截面. 测试了基质玻璃和玻璃陶瓷的拉曼光谱, 对比研究了铒离子在基质玻璃和玻璃陶瓷中1.5 μm处荧光和上转换光谱特性. 相似文献
3.
Shen X Nie Q Xu T Gao Y 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2005,61(9):2189-2193
The spectral properties of Er3+/Yb3+ codoped tungsten-tellurite (WT) glasses have been investigated. The measured absorption spectra are analyzed by Judd-Ofelt theory. The compositional change of intensity parameter omega2 is attributed to the change in the covalency between the Er3+ and oxygen ions, the asymmetry in the local structures around the Er3+ ions can be neglected. The lifetimes of 4I(13/2) level of Er3+ in WT glasses are measured and comparable with other TeO2-based glasses. The stimulated emission cross-section is calculated based on McCumber theory. The fluorescence full width at half maximum (FWHM) and the emission cross-section (sigma(peak)) of the 4I(13/2) --> 4I(15/2) transition of Er3+ in different glass hosts have been compared. The suitability of such WT glasses as host materials for 1.5 microm broadband amplification is discussed. 相似文献
4.
In this work, investigation have been done on polycrystalline yttrium calcium oxyborate (YCa4O(BO3)3) for the realization of existence of second harmonic generation and other photon upconversion processes as concurrent effect with the aid of Er, Yb, Nd trivalent lanthanide ions. Pure, Er:Yb co-doped and Er:Yb:Nd triply-doped YCa4O(BO3)3 samples were prepared through solid state reaction and the phase identification has been done using powder X-ray diffraction spectral analysis. FTIR spectra show that the dopants increases the absorption of functional groups and modifies the lattice vibrational modes of YCa4O(BO3)3. The spectral overlap of optical absorption bands of Er3+, Yb3+, Nd3+ ions in 840 nm–1070 nm region indicates the prospect of energy transfer between these ions. The photoluminescence spectrum of Er:Yb:Nd triply doped sample show good enhancement compared to pure and Er:Yb co-doped YCa4O(BO3)3 samples. In the photon upconversion test carried out using 1064 nm Nd:YAG laser YCa4O(BO3)3:Er:Yb:Nd sample produced green light with efficiency higher than the other two samples. Surface morphology of the samples was recorded using field emission scanning electron microscope and analysed. The elemental composition of the samples has been confirmed by energy dispersive X-ray spectral analysis. 相似文献
5.
Study of luminescence properties of novel Er3+ single-doped and Er3+/Yb3+ co-doped tellurite glasses 总被引:2,自引:0,他引:2
Gao Y Nie QH Xu TF Shen X 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2005,61(6):1259-1262
The novel Er(3+) single-doped and Er(3+)/Yb(3+) co-doped tellurite glasses were prepared. The effect of Yb(2)O(3) concentration on absorption spectra, emission spectra and upconversion spectra of glasses were measured and investigated. The emission intensity, fluorescence full width at half maximum (FWHM) and upconversion luminescence of Er(3+) go up with the increasing concentration of Yb(3+) ions. The maximum FWHM of (4)I(13/2) --> (4)I(15/2) transition of Er(3+) is approximate 77 nm for 1.41 x 10(21)ions/cm(3) concentration of Yb(3+)-doped glass. The visible upconversion emissions at about 532, 546 and 659 nm, corresponding to the (2)H(11/2) --> (4)I(15/2), (4)S(3/2) --> (4)I(15/2) and (4)F(9/2) --> (4)I(15/2) transitions of Er(3+), respectively, were simultaneously observed under the excitation at 970 nm. Subsequently, the possible upconversion mechanisms and important role of Yb(3+) on the green and red emissions were discussed and compared. The results demonstrate that this kind of tellurite glass may be a potentially useful material for developing potential amplifiers and upconversion optical devices. 相似文献
6.
Boyer JC Vetrone F Cuccia LA Capobianco JA 《Journal of the American Chemical Society》2006,128(23):7444-7445
Upconverting lanthanide-doped nanocrystals were synthesized via the thermal decomposition of trifluoroacetate precursors in a mixture of oleic acid and octadecene. This method provides highly luminescent nanoparticles through a simple one-pot technique with only one preparatory step. The Er3+, Yb3+ and Tm3+, Yb3+ doped cubic NaYF4 nanocrystals are colloidally stable in nonpolar organic solvents and exhibit green/red and blue upconversion luminescence, respectively, under 977 nm laser excitation with low power densities. 相似文献
7.
Ratnakaram YC Kumar AV Naidu DT Rao JL 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2005,61(9):2169-2179
An investigations of the optical absorption and fluorescence spectra of 0.2 mol% Er2O3 in mixed alkali borate glasses of the type 67.8B2O3 x xLi2O(32-x)Na2O, 67.8B2O3 x xLi2O(32-x)K2O and 67.8B2O3 x xNa2O(32-x)K2O (where x = 8, 12, 16, 20 and 24) are presented. The glasses were obtained by quenching melts consisting of H3BO3, Li2CO3, Na2CO3, K2CO3 and Er2O3 (950-1100 degrees C, 1.5-2 h) between two brass plates. Spectroscopic parameters like Racah (E1, E2 and E3), spin-orbit (xi(4f)) and configuration interaction (alpha) parameters are deduced as function of x. Using Judd-Ofelt theory, Judd-Ofelt intensity parameters (omega2, omega4 and omega6) are obtained. Radiative and non-radiative transition rates (A(T) and W(MPR)), radiative lifetimes (tauR), branching ratios (beta) and integrated absorption cross-sections (sigma) have been computed for certain excited states of Er3+ in these mixed alkali borate glasses. Emission spectra have been studied for all the three Er3+ doped mixed alkali borate glasses. The present paper throws light on the trends observed in the intensity parameters, radiative lifetimes, branching ratios and emission cross-sections as a function of x in these borate glasses, keeping in view the effect of mixed alkalies in borate glasses. 相似文献
8.
Illariia A. Razumkova Yuriy G. Denisenko Andrey N. Boyko Denis A. Ikonnikov Aleksandr S. Aleksandrovsky Nikita O. Azarapin Oleg V. Andreev 《无机化学与普通化学杂志》2019,645(24):1393-1401
Rare earth fluorides are mainly obtained from aqueous solutions of oxygen‐containing precursors. Probably, this method is simple and efficient, however, oxygen may partially be retained in the fluoride structure. We offer an alternative method: obtaining fluorides and solid solutions based on them from an oxygen‐free precursor. As starting materials, we choose sulfides of rare‐earth elements and solid solutions based on them. The fluorination is carried out by exposure to hydrofluoric acid of various concentrations. The transmission electron microscopy images revealed the different morphologies of the products, which depend on the concentration of the fluorinating component (HF) and the host element. The solid solution particle size varied from 30–35 nm in the case of GdF3:Yb3+, Tm3+ (4 % HF) to larger structures with dimensions exceeding 200 nm, such as that for LaF3:Yb3+, Ho3+ (40 % HF). The thermal characteristics, such as the temperatures of the transitions and melting and enthalpies, were determined for the solid solutions and simple fluorides. Applicability of the materials obtained as biological luminescent markers was tested on the example of upconversion luminescence, and good upconversion properties were detected. 相似文献
9.
Mohan S Thind KS Sharma G Gerward L 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2008,70(5):1173-1179
Spectroscopic and physical properties of Nd(3+) doped sodium lead flouro- and chloro-borate glasses of the type 20NaX-30PbO-49.5B(2)O(3)-0.5Nd(2)O(3) (X=F and Cl) have been investigated. Optical absorption spectra have been used to determine the Slater Condon (F(2), F(4), and F(6)), spin orbit xi(4f) and Racah parameters (E(1), E(2), and E(3)). The oscillator strengths and the intensity parameters Omega(2), Omega(4) and Omega(6) have been determined by the Judd-Ofelt theory, which in turn provide the radiative transition probability (A), total transition probability (A(T)), radiative lifetime (tau(R)) and branching ratio (beta) for the fluorescent level (4)F(3/2). The lasing efficiency of the prepared glasses has been characterized by the spectroscopic quality factor (Omega(4)/Omega(6)), the value of which is in the range of 0.2-1.5, typical for Nd(3+) in different laser hosts. Nephelauxetic effect results in a red shift in the energy levels of Nd(3+) for chloroborate glass. The radiative transition probability of the potential lasing transition (4)F(3/2)-->(4)I(11/2) of Nd(3+) ions is found to be higher for flouroborate as compared to chloroborate glass. 相似文献
10.
Mithlesh Kumar A. R. Dhobale Mukesh Kumar M. D. Sastry 《Journal of Polymer Science.Polymer Physics》1997,35(1):187-192
Photoacoustic (PA) spectra of Ho3+, Er3+, and Sm3+ doped PVA films were obtained in 350–800 nm range. PA spectra were also obtained for the respective dopant oxides: Ho2O3, Er2O3, and Sm2O3 for comparison. It was found that in PVA the PA sensitivity has increased considerably compared to pure rare earth oxides. The relative intensities of absorption bands at 540 and 637 nm of Ho3+: PVA have shown distinct enhancement, indicating the increase in nonradiative relaxation at these excitations. Furthermore, the PA signals at wavelengths for different PA absorption bands were monitored as a function of chopping frequency. These experiments have shown that PA signal varies w−1 both for oxides and PVA samples, suggesting that they behave as thermally thin samples. © 1997 John Wiley & Sons, Inc. 相似文献
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采用丙三醇液相结晶法制备了NaYF4∶Er3+, Yb3+上转换纳米晶, 合成步骤被简化. 常温下, 用980 nm的红外激光激发可以观察到很强的绿光、红光发射, 用荧光光谱仪记录了该上转换光谱. X射线粉末衍射(XRD)结果表明, 该方法制备NaYF4∶Er3+, Yb3+纳米晶属于立方混合六方晶系. 研究了纳米晶的上转换发光机理, 根据晶体场理论对Er3+的两个上转换能级进行了Stark分裂计算, 对两个能级之间的谱线进行了归属, 进一步证实了980 nm光子激发Er3+离子的上转换机理, 一个是连续吸收两个980 nm光子的过程(激发态吸收), 另一个是吸收980 nm光子后, 电子转移到亚稳态能级, 然后再吸收980 nm光子过程(能量转移上转换). 相似文献
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14.
《Solid State Sciences》2012,14(2):287-290
Transparent glass-ceramics with Yb3+, Er3+ ions in glass matrix and tetrahedral Co2+-doped MgAl2O4 nanocrystals were synthesized. XRD patterns and FESEM micrograph of the glass-ceramics showed that MgAl2O4 nanocrystals (sizes of 10–20 nm) are uniformly dispersed in SiO2 glass matrix. Absorption and emission spectra of the glass-ceramics indicated that Yb3+, Er3+ remain in SiO2 glass matrix, while Co2+ occupied tetrahedral sites in MgAl2O4 nanocrystals, and can function as saturable absorber for Er3+. Transparent Co2+, Yb3+, Er3+ co-doped glass-ceramics possesses the spectral requirements and should be a potential laser material used for self-Q-switched microchip laser operating at 1.5–1.6 μm. 相似文献
15.
A series of novel Er3+/Yb3+ co-doped 75TeO2-(25-x)Nb2O5-xWO3 (TNW: x=0, 3, 6, 9, 12, and 15 mol%) glasses have been prepared. Effect of WO3 on the thermal stability and spectroscopic properties of Er3+/Yb3+ co-doped niobic tellurite glasses have been investigated. With WO3 content increasing from 0 to 15 mol%, the fluorescence full width at half maximum (FWHM), the peak of stimulated emission cross-section (sigmaepeak), the measured lifetime (taum), and quantum efficiency (eta) change from 71 nm, 8.47x10(-21) cm2, 2.86 ms, 84.1% to 76 nm, 7.22x10(-21) cm2, 3.14 ms, 88.9%, respectively. The FWHM and sigmaepeak of Er3+ ions in different glass hosts were compared; the obtained data reveals that this new TNW4 glass may be a potentially useful candidate material host for broadband amplifiers. 相似文献
16.
Lu L Nie Q Shen X Dai S Xu T Jin Z Shen Y Zhang X 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2007,67(5):1228-1231
The absorption and upconversion fluorescence spectra of a series of Er3+/Yb3+-codoped xBi(2)O(3)-(90-x)GeO2-10Na(2)O (BGN x, x=31, 36, 41, 46 and 51 mol%) glasses have been studied. Intense green and red emission bands at around 533, 548 and 659 nm, corresponding to the 2H(11/2)-->4I(15/2), 4S(3/2)-->4I(15/2) and 4F(9/2)-->4I(15/2) transitions of Er3+, respectively, were simultaneously observed at room temperature. The dependence of intensities of upconversion emission on excitation power and possible upconversion mechanisms were evaluated and analyzed. The important role of Bi(2)O(3) in upconversion intensity is observed and its influence on the green (533 and 548 nm) and red (659 nm) emissions is compared and discussed. The influence of Bi(2)O(3) on the upconversion emissions has been investigated based on the IR spectra. 相似文献
17.
采用1,3-丁二醇低热结晶法制备了ZrO2∶Er3+,Yb3+纳米晶.常温下,用980nm的红外激光激发可以观察到很强的ZrO2∶Er3+,Yb3+纳米晶红光发射,用荧光光谱仪记录了该上转换光谱.X射线粉末衍射(XRD)结果表明,ZrO2∶Er3+,Yb3+纳米晶属于立方晶系.研究了纳米晶的上转换发光机理,根据晶体场理论对Er3+的2个上转换能级进行了Stark分裂计算,对2个能级之间的谱线进行了归属,进一步证实了980nm激发Er3+离子的上转换经历两个过程:一是连续吸收2个980nm光子的过程,二是吸收980nm光子,电子转移到亚稳态能级后,再吸收980nm光子的过程 相似文献
18.
双掺Er3+,Yb3+离子KY(WO4)2晶体的光谱性质 总被引:9,自引:5,他引:9
研究分析了用助熔剂法生长的Er^3 /Yb^3 :KY(WO4)2晶体在室温下的吸收光谱和发射光谱,在吸收谱的350-1750nm区域,除了900-1050nm的谱带是Er^3 ,Yb^3 的共同谱带,其他的都属于Er^3 的谱带,用266nm激发时产生540-560,660-680,850-870,1450-1600nm四个发射带,用976nm激发时产生的主要是Er^3 的1450-1600nm发射带,这两 的能量转移机制不相同。 相似文献
19.
Sanghi S Pal I Agarwal A Aggarwal MP 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,83(1):94-99
Glasses with composition 20CdO·xBi(2)O(3)·(79.5-x)B(2)O(3) (15≤x≤35, x in mol%) containing 0.5 mol% of Er(3+) ions were prepared by melt-quench technique (1150°C in air). The amorphous nature of the glasses was confirmed by X-ray diffraction. The spectroscopic properties of the glasses were investigated using optical absorption spectra and fluorescence spectra. The phenomenological Judd-Ofelt intensity parameters Ω(λ) (λ=2, 4, 6) were determined from the spectral intensities of absorption bands in order to calculate the radiative transition probability (A(R)), radiative life time (τ(R)), branching ratios (β(R)) for various excited luminescent states. Using the near infrared emission spectra, full width at half maxima (FWHM), stimulated emission cross-section (σ(e)) and figure of merit (FOM) were evaluated and compared with other hosts. Especially, the numerical values of these parameters indicate that the emission transition (4)I(13/2)→(4)I(15/2) at 1.506 μm in Er(3+)-doped cadmium bismuth borate glasses may be useful in optical communication. 相似文献
20.
Multicolor Lu(2)O(3):Ln (Ln=Eu(3+), Tb(3+), Yb(3+)/Er(3+), Yb(3+)/Tm(3+), and Yb(3+)/Ho(3+)) nanocrystals (NCs) with uniform spherical morphology were prepared through a facile urea-assisted homogeneous precipitation method followed by a subsequent calcination process. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectrum (EDS), Fourier transformed infrared (FT-IR), thermogravimetric and differential thermal analysis (TG-DTA), and photoluminescence (PL) spectra as well as kinetic decays were employed to characterize these samples. The XRD results reveal that the as-prepared nanospheres can be well indexed to cubic Lu(2)O(3) phase with high purity. The SEM images show the obtained Lu(2)O(3):Ln samples consist of regular nanospheres with the mean diameter of 95 nm. And the possible formation mechanism is also proposed. Upon ultraviolet (UV) excitation, Lu(2)O(3):Ln (Ln=Eu(3+) and Tb(3+)) NCs exhibit bright red (Eu(3+), (5)D(0)→(7)F(2)), and green (Tb(3+), (5)D(4)→(7)F(5)) down-conversion (DC) emissions. Under 980 nm NIR irradiation, Lu(2)O(3):Ln (Ln=Yb(3+)/Er(3+), Yb(3+)/Tm(3+), and Yb(3+)/Ho(3+)) NCs display the typical up-conversion (UC) emissions of green (Er(3+), (4)S(3/2),(2)H(11/2)→(4)I(15/2)), blue (Tm(3+), (1)G(4)→(3)H(6)) and yellow-green (Ho(3+), (5)F(4), (5)S(2)→(5)I(8)), respectively. 相似文献