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1.
Degang Deng Shiqing Xu Shilong Zhao Chenxia Li Huanping Wang Haidong Ju 《Journal of luminescence》2009,129(11):1266-1270
A transparent Er3+–Tm3+–Yb3+ tri-doped oxyfluoride glass ceramics containing LiYF4 nanocrystals were prepared. Under 980 nm laser diode (LD) pumping, intensive red, green and blue upconversion (UC) was obtained. The blue, green, and red UC radiations correspond to the transitions 1G4→3H6 of Tm3+, 2H11/2/4S3/2→4I15/2, and 4F9/2→4I15/2 of Er3+ ions, respectively. This is similar to that in Tm3+–Yb3+ and/or Er3+–Yb3+ co-doped glass ceramics. However, the blue UC radiations of the Er3+–Yb3+ co-doped glass ceramics is two-photon process due to cooperative energy transfer. The UC mechanisms were proposed based on spectral, kinetic, and pump power dependence analyses. 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.
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
4.
Novel Ba2ErF7 and Yb3+-doped Ba2ErF7 powders were synthesized by a coprecipitation method. In Ba2ErF7 sample, abundant upconverted emission bands from violet to infrared region are observed under 980 nm excitation, whereas only green and red emissions are observed under 812 nm excitation. Under the two excitations, the luminescence decay curves of the green and red emissions are measured and the quenching behaviors of Yb3+ doping are also explored. It is found that a suitable Yb3+ concentration can efficiently enhance the intensity ratio of the blue and violet emissions to the green and red ones, which may be due to the competition between the energy transfer process from Er3+ to Yb3+ and the sensitizing process from Yb3+ to Er3+ in Ba2ErF7:Yb3+. This indicates that the Yb3+-doped Ba2ErF7 might be a good candidate for blue and violet upconversion phosphor. 相似文献
5.
Spectroscopic properties and mechanism of Tm^3+/Er^3+/Yb^3+ co-doped oxyfluorogermanate glass ceramics containing BaF2 nanocrystals
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Transparent Tm^3+/Er^3+/yb^3+ co-doped oxyfluorogermanate glass ceramics containing BaF2 nanocrystals are prepared. Under excitation of a 980-nm laser diode (LD), compared with the glass before heat treatment, the Tm^3+/Er^3+/yb^3+ co-doped oxyfluorogermanate glass ceramics can emit intense blue, green and red up-conversion luminescence and Stark- split peaks; X-ray diffraction (XRD) and transmission electron microscope (TEM) results show that BaF2 nanocrystals with an average diameter of 20 nm are precipitated from the glass matrix. Stark splitting of the up-conversion luminescence peaks in the glass ceramics indicates that Tm^3+, Er^3+ and (or) Yb^3+ ions are incorporated into the BaF2 nanocrystals. The up-conversion luminescence intensities of Tm^3+, Er^3+ and the splitting degree of luminescence peaks in the glass ceramics increase significantly with the increase of heat treat temperature and heat treat time extension. In addition, the possible energy transfer process between rare earth ions and the up-conversion luminescence mechanism are also proposed. 相似文献
6.
In this work, we used the hydrothermal method to synthesize Yb3+ and Tm3+ doped LaF3 nanostructures, which is an ultraviolet upconversion luminescent material. Two distinct shapes such as nanosheets, nanoparticles and bulk samples formed in the products by adjusting the concentrations of the surfactant of the reaction solution. Powder X-ray diffraction analysis showed that the products were pure hexagonal phase, while electron microscopy measurements confirm the formation of different morphologies. These nanostructures exhibit strong ultraviolet upconversion luminescence under the excitation of a 978-nm diode laser. In Yb3+ and Tm3+ codoped LaF3 materials, the relative intensity of ultraviolet and blue upconversion emissions became stronger as the size and morphology of sample changed from bulk to sheets. 相似文献
7.
ZrO2:Tb3+ and BaZrO3:Tb3+ powders are prepared by combustion synthesis method and the samples were further heated to 500, 700 and 1000 °C to improve the crystallinity of the materials. The structure and morphology of materials have been examined by X-ray diffraction, Raman spectra and scanning electron microscopy. It is remarkable that all the samples of ZrO2:Tb3+ and BaZrO3:Tb3+ have similar morphology. These images exhibited homogeneous aggregates of varying shapes and sizes, which are composed of a large number of small cuboids and broken cuboids. The cuboids and broken cuboids size of all the samples are less than 0.5 μm. Photoluminescence for both materials increases with increase of temperature and found maximum for the samples heated to 1000 °C with 5 mole% doping of Tb3+ ions. Luminescence is almost double for the zirconia compared to that of barium-zirconate. 相似文献
8.
Using the combustion synthesis, CaYAl3O7:Er3+ phosphor powders co-doped with Yb3+ have been prepared at low temperatures (550 °C) in a few minutes. Formation of the compound was confirmed by X-ray powder diffraction. Near-infrared to visible upconversion fluorescence emission in the Er3+ doped CaYAl3O7 phosphor powder has been observed. The effect of co-doping with triply ionized ytterbium in the CaYAl3O7:Er3+ phosphor has been studied and the process involved is discussed. 相似文献
9.
Transparent glass-ceramics have been fabricated by heat treatment with 1.0 mol% Tb2O3-doped 45SiO2-20Al2O3-10CaO-25CaF2 aluminosilicate glass. The precipitated crystalline phase in the glass-ceramics is CaF2 nanocrystals with a size of 15-27 nm and dispersed in the amorphous phase. Both photo- and radioluminescence measurements show that the increase of Tb3+ 545 nm line intensity by a factor of 4 and 3.5 is obtained in glass-ceramics with respect to the as-made glass, respectively. 相似文献
10.
Chengguo Ming Yin Yu Gong Zhang Qingru Wang Hua Yu Tongqing Sun Jianguo Tian 《Optics Communications》2011,284(7):1868-1871
The up-conversion (UC) and near infrared (NIR) luminescence of Er3+/Yb3+ co-doped phosphate glass are investigated. In the UC emission range, the 523 nm, 546 nm green emissions and the 659 nm red emission are observed. With the increasing pump power, the intensity ratios of I523/I659, I546/I659 and I523/I546 increase gradually. The phenomenon is reasonably interpreted by theoretical analysis based on steady state rate equations. The emission cross section of the infrared emission at 1546 nm is larger (about 6.7 × 10− 21 cm2), which is suitable for making fiber amplifier. 相似文献
11.
12.
通过燃烧法制备了Yb3+-Tm3+共掺的Y2O3纳米粉体,并对样品在980 nm激光照射下的上转换发光特性进行了研究.实验发现,样品在可见光区域能够产生强烈的蓝色发光(476 nm和487 nm)和较弱的红色发光(约650 nm),而且同时观察到了两个紫外发光峰1I6→3H6 (~297 nm)和1
关键词:
2O3:Yb3+')" href="#">Y2O3:Yb3+
3+')" href="#">Tm3+
上转换光谱
敏化
紫外发光 相似文献
13.
The fluorescence property of xTbF3-BaF2-AlF3-GeO2+ySmF3 (x=0.01-40 mol%, y=0-5 wt%) glasses were investigated. The enhancement of Sm3+ fluorescence was recognized in the presence of Tb3+. Increasing Tb3+ content, the emission color changed from green to orange. When the intensity of fluorescence at 540 nm originated from Tb3+ is compared with that at 600 nm originated from Sm3+, the information about the concentration quenching of Tb3+ and Sm3+ was obtained. From these results, rare earth ions were dispersed identically in the glasses. After heating to 673 K or cooling to 77 K, the emission color of 20TbF3-20BaF2-10AlF3-50GeO2/mol%+0.05 wt% SmF3 glass was reversibly changed from orange to green. In addition, while the emission from 10TbF3-20BaF2-10AlF3-60GeO2+0.01 wt% SmF3 glass was green, its crystallized sample, prepared by annealing at 1073 K, exhibited an orange emission due to Sm3+ at room temperature. 相似文献
14.
We prepared Er3+ doped and Er3+/Yb3+ codoped Sb2O4 nanocrystals by the sol-gel method. The Raman, X-ray diffraction (XRD), transmission electron microscope (TEM), and photoluminescence spectra of the samples were studied. The phonon energy of the Sb2O4 nanocrystals is very low (the maximum value being 461 cm−1). The upconversion (UC) red emission of the Er3+/Yb3+ codoped sample is very strong at 975 nm laser diode excitation. The Sb2O4 nanocrystals will be a promising luminous material. 相似文献
15.
V.P. Solntsev A.P. YelisseyevT.B. Bekker A.E. KokhS. Yu. Stonoga A.V. DavydovA. Maillard 《Optics Communications》2012,285(24):5205-5209
Optical absorption and luminescence spectra of ytterbium and terbium codoped BaB2O4 (β-BBO and α-BBO) crystals grown in different conditions have been studied. Low-temperature absorption peaks were observed in all samples. Features related to rare earth ions were observed in absorption and luminescence spectra. Absorption and emission in the range 860-1000 nm are caused by 2F5/2↔2F7/2 transitions in Yb3+ ions. Emission peaks at 500, 550, 590 and 630 nm correspond to 5D4→7F6, 7F5, 7F4, and 7F3 transitions of Tb3+ ions, respectively. The probable reasons of variations in spectroscopic features related to Yb in BBO host are discussed. It has been shown that the replacement of Ва2+ by Yb3+ in the lattice of ВаВ2О4 results in the decrease in the symmetry of oxygen surrounding of Yb3+. 相似文献
16.
制备了高折射率Tm3+/Yb3+共掺杂铋碲酸盐玻璃,利用棱镜耦合法测量出玻璃在632.8和1550nm波长处的折射率分别为2.0365和1.9795. 对玻璃的吸收、荧光和红外透过光谱展开了测试与分析,根据Judd-Ofelt理论对吸收光谱进行拟合,求得Tm3+的振子强度参数Ωt(t=2,4,6)分别为3.90×10-20, 2.03×10-20和9.03×10-2
关键词:
3+/Yb3+共掺')" href="#">Tm3+/Yb3+共掺
铋碲酸盐玻璃
光谱参数
上转换荧光 相似文献
17.
The Er^3+/Yb^3+ co-doped TeO2-Nb2O5-Li2O glass is prepared by conventional melting method, and its upconversion spectra are measured. The intense green upconversion luminescence upon excitation with a 976 nm laser diode is observed with the naked eyes. The dependence of luminescence intensity on the ratio of Yb^3+/Er^3+ is discussed in detail, and the relationship between the ratio of green luminescence intensity to red luminescence intensity and the ratio of Yb^3+/Er^3+ is also studied, The luminescence intensity increases with the ratio of Yb^3+/Er^3+ increasing. The ratio of Yb^3+/Er^3+ plays a more important role than the concentration of Er^3+ in determining the upconversion luminescence intensity. The ratio of green luminescence intensity to red luminescence intensity reaches a maximum when ratio of Yb^3+/Er^3+ is 3. Thus the glass could be one of the potential candidates for LD pumping solid-state lasers. 相似文献
18.
通过固相反应法制备了Er3+/Yb3+共掺杂ZrO2-Al2O3粉末的样品,并对样品在980nm激光激发下的上转换发光特性进行了研究.从发射光谱可以发现,在可见光范围内有3个强的发光带,一个位于654nm附近的红光带和两个分别位于545nm、525nm附近的绿光带,分别对应于Er3+离子的以下辐射跃迁:4F9/2→4I15/2、4S3/2→4I15/2、 2H11/2→4I15/2.其中又以Er3+离子的4F9/2→4I15/2跃迁产生的红色荧光辐射最强.对其上转换发光机制进行了分析,发现这三个发光过程都是双光子过程.对样品粉末进行了XRD检测,发现ZrO2主要以立方相为主,并且计算得到了这种立方结构的晶格常数.Al2O3固溶于ZrO2中,Al3+嵌入ZrO2后产生氧空位,导致ZrO2晶体的对称性降低,这种结构变化更有利于提高上转换效率,即上转换发光强度增强.
关键词:
3+/Yb3+')" href="#">Er3+/Yb3+
上转换
2-Al2O3')" href="#">ZrO2-Al2O3
荧光
稀土 相似文献
19.
20.
Weihua Di Xiaoxia Zhao Zhaogang Nie Xiaojun Wang Shaozhe Lu Haifeng Zhao Xinguang Ren 《Journal of luminescence》2010,130(4):728-7292
CePO4:Tb nanorods were synthesized via a simple wet-chemical route. The as-synthesized CePO4:Tb nanorods present high photoluminescence efficiency due to an efficient energy transfer form Ce3+ to Tb3+. However, heat treatment at 150 °C in air leads to a significant decrease of photoluminescence. X-ray photoelectron spectroscopy and excitation spectra revealed the oxidation of Ce3+ to Ce4+ in the heat-treatment process, which should be responsible for significant photoluminescence degradation due to the breakage of Ce3+→Tb3+ energy transfer. This conclusion is further supported by atmosphere and size effects of photoluminescence of CePO4:Tb under the heat treatment. 相似文献