Structure-Dependent Spectroscopic Properties of Yb3+-Doped Phosphosilicate Glasses Modified by SiO2

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Ling Wang

2017-02-01

Full Text Available Yb3+-doped phosphate glasses containing different amounts of SiO2 were successfully synthesized by the conventional melt-quenching method. The influence mechanism of SiO2 on the structural and spectroscopic properties was investigated systematically using the micro-Raman technique. It was worth noting that the glass with 26.7 mol % SiO2 possessed the longest fluorescence lifetime (1.51 ms, the highest gain coefficient (1.10 ms·pm2, the maximum Stark splitting manifold of 2F7/2 level (781 cm−1, and the largest scalar crystal-field NJ and Yb3+ asymmetry degree. Micro-Raman spectra revealed that introducing SiO2 promoted the formation of P=O linkages, but broke the P=O linkages when the SiO2 content was greater than 26.7 mol %. Based on the previous 29Si MAS NMR experimental results, these findings further demonstrated that the formation of [SiO6] may significantly affect the formation of P=O linkages, and thus influences the spectroscopic properties of the glass. These results indicate that phosphosilicate glasses may have potential applications as a Yb3+-doped gain medium for solid-state lasers and optical fiber amplifiers.

Structure-Dependent Spectroscopic Properties of Yb3+-Doped Phosphosilicate Glasses Modified by SiO2

Science.gov (United States)

Wang, Ling; Zeng, Huidan; Yang, Bin; Ye, Feng; Chen, Jianding; Chen, Guorong; Smith, Andew T.; Sun, Luyi

2017-01-01

Yb3+-doped phosphate glasses containing different amounts of SiO2 were successfully synthesized by the conventional melt-quenching method. The influence mechanism of SiO2 on the structural and spectroscopic properties was investigated systematically using the micro-Raman technique. It was worth noting that the glass with 26.7 mol % SiO2 possessed the longest fluorescence lifetime (1.51 ms), the highest gain coefficient (1.10 ms·pm2), the maximum Stark splitting manifold of 2F7/2 level (781 cm−1), and the largest scalar crystal-field NJ and Yb3+ asymmetry degree. Micro-Raman spectra revealed that introducing SiO2 promoted the formation of P=O linkages, but broke the P=O linkages when the SiO2 content was greater than 26.7 mol %. Based on the previous 29Si MAS NMR experimental results, these findings further demonstrated that the formation of [SiO6] may significantly affect the formation of P=O linkages, and thus influences the spectroscopic properties of the glass. These results indicate that phosphosilicate glasses may have potential applications as a Yb3+-doped gain medium for solid-state lasers and optical fiber amplifiers. PMID:28772601

Optical properties of Mg2+, Yb3+, and Ho3+ tri-doped LiNbO3 crystals

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Dai, Li; Liu, Chun-Rui; Tan, Chao; Yan, Zhe-Hua; Xu, Yu-Heng

2017-04-01

A series of LiNbO3 crystals tri-doped with Mg{}2+, Yb{}3+, and Ho{}3+ are grown by the conventional Czochraski technique. The concentrations of Mg{}2+, Yb{}3+, and Ho{}3+ ions in Mg:Yb:Ho:LiNbO3 crystals are measured by using an inductively coupled plasma atomic emission spectrometry. The x-ray diffraction is proposed to determine the lattice constant and analyze the internal structure of the crystal. The light-induced scattering of Mg:Yb:Ho:LiNbO3 crystal is quantitatively described via the threshold effect of incident exposure energy flux. The exposure energy ({E}{{r}}) is calculated to discuss the optical damage resistance ability. The exposure energy of Mg(7 mol):Yb:Ho:LiNbO3 crystal is 709.17 J/cm2, approximately 425 times higher than that of the Mg(1 mol):Yb:Ho:LiNbO3 crystal in magnitude. The blue, red, and very intense green bands of Mg:Yb:Ho:LiNbO3 crystal are observed under the 980-nm laser excitation to evaluate the up-conversion emission properties. The dependence of the emission intensity on pumping power indicates that the up-conversion emission is a two-photon process. The up-conversion emission mechanism is discussed in detail. This study indicates that Mg:Yb:Ho:LiNbO3 crystal can be applied to the fabrication of new multifunctional photoluminescence devices. Project supported by the National Natural Science Foundation of China (Grant No. 51301055), the Youth Science Fund of Heilongjiang Province, China (Grant No. QC2015061), the Special Funds of Harbin Innovation Talents in Science and Technology Research, China (Grant No. 2015RQQXJ045 ), and the Science Funds for the Young Innovative Talents of Harbin University of Science and Technology, China (Grant No. 201501).

Enhanced Power Conversion Efficiency of Perovskite Solar Cells with an Up-Conversion Material of Er3+-Yb3+-Li+ Tri-doped TiO2.

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Zhang, Zhenlong; Qin, Jianqiang; Shi, Wenjia; Liu, Yanyan; Zhang, Yan; Liu, Yuefeng; Gao, Huiping; Mao, Yanli

2018-05-11

In this paper, Er 3+ -Yb 3+ -Li + tri-doped TiO 2 (UC-TiO 2 ) was prepared by an addition of Li + to Er 3+ -Yb 3+ co-doped TiO 2 . The UC-TiO 2 presented an enhanced up-conversion emission compared with Er 3+ -Yb 3+ co-doped TiO 2 . The UC-TiO 2 was applied to the perovskite solar cells. The power conversion efficiency (PCE) of the solar cells without UC-TiO 2 was 14.0%, while the PCE of the solar cells with UC-TiO 2 was increased to 16.5%, which presented an increase of 19%. The results suggested that UC-TiO 2 is an effective up-conversion material. And this study provided a route to expand the spectral absorption of perovskite solar cells from visible light to near-infrared using up-conversion materials.

Violet-green excitation for NIR luminescence of Yb3+ ions in Bi2O3-B2O3-SiO2-Ga2O3 glasses.

Science.gov (United States)

Li, Weiwei; Cheng, Jimeng; Zhao, Guoying; Chen, Wei; Hu, Lili; Guzik, Malgorzata; Boulon, Georges

2014-04-21

60Bi(2)O(3)-20B(2)O(3)-10SiO(2)-10Ga(2)O(3) glasses doped with 1-9 mol% Yb(2)O(3) were prepared and investigated mainly on their violet-green excitation for the typical NIR emission of Yb(3+), generally excited in the NIR. Two violet excitation bands at 365 nm and 405 nm are related to Yb(2+) and Bi(3+). 465 nm excitation band and 480 nm absorption band in the blue-green are assigned to Bi(0) metal nanoparticles/grains. Yb-content-dependence of the excitation and absorption means that Bi(0) is the reduced product of Bi(3+), but greatly competed by the redox reaction of Yb(2+) ↔ Yb(3+). It is proved that the violet-green excitations result in the NIR emission of Yb(3+). On the energy transfer, the virtual level of Yb(3+)-Yb(3+) as well as Bi(0) dimers probably plays an important role. An effective and controllable way is suggested to achieve nano-optical applications by Bi(0) metal nanoparticles/grains and Yb(3+).

Spectroscopic properties of Er3+ and Yb3+ co-doped glass ceramics containing SrF2 nanocrystals

International Nuclear Information System (INIS)

Qiao Xvsheng; Fan Xianping; Wang Minquan; Zhang Xianghua

2009-01-01

The spectroscopic properties of Er 3+ /Yb 3+ co-doped 50SiO 2 -10Al 2 O 3 -20ZnF 2 -20SrF 2 glass and glass ceramic containing SrF 2 nanocrystals were investigated. The formation of SrF 2 nanocrystals in the glass ceramic was confirmed by XRD. The oscillator strengths for several transitions of the Er 3+ ions in the glass ceramic have been obtained and the Judd-Ofelt parameters were then determined. The XRD result and Judd-Ofelt parameters suggested that Er 3+ and Yb 3+ ions had efficiently enriched in the SrF 2 nanocrystals in the glass ceramic. The lifetime of excited states has been used to reveal the surroundings of luminescent Er 3+ and Yb 3+ and energy transfer (ET) mechanism between Er 3+ and Yb 3+ . Much stronger upconversion luminescence and longer lifetime of the Er 3+ /Yb 3+ co-doped glass ceramic were observed in comparison with the Er 3+ /Yb 3+ co-doped glass, which could be ascribed to more efficient ET from Yb 3+ to Er 3+ due to the enrichment of Yb 3+ and Er 3+ and the shortening of the distance between lanthanide ions in the precipitated SrF 2 nanocrystals.

White phosphor using Yb3+-sensitized Er3+-and Tm3+-doped sol-gel derived lead-fluorosilicate transparent glass ceramic excited at 980 nm

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Tavares, M. C. P.; da Costa, E. B.; Bueno, L. A.; Gouveia-Neto, A. S.

2018-01-01

Generation of primary colors and white light through frequency upconversion using sol-gel derived 80SiO2:20PbF2 vitroceramic phosphors doped with Er3+, Er3+/Yb3+, Tm3+/Yb3+, and Er3+/Tm3+/Yb3+ excited at 980 nm is demonstrated. For Er3+ and Er3+/Yb3+ doped samples emissions were obtained in the blue (410 nm), green (530, and 550 nm) and red (670 nm) regions, corresponding to the 2H9/2 → 4I15/2,2H11/2 → 4I15/2, 4S3/2 → 4I152 and 4F9/2 → 4I15/2 transitions of Er3+, respectively. The codoping with Yb3+ ions altered the spectral profile of most of the emissions compared to the single doped samples, resulting in changes in the emitted color, in addition to a significant increase in the emission intensity. In Tm3+/Yb3+ co-doped samples visible emissions in the blue (480 nm), and red (650 nm), corresponding to transitions 1G4 → 3H6 and 1G4 → 3F4 of Tm3+, respectively, were obtained. The emission intensity around 480 nm overcome the red emission, and luminescence showed a predominantly blue tone. White light with CIE-1931 coordinates (0.36; 0.34) was produced by homogeneously mixing up powders of heat treated at 400 °C co-doped samples 5.0Er3+/5.0Yb3+ and 0.5Tm3+/2.5Yb3+ in the mass ratio of 13%, and 87%, respectively. The measured emission spectrum for a sample resulting from the mixture showed a profile with very good agreement with the spectrum found from the superimposition of the spectra of the co-doped samples.

Infrared to visible upconversion luminescence in Er3+/Yb3+ co-doped CeO2 inverse opal

International Nuclear Information System (INIS)

Yang, Zhengwen; Wu, Hangjun; Liao, Jiayan; Li, Wucai; Song, Zhiguo; Yang, Yong; Zhou, Dacheng; Wang, Rongfei; Qiu, Jianbei

2013-01-01

Highlights: • UC emission of Er 3+ was modified by introducing the structure of inverse opal. • Color tuning of CeO 2 :Yb, Er inverse opal was realized by inhibition of UC emission. • Two-photon excitation processes were observed in CeO 2 :Yb, Er inverse opal. -- Abstract: Infrared to visible upconversion luminescence has been investigated in Er 3+ /Yb 3+ co-doped CeO 2 inverse opal. Under the excitation of 980 nm diode lasers, visible emissions centered at 525, 547, 561, 660 and 680 nm are observed, which are assigned to the Er 3+ transitions of 2 H 11/2 → 4 I 15/2 (525 nm), 4 S 3/2 → 4 I 15/2 (547, 561 nm), 4 F 9/2 → 4 I 15/2 (660 and 680 nm), respectively. The effect of photonic band gap on the upconversion luminescence intensity was also obtained. Additionally, the upconversion luminescence mechanism was studied. The dependence of Er 3+ upconversion emission intensity on pump power reveals that it is a two-photon excitation process

Incorporation and conduction of proton in Sr-doped LaMO3 (M=Al, Sc, In, Yb, Y)

International Nuclear Information System (INIS)

Okuyama, Yuji; Kozai, Takeshi; Ikeda, Shohei; Matsuka, Maki; Sakai, Takaaki; Matsumoto, Hiroshige

2014-01-01

In order to clarify the effect of the B site species in ABO 3 perovskite oxides on the proton transport properties, the proton incorporation into a series of La 0.9 Sr 0.1 MO 3-δ , (M = Al, Sc, In, Yb, Y) was studied by measuring the electrical conductivity and electromotive forces of the gas concentration cells, and by a thermogravimetric analysis. The proton concentration and electrical conductivity increased in the order of the B site species, Al 0.9 Sr 0.1 AlO 3-δ showed an oxide ion conductivity, while La 0.9 Sr 0.1 YbO 3-δ and La 0.9 Sr 0.1 YO 3-δ exhibited a protonic conductivity in the temperature range of 573–1173 K. La 0.9 Sr 0.1 ScO 3-δ and La 0.9 Sr 0.1 InO 3-δ showed a protonic conductivity under 873 K, and a mixed proton and oxide ion conductivity at 1073 K

Infrared emissions in MgSrAl10O17:Er3+ phosphor co-doped with Yb3+/Ba2+/Ca2+ obtained by solution combustion route

International Nuclear Information System (INIS)

Singh, Vijay; Kumar Rai, Vineet; Venkatramu, V.; Chakradhar, R.P.S.; Hwan Kim, Sang

2013-01-01

An intense infrared emitting MgSrAl 10 O 17 :Er 3+ phosphor co-doped with Yb 3+ , Ba 2+ and Ca 2+ ions have been prepared by a solution combustion method. Phase purity of the derived compounds was confirmed by X-ray diffraction technique. The vibrational properties of MgSrAl 10 O 17 phosphor was studied by Fourier transform infrared spectroscopy. The broad and strong infrared emission of Er 3+ ions at around 1.53 μm was observed upon excitation at 980 nm. Effect of co-doping with the Yb 3+ , Ba 2+ and Ca 2+ ions on the infrared luminescence intensity of Er 3+ ions and the mechanism responsible for the variation in the infrared intensity have been discussed. The results indicate that these materials may be suitable for the optical telecommunication window and wavelength division multiplexing applications. - Highlights: ► The hexagonal phase of MgSrAl 10 O 17 could be obtained by the low temperature combustion method. ► The broad and strong infrared emission of Er 3+ ions at around 1.53 μm was observed. ► Effect of co-doping with the Yb 3+ , Ba 2+ and Ca 2+ ions on the infrared luminescence intensity of Er 3+ were reported.

Synthesis, microstructural characterization and optical properties of undoped, V and Sc doped ZnO thin films

International Nuclear Information System (INIS)

Amezaga-Madrid, P.; Antunez-Flores, W.; Ledezma-Sillas, J.E.; Murillo-Ramirez, J.G.; Solis-Canto, O.; Vega-Becerra, O.E.; Martinez-Sanchez, R.; Miki-Yoshida, M.

2011-01-01

Research highlights: → Undoped, V and Sc doped ZnO thin films by Aerosol Assisted Chemical Vapour Deposition. → Optimum substrate temperatures of 673 K and 623 K for Sc and V doped films. → Around one third of the dopants in solution were deposited into the films. → Crystallite and grain size decreased with the increase of dopant concentration. → Optical band gap increased from 3.29 to 3.32 eV for undoped to 7 Sc/Zn at. %. - Abstract: Many semiconductor oxides (ZnO, TiO 2 , SnO 2 ) when doped with a low percentage of non-magnetic (V, Sc) or magnetic 3d (Co, Mn, Ni, Fe) cation behave ferromagnetically. They have attracted a great deal of interest due to the integration of semiconducting and magnetic properties in a material. ZnO is one of the most promising materials to carry out these tasks in view of the fact that it is optically transparent and has n or p type conductivity. Here, we report the synthesis, microstructural characterization and optical properties of undoped, V and Sc doped zinc oxide thin films. ZnO based thin films with additions of V and Sc were deposited by the Aerosol Assisted Chemical Vapour Deposition method. V and Sc were incorporated separately in the precursor solution. The films were uniform, transparent and non-light scattering. The microstructure of the films was characterized by Grazing Incidence X-ray Diffraction, Scanning Electron Microscopy, and Scanning Probe Microscopy. Average grain size and surface rms roughness were estimated by the measurement of Atomic Force Microscopy. The microstructure of doped ZnO thin films depended on the type and amount of dopant material incorporated. The optical properties were determined from specular reflectance and transmittance spectra. Results were analyzed to determine the optical constant and band gap of the films. An increase in the optical band gap with the content of Sc dopant was obtained.

Enhancement of Dielectric Breakdown Strength and Energy Conversion Efficiency of Niobate Glass-Ceramics by Sc2O3 Doping

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Xiao, Shi; Xiu, Shaomei; Yang, Ke; Shen, Bo; Zhai, Jiwei

2018-01-01

Niobate glass-ceramics K2O-SrO-Nb2O5-B2O3-Al2O3-SiO2 (KSN-BAS) doped with different amounts of Sc2O3 have been prepared through a melt quenching/controlled crystallization method, and the influence of the Sc2O3 content on their phase composition, microstructure, dielectric performance, and charge-discharge properties investigated. X-ray powder diffraction results showed that the peak positions of the KSr2Nb5O15 phase shifted to higher angle and the glass-ceramic microstructures were significantly improved by Sc2O3 addition. Based on these results, 0.5 mol.% Sc2O3 doping was found to achieve remarkable enhancement in energy storage density, which reached 9.63 ± 0.39 J/cm3 at dielectric breakdown strength of 1450.38 ± 29.01 kV/cm with high conversion efficiency of ˜ 92.1%. For pulsed power applications, discharge speed of 17 ns and power density of 0.48 MW/cm3 were obtained in the glass-ceramic with 0.5 mol.% Sc2O3. These results could provide a new design strategy for high-performance dielectric capacitors.

Yb and Er co-doped Y2Ce2O7 nanoparticles: synthesis and ...

Indian Academy of Sciences (India)

much attention due to their potential applications in display .... Figure 1. XRD patterns of Yb3+ and Er3+ co-doped Y2Ce2O7 nanoparticles prepared for 4 h at different sintering .... vels relax to the ground 4I15/2 level (You et al 2012). For.

Ho3+/Yb3+ co-doped TeO2-BaF2-Y2O3 glasses for ∼1.2 μm laser applications

Science.gov (United States)

Wang, Shunbin; Li, Chengzhi; Yao, Chuanfei; Jia, Shijie; Jia, Zhixu; Qin, Guanshi; Qin, Weiping

2017-02-01

Intense ∼1.2 μm fluorescence is observed in Ho3+/Yb3+ co-doped TeO2-BaF2-Y2O3 glasses under 915 nm laser diode excitation. The 1.2 μm emission can be ascribed to the transition 5I6→5I8 of Ho3+. With the introducing of BaF2, the content of OH in the glasses drops markedly, and the 1.2 μm emission intensity increases gradually as increasing the concentration percentage of BaF2. Furthermore, microstructured fibers based on the TeO2-BaF2-Y2O3 glasses are fabricated by using a rod-in-tube method, and a relative positive gain of ∼9.42 dB at 1175.3 nm is obtained in a 5 cm long fiber.

Evaluation of TeO2 content on the optical and spectroscopic properties of Yb3 +-doped calcium borotellurite glasses

Science.gov (United States)

Lima, A. M. O.; Gomes, J. F.; Hegeto, F. L.; Medina, A. N.; Steimacher, A.; Barboza, M. J.

2018-03-01

This paper reports the synthesis and the characterization of Yb3 +-doped calcium borotellurite (CaBTeX) glasses with composition 10CaF2-(29.5 - 0.4x)CaO-(60 - 0.6x)B2O3-xTeO2-0.5Yb2O3 (x = 10, 16, 22, 31 and 54 mol%). The results of XRD confirm the amorphous character of all the samples. The density, molar volume, refractive index and electronic polarizability values show an increase with TeO2 content. Otherwise, the optical band gap energy shows a decrease with the increase of TeO2 content. The replacement of CaO and B2O3 by TeO2 changes the glass structure, which decreases the excited Yb3 +/cm3 and, consequently, the luminescence intensity. The temperature dependence of luminescence was studied for all the samples up to 420 K. The fluorescence lifetime does not change significantly due to TeO2 addition. In addition, absorption and emission cross section were calculated and present high values as compared to other tellurite and phosphate glasses.

Electrical and microstructural properties of Yb-doped CeO2

Directory of Open Access Journals (Sweden)

B. Matović

2014-06-01

Full Text Available Nanopowdered Ce1−xYbxO2−δ solid solutions (0 ≤ x ≤ 0.2 were synthesized by a self-propagating room temperature synthesis. XRD and SEM were used to study the properties of these materials as well as the Yb solubility in CeO2 lattice. Results showed that all the obtained powders were solid solutions with a fluorite-type crystal structure and with nanometric particle size. The average size of Ce1−xYbxO2−δ particles was approximately 3 nm. Electrochemical impedance spectroscopy for the sintered pellets depicted that it was possible to separate Rbulk and Rgb in the temperature interval of 550–800 °C. The activation energy for the bulk conduction was 1.03 eV and for grain boundary conduction was 1.14 eV. Grain boundary resistivity dominates over the other resistivities. These measurements confirmed that Yb3+-doped CeO2 material had a potential as electrolyte for intermediate-temperature solid oxide fuel cell applications.

Enhancing upconversion emission of Er, Yb co-doped highly transparent YF3 films by synergistic tuning nano-textured morphology and crystallinity

International Nuclear Information System (INIS)

Qu, Ming-Hao; Wang, Ru-Zhi; Chen, Yan; Zhang, Ying; Li, Kai-Yu; Zhou, Hua; Yan, Hui

2014-01-01

Highly transparent Er, Yb codoped YF 3 upconversion films were successfully prepared by electron beam deposition method. The effects of the substrate temperature on the morphology, crystallinity and emission characteristics of Er, Yb codoped YF 3 films were studied carefully. It was found that the morphology and crystallinity varied from smooth amorphous to root-intertwined polycrystalline structure with the substrate temperature increase. Besides, the emission characteristics of the films can be modulated by the synergy of their surface morphologies and crystallinities. Remarkably, a large enhancement of the upconversion emission, up to five decades while only an insignificant decrease of the optical transmittance (10% at most), was achieved by forming root-intertwined polycrystalline structures. These highly transparent upconversion films may have good potential for enhancing the conversion efficiency of wide band-gap solar cells. -- Highlights: • Er, Yb co-dopedYF 3 upconversion films have been successfully prepared. • The upconversion property can be modulated by morphology and crystallinity. • The upconversion transparent YF 3 films are promising for solar cells applications

Growth and continuous-wave laser operation of disordered crystals of Yb3+:NaLa(WO4)2 and Yb3+:NaLa(MoO4)2

Science.gov (United States)

Liu, J.; Cano-Torres, J. M.; Cascales, C.; Esteban-Betegón, F.; Serrano, M. D.; Volkov, V.; Zaldo, C.; Rico, M.; Griebner, U.; Petrov, V.

2005-03-01

Single crystals of disordered NaLa(WO4)2 and NaLa(MoO4)2 doped with Yb3+ are grown by the Czochralski method from the melt. Continuous-wave laser operation with Ti:sapphire laser pumping is demonstrated at room temperature without special cooling. Tunability from 1017 to 1057 nm and from 1015 to 1053 nm is achieved for Yb:NaLa(WO4)2 and Yb:NaLa(MoO4)2, respectively. A maximum output power of 205 mW is obtained with Yb:NaLa(WO4)2.

Structural, spectroscopic, and tunable laser properties of Yb3+ -doped NaGd(WO4)2

Science.gov (United States)

Cascales, C.; Serrano, M. D.; Esteban-Betegón, F.; Zaldo, C.; Peters, R.; Petermann, K.; Huber, G.; Ackermann, L.; Rytz, D.; Dupré, C.; Rico, M.; Liu, J.; Griebner, U.; Petrov, V.

2006-11-01

Single crystals of Yb3+ -doped NaGd(WO4)2 with up to 20mol% ytterbium content have been grown by the Czochralski technique in air or in N2+O2 atmosphere and cooled to room temperature at different rates (4-250°C/h) . Only the noncentrosymmetric tetragonal space group I4¯ accounts for all reflections observed in the single crystal x-ray diffraction analysis. The distortion of this symmetry with respect to the centrosymmetric tetragonal space group I41/a is much lower for crystals cooled at a fast rate. Na+ , Gd3+ , and Yb3+ ions share the two nonequivalent 2b and 2d sites of the I4¯ structure, but Yb3+ (and Gd3+ ) ions are found preferentially in the 2b site. Optical spectroscopy at low (5K) temperature provides additional evidence of the existence of these two sites contributing to the line broadening. The comparison with the F7/22(n) and F5/22(n') Stark energy levels calculated using the crystallographic Yb-O bond distances allows to correlate the experimental optical bands with the 2b and 2d sites. As a novel uniaxial laser host for Yb3+ , NaGd(WO4)2 is characterized also with respect to its transparency, band-edge, refractive indices, and main optical phonons. Continuous-wave Yb3+ -laser operation is studied at room temperature both under Ti:sapphire and diode laser pumping. A maximum slope efficiency of 77% with respect to the absorbed power is achieved for the π polarization by Ti:sapphire laser pumping in a three-mirror cavity with Brewster geometry. The emission is tunable in the 1014-1079nm spectral range with an intracavity Lyot filter. Passive mode locking of this laser produces 120fs long pulses at 1037.5nm with an average power of 360mW at ≈97MHz repetition rate. Using uncoated samples of Yb:NaGd(WO4)2 at normal incidence in simple two-mirror cavities, output powers as high as 1.45W and slope efficiencies as high as 51% are achieved with different diode laser pump sources.

CoO-doped MgO-Al2O3-SiO2-colored transparent glass-ceramics with high crystallinity

Science.gov (United States)

Tang, Wufu; Zhang, Qian; Luo, Zhiwei; Yu, Jingbo; Gao, Xianglong; Li, Yunxing; Lu, Anxian

2018-02-01

To obtain CoO-doped MgO-Al2O3-SiO2 (MAS)-colored transparent glass-ceramics with high crystallinity, the glass with the composition 21MgO-21Al2O3-54SiO2-4B2O3-0.2CoO (in mol %) was prepared by conventional melt quenching technique and subsequently thermal treated at several temperatures. The crystallization behavior of the glass, the precipitated crystalline phases and crystallinity were analyzed by X-ray diffraction (XRD). The microstructure of the glass-ceramics was characterized by field emission scanning electron microscopy (FSEM). The transmittance of glass-ceramic was measured by UV spectrophotometer. The results show that a large amount of α-cordierite (indianite) with nano-size was precipitated from the glass matrix after treatment at 1020 °C for 3 h. The crystallinity of the transparent glass-ceramic reached up to 97%. Meanwhile, the transmittance of the glass-ceramic was 74% at 400 nm with a complex absorption band from 450 nm to 700 nm. In addition, this colored transparent glass-ceramic possessed lower density (2.469 g/cm3), lower thermal expansion coefficient (1.822 × 10-6 /℃), higher Vickers hardness (9.1 GPa) and higher bending strength (198 MPa) than parent glass.

Density-functional study on the robust ferromagnetism in rare-earth element Yb-doped SnO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Zhang, Kai-Cheng, E-mail: kczhang@yeah.net [College of Mathematics and Physics, Bohai University, Jinzhou 121013 (China); Li, Yong-Feng [Key Laboratory of Integrated Exploitation of Bayan Obo Multi-Metal ResourcesInner Mongolia University of Science and Technology, Baotou 014010 (China); School of Mathematics, Physics and Biological Engineering, Inner Mongolia University of Science and Technology, Baotou 014010 (China); Liu, Yong [State Key Laboratory of Metastable Materials Science and Technology and College of Science, Yanshan University, Qinhuangdao, Hebei 066004 (China); Chi, Feng [College of Engineering, Bohai University, Jinzhou 121013 (China)

2014-06-01

So far, little has been known about the ferromagnetism induced by p–f hybridization. We investigate the magnetic properties of Yb-doped SnO{sub 2} by first-principles calculations. We find that the doped system favors the ferromagnetic state and a room-temperature ferromagnetism can be expected in it. The origin of ferromagnetism can be attributed to the p–f hybridization between Yb impurity and its surrounding oxygen atoms. The formation energy of defect complex is calculated and the magnetic mediation of intrinsic vacancies is studied. Our results reveal that the formation energy of the defect complex with Sn vacancy is about 7.3 eV lower in energy than that with oxygen vacancy. This means Sn vacancy is much easier to form than oxygen vacancy in the presence of Yb substitution. The ferromagnetism of the doped system is greatly enhanced in the presence of Sn vacancies. - Highlights: • Room-temperature ferromagnetism can be expected in Yb-doped SnO{sub 2}. • The origin of ferromagnetism can be attributed to the p–f hybridization between Yb and O atoms. • Oxygen vacancies are much hard to form and contribute little to the ferromagnetism. • Sn vacancies are easy to form under oxygen-rich condition and stabilize the ferromagnetism effectively.

Spectral and laser properties of Er3+/Yb3+/Ce3+ tri-doped Ca3NbGa3Si2O14 crystal at 1.55 µm

Science.gov (United States)

Gong, Guoliang; Chen, Yujin; Lin, Yanfu; Huang, Jianhua; Gong, Xinghong; Luo, Zundu; Huang, Yidong

2018-04-01

An Er3+/Yb3+/Ce3+ tri-doped Ca3NbGa3Si2O14 (CNGS) crystal was grown by the Czochralski method. Spectral properties of the crystal, including the polarized absorption and fluorescence spectra, the fluorescence decay, as well as the energy transfer efficiency from Yb3+ to Er3+ were investigated in detail. End-pumped by a 976 nm diode laser, a 1556 nm continuous-wave laser with a maximum output power of 202 mW and a slope efficiency of 11.4% was achieved in the Er,Yb,Ce:CNGS crystal. The results indicate the Er,Yb,Ce:CNGS crystal is a promising 1.55 µm laser gain medium.

Upconversion luminescence properties of Y2O3:Yb3+, Er3+ nanostructures

International Nuclear Information System (INIS)

De Gejihu; Qin Weiping; Zhang Jishen; Zhang Jishuang; Wang, Yan; Cao Chunyan; Cui Yang

2006-01-01

Cubic Y 2 O 3 nanostructures doped with Yb 3+ and Er 3+ ions were synthesized by a facile hydrothermal method. Three distinct shapes such as nanotubes, nanospheres and nanoflakes formed in the products by adjusting the pH value of reacting solution. Powder X-ray diffraction analyses indicate that all the three nanostructures are pure cubic phase, while electron microscopy measurements confirm the formation of different morphologies. These nanostructures exhibit strong visible upconversion luminescence under the excitation of a 978-nm diode laser. In Yb 3+ - and Er 3+ - codoped Y 2 O 3 nanocrystals, the relative intensity of green emission became stronger as the size and morphology of sample changed from tubes to flakes

Efficient conversion from UV light to near-IR emission in Yb{sup 3+}-doped triple-layered perovskite CaLaNb{sub 3}O{sub 10}

Energy Technology Data Exchange (ETDEWEB)

Lu, Yuting; Li, Yuze; Qin, Lin; Huang, Yanlin [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123 (China); Qin, Chuanxiang, E-mail: qinchuanxiang@suda.edu.cn [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123 (China); Tsuboi, Taiju [Jiangsu-Singapore Joint Research Center for Organic/Bio-Electronics & Information Displays and Institute of Advanced Materials (IAM), Nanjing Tech University, Nanjing 211816 (China); Huang, Wei, E-mail: wei-huang@njtech.edu.cn [Jiangsu-Singapore Joint Research Center for Organic/Bio-Electronics & Information Displays and Institute of Advanced Materials (IAM), Nanjing Tech University, Nanjing 211816 (China)

2015-04-15

Graphical abstract: CaRNb{sub 3}O{sub 10} is a self-activated oxide due to charge transfer transition in octahedral NbO{sub 6} groups. CaLaNb{sub 3}O{sub 10}:Yb{sup 3+} presents intense IR emission due to the cooperative energy transfer from host (NbO{sub 6}) to Yb{sup 3+} is responsible. It could be expected to be potentially applicable for enhancing photovoltaic conversion efficiency of Si-based solar cells. - Abstract: Yb{sup 3+}-doped triple-layered perovskite CaLaNb{sub 3}O{sub 10} micro-particles were synthesized via the solid-state reaction method. The crystal structure and morphology of the polycrystalline samples were investigated by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) measurements, respectively. The reflectance spectra, photoluminescence (PL) excitation and emission spectra, the decay curves, and the absolute quantum efficiency (QE) of the near-infrared (NIR) emission (910–1100 nm) were measured. Under excitation of UV light, Yb{sup 3+}-doped perovskite shows an intense NIR emission attributed to the {sup 2}F{sub 5/2} → {sup 2}F{sub 7/2} transitions of Yb{sup 3+} ions, which could match maximum spectral response of a Si-based solar cell. This is beneficial for its possible application in an enhancement of the photovoltaic conversion efficiency of solar energy utilization. The efficient energy transfer in Yb{sup 3+}-doped CaLaNb{sub 3}O{sub 10} from NbO{sub 6} groups into Yb{sup 3+} ions was confirmed by the spectra and fluorescent decay measurements. Cooperative energy transfer (CET) was supposed to be the NIR emission mechanism.

NIR to visible upconversion in Er3+/Yb3+ co-doped CaYAl3O7 phosphor obtained by solution combustion process

International Nuclear Information System (INIS)

Singh, Vijay; Rai, Vineet Kumar; Al-Shamery, Katharina; Nordmann, Joerg; Haase, Markus

2011-01-01

Using the combustion synthesis, CaYAl 3 O 7 :Er 3+ phosphor powders co-doped with Yb 3+ have been prepared at low temperatures (550 o 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 Er 3+ doped CaYAl 3 O 7 phosphor powder has been observed. The effect of co-doping with triply ionized ytterbium in the CaYAl 3 O 7 :Er 3+ phosphor has been studied and the process involved is discussed. - Highlights: → The green emitting up-conversion CaYAl 3 O 7 :Er 3+ phosphor powders co-doped with Yb 3+ have been prepared by easy combustion method. → The combustion method is a simple, energy saving, fast and economical viable process. → The luminescence intensity in the co-doped phosphor is enhanced by several times compared to that of the singly (Er 3+ ) doped phosphor.

Spin reorientation behavior in Yb doped YMnO3

International Nuclear Information System (INIS)

Sharma, Neetika; Das, A.

2014-01-01

RMnO 3 with smaller rare-earths ions (R = Ho to Lu and Y) crystallize in the non-centrosymmetric hexagonal space group P6 3 cm. The magnetic structure of RMnO 3 compounds with (R=Er,Yb.Lu) are described by irreducible representations (IR) Γ 2,4 and Γ 1,3 for those with higher ionic radii (R=Ho,Y,Y-Er). Of recent the magnetic structure of YMnO 3 has been found to be better described by Γ 3 + Γ 4 IR. YbMnO 3 is another hexagonal manganite, with almost similar transition temperature, and basically shares all the physical properties of YMnO 3 , except for the magnetic structure. The magnetic structure of YbMnO 3 can be explained by Γ 2 or Γ 4 . The non collinear nature of magnetic ordering in these compounds arises due to the frustration inherent in these compounds. In this study we have probed the effect of a magnetic ion (Yb) on the magnetic structure of these frustrated isostructural compounds

Activation of visible up-conversion luminescence in transparent and conducting ZnO:Er:Yb films by laser annealing

International Nuclear Information System (INIS)

Lluscà, M.; López-Vidrier, J.; Lauzurica, S.; Sánchez-Aniorte, M.I.; Antony, A.; Molpeceres, C.; Hernández, S.; Garrido, B.; Bertomeu, J.

2015-01-01

Transparent and conducting ZnO:Er:Yb thin films with visible up-conversion (660-nm emission under 980-nm excitation) were fabricated by RF magnetron sputtering. The as-deposited films were found to be transparent and conducting and the activation of the Er ions in these films to produce up-conversion luminescence was achieved by different post-deposition annealing treatments in air, vacuum or by laser annealing using a Nd:YVO 4 laser. The structural, electrical and optical properties and the up-conversion efficiency of these films were found to be strongly influenced by the annealing method, and a detailed study is reported in this paper. It has been demonstrated that, although the air annealing was the most efficient in terms of up-conversion, laser annealing was the only method capable of activating Er ions while preserving the electrical conductivity of the doped films. It has been shown that a minimum energy was needed in laser annealing to optically activate the rare earth ions in the ZnO host material to produce up-conversion. Up-converting and transparent conducting ZnO:Er:Yb films with an electrical resistivity of 5×10 −2 Ω cm and transparency ~80% in the visible wavelength range has been achieved by laser annealing. - Highlights: • Transparent and conducting ZnO:Er:Yb films were grown via magnetron sputtering. • Post-annealing ZnO:Er:Yb is needed to optically activate Er ions. • Visible up-conversion emission at 660 nm is observed under 980 nm excitation. • A transparent and conducting up-converter is achieved by laser annealing

Growth and continuous-wave laser operation of disordered crystals of Yb3+:NaLa(WO4)2 and Yb3+:NaLa(MoO4)2

International Nuclear Information System (INIS)

Liu, J.; Rico, M.; Griebner, U.; Petrov, V.; Cano-Torres, J.M.; Cascales, C.; Esteban-Betegon, F.; Serrano, M.D.; Volkov, V.; Zaldo, C.

2005-01-01

Single crystals of disordered NaLa(WO 4 ) 2 and NaLa(MoO 4 ) 2 doped with Yb 3+ are grown by the Czochralski method from the melt. Continuous-wave laser operation with Ti:sapphire laser pumping is demonstrated at room temperature without special cooling. Tunability from 1017 to 1057 nm and from 1015 to 1053 nm is achieved for Yb:NaLa(WO 4 ) 2 and Yb:NaLa(MoO 4 ) 2 , respectively. A maximum output power of 205 mW is obtained with Yb:NaLa(WO 4 ) 2 . (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Effects of Al2O3 and/or CaO on properties of yttria stabilized zirconia electrolyte doped with multi-elements

International Nuclear Information System (INIS)

Lv Zhengang; Guo Ruisong; Yao Pei; Dai Fengying

2007-01-01

Yttria stabilized zirconia (YSZ) has a high oxide ion conductivity at high temperatures. Some rare earth elements (e.g., Yb, Sc, Dy) with similar cation radii to Zr 4+ can dissolve into ZrO 2 , increasing its vacancy concentration and crystal lattice distortion, and therefore enhancing its conductivity and lowering the activation energy. It is expected this material could be used as intermediate temperature electrolyte. In the present work, YSZ electrolyte materials doped by multi-elements (Sc 2 O 3 or Dy 2 O 3 and Yb 2 O 3 ) were prepared by high temperature solid-state method. The high temperature conductivity was improved obviously, reaching 0.18 S/cm at 1000 deg. C, but the density and mechanical properties of sintered materials were not sufficiently high. It is found that sinterability and mechanical properties could be improved by inclusion of a small amount of Al 2 O 3 and/or CaO into the multi-elements doped YSZ materials and our results proved it. The results showed density and bending strength of sintered bodies were enhanced by Al 2 O 3 addition by 4.6% and 30%, respectively, while the conductivity did not degrade remarkably. But the degradation in bending strength and conductivity resulting from the CaO addition happened due to the second phase formed at the grain boundary. XRD patterns showed that all samples had cubic fluorite structure and crystalline lattice parameter was increased. SEM photographs obviously revealed the grain growth for the samples with CaO inclusion

Luminescent and scintillation properties of Sc3+and La3+doped Y2SiO5 powders and single crystalline films

International Nuclear Information System (INIS)

Zorenko, Yu.; Gorbenko, V.; Zorenko, T.; Voznyak, T.; Voloshynovskii, A.; Vistovskiy, V.; Paprocki, K.; Mosińska, L.; Bilski, P.; Twardak, A.; Fedorov, A.; Nikl, M.; Mares, J.A.

2016-01-01

The paper is dedicated to the investigation of the luminescence of Sc 3+ and La 3+ isoelectronic impurities in Y 2 SiO 5 (YSO) single crystalline films (SCF), grown by the liquid phase epitaxy (LPE) method, and in the powder analogs of these compounds prepared using the ceramic technology. The Sc 3+ and La 3+ dopants replacing the Y 3+ cations in Y1and Y2 positions of YSO host introduce the strong complex emission bands in the UV range peaked at 330 and 345 nm, respectively. The Sc 3+ and La 3+ dopant in YSO matrix yields also the strong TSL peaks at 400 and 405 K related to the ScY and ScLa centers formation, respectively. The luminescence and scintillation properties of YSO SCFs doped with Sc 3+ and La 3+ ions and co-doped with Ce 3+ ions on the trace impurity level have been also studied in our work. We have found that the light yield (LY) of these YSO:Sc and YSO:La SCFs can reach 50–65% of LY in reference YSO:Ce SCF due to strong quenching influence of Pb 2+ ions. Finally, the potential of Sc 3+ and La 3+ doped SCF of orthosilicates for creation of heavy scintillation screens, emitting in the UV range, is discussed.

Yb:Lu{sub 2}O{sub 3} hydrothermally-grown single-crystal and ceramic absorption spectra obtained between 298 and 80 K

Energy Technology Data Exchange (ETDEWEB)

Moore, Cheryl A. [Snake Creek Lasers LLC, 26741 State Route 267, Friendsville, PA 18818 (United States); Department of Chemistry and Center for Optical Materials Science and Engineering Technologies, Clemson University, Clemson, SC 29634-0973 (United States); Brown, David C., E-mail: dbrown@snakecreeklasers.com [Snake Creek Lasers LLC, 26741 State Route 267, Friendsville, PA 18818 (United States); Sanjeewa, Liurukara D.; McMillen, Colin D.; Kolis, Joseph W. [Department of Chemistry and Center for Optical Materials Science and Engineering Technologies, Clemson University, Clemson, SC 29634-0973 (United States)

2016-06-15

The hydrothermal growth, doping, and low temperature spectral characterization of Yb doped Lu{sub 2}O{sub 3} was investigated. The absorption of the lutetia-based sesquioxide laser material Yb:Lu{sub 2}O{sub 3} at temperatures of 80, 150, 200, 250, and 298 K, in the wavelength range of 850–1100 nm are reported. Data for both single crystal and ceramic Yb:Lu{sub 2}O{sub 3} were obtained. The resulting absorption cross-section data will enable the further evaluation of Yb:Lu{sub 2}O{sub 3} as a very promising high power cryogenic laser material.

Investigation of upconversion luminescence in antimony–germanate double-clad two cores optical fiber co-doped with Yb{sup 3+}/Tm{sup 3+} and Yb{sup 3+}/Ho{sup 3+} ions

Energy Technology Data Exchange (ETDEWEB)

Zmojda, J.; Kochanowicz, M.; Miluski, P.; Dorosz, J. [Bialystok University of Technology, Wiejska 45 Street, 15-351 Bialystok (Poland); Pisarska, J.; Pisarski, W.A. [Institute of Chemistry, University of Silesia, Szkolna 9, 40-007 Katowice (Poland); Dorosz, D., E-mail: d.dorosz@pb.edu.pl [Bialystok University of Technology, Wiejska 45 Street, 15-351 Bialystok (Poland)

2016-02-15

In the paper double-clad optical fiber with two off-set cores co-doped with 1Yb{sub 2}O{sub 3}–0.1Tm{sub 2}O{sub 3} and 1Yb{sub 2}O{sub 3}–0.5Ho{sub 2}O{sub 3} has been investigated. Antimony–germanate glass was melted as a matrix for active cores. The concentration of lanthanides and their ratio have been optimized to achieve maximum upconversion emission intensity at 478 nm ({sup 1}G{sub 4}→{sup 3}H{sub 6}) and 650 nm ({sup 1}G{sub 4}→{sup 3}F{sub 4}) in glasses doped with Tm{sup 3+} ions and 545 nm and 655 nm, corresponding to the {sup 5}F{sub 5}→{sup 5}I{sub 8} and {sup 5}F{sub 4}→{sup 5}I{sub 8} transitions in holmium ions. The energy transfer efficiency in glasses used as optical fiber cores was η{sub Tm}=56% (0.1 mol% Tm{sub 2}O{sub 3}) and η{sub Ho}=85% (0.5 mol% Ho{sub 2}O{sub 3}), respectively. As a result of excitation of the fabricated optical fiber (λ{sub exc}=976 nm), a UC luminescence spectra was obtained. Superposition of three emission bands at the wavelengths of 481 nm (Tm{sup 3+}: blue), 545 nm (Ho{sup 3+}:green) and 665 nm (Tm{sup 3+}, Ho{sup 3+}: red) from two separated cores was measured. Influence of fiber length and excitation power on the color coordinates (CIE-1931) have been also investigated. - Highlights: • Antimony-germanate glasses co-doped with Yb{sup 3+}/Tm{sup 3+} and Yb{sup 3+}/Ho{sup 3+} were presented. • UC luminescence in double-clad, two off-set core co-doped with Yb{sup 3+}/Tm{sup 3+} and Yb{sup 3+}/Ho{sup 3+} optical fiber was presented. • The chromatic coordinates shift in the blue region at CIE scheme as a function of pump power and length of optical fiber was observed.

Optical properties of ytterbium-doped yttrium oxide ceramics

Energy Technology Data Exchange (ETDEWEB)

Solomonov, V.I.; Maksimov, R.N. [Institute of Electrophysics UrB RAS, Amundsena 106, 620016 Ekaterinburg (Russian Federation); Ural Federal University Named After the First President of Russia B.N. Yeltsin, Mira 19, 620002 Ekaterinburg (Russian Federation); Osipov, V.V.; Shitov, V.A.; Lipchak, A.I. [Institute of Electrophysics UrB RAS, Amundsena 106, 620016 Ekaterinburg (Russian Federation)

2017-05-15

Ytterbium-doped yttrium oxide (Yb:Y{sub 2}O{sub 3}) transparent ceramics with different sintering additives (Lu{sub 2}O{sub 3}, Sc{sub 2}O{sub 3}, CeO{sub 2}, ZrO{sub 2}, or HfO{sub 2}) were fabricated using nanopowders produced by laser ablation. Transmission and photoluminescence spectra of the obtained ceramics were investigated at room temperature. Highest in-line transmittance was over 80% at the wavelength of 1060 nm for 2 mm thick Yb:Y{sub 2}O{sub 3} ceramics with zirconium and hafnium. Divalent Yb ions with the ground state electron configuration 4f{sup 13}6s were revealed. The absorption and emission bands caused by s <-> s transitions of these ions were observed in the IR spectral range of Yb{sup 3+} ions. The superposition of both Yb{sup 3+} and Yb{sup 2+} emission bands leads to an effective broadening of the whole luminescence band. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Investigation of thermal stability and spectroscopic properties in Er3+/Yb3+-codoped TeO2-Li2O-B2O3-GeO2 glasses.

Science.gov (United States)

Nie, Qiu-Hua; Gao, Yuan; Xu, Tie-Feng; Shen, Xiang

2005-06-01

The new Er3+/Yb3+ co-doped 70TeO2-5Li2O-(25-x)B2O3-xGeO2 (x = 0, 5, 10, 15 fand 20 mol.%) glasses were prepared. The thermal stability, absorption spectra, emission spectra and lifetime of the 4I(13/2) level of Er3+ ions were measured and studied. The FT-IR spectra were carried out in order to investigate the structure of local arrangements in glasses. It is found that the thermal stability, absorption cross-section of Yb3+, emission intensity and lifetime of the 4I(13/2) level of Er3+ increase with increasing GeO2 content in the glass composition, while the fluorescence width at half maximum (FWHM) at 1.5 um of Er3+ is about 70 nm. The obtained data suggest that this system glass can be used as a candidate host material for potential broadband optical amplifiers.

Persistent luminescence in both first and second biological windows in ZnGa2O4:Cr3+,Yb3+ glass ceramics

Science.gov (United States)

Castaing, V.; Sontakke, A. D.; Xu, J.; Fernández-Carrión, A. J.; Allix, M.; Tanabe, S.; Viana, B.

2018-02-01

ZnGa2O4:Cr3+ is an optical material well known for its deep red persistent luminescence properties which are centered in the first biological window. In this work, Yb3+, Cr3+ co-doped zinc gallate oxide has been prepared in the form of glass-ceramics. The studied samples have been elaborated via conventional melt quenching process leading to nanometer scale phase separated glass which was subsequently crystallized to obtain nanocrystals embedded in a transparent glass matrix. In these as-prepared ZnGa2O4:Cr3+,Yb3+ glass-ceramics, regular Cr3+ emission (at around 695 nm) as well as Yb3+ emission (between 950 and 1100 nm) is observed. Several photoluminescence emission and excitation experiments have been recorded in order clarify (i) the simultaneous emission of these cations in different optical windows and (ii) the energy transfer process between these two emitting centers. Further studies proved that Yb3+ is not only active in photoluminescence but also in persistent luminescence, leading to a material demonstrating persistent luminescence properties in both first and second biological windows (650-950 and 1000-1350 nm respectively). Thermoluminescence experiments have been carried out on these materials in order to gain deeper information about the persistent luminescence process.

Synthesis of Sc{sub 2}O{sub 3} powders for preparation of transparent ceramics; Synthese de poudres de Sc{sub 2}O{sub 3} destinees a l'elaboration d'une ceramique transparente

Energy Technology Data Exchange (ETDEWEB)

Bravo, A.C.; Longuet, L.; Autissier, D. [CEA Centre d' Etudes du Ripault, 37 - Tours (France); Baumard, J.F. [Laboratoire Science des Procedes Ceramiques et de Traitements de Surfaces, SPCTS, UMR CNRS 6638, 87 - Limoges (France)

2007-07-01

Different precursors have been prepared by precipitation from scandium nitrates salts using ammonium hydrogeno-carbonate as precipitating agent. The influence of the precipitation technique, of the preparation temperature and of the 'precipitating agent/Sc{sup 3+}' molar ratio on the characteristics (nature, grain size...) of the synthesized precursors has been observed. A heat treatment at 700 C of these precursors has allowed to obtain thin and homogeneous Sc{sub 2}O{sub 3} powders well adapted for transparent ceramics preparation. (O.M.)

Luminescence property and emission enhancement of YbAlO3:Mn4+ red phosphor by Mg2+ or Li+ ions

Science.gov (United States)

Cao, Renping; Luo, Wenjie; Xu, Haidong; Luo, Zhiyang; Hu, Qianglin; Fu, Ting; Peng, Dedong

2016-03-01

YbAlO3:Mn4+, YbAlO3:Mn4+, Li+, and YbAlO3:Mn4+, Mg2+ phosphors are synthesized by high temperature solid-state reaction method in air. Their crystal structures and luminescence properties are investigated. Photoluminescence excitation (PLE) spectrum monitored at 677 nm contains broad PLE band with three PLE peaks located at ∼318, 395, and 470 nm within the range 220-600 nm. Emission spectra with excitation 318 and 470 nm exhibit three emission band peaks located at ∼645, 677, and 700 nm in the range of 610-800 nm and their corresponding chromaticity coordinates are about (x = 0.6942, y = 0.3057). The possible luminous mechanism of Mn4+ ion is analyzed by the simple energy level diagram of Mn4+ ion. The optimum Mn4+-doped concentration in YbAlO3:Mn4+ phosphor is about 0.4 mol% and the luminescence lifetime of YbAlO3:0.4%Mn4+ phosphor is ∼0.59 ms. Emission intensity of YbAlO3:0.4%Mn4+ phosphor can be enhanced ∼6 times after Mg2+ ion is co-doped and it is ∼2 times when Li+ ion is co-doped. The content in the paper is useful to research new Mn4+-doped luminescence materials and improve luminescence property of other Mn4+-doped phosphors.

Comparative study of Tm-doped and Tm-Sc co-doped Lu3Al5O12 scintillator

International Nuclear Information System (INIS)

Sugiyama, Makoto; Yanagida, Takayuki; Fujimoto, Yutaka

2014-01-01

The crystals of Tm doped and Tm-Sc co-doped Lu 3 Al 5 O 12 (LuAG) grown by the floating zone (FZ) method were examined for their optical and scintillation properties. In transmittance spectra, strong absorption lines due to Tm 3+ 4f–4f transitions were observed. X-ray excited radioluminescence spectra were measured and broad and sharp emission peaks were detected. The former one was attributed to Sc 3+ and the latter one was due to Tm 3+ 4f–4f transitions. Scintillation yield enhancement due to Sc co-doping was observed by means of 137 Cs pulse height spectra. Scintillation decay times were several tens of μs under pulse X-ray excitation. - Highlights: • LuAG:Tm and LuAG:Tm, Sc single crystals have been grown by the FZ method. • Tm 3+ 4f–4f absorption has been observed in transmittance spectra. • Scintillation yield of Tm-doped LuAG has been enhanced by Sc co-doping

Yb-doped aluminophosphosilicate ternary fiber with high efficiency and excellent laser stability

Science.gov (United States)

Li, Yuwei; Peng, Kun; Zhan, Huan; Liu, Shuang; Ni, Li; Wang, Yuying; Yu, Juan; Wang, Xiaolong; Wang, Jianjun; Jing, Feng; Lin, Aoxiang

2018-03-01

By using chelate precursor doping technique and traditional modified chemical vapor deposition system, we fabricated Yb-doped aluminophosphosilicate (Al2O3-P2O5-SiO2, ternary Yb-APS) large-mode-area fiber and reported on its laser performance. The fiber preform was doped with Al, P and Yb with concentration of ∼8000 ppm, ∼1700 ppm and ∼400 ppm in molar percent, respectively. Tested with master oscillator power amplifier system, the home-made Yb-APS fiber was found to present 1.02 kW at 1061.1 nm with a high slope efficiency of 81.2% and excellent laser stability with power fluctuation less than ±1.1% for over 10 h. Compared with Yb-doped aluminosilicate (Al2O3-SiO2, binary Yb-AS) fiber, the introduction of P2O5 effectively suppressed photodarkening effect even the P/Al ratio is much less than 1, indicating that Yb-APS fiber is a better candidate for high power fiber lasers.

Fabrication of Y{sub 2}Ti{sub 2}O{sub 7}:Yb{sup 3+},Ho{sup 3+} nanoparticles by a gel-combustion approach and upconverting luminescent properties

Energy Technology Data Exchange (ETDEWEB)

Chen, Zhongsheng, E-mail: zhshcheng@ecit.cn [State Key Laboratory Breeding Base of Nuclear Resources and Environment, East China Institute of Technology, Nanchang, Jiangxi 330013 (China); Wang, Min; Wang, Haiqing; Le, Zhanggao; Huang, Guolin; Zou, Lixia; Liu, Zhirong [State Key Laboratory Breeding Base of Nuclear Resources and Environment, East China Institute of Technology, Nanchang, Jiangxi 330013 (China); Wang, Dianyuan; Wang, Qingkai [College of Science, Jiujiang University, Jiujiang, Jiangxi 332005 (China); Gong, Weiping [Electronic Science Department, Huizhou University, Huizhou, Guangdong 516001 (China)

2014-09-01

Highlights: • Co-doped (Y{sub 0.99−x}Ho{sub 0.01}Yb{sub x}){sub 2}Ti{sub 2}O{sub 7} nanophosphors were fabricated by gel-combustion method. • The effect of calcination and Yb{sup 3+} doping on upconverting spectra of nanophosphors was studied. • The dependence of upconverting intensity on the excitation power was examined. - Abstract: Yb{sup 3+}, Ho{sup 3+} co-doped pyrochlore-structured (Y{sub 0.99−x}Ho{sub 0.01}Yb{sub x}){sub 2}Ti{sub 2}O{sub 7} (x = 0, 2.5, 5.0, 7.5, 10.0 and 12.5 mol%) nanoparticles (NPs) were successfully fabricated via a gel-combustion approach. The products as-obtained were characterized by various techniques, i.e. X-ray diffraction, transmission electron microscope, Fourier transformed infrared spectra and upconverting spectra. The results indicate that the bright green (∼540 nm) and red (∼660 nm) emissions are observed in Y{sub 2}Ti{sub 2}O{sub 7}:Ho{sup 3+},Yb{sup 3+} NPs under the 980 nm excitation, which is ascribed to the radiative transitions ({sup 5}F{sub 4},{sup 5}S{sub 2}) → {sup 5}I{sub 8} and {sup 5}F{sub 5} → {sup 5}I{sub 8} of Ho{sup 3+} ions, respectively. It is also found that the calcining temperature and Yb{sup 3+} ion doping level have a great influence on the upconverting spectra of (Y{sub 0.99−x}Ho{sub 0.01}Yb{sub x}){sub 2}Ti{sub 2}O{sub 7} NPs. The emission intensities increase initially and then fall down from 800 to 1000 °C. The optimum doping level of Yb{sup 3+} ions is 7.5 mol%, and the intensity of upconverting emissions for (Y{sub 0.915}Ho{sub 0.01}Yb{sub 0.075}){sub 2}Ti{sub 2}O{sub 7} NPs is enhanced by the fold of 32 compared to the Yb{sup 3+}-free samples. The dependence of upconverting intensity on the excitation power reveals the contribution of two photons to both the green and red upconverting process under lower excitation power, and the possible upconverting mechanisms have been proposed accordingly.

Characterizations of Pr-doped Yb3Al5O12 single crystals for scintillator applications

Science.gov (United States)

Yoshida, Yasuki; Shinozaki, Kenji; Igashira, Takuya; Kawano, Naoki; Okada, Go; Kawaguchi, Noriaki; Yanagida, Takayuki

2018-04-01

Yb3Al5O12 (YbAG) single crystals doped with different concentrations of Pr were synthesized by the Floating Zone (FZ) method. Then, we evaluated their basic optical and scintillation properties. All the samples showed photoluminescence (PL) with two emission bands appeared approximately 300-500 nm and 550-600 nm due to the charge transfer luminescence of Yb3+ and intrinsic luminescence of the garnet structure, respectively. A PL decay profile of each sample was approximated by a sum of two exponential decay functions, and the obtained decay times were 1 ns and 3-4 ns. In the scintillation spectra, we observed emission peaks in the ranges from 300 to 400 nm and from 450 to 550 nm for all the samples. The origins of these emissions were attributed to charge transfer luminescence of Yb3+ and intrinsic luminescence of the garnet structure, respectively. The scintillation decay times became longer with increasing the Pr concentrations. Among the present samples, the 0.1% Pr-doped sample showed the lowest scintillation afterglow level. In addition, pulse height spectrum of 5.5 MeV α-rays was demonstrated using the Pr-doped YbAG, and we confirmed that all the samples showed a full energy deposited peak. Above all, the 0.1% Pr-doped sample showed the highest light yield with a value of 14 ph/MeV under α-rays excitation.

Dependence of upconversion emission intensity on Yb3+ concentration in Er3+/Yb3+ co-doped flake shaped Y2(MoO4)3 phosphors

International Nuclear Information System (INIS)

Lu Weili; Cheng Lihong; Zhong Haiyang; Sun Jiashi; Wan Jing; Tian Yue; Chen Baojiu

2010-01-01

Yttrium molybdate phosphors with fixed Er 3+ and various Yb 3+ concentrations were synthesized via a co-precipitation method. The crystal structure and the morphology of the phosphor were characterized by means of x-ray diffraction and field-emission scanning electron microscopy. Under 980 nm excitation, red and green upconversion emissions centred at 660, 553 and 530 nm were observed. Quantitative analyses on the dependence of upconversion emission intensity on the working current of a laser diode (LD) indicated that two-photon processes are responsible for both red and green upconversion emissions in both cases of low and high Yb 3+ concentrations. The relationship between the emission intensity ratio of 2 H 11/2 → 4 I 15/2 to 4 S 3/2 → 4 I 15/2 and the working current of the LD was studied for the samples doped with low and high Yb 3+ concentrations. Finally, a set of rate equations was established based on the possible upconversion mechanism, and an empirical formula was proposed to describe the Yb 3+ concentration dependence of upconversion emission intensity; the empirical formula fits well with the experimental data.

Up-conversion luminescence of Er3+/Yb3+/Nd3+-codoped tellurite glasses

International Nuclear Information System (INIS)

Lu Longjun; Nie Qiuhua; Xu Tiefeng; Dai Shixun; Shen Xiang; Zhang Xianghua

2007-01-01

Up-conversion luminescence and energy transfer (ET) processes in Nd 3+ -Yb 3+ -Er 3+ triply doped TeO 2 -ZnO-Na 2 O glasses have been studied under 800 nm excitation. Intense green up-conversion emissions around 549 nm, which can be attributed to the Er 3+ : 4 S 3/2 →4 I 15/2 transition, are observed in triply doped samples. In contrast, the green emissions are hardly observed in Er 3+ singly doped and Er 3+ -Yb 3+ codoped samples under the same condition. Up-conversion luminescence intensity exhibits dependence of Yb 2 O 3 -concentration and Nd 2 O 3 -concentration. Up-conversion mechanism in the triply doped glasses under 800 nm pump is discussed by analyzing the ET among Nd 3+ , Yb 3+ and Er 3+ . And a possible up-conversion mechanism based on sequential ET from Nd 3+ to Er 3+ through Yb 3+ is proposed for green and red up-conversion emission processes

Conversion and quantum efficiency from ultraviolet light to near infrared emission in Yb{sup 3+}-doped pyrovanadates MZnV{sub 2}O{sub 7} (M = Ca, Sr, Ba)

Energy Technology Data Exchange (ETDEWEB)

Guan, Ying; Huang, Yanlin [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123 (China); Tsuboi, Taiju; Huang, Wei [Jiangsu-Singapore Joint Research Center for Organic/Bio-Electronics and Information Displays and Institute of Advanced Materials, Nanjing Tech University, Nanjing 211816 (China); Chen, Cuili; Cai, Peiqing [Department of Physics and Interdisciplinary Program of Biomedical, Mechanical and Electrical Engineering, Pukyong National University, Busan 608-737 (Korea, Republic of); Seo, Hyo Jin, E-mail: hjseo@pknu.ac.kr [Department of Physics and Interdisciplinary Program of Biomedical, Mechanical and Electrical Engineering, Pukyong National University, Busan 608-737 (Korea, Republic of)

2014-12-15

Highlights: • Efficient convertors of Yb{sup 3+} doped pyrovanadates are prepared and characterized. • Broadband down-conversion from ultraviolet into near-infrared is realized. • High quantum efficiency of 18.5% can be reached. • Energy transfer from VO{sub 4} groups to Yb{sup 3+} ions is demonstrated on the base of the crystal structure. - Abstract: Yb{sup 3+}-doped CaZnV{sub 2}O{sub 7}, SrZnV{sub 2}O{sub 7} and BaZnV{sub 2}O{sub 7} were synthesized via the solid-state reaction. The polycrystalline samples were investigated by XRD and SEM measurements. The reflectance spectra, photoluminescence (PL) excitation and emission spectra, the absolute quantum efficiency (QE) of the IR emission (900–1100 nm) were measured. The efficient conversion from ultraviolet (UV) light to near-infrared (NIR) emission has been demonstrated in the Yb{sup 3+}-doped pyrovanadates by the broadband down conversion from VO{sub 4}{sup 3−} to Yb{sup 3+} ions. Under UV light excitation, an intense NIR emission around 1000 nm ascribed to the {sup 2}F{sub 5/2} → {sup 2}F{sub 7/2} transition of Yb{sup 3+} ions has been observed, which just corresponds to the spectral response of Si solar cells. The NIR emission efficiency is observed to depend on the lattice of pyrovanadate. The mechanism of the NIR emission ascribed to energy transfer is discussed by taking into account the experimental results and the crystal structures.

Spectral properties and laser performances of Yb3+:LaCa4O(BO3)3 crystal with high concentration doping

International Nuclear Information System (INIS)

Ji, Yuexia; Cao, Jiafeng; Xu, Jinlong; You, Zhenyu; Zhu, Zhaojie; Li, Jianfu; Wang, Yan; Tu, Chaoyang

2013-01-01

Highlights: •Yb 3+ :LaCa 4 O(BO 3 ) 3 single crystal was grown with high concentration doping. •Laser potentiality was evaluated based on the spectral and laser parameters. •Continuous wave laser operation was realized. •An output power of 0.77 W and a slope efficiency of 15.71% at 1077 nm were obtained. •The spectra and laser properties of Yb 3+ :LaCa 4 O(BO 3 ) 3 crystal were firstly reported. -- Abstract: High concentration of 15 at.% Yb 3+ doped LaCa 4 O(BO 3 ) 3 (LaCOB) crystal was grown by Czochralski technique. The absorption cross section was conclulated to be 0.63 × 10 −20 cm 2 at 977 nm and the emission cross section to be 0.39 × 10 −20 cm 2 at 1030 nm, with the FWHM of 6.15 and 33 nm respectively. Laser potentiality was evaluated based on the gain cross section σ g , the minimum inversion fraction β min and the minimum pump intensity I min , which were calculated to be 0.18 × 10 −20 cm 2 , 0.05 and 0.47 kw/cm 2 , respectively. Continuous wave laser operation was realized with an output power of 0.77 W and a slope efficiency of 15.71%. The laser emitted around 1077 nm. The radiation trapping and continuous pump mode are contributed to the lasing wavelength for present crystal

Hydrothermal synthesis of superparamagnetic and red luminescent bifunctional Fe{sub 3}O{sub 4}@Mn{sup 2+}-doped NaYF{sub 4}:Yb/Er core@shell monodisperse nanoparticles and their subsequent ligand exchange in water

Energy Technology Data Exchange (ETDEWEB)

Qin, Zhenli; Du, Sinan; Luo, Yang; Liao, Zhijian; Zuo, Fang, E-mail: polymerzf@swun.cn; Luo, Jianbin; Liu, Dong

2016-08-15

Graphical abstract: An efficient hydrothermal method was used to fabricate the superparamagnetic and red luminescent bifunctional Fe{sub 3}O{sub 4}@Mn{sup 2(*)+}-doped NaYF{sub 4}:Yb/Er nanoparticles (NPs) with core@shell structures through a seed-growth procedure. Then using PEG phosphate ligand to displace oleate from the as-synthesized NPs, hydrophilic Fe{sub 3}O{sub 4}@Mn{sup 2+}-doped NaYF{sub 4}:Yb/Er NPs with good water solubility are obtained. - Highlights: • Homogeneous size distribution of magnetic-upconversion core@shell structured nanoparticles (NPs) were synthesized. • The core@shell nanostructures were obtained by seed-growth method. • The oleic acid coated Fe{sub 3}O{sub 4} NPs were used as seeds and cores. • The magnetic-upconversion NPs emitted red luminescence under a 980 nm laser. • Synthesized magnetic-upconversion NPs were phase transferred using ligand exchange process. - Abstract: We report the use of an efficient hydrothermal method to synthesize superparamagnetic and red luminescent bifunctional Fe{sub 3}O{sub 4}@Mn{sup 2+}-doped NaYF{sub 4}:Yb/Er nanoparticles (NPs) with core@shell structures via a seed-growth procedure. Oleic acid coated Fe{sub 3}O{sub 4} (OA-Fe{sub 3}O{sub 4}) NPs were initially synthesized using a coprecipitation method. The as-synthesized OA-Fe{sub 3}O{sub 4} NPs were then used as seeds, on which the red upconversion luminescent shell (Mn{sup 2+}-doped NaYF{sub 4}:Yb/Er) was formed. Furthermore, hydrophobic to hydrophilic surface modification of the Fe{sub 3}O{sub 4}@Mn{sup 2+}-doped NaYF{sub 4}:Yb/Er NPs was achieved via a ligand exchange method where oleic acid was displaced by a PEG phosphate ligand [PEG = poly(ethylene glycol)]. These materials were characterized by means of transmission electron microscopy (TEM), X-ray diffraction (XRD), photoluminescence (PL) spectroscopy, and vibrating sample magnetometry (VSM). The Fe{sub 3}O{sub 4} cores were uniformly coated with a Mn{sup 2+}-doped NaYF{sub 4}:Yb

Evolution of magnetic properties and exchange interactions in Ru doped YbCrO3

International Nuclear Information System (INIS)

Dalal, Biswajit; Sarkar, Babusona; De, S K; Dev Ashok, Vishal

2016-01-01

Magnetic properties of YbCr 1−x Ru x O 3 as a function of temperature and magnetic field have been investigated to explore the intriguing magnetic phenomena in rare-earth orthochromites. A quantitative analysis of x-ray photoelectron spectroscopy confirms the mixed valence state (Yb 3+  and Yb 2+ ) of Yb ions for the highest doped sample. Field-cooled magnetization reveals a broad peak around 75 K and then becomes zero at about 20–24 K, due to the antiparallel coupling between Cr 3+ and Yb 3+ moments. An increase of the Ru 4+ ion concentration leads to a slight increase of compensation temperature T comp from 20 to 24 K, but the Néel temperature remains constant. A larger value of the magnetic moment of Yb ions gives rise to negative magnetization at low temperature. An external magnetic field significantly modifies the temperature dependent magnetization. Simulation of temperature dependent magnetization data, below T N , based on the three (two) magnetic sub-lattice model predicts stronger intra-sublattice exchange interaction than that of inter-sublattice. Thermal hysteresis and Arrot plots suggest first order magnetic phase transition. Random substitution of Ru 4+ ion reduces the magnetic relaxation time. Weak ferromagnetic component in canted antiferromagnetic system and negative internal magnetic field cause zero-field-cooled exchange bias effect. Large magnetocrystalline anisotropy associated with Ru creates high coercivity in the Ru doped sample. A maximum value of magnetocaloric effect is found around the antiferromagnetic ordering of Yb 3+ ions. Antiferromagnetic transition at about 120 K and temperature induced magnetization reversal lead to normal and inverse magnetocaloric effects in the same material. (paper)

Investigations on luminescence behavior of Er3+/Yb3+ co-doped boro-tellurite glasses

Science.gov (United States)

Maheshvaran, K.; Arunkumar, S.; Venkata Krishnaiah, K.; Marimuthu, K.

2015-01-01

Er3+/Yb3+ co-doped boro-tellurite glasses with the chemical composition 30TeO2+(24 - x)B2O3 + 15SrO + 10BaO + 10Li2O + 10LiF + 1Er2O3 + xYb2O3 (where x = 0, 0.1, 0.5, 1 and 2 in wt%) have been prepared and their luminescence behavior were studied and reported. Absorption spectral measurements have been used to derive the Judd-Ofelt (JO) intensity parameters from the experimental and calculated oscillator strength values following the JO theory. The various lasing parameters such as stimulated emission cross-section (σEp), experimental and calculated branching ratios (βR) and radiative lifetime (τcal) for the 2H9/2 → 4I15/2, 4S3/2 → 4I15/2 and 4I13/2 → 4I15/2 emission transitions were determined using the JO intensity parameters. The absorption and emission cross-section values for the 4I13/2 → 4I15/2 emission band have been calculated using McCumbar theory and the Gain cross-section for the 4I13/2 → 4I15/2 emission transition also obtained. The upconversion emission mechanism have been studied through various energy transfer processes and the intensity of the upconversion emission transitions are found to increase with the increase in Yb3+ ion concentration. The luminescence decay curves corresponding to the 4I13/2 → 4I15/2 transition of the Er3+/Yb3+ co-doped boro-tellurite glasses under 980 nm excitation wavelength have also been studied and reported in the present work.

Enhanced frequency upconversion study in Er3+/Yb3+ doped/codoped TWTi glasses

Science.gov (United States)

Azam, Mohd; Rai, Vineet Kumar

2018-04-01

Er3+/Yb3+ doped/codoped TeO2-WO3-TiO2 (TWTi) glasses have been prepared by using the melt-quenching technique. The upconversion (UC) emission spectra of the developed glasses have been recorded upon 980 nm laser excitation. Three intense UC emission bands have been observed within the green and red region centered at ˜532 nm, ˜553 nm and ˜669 nm corresponding to the 2H11/2→4I15/2, 4S3/2→4I15/2 and 4F9/2→4I15/2 transitions respectively in the singly Er3+ doped glass. On introducing Yb3+ ions in the singly Er3+ doped glass, an enhancement of about ˜ 12 times and ˜50 times in the green and red bands respectively have been observed even at low pump power ˜ 364 mW followed by two photon absorption process. Colour tunability from yellowish green to pure green colour region has been observed on varying the pump power. The prepared glass can be used to produce NIR to green upconverter and colour tunable display devices.

Nd(BrO3)3-Yb(BrO3)3-H2O and Nd2(SeO4)3-Yb2(SeO4)3-H2O systems at 25 deg C

International Nuclear Information System (INIS)

Serebrennikov, V.V.; Batyreva, V.A.; Tsybukova, T.N.

1981-01-01

Using the methods of isothermal solubility the Nd(BrO 3 ) 3 - Yb(BrO 3 ) 3 -H 2 O and Nd 2 (SeO 4 ) 3 -Yb 2 (SeO 4 ) 3 -H 2 O systems are studied at 25 deg C. The compositions of the solid phases are determined by the method of ''residues''. The formation of two series of solid solutions in both systems is established. Besides, there is a crystallization region of Nd 2 (SeO 4 ) 3 in the system of selenates. The solubility diagrams of the systems are presented [ru

Conductivity of A- and B-site doped LaAlO3, LaGaO3, LaScO3 and LaInO3 perovskites

DEFF Research Database (Denmark)

Lybye, D.; Poulsen, F.W.; Mogensen, Mogens Bjerg

2000-01-01

The conductivity of the materials LaAlO3, LaGaO3, LaScO3 and LaInO3 all doped with 10% strontium on the A-site and 10% magnesium at the B-site has been measured at different temperatures and oxygen partial pressures. The doped LaGaO3 is found to be an almost pure ionic conductor with a conductivi...

Two anionically derivatized scandium oxoselenates(IV): ScF[SeO3] and Sc2O2[SeO3

Science.gov (United States)

Greiner, Stefan; Chou, Sheng-Chun; Schleid, Thomas

2017-02-01

Scandium fluoride oxoselenate(IV) ScF[SeO3] and scandium oxide oxoselenate(IV) Sc2O2[SeO3] could be synthesized through solid-state reactions. ScF[SeO3] was obtained phase-pure, by reacting mixtures of Sc2O3, ScF3 and SeO2 (molar ratio: 1:1:3) together with CsBr as fluxing agent in corundum crucibles embedded into evacuated glassy silica ampoules after firing at 700 °C for seven days. Sc2O2[SeO3] first emerged as by-product during the attempts to synthesize ScCl[SeO3] following aforementioned synthesis route and could later be reproduced from appropriate Sc2O3/SeO3 mixtures. ScF[SeO3] crystallizes monoclinically in space group P21/m with a=406.43(2), b =661.09(4), c=632.35(4) pm, β=93.298(3)° and Z=2. Sc2O2[SeO3] also crystallizes in the monoclinic system, but in space group P21/n with a=786.02(6), b=527.98(4), c=1086.11(8) pm, β=108.672(3)° for Z=4. The crystal structures of both compounds are strongly influenced by the stereochemically active lone pairs of the ψ1-tetrahedral [SeO3]2- anions. They also show partial structures, where the derivatizing F- or O2- anions play an important role. For ScF[SeO3] chains of the composition 2+∞ 1[FS c 2 / 2 ] form from connected [FSc2]5+ dumbbells, while [OSc3]7+ pyramids and [OSc4]10+ tetrahedra units are condensed to layers according to 2+ ∞ 2[O2Sc2 ] in Sc2O2[SeO3].

Characterization and Computation of Yb/TiO2 and Its Photocatalytic Degradation with Benzohydroxamic Acid

Directory of Open Access Journals (Sweden)

Xianping Luo

2017-11-01

Full Text Available Yb-doped TiO2 (Yb/TiO2 compositions were synthesized by sol-gel method, and the prepared materials were characterized by X-ray Diffraction (XRD, X-ray photoelectron spectroscopy (XPS, UV-visible diffuse-reflectance spectrum (UV-Vis DRS, transmission electron microscope (TEM and high resolution transmission electron microscope (HRTEM, energy dispersive spectrometer (EDS, and N2 adsorption. A beneficiation reagent of benzohydroxamic acid (BHA was used to test the photocatalytic activity of Yb/TiO2. The characterizations indicate that the doping of Yb could inhibit the crystal growth of TiO2, enhance the specific surface area, increase the binding energy of Ti2p, and also slightly expand the adsorption ranges to visible light. Furthermore, the computation of band structure also indicates that Yb-doped TiO2 could make the forbidden band narrower than pure anatase TiO2, which presents a red shift in the absorption spectrum. As a result of the photodegradation experiment on BHA, Yb/TiO2 (0.50% in mass sintered at 450 °C displayed the highest catalytic activity for BHA when compared with pure TiO2 or other doped Yb/TiO2 compositions, and more than 89.2% of the total organic carbon was removed after 120 min. Almost all anions, including Cl−, HCO3−, NO3−, and SO42−, inhibited the degradation of BHA by Yb/TiO2, and their inhibition effects followed the order of HCO3− > NO3− > SO42− > Cl−. Cations of Na+, K+, Ca2+, and Mg2+ displayed a slight suppressing effect due to the impact of Cl− coexisting in the solution. In addition, Yb/TiO2 maintained a high photocatalytic ability with respect to BHA after four runs. It is hypothesized that ·OH is one of the main species involved in the photodegradation of BHA, and the mutual transformation of Yb3+ and Yb2+ could promote the separation of electron-hole pairs.

Combustion synthesis and photoluminescence properties of LaAlO{sub 3} nanophosphors doped with Yb{sup 3+} ions

Energy Technology Data Exchange (ETDEWEB)

Dhahri, A. [Laboratoire de Physico-chimie des Matériaux Minéraux et leurs Applications, Centre National des Recherches en Sciences des Matériaux, Technopole de Borj Cedria, B.P. 73, Soliman 8027 (Tunisia); Horchani-Naifer, K., E-mail: karima_horchani@yahoo.com [Laboratoire de Physico-chimie des Matériaux Minéraux et leurs Applications, Centre National des Recherches en Sciences des Matériaux, Technopole de Borj Cedria, B.P. 73, Soliman 8027 (Tunisia); Benedetti, A. [Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, Dorsoduro 2137, 30123 Venezia (Italy); Enrichi, F. [CIVEN – Coordinamento Interuniversitario Veneto per le Nanotecnologie, Via Delle Industrie 5, Marghera, Venice 30175 (Italy); Ferid, M. [Laboratoire de Physico-chimie des Matériaux Minéraux et leurs Applications, Centre National des Recherches en Sciences des Matériaux, Technopole de Borj Cedria, B.P. 73, Soliman 8027 (Tunisia)

2014-09-15

Ytterbium doped lanthanum aluminate (LaAlO{sub 3}) nanophosphors have been prepared by a combustion process with glycine as a fuel. The structures of the powders were determined by X-ray diffraction (XRD), the morphology of the annealed materials was observed using scanning electron microscopy (SEM), the average crystalline grain sizes have been determined by transmission electron microscopy (TEM) and photoluminescence properties using fluorescence spectroscopy. Pure LaAlO{sub 3} phase was obtained at 800 °C heated for 4 h, with an average crystal size, as determined by TEM, of 60 nm. Emission spectra and decay times of main luminescence transitions were measured at room temperature. A strong emission is reported at 986 nm from the ({sup 2}F{sub 5/2}→{sup 2}F{sub 7/2}) transition, whose intensity depends on Yb concentration. - Highlights: • Ytterbium doped lanthanum aluminate (LaAlO{sub 3}) nanophosphors have been prepared by a combustion process with glycine as a fuel. • Powders were characterized by DRX, FTIR, TEM and fluorescence spectroscopy. • Pure LaAlO{sub 3} phase was obtained at 800 °C heated for 4 h, with an average crystal size of 60 nm. • A strong emission is reported at 986 nm from the ({sup 2}F{sub 5/2}→{sup 2}F{sub 7/2}) transition, whose intensity depends on Yb concentration.

Infrared emissions in MgSrAl{sub 10}O{sub 17}:Er{sup 3+} phosphor co-doped with Yb{sup 3+}/Ba{sup 2+}/Ca{sup 2+} obtained by solution combustion route

Energy Technology Data Exchange (ETDEWEB)

Singh, Vijay, E-mail: vijayjiin2006@yahoo.com [Physical Chemistry, Institute for Pure and Applied Chemistry and Center of Interface Science, University of Oldenburg, 26129 Oldenburg (Germany); Kumar Rai, Vineet [Department of Applied Physics, Indian School of Mines, Dhanbad 826 004 (India); Venkatramu, V. [Department of Physics, Yogi Vemana University, Kadapa 516 003 (India); Chakradhar, R.P.S. [CSIR-National Aerospace, Bangalore 560 017 (India); Hwan Kim, Sang [Department of Chemical Engineering, Konkuk University, Seoul 143-701 (Korea, Republic of)

2013-02-15

An intense infrared emitting MgSrAl{sub 10}O{sub 17}:Er{sup 3+} phosphor co-doped with Yb{sup 3+}, Ba{sup 2+} and Ca{sup 2+} ions have been prepared by a solution combustion method. Phase purity of the derived compounds was confirmed by X-ray diffraction technique. The vibrational properties of MgSrAl{sub 10}O{sub 17} phosphor was studied by Fourier transform infrared spectroscopy. The broad and strong infrared emission of Er{sup 3+} ions at around 1.53 {mu}m was observed upon excitation at 980 nm. Effect of co-doping with the Yb{sup 3+}{sub ,} Ba{sup 2+} and Ca{sup 2+} ions on the infrared luminescence intensity of Er{sup 3+} ions and the mechanism responsible for the variation in the infrared intensity have been discussed. The results indicate that these materials may be suitable for the optical telecommunication window and wavelength division multiplexing applications. - Highlights: Black-Right-Pointing-Pointer The hexagonal phase of MgSrAl{sub 10}O{sub 17} could be obtained by the low temperature combustion method. Black-Right-Pointing-Pointer The broad and strong infrared emission of Er{sup 3+} ions at around 1.53 {mu}m was observed. Black-Right-Pointing-Pointer Effect of co-doping with the Yb{sup 3+}{sub ,} Ba{sup 2+} and Ca{sup 2+} ions on the infrared luminescence intensity of Er{sup 3+} were reported.

Enhanced infrared-to-visible up-conversion emission and temperature sensitivity in (Er3+,Yb3+, and W6+) tri-doped Bi4Ti3O12 ferroelectric oxide

Science.gov (United States)

Bokolia, Renuka; Mondal, Manisha; Rai, V. K.; Sreenivas, K.

2017-02-01

Strong up conversion (UC) luminescence at 527, 550, and 662 nm is compared under an excitation of 980 nm in single doped (Er3+), co-doped (Er3+/Yb3+), and (Er3+/Yb3+/W6+) tri-doped bismuth titanate (Bi4Ti3O12). For the co-doped system, the frequency (UC) emission intensity due to Er3+ ions is enhanced significantly in the green bands due to the efficient energy transfer from Yb3+ to Er3+ ions. Further increase in the emission intensity is seen with non-luminescent W6+ ions in the tri-doped system due to the modification in the local crystal field around the Er3+ ions, and is evidenced through a gradual change in the crystal structure of the host lattice with increasing W6+ content. The observed changes in the fluorescence lifetime and the associated energy transfer mechanisms are discussed. A progressive reduction of the lifetime of the 4S3/2 levels of Er3+ ions from 72 to 58.7 μs with the introduction of Yb3+ and W6+ dopant increases the transition probability and enhances the UC emission intensity. The efficiency of the energy transfer process ( η ) in the co-doped and tri-doped systems is found to be 9.4% and 18.6%, respectively, in comparison to the single doped system. Temperature sensing based on the fluorescence intensity ratio (FR) technique shows high sensitivity (0.0123 K-1) in the high temperature range (293 to 523 K) for an optimum content of Er3+, Yb3+, and W6+ with x = 0.03, y = 0.18, and z = 0.06 at. % in the tri-doped Bi4-x-yErxYbyTi3-zWzO12 ferroelectric composition, and is found useful for potential applications in optical thermometry.

Design, synthesis and luminescence properties of Ba2 YB2 O6 Cl- and Ba2 YB2 O6 F-based phosphors.

Science.gov (United States)

Chen, Wanping; Yang, Xin; Liu, Yan; Dai, Xiaoyan

2015-05-01

Using a high-temperature solid-state reaction, the chlorine in Ba2 YB2 O6 Cl is gradually replaced by F, and a new compound with the nominal chemical formula Ba2 YB2 O6 F and two phosphors doped with Ce(3+) and Eu(3+) , respectively, are obtained. X-Ray diffraction and photoluminescence spectroscopy are used to characterize the as-synthesized samples. The as-synthesized Ba2 YB2 O6 Cl exhibits bright blue emission in the spectral range ~ 330-410 nm with a maximum around 363 nm under X-ray or UV excitation. Ba2 YB2 O6 F:0.01Ce(3+) exhibits blue emission in the range ~ 340-570 nm with a maximum around 383 nm. Ba2 YB2 O6 F:0.01Eu(3+) exhibits a predominantly (5) D0 -(7)  F2 emission (~610 nm) and the relative intensities of the (5) D0 -(7)  F0,1,2 emissions are tunable under different wavelength UV excitation. The luminescence behaviors of the two phosphors are explained simply in terms of the host composition and site occupancy probability of Ce(3+) and Eu(3+) , respectively. The results indicate that these phosphors have potential application as a blue phosphor or as a red phosphor. Copyright © 2014 John Wiley & Sons, Ltd.

Up-conversion emission of Er{sup 3+}/Yb{sup 3+}co-doped BaBi{sub 2}Nb{sub 2}O{sub 9} (BBN) phosphors

Energy Technology Data Exchange (ETDEWEB)

Façanha, M.X., E-mail: marcello.facanha@uece.br [Departamento de Química, Centro de Ciências, Universidade Federal do Ceará (UFC), Fortaleza, Ceará (Brazil); Faculdade de Educação de Crateús (FAEC), Universidade Estadual do Ceará (UECE), Fortaleza, Ceará (Brazil); Laboratório de Telecomunicações e Ciências e Engenharia de Materiais (LOCEM), Universidade Federal do Ceará (UFC), Fortaleza, Ceará (Brazil); Nascimento, J.P.C. do [Departamento de Química, Centro de Ciências, Universidade Federal do Ceará (UFC), Fortaleza, Ceará (Brazil); Laboratório de Telecomunicações e Ciências e Engenharia de Materiais (LOCEM), Universidade Federal do Ceará (UFC), Fortaleza, Ceará (Brazil); Silva, M.A.S., E-mail: marceloassilva@yahoo.com.br [Laboratório de Telecomunicações e Ciências e Engenharia de Materiais (LOCEM), Universidade Federal do Ceará (UFC), Fortaleza, Ceará (Brazil); and others

2017-03-15

On this paper, polycrystalline samples of the tetragonal systems BaBi{sub 2}Nb{sub 2}O{sub 9} (BBN) and BBN co-doped with Er{sup 3+}/Yb{sup 3+} (BBN: 0.04Er{sup 3+}yYb{sup 3+}, where y=0.02, 0.04, 0.06 and 0.08 mol%) were synthesized by the solid state method. The crystalline structure and photoluminescent properties of the ceramic phosphors were investigated by powder X-ray diffraction (PXRD), Raman spectroscopy and spectral analysis of up-conversion (UC) emission. The results reveal that all compositions crystallize in the I4/mmm space group at room temperature, and show UC green emissions (centered at 525 nm and 550 nm) and red (around 660 nm) coming from ({sup 2}H{sub 11/2}, {sup 4}S{sub 3/2}→{sup 4}I{sub 15/2}) and ({sup 4}F{sub 9/2}→{sup 4}I{sub 15/2}) transitions, respectively, under excitation at 980 nm. Increasing variations of the Yb{sup 3+} sensitizer concentration in the host BBN, lead to a significant intensity increase in both UC emissions due to the efficiency of the energy-transfer process. The BBN: 0.04 mol%Er{sup 3+}0.08 mol%Yb{sup 3+} composition showed the higher intensity bands, thus establishing the BBN as an alternative host material for luminescent centers.

Co-operative energy transfer in Yb3+-Er3+ co-doped SrGdxOy upconverting phosphor

Science.gov (United States)

Kumar, Ashwini; Pathak, Trilok K.; Dhoble, S. J.; . Terblans, J. J.; Swart, H. C.

2018-04-01

Upconversion nanoparticles (UCNPs) have shown considerable interest in many fields; however, low upconversion efficiency of UCNPs is still the most severe limitation of their applications. Yb3+ and Er3+ co-doped SrGd4O7/Gd2O3(SGO) upconversion (UC) phosphors were synthesized by a modified co-precipitation process. The UC properties were investigated by direct excitation with a 980 nm laser. It was observed that the as prepared materials showed relatively strong green emission, while upon the incorporation of the Er3+ ion, there was an increase in the upconversion luminescence intensity for the red component. The effect of different doping concentration of Er3+on the emission spectra and X-ray diffraction patterns of the UC materials have also been studied. The luminescence lifetimes and Commission Internationale de L'Eclairage coordinates for these as prepared samples were determined to understand the energy transfer (ET) mechanisms occurring between Yb3+ and Er3+ in the SGO host matrix. The UC luminescence intensity as a function of laser pump power was monitored and it was confirmed that the UC process in SGO:Yb3+/Er3+is a two-photon absorption process. The findings reported here are expected to provide a better approach for understanding of the ET mechanisms in the oxide based Yb3+/Er3+ co-doped UC phosphors. This study might be helpful in precisely defined applications where optical transitions are essential criterion and this can be easily achieved by smart tuning of the emission properties of Yb3+/Er3+ co-doped UC phosphors.

Study of upconversion fluorescence property of novel Er3+/Yb3+ co-doped tellurite glasses.

Science.gov (United States)

Xu, Tie-Feng; Li, Guang-Po; Nie, Qiu-Hua; Shen, Xiang

2006-06-01

Er3+/Yb3+ co-doped TeO2-B2O3-Nb2O5-ZnO (TBN) glasses were prepared. The absorption spectra and upconversion luminescence spectra of TBN glasses were measured and analyzed. The upconversion emission bands centered at 530, 546 and 658 nm were observed under the excitation at 975 nm, corresponding to the transitions of 2H11/2-->4I15/2, 4S3/2-->4I15/2 and 4F9/2-->4I15/2 respectively. The ratio of red emission to green emission increases with an increasing of Yb3+ ions concentration. According to the quadratic dependence on excitation power, the possible upconversion mechanisms and processes were discussed.

New Ce{sup 3+} doped Ca{sub 2}YMgScSi{sub 3}O{sub 12} garnet ceramic phosphor for white LED converters

Energy Technology Data Exchange (ETDEWEB)

Khaidukov, N. [Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Moscow (Russian Federation); Zorenko, Yu.; Zorenko, T.; Iskaliyeva, A.; Paprocki, K. [Institute of Physics, Kazimierz Wielki University Bydgoszcz (Poland); Zhydachevskii, Y.; Suchocki, A. [Institute of Physics, Polish Academy of Sciences, Warsaw (Poland); Deun, R. van [L3 - Luminescent Lanthanide Lab, Department of Inorganic and Physical Chemistry, Ghent University (Belgium); Batentschuk, M. [Department of Materials Science and Engineering VI, Institute of Materials for Energy and Electronic Technology (i-IMEET), University of Erlangen-Nuremberg, Erlangen (Germany)

2017-05-15

The results on crystallization and investigation of the luminescent properties of a new prospective ceramic phosphor based on the Ce{sup 3+} doped Ca{sub 2}YMgScSi{sub 3}O{sub 12} silicate garnet are presented for the first time in this work. The luminescent properties of Ca{sub 2}YMgScSi{sub 3}O{sub 12}:Ce were compared with the properties of the reference Ca{sub 3}Sc{sub 2}Si{sub 3}O{sub 12}:Ce ceramic sample. Without any doubt, the results of this research can be suitable for the development of a new generation of white converters based on the Ca{sup 2+}-Si{sup 4+} garnet compounds. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

The effect of micro-structure on upconversion luminescence of Nd3+/Yb3+ co-doped La2O3-TiO2-ZrO2 glass-ceramics

Science.gov (United States)

Zhang, Minghui; Wen, Haiqin; Pan, Xiuhong; Yu, Jianding; Jiang, Meng; Yu, Huimei; Tang, Meibo; Gai, Lijun; Ai, Fei

2018-03-01

Nd3+/Yb3+ co-doped La2O3-TiO2-ZrO2 glasses have been prepared by aerodynamic levitation method. The glasses show high refractive index of 2.28 and Abbe number of 18.3. Glass-ceramics heated at 880 °C for 50 min perform the strongest upconversion luminescence. X-ray diffraction patterns of glass-ceramics with different depths indicate that rare earth ions restrain crystallization. Body crystallization mechanism mixed with surface crystallization is confirmed in the heat treatment. Surface crystals achieve priority to grow, resulting in important effects on upconversion luminescence. The results of atomic force microscope and scanning electron microscope indicate that crystal particles with uniform size distribute densely and homogenously on the surface and large amount of glass matrix exists in the glass ceramics heated at 880 °C for 50 min. Crystals in the glass-ceramics present dense structure and strong boundaries, which can reduce the mutual nonradiative relaxation rate among rare earth ions and then improve upconversion luminescence effectively. Based on micro-structural study, the mechanism that upconversion luminescence can be improved by heat treatment has been revealed. The results of micro-structural analysis agree well with the spectra.

Al2O3 influence on structural, elastic, thermal properties of Yb(3+) doped Ba-La-tellurite glass: evidence of reduction in self-radiation trapping at 1μm emission.

Science.gov (United States)

Balaji, S; Biswas, K; Sontakke, A D; Gupta, G; Ghosh, D; Annapurna, K

2014-12-10

Ba-La-tellurite glasses doped with Yb(3+) ions have been prepared through melt quenching technique by modifying their composition with the inclusion of varied concentration of Al2O3 to elucidate its effects on glass structural, elastic, thermal properties and Yb(3+) ion NIR luminescence performance. The FTIR spectral analysis indicates Al2O3 addition is promoting the conversion of BOs from NBOs which have been generated during the process of depolymerisation of main glass forming TeO4 units. The elastic properties of the glass revealed an improved rigidity of the glass network on addition of Al2O3. In concurrence to this, differential thermal analysis showed an increase in glass transition temperature with improved thermal stability factor. Also, Yb(3+) fluorescence dynamics demonstrated that, Al2O3 inclusion helps in restraining the detrimental radiation trapping of ∼1μm emission. Copyright © 2014 Elsevier B.V. All rights reserved.

New configurations for short-pulses high power solid-state lasers: conception and realization of highly doped waveguide amplifiers/lasers grown by liquid phase epitaxy and demonstration of Y2SiO5: Yb and Lu2SiO5: Yb femtosecond lasers

International Nuclear Information System (INIS)

Thibault, F.

2006-04-01

Yb-doped yttrium and lutetium ortho-silicates, Y 2 SiO 5 :Yb and Lu 2 SiO 5 :Yb respectively, exhibit spectroscopic properties favorable to an efficient laser operation in both high power cw and femtosecond regime. Their first diode-pumped femtosecond operation demonstration lead to exceptional performances in terms of output power and efficiency. In order to realize compact and efficient solid-state laser devices using those materials, we chose a configuration with an Yb-doped medium planar waveguide geometry, grown by liquid phase epitaxy, face-pumped by a single laser diode bar. The growth of highly doped Y 2 SiO 5 :Yb layers, within a large range of compositions and thicknesses, was demonstrated. The refractive index increase due to the substitution of the various dopants is analyzed. The layers spectroscopic properties are similar to the bulk ones, with an noticeably higher crystalline quality. The Yb ion lifetime evolution with respect to its doping shows up a particularly low decrease, proof of a low concentration of extrinsic quenching centers. The covered YSO:24%Yb waveguides exhibit lower than 0.3 dB/cm propagation losses, and provided up to 2.9 dB/cm net amplification at 1082 nm with a single mode output. The realization of the first diode-pumped monolithic cw waveguide lasers was also demonstrated. For a 4% output coupler, they provided up to 340 mW at 1082 nm with a 14% slope efficiency. (author)

Up conversion luminescence of Yb3+–Er3+ codoped CeO2 nanocrystals with imaging applications

International Nuclear Information System (INIS)

Cho, Jung-Hyun; Bass, Michael; Babu, Suresh; Dowding, Janet M.; Self, William T.; Seal, Sudipta

2012-01-01

The effects of Yb 3+ doping on up conversion in Yb 3+ –Er 3+ co-doped cerium oxide nanocrystals are reported. Green emission around 545 and 560 nm attributed to the 2 H 11/2 , 4 S 3/2 → 4 I 15/2 transitions and red emission around 660 and 680 nm due to 4 F 9/2 → 4 I 15/2 transitions under 975 nm excitation were studied at room temperature. Both green and red emission intensities increase as the Yb 3+ concentration increases from 0%. Emission strength starts to decrease after the Yb 3+ concentration exceeds a critical amount. The green emission strength peaks around 1% Yb 3+ concentration while the red emission strength peaks around 4%. An explanation of competition between different decay mechanisms is presented to account for the luminescence dependence on Yb 3+ concentration. Also, the application of up converting nanoparticles in biomedical imaging is demonstrated. - Highlights: ► Up conversion in Yb 3+ –Er 3+ co-doped cerium oxide nanocrystals. ► Different decay mechanisms determine luminescence efficiency. ► Up converting nanoparticles in biomedical imaging is demonstrated.

Structural and magnetic properties of Mg doped YbMnO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Sattibabu, Bhumireddi, E-mail: bsb.satti@gmail.com [School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad 500046 (India); Bhatnagar, Anil K., E-mail: anilb42@gmail.com [School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad 500046 (India); School of Physics, University of Hyderabad, Hyderabad 500046 (India); Rayaprol, Sudhindra [UGC-DAE CSR, Mumbai Centre, R-5 Shed, BARC, Mumbai 400085 (India); Mohan, Dasari; Das, Dibakar; Sundararaman, Mahadevan [School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad 500046 (India); Siruguri, Vasudeva [UGC-DAE CSR, Mumbai Centre, R-5 Shed, BARC, Mumbai 400085 (India)

2014-09-01

We have studied the effect of Mg doping on structure and magnetism of multiferroic YbMnO{sub 3}. Room temperature neutron diffraction studies were carried out on polycrystalline Yb{sub 1−x}Mg{sub x}MnO{sub 3} (x=0.00 and 0.05) samples to determine phase formation as well as cation distribution and structural properties such as bond length and bond angles. The structural analysis shows that with Mg substitution, there is a marginal change in a and c parameters of the hexagonal unit cell, c/a ratio remains constant for x=0 and 0.05 samples. Due to changes in bond angle and bond lengths on substituting Mg, there is a slight decrease in the distortion of MnO{sub 5} polyhedra. Magnetic measurements show that the Néel temperature (T{sub N}) increases marginally from 85 K for x=0.00 to 89 K for x=0.05 sample.

Effect of air annealing on the color center in Yb:Y3Al5O12 transparent ceramics with MgO as sintering additive

Science.gov (United States)

Lu, Zhongwen; Lu, Tiecheng; Wei, Nian; Zhang, Wei; Ma, Benyuan; Qi, Jianqi; Guan, Yongbing; Chen, Xingtao; Wu, Huajun; Zhao, Yu

2015-09-01

High quality Yb:Y3Al5O12 (YAG) transparent ceramics were fabricated by vacuum sintering with MgO as sintering aids. The Yb:YAG samples were annealed at 1250-1450 °C for 20 h in air. The experimental results showed that the transparency of Yb:YAG samples declined markedly with the annealing temperatures of 1250-1450 °C. The samples became increasingly orange-yellow in color with the increase of annealing temperature. The potential reasons of discoloration were discussed for the first time. It was attributed to the complex color center [Mg2+F+] formed during the annealing, which was evidenced by optical absorption in the range of 300-500 nm wavelength and the presence of an electron spin resonance (ESR) line at g = 1.9806. The formation mechanism of the complex color center was explained in detail. The complex color center can be eliminated after post-HIP (hot isostatic pressing). And by air annealing and post-HIP, the transmittance of the samples increased from 80.3% to 83.4%.

ZnMoO4:Er3+,Yb3+ phosphor with controlled morphology and enhanced upconversion through alkali ions doping

Science.gov (United States)

Luitel, Hom Nath; Chand, Rumi; Watari, Takanori

2018-04-01

A facile hydrothermal method was used to synthesize ZnMoO4:Er3+,Yb3+ nanoparticles. The shapes and sizes of the nanoparticles were well tuned by simply monitoring the pH of the starting solution. Microballs consisting of agglomerated nanograins were observed at strong acidic condition. At mild pH, plates and rectangular particles were realized, while strong basic pH stabilized rods. Further increasing pH to extremely basic conditions (pH > 13), rods changed to fragile hairy structures. The nucleation and growth mechanism of nanograins to form different morphology nanoparticles were studied and illustrated. XRD patterns confirmed well crystalline, triclinic structure despite small amount of aliovalent metal ions doping. Under 980 nm excitation, the ZnMoO4:Er3+,Yb3+ nanophosphor exhibited strong green (centered at 530 and 560 nm) and weak red (centered at 660 nm) upconversion (UC) emissions. Substitution of part of the Zn2+ ions by monovalent alkali ions intensified the UC emission intensities drastically. The order of intensification was K+>Na+>Li+>Rb+>no alkali ion. When Zn2+ ions were substituted with 10 at% K+ ions, the green and red UC emissions intensities increased by more than 50 and 15 folds, respectively. Time dependent measurements confirmed efficient Yb to Er energy transfer in the ZnMoO4:Er3+,Yb3+,K+ nanophosphor. The optimized ZnMoO4:Er3+,Yb3+,K+ phosphor exhibited intense UC emissions with 0.31% quantum yield. The upconverted light is visible to naked eye while pumping by laser of less than 1 mW power and opens door for variety of novel applications.

Phase equilibria in the system Li2O - MoO3 - Sc2O3

International Nuclear Information System (INIS)

Safonov, V.V.; Chaban, N.G.; Porotnikov, N.V.

1984-01-01

Using the methods of DTA and X-ray phase analysis, interaction of components in the system Li 2 O-MoO 3 -Sc 2 O 3 in concentration range, adjacent to the vertex of MoO 3 , has been studied. Projection of the Li 2 MoO 4 -MoO 3 -Sc 2 (MoO 4 ) 3 system liquidus on concentrational triangle of the compositions Li 2 O-MoO 3 -Sc 2 O 3 , which consists of the fields of primary separation of Li 2 MoO 4 , Li 2 Mo 5 O 17 , Li 2 Mo 4 O 13 , MoO 3 , Sc 2 (MoO 4 ) 3 , Li 3 Sc(MoO 4 ) 3 and LiSc(MoO 4 ) 2 , is built

Spectroscopy and visible frequency upconversion in Er3+-Yb3+: TeO2-ZnO glass.

Science.gov (United States)

Mohanty, Deepak Kumar; Rai, Vineet Kumar

2014-01-01

The UV-Vis-NIR absorption studies of the Er(3+)/Er(3+)-Yb(3+) doped/codoped TeO2-ZnO (TZO) glasses fabricated by the melting and quenching method has been performed. The spectroscopic radiative parameters viz. radiative transition probabilities, branching ratios and lifetimes have been determined from the absorption spectrum by using Judd-Ofelt theory. The near infrared (NIR) to visible frequency upconversion (UC) have been monitored by using an excitation of 976 nm wavelength radiation from a CW diode laser. The effect of codoping with Yb(3+) ions on the intensity of the UC emission bands from the Er(3+) ions throughout visible region has been studied. The mechanism responsible for the observed upconversion emissions in the prepared samples have been explained on the basis of excited state absorption and efficient energy transfer processes. Copyright © 2013 Elsevier B.V. All rights reserved.

Crystal growth and spectroscopic characterization of Yb3+:LiTaO3

International Nuclear Information System (INIS)

Gruber, John B.; Allik, Toomas H.; Sardar, Dhiraj K.; Yow, Raylon M.; Scripsick, Michael; Wechsler, Barry

2006-01-01

Spectroscopic properties are presented for Yb 3+ incorporated into single crystals of LiTaO 3 grown by the top-seeded solution growth method. From an analysis of the absorption and fluorescence spectra, we are able to determine the Stark-level components of the 2 F 7/2 (the ground-state multiplet manifold) and the 2 F 5/2 (the excited-state multiplet manifold of Yb 3+ (4f 13 )). The room-temperature fluorescence lifetime of 2 F 5/2 is 678μs as measured on a thin sample to reduce possibilities for reabsorption. Spectral comparisons of Yb 3+ -doped LiTaO 3 and LiNbO 3 are drawn. The crystal-field splitting of Yb 3+ (4f 13 ) in both crystal hosts is modeled using a set of crystal-field splitting parameters, B nm , determined from a recent spectroscopic analysis of Er 3+ (4f 11 ) in LiNbO 3 . Without adjustment of the B nm parameters, the model predicts the Stark-level energy and the symmetry label for each level in reasonable agreement with the experimental values. Less photorefractive than its niobate cousin, LiTaO 3 has potential for use in numerous integrated electro-optical circuits and devices

Mass fabrication of homogeneously Yb-doped silica nanoparticles and their spectroscopic properties

International Nuclear Information System (INIS)

Xiong Liangming; Sekiya, Edson H; Saito, Kazuya

2009-01-01

A large number of homogeneously Yb-doped silica nanoparticles were continually fabricated in a vapor synthesis route, in which the Yb doping level can be well controlled by varying either the heating temperature or the carrier gas flow rate of the Yb precursor. The sizes, shapes, and morphologies of the nanoparticles were examined, and no crystallites and no Yb 2 O 3 clusters were observed in the nanoparticles. These nanoparticles exhibit a clear Yb 3+ -derived absorption at around 973-975 nm and a dependence of the emission intensity and decay time on the doping level, much different from that of sintered pellets.

Thermoluminescence and optically stimulated luminescence properties of nanocrystalline Er3+ and Yb3+ doped Y3Al5O12 exposed to β-rays

International Nuclear Information System (INIS)

RodrIguez, R A; Rosa, E de la; Salas, P; Melendrez, R; Barboza-Flores, M

2005-01-01

The thermoluminescence (TL) and optically stimulated luminescence (OSL) characterization of Er 3+ and Yb 3+ doped Y 3 Al 5 O 12 nanocrystalline samples prepared by the precipitation process and exposed to β-rays are discussed. The TL as well as the OSL were two orders of magnitude higher in Er 3+ doped than in Yb 3+ specimens. The charge trapping and the radiative thermally stimulated recombination processes in Y 3 Al 5 O 12 : Er 3+ involve four trapping states at 166, 243, 342 and 424 deg. C, but just two trapping levels at 219 and 413 deg. C for Y 3 Al 5 O 12 : Yb 3+ at a heating rate of 10 deg. C s -1 . The photostimulation with 470 nm light causes in both phosphors a radiative recombination of the optically free charge carriers belonging to the same trapping states. The TL and the OSL as a function of radiation dose behaviour were linear in the 10-100 Gy dose range. The results provide evidence of the potential uses of these materials in radiation storage and dosimeter devices

Multimodal emissions from Tb{sup 3+}/Yb{sup 3+} co-doped lithium borate glass: Upconversion, downshifting and quantum cutting

Energy Technology Data Exchange (ETDEWEB)

Bahadur, A.; Yadav, R.S.; Yadav, R.V.; Rai, S.B., E-mail: sbrai49@yahoo.co.in

2017-02-15

This paper reports the optical properties of Tb{sup 3+}/Yb{sup 3+} co-doped lithium borate (LB) glass prepared by melt quench method. The absorption spectrum of the Yb{sup 3+} doped LB glass contains intense NIR band centered at 976 nm due to {sup 2}F{sub 7/2}→{sup 2}F{sub 5/2} transition. The emission spectra of the prepared glasses have been monitored on excitation with 266, 355 and 976 nm. The Yb{sup 3+} doped glass emits a broad NIR band centered at 976 nm whereas the Tb{sup 3+} doped glass gives off visible bands on excitations with 266 and 355 nm. When the Tb{sup 3+} and Yb{sup 3+} ions are co-doped together, the emission intensity in the visible region decreases whereas it increases in the NIR region significantly. The increase in the emission intensity in the NIR region is due to efficient cooperative energy transfer (CET) from Tb{sup 3+} to Yb{sup 3+} ions. The quantum cutting efficiency for Tb{sup 3+}/Yb{sup 3+} co-doped glass has been calculated and compared for 266 and 355 nm excitations. The quantum cutting efficiency is larger for 355 nm excitation (137%). The Tb{sup 3+}/Yb{sup 3+} co-doped LB glass also emits upconverted visible bands on excitation with 976 nm. The mechanisms involved in the energy transfer have been discussed using schematic energy level diagram. The Tb{sup 3+}/Yb{sup 3+} co-doped LB glass may be used in the optical devices and in solar cell for solar spectral conversion and behaves as a multi-modal photo-luminescent material. - Graphical abstract: The Tb{sup 3+}/Yb{sup 3+} co-doped lithium borate (LB) glass prepared by melt quench method emits upconverted visible emissions through upconversion CET from Yb{sup 3+} to Tb{sup 3+} ions and quantum cutting emissions through downconversion CET from Tb{sup 3+} to Yb{sup 3+} ions. Therefore, the Tb{sup 3+}/Yb{sup 3+} co-doped LB glass may find applications in optical devices and solar cell and behaves as a multi-modal photo-luminescent material. - Highlights: • The Tb{sup 3+}/Yb{sup 3

Downconversion in Pr3+–Yb3+ co-doped ZBLA fluoride glasses

International Nuclear Information System (INIS)

Maalej, O.; Boulard, B.; Dieudonné, B.; Ferrari, M.; Dammak, M.; Dammak, M.

2015-01-01

Fluorozirconate ZBLA glasses with molar composition 57ZrF 4 –34BaF 2 –5LaF 3 –4AlF 3 –0.5PrF 3 –xYbF 3 (from x=0 to 10) were synthesized to evaluate the rate of the conversion of visible photons into infrared photons. The emission spectra in the near infrared (NIR) at 950–1100 nm and the luminescence decays in the visible and NIR indicate an energy transfer from Pr 3+ to Yb 3+ upon blue excitation of Pr 3+ at 440 nm. The energy transfer efficiency increases with Yb 3+ concentration to reach 86% with 0.5Pr 3+ –10Yb 3+ co-doping (in mol%). However, the quenching of the Yb 3+ emission strongly reduces the efficiency of the downconversion process: the decay time values decrease from 600 µs (x=0.5 mol%) to 85 µs (x=10 mol%). - Highlights: • We synthesized 0.5Pr 3+ –xYb 3+ co-doped ZBLA glasses (from x=0 to 10 mol %). • Photoluminescence of Yb 3+ was observed at 980 nm under blue excitation. • Time resolved measurements have been performed in the visible and near infrared. • Energy transfer efficiency from Pr 3+ to Yb 3+ reaches 86% in 0.5 Pr 3+ –10Yb 3+ glass

Synthesis and Characterization of Yttria-Stabilized Zirconia Nanoparticles Doped with Ytterbium and Gadolinium: ZrO2 9.5Y2O3 5.6Yb2O3 5.2Gd2O3

Science.gov (United States)

Bahamirian, M.; Hadavi, S. M. M.; Rahimipour, M. R.; Farvizi, M.; Keyvani, A.

2018-06-01

Defect cluster thermal barrier coatings (TBCs) are attractive alternatives to Yttria-stabilized zirconia (YSZ) in advanced applications. In this study, YSZ nanoparticles doped with ytterbium and gadolinium (ZrO2 9.5Y2O3 5.6Yb2O3 5.2Gd2O3 (ZGYbY)) were synthesized through a chemical co-precipitation and calcination method, and characterized by in situ high-temperature X-ray diffraction analysis in the temperature range of 25 °C to 1000 °C (HTK-XRD), thermogravimetric analysis, differential thermal analysis, Fourier transform infrared spectroscopy, Raman spectroscopy, and field emission scanning electron microscopy (FE-SEM). Precise cell parameters of t-prime phase and the best zirconia phase for TBC applications were calculated by Cohen's and Rietveld refinement methods. Optimum crystallization temperature of the precursor powder was found to be 1000 °C. Furthermore, FE-SEM results for the calcined ZGYbY powders indicated orderly particles of uniform shape and size with a small tendency toward agglomeration. Average lattice thermal expansion coefficient in the temperature range of 25 °C to 1000 °C was determined to be 31.71 × 10-6 K-1.

Synthesis and Characterization of Yttria-Stabilized Zirconia Nanoparticles Doped with Ytterbium and Gadolinium: ZrO2 9.5Y2O3 5.6Yb2O3 5.2Gd2O3

Science.gov (United States)

Bahamirian, M.; Hadavi, S. M. M.; Rahimipour, M. R.; Farvizi, M.; Keyvani, A.

2018-03-01

Defect cluster thermal barrier coatings (TBCs) are attractive alternatives to Yttria-stabilized zirconia (YSZ) in advanced applications. In this study, YSZ nanoparticles doped with ytterbium and gadolinium (ZrO2 9.5Y2O3 5.6Yb2O3 5.2Gd2O3 (ZGYbY)) were synthesized through a chemical co-precipitation and calcination method, and characterized by in situ high-temperature X-ray diffraction analysis in the temperature range of 25 °C to 1000 °C (HTK-XRD), thermogravimetric analysis, differential thermal analysis, Fourier transform infrared spectroscopy, Raman spectroscopy, and field emission scanning electron microscopy (FE-SEM). Precise cell parameters of t-prime phase and the best zirconia phase for TBC applications were calculated by Cohen's and Rietveld refinement methods. Optimum crystallization temperature of the precursor powder was found to be 1000 °C. Furthermore, FE-SEM results for the calcined ZGYbY powders indicated orderly particles of uniform shape and size with a small tendency toward agglomeration. Average lattice thermal expansion coefficient in the temperature range of 25 °C to 1000 °C was determined to be 31.71 × 10-6 K-1.

Near infrared emission and multicolor tunability of enhanced upconversion emission from Er{sup 3+}–Yb{sup 3+} co-doped Nb{sub 2}O{sub 5} nanocrystals embedded in silica-based nanocomposite and planar waveguides for photonics

Energy Technology Data Exchange (ETDEWEB)

Aquino, Felipe Thomaz [Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo. Av. Bandeirantes, 3900, CEP 14040-901 Ribeirão Preto, SP (Brazil); Ferrari, Jefferson Luis [Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo. Av. Bandeirantes, 3900, CEP 14040-901 Ribeirão Preto, SP (Brazil); Grupo de Pesquisa em Química de Materiais – (GPQM), Departamento de Ciências Naturais, Universidade Federal de São João Del Rei, Campus Dom Bosco, Praça Dom Helvécio, 74, 36301-160 São João Del Rei, MG (Brazil); Maia, Lauro June Queiroz [Grupo Física de Materiais, Instituto de Física, Universidade Federal de Goiás, Campus II, C.P. 131, CEP 74001-970, Goiânia, GO (Brazil); Ribeiro, Sidney José Lima [Institute of Chemistry- São Paulo State University- UNESP, Araraquara, SP 14800-900 (Brazil); Ferrier, Alban [PSL Research University, Chimie ParisTech - CNRS, Institut de Recherche de Chimie Paris, 75005 Paris (France); Sorbonne Universités, UPMC Univ Paris 06, 75005 Paris (France); and others

2016-02-15

This work reports on the Yb{sup 3+} ion addition effect on the near infrared emission and infrared-to-visible up conversion from planar waveguides based on Er{sup 3+}–Yb{sup 3+} co-doped Nb{sub 2}O{sub 5} nanocrystals embedded in SiO{sub 2}-based nanocomposite prepared by a sol–gel process with controlled crystallization in situ. Planar waveguides and xerogels containing Si/Nb molar ratio of 90:10 up to 50:50 were prepared. Spherical-like orthorhombic or monoclinic Nb{sub 2}O{sub 5} nanocrystals were grown in the amorphous SiO{sub 2}-based host depending on the niobium content and annealing temperature, resulting in transparent glass ceramics. Crystallization process was intensely affected by rare earth content increase. Enhancement and broadening of the NIR emission has been achieved depending on the rare earth content, niobium content and annealing temperature. Effective Yb{sup 3+}→Er{sup 3+} energy transfer and a high-intensity broad band emission in the near infrared region assigned to the Er{sup 3+} ions {sup 4}I{sub 13/2}→{sup 4}I{sub 15/2} transition, and longer {sup 4}I{sub 13/2} lifetimes were observed for samples containing orthorhombic Nb{sub 2}O{sub 5} nanocrystals. Intense green and red emissions were registered for all Er{sup 3+}–Yb{sup 3+} co-doped waveguides under 980 nm excitation, assigned to {sup 2}H{sub 11/2}→{sup 4}I{sub 15/2} (525 nm),{sup 4}S{sub 3/2}→{sup 4}I{sub 15/2} (545nm) and {sup 4}F{sub 9/2}→{sup 4}I{sub 15/2} (670 nm) transitions, respectively. Different relative green and red intensities emissions were observed, depending upon niobium oxide content and the laser power. Upconversion dynamics were determined by the photons number, evidencing that ESA or ETU mechanisms are probably occurring. The 1931 CIE chromaticity diagrams indicated interesting color tunability based on the waveguides composition and pump power. The nanocomposite waveguides are promising materials for photonic applications as optical amplifiers and

Ag2O dependent up-conversion luminescence properties in Tm3+/Er3+/Yb3+ co-doped oxyfluorogermanate glasses

International Nuclear Information System (INIS)

Hu, Yuebo; Qiu, Jianbei; Song, Zhiguo; Zhou, Dacheng

2014-01-01

Up-conversion (UC) luminescence properties of Ag/Tm 3+ /Er 3+ /Yb 3+ co-doped oxyfluorogermanate glasses have been studied to assess the effective role of silver nanoparticles as a sensitizer for Tm 3+ and Er 3+ ions. The X-ray diffraction patterns obtained in this work do not reveal any crystalline phase in the glass. However, the absorption spectra reveal that surface plasmons resonance band of Ag undergoes a distinct split with two maxima and a very broad absorption peak with a background that extends toward the near infrared (NIR) with the increasing of Ag 2 O added concentration. Transmission electron microscope images confirm that silver nanoparticles have been precipitated from matrix glasses and show their distribution, size, and shapes. In addition, changes in UC luminescence intensity of four emission bands 476, 524, 546, and 658 nm corresponding to 1 G 4 → 3 H 6 (Tm 3+ ), ( 2 H 11/2 , 4 S 3/2 ) → 4 I 15/2 (Er 3+ ), and 4 F 9/2 → 4 I 15/2 (Er 3+ ) transitions, respectively, as a function of silver addition to the base composition have been measured under 980 nm excitation. It is confirmed that Ag 2 O added concentration plays an important role in increasing the UC luminescence intensity; however, further increase in Ag 2 O added concentration reduces the intensity

Method for fitting crystal field parameters and the energy level fitting for Yb3+ in crystal SC2O3

International Nuclear Information System (INIS)

Qing-Li, Zhang; Kai-Jie, Ning; Jin, Xiao; Li-Hua, Ding; Wen-Long, Zhou; Wen-Peng, Liu; Shao-Tang, Yin; Hai-He, Jiang

2010-01-01

A method to compute the numerical derivative of eigenvalues of parameterized crystal field Hamiltonian matrix is given, based on the numerical derivatives the general iteration methods such as Levenberg–Marquardt, Newton method, and so on, can be used to solve crystal field parameters by fitting to experimental energy levels. With the numerical eigenvalue derivative, a detailed iteration algorithm to compute crystal field parameters by fitting experimental energy levels has also been described. This method is used to compute the crystal parameters of Yb 3+ in Sc 2 O 3 crystal, which is prepared by a co-precipitation method and whose structure was refined by Rietveld method. By fitting on the parameters of a simple overlap model of crystal field, the results show that the new method can fit the crystal field energy splitting with fast convergence and good stability. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Continuous wave and tunable laser operation of Yb3+ in disordered NaLa(MoO4)2

Science.gov (United States)

Rico, M.; Liu, J.; Cano-Torres, J. M.; García-Cortés, A.; Cascales, C.; Zaldo, C.; Griebner, U.; Petrov, V.

2005-09-01

Continuous-wave Yb3+ laser operation is studied in single crystals of disordered NaLa(MoO4)2 at room temperature. The sample used was grown by the Czochralski technique and incorporates an Yb ion density of 3.1×1020 cm-3. The effect of the Yb concentration on some of the crystal properties is described as well as the spectroscopic Yb3+ properties at 5 K. Maximum slope efficiencies of about 40% for π and 38% for σ polarization were obtained under Ti:sapphire laser pumping near 976 nm, respectively. The maximum output power for the π polarization was 400 mW at 1039.5 nm, the threshold in this case amounted to 240 mW (absorbed pump power). The laser emission was tunable between 1016 and 1064 nm with a Lyot filter. Lasing was also realized by pumping with a fiber-coupled diode laser module. Maximum output power of 900 mW at 1035 nm was achieved in this case for the π polarization and the threshold was 280 mW. The results, in terms of output power and tunability, are superior in comparison to all previous reports on Yb-doped disordered double tungstate or molybdate crystals and represent a significant improvement in comparison to earlier experiments with low-doped Yb:NaLa(MoO4)2.

Formation of Deep Electron Trap by Yb3+ Codoping Leads into Super-Long Persistent Luminescence in Ce3+-doped Yttrium Aluminum Gallium Garnet Phosphors.

Science.gov (United States)

Ueda, Jumpei; Miyano, Shun; Tanabe, Setsuhisa

2018-05-23

The Y 3 Al 2 Ga 3 O 12 :Ce 3+ -Cr 3+ compound is one of the brightest persistent phosphors, but its persistent luminescence (PersL) duration is not so long due to the relatively shallow Cr 3+ electron trap. Comparing the vacuum referred binding energy of the electron trapping state by Cr 3+ and those by lanthanide ions, we selected Yb 3+ as a deeper electron trapping center. The Y 3 Al 2 Ga 3 O 12 :Ce 3+ -Yb 3+ phosphors show Ce 3+ :5d→4f green persistent luminescence after ceasing blue light excitation. The formation of Yb 2+ was confirmed by the increased intensity of absorption at 585 nm during the charging process. This result indicates that the Yb 3+ ions act as electron traps by capturing an electron. From the thermoluminescence glow curves, it was found the Yb 3+ trap makes much deeper electron trap with 1.01 eV depth than the Cr 3+ electron trap with 0.81 eV depth. This deeper Yb 3+ trap provides much slower detrapping rate of filled electron traps than the Cr 3+ -codoped persistent phosphor. In addition, by preparing transparent ceramics and optimizing Ce 3+ and Yb 3+ concentrations, the Y 3 Al 2 Ga 3 O 12 :Ce 3+ (0.2%)-Yb 3+ (0.1%) as-made transparent ceramic phosphor showed super long persistent luminescence for over 138.8 hours after ceasing blue light charging.

Growth, characterization, and waveguide lasing of Yb3+, Lu3+, Gd3+ co-doped KY(WO4)2 thin layers

NARCIS (Netherlands)

Aravazhi, S.; Geskus, D.; Günther, D.; Worhoff, Kerstin; Pollnau, Markus

2009-01-01

Monoclinic crystals of KY(WO4)2 (KYW) doped with different rare-earth ions are among the highly promising materials for building compact solid-state lasers. We report the liquid phase epitaxy (LPE) growth of 3-5 µm thick KYW:Gd3+, Lu3+, Yb3+ layers for Yb3+ concentrations of 1.2, 1.7, and 2.4 mol%

Broadband down-conversion based near infrared quantum cutting in Eu{sup 2+}–Yb{sup 3+} co-doped SrAl{sub 2}O{sub 4} for crystalline silicon solar cells

Energy Technology Data Exchange (ETDEWEB)

Tai, Yuping, E-mail: yupingtai@126.com [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry (Ministry of Education), College of Chemistry & Materials Science, Northwest University, Xi’an 710069 (China); Zheng, Guojun, E-mail: zhengguojun88@126.com [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry (Ministry of Education), College of Chemistry & Materials Science, Northwest University, Xi’an 710069 (China); Wang, Hui, E-mail: huiwang@nwu.edu.cn [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry (Ministry of Education), College of Chemistry & Materials Science, Northwest University, Xi’an 710069 (China); National Key Laboratory of Photoelectric Technology and Functional Materials Culture Base, National Photoelectric Technology and Functional Materials & Application of International Science and Technology Cooperation Base, Institute of Photonics & Photon-Technology, Northwest University, Xi' an 710069 (China); Bai, Jintao, E-mail: baijt@nwu.edu.cn [National Key Laboratory of Photoelectric Technology and Functional Materials Culture Base, National Photoelectric Technology and Functional Materials & Application of International Science and Technology Cooperation Base, Institute of Photonics & Photon-Technology, Northwest University, Xi' an 710069 (China)

2015-03-15

Near infrared (NIR) quantum cutting involving the down conversion of an absorbed visible photon to emission of two NIR photons was achieved in SrAl{sub 2}O{sub 4}:0.01Eu{sup 2+}, xYb{sup 3+} (x=0, 1, 2, 5, 10, 20, 30 mol%) samples. The photoluminescence properties of samples in visible and NIR regions were measured to verify the energy transfer (ET) from Eu{sup 2+} to Yb{sup 3+}. The results demonstrated that Eu{sup 2+} was an efficient sensitizer for Yb{sup 3+} in the SrAl{sub 2}O{sub 4} host lattice. According to Gaussian fitting analysis and temperature-dependent luminescence experiments, the conclusion was drawn that the cooperative energy transfer (CET) process dominated the ET process and the influence of charge transfer state (CTS) of Yb{sup 3+} could be negligible. As a result, the high energy transfer efficiency (ETE) and quantum yield (QY) have been acquired, the maximum value approached 73.68% and 147.36%, respectively. Therefore, this down-conversion material has potential application in crystalline silicon solar cells to improve conversion efficiency. - Graphical abstract: Near infrared quantum cutting was achieved in Eu{sup 2+}–Yb{sup 3+} co-doped SrAl{sub 2}O{sub 4} samples. The cooperative energy transfer process dominated energy transfer process and high energy transfer efficiency was acquired. - Highlights: • The absorption spectrum of Eu{sup 2+} ion is strong in intensity and broad in bandwidth. • The spectra of Eu{sup 2+} in SrAl{sub 2}O{sub 4} lies in the strongest region of solar spectrum. • The cooperative energy transfer (CET) dominated the energy transfer process. • The domination of CET is confirmed by experimental analysis. • SrAl{sub 2}O{sub 4}:Eu{sup 2+},Yb{sup 3+} show high energy transfer efficiency and long lifetime.

Optical properties and radiation response of Ce3+-doped GdScO3 crystals

International Nuclear Information System (INIS)

Yamaji, Akihiro; Fujimoto, Yutaka; Futami, Yoshisuke; Yokota, Yuui; Kurosawa, Shunsuke; Kochurikhin, Vladimir; Yanagida, Takayuki; Yoshikawa, Akira

2012-01-01

10%-Ce doped GdScO 3 perovskite type single crystal was grown by the Czochralski process. The Ce concentration in the crystal was measured. No impurity phases were observed by powder X-ray diffraction analysis. We evaluated the optical and radiation properties of the grown crystal. Ce:GdScO 3 crystal showed photo- and radio-luminescence peaks due to Ce 3+ of 5d-4f transition and colour centre. The photoluminescence decay time was sub-ns order. The relative light yield under 5.5 MeV alpha-ray excitation was calculated to be approximately 9% of BGO. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Improving the photoluminescence response of Er-Tm: Al2O3 films by Yb codoping

International Nuclear Information System (INIS)

Xiao Zhisong; Serna, R.; Afonso, C.N.; Cheng Guoan; Vickridge, I.

2007-01-01

Amorphous Al 2 O 3 films doped with Er, Tm and Yb have been prepared by pulsed laser deposition. A broadband emission in the range 1400-1700 nm with two peaks around 1540 and 1640 nm has been observed, both in the Er-Tm and Er-Tm-Yb codoped films. The Tm-related photoluminescence (PL) intensity at 1640 nm is enhanced when codoping with Yb thus suggesting the existence of multiple energy transfer processes from Yb to Er and Er to Tm. The Er-Tm-Yb codoped film exhibits a broadband emission with a full-width half-maximum of 184 nm similar to that of the film codoped with Tm and Er but having higher Tm to Er concentration ratio and higher PL lifetime values

Frequency upconversion fluorescence studies of Er{sup 3+}/Yb{sup 3+}-codoped KNbO{sub 3} phosphors

Energy Technology Data Exchange (ETDEWEB)

Balakrishnaiah, R. [Department of Electronic Materials Engineering, Silla University, Busan 617-736 (Korea, Republic of); Department of Physics, Changwon National University, Changwon 641-773 (Korea, Republic of); Kim, Dong Woo [Department of Electronic Materials Engineering, Silla University, Busan 617-736 (Korea, Republic of); Yi, Soung Soo, E-mail: ssyi@silla.ac.k [Department of Electronic Materials Engineering, Silla University, Busan 617-736 (Korea, Republic of); Kim, Kwang Duk; Kim, Sung Hoon [Department of Engineering in Energy and Applied Chemistry, Silla University, Busan 617-736 (Korea, Republic of); Jang, Kiwan; Lee, Ho Sueb [Department of Physics, Changwon National University, Changwon 641-773 (Korea, Republic of); Jeong, Jung Hyun [Department of Physics, Pukyong National University, Busan 608-737 (Korea, Republic of)

2009-05-29

Different concentrations of Er{sup 3+} and Yb{sup 3+} ions-doped potassium niobate (K{sub 0.9}NbO{sub 3}:Yb{sub (x)}Er{sub (0.1-x)} for x = 0, 0.01, 0.05, 0.09 and 0.1) polycrystalline powder phosphors were prepared by the conventional solid state reaction method and were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. Energy transfer and upconversion fluorescence properties of the Yb{sup 3+} and Er{sup 3+}-codoped phosphors have been discussed. The XRD data has shown mono-phase for pure KNbO{sub 3} while the doped samples represented additional phase formation. The SEM micrographs represented the rectangular crystal growth habit for the KNbO{sub 3} phosphors when doped with 0.1 mol of Er{sup 3+} ions. An intense green emission at 557 nm along with a red emission at 674 nm was observed when the doped samples were excited with 975 nm IR radiation. The upconversion mechanism has been discussed based on the excited state absorption and energy transfer mechanisms.

Passive mode locking of 2.09 microm Cr,Tm,Ho:Y3Sc2Al3O12 laser using PbS quantum-dot-doped glass.

Science.gov (United States)

Denisov, Igor A; Skoptsov, Nikolai A; Gaponenko, Maxim S; Malyarevich, Alexander M; Yumashev, Konstantin V; Lipovskii, Andrei A

2009-11-01

Passive Q-switched mode locking of a 2.09 microm flashlamp-pumped Cr(3+),Tm(3+),Ho(3+):Y(3)Sc(2)Al(3)O(12) laser by use of a phosphate glass doped with PbS quantum dots of 5 nm in radius was demonstrated. Mode-locked pulses of 290 ps in duration and up to 0.5 mJ in energy were registered.

Creep properties and precipitate evolution in Al-Li alloys microalloyed with Sc and Yb

Energy Technology Data Exchange (ETDEWEB)

Krug, Matthew E. [Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Evanston, IL 60208 (United States); Seidman, David N. [Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Evanston, IL 60208 (United States); Northwestern Center for Atom Probe Tomography, Northwestern University, 2220 Campus Drive, Evanston, IL 60208 (United States); Dunand, David C., E-mail: dunand@northwestern.edu [Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Evanston, IL 60208 (United States)

2012-07-30

Highlights: Black-Right-Pointing-Pointer We examine the creep behavior of Al-alloys with Li and rare earth element additions. Black-Right-Pointing-Pointer These alloys exhibit threshold stresses below which no measurable creep occurs. Black-Right-Pointing-Pointer Larger precipitate size and lattice parameter mismatch increase creep resistance. Black-Right-Pointing-Pointer A simple parameter describes the threshold stress behavior in ternary Al-Sc-X alloys. Black-Right-Pointing-Pointer The findings are explained by a recent model of dislocation-precipitate interactions. - Abstract: A dilute Al-Sc alloy (Al-0.12 Sc, at.%, Al-Sc), its counterpart with a Li addition (Al-2.9 Li-0.11 Sc, at.%, Al-Li-Sc), as well as a quaternary alloy (Al-5.53 Li-0.048 Sc-0.009 Yb, at.%, Al-Li-Sc-Yb) were isothermally aged at 325 Degree-Sign C, and in some cases isochronally aged to 450 Degree-Sign C. As the {alpha} Prime -Al{sub 3}(Li,Sc) and Al{sub 3}(Li,Sc,Yb) precipitates, with L1{sub 2} structure, coarsen in the two Li-containing alloys, their Li and Yb concentrations decrease and their Sc concentration increases. A significant interfacial excess of Li also segregates at the {alpha}-Al matrix/{alpha} Prime -Al{sub 3}Sc(Li,Sc,Yb) precipitate interface: 5.99 {+-} 0.05 atoms nm{sup -2} in Al-Li-Sc and 13.2 {+-} 0.4 atoms nm{sup -2} in Al-Li-Sc-Yb after aging isochronally to 450 Degree-Sign C. During compression creep at 300 Degree-Sign C, the aged alloys exhibit threshold stresses between 8 and 22 MPa. A recent threshold stress model based on elastic interactions between dislocations and precipitates predicts correctly that Li additions in the Al-Li-Sc alloy reduce the threshold stress, while Yb in the Al-Li-Sc-Yb alloy increases it. The model is also in agreement with the threshold stresses of all Al-Sc-X alloys published to date.

Spectroscopic investigations of OH- influence on near-infrared fluorescence quenching of Yb3+/Tm3+ co-doped sodium-metaphosphate glasses

International Nuclear Information System (INIS)

Terra, I.A.A.; Camargo, A.S.S. de; Terrile, M.C.; Nunes, L.A.O.

2008-01-01

Energy transfer processes were studied in two sets of Yb 3+ and Tm 3+ co-doped sodium-metaphosphate glasses, prepared in air and nitrogen atmospheres. Using Foerster, Dexter, and Miyakawa theoretical models, the energy transfer parameters were calculated. The main ion-ion energy transfer processes analyzed were energy migration among Yb 3+ ions, cross-relaxations between Yb 3+ and Tm 3+ ions, and interactions with OH - radicals. The results indicated that Yb→Tm energy transfer favors 1.8 μm emissions, and there is no evidence of concentration quenching up to 2% Tm 2 O 3 doping. As expected, samples prepared in nitrogen atmosphere present higher fluorescence quantum efficiency than those prepared in air, and this feature is specially noted in the near-infrared region, where the interaction with the OH - radicals is more pronounced

Investigation of Upconversion, downshifting and quantum –cutting behavior of Eu3+, Yb3+, Bi3+ co-doped LaNbO4 phosphor as a spectral conversion material

Science.gov (United States)

Dwivedi, A.; Mishra, K.; Rai, S. B.

2018-06-01

This work presents the spectral conversion characteristics [upconversion (UC), downshifting (DS) and quantum–cutting (QC) optical processes] of Eu3+, Yb3+ and Bi3+ co-doped LaNbO4 (LBO) phosphor samples synthesized by solid state reaction technique. The crystal structure and the pure phase formation have been confirmed by x-ray diffraction (XRD) measurements. The surface morphology and particle size are studied by scanning electron microscopy (SEM). The rarely observed intense red UC emission from Eu3+ ion has been successfully obtained in Eu3+/Yb3+ co-doped LaNbO4 phosphor (on excitation with 980 nm) by optimizing the concentrations of Eu3+ and Yb3+ ions. The downshifting (DS) behavior has been studied by photoluminescence (PL) measurements on excitation with 265 nm wavelength from a Xe lamp source. A broad blue emission in the region 300–550 nm with its maximum ∼415 nm due to charge transfer band (CTB) of the host and large number of sharp peaks due to f-f transitions of Eu3+ ion have been observed. The energy transfer has been observed from (NbO4)3‑ to Eu3+ ion and the fluorescence emission has been optimized by varying the concentration of Eu3+ ion. An intense red emission has also been observed corresponding to 5D0 → 7F2 transition of Eu3+ ion at 611 nm in LBO: 0.09Eu3+ phosphor on excitation with 394 nm. The luminescence properties of Eu3+ ion are enhanced further through the sensitization effect of Bi3+ ion. The near infra-red (NIR) quantum cutting (QC) behavior due to Yb3+ ion has been monitored on excitation with 265 as well as 394 nm. The NIR QC is observed due to 2F5/2 → 2F7/2 transition of Yb3+ ion via co-operative energy transfer (CET) process from (NbO4)3‑ as well as Eu3+ ions to Yb3+ ion. This multimodal behavior (UC, DS and QC) makes this a promising phosphor material for multi-purpose spectral converter.

Structure-Dependent Spectroscopic Properties of Yb3+-Doped Phosphosilicate Glasses Modified by SiO₂.

Science.gov (United States)

Wang, Ling; Zeng, Huidan; Yang, Bin; Ye, Feng; Chen, Jianding; Chen, Guorong; Smith, Andew T; Sun, Luyi

2017-02-28

Yb 3+ -doped phosphate glasses containing different amounts of SiO₂ were successfully synthesized by the conventional melt-quenching method. The influence mechanism of SiO₂ on the structural and spectroscopic properties was investigated systematically using the micro-Raman technique. It was worth noting that the glass with 26.7 mol % SiO₂ possessed the longest fluorescence lifetime (1.51 ms), the highest gain coefficient (1.10 ms·pm²), the maximum Stark splitting manifold of ²F 7/2 level (781 cm -1 ), and the largest scalar crystal-field N J and Yb 3+ asymmetry degree. Micro-Raman spectra revealed that introducing SiO₂ promoted the formation of P=O linkages, but broke the P=O linkages when the SiO₂ content was greater than 26.7 mol %. Based on the previous 29 Si MAS NMR experimental results, these findings further demonstrated that the formation of [SiO₆] may significantly affect the formation of P=O linkages, and thus influences the spectroscopic properties of the glass. These results indicate that phosphosilicate glasses may have potential applications as a Yb 3+ -doped gain medium for solid-state lasers and optical fiber amplifiers.

Microstructural and electrical characteristics of rare earth oxides doped ZnO varistor films

Science.gov (United States)

Jiao, Lei; Mei, Yunzhu; Xu, Dong; Zhong, Sujuan; Ma, Jia; Zhang, Lei; Bao, Li

2018-02-01

ZnO-Bi2O3 varistor films doped with two kinds of rare earth element oxides (Lu2O3 and Yb2O3) were prepared by the sol-gel method. The effects of Lu2O3/Yb2O3 doping on the microstructure and electrical characteristics of ZnO-Bi2O3 varistor films were investigated. All samples show a homogenized morphology and an improved nonlinear relationship between the electric field (E) and current density (I). Both Yb2O3 and Lu2O3 doping can decrease the grain size of ZnO-Bi2O3 varistor films and improve the electrical properties, which have a positive effect on the development of ZnO varistor ceramics. Yb2O3 doping significantly increases the dielectric constant at low frequency. 0.2 mol. % Yb2O3 doped ZnO-Bi2O3 varistor films exhibit the highest nonlinear coefficient (2.5) and the lowest leakage current (328 μA) among Lu2O3/Yb2O3 doped ZnO-Bi2O3 varistor films. Similarly, 0.1 mol. % Lu2O3 doping increases the nonlinear coefficient to 1.9 and decrease the leakage current to 462 μA.

Raman and Fluorescence Spectroscopy of CeO2, Er2O3, Nd2O3, Tm2O3, Yb2O3, La2O3, and Tb4O7

Directory of Open Access Journals (Sweden)

Jianlan Cui

2015-01-01

Full Text Available To better understand and ascertain the mechanisms of flotation reagent interaction with rare earth (RE minerals, it is necessary to determine the physical and chemical properties of the constituent components. Seven rare earth oxides (CeO2, Er2O3, Nd2O3, Tm2O3, Yb2O3, La2O3, and Tb4O7 that cover the rare earth elements (REEs from light to heavy REEs have been investigated using Raman spectroscopy. Multiple laser sources (wavelengths of 325 nm, 442 nm, 514 nm, and 632.8 nm for the Raman shift ranges from 100 cm−1 to 5000 cm−1 of these excitations were used for each individual rare earth oxide. Raman shifts and fluorescence emission have been identified. Theoretical energy levels for Er, Nd, and Yb were used for the interpretation of fluorescence emission. The experimental results showed good agreement with the theoretical calculation for Er2O3 and Nd2O3. Additional fluorescence emission was observed with Yb2O3 that did not fit the reported energy level diagram. Tb4O7 was observed undergoing laser induced changes during examination.

Enhanced ~2.7 µm emission investigation of Er{sup 3+}:{sup 4}I{sub 11/2}→{sup 4}I{sub 13/2} transition in Yb,Er,Pr:SrLaGa{sub 3}O{sub 7} crystal

Energy Technology Data Exchange (ETDEWEB)

Wang, Yan [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Zhang, Baotong [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); College of Materials Science and Engineering, Fujian Normal University, Fuzhou, Fujian 350007 (China); Li, Jianfu; Zhu, Zhaojie; You, Zhenyu [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Tu, Chaoyang, E-mail: tcy@fjirsm.ac.cn [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China)

2017-03-15

The bulk crystal of 5at% Yb{sup 3+}, 20 at% Er{sup 3+} and 0.2 at% Pr{sup 3+} triply doped SrLaGa{sub 3}O{sub 7} (abbr. as Yb,Er,Pr:SLGO) was grown by the Czochralski method. The effects of co-dopant Yb{sup 3+} and Pr{sup 3+} on the spectroscopic properties and the mutual energy transfer mechanism were investigated, via the measurements of its absorption, near-infrared and mid-infrared fluorescence spectra, as well as the fluorescence decay curves of Er{sup 3+}:{sup 4}I{sub 13/2} and {sup 4}I{sub 11/2} levels at room temperature. As compared with 20at% Er{sup 3+} singly doped SrLaGa{sub 3}O{sub 7} crystal, ~2.7 µm emission intensity corresponding to Er{sup 3+}:{sup 4}I{sub 11/2}→{sup 4}I{sub 13/2} transition is enhanced greatly in the Yb,Er,Pr:SLGO crystal. Spectral analyses indicate that the sensitization of Yb{sup 3+} to Er{sup 3+} improves the ~2.7 µm emission in Yb,Er,Pr:SLGO crystal, meanwhile, the depopulation of Pr{sup 3+} from Er{sup 3+} decreases the ~1.5 µm emission and inhibits the self-termination effect. The energy transfer efficiencies of Yb{sup 3+}→Er{sup 3+} (ET1), Er{sup 3+}→Pr{sup 3+} (ET2) and Er{sup 3+}→Pr{sup 3+} (ET3) were estimated and discussed. The above results conclude that Yb,Er,Pr:SLGO crystal is a good candidate for LD pumped mid-infrared laser. - Graphical abstract: As compared with Er: SrLaGa{sub 3}O{sub 7} crystal, ~2.7 µm MIR emissions corresponding to Er{sup 3+}:{sup 4}I{sub 11/2}→{sup 4}I{sub 13/2} transition were enhanced in Yb{sup 3+}, Er{sup 3+} and Pr{sup 3+} triply doped SrLaGa{sub 3}O{sub 7} crystal owing to the sensitization of co-dopant Yb{sup 3+} via ET1, at the same time, ~1.5 µm NIR emissions were weakened owing to the depopulation of co-dopant Pr{sup 3+} via ET3.

Synthesis–property relationship in thermoelectric Sr 1− x Yb x TiO 3− δ ceramics

KAUST Repository

Bhattacharya, S

2014-08-22

The electronic transport properties of a series of Sr1-xYbxTiO3-delta (x = 0.05, 0.1) ceramics are investigated as a function of solid-state reaction (SSR) parameters, specifically calcination steps. It was found that the electrical conductivity (sigma) increases almost by a factor of 6, through the optimization of SSR parameters. The enhancement in the electrical conductivity leads to an enhancement in the thermoelectric power factor by a factor of 3. In addition, the lattice thermal conductivity (k(L)) of the Sr1-xYbxTiO3-delta ceramics is suppressed with increasing Yb-doping, supposedly due to heavier atomic mass of Yb substituted at the Sr site and a smaller ionic radii of Yb+3 with respect to Sr+2 ions. However, our model calculations indicate that strain-field effect, which occurs due to the difference in ionic radii, is the more prominent phonon scattering mechanism in the Yb-doped SrTiO3. This work is an extension of our previous study on the underlying phonon scattering mechanisms in the Y-doped SrTiO3, which would provide new insight into thermal transport in doped SrTiO3 and could be used as a guideline for more effective material synthesis.

Ionic conductivity ageing behaviour of 10 mol.% Sc2O3–1 mol.% CeO2–ZrO2 ceramics

DEFF Research Database (Denmark)

Omar, Shobit; Bonanos, Nikolaos

2010-01-01

The long-term ionic conductivity behaviour of samples of zirconia co-doped with 10 mol.% of Sc2O3 and 1 mol.% CeO2 is evaluated in oxidizing and reducing atmospheres at 600 °C. After 3,000 h, the sample kept in reducing atmospheres exhibits 20% loss in the ionic conductivity, while the sample kep...

Synthesis and characterization of Nd3+: Yb3+ co-doped near infrared sensitive fluorapatite nanoparticles as a bioimaging probe

Science.gov (United States)

Karthi, S.; Kumar, G. A.; Sardar, D. K.; Santhosh, C.; Girija, E. K.

2018-03-01

Trivalent Nd and Yb co-doped rod shaped hexagonal phase fluorapatite (FAP) nanoparticles of length and width about 32 and 13 nm, respectively were prepared by hydrothermal method and investigated the ability for 980 nm emission via Nd3+ → Yb3+ energy transfer with the objective of utilizing them in biomedical imaging. Nd3+ → Yb3+ energy transfer in FAP was studied as a function of both Nd3+ and Yb3+ concentrations and found that when Yb3+ concentration was 10 mol% the FAP phase has partially turned in to YbPO4 phase. The Yb3+ emission intensity at 980 nm significantly increased up to 5 mol% Yb3+ doping and then reduced drastically for further increase in its concentration. Nd3+ →Yb3+ energy transfer rates were evaluated from the decay curves and found that a transfer rate of 71% for 2 mol% Nd3+ co-doped with 5 mol% Yb3+. The cytocompatibility test with fibroblast like cells using MTT assay revealed that the nanoparticles are compatible with the cells.

Nd3+-doped TeO2-Bi2O3-ZnO transparent glass ceramics for laser application at 1.06 μm

Science.gov (United States)

Hu, Xiaolin; Luo, Zhiwei; Liu, Taoyong; Lu, Anxian

2017-04-01

The high crystallinity transparent glass ceramics based on Nd3+-doped 70TeO2-15Bi2O3-15ZnO (TBZ) compositions were successfully prepared by two-step heat treatment process. The effects of Nd2O3 content on the thermal, structural, mechanical, and optical properties of TBZ glass ceramics were studied. The incorporation of Nd2O3 enhanced the crystallization tendency in the matrix glass composition. The crystal phase and morphology of Bi2Te4O11 in the glass ceramics were confirmed by X-ray diffraction and field emission scanning electron microscopy. Due to precipitate more crystal phase, the hardness values increased from 3.21 to 3.66 GPa. Eight absorption peaks were observed from 400 to 900 nm and three emission bands appeared in the range of 850-1400 nm. With the increasing of Nd2O3 content from 0.5 to 2.5 wt%, the intensity of absorption peaks enhanced and the emission intensity increased up to 1.0 wt% and then fell down for further dopant concentration. The fluorescence decay lifetime decreased rapidly starting from 1.5 wt% Nd2O3 content due to the obvious energy migration among Nd3+. According to the extreme strong emission band around 1062 nm and the optimum Nd2O3 content (1.0 wt%), N10 glass ceramic was considered as a potential material for 1.06 μm laser applications.

Yb3+ sensitized Tm3+ upconversion in tellurite lead oxide glass.

Science.gov (United States)

Mohanty, Deepak Kumar; Rai, Vineet Kumar; Dwivedi, Y

2012-04-01

Triply ionized thulium/thulium--ytterbium doped/codoped TeO2-Pb3O4 (TPO) glasses have been fabricated by classical quenching method. The upconversion emission spectra in the Tm3+/Tm3+-Yb3+ doped/codoped glasses upon excitation with a diode laser lasing at ∼980 nm has been studied. Effect of the addition of the Yb3+ on the upconversion emission intensity in the visible and near infrared regions of the Tm3+ doped in TPO glass has been studied and the processes involved explored. Copyright © 2011 Elsevier B.V. All rights reserved.

Polarized spectroscopic properties of Er3+:Gd2SiO5 crystal and evaluation of Er3+:Yb3+:Gd2SiO5 crystal as a 1.55 μm laser medium

International Nuclear Information System (INIS)

Wang, H.; Huang, J.H.; Gong, X.H.; Chen, Y.J.; Lin, Y.F.; Luo, Z.D.; Huang, Y.D.

2016-01-01

An Er 3+ -doped Gd 2 SiO 5 single crystal with high optical quality has been grown by the Czochralski method. Polarized absorption and fluorescence spectra and fluorescence lifetime of the crystal were measured at room temperature. Intensity parameters, spontaneous emission probabilities, fluorescence branching ratios, and radiative lifetimes were estimated on the basis of the Judd–Ofelt theory. Besides, potentiality of 1.55 μm laser emission in an Er 3+ –Yb 3+ co-doped Gd 2 SiO 5 crystal was evaluated.

Upconversion dynamics in Yb3+-Ho3+-doped fluoroindate glasses

International Nuclear Information System (INIS)

Martin, I.R.; Rodriguez, V.D.; Lavin, V.; Rodriguez-Mendoza, U.R.

1998-01-01

The mechanisms and dynamics of the upconversion emissions in Yb 3+ -Ho 3+ -doped fluoroindate glasses by exciting at 975 nm have been analysed. The upconversion efficiencies have been measured as a function of temperature in the range from 12 to 295 K. The temporal evolution of the 545- and 650-nm upconversion emissions obtained under flash excitation at 975 nm in codoped samples with 2.25 mol.% of Yb 3+ and 0.75 mol.% of Ho 3+ cannot be described using the energy migration model. This indicates that at this concentration of Yb 3+ the rapid migration regimen between these ions has not been reached. A model is proposed in order to explain the temporal evolution of these emissions taking into account energy migration between donors and backtransfer processes. (orig.)

Spectroscopy of Yb-doped tungsten-tellurite glass and assessment of its lasing properties

Science.gov (United States)

Merzliakov, M. A.; Kouhar, V. V.; Malashkevich, G. E.; Pestryakov, E. V.

2018-01-01

Glasses of the TeO2-WO3-Yb2O3 system are synthesized for wide range of Yb3+ concentrations of up to 6.0 × 1021 ions/cm3. The spectral-luminescent properties of lightly doped samples are investigated at room temperature and at the boiling point of liquid nitrogen. The energies of the Stark levels of the ground and excited states of Yb3+ ions incorporated into tungsten-tellurite glass are determined by analyzing the low-temperature spectra. The absorption, emission, and gain cross section spectra are obtained. The excess of the measured fluorescence decay time over the radiative lifetime ∼0.3 ms derived from the absorption spectra is attributed to the reabsorption effect in bulk samples. Measurements of lightly doped glass powder in the immersion liquid are made to reduce the effect of reabsorption. The fluorescence decay time of the powder is very close to the calculated radiative lifetime. Compared with phosphate, silicate, and other Yb3+-doped glasses, the tungsten-tellurite glass has a promising potential as a gain medium for lasers and amplifiers.

Thermal effects on light emission in Yb3+ -sensitized rare-earth doped optical glasses

International Nuclear Information System (INIS)

Gouveia, E.A.; Araujo, M.T. de; Gouveia-Neto, A.S.

2001-01-01

The temperature effect upon infrared-to-visible frequency upconversion fluorescence emission in off-resonance infrared excited Yb 3+ -sensitized rare-earth doped optical glasses is theoretically and experimentally investigated. We have examined samples of Er3+/Yb 3+ -codoped Ga 2 S 3 :La 2 O 3 chalcogenide glasses and germanosilicate optical fibers, and Ga2O3:La 2 O 3 chalcogenide and fluoroindate glasses codoped with Pr 3+ /Yb 3+ , excited off-resonance at 1.064μm. The experimental results revealed thermal induced enhancement in the visible upconversion emission intensity as the samples temperatures were increased within the range of 20 deg C to 260 deg C. The fluorescence emission enhancement is attributed to the temperature dependent multiphonon-assisted anti-Stokes excitation process of the ytterbium-sensitizer. A theoretical approach that takes into account a sensitizer temperature dependent effective absorption cross section, which depends upon the phonon occupation number in the host matrices, has proven to agree very well with the experimental data. As beneficial applications of the thermal enhancement, a temperature tunable amplifier and a fiber laser with improved power performance are presented. (author)

Polarized spectra calculation and continuous wave laser operation of Yb-doped disordered Ca3La2(BO3)4 crystal

Science.gov (United States)

Wang, Yeqing; Chen, Aixi; You, Zhenyu; Tu, Chaoyang

2015-12-01

A notable disorder crystal Yb:Ca3La2(BO3)4 crystal with Yb3+ ion doping concentration of 10 at.% was grown by the Czochralski method. The polarized absorption, polarized emission, and polarized gain cross sections were systematically calculated. The laser operations were investigated with Yb:Ca3La2(BO3)4 crystals cut along the a, b, and c crystallographic axes. The highest output power of 3.88 W was obtained by using the b-cut Yb:Ca3La2(BO3)4 crystal, with a slope efficiency of 62%. Additionally, it was confirmed that the output laser spectra were largely dependent on the output coupler.

Polarized spectra calculation and continuous wave laser operation of Yb-doped disordered Ca3La2(BO3)4 crystal

International Nuclear Information System (INIS)

Wang, Yeqing; Chen, Aixi; You, Zhenyu; Tu, Chaoyang

2015-01-01

A notable disorder crystal Yb:Ca 3 La 2 (BO 3 ) 4 crystal with Yb 3+ ion doping concentration of 10 at.% was grown by the Czochralski method. The polarized absorption, polarized emission, and polarized gain cross sections were systematically calculated. The laser operations were investigated with Yb:Ca 3 La 2 (BO 3 ) 4 crystals cut along the a, b, and c crystallographic axes. The highest output power of 3.88 W was obtained by using the b-cut Yb:Ca 3 La 2 (BO 3 ) 4 crystal, with a slope efficiency of 62%. Additionally, it was confirmed that the output laser spectra were largely dependent on the output coupler. (paper)

Thermal analyzes of phosphate glasses doped with Yb{sup 3+} and ZnTe nanocrystals

Energy Technology Data Exchange (ETDEWEB)

Freitas, A.M.; Bell, M.J.V. [Laboratório de Espectroscopia de Materiais, Departamento de Física, ICE, Universidade Federal de Juiz de Fora, 36036-330 Juiz de Fora, MG (Brazil); Anjos, V., E-mail: virgilio@fisica.ufjf.br [Laboratório de Espectroscopia de Materiais, Departamento de Física, ICE, Universidade Federal de Juiz de Fora, 36036-330 Juiz de Fora, MG (Brazil); Pinheiro, A.S.; Dantas, N.O. [Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS), Instituto de Física da Universidade Federal de Uberlândia, CP 593, CEP 38400-902 Uberlândia, MG (Brazil)

2016-01-15

This work studies the thermal properties of a glass matrix called PZABP doped with ZnTe and co-doped with Yb{sup 3+} with nominal composition 60P{sub 2}O{sub 5}, 15ZnO, 5Al{sub 2}O{sub 3}, 10BaO, and 10 PbO (mol%). The presence of ZnTe results in the formation of nanocrystals which are evidenced by optical absorption, X-Ray Diffraction (XRD) and Raman scattering. Thermal lens and Volumetric Heat Capacity techniques were used to investigate thermal diffusivity (D), thermal conductivity (K) and optical path variation with temperature (ds/dT). The outcomes indicate high values for the thermal diffusivity and a relatively small thermal conductivity, i.e., around 2.6×10{sup −3} cm{sup 2}/s and 3.4×10{sup −3} W cm{sup −1} K{sup −1}, respectively. On the other hand, a low ds/dT value, 1.0×10{sup −6} K{sup −1}, was obtained as required for an active laser medium. Moreover, it has been observed that the matrix allows high concentration of dopants without compromising its thermal properties. As a result, PZABP glasses may be pointed out as a promising material to applications in high power photonics devices. - Highlights: • UV transparentglass matrix (PZABP) is used for Yb{sup 3+}doping. • Bulk like and quantum dots like crystals of ZnTe were grown. • Thermal properties point out PZABP as a material to high power photonics devices.

Enhanced photovoltaic performance of dye-sensitized solar cells based on NaYF4:Yb(3+), Er(3+)-incorporated nanocrystalline TiO2 electrodes.

Science.gov (United States)

Zhu, Guang; Wang, Hongyan; Zhang, Quanxin; Zhang, Li

2015-08-01

Near infrared to visible up-conversion of light by rare earth ion-doped phosphors (NaYF4:Yb(3+), Er(3+)) that convert multiple photons of lower energy to higher energy photons offer new possibilities for improved performance of photovoltaic devices. Here, up-conversion phosphor NaYF4:Yb(3+), Er(3+) doped nanocrystalline TiO2 films are designed and used as a electrode for dye-sensitized solar cells, and the photovoltaic performance of DSSCs based on composite electrodes are investigated. The results show the cell with NaYF4:Yb(3+), Er(3+) achieves a power conversion efficiency of 7.65% under one sun illumination (AM 1.5G, 100mWcm(-2)), which is an increase of 14% compared to the cell without NaYF4:Yb(3+), Er(3+) (6.71%). The performance improvement is attributed to the dual effects of enhanced light harvesting from extended light absorption range and increased light scattering, and lower electron transfer resistance. Copyright © 2015 Elsevier Inc. All rights reserved.

Structural and vibrational study of C-type doped rare earth sesquioxide Yb2-xCoxO3

International Nuclear Information System (INIS)

Farhat, L. Ben; Amami, M.; Hlil, E.K.; Hassen, R. Ben

2009-01-01

Polycrystalline samples with general formula Yb 2-x Co x O 3 (0 2 O 3 sesquioxide. The lattice parameters are found to vary linearly with the composition x. The cationic distribution over the two non-equivalent sites 8b and 24d of the space group Ia-3 is found to be preferentially. Replacing Yb 3+ by Co 3+ introduces slight changes in the atomic coordinates leading to an increase of the mean cation-anion distances. The ability of Raman spectroscopy to detect changes in local co-ordination is utilized. A pseudo-tetrahedral coordination for the Co 3+ in the 24d site was found.

Quantum efficiency of Yb{sup 3+}–ZnTe co-doped phosphate glass system

Energy Technology Data Exchange (ETDEWEB)

Falci, R.F.; Freitas, A.M.; Silva, G.H. [Laboratório de Espectroscopia de Materiais, Departamento de Física, ICE, Universidade Federal de Juiz de Fora, 36036-330, Juiz de Fora, MG (Brazil); Pinheiro, A.S. [Centro Federal de EducaçãoTecnológica Celso Suckow da Fonseca (CEFET/RJ) - Campus Petrópolis, CEP 25620-003, Petrópolis - RJ (Brazil); Dantas, N.O. [Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS), Instituto de Física da Universidade Federal de Uberlândia, CP 593, CEP 38400-902, Uberlândia, MG (Brazil); Anjos, V., E-mail: virgilio@fisica.ufjf.br [Laboratório de Espectroscopia de Materiais, Departamento de Física, ICE, Universidade Federal de Juiz de Fora, 36036-330, Juiz de Fora, MG (Brazil); Bell, M.J.V. [Laboratório de Espectroscopia de Materiais, Departamento de Física, ICE, Universidade Federal de Juiz de Fora, 36036-330, Juiz de Fora, MG (Brazil)

2016-08-15

The present paper deals with optical properties of a highly transparent phosphate glass co-doped with Yb{sup 3+} and ZnTe nanocrystals. The presence of ZnTe nanocrystals is due to a sequential melting–nucleation procedure evidenced by optical absorption and Atomic Force Microscopy. From the perspective of compositional variation of the dopants, photoluminescence and lifetime measurements were performed. As a result, it was demonstrated that the ZnTe nanocrystals increase the Yb{sup 3+} emission by a factor up to five, when the pumping wavelength is resonant with the ZnTe absorption. It was also verified that the ZnTe nanocrystals inhibit the self-trapping of the rare earth luminescence. As a consequence, the quantum efficiency of the {sup 5}F{sub 7/2}→{sup 5}F{sub 5/2} transitions of the Yb{sup 3+} is considerably increased. Finally, we have found that the glass thermal diffusivity is not sensitive to temperature variations comprising the interval from room temperature to cryogenic temperatures. This can be an important property when considering this material to future applications in high-power photonic devices.

Upconversion in rare earth ions doped TeO2-ZnO glass

International Nuclear Information System (INIS)

Mohanty, Deepak Kumar; Rai, Vineet Kumar

2012-01-01

The Er 3+ /Yb 3+ doped/codoped TeO 2 -ZnO glasses have been fabricated by conventional melt and quenching technique. The absorption spectra of the doped/codoped glasses have been performed. The visible upconversion emissions of both doped and codoped glasses have been observed using 808 nm diode laser excitation. The process involved in upconversion emissions has been discussed in detail. (author)

Luminescence and energy transfer of Tb3+-doped BaO-Gd2O3-Al2O3-B2O3-SiO2 glasses.

Science.gov (United States)

Zuo, Chenggang; Huang, Jinze; Liu, Shaoyou; Xiao, Anguo; Shen, Youming; Zhang, Xiangyang; Zhou, Zhihua; Zhu, Ligang

2017-12-05

Transparent Tb 3+ -doped BaO-Gd 2 O 3 -Al 2 O 3 -B 2 O 3 -SiO 2 glasses with the greater than 4g/cm 3 were prepared by high temperature melting method and its luminescent properties have been investigated by measured UV-vis transmission, excitation, emission and luminescence decay spectra. The transmission spectrum shows there are three weak absorption bands locate at about 312, 378 and 484nm in the glasses and it has good transmittance in the visible spectrum region. Intense green emission can be observed under UV excitation. The effective energy transfer from Gd 3+ ion to Tb 3+ ion could occur and sensitize the luminescence of Tb 3+ ion. The green emission intensity of Tb 3+ ion could change with the increasing SiO 2 /B 2 O 3 ratio in the borosilicate glass matrix. With the increasing concentration of Tb 3+ ion, 5 D 4 → 7 F J transitions could be enhanced through the cross relaxation between the two nearby Tb 3+ ions. Luminescence decay time of 2.12ms from 546nm emission is obtained. The results indicate that Tb 3+ -doped BaO-Gd 2 O 3 -Al 2 O 3 -B 2 O 3 -SiO 2 glasses would be potential scintillating material for applications in X-ray imaging. Copyright © 2017 Elsevier B.V. All rights reserved.

Spectroscopic investigations of OH{sup -} influence on near-infrared fluorescence quenching of Yb{sup 3+}/Tm{sup 3+} co-doped sodium-metaphosphate glasses

Energy Technology Data Exchange (ETDEWEB)

Terra, I.A.A. [Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, Av. Trabalhador Saocarlense 400, CEP 13566-590, USP-Sao Carlos, SP (Brazil)], E-mail: idelma@ifsc.usp.br; Camargo, A.S.S. de; Terrile, M.C.; Nunes, L.A.O. [Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, Av. Trabalhador Saocarlense 400, CEP 13566-590, USP-Sao Carlos, SP (Brazil)

2008-05-15

Energy transfer processes were studied in two sets of Yb{sup 3+} and Tm{sup 3+} co-doped sodium-metaphosphate glasses, prepared in air and nitrogen atmospheres. Using Foerster, Dexter, and Miyakawa theoretical models, the energy transfer parameters were calculated. The main ion-ion energy transfer processes analyzed were energy migration among Yb{sup 3+} ions, cross-relaxations between Yb{sup 3+} and Tm{sup 3+} ions, and interactions with OH{sup -} radicals. The results indicated that Yb{yields}Tm energy transfer favors 1.8 {mu}m emissions, and there is no evidence of concentration quenching up to 2% Tm{sub 2}O{sub 3} doping. As expected, samples prepared in nitrogen atmosphere present higher fluorescence quantum efficiency than those prepared in air, and this feature is specially noted in the near-infrared region, where the interaction with the OH{sup -} radicals is more pronounced.

Enhanced exciton emission from ZnO nano-phosphor induced by Yb3+ ions

CSIR Research Space (South Africa)

Kabongo, GL

2014-01-01

Full Text Available In this work, the sol–gel method was used to prepare Ytterbium (Yb(sup3+)) doped ZnO nano-phosphors with different concentrations of Yb(sup3+) ions. Their structural, morphological, photoluminescence, electronic states and the chemical composition...

Multi-component Ce doped (Gd,Y,La,Lu)3(AlGaSc)5O12 garnets – A new story in the development of scintillating single crystalline film screens

International Nuclear Information System (INIS)

Zorenko, Yu.; Gorbenko, V.; Savchyn, V.; Zorenko, T.; Fedorov, A.; Wrzesinski, H.; Vasylkiv, Ya.

2013-01-01

The paper is dedicated to development of the scintillators based on single crystalline films of Ce doped (GdLaYLu) 3 (AlGaSc) 5 O 12 multi-component garnets onto Gd 3 Ga 5 O 12 substrates using the liquid phase epitaxy method. -- Highlights: •Growth of Ce doped (GdYLaLu) 3 (AlGaSc) 5 O 12 garnets films by LPE method. •Luminescent and scintillation properties of Ce doped (GdYLaLu) 3 (AlGaSc) 5 O 12 films. •Influence of Pb 2+ flux related impurity on the light yield of Ce 3+ emission

Fabrication of a transparent ultraviolet detector by using n-type Ga2O3 and p-type Ga-doped SnO2 core-shell nanowires.

Science.gov (United States)

Hsu, Cheng-Liang; Lu, Ying-Ching

2012-09-21

This study investigates the feasibility of synthesizing high-density transparent Ga(2)O(3)/SnO(2):Ga core-shell nanowires on a sapphire substrate at 1000 °C by VLS. The doping Ga concentrations are 0.46, 1.07, 2.30 and 17.53 atomic%. The XRD spectrum and HR-TEM reveal Ga(2)O(3) and SnO(2) as having monoclinic and tetragonal rutile structures, respectively. Experimental results indicate that the XRD peak shift of SnO(2) to a larger angle increases with the increasing amount of Ga doping. According to the CL spectrum, SnO(2) and Ga(2)O(3) peak at approximately 528-568 nm and 422-424 nm, respectively. The maximum quantum efficiency of Ga(2)O(3)/SnO(2):Ga core-shell nanowires is around 0.362%. The UV light on-off current contrast ratio of Ga(2)O(3)/SnO(2):Ga core-shell nanowires is around 1066.7 at a bias of 5 V. Moreover, the dynamic response of Ga(2)O(3)/SnO(2):Ga core-shell nanowires has an on-off current contrast ratio of around 16. Furthermore, the Ga(2)O(3) region functions similar to a capacitor and continues to accumulate SnO(2):Ga excited electrons under UV light exposure.

Upconversion photoluminescence of epitaxial Yb{sup 3+}/Er{sup 3+} codoped ferroelectric Pb(Zr,Ti)O{sub 3} films on silicon substrates

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yang, E-mail: zhangy_acd@hotmail.com [IFW Dresden, P.O. Box 270116, D-01171 Dresden (Germany); Kämpfe, Thomas [Institut für Angewandte Physik, TU Dresden, 01062 Dresden (Germany); Bai, Gongxun [Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong (China); Mietschke, Michael; Yuan, Feifei; Zopf, Michael [IFW Dresden, P.O. Box 270116, D-01171 Dresden (Germany); Abel, Stefan [IBM Research GmbH, Saümerstrasse 4, 8803 Rüschlikon (Switzerland); Eng, Lukas M. [Institut für Angewandte Physik, TU Dresden, 01062 Dresden (Germany); Hühne, Ruben [IFW Dresden, P.O. Box 270116, D-01171 Dresden (Germany); Fompeyrine, Jean [IBM Research GmbH, Saümerstrasse 4, 8803 Rüschlikon (Switzerland); Ding, Fei, E-mail: f.ding@ifw-dresden.de [IFW Dresden, P.O. Box 270116, D-01171 Dresden (Germany); Schmidt, Oliver G. [IFW Dresden, P.O. Box 270116, D-01171 Dresden (Germany); Material Systems for Nanoelectronics, Chemnitz University of Technology, Reichenhainer strasse 70, 09107 Chemnitz (Germany)

2016-05-31

Thin films of Yb{sup 3+}/Er{sup 3+} codoped Pb(Zr,Ti)O{sub 3} (PZT:Yb/Er) have been epitaxially grown on the SrTiO{sub 3} buffered Si wafer by pulsed laser deposition. Strong upconversion photoluminescence was observed in the PZT:Yb/Er thin film. Using piezoresponse force microscopy, polar domains in the PZT:Yb/Er film can be reversibly switched with a phase change of 180°. Ferroelectric hysteresis loop shape with a well-saturated response was observed. The epitaxially grown lanthanide-doped PZT on silicon opens up a promising route to the integration of luminescent functional oxides on the silicon platform. - Highlights: • Epitaxial growth of Yb{sup 3+}/Er{sup 3+} codoped Pb(Zr,Ti)O{sub 3} films on SrTiO{sub 3} buffered silicon • Upconversion emissions were obtained from the lanthanide ion doped thin films. • Saturated ferroelectric hysteresis loops were observed. • Polar domains were switched by PFM with a phase change of 180°.

Analysis of structure origin and luminescence properties of Yb(3+)-Er(3+) co-doped fluorophosphate glass.

Science.gov (United States)

Chen, Fangze; Jing, Xufeng; Wei, Tao; Wang, Fengchao; Tian, Ying; Xu, Shiqing

2014-08-14

The near infrared luminescence properties of Yb(3+)-Er(3+) co-doped fluorophosphate glasses have been investigated. The various effects on structure and 1.53 μm emission were analyzed as a function of Yb(3+) concentration. The energy transfer mechanism was proposed. High measured lifetime (10.75 ms), large effective full widths at half maximum (73.71 nm) and large gain per unit length (62.8 × 10(-)(24)cm(2)s) have been achieved in prepared glass. The present glass co-doped with 6mol% YbF3 and 2 mol% ErF3 showed magnificent luminescence properties for telecommunication application. Copyright © 2014 Elsevier B.V. All rights reserved.

Optical properties and radiation response of Ce{sup 3+}-doped GdScO{sub 3} crystals

Energy Technology Data Exchange (ETDEWEB)

Yamaji, Akihiro; Fujimoto, Yutaka; Futami, Yoshisuke; Yokota, Yuui; Kurosawa, Shunsuke [Institute of Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); Kochurikhin, Vladimir [General Physics Institute, 38 Vavilov Str., 119991 Moscow (Russian Federation); Yanagida, Takayuki [New Industry Creation Hatchery Center, Tohoku University, 6-6-10 Aramaki, Aoba-ku, Sendai 980-8579 (Japan); Yoshikawa, Akira [Institute of Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); New Industry Creation Hatchery Center, Tohoku University, 6-6-10 Aramaki, Aoba-ku, Sendai 980-8579 (Japan)

2012-12-15

10%-Ce doped GdScO{sub 3} perovskite type single crystal was grown by the Czochralski process. The Ce concentration in the crystal was measured. No impurity phases were observed by powder X-ray diffraction analysis. We evaluated the optical and radiation properties of the grown crystal. Ce:GdScO{sub 3} crystal showed photo- and radio-luminescence peaks due to Ce{sup 3+} of 5d-4f transition and colour centre. The photoluminescence decay time was sub-ns order. The relative light yield under 5.5 MeV alpha-ray excitation was calculated to be approximately 9% of BGO. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Optical properties of highly crystalline Y2O3:Er,Yb nanoparticles prepared by laser ablation in water

International Nuclear Information System (INIS)

Nunokawa, Takashi; Odawara, Osamu; Wada, Hiroyuki

2014-01-01

Y 2 O 3 :Er,Yb nanoparticles were prepared by laser ablation in water. We investigated crystallinity, distribution of dopant, and optical properties of the prepared nanoparticles. The full-width half-maximum (FWHD) of the crystalline peak of nanoparticles measured by an x-ray diffractometer (XRD) barely changed. Further, using scanning transmission electron microscopy–energy dispersive x-ray spectroscopy (STEM–EDX), we confirmed the peaks of Y, Er, Yb, and O. Moreover, on the basis of the optical properties of the nanoparticles, the emission of red ( 2 F 9/2  →  4 I 15/2 ) and green ( 2 H 11/2 , 4 S 3/2  →  4 I 15/2 ) was confirmed. We also investigated the emission intensity as a function of the excitation power of 980 nm LD in the prepared nanoparticles. The photon avalanche effect was observed at the excitation power of 100 mW. These results confirmed that uniformly Er-Yb-doped Y 2 O 3 nanoparticles were successfully prepared by laser ablation in water. (paper)

Transparent glass–ceramics with (Eu{sup 3+},Yb{sup 3+}):YNbO{sub 4} nanocrystals: Crystallization, structure, optical spectroscopy and cooperative upconversion

Energy Technology Data Exchange (ETDEWEB)

Loiko, P.A. [Center for Optical Materials and Technologies (COMT), Belarusian National Technical University, 65/17 Nezavisimosti Ave., Minsk 220013 (Belarus); Dymshits, O.S., E-mail: vodym@goi.ru [NITIOM Vavilov State Optical Institute, 36/1 Babushkin St, Saint-Petersburg 192171 (Russian Federation); Alekseeva, I.P.; Zhilin, A.A.; Tsenter, M.Ya. [NITIOM Vavilov State Optical Institute, 36/1 Babushkin St, Saint-Petersburg 192171 (Russian Federation); Vilejshikova, E.V. [Center for Optical Materials and Technologies (COMT), Belarusian National Technical University, 65/17 Nezavisimosti Ave., Minsk 220013 (Belarus); Bogdanov, K.V. [National Research University of Information Technologies, Mechanics and Optics, Kronverkskiy pr., 49, 197101 Saint-Petersburg (Russian Federation); Mateos, X. [Física i Cristallografia de Materials i Nanomaterials (FiCMA-FiCNA), Universitat Rovira i Virgili (URV), Campus Sescelades, C/Marcellí Domingo, s/n, Tarragona E-43007 (Spain); Yumashev, K.V. [Center for Optical Materials and Technologies (COMT), Belarusian National Technical University, 65/17 Nezavisimosti Ave., Minsk 220013 (Belarus)

2016-11-15

In the present work, we report on a comprehensive study of crystallization, structure and optical spectroscopy of transparent glass–ceramics with (Eu{sup 3+},Yb{sup 3+}):YNbO{sub 4} nanocrystals synthesized by secondary heat-treatments of glass of the Li{sub 2}O–Al{sub 2}O{sub 3}–SiO{sub 2} system, for the first time, to the best of our knowledge. Heat treatments result in volume crystallization of RENbO{sub 4} with the sizes of 4–15 nm. Crystals of rare-earth niobates with disordered fluorite structure (T′) appear during heat-treatment at 720–740 °C for 6 h, crystals with tetragonal structure (T) appear at higher temperatures or longer durations of heat-treatment, and in samples heat-treated at 1000 °C, the monoclinic form (M) is detected additionally. Rare-earth niobates act as nucleating agents for bulk crystallization of β-quartz solid solutions, the main crystalline phase of the glass–ceramics, which ensures their good thermo-mechanical properties. Optical spectroscopy confirms entering of both Eu{sup 3+} and Yb{sup 3+} ions into the RENbO{sub 4} nanophase and their specroscopic properties variation according to the T′→T→M phase transformations. Under UV excitation, glass–ceramics heat-treated at 900 °C provide intense red emission with the color coordinates x=0.665, y=0.335 (CIE 1931). In the sample, heat-treated at 1000 °C, a partial reduction of Eu{sup 3+} to Eu{sup 2+} is observed which allows for tuning the color properties of emission. When excited in the near-IR by an InGaAs diode, the initial glass and glass–ceramics show red cooperative upconversion due to the 2Yb{sup 3+}→Eu{sup 3+} energy transfer. The efficiency of the latter is ~10%. The developed materials due to the good emission and thermo-mechanical properties are promising for the development of color-tunable red phosphors.

Photoluminescence study of Sm{sup 3+}–Yb{sup 3+}co-doped tellurite glass embedding silver nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Reza Dousti, M., E-mail: mrdousti@ifsc.usp.br [Laboratório de Espectroscopia de Materiais Funcionais (LEMAF), Instituto de Fisica de São Carlos, Universidade de São Paulo, Av. Trabalhador So-carlense 400, São Carlos, SP 13566-590 (Brazil); Department of Physics, Tehran-North Branch, Islamic Azad University Tehran (Iran, Islamic Republic of); Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, Skudai 81310, Johor (Malaysia); Amjad, R.J. [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, Skudai 81310, Johor (Malaysia); Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Hosseinian S, R.; Salehi, M.; Sahar, M.R. [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, Skudai 81310, Johor (Malaysia)

2015-03-15

We report on the upconversion emission of Sm{sup 3+} ions doped tellurite glass in the presence of Yb{sup 3+} ions and silver nanoparticles. The enhancement of infrared-to-visible upconversion emissions is achieved under 980 nm excitation wavelength and attributed to the high absorption cross section of Yb{sup 3+} ions and an efficient energy transfer to Sm{sup 3+} ions. Further enhancements are attributed to the plasmonic effect via metallic nanoparticles resulting in the large localized field around rare earth ions. However, under excitation at 406 nm, the addition of Yb{sup 3+} content and heat-treated silver nanoparticles quench the luminescence of Sm{sup 3+} ions likely due to quantum cutting and plasmonic diluent effects, respectively. - Highlights: • Sm{sup 3+} tellurite glasses co-doped with Yb{sup 3+} ions and tri-doped with Yb{sup 3+}:Ag NPs were prepared. • In first step, Yb{sup 3+} ions enhanced the upconversion emissions of Sm{sup 3+} doped samples. • In second step, Ag NPs further enhanced the upconversion emissions in tri-doped glasses. • Finally, the quench in luminescence under 406 nm excitation is observed and discussed.

Visible and near infrared up-conversion luminescence in Yb3+/Tm3+ co-doped yttria-alumino-silicate glass based optical fibers

International Nuclear Information System (INIS)

Halder, Arindam; Chandra Paul, Mukul; Wadi Harun, Sulaiman; Kumar Bhadra, Shyamal; Bysakh, Sandip; Das, Shyamal; Pal, Mrinmay

2013-01-01

We report blue light up-conversion (UC) emission in Yb–Tm co-doped nano-phase separated yttria-alumino-silicate (YAS) glass based D-shaped with low-index cladding optical fibers. Y 2 O 3 creates an environment of nano structured YAS glass phases with Yb and Tm rich zone into the core glass which confirmed from TEM analyses. This kind of glass host assists in distributing of Yb and Tm rich zone uniformly throughout the core region. Yb and Tm doped regions exist mainly into nano YAS phases, defined as RE rich nano YAS-RE phases. All samples exhibit UC luminescence peaks at 483 nm, 650 nm and 817 nm for Tm 3+ and 1044 nm for Yb 3+ under excitation by 975 nm laser light. In such type of nano-engineered glass–ceramic based host, almost all the Yb ions transferred its energy to the nearer Tm ions. In particular 483 nm emission is attributed to 1 G 4 → 3 H 6 transition through a three step resonance energy transfer (ET) from excited Yb 3+ . The highest emission intensity is obtained with a concentration of 0.5 wt% Tm 3+ and 2.0 wt% Yb 3+ . The ET between Yb 3+ and Tm 3+ is increased with increase of Yb 3+ concentration with respect to Tm 3+ . The experimental fluorescence life-times of Tm 3+ upconversion emission at visible wavelengths into such kind of fiber is reported under 975 nm pump excitation. The present study is important for development of an efficient tunable 483 nm fluorescence light source. -- Highlights: • We report nano-phase separated YAS glass host based Yb–Tm co-doped optical fibers. • Almost all the Yb transferred its energy to the neighboring Tm ions. • We report strong UC luminescence peaks at 483 nm and 817 nm wavelengths. • We report third ET coefficient as 1.6723 Hz for such kind of Yb–Tm codoped fiber. • We report suitable fiber as an efficient tunable 483 nm fluorescence light source

Synthesis of green emission upconversion phosphor nanosheets (LaNb{sub 2}O{sub 7}) doped with Er{sup 3+} and Yb{sup 3+}

Energy Technology Data Exchange (ETDEWEB)

Takasugi, Soichi [Course of Science and Technology, Graduate School of Science and Technology, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan); Iida, Riku [Department of Chemistry, School of Science, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan); Tomita, Koji, E-mail: tomita@keyaki.cc.u-tokai.ac.jp [Department of Chemistry, School of Science, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan); Iwaoka, Michio [Course of Science and Technology, Graduate School of Science and Technology, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan); Department of Chemistry, School of Science, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan); Katagiri, Kiyofumi [Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima 739-8527 (Japan); Osada, Minoru [International Center for Materials Nano architectonics (MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Kakihana, Masato [Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan)

2016-05-15

LaNb{sub 2}O{sub 7}:Er{sup 3+},Yb{sup 3+} upconversion (UPC) phosphor nanosheets were prepared by exfoliating a KLaNb{sub 2}O{sub 7}:Er{sup 3+},Yb{sup 3+} layered compound. Highly crystalline nanosheets with a thickness and lateral size of 3.91 nm and approximately 300 nm, respectively, were obtained. The UPC emission intensity of the nanosheets was 7.6 times greater than that of mechanically milled particles (100–500 nm) of bulk KLaNb{sub 2}O{sub 7}:Er{sup 3+},Yb{sup 3+}. The UPC emission intensities of the nanosheets dispersed in different solvents (H{sub 2}O, D{sub 2}O, CH{sub 3}OH, CH{sub 2}Cl{sub 2}, and CCl{sub 4}) were measured, and the intensities were observed to decrease in the order CCl{sub 4}>CH{sub 2}Cl{sub 2}>D{sub 2}O>CH{sub 3}OH>H{sub 2}O. Because of the large surface area of the nanosheets, their emission intensity was decreased depending on the solvent's vibrational energy. - Highlights: • La{sub 0.45}Er{sub 0.05}Yb{sub 0.5}Nb{sub 2}O{sub 7} nanosheets were synthesized by a soft breakdown method (exfoliation). • The lateral size and thickness of the nanosheets were approximately 300 nm and approximately 3.91 nm, respectively. • The exfoliated nanosheets exhibited bright upconversion emission 7.6 times more intense than that of the milled sample (100–500 nm). • The nanosheets dispersed in solvents exhibited greatly different upconversion emission intensities depending on the solvent's vibrational energy.

Amorphous and crystalline In_2O_3-based transparent conducting films for photovoltaics

International Nuclear Information System (INIS)

Koida, Takashi

2017-01-01

We reported solar cells with reduced electrical and optical losses using hydrogen-doped In_2O_3 (In_2O_3:H) transparent conducting layers with low sheet resistance and high transparence characteristics. The transparent conducting oxide (TCO) films were prepared by solid-phase crystallization of amorphous (a-) In_2O_3:H films grown by magnetron sputtering. The polycrystalline (poly-) In_2O_3:H films exhibited electron mobilities (over 100 cm"2V"-"1 s"-"1) 2 and 3 times greater than those of conventional TCO films. This paper describes (i) the current status of the electrical properties of In_2O_3-based TCO; (ii) the structural and optoelectrical properties of the a-In_2O_3:H and poly-In_2O_3:H films, focusing on the inhomogeneity and stability characteristics of the films; and (iii) the electrical properties of bilayer TCO. The potential of these high mobility TCO films for solar cells was also described. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Formation enthalpies of LaLn'O{sub 3} (Ln'=Ho, Er, Tm and Yb) interlanthanide perovskites

Energy Technology Data Exchange (ETDEWEB)

Qi, Jianqi [Peter A. Rock Thermochemistry Laboratory and NEAT ORU, University of California, Davis, CA 95616 (United States); College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Key Laboratory of Radiation Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China); Key Laboratory of High Energy Density Physics of Ministry of Education, Sichuan University, Chengdu 610064 (China); Guo, Xiaofeng [Peter A. Rock Thermochemistry Laboratory and NEAT ORU, University of California, Davis, CA 95616 (United States); Mielewczyk-Gryn, Aleksandra [Peter A. Rock Thermochemistry Laboratory and NEAT ORU, University of California, Davis, CA 95616 (United States); Faculty of Applied Physics and Mathematics, Department of Solid State Physics, Gdansk University of Technology, Narutowicza 11/12, 80-233 Gdansk (Poland); Navrotsky, Alexandra, E-mail: anavrotsky@ucdavis.edu [Peter A. Rock Thermochemistry Laboratory and NEAT ORU, University of California, Davis, CA 95616 (United States)

2015-07-15

High-temperature oxide melt solution calorimetry using 3Na{sub 2}O·MoO{sub 3} at 802 °C was performed for interlanthanide perovskites LaLn'O{sub 3} (Ln'=Ho, Er, Tm and Yb) and lanthanide oxides (La{sub 2}O{sub 3}, Ho{sub 2}O{sub 3}, Er{sub 2}O{sub 3}, Tm{sub 2}O{sub 3} and Yb{sub 2}O{sub 3}). The enthalpies of formation of these interlanthanide perovskites from binary lanthanide oxides at room temperature (25 °C) were determined to be −8.3±3.4 kJ/mol for LaHoO{sub 3}, −9.9±3.0 kJ/mol for LaErO{sub 3}, −10.8±2.7 kJ/mol for LaTmO{sub 3} and −12.3±2.9 kJ/mol for LaYbO{sub 3}. There is a roughly linear relationships between these enthalpy values and the tolerance factor for these and for other LaM{sup 3+}O{sub 3} (M=In, Sc, Ga, Al, Fe and Cr) perovskites, confirming that the distortion of the perovskites as results from ionic radius difference of A-site and B-site cations, is the main factor determining the stability of these compounds. - Graphical abstract: A linear relationship between the enthalpy of formation and the tolerance factor for interlanthanide LaLn'O{sub 3} (Ln'=Ho, Er, Tm, and Yb) and other LaM{sup 3+}O{sub 3} (M=In, Sc, Ga, Al, Fe and Cr) perovskites. - Highlights: • Interlanthanide perovskites were synthesized by solid state reactions. • Their enthalpies of formation were measured by oxide melt solution calorimetry. • ΔH{sub f,ox} shows a linear relationship with tolerance factor.

High energy transmission of Al2O3 doped with light transition metals

KAUST Repository

Schuster, Cosima

2012-01-31

The transmission of transparent colored ceramics based on Al2O3doped with light transition metals is measured in the visible and infrared range. To clarify the role of the dopands we perform ab initiocalculations. We discuss the electronic structure and present optical spectra obtained in the independent particle approximation. We argue that the gross spectral features of Co- and Ni-doped Al2O3 samples are described by our model, while the validity of the approach is limited for Cr-doped Al2O3.

High energy transmission of Al2O3 doped with light transition metals

KAUST Repository

Schuster, Cosima; Klimke, J.; Schwingenschlö gl, Udo

2012-01-01

The transmission of transparent colored ceramics based on Al2O3doped with light transition metals is measured in the visible and infrared range. To clarify the role of the dopands we perform ab initiocalculations. We discuss the electronic structure and present optical spectra obtained in the independent particle approximation. We argue that the gross spectral features of Co- and Ni-doped Al2O3 samples are described by our model, while the validity of the approach is limited for Cr-doped Al2O3.

Near-infrared photoluminescence in La0.98AlO3: 0.02Ln3+(Ln = Nd/Yb) for sensitization of c-Si solar cells

Science.gov (United States)

Sawala, N. S.; Koparkar, K. A.; Bajaj, N. S.; Omanwar, S. K.

2016-05-01

The host matrix LaAlO3 was synthesized by conventional solid state reaction method in which the Nd3+ ions and Yb3+ ions successfully doped at 2mol% concentrations. The phase purity was confirmed by X ray powder diffraction (XRD) method. The photoluminescence (PL) properties were studied by spectrophotometer in near infra red (NIR) and ultra violet visible (UV-VIS) region. The Nd3+ ion doped LaAlO3 converts a visible (VIS) green photon (587 nm) into near infrared (NIR) photon (1070 nm) while Yb3+ ion doped converts ultra violet (UV) photon (221 nm) into NIR photon (980 nm). The La0.98AlO3: 0.02Ln3+(Ln = Nd / Yb) can be potentiality used for betterment of photovoltaic (PV) technology. This result further indicates its potential application as a luminescence converter layer for enhancing solar cells performance.

Y2O3:Yb,Er@mSiO2-CuxS double-shelled hollow spheres for enhanced chemo-/photothermal anti-cancer therapy and dual-modal imaging

Science.gov (United States)

Yang, Dan; Yang, Guixin; Wang, Xingmei; Lv, Ruichan; Gai, Shili; He, Fei; Gulzar, Arif; Yang, Piaoping

2015-07-01

Multifunctional composites have gained significant interest due to their unique properties which show potential in biological imaging and therapeutics. However, the design of an efficient combination of multiple diagnostic and therapeutic modes is still a challenge. In this contribution, Y2O3:Yb,Er@mSiO2 double-shelled hollow spheres (DSHSs) with up-conversion fluorescence have been successfully prepared through a facile integrated sacrifice template method, followed by a calcination process. It is found that the double-shelled structure with large specific surface area and uniform shape is composed of an inner shell of luminescent Y2O3:Yb,Er and an outer mesoporous silica shell. Ultra small CuxS nanoparticles (about 2.5 nm) served as photothermal agents, and a chemotherapeutic agent (doxorubicin, DOX) was then attached onto the surface of mesoporous silica, forming a DOX-DSHS-CuxS composite. The composite exhibits high anti-cancer efficacy due to the synergistic photothermal therapy (PTT) induced by the attached CuxS nanoparticles and the enhanced chemotherapy promoted by the heat from the CuxS-based PTT when irradiated by 980 nm near-infrared (NIR) light. Moreover, the composite shows excellent in vitro and in vivo X-ray computed tomography (CT) and up-conversion fluorescence (UCL) imaging properties owing to the doped rare earth ions, thus making it possible to achieve the target of imaging-guided synergistic therapy.Multifunctional composites have gained significant interest due to their unique properties which show potential in biological imaging and therapeutics. However, the design of an efficient combination of multiple diagnostic and therapeutic modes is still a challenge. In this contribution, Y2O3:Yb,Er@mSiO2 double-shelled hollow spheres (DSHSs) with up-conversion fluorescence have been successfully prepared through a facile integrated sacrifice template method, followed by a calcination process. It is found that the double-shelled structure with large

Characterization of the lasing properties of a 5%Yb doped Lu.sub.2./sub.SiO.sub.5./sub. crystal along its three optical axes

Czech Academy of Sciences Publication Activity Database

Toci, G.; Pirri, A.; Beitlerová, Alena; Shoji, Y.; Yoshikawa, A.; Hybler, Jiří; Nikl, Martin; Vannini, M.

2015-01-01

Roč. 23, č. 10 (2015), s. 13210-13221 ISSN 1094-4087 Institutional support: RVO:68378271 Keywords : Lu 2 SiO 5 * Yb-doped * laser Subject RIV: BH - Optics, Masers, Lasers Impact factor: 3.148, year: 2015

Cooperative up-conversion processes in SrAl{sub 4}O{sub 7}:Yb and SrAl{sub 4}O{sub 7}:Yb,Tb and their dependence on charge compensation by Na

Energy Technology Data Exchange (ETDEWEB)

Puchalska, M., E-mail: malgorzata.puchalska@chem.uni.wroc.pl [Faculty of Chemistry, University of Wroclaw, 14, F. Joliot-Curie Street, 50-383 Wroclaw (Poland); Zych, E. [Faculty of Chemistry, University of Wroclaw, 14, F. Joliot-Curie Street, 50-383 Wroclaw (Poland); Watras, A. [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, 2 Okólna Street, 50-422 Wrocław (Poland)

2017-03-15

A detailed analysis of the luminescence behaviour of Yb{sup 3+}-doped and Yb{sup 3+}-Tb{sup 3+} co-doped strontium aluminates powders: Sr{sub 1-x}Yb{sub x}Al{sub 4}O{sub 7} (x=0.002–0.07) and Sr{sub 1-x-y}Yb{sub x}Tb{sub y}Al{sub 4}O{sub 7} (x=0.03; y=0.002–0.02) were performed. The studies of singly doped samples show that direct excitation of Yb{sup 3+} by means of {sup 2}F{sub 7/2}-{sup 2}F{sub 5/2} absorption at 900–980 nm leads to Stokes Yb{sup 3+} emission in the range of 970–1130 nm as well as bluish-green Yb{sup 3+} cooperative luminescence (CL) whose energy doubles that of the NIR one. The effect of activator concentration and charge compensation through Na{sup +} co-doping on both Yb{sup 3+} emissions were also studied. It was found that Na{sup +} addition enhanced Stokes Yb{sup 3+} photoluminescence brightness, while the cooperative emission intensity appeared to be lower. In doubly Yb{sup 3+}-Tb{sup 3+} doped materials excitation at 980 nm led to cooperative sensitization of the Tb{sup 3+} {sup 5}D{sub 4} level giving rise to its green {sup 5}D{sub 4}→{sup 7}F{sub J} (J={sup 7}F{sub 6}-{sup 7}F{sub 3}) up-conversion luminescence with the dominant component around 542 nm. The cooperative energy transfer (CET) mechanism was proposed basing on the results obtained from emission and absorption spectra, decay kinetics as well as the dependence of UC luminescence intensity on NIR excitation power.

Photon up-conversion production in Tb{sup 3+}–Yb{sup 3+} co-doped CaF{sub 2} phosphors prepared by combustion synthesis

Energy Technology Data Exchange (ETDEWEB)

Rakov, Nikifor, E-mail: nikifor.gomez@univasf.edu.br [PG—Ciência dos Materiais, Universidade Federal do Vale do São Francisco, 48902-300 Juazeiro, BA (Brazil); Guimarães, Renato B. [Instituto de Física, Universidade Federal Fluminense, 24210-346 Niterói, RJ (Brazil); Maciel, Glauco S., E-mail: glauco@if.uff.br [Instituto de Física, Universidade Federal Fluminense, 24210-346 Niterói, RJ (Brazil)

2016-02-15

Graphical abstract: Up-conversion luminescence from Tb{sup 3+} obtained by energy transfer from Yb{sup 3+} pairs in CaF{sub 2} powder prepared by combustion synthesis. - Highlights: • Calcium fluoride (CaF{sub 2}) powders were prepared by combustion synthesis. • Rare-earth ions doped in this material were found in interstitial sites. • Cooperative up-conversion was observed in Tb{sup 3+}:Yb{sup 3+}:CaF{sub 2} powder. • Energy transfer between Tb{sup 3+} and pairs of Yb{sup 3+} was analyzed using rate equations. - Abstract: Calcium fluoride (CaF{sub 2}) crystalline powders were successfully prepared by the combustion synthesis method. The powder material containing luminescent rare-earth ions, more specifically terbium (Tb{sup 3+}) and ytterbium (Yb{sup 3+}), was studied by X-ray diffraction, scanning electronic microscopy and optical spectroscopy. These ions are allocated in charge compensated interstitial positions of tetragonal (C{sub 4v}) and trigonal (C{sub 3v}) symmetry sites of the cubic (O{sub h}) CaF{sub 2} lattice. Up-conversion (UC) luminescence in Tb{sup 3+} was achieved using a low power diode laser operating at 975 nm. Tb{sup 3+} is insensitive to near-infrared radiation but UC can be achieved via energy transfer from pairs of Yb{sup 3+} ions to Tb{sup 3+} ions. The UC luminescence dynamics of Tb{sup 3+} was used to study the energy transfer mechanism.

Spectroscopic studies of lutetium pyro-silicates Lu2Si2O7 doped with bismuth and europium

International Nuclear Information System (INIS)

Bretheau-Raynal, Francoise

1981-01-01

Single crystals of thortveitite structure pyro-silicates were grown by a floating zone technique associated with an arc image furnace. The samples were systematically characterized by X-Ray diffraction and microprobe analysis. Thanks to oriented single crystals of Lu 2 Si 2 O 7 , Yb 2 Si 2 O 7 and Sc 2 Si 2 O 7 , the recorded infrared and Raman spectra allow complete attribution of internal and external vibration modes, in good agreement with group theory predictions for C 2h factor group. Spectroscopic studies of Eu 3+ doping ion in Lu 2 Si 2 O 7 confirm C 2 point symmetry for the cationic site. Oscillator strengths and Judd-Ofelt parameters for Eu 3+ were calculated. A three level scheme ( 1 S 0 , 3 P 0 , 3 P 1 ) of Bi 3+ ion is used to explain radiative and non radiative mechanisms in Lu 2 Si 2 O 7 doped with bismuth. Finally, the mechanisms of low temperature (T =9 K) energy transfer between Bi 3+ and Eu 3+ in lutetium pyro-silicate was studied. The transfer occurs by non radiative process, without any diffusion of the excitation energy within the donor system and is due to dipole-dipole interactions between Bi 3+ and Eu 3+ ions. (author) [fr

Microwave hydrothermal synthesis and upconversion properties of Yb3+/Er3+ doped YVO4 nanoparticles.

Science.gov (United States)

Kshetri, Yuwaraj K; Regmi, Chhabilal; Kim, Hak-Soo; Lee, Soo Wohn; Kim, Tae-Ho

2018-05-18

Yb 3+ and Er 3+ doped YVO 4 (Yb 3+ /Er 3+ :YVO 4 ) nanoparticles with highly efficient near-infrared to visible upconversion properties have been synthesized by microwave hydrothermal process. Uniform-sized Yb 3+ /Er 3+ :YVO 4 nanoparticles were synthesized within 1 h at 140 °C which is relatively faster than the conventional hydrothermal process. Under 980 nm laser excitation, strong green and less strong red emissions are observed which are attributed to 2 H 11/2 , 4 S 3/2 to 4 I 15/2 and 4 F 9/2 to 4 I 15/2 transitions of Er 3+ respectively. The emission intensity is found to depend strongly on the concentration of Yb 3+ . The quadratic dependence of upconversion intensity on the excitation power indicates that the upconversion process is governed by two-photon absorption process.

Microwave hydrothermal synthesis and upconversion properties of Yb3+/Er3+ doped YVO4 nanoparticles

Science.gov (United States)

Kshetri, Yuwaraj K.; Regmi, Chhabilal; Kim, Hak-Soo; Wohn Lee, Soo; Kim, Tae-Ho

2018-05-01

Yb3+ and Er3+ doped YVO4 (Yb3+/Er3+:YVO4) nanoparticles with highly efficient near-infrared to visible upconversion properties have been synthesized by microwave hydrothermal process. Uniform-sized Yb3+/Er3+:YVO4 nanoparticles were synthesized within 1 h at 140 °C which is relatively faster than the conventional hydrothermal process. Under 980 nm laser excitation, strong green and less strong red emissions are observed which are attributed to 2H11/2, 4S3/2 to 4I15/2 and 4F9/2 to 4I15/2 transitions of Er3+ respectively. The emission intensity is found to depend strongly on the concentration of Yb3+. The quadratic dependence of upconversion intensity on the excitation power indicates that the upconversion process is governed by two-photon absorption process.

Infrared emission properties and energy transfer in ZnO-SiO2:Yb3+ composites

International Nuclear Information System (INIS)

Xiao, F.; Chen, R.; Shen, Y.Q.; Liu, B.; Gurzadyan, G.G.; Dong, Z.L.; Zhang, Q.Y.; Sun, H.D.

2011-01-01

Graphical abstract: Highlights: → ZnO-SiO 2 :Yb 3+ composites have been prepared via a facile sol-gel method. Intense near-infrared emission at around 1 μm has been obtained upon broadband ultraviolet light excitation. → Efficient energy transfer from ZnO quantum dots to Yb 3+ ions has been clarified by the systematic measurements and analysis of static and time resolved photoluminescence spectra. → Codoping with Li + ions leads to about twice enhancement of the near-infrared luminescence intensity around 1 μm at room temperature. - Abstract: Intense near-infrared emission at 1 μm has been obtained in ZnO-SiO 2 :Yb 3+ composites via a facile sol-gel method upon broadband ultraviolet light excitation. Systematic optical measurements including static and time-resolved photoluminescence have been performed to elucidate the energy transfer from ZnO quantum dots to Yb 3+ ions. The dependence of energy transfer efficiency on Yb 3+ concentration has been investigated in detail. Codoping with Li + ions leads to about twice enhancement of the near-infrared luminescence intensity around 1 μm at room temperature. The enhancement in the luminescence intensity could be mostly attributed to the modification of the local symmetry around Yb 3+ ions by codoping with Li + ions.

Synthesis and thermoelectric properties of rare earth Yb-doped Ba8−xYbxSi30Ga16 clathrates

International Nuclear Information System (INIS)

Liu, Lihua; Li, Feng; Wei, Yuping; Chen, Ning; Bi, Shanli; Qiu, Hongmei; Cao, Guohui; Li, Yang

2014-01-01

Highlights: • Samples with the chemical formula Ba8− x Yb x Si 30 Ga 16 (x = 0, 0.5, 0.7, 1 and 1.5) were prepared. • Some Yb atoms enter the clathrate lattice to replace Ba, while other Yb atoms are oxidized as Yb 2 O 3 . • The thermal conductivity decreases with Yb-doping. • Thermoelectric figure of merit ZT significantly increased. -- Abstract: The potential thermoelectric and magnetic application of clathrate materials with rare-earth doping is the focus of much of the recent research activity in the synthetic material physics and chemistry. A series of clathrate samples with the chemical formula Ba 8−x Yb x Si 30 Ga 16 (x = 0, 0.5, 0.7, 1 and 1.5) were prepared by combining arc melting, ball milling and spark plasma sintering (SPS) techniques. X-ray diffraction and scanning electronic microscopy combined with energy-dispersive X-ray spectroscopy (EDS) analysis showed the dominant phase to be the type-I clathrate. Whereas, X-ray structural refinement and EDS analysis indicated that some Yb atoms enter the clathrate lattice to replace Ba at 2a sites, while other Yb atoms are oxidized as Yb 2 O 3 precipitated around grain boundaries. The solid solubility of Yb into clathrate lattice yielded x ∼ 0.3. Comparative analysis between Yb-doped and Yb-free clathrates showed that the thermal conductivity decreases with Yb-doping. Consequently, thermoelectric figure of merit ZT significantly increased

Luminescence dosemeter of the Al{sub 2}O{sub 3}:Er,Yb

Energy Technology Data Exchange (ETDEWEB)

Goncalves, Katia A.; Ventieri, Alexandre; Bitencourt, Jose F.S. [Universidade de Sao Paulo (EP/USP), SP (Brazil). Escola Politecnica. Dept. de Engenharia Eletrica; Mittani, Juan C.R.; Tatumi, Sonia H. [Faculdade de Tecnologia de Sao Paulo (CEETEPS), SP (Brazil)

2011-07-01

The present work deals with the thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) properties of {alpha}-Al{sub 2}O{sub 3}: Er,Yb obtained by sol gel process. Nanocrystals formations composed by Er{sub 2}O{sub 3}, Yb{sub 2}O{sub 3} and Yb{sub 3}Al{sub 5}O{sub 12} were observed by TEM images, EDS, electron beam diffraction and RXD, located at the surface of the alumina grains. The sample codoped with 1mol% of Er and 2 mol% of Yb supplied the best results for TL and OSL responses. The growth of the intensity of dosimetric TL peak at 205 deg C was linear with gamma radiation doses and the same behavior was observed in OSL growth curve. The luminescence fading of the sample after a dose of 5 Gy was found initially for a period of 30 days and minimum detectable dose measured for TL was 60.78 mGy and for OSL was 13.09 mGy. (author)

Violet and visible up-conversion emission in Yb{sup 3+}-Ho{sup 3+} co-doped germanium-borate glasses

Energy Technology Data Exchange (ETDEWEB)

Yang Yanmin, E-mail: mihuyym@163.co [College of Physics Science and Technology, Hebei University, Baoding 071002 (China); Zhang Meixin [Forensic Science Lab, Hebei University, Baoding 071002 (China); Yang Zhiping [College of Physics Science and Technology, Hebei University, Baoding 071002 (China); Fu Zuoling [Key Laboratory of Coherent Light, Atomic and Molecular Spectroscopy, College of physics, Jilin University, Ministry of Education, Changchun 130023 (China)

2010-10-15

The up-conversion emission properties of Yb{sup 3+}-Ho{sup 3+} 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 I{sub Red}/I{sub Green} increased with increasing B{sub 2}O{sub 3} 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 Yb{sup 3+}-Ho{sup 3+} co-doped germanium-borate glasses could be an alternative for the generation of violet and primary colors for application in solid-state displays.

Enhanced persistent red luminescence in Mn2+-doped (Mg,Zn)GeO3 by electron trap and conduction band engineering

Science.gov (United States)

Katayama, Yumiko; Kayumi, Tomohiro; Ueda, Jumpei; Tanabe, Setsuhisa

2018-05-01

The effect of Zn substitution on the persistent luminescence properties of MgGeO3:Mn2+-Ln3+ (Ln = Eu and Yb) red phosphors was investigated. The intensity of the persistent luminescence of the Eu3+ co-doped phosphors increased with increasing Zn content, whereas that of the Yb3+ co-doped samples decreased. For both series of lanthanide co-doped samples, the thermoluminescence (TL) glow peak shifted to the lower temperature side with increasing Zn content. These persistent luminescence properties were well explained in terms of lowering of the bottom of the conduction band relative to the ground state of the divalent lanthanide ions. Especially, in Eu3+ co-doped system, TL peak shifted from 520 K to 318 K by 50% Zn substitution. The persistent radiance of the (Mg0.5 Zn0.5)GeO3: Mn2+-Eu3+ sample at 1 h after ceasing UV light was 46 times stronger than that of MgGeO3:Mn2+-Eu3+, and 11 times stronger than that of ZnGa2O4: Cr3+ standard deep red persistent phosphor.

Near infra red light emitting Y2Sn2O7: Yb-Er nanoparticles

International Nuclear Information System (INIS)

Nigam, Sandeep; Sudarsan, V.; Vatsa, R.K.

2011-01-01

There is an increasing interest in erbium doped nanomaterials host, since they emit in the near-infrared region and are potential candidates for optical telecommunication, high-power and infrared lasers. Further, erbium-ytterbium-co-doped matrices have been particularly investigated as Yb 3+ ions play the role of sensitizers. In the present work, Y 2 Sn 2 O 7 nanoparticles co-doped with lanthanide ions Yb 3+ and Er 3+ were prepared based on the urea hydrolysis of Y 3+ , Sn 4+ , and Ln 3+ in ethylene glycol medium at 150 deg C followed by heating at 700 deg C. As prepared samples are amorphous in nature, and the sample heated at 700 deg C showed well crystalline pyrochlore structure. Based on TEM studies, it has been established that nano-particles are highly crystalline, with size range in the range of 2-5 nm. Luminescence measurements were carried out for the as prepared samples and those heated at 700 deg C. As prepared sampled showed very poor luminescence. However on heating to 700 deg C, strong emission in the NIR region was observed upon UV-excitation as can be seen. The peak observed around 1530 nm has been attributed to 4 I 13/2 → 4 I 15/2 transition of Er 3+ and the peak around 980 nm is due to 2 F 5/2 → 2 F 7/2 transition of Yb 3+ . (author)

Up-conversion mechanisms in Er{sup 3+} doped YbAG crystals

Energy Technology Data Exchange (ETDEWEB)

Kaczkan, Marcin; Borowska, Maja [Institute of Microelectronics and Optoelectronics PW, Warsaw (Poland); Malinowski, Michal [Institute of Microelectronics and Optoelectronics PW, Warsaw (Poland); Institute of Electronic Materials Technology, Warsaw (Poland); Lukasiewicz, Tadeusz; Kolodziejak, Katarzyna [Institute of Electronic Materials Technology, Warsaw (Poland)

2009-07-15

Up-conversion phenomena leading to the red, green and violet emissions in erbium doped ytterbium-aluminum garnet (YbAG) are investigated. Absorption and emission spectra and luminescence dynamics from various excited states of YbAG:Er{sup 3+} were registered. The low temperature absorption spectra were used to determine Stark levels energies of Er{sup 3+} ion in the investigated host. Emissions from the high lying excited states {sup 2}G{sub 9/2}, {sup 4}S{sub 3/2} and {sup 4}F{sub 9/2} of Er{sup 3+} were characterized under pulsed multi-photon IR excitation in the region of wavelength corresponding to the strong {sup 2}F{sub 7/2} {yields} {sup 2}F{sub 5/2} absorption transition of Yb{sup 3+} ions. Using the rate equations formalism the dynamics of the observed emissions were modeled. From the comparison of the measured and calculated decays the energy transfer rates between Yb{sup 3+} and Er{sup 3+} ions were evaluated. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Upconversion improvement in KLaF{sub 4}:Yb{sup 3+}/Er{sup 3+} nanoparticles by doping Al{sup 3+} ions

Energy Technology Data Exchange (ETDEWEB)

Zhou, Haifang [Fuzhou University, School of Physics and Information Engineering, and Institute of Micro-Nano Devices and Solar Cells, Fuzhou (China); Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou, Jiangsu (China); Wang, Xiechun; Lai, Yunfeng; Cheng, Shuying; Zheng, Qiao; Yu, Jinlin [Fuzhou University, School of Physics and Information Engineering, and Institute of Micro-Nano Devices and Solar Cells, Fuzhou (China)

2017-10-15

Rare-earth ion-doped upconversion (UC) materials show great potential applications in optical and optoelectronic devices due to their novel optical properties. In this work, hexagonal KLaF{sub 4}:Yb{sup 3+}/Er{sup 3+} nanoparticles (NPs) were successfully synthesized by a hydrothermal method, and remarkably enhanced upconversion luminescence in green and red emission bands in KLaF{sub 4}:Yb{sup 3+}/Er{sup 3+} NPs has been achieved by doping Al{sup 3+} ions under 980 nm excitation. Compared to the aluminum-free KLaF{sub 4}:Yb{sup 3+}/Er{sup 3+} NPs sample, the UC fluorescence intensities of the green and red emissions of NPs doped with 10 at.% Al{sup 3+} ions were significantly enhanced by 5.9 and 7.3 times, respectively. Longer lifetimes of the doped samples were observed for the {sup 4}S{sub 3/2} state and {sup 4}F{sub 9/2} state. The underlying reason for the UC enhancement by doping Al{sup 3+} ions was mainly ascribed to distortion of the local symmetry around Er{sup 3+} ions and adsorption reduction of organic ligands on the surface of NPs. In addition, the influence of doping Al{sup 3+} ions on the structure and morphology of the NPs samples was also discussed. (orig.)

Emission properties of hydrothermal Yb3+, Er3+ and Yb3+, Tm3+-codoped Lu2O3 nanorods: upconversion, cathodoluminescence and assessment of waveguide behavior

International Nuclear Information System (INIS)

Barrera, Elixir William; Pujol, MarIa Cinta; DIaz, Francesc; Choi, Soo Bong; Rotermund, Fabian; Park, Kyung Ho; Jeong, Mun Seok; Cascales, Concepcion

2011-01-01

Yb 3+ and Ln 3+ (Ln 3+ = Er 3+ or Tm 3+ ) codoped Lu 2 O 3 nanorods with cubic Ia3-bar symmetry have been prepared by low temperature hydrothermal procedures, and their luminescence properties and waveguide behavior analyzed by means of scanning near-field optical microscopy (SNOM). Room temperature upconversion (UC) under excitation at 980 nm and cathodoluminescence (CL) spectra were studied as a function of the Yb + concentration in the prepared nanorods. UC spectra revealed the strong development of Er 3+4 F 9/2 → 4I 15/2 (red) and Tm 3+1 G 4 → 3 H 6 (blue) bands, which became the pre-eminent and even unique emissions for corresponding nanorods with the higher Yb 3+ concentration. Favored by the presence of large phonons in current nanorods, UC mechanisms that privilege the population of 4 F 9/2 and 1 G 4 emitting levels through phonon-assisted energy transfer and non-radiative relaxations account for these observed UC luminescence features. CL spectra show much more moderate development of the intensity ratio between the Er 3+4 F 9/2 → 4 I 15/2 (red) and 2 H 11/2 , 4 S 3/2 → 4 I 15/2 (green) emissions with the increase in the Yb 3+ content, while for Yb 3+ , Tm 3+ -codoped Lu 2 O 3 nanorods the dominant CL emission is Tm 3+1 D 2 → 3 F 4 (deep-blue). Uniform light emission along Yb 3+ , Er 3+ -codoped Lu 2 O 3 rods has been observed by using SNOM photoluminescence images; however, the rods seem to be too thin for propagation of light.

Structure and thermal expansion of Lu2O3 and Yb2O3 up to the melting points

Science.gov (United States)

Pavlik, Alfred; Ushakov, Sergey V.; Navrotsky, Alexandra; Benmore, Chris J.; Weber, Richard J. K.

2017-11-01

Knowledge of thermal expansion and high temperature phase transformations is essential for prediction and interpretation of materials behavior under the extreme conditions of high temperature and intense radiation encountered in nuclear reactors. Structure and thermal expansion of Lu2O3 and Yb2O3 were studied in oxygen and argon atmospheres up to their melting temperatures using synchrotron X-ray diffraction on laser heated levitated samples. Both oxides retained the cubic bixbyite C-type structure in oxygen and argon to melting. In contrast to fluorite-type structures, the increase in the unit cell parameter of Yb2O3 and Lu2O3 with temperature is linear within experimental error from room temperature to the melting point, with mean thermal expansion coefficients (8.5 ± 0.6) · 10-6 K-1 and (7.7 ± 0.6) · 10-6 K-1, respectively. There is no indication of a superionic (Bredig) transition in the C-type structure or of a previously suggested Yb2O3 phase transformation to hexagonal phase prior to melting.

Color tunability in green, red and infra-red upconversion emission in Tm{sup 3+}/Yb{sup 3+}/Ho{sup 3+} co-doped CeO{sub 2} with potential application for improvement of efficiency in solar cells

Energy Technology Data Exchange (ETDEWEB)

Carvalho, Luiz G.A.; Rocha, Leonardo A.; Buarque, Juliana M.M. [Laboratório de Materiais Inorgânicos Fotoluminescentes e Polímeros Biodegradáveis (LAFOP), Grupo de Pesquisa em Química de Materiais – (GPQM), Departamento de Ciências Naturais, Universidade Federal de São João Del Rei, Campus Dom Bosco, Praça Dom Helvécio, 74, 36301-160 São João Del Rei, MG (Brazil); Gonçalves, Rogéria Rocha [Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, USP, Av. Bandeirantes, 3900, 14040-901 Ribeirão Preto, SP (Brazil); Nascimento Jr, Clébio S. [Laboratório de Química Teórica e Computacional – (LQTC), Departamento de Ciências Naturais, Universidade Federal de São João del-Rei, Campus Dom Bosco, Praça Dom Helvécio, 74, 36301-160 São João del-Rei, MG (Brazil); and others

2015-03-15

The preparation of Tm{sup 3+}/Yb{sup 3+}/Ho{sup 3+} co-doped CeO{sub 2} prepared by the precipitation method using ammonium hydroxide as a precursor is presented. By X-ray diffraction the materials show the phase-type of fluorite structure and the crystallite sizes were calculated by the Scherrer's equation. No other phase was observed evincing that the rare earth ions were inserted into the fluorite phase as substitutional or interstitial dopants. The microstrain calculated by the Williamson–Hall method do not show significant changes in their values, indicating that the inclusion of rare earths does not causes structural changes in the CeO{sub 2} used as a host matrix. All material showed intense upconversion emission at red and green region under excitation with diode laser at 980 nm. The color of emission changes from green to red with increasing excitation power pump. The materials showed suitable photoluminescent properties for applications as a laser source, solar cells, and great emitter at 800 nm. - Highlights: • Tm{sup 3+}/Yb{sup 3+}/Ho{sup 3+} co-doped CeO{sub 2} prepared by the simple way. • Intense upconversion emission regions and the tunability of emission color by the laser power pump. • The materials showed suitable photoluminescent properties for different applications.

Preparation and spectroscopic properties of Yb-doped and Yb-Al-codoped high silica glasses

International Nuclear Information System (INIS)

Qiao Yanbo; Wen Lei; Wu Botao; Ren Jinjun; Chen Danping; Qiu Jianrong

2008-01-01

Yb-doped and Yb-Al-codoped high silica glasses have been prepared by sintering nanoporous glasses. The absorption, fluorescent spectra and fluorescent lifetimes have been measured and the emission cross-section and minimum pump intensities were calculated. Codoping aluminum ions enhanced the fluorescence intensity of Yb-doped high silica glass obviously. The emission cross-sections of Yb-doped and Yb-Al-codoped high silica glasses were 0.65 and 0.82 pm 2 , respectively. The results show that Yb-Al-codoped high silica glass has better spectroscopic properties for a laser material. The study of high silica glass doped with ytterbium is helpful for its application in Yb laser systems, especially for high-power and high-repetition lasers

White light emission and effect of annealing on the Ho3+–Yb3+ codoped BaCa2Al8O15 phosphor

International Nuclear Information System (INIS)

Kumari, Astha; Rai, Vineet Kumar

2015-01-01

Graphical abstract: The upconversion emission spectra of the Ho 3+ /Yb 3+ doped/codoped BaCa 2 Al 8 O 15 phosphors with different doping concentrations of Ho 3+ /Yb 3+ ions along with UC emission spectrum of the white light emitting phosphor annealed at 800 °C. - Highlights: • BaCa 2 Al 8 O 15 phosphors codoped with Ho 3+ –Yb 3+ have been prepared by combustion method. • Phosphor annealed at 800 °C, illuminate an intense white light upon NIR excitation. • The sample annealed at higher temperatures emits in the pure green region. • The colour emitted persists in the white region even at high pump power density. • Developed phosphor is suitable for making upconverters and WLEDs. - Abstract: The BaCa 2 Al 8 O 15 (BCAO) phosphors codoped with suitable Ho 3+ –Yb 3+ dopant concentration prepared by combustion method illuminate an intense white light upon near infrared diode laser excitation. The structural analysis of the phosphors and the detection of impurity contents have been performed by using the X-Ray Diffraction, FESEM and FTIR analysis. The purity of white light emitted from the sample has been confirmed by the CIE chromaticity diagram. Also, the white light emitted from the sample persists with the variation of pump power density. The phosphors emit upconversion (UC) emission bands in the blue, green and red region (three primary colours required for white light emission) along with one more band in the near infrared region of the electromagnetic spectrum. On annealing the white light emitting sample at higher temperatures, the sample starts to emit green colour and also the intensity of green and red UC emission bands get enhanced largely.

Structural and electrical properties of sputtering power and gas pressure on Ti-dope In2O3 transparent conductive films by RF magnetron sputtering

Science.gov (United States)

Chaoumead, Accarat; Joo, Bong-Hyun; Kwak, Dong-Joo; Sung, Youl-Moon

2013-06-01

Transparent conductive titanium-doped indium oxide (ITiO) films were deposited on Corning glass substrates by RF magnetron sputtering method. The effects of RF sputtering power and Ar gas pressure on the structural and electrical properties of the films were investigated experimentally, using a 2.5 wt% TiO2-doped In2O3 target. The deposition rate was in the range of around 20-60 nm/min under the experimental conditions of 5-20 mTorr of gas pressure and 220-350 W of RF power. The lowest resistivity of 1.2 × 10-4 Ω cm, the average optical transmittance of 75%, the high hall mobility of 47.03 cm2/V s and the relatively low carrier concentration of 1.15E+21 cm-3 were obtained for the ITiO film, prepared at RF power of 300 W and Ar gas pressure of 15 mTorr. This resistivity of 1.2 × 10-4 Ω cm is low enough as a transparent conducting layer in various electro-optical devices and it is comparable with that of ITO or ZnO:Al conducting layer.

Epitaxial Sb-doped SnO_2 and Sn-doped In_2O_3 transparent conducting oxide contacts on GaN-based light emitting diodes

International Nuclear Information System (INIS)

Tsai, Min-Ying; Bierwagen, Oliver; Speck, James S.

2016-01-01

We demonstrate the growth of epitaxial (100)-oriented, rutile Sb-doped SnO_2 (ATO) and (111)-oriented, cubic Sn-doped In_2O_3 (ITO) transparent conducting oxide (TCO) contacts on top of an InGaN/GaN(0001) light emitting diode (LED) by plasma-assisted molecular beam epitaxy (PAMBE). Both oxides form rotational domains. The in-plane epitaxial alignment of the two ITO(111) rotational domains to the GaN(0001) was: GaN [21-10]|| ITO_D_o_m_a_i_n_1[‐ 211]|| ITO_D_o_m_a_i_n_2[‐ 1‐12]. A growth temperature as low as 600 °C was necessary to realize a low contact resistance between ATO and the top p-GaN layer of the LED but resulted in non-optimal resistivity (3.4 × 10"− "3 Ω cm) of the ATO. The current–voltage characteristics of a processed LED, however, were comparable to that of a reference LED with a standard electron-beam evaporated ITO top contact. At short wavelengths, the optical absorption of ATO was lower than that of ITO, which is beneficial even for blue LEDs. Higher PAMBE growth temperatures resulted in lower resistive ATO but higher contact resistance to the GaN, likely by the formation of an insulating Ga_2O_3 interface layer. The ITO contact grown by PAMBE at 600 °C showed extremely low resistivity (10"−"4 Ω cm) and high crystalline and morphological quality. These proof-of-principle results may lead to the development of epitaxial TCO contacts with low resistivity, well-defined interfaces to the p-GaN to help minimize contact losses, and enable further epitaxy on top of the TCO. - Highlights: • Plasma-assisted molecular beam epitaxy of SnO_2:Sb (ATO) and In_2O_3:Sn (ITO) contacts • Working light emitting diodes processed with the ATO contact on the top p-GaN layer • Low growth temperature ensures low contact resistance (limiting interface reaction). • ITO showed significantly better structural and transport properties than ATO. • ATO showed higher optical transmission at short wavelengths than ITO.

A crystal chemistry approach for high-power ytterbium doped solid-state lasers: diffusion-bonded crystals and new crystalline hosts

International Nuclear Information System (INIS)

Gaume, R.

2002-11-01

This work deals with ytterbium based crystals for high-power laser applications. In particular, we focus our interest in reducing crystal heating and its consequences during laser operation following two different ways. First, we review the specific properties of ytterbium doped solid-state lasers in order to define a figure-of-merit which gives the evaluation of laser performances, thermo-mechanical and thermo-optical properties. Bearing in mind this analysis, we propose a set of theoretical tools, based on the crystallographic structure of the crystal and its chemical composition, to predict thermo-mechanical and optical potentials. This approach, used for the seek of new Yb 3+ -doped materials for high-power laser applications, shows that simple oxides containing rare-earths are favorable. Therefore, the spectroscopic properties of six new materials Yb 3+ :GdVO 4 , Yb 3+ :GdAlO 3 , Yb 3+ :Gd 2 O 3 , Yb 3+ :Sc 2 SiO 5 , Yb 3+ :CaSc 2 O 4 and Yb 3+ :SrSc 2 O 4 are described. The second aspect developed in this work deals with thermal properties enhancement of already well characterized laser materials. Two different ways are explored: a) elaboration by diffusion bonding of end-caps lasers with undoped crystals (composite crystals). Thus, different composites were obtained and a fairly lowering of thermal lensing effect was observed during laser operation. b) strengthening of crystalline structures by ionic substitution of one of its constituents. We demonstrate how crystal growth ability can be improved by a cationic substitution in the case of Yb 3+ :BOYS, a largely-tunable laser material which is of great interest for femtosecond pulses generation. (author)

Anatase phase stability and doping concentration dependent refractivity in codoped transparent conducting TiO2 films

International Nuclear Information System (INIS)

Chen, T L; Furubayashi, Y; Hirose, Y; Hitosugi, T; Shimada, T; Hasegawa, T

2007-01-01

Nb 0.06 Sn x Ti 0.94-x O 2 (x ≤ 0.3) thin films were grown by a pulsed-laser deposition method with varying Sn concentration. Through a combinatorial technique, we find that Sn concentration can reach a maximum of about x = 0.3 while maintaining the stable anatase phase and epitaxy. A doping concentration dependence of the refractivity is revealed, in which refractivity reduction at a wavelength of λ = 500 nm is estimated to be 12.4% for Nb 0.06 Sn 0.3 Ti 0.64 O 2 thin film. Sn doping induced band-gap blue shift can be contributed to the mixing of extended Sn 5s orbitals with the conduction band of TiO 2 . Low resistivity on the order of 10 -4 Ω cm at room temperature and high internal transmittance of more than 95% in the visible light region are exhibited for Nb 0.06 Sn x Ti 0.94-x O 2 thin films (x ≤ 0.2). Optical and transport analyses demonstrate that doping Sn into Nb 0.06 Ti 0.94 O 2 can reduce the refractivity while maintaining low resistivity and high transparency

Tuning from green to red the upconversion emission of Y{sub 2}O{sub 3}:Er{sup 3+}-Yb{sup 3+} nanophosphors

Energy Technology Data Exchange (ETDEWEB)

Diaz-Torres, L.A. [Centro de Investigaciones en Optica, Grupo de Espectroscopia de Materiales Avanzados y Nanoestructurados (GEMANA), A. P. 1-948, Leon, GTO (Mexico); Salas, P.; Resendiz-L, E.; Rodriguez-Gonzalez, C. [Universidad Nacional Autonoma de Mexico, Centro de Fisica Aplicada y Tecnologia Avanzada, Apartado Postal 1-1010, Queretaro, QRO (Mexico); Oliva, J. [Conacyt-Facultad Ciencias Quimicas Universidad Autonoma de Coahuila, Saltillo, Coahuila (Mexico); Meza, O. [Benemerita Universidad Autonoma de Puebla, Instituto de Fisica, A.P. J-48, Centro Historico, PUE (Mexico)

2017-01-15

In this work, the structural, morphological and luminescent properties of Y{sub 2}O{sub 3} nanophosphors doped with Er{sup 3+} (1 mol%) and different Yb{sup 3+} concentrations (2-12 mol%) have been studied. Those nanophosphors were synthesized using a simple hydrothermal method. XRD analysis indicates that all the samples presented a pure cubic phase even for Yb concentrations as high as 12 mol%. In addition, SEM images show nanoparticles with quasi-spherical shapes with average sizes in the range of 300-340 nm. Photoluminescence measurements obtained after excitation at 967 nm revealed that our samples have strong green (563 nm) and red emissions (660 nm) corresponding to {sup 2}H{sub 11/2} + {sup 4}S{sub 3/2} → {sup 4}I{sub 15/2} and {sup 4}F{sub 9/2} → {sup 4}I{sub 15/2} transitions of Er{sup 3+} ions, respectively. We also observed that the green band is quenched and the red emission enhanced as the Yb concentration increases. In consequence, the CIE coordinates changed from (0.35, 0.64) in the green region to (0.59, 0.39) in the red region. Thus, the tuning properties of Y{sub 2}O{sub 3} nanophosphors suggest that they are good candidates for applications in lighting. (orig.)

Near-infrared quantum cutting in Yb3+ ion doped strontium vanadate

Science.gov (United States)

Sawala, N. S.; Bajaj, N. S.; Omanwar, S. K.

2016-05-01

The materials Sr3-x(VO4)2:xYb were successfully synthesized by co-precipitation method varying the concentration of Yb3+ ions from 0 to 0.06 mol. It was characterize by powder X-ray powder diffraction (XRD) and surface morphology was studied by scanning electronic microscope (SEM). The photoluminescence (PL) properties were studied by spectrophotometers in near infra red (NIR) and ultra violet visible (UV-VIS) region. The Yb3+ ion doped tristrontium vanadate (Sr3(VO4)2) phosphors that can convert a photon of UV region (349 nm) into photons of NIR region (978, 996 and 1026 nm). Hence this phosphor could be used as a quantum cutting (QC) luminescent convertor in front of crystalline silicon solar cell (c-Si) panels to reduce thermalization loss due to spectral mismatch of the solar cells. The theoretical value of quantum efficiency (QE) was calculated from steady time decay measurement and the maximum efficiency approached up to 144.43%. The Sr(3-x) (VO4)2:xYb can be potentiality used for betterment of photovoltaic (PV) technology.

NIR to visible frequency upconversion in Er3+ and Yb3+ codoped ZrO2 phosphor

International Nuclear Information System (INIS)

Singh, Vijay; Kim, Sang Hwan; Rai, Vineet Kumar; Al-Shamery, Katharina; Haase, Markus

2013-01-01

The ZrO 2 :Er 3+ codoped with Yb 3+ phosphor powders have been prepared by the urea combustion route. Formation of the compounds ZrO 2 :Er 3+ and ZrO 2 :Er 3+ , Yb 3+ was confirmed by XRD. The frequency upconversion emissions in the green and red regions upon excitation with a CW diode laser at ∝978 nm are reported. Codoping with Yb 3+ enhances the emission intensities of the triply ionized erbium in the green and red spectral regions by about ∝130 and ∝820 times respectively. The emission properties of the ZrO 2 :Er 3+ phosphor powders are discussed on the basis of excited state absorption, energy transfer, and cross-relaxation energy transfer mechanisms. (orig.)

Spectroscopic investigation of zinc tellurite glasses doped with Yb3 + and Er3 + ions

Science.gov (United States)

Bilir, Gökhan; Kaya, Ayfer; Cinkaya, Hatun; Eryürek, Gönül

2016-08-01

This paper presents a detailed spectroscopic investigation of zinc tellurite glasses with the compositions (0.80 - x - y) TeO2 + (0.20) ZnO + xEr2O3 + yYb2O3 (x = 0, y = 0; x = 0.004, y = 0; x = 0, y = 0.05 and x = 0.004, y = 0.05 per moles). The samples were synthesized by the conventional melt quenching method. The optical absorption and emission measurements were conducted at room temperature to determine the spectral properties of lanthanides doped zinc tellurite glasses and, to study the energy transfer processes between dopant lanthanide ions. The band gap energies for both direct and indirect possible transitions and the Urbach energies were measured from the absorption spectra. The absorption spectra of the samples were analyzed by using the Judd-Ofelt approach. The effect of the ytterbium ions on the emission properties of erbium ions was investigated and the energy transfer processes between dopant ions were studied by measuring the up-conversion emission properties of the materials. The color quality parameters of obtained visible up-conversion emission were also determined as well as possibility of using the Er3 + glasses as erbium doped fiber amplifiers at 1.55 μm in infrared emission region.

Polarized spectroscopic properties of Er{sup 3+}:Gd{sub 2}SiO{sub 5} crystal and evaluation of Er{sup 3+}:Yb{sup 3+}:Gd{sub 2}SiO{sub 5} crystal as a 1.55 μm laser medium

Energy Technology Data Exchange (ETDEWEB)

Wang, H. [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); University of Chinese Academy of Sciences, Beijing 100039 (China); Huang, J.H.; Gong, X.H.; Chen, Y.J.; Lin, Y.F.; Luo, Z.D. [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Huang, Y.D., E-mail: huyd@fjirsm.ac.cn [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China)

2016-10-01

An Er{sup 3+}-doped Gd{sub 2}SiO{sub 5} single crystal with high optical quality has been grown by the Czochralski method. Polarized absorption and fluorescence spectra and fluorescence lifetime of the crystal were measured at room temperature. Intensity parameters, spontaneous emission probabilities, fluorescence branching ratios, and radiative lifetimes were estimated on the basis of the Judd–Ofelt theory. Besides, potentiality of 1.55 μm laser emission in an Er{sup 3+}–Yb{sup 3+} co-doped Gd{sub 2}SiO{sub 5} crystal was evaluated.

Optical properties of silica-coated Y2O3:Er,Yb nanoparticles in the presence of polyvinylpyrrolidone

International Nuclear Information System (INIS)

Fujii, Kunio; Kitamoto, Yoshitaka; Hara, Masahiko; Odawara, Osamu; Wada, Hiroyuki

2014-01-01

The optical properties of polyvinylpyrrolidone (PVP)-adsorbed and silica-coated Y 2 O 3 :Er,Yb nanoparticles produced by using PVP were studied for potential bio-applications of upconversion nanoparticles. We utilized PVP to better disperse Y 2 O 3 :Er,Yb nanoparticles in solution and to prepare silica-coated Y 2 O 3 :Er,Yb nanoparticles. The fluorescent intensity of PVP-adsorbed Y 2 O 3 :Er,Yb nanoparticles was 1.25 times higher than non-adsorbed Y 2 O 3 :Er,Yb nanoparticles, which was probably due to surface defects in Y 2 O 3 :Er,Yb nanoparticles being covered by the PVP. However, the fluorescent intensity of silica-coated Y 2 O 3 :Er,Yb nanoparticles decreased as silica layer thickness increased. This could be ascribed to the higher vibrational energy of PVP than that of the silica structure. Therefore, the optimum silica layer thickness is important in bio-applications to avoid deterioration of the optical properties of Y 2 O 3 :Er,Yb nanoparticles. - Highlights: • We prepared the silica-coated upconversion nanoparticles by using PVP. • We showed that PVP played an important role in coating nanoparticles. • PL intensity of silica-coated nanoparticles decreased as silica layer thickness increased

Oxygen plasma effects on zero resistance behavior of Yb,Er-doped YBCO (123) based superconductors

Energy Technology Data Exchange (ETDEWEB)

Schaefer, Helmut; Rathmann, Dirk [Department of Physics, Biophysics, and Photosynthesis, Freie Universitaet Berlin (Germany); Banko, Franziska; Steinhart, Martin [Physical Chemistry, Institute of Chemistry of New Materials, University of Osnabrueck (Germany); Nordmann, Joerg; Voss, Benjamin [Inorganic Chemistry, Institute of Chemistry of New Materials, University of Osnabrueck (Germany); Walder, Lorenz [Organic Chemistry, Molecular Electrochemistry, Institute of Chemistry of New Materials, University of Osnabrueck (Germany)

2014-08-15

Rare-earth doped YBa{sub 2}Cu{sub 3}O{sub 7-δ} samples were synthesized starting from the corresponding oxides Y{sub 2}O{sub 3}, Yb{sub 2}O{sub 3}, Er{sub 2}O{sub 3}, CuO as well as Ba(OH){sub 2} by heating to 950 C under air. The doping concentrations were adjusted to 15 % Yb, 7 % Er and 20 % Yb, 15 % Er, respectively, with respect to the yttrium content. The orthogonal phased (123) YBCO ceramics were exposed to an oxygen plasma for 140 and 380 min. Zero resistance temperature (T{sub c,0}) was determined by measuring the resistivity-temperature dependence using a classical four point measurement approach. Under optimal conditions with respect to the material composition and the oxygen treatment an unusual high zero resistance temperature of 97.5 K (T{sub c,onset} ∼ 101 K) was achieved. This represents an increase of T{sub c,0} by 7.5 K. The oxygen treatment could not be monitored by IR spectroscopy, X-ray fluorescence spectroscopy, and X-ray powder diffraction. The results showed good reproducibility. (Copyright copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Epitaxial growth and magnetic properties of ultraviolet transparent Ga2O3/(Ga1-xFex)2O3 multilayer thin films.

Science.gov (United States)

Guo, Daoyou; An, Yuehua; Cui, Wei; Zhi, Yusong; Zhao, Xiaolong; Lei, Ming; Li, Linghong; Li, Peigang; Wu, Zhenping; Tang, Weihua

2016-04-28

Multilayer thin films based on the ferromagnetic and ultraviolet transparent semiconductors may be interesting because their magnetic/electronic/photonic properties can be manipulated by the high energy photons. Herein, the Ga2O3/(Ga1-xFex)2O3 multilayer epitaxial thin films were obtained by alternating depositing of wide band gap Ga2O3 layer and Fe ultrathin layer due to inter diffusion between two layers at high temperature using the laser molecular beam epitaxy technique. The multilayer films exhibits a preferred growth orientation of crystal plane, and the crystal lattice expands as Fe replaces Ga site. Fe ions with a mixed valence of Fe(2+) and Fe(3+) are stratified distributed in the film and exhibit obvious agglomerated areas. The multilayer films only show a sharp absorption edge at about 250 nm, indicating a high transparency for ultraviolet light. What's more, the Ga2O3/(Ga1-xFex)2O3 multilayer epitaxial thin films also exhibits room temperature ferromagnetism deriving from the Fe doping Ga2O3.

1.8 μm luminescent properties and energy transfer of Yb{sup 3+}/Tm{sup 3+} co-doped α-NaYF{sub 4} single crystals

Energy Technology Data Exchange (ETDEWEB)

Feng, Zhigang [Key Laboratory of Photo-electronic Materials, Ningbo University, Ningbo, Zhejiang, 315211 (China); Xia, Haiping, E-mail: hpxcm@nbu.edu.cn [Key Laboratory of Photo-electronic Materials, Ningbo University, Ningbo, Zhejiang, 315211 (China); Wang, Cheng; Zhang, Zhixiong; Jiang, Dongsheng; Zhang, Jian; He, Shinan; Tang, Qingyang; Sheng, Qiguo; Gu, Xuemei; Zhang, Yuepin [Key Laboratory of Photo-electronic Materials, Ningbo University, Ningbo, Zhejiang, 315211 (China); Chen, Baojiu [Department of Physics, Dalian Maritime University, Dalian, Liaoning Province, 116026 (China); Jiang, Haochuan, E-mail: jianghaochuan@nimte.ac.cn [Ningbo Institute of Materials Technology and Engineering, The Chinese Academy of Sciences, Ningbo, Zhejiang, 315211 (China)

2016-09-25

This paper reports on successful preparation of α-NaYF{sub 4} single crystals co-doped with ∼1.9 mol% Tm{sup 3+} and various concentrations (3.85 mol%, 7.69 mol%, 11.54 mol%, 15.38 mol%) of Yb{sup 3+} by using a flux-Bridgman method. The fluorescence decay curve was measured to investigate the luminescent properties of the Yb{sup 3+}/Tm{sup 3+} co-doped α-NaYF{sub 4}, and the energy transfer process from Yb{sup 3+} to Tm{sup 3+}; the J-O intensity parameters of Tm{sup 3+} were further calculated and analyzed according to the absorption spectra. Results show that, an intense 1.8 μm emission was achieved with Yb{sup 3+} as sensitizer for Tm{sup 3+} in the α-NaYF{sub 4} single crystal under the excitation of 980 nm LD (Laser Diode) because of the strong energy transfer from Yb{sup 3+} to Tm{sup 3+}. The maximum emission intensity at 1.8 μm is obtained at about 15.38 mol% doping concentration of Yb{sup 3+} when the concentration of Tm{sup 3+} ions is fixed at ∼1.90 mol% in the current research. Moreover, the calculated maximum value of emission cross section at 1.8 μm is 1.63 × 10{sup −20} cm{sup 2} for 3.85 mol% Yb{sup 3+}/1.9 mol% Tm{sup 3+} sample, and the obtained energy transfer rate (W{sub ET}) and energy transfer efficiency (η) are 1543 s{sup −1} and 83.8%, respectively. Our analysis of the fluorescence dynamics indicates that electric dipole-dipole interaction is dominant for the energy transfer from Yb{sup 3+} ions to Tm{sup 3+} ions by using Inokuti-Hirayama’s model. - Highlights: • The Tm{sup 3+}/Yb{sup 3+} co-doped α-NaYF{sub 4} single crystals were grown by Bridgman method. • The 1.8 μm emission intensity is obtained at 15.38 mol% Yb{sup 3+}/1.90 mol% Tm{sup 3+} sample. • The maximum value of emission cross section at 1.8 μm is 1.63 × 10{sup −20} cm{sup 2}. • The energy transfer rate is 1543 s{sup −1} and energy transfer efficiency is 83.8%. • The physical mechanism for energy transfer from Yb{sup 3+} to Tm{sup 3+} ions

Nd{sup 3+}-doped TeO{sub 2}-Bi{sub 2}O{sub 3}-ZnO transparent glass ceramics for laser application at 1.06 μm

Energy Technology Data Exchange (ETDEWEB)

Hu, Xiaolin; Luo, Zhiwei; Liu, Taoyong; Lu, Anxian [Central South of University, School of Materials Science and Engineering, Changsha (China)

2017-04-15

The high crystallinity transparent glass ceramics based on Nd{sup 3+}-doped 70TeO{sub 2}-15Bi{sub 2}O{sub 3}-15ZnO (TBZ) compositions were successfully prepared by two-step heat treatment process. The effects of Nd{sub 2}O{sub 3} content on the thermal, structural, mechanical, and optical properties of TBZ glass ceramics were studied. The incorporation of Nd{sub 2}O{sub 3} enhanced the crystallization tendency in the matrix glass composition. The crystal phase and morphology of Bi{sub 2}Te{sub 4}O{sub 11} in the glass ceramics were confirmed by X-ray diffraction and field emission scanning electron microscopy. Due to precipitate more crystal phase, the hardness values increased from 3.21 to 3.66 GPa. Eight absorption peaks were observed from 400 to 900 nm and three emission bands appeared in the range of 850-1400 nm. With the increasing of Nd{sub 2}O{sub 3} content from 0.5 to 2.5 wt%, the intensity of absorption peaks enhanced and the emission intensity increased up to 1.0 wt% and then fell down for further dopant concentration. The fluorescence decay lifetime decreased rapidly starting from 1.5 wt% Nd{sub 2}O{sub 3} content due to the obvious energy migration among Nd{sup 3+}. According to the extreme strong emission band around 1062 nm and the optimum Nd{sub 2}O{sub 3} content (1.0 wt%), N10 glass ceramic was considered as a potential material for 1.06 μm laser applications. (orig.)

Cluster self-organization of germanate systems: suprapolyhedral precursor clusters and self-assembly of K2Nd4Ge4O13(OH)4, K2YbGe4O10(OH), K2Sc2Ge2O7(OH)2, and KScGe2O6(PYR)

International Nuclear Information System (INIS)

Ilyushin, G.D.; Dem'yanets, L.N.

2008-01-01

One performed the computerized (the TOPOS 4.0 software package) geometric and topological analyses of all known types of K, TR-germanates (TR = La-Lu, Y, Sc, In). The skeleton structure are shown as three-dimensional 3D, K, TR, Ge-patterns (graphs) with remote oxygen atoms. TR 4 3 3 4 3 3 + T 4 3 4 3, K 2 YbGe 4 O 14 (OH) pattern, TR 6 6 3 6 + T1 6 8 6 + T2 3 6 8, K 2 Sc 2 Ge 2 O 7 (OH) 2 , TR 6 4 6 4 + T 6 4 6 and KScGe 2 O 6 - TR 6 6 3 6 3 4 + T1 6 3 6 + T2 6 4 3 patterns served as crystal-forming 2D TR,Ge-patterns for K 2 Nd 4 Ge 4 O 13 (OH) 4 . One performed the 3D-simulation of the mechanism of self-arrangement of the crystalline structures: cluster-precursor - parent chain - microlayer - microskeleton (super-precursor). Within K 2 Nd 4 Ge 4 O 13 (OH) 4 , K 2 Sc 2 Ge 2 O 7 (OH) 2 and KScGe 2 O 6 one identified the invariant type of the cyclic hexapolyhedral cluster-precursor consisting of TR-octahedrons linked by diorthogroups stabilized by K atoms. For K 2 Nd 4 Ge 4 O 13 (OH) 4 one determined the type of the cyclic tetrapolyhedral cluster-precursor consisting of TR-octavertices linked by tetrahedrons. The cluster CN within the layer just for KScGe 2 O 6 water-free germanate (the PYR pyroxene analog) is equal to 6 (the maximum possible value), while in the rest OH-containing germanates it constitutes 4. One studied the formation mechanism of Ge-radicals in the form of Ge 2 O 7 and Ge 4 O 13 groupings, GeO 3 chain and the tubular structure consisting of Ge 8 O 20 fixed cyclic groupings [ru

Crystal growth, optical properties, and laser operation of Yb3+-doped NYW single crystal

Science.gov (United States)

Cheng, Y.; Xu, X. D.; Yang, X. B.; Xin, Z.; Cao, D. H.; Xu, J.

2009-11-01

Laser crystal Yb3+-doped NaY(WO4)2 (Yb:NYW) with excellent quality has been grown by Czochralski technique. The rocking curves from (400) plane of as-grown Yb:NYW crystal was measured and the full-width value at half-maximum was 19.92″. The effective segregation coefficients were measured by the X-ray fluorescence method. The polarized absorption spectra and the fluorescence spectra of Yb:NYW crystal were measured at room temperature. The fluorescence decay lifetime of Yb3+ ion in NYW crystal has been investigated. The spectroscopic parameters of Yb:NYW crystal are calculated and compared with those of Yb:YAG crystal. A continuous wave output power of 3.06 W at 1031 nm was obtained with a slope efficiency of 42% by use of diode pumping.

Tunable multicolor and white-light upconversion luminescence in Yb3+/Tm3+/Ho3+ tri-doped NaYF4 micro-crystals.

Science.gov (United States)

Lin, Hao; Xu, Dekang; Teng, Dongdong; Yang, Shenghong; Zhang, Yueli

2015-09-01

NaYF4 micro-crystals with various concentrations of Yb(3+) /Tm(3+) /Ho(3+) were prepared successfully via a simple and reproducible hydrothermal route using EDTA as the chelating agent. Their phase structure and surface morphology were studied using powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD patterns revealed that all the samples were pure hexagonal phase NaYF4. SEM images showed that Yb(3+)/Tm(3+)/Ho(3+) tri-doped NaYF4 were hexagonal micro-prisms. Upconversion photoluminescence spectra of Yb(3+)/Tm(3+)/Ho(3+) tri-doped NaYF4 micro-crystals with various dopant concentrations under 980 nm excitation with a 665 mW pump power were studied. Tunable multicolor (purple, purplish blue, yellowish green, green) and white light were achieved by simply adjusting the Ho(3+) concentration in 20%Yb(3+)/1%Tm(3+)/xHo(3+) tri-doped NaYF4 micro-crystals. Furthermore, white-light emissions could be obtained using different pump powers in 20%Yb(3+)/1%Tm(3+)/1%Ho(3+) tri-doped NaYF4 micro-crystals at 980 nm excitation. The pump power-dependent intensity relationship was studied and relevant energy transfer processes were discussed in detail. The results suggest that Yb(3+)/Tm(3+) Ho(3+) tri-doped NaYF4 micro-crystals have potential applications in optoelectronic devices such as photovoltaic, plasma display panel and white-light-emitting diodes. Copyright © 2014 John Wiley & Sons, Ltd.

Structural and photoluminescence study of Er-Yb codoped nanocrystalline ZrO{sub 2}-B{sub 2}O{sub 3} solid solution

Energy Technology Data Exchange (ETDEWEB)

Salas, P. [Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, A.P. 1-1010, Queretaro 76000 (Mexico); Borja-Urby, R. [Grupo de Espectroscopia de Materiales Avanzados y nanoestructurados (EMANA), Centro de Investigaciones en Optica, A. C., Loma del Bosque 115, Col. Lomas del Campestre, C.P. 37150 Leon, Gto. (Mexico); Diaz-Torres, L.A., E-mail: ditlacio@cio.mx [Grupo de Espectroscopia de Materiales Avanzados y nanoestructurados (EMANA), Centro de Investigaciones en Optica, A. C., Loma del Bosque 115, Col. Lomas del Campestre, C.P. 37150 Leon, Gto. (Mexico); Rodriguez, G. [Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, A.P. 1-1010, Queretaro 76000 (Mexico); Vega, M. [Centro de Geociencias, Universidad Nacional Autonoma de Mexico, A.P. 1-1010, Queretaro 76000 (Mexico); Angeles-Chavez, C. [Instituto Mexicano del Petroleo, Programa de Ingenieria Molecular, Eje Central Lazaro Cardenas 152, A.P. 14-805, 07730 Mexico, DF (Mexico)

2012-09-20

Codoped Er{sup 3+} and Yb{sup 3+} nanocrystalline ZrO{sub 2}-B{sub 2}O{sub 3} phosphor obtained by a modified sol-gel method is demonstrated. The addition of up to 2.5 mol% B{sub 2}O{sub 3} to nanocrystalline ZrO{sub 2}:Yb(2%), Er(1%) keep the tetragonal rare-earth stabilized ZrO{sub 2} phase; whereas higher B{sub 2}O{sub 3} content destabilize the tetragonal phase, leading to the tetragonal to monoclinic transition with no tetragonal ZrO{sub 2} phase segregation. Visible upconversion of the luminescent active ions, Er{sup 3+} and Yb{sup 3+}, depend strongly on B{sub 2}O{sub 3} content. The PL intensity is strongly quenched for high B{sub 2}O{sub 3} content due to increasing multiphonon relaxation processes related to B-O and B-O-B vibronic modes.

Studies on high-pressure reaction of Er/sub 2/O/sub 3/ or Yb/sub 2/O/sub 3/ with VO/sub 2/

Energy Technology Data Exchange (ETDEWEB)

Shin-ike, T [Osaka Dental Coll., Hirakata (Japan); Adachi, G; Shiokawa, J; Shimada, M; Koizumi, M

1980-12-01

The reaction of erbium sesquioxide (Er/sub 2/O/sub 3/) or ytterbium sesquioxide (Yb/sub 2/O/sub 3/) with vanadium dioxide (VO/sub 2/) at 1400/sup 0/C and 50 kbar and 30 kbar pressures was studied. Quadrivalent vanadium ions were reduced to the trivalent state, erbium vanadate (ErVO/sub 3/) or ytterbium vanadate (YbVO/sub 3/) being obtained. The crystal structure of ErVO/sub 3/ obtained at 50 kbar pressure was vaterite-type isostructural with ErBO/sub 3/ belonging to a hexagonal system, and that obtained at 30 kbar calcite-type belonging to a rhombohedral (pseudo-hexagonal) system. In the reaction of Yb/sub 2/O/sub 3/ with VO/sub 2/ at high pressure, a perovskite-type crystal was obtained. The electrical and magnetic properties of the vaterite- and the calcite-type ErVO/sub 3/ were studied.

Lanthanide doped BaTiO{sub 3}−SrTiO{sub 3} solid-solution phosphors: Structure, optical spectroscopy and upconverted temperature sensing behavior

Energy Technology Data Exchange (ETDEWEB)

Chen, Daqin, E-mail: dqchen@hdu.edu.cn; Xu, Wei; Zhou, Yang; Chen, Yan, E-mail: chenyan@hdu.edu.cn

2016-08-15

Lanthanide doped Ba{sub 1-x}Sr{sub x}TiO{sub 3} (x = 0–1) solid-solution phosphors were successfully prepared by a conventional solid-state reaction. Using Eu{sup 3+} dopants as the structural probe, the variation of {sup 5}D{sub 0} → {sup 7}F{sub 2}/{sup 5}D{sub 0} → {sup 7}F{sub 1} emission intensity ratio with increase of Eu{sup 3+} content and the excitation-wavelength-dependent luminescence in the Ba{sub 1-x}Sr{sub x}TiO{sub 3} sample were demonstrated to be originated from the different emission behaviors of Eu{sup 3+} in Ba{sup 2+}/Sr{sup 2+} site and Ti{sup 4+} site. Furthermore, upconversion luminescence for the Yb{sup 3+}/Er{sup 3+} co-doped Ba{sub 1-x}Sr{sub x}TiO{sub 3} samples were investigated, and it was found that the emission intensity of Yb{sup 3+}/Er{sup 3+}: Ba{sub 0.5}Sr{sub 0.5}TiO{sub 3} phosphor was about 5 and 2 times as high as those of Yb{sup 3+}/Er{sup 3+}: BaTiO{sub 3} and Yb{sup 3+}/Er{sup 3+}: SrTiO{sub 3} ones. Using the investigated Yb{sup 3+}/Er{sup 3+}: Ba{sub 0.5}Sr{sub 0.5}TiO{sub 3} solid-solution as the optical thermometric medium, the temperature sensitivity was determined to be 0.76% K{sup −1} at the temperature of 610 K based on the temperature-dependent fluorescence intensity ratio of the thermally coupled {sup 2}H{sub 11/2} and {sup 4}S{sub 3/2} emitting-states of Er{sup 3+}. - Highlights: • Lanthanide doped Ba{sub 1-x}Sr{sub x}TiO{sub 3} (x = 0–1) solid-solutions were fabricated. • Excitation-wavelength-dependent Eu{sup 3+} emissions were recorded. • Enhanced Er{sup 3+} luminescence was realized by partial substitution of Ba{sup 2+} by Sr{sup 2+}. • T-sensitive emissions of two Er{sup 3+} thermally coupled states were observed. • The upconversion phosphor exhibited a high sensitivity of 0.76% K{sup −1}.

Spectral properties of hydrothermally-grown Nd:LuAG, Yb:LuAG, and Yb:Lu{sub 2}O{sub 3} laser materials

Energy Technology Data Exchange (ETDEWEB)

Brown, David C., E-mail: DBrown@snakecreeklasers.com [Snake Creek Lasers LLC, Friendsville, PA 18818 (United States); McMillen, Colin D.; Moore, Cheryl; Kolis, Joseph W. [Department of Chemistry and Center for Optical Materials Science and Engineering Technologies, Clemson University, Clemson, SC 29634-0973 (United States); Envid, Victoria [Snake Creek Lasers LLC, Friendsville, PA 18818 (United States)

2014-04-15

We have investigated the hydrothermal growth of, and spectrally characterized, the lutetium based laser materials Nd:LuAG, Yb:LuAG, and Yb:Lu{sub 2}O{sub 3}. Absorption cross-section data are presented for Nd:LuAG at 83, 175, and 295 K. Absorption cross-section data was also obtained for Yb:LuAG at 83, 175, and 295 K; the 295 K data was used to generate emission cross-sections using the method of reciprocity. For Yb:Lu{sub 2}O{sub 3}, we present absorption cross-sections at 295 K as well as emission cross-sections derived using reciprocity. -- Highlights: • We present spectral properties for hydrothermally-grown laser crystals. • Absorption cross-section data are presented for Nd:LuAG and Yb:LuAG at 83, 175, and 295 K. • Emission cross-sections are presented for Yb:LuAG at 295 K derived by reciprocity. • We present absorption cross-sections at 295 K as well as emission cross-sections derived using reciprocity for the laser material Yb:Lu{sub 2}O{sub 3}.

Role of Gd{sup 3+} ion on downshifting and upconversion emission properties of Pr{sup 3+}, Yb{sup 3+} co-doped YNbO{sub 4} phosphor and sensitization effect of Bi{sup 3+} ion

Energy Technology Data Exchange (ETDEWEB)

Dwivedi, A.; Rai, S. B., E-mail: sbrai49@yahoo.co.in [Department of Physics, Banaras Hindu University, Varanasi 221005 (India); Mishra, Kavita [Department of Physics, University of Lucknow, Lucknow 226007 (India)

2016-07-28

Dual-mode luminescence (downshifting-DS and upconversion-UC) properties of Pr{sup 3+}/Yb{sup 3+} co-doped Y{sub 1−x}Gd{sub x}NbO{sub 4} (x = 0.0, 0.5, and 1.0) phosphors synthesized by solid state reaction technique have been explored with and without Gd{sup 3+} ion. The structural characterizations (XRD, SEM, and FTIR) confirm the pure phase of YNbO{sub 4} phosphor. Further, with the Gd{sup 3+} ion co-doping, the YNbO{sub 4} phosphors having a random shape and the large particle size are found to be transformed into nearly spherical shape particles with the reduced particle size. The optical band gaps (E{sub g}) of Y{sub 1−x}Gd{sub x}NbO{sub 4} (x = 0.00, 0.25, 0.50, and 1.00) calculated from UV-Vis-NIR measurements are ∼3.69, 4.00, 4.38, and 4.44 eV, respectively. Moreover, YNbO{sub 4} phosphor is a promising blue emitting material, whereas Y{sub 1−x−y−z}Pr{sub y}Yb{sub z}Gd{sub x}NbO{sub 4} phosphor gives intense green, blue, and red emissions via dual-mode optical processes. The broad blue emission arises due to (NbO{sub 4}){sup 3−} group of the host with λ{sub ex} = 264 nm, whereas Pr{sup 3+} doped YNbO{sub 4} phosphor gives dominant red and blue emissions along with comparatively weak green emission on excitation with λ{sub ex} = 300 nm and 491 nm. The concentration dependent variation in emission intensity at 491 nm ({sup 3}P{sub 0}→{sup 3}H{sub 4} transition) and 612 nm ({sup 1}D{sub 2}→{sup 3}H{sub 4} transition); at 612 nm ({sup 1}D{sub 2}→{sup 3}H{sub 4} transition) and 658 nm ({sup 3}P{sub 0}→{sup 3}F{sub 2} transition) of Pr{sup 3+} ion in YNbO{sub 4} phosphor with λ{sub ex} = 300 nm and 491 nm excitations, respectively, has been thoroughly explored and explained by the cross-relaxation process through different channels. The sensitization effect of Bi{sup 3+} ion co-doping on DS properties of the phosphor has also been studied. The observed DS results have been optimized by varying the

Photoelectrochemical Characterization of Sprayed alpha-Fe2O3 Thin Films : Influence of Si Doping and SnO2 Interfacial Layer

NARCIS (Netherlands)

Liang, Y.; Enache, C.S.; Van De Krol, R.

2008-01-01

a-Fe2O3 thin film photoanodes for solar water splitting were prepared by spray pyrolysis of Fe(AcAc)3. The donor density in the Fe2O3 films could be tuned between 10171020cm-3 by doping with silicon. By depositing a 5 nm SnO2 interfacial layer between the Fe2O3 films and the transparent conducting

Indium doped Cd{sub 1-x}Zn{sub x}O alloys as wide window transparent conductors

Energy Technology Data Exchange (ETDEWEB)

Zhu, Wei [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Physics, The Center for Physical Experiments, University of Science and Technology of China, Hefei, Anhui 230026 (China); Yu, Kin Man, E-mail: kinmanyu@cityu.edu.hk [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Physics and Materials Science, City University of Hong Kong, Kowloon (Hong Kong); Walukiewicz, W. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

2015-12-31

We have synthesized Indium doped Cd{sub 1-x}Zn{sub x}O alloys across the full composition range using magnetron sputtering method. The crystallographic structure of these alloys changes from rocksalt (RS) to wurtzite (WZ) when the Zn content is higher than 30%. The rocksalt phase alloys in the composition range 0 < x < 0.3 can be efficiently n-type doped, shifting the absorption edge to 3.25 eV and reducing resistivity to about 2.0 × 10{sup −4} Ω-cm. We found that In doped CdO (ICO) transmits more solar photons than commercial fluorine doped tin oxide (FTO) with comparable sheet conductivity. The infrared transmittance is further extended to longer than 1500 nm wavelengths by depositing the In doped Cd{sub 1-x}Zn{sub x}O in ~ 1% of O{sub 2}. This material has a potential for applications as a transparent conductor for silicon and multi-junction solar cells. - Highlights: • Indium doped Cd1-xZnxO alloys across the full composition range were synthesized. • Alloys change from rocksalt (RS) to wurtzite (WZ) when x is higher than 30%. • RS-Cd1-xZnxO phase can be doped with In as efficiently as CdO, achieving a low resistivity ~ 2.0 × 10{sup −4} Ω-cm. • Wide transparency window from 380 to 1200 nm • In doped CdO transmits more solar photons than commercial fluorine doped tin oxide.

Up-conversion and near infrared luminescence in Er3+/Yb3+ co-doped glass-ceramic containing MgGa2O4 nano-crystals

International Nuclear Information System (INIS)

Sun, Jiaju; Yu, Lixin; Li, Fuhai; Wei, Shuilin; Li, Songchu

2016-01-01

The MgO–Ga 2 O 3 –SiO 2 (MG-S) glasses and nanocrystalline glass-ceramics (GCs) containing MgGa 2 O 4 nanocrystals codoped with Er 3+ and Yb 3+ were prepared by a simple sol–gel method. The formation of MgGa 2 O 4 nanocrystals in the GCs was confirmed by the X-ray diffraction (XRD). Their morphology was investigated applying high-resolution transmission electron microscopy (HRTEM). Stark splitting of near infrared (NIR) and up-conversion (UC) emission implies that the Er 3+ is incorporated into MgGa 2 O 4 nanocrystals. The effect of the MgO, Ga 2 O 3 content and sintering temperature on the structure of the prepared samples was systematically studied. Under 980 nm excitation, intense UC and NIR emission (1530 nm) were observed in the MG-S GCs by efficient energy transfer from Yb 3+ to Er 3+ . The two-photon process was confirmed to be responsible for both the green and red UC emissions. - Highlights: • It is interesting that the CIE chromaticity coordinates of the several prepared CaMO 4 :Eu samples by a hydrothermal method are very close to the standard of white light.

Near-infrared photoluminescence in La{sub 0.98}AlO{sub 3}: {sub 0.02}Ln{sup 3+}(Ln = Nd/Yb) for sensitization of c-Si solar cells

Energy Technology Data Exchange (ETDEWEB)

Sawala, N. S., E-mail: nssawala@gmail.com; Koparkar, K. A.; Omanwar, S. K. [Department of Physics, SantGadge Baba Amravati University, Amravati - MH, 444602 (India); Bajaj, N. S. [Department of Physics, Toshniwal Art, Commerce and Science College, Sengoan, Hingoli - MH (India)

2016-05-06

The host matrix LaAlO{sub 3} was synthesized by conventional solid state reaction method in which the Nd{sup 3+} ions and Yb{sup 3+} ions successfully doped at 2mol% concentrations. The phase purity was confirmed by X ray powder diffraction (XRD) method. The photoluminescence (PL) properties were studied by spectrophotometer in near infra red (NIR) and ultra violet visible (UV-VIS) region. The Nd{sup 3+} ion doped LaAlO{sub 3} converts a visible (VIS) green photon (587 nm) into near infrared (NIR) photon (1070 nm) while Yb{sup 3+} ion doped converts ultra violet (UV) photon (221 nm) into NIR photon (980 nm). The La{sub 0.98}AlO{sub 3}: {sub 0.02}Ln{sup 3+}(Ln = Nd / Yb) can be potentiality used for betterment of photovoltaic (PV) technology. This result further indicates its potential application as a luminescence converter layer for enhancing solar cells performance.

Enhanced multiferroic properties in scandium doped Bi2Fe4O9

International Nuclear Information System (INIS)

Dutta, Dimple P.; Tyagi, A. K.

2013-01-01

Undoped and Sc 3+ doped Bi 2 Fe 4 O 9 nanoparticles have been synthesized using sonochemical method. The phase purity of the samples was checked using powder X-rau diffraction technique. EDS analysis was done to confirm the extent of Sc 3+ doping in the samples. The size and morphology of the nanoparticles have been analyzed using transmission electron microscopy (TEM). The Bi 2 Fe 4 O 9 nanoparticles show a weak ferromagnetic behavior at room temperature, which is quite different from the linear M–H relationship reported for bulk Bi 2 Fe 4 O 9 . This is mainly attributed to the uncompensated moments at the disordered particle surface resulting from the reduced coordination of the surface spins, arising due to lattice strain or oxygen deficiency. Addition of Sc 3+ dopant in varying concentrations in these Bi 2 Fe 4 O 9 nanoparticles, improves their magnetic as well as ferroelectric properties. The leakage current is considerably reduced and electric polarization increases significantly in case of Bi 2 Fe 4(1-x) Sc x O 9 (x = 0.1) nanoparticles. Hence it can be inferred that Sc 3+ doped Bi 2 Fe 4 O 9 nanoparticles shows promise as good multiferroic materials.

Enrichment of Sc{sub 2}O{sub 3} and TiO{sub 2} from bauxite ore residues

Energy Technology Data Exchange (ETDEWEB)

Deng, Bona; Li, Guanghui, E-mail: liguangh@csu.edu.cn; Luo, Jun; Ye, Qing; Liu, Mingxia; Peng, Zhiwei; Jiang, Tao

2017-06-05

Highlights: • Sc{sub 2}O{sub 3} and TiO{sub 2} from bauxite ore residue were successfully enriched. • H{sub 3}PO{sub 4} and NaOH were efficient for enriching Sc{sub 2}O{sub 3} and TiO{sub 2} by removing SiO{sub 2}, Al{sub 2}O{sub 3}, and partial Fe{sub 2}O{sub 3} and CaO. • Enriching mechanism of Sc{sub 2}O{sub 3} and TiO{sub 2} was explicitly explained. - Abstract: As a major byproduct generated in the alumina industry, bauxite ore residue is an important reserve of scandium and titanium. In this study, the feasibility and mechanism of enriching Sc{sub 2}O{sub 3} and TiO{sub 2} from a non-magnetic material, which was obtained from carbothermal reductive roasting and magnetic separation of bauxite ore residue, were investigated based on a two-step (acidic and alkali) leaching process. It was revealed that approximately 78% SiO{sub 2} and 30–40% of CaO, FeO and Al{sub 2}O{sub 3} were removed from a non-magnetic material with 0.0134 wt.% Sc{sub 2}O{sub 3} and 7.64 wt.% TiO{sub 2} by phosphoric acidic leaching, while about 95% Al{sub 2}O{sub 3} and P{sub 2}O{sub 5} were further leached by subsequent sodium hydroxide leaching of the upper-stream leach residue. A Sc{sub 2}O{sub 3}-, TiO{sub 2}- rich material containing 0.044 wt.% Sc{sub 2}O{sub 3} and 25.5 wt.% TiO{sub 2} was obtained, the recovery and the enrichment factor of Sc{sub 2}O{sub 3} and TiO{sub 2} were about 85% and 5, respectively. The enrichment of Sc{sub 2}O{sub 3} was attributed to higher pH (>3.3) of phosphoric acid solution than its dissolution pH{sup 0}, and the enrichment of TiO{sub 2} was mainly associated with the insoluble perovskite (CaTiO{sub 3}) in the acidic solution at ambient temperature. As Sc{sub 2}O{sub 3} and TiO{sub 2} cannot be dissolved in the alkali solution, they were further enriched in the leach residue.

Amorphous and crystalline In{sub 2}O{sub 3}-based transparent conducting films for photovoltaics

Energy Technology Data Exchange (ETDEWEB)

Koida, Takashi [Research Center for Photovoltaics, National Institute of Advanced Industrial Science and Technology, Tsukuba (Japan)

2017-02-15

We reported solar cells with reduced electrical and optical losses using hydrogen-doped In{sub 2}O{sub 3} (In{sub 2}O{sub 3}:H) transparent conducting layers with low sheet resistance and high transparence characteristics. The transparent conducting oxide (TCO) films were prepared by solid-phase crystallization of amorphous (a-) In{sub 2}O{sub 3}:H films grown by magnetron sputtering. The polycrystalline (poly-) In{sub 2}O{sub 3}:H films exhibited electron mobilities (over 100 cm{sup 2}V{sup -1} s{sup -1}) 2 and 3 times greater than those of conventional TCO films. This paper describes (i) the current status of the electrical properties of In{sub 2}O{sub 3}-based TCO; (ii) the structural and optoelectrical properties of the a-In{sub 2}O{sub 3}:H and poly-In{sub 2}O{sub 3}:H films, focusing on the inhomogeneity and stability characteristics of the films; and (iii) the electrical properties of bilayer TCO. The potential of these high mobility TCO films for solar cells was also described. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Photoelectrochemical Characterization of Sprayed α-Fe2O3 Thin Films: Influence of Si Doping and SnO2 Interfacial Layer

Directory of Open Access Journals (Sweden)

Yongqi Liang

2008-01-01

Full Text Available α-Fe2O3 thin film photoanodes for solar water splitting were prepared by spray pyrolysis of Fe(AcAc3. The donor density in the Fe2O3 films could be tuned between 1017–1020 cm-3 by doping with silicon. By depositing a 5 nm SnO2 interfacial layer between the Fe2O3 films and the transparent conducting substrates, both the reproducibility and the photocurrent can be enhanced. The effects of Si doping and the presence of the SnO2 interfacial layer were systematically studied. The highest photoresponse is obtained for Fe2O3 doped with 0.2% Si, resulting in a photocurrent of 0.37 mA/cm2 at 1.23 VRHE in a 1.0 M KOH solution under 80 mW/cm2 AM1.5 illumination.

Epitaxial growth and magnetic properties of ultraviolet transparent Ga2O3/(Ga1−xFex)2O3 multilayer thin films

Science.gov (United States)

Guo, Daoyou; An, Yuehua; Cui, Wei; Zhi, Yusong; Zhao, Xiaolong; Lei, Ming; Li, Linghong; Li, Peigang; Wu, Zhenping; Tang, Weihua

2016-01-01

Multilayer thin films based on the ferromagnetic and ultraviolet transparent semiconductors may be interesting because their magnetic/electronic/photonic properties can be manipulated by the high energy photons. Herein, the Ga2O3/(Ga1−xFex)2O3 multilayer epitaxial thin films were obtained by alternating depositing of wide band gap Ga2O3 layer and Fe ultrathin layer due to inter diffusion between two layers at high temperature using the laser molecular beam epitaxy technique. The multilayer films exhibits a preferred growth orientation of crystal plane, and the crystal lattice expands as Fe replaces Ga site. Fe ions with a mixed valence of Fe2+ and Fe3+ are stratified distributed in the film and exhibit obvious agglomerated areas. The multilayer films only show a sharp absorption edge at about 250 nm, indicating a high transparency for ultraviolet light. What’s more, the Ga2O3/(Ga1−xFex)2O3 multilayer epitaxial thin films also exhibits room temperature ferromagnetism deriving from the Fe doping Ga2O3. PMID:27121446

Transparent Ga and Zn co-doped In2O3 electrode prepared by co-sputtering of Ga:In2O3 and Zn:In2O3 targets at room temperature