Tuning of "antenna effect" of Eu(III) in ternary systems in aqueous medium through binding with protein.

Science.gov (United States)

Ghorai, Shyamal Kr; Samanta, Swarna Kamal; Mukherjee, Manini; Saha Sardar, Pinki; Ghosh, Sanjib

2013-02-04

A simple ternary system containing a protein [human serum albumin (HSA)/bovine serum albumin (BSA)], tetracycline hydrochloride (TC), and Eu(III) in suitable aqueous buffer medium at physiological pH (= 7.2) has been shown to exhibit highly efficient "antenna effect" compared to the binary complex of TC with Eu(III) (Eu(3)TC). The ternary system containing E. coli alkaline phosphatase (AP), TC, and Eu(III), however, shows a slight enhancement of Eu(III) emission, although the binding constant of AP with TC is 2 orders of magnitude greater than with BSA/HSA. The enhanced emission of bound TC in the binary systems containing proteins and TC gets quenched in the ternary systems containing HSA/BSA, showing the efficient energy transfer (ET) from TC to Eu(III). Steady state and time-resolved emission studies of each component in all the ternary systems in H(2)O and in D(2)O medium reveal that Eu(III) is very well protected from the O-H oscillator in the ternary system containing HSA/BSA compared to that containing AP. The docking studies locating the binding site of TC in the proteins suggest that TC binds near the surface of AP. In the case of HSA/BSA, TC resides in the interior of the protein resulting in a large shielding effect of Eu(III). The rotational correlation time (θ(c)) determined from the anisotropy decay of bound TC in the complexes and the accessible surface area (ASA) of the ligand in the complexes obtained from the docking studies also support the contention that Eu(3)TC is more exposed to solvent in the case of the ternary system consisting of AP, TC, and Eu(III). The calculated radiative lifetime and the sensitization efficiency ratio of Eu(III) in all the systems clearly demonstrate the protein mediated tuning of "antenna effect" in Eu(III).

Controlling the emission wavelength in group III-V semiconductor laser diodes

KAUST Repository

Ooi, Boon S.

2016-12-29

Methods are provided for modifying the emission wavelength of a semiconductor quantum well laser diode, e.g. by blue shifting the emission wavelength. The methods can be applied to a variety of semiconductor quantum well laser diodes, e.g. group III-V semiconductor quantum wells. The group III-V semiconductor can include AlSb, AlAs, Aln, AlP, BN, GaSb, GaAs, GaN, GaP, InSb, InAs, InN, and InP, and group III-V ternary semiconductors alloys such as AlxGai.xAs. The methods can results in a blue shifting of about 20 meV to 350 meV, which can be used for example to make group III-V semiconductor quantum well laser diodes with an emission that is orange or yellow. Methods of making semiconductor quantum well laser diodes and semiconductor quantum well laser diodes made therefrom are also provided.

Ternary Blend Composed of Two Organic Donors and One Acceptor for Active Layer of High-Performance Organic Solar Cells.

Science.gov (United States)

Lee, Jong Won; Choi, Yoon Suk; Ahn, Hyungju; Jo, Won Ho

2016-05-04

Ternary blends composed of two donor absorbers with complementary absorptions provide an opportunity to enhance the short-circuit current and thus the power conversion efficiency (PCE) of organic solar cells. In addition to complementary absorption of two donors, ternary blends may exhibit favorable morphology for high-performance solar cells when one chooses properly the donor pair. For this purpose, we develop a ternary blend with two donors (diketopyrrolopyrrole-based polymer (PTDPP2T) and small molecule ((TDPP)2Ph)) and one acceptor (PC71BM). The solar cell made of a ternary blend with 10 wt % (TDPP)2Ph exhibits higher PCE of 7.49% as compared with the solar cells with binary blends, PTDPP2T:PC71BM (6.58%) and (TDPP)2Ph:PC71BM (3.21%). The higher PCE of the ternary blend solar cell is attributed mainly to complementary absorption of two donors. However, a further increase in (TDPP)2Ph content in the ternary blend (>10 wt %) decreases the PCE. The ternary blend with 10 wt % (TDPP)2Ph exhibits well-developed morphology with narrow-sized fibrils while the blend with 15 wt % (TDPP)2Ph shows phase separation with large-sized domains, demonstrating that the phase morphology and compatibility of ternary blend are important factors to achieve a high-performance solar cell made of ternary blends.

Effect of III-nitride polarization on V{sub OC} in p-i-n and MQW solar cells

Energy Technology Data Exchange (ETDEWEB)

Namkoong, Gon; Boland, Patrick; Foe, Kurniawan; Latimer, Kevin [Department of Electrical and Computer Engineering, Old Dominion University, Applied Research Center, 12050 Jefferson Avenue, Newport News, VA 23606 (United States); Bae, Si-Young; Shim, Jae-Phil; Lee, Dong-Seon [School of Information and Communications, Gwangju Institute of Science and Technology, 261 Cheomdan-gwagiro (Oryong-dong), Buk-gu, Gwangju 500-712 (Korea, Republic of); Jeon, Seong-Ran [Korea Photonics Technology Institute, 971-35, Wolchul-dong, Buk-gu, Gwangju, 500-779 (Korea, Republic of); Doolittle, W. Alan [School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (United States)

2011-02-15

We performed detailed studies of the effect of polarization on III-nitride solar cells. Spontaneous and piezoelectric polarizations were assessed to determine their impacts upon the open circuit voltages (V{sub OC}) in p-i(InGaN)-n and multi-quantum well (MQW) solar cells. We found that the spontaneous polarization in Ga-polar p-i-n solar cells strongly modifies energy band structures and corresponding electric fields in a way that degrades V{sub OC} compared to non-polar p-i-n structures. In contrast, we found that piezoelectric polarization in Ga-polar MQW structures does not have a large influence on V{sub OC} compared to non-polar MQW structures. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Solar neutrino measurements with Super-Kamiokande III

International Nuclear Information System (INIS)

Ikeda, Motoyasu

2008-01-01

The third phase of Super-Kamiokande experiment (SK-III) has been running since 12th July, 2006. The SK-III detector is achieved 40% photo-cathode coverage with 11,129 20-inch PMTs. One of the physics goals in SK-III is observing the transition of solar neutrino oscillations between vacuum and matter oscillation around 4MeV. From 24th January, 2007 to 2nd March, 2008, we obtained data of live-time 288.9 days with energy threshold 6.5MeV (Full Final sample: FF sample). For data with a lower energy threshold 5.0MeV, we needed remove high radon contaminated period from the FF sample, then we obtained another data sample (Radon reduced sample: RR sample) with live-time 191.7 days. The current measurements show that SK-III has already achieved a similar signal to noise ratio as SK-I for energy range from 5.0 to 20.0MeV, and the solar angle distribution of FF sample shows that the solar neutrino event rate also looks consistent with SK-I for energy range from 6.5 to 20.0MeV. As for the RR sample, although the vertex distribution of low energy events is not uniform in the detector and there are more BG events in the edge of fiducial volume, it is clear that SK-III BG level is smaller than that of SK-I in the central region of the detector. Finally, the future plan for lowering the energy threshold shows a 2a discovery potential of the energy spectrum upturn with 3 years of observation after both software and hardware improvements.

Progress in the development of metamorphic multi-junction III-V space solar cells

Energy Technology Data Exchange (ETDEWEB)

Sinharoy, S.; Patton, M.O.; Valko, T.M.; Weizer, V.G. [Essential Research Inc., Cleveland, OH (United States)

2002-07-01

Theoretical calculations have shown that highest-efficiency III-V multi-junction solar cells require alloy structures that cannot be grown on a lattice-matched substrate. Ever since the first demonstration of high efficiency metamorphic single-junction 1.1 and 1.2 eV InGaAs solar cells, interest has grown in the development of multi-junction cells of this type, using graded buffer layer technology. Essential Research Incorporated (ERI) is currently developing a dual-junction 1.6 eV InGaP/1.1 eV InGaAs tandem cell (projected practical air-mass zero (AMO), one-sun efficiency of 27%, and 100-sun efficiency of 31.1%) under a Ballistic Missile Defense Command (BMDO) SBIR Phase II program. A second ongoing research effort involves the development of a 2.1 eV A1GaInP/1.6 eV InGaAsP/1.2 eV InGaAs triple-junction concentrator tandem cell (projected practical AMO efficiency 36.5% under 100 suns) under a SBIR Phase II program funded by the Air Force. We are in the process of optimizing the dual-junction cell performance. For the triple-junction cell, we have developed the bottom and the middle cell, and are in the process of developing the layer structures needed for the top cell. A progress report is presented in this paper. (author)

Optimization of the silicon subcell for III-V on silicon multijunction solar cells: Key differences with conventional silicon technology

Science.gov (United States)

García-Tabarés, Elisa; Martín, Diego; García, Iván; Lelièvre, Jean François; Rey-Stolle, Ignacio

2012-10-01

Dual-junction solar cells formed by a GaAsP or GaInP top cell and a silicon (Si) bottom cell seem to be attractive candidates to materialize the long sought-for integration of III-V materials on Si for photovoltaic (PV) applications. Such integration would offer a cost breakthrough for PV technology, unifying the low cost of Si and the efficiency potential of III-V multijunction solar cells. The optimization of the Si solar cells properties in flat-plate PV technology is well-known; nevertheless, it has been proven that the behavior of Si substrates is different when processed in an MOVPE reactor In this study, we analyze several factors influencing the bottom subcell performance, namely, 1) the emitter formation as a result of phosphorus diffusion; 2) the passivation quality provided by the GaP nucleation layer; and 3) the process impact on the bottom subcell PV properties.

High-performance ternary blend polymer solar cells involving both energy transfer and hole relay processes.

Science.gov (United States)

Lu, Luyao; Chen, Wei; Xu, Tao; Yu, Luping

2015-06-04

The integration of multiple materials with complementary absorptions into a single junction device is regarded as an efficient way to enhance the power conversion efficiency (PCE) of organic solar cells (OSCs). However, because of increased complexity with one more component, only limited high-performance ternary systems have been demonstrated previously. Here we report an efficient ternary blend OSC with a PCE of 9.2%. We show that the third component can reduce surface trap densities in the ternary blend. Detailed studies unravel that the improved performance results from synergistic effects of enlarged open circuit voltage, suppressed trap-assisted recombination, enhanced light absorption, increased hole extraction, efficient energy transfer and better morphology. The working mechanism and high device performance demonstrate new insights and design guidelines for high-performance ternary blend solar cells and suggest that ternary structure is a promising platform to boost the efficiency of OSCs.

Growth and characterization of III-N ternary thin films by plasma assisted atomic layer epitaxy at low temperatures

Energy Technology Data Exchange (ETDEWEB)

Nepal, Neeraj; Anderson, Virginia R.; Hite, Jennifer K.; Eddy, Charles R.

2015-08-31

We report the growth and characterization of III-nitride ternary thin films (Al{sub x}Ga{sub 1−x}N, In{sub x}Al{sub 1−x}N and In{sub x}Ga{sub 1−x}N) at ≤ 500 °C by plasma assisted atomic layer epitaxy (PA-ALE) over a wide stoichiometric range including the range where phase separation has been an issue for films grown by molecular beam epitaxy and metal organic chemical vapor deposition. The composition of these ternaries was intentionally varied through alterations in the cycle ratios of the III-nitride binary layers (AlN, GaN, and InN). By this digital alloy growth method, we are able to grow III-nitride ternaries by PA-ALE over nearly the entire stoichiometry range including in the spinodal decomposition region (x = 15–85%). These early efforts suggest great promise of PA-ALE at low temperatures for addressing miscibility gap challenges encountered with conventional growth methods and realizing high performance optoelectronic and electronic devices involving ternary/binary heterojunctions, which are not currently possible. - Highlights: • III-N ternaries grown at ≤ 500 °C by plasma assisted atomic layer epitaxy • Growth of InGaN and AlInN in the spinodal decomposition region (15–85%) • Epitaxial, smooth and uniform III-N film growth at low temperatures.

Growth and characterization of III-N ternary thin films by plasma assisted atomic layer epitaxy at low temperatures

International Nuclear Information System (INIS)

Nepal, Neeraj; Anderson, Virginia R.; Hite, Jennifer K.; Eddy, Charles R.

2015-01-01

We report the growth and characterization of III-nitride ternary thin films (Al x Ga 1−x N, In x Al 1−x N and In x Ga 1−x N) at ≤ 500 °C by plasma assisted atomic layer epitaxy (PA-ALE) over a wide stoichiometric range including the range where phase separation has been an issue for films grown by molecular beam epitaxy and metal organic chemical vapor deposition. The composition of these ternaries was intentionally varied through alterations in the cycle ratios of the III-nitride binary layers (AlN, GaN, and InN). By this digital alloy growth method, we are able to grow III-nitride ternaries by PA-ALE over nearly the entire stoichiometry range including in the spinodal decomposition region (x = 15–85%). These early efforts suggest great promise of PA-ALE at low temperatures for addressing miscibility gap challenges encountered with conventional growth methods and realizing high performance optoelectronic and electronic devices involving ternary/binary heterojunctions, which are not currently possible. - Highlights: • III-N ternaries grown at ≤ 500 °C by plasma assisted atomic layer epitaxy • Growth of InGaN and AlInN in the spinodal decomposition region (15–85%) • Epitaxial, smooth and uniform III-N film growth at low temperatures

Solar neutrino oscillation parameters after SNO Phase-III and SAGE Part-III

International Nuclear Information System (INIS)

Yang Ping; Liu Qiuyu

2009-01-01

We analyse the recently published results from solar neutrino experiments SNO Phase-III and SAGE Part-III and show their constraints on solar neutrino oscillation parameters, especially for the mixing angle θ 12 . Through a global analysis using all existing data from SK, SNO, Ga and Cl radiochemical experiments and long base line reactor experiment KamLAND , we obtain the parameters Δm 12 2 =7.684 -0.208 +0.212 x 10 -5 eV 2 , tan 2 θ 12 =0.440 -0.057 +0.059 . We also find that the discrepancy between the KamLAND and solar neutrino results can be reduced by choosing a small non-zero value for the mixing angle θ 13 . (authors)

The role of In in III-nitride ternary semiconductors

CERN Multimedia

Redondo cubero, A

This proposal aims to study the role of In in the outstanding efficiency of luminescent devices based on group III-nitride ternary semiconductors. To study the microscopic environments of In in GaInN and AlInN, Perturbed Angular Correlation (PAC) experiments will be performed using the PAC-probes $^{111m}$Cd($^{111}$Cd), $^{115}$Cd($^{115}$In) and $^{117}$Cd($^{117}$In). Temperature dependent PAC measurements using the $^{111}$In($^{111}$Cd) probe indicated that In in GaN and AlN forms a complex with a defect, possibly a nitrogen vacancy (V$_{N}$), which is stable up to high temperatures and might be involved in the luminescence mechanisms. Analysing these results two questions arose: \\\\ \\\\1. Does the fact that the actual measurement is performed with the daughter nucleus $^{111}$Cd (being an acceptor) influence the probe-defect interaction? This question can be answered by performing measurements with the complementary probe $^{117}$Cd($^{117}$In). \\\\ \\\\ 2. What is the significance of $\\textit{a...

Binary and ternary chelates of Sc(III), Y(III) and La(III) with ethylenediamine tetraacetic acid as primary ligand and substituted salicylic acids as secondary ligands

Energy Technology Data Exchange (ETDEWEB)

Pandey, A K; Chandra, M; Agarwala, B V; Dey, A K [Allahabad Univ. (India). Chemical Labs.

1980-02-01

Study of ternary complex formation of several tripositive metal ions viz. Sc(III), Y(III) and La(III) with ethylenediamine tetraacetic acid (EDTA) as a primary ligand and 5-chlorosalicylic acid (CSA) or 3,5-dibromosalicylic acid (DBSA) as secondary ligands by pH-metric titration technique is reported. The stability order of metal chelates with respect to ligands is observed to be DBSA>CSA and with respect to metal ions Sc(III)>Y(III)>La(III).

Photophysical study of blue-light excitable ternary Eu(III) complexes and their encapsulation into polystyrene nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Räsänen, Markus, E-mail: mpvras@utu.fi [Department of Chemistry, University of Turku, FIN-20014 Turku (Finland); Takalo, Harri [DHR Finland Oy, Innotrac Diagnostics, Biolinja 12, FIN-20750 Turku (Finland); Soukka, Tero [Department of Biochemistry/Biotechnology, University of Turku, FIN-20014 Turku (Finland); Haapakka, Keijo; Kankare, Jouko [Department of Chemistry, University of Turku, FIN-20014 Turku (Finland)

2015-04-15

In this work, 14 ternary Eu(III) complexes were studied by means of spectroscopy. The studied Eu(III) complexes consisted of Lewis bases (4′-(4-diethylaminophenyl)-2,2′:6′,2″-terpyridine (L{sup 8}) or 1,10-phenanthroline (L{sup 9})) and differently substituted β-diketones. The ternary complexes with L{sup 8} show the excitation peak at 405 nm and the quantum yield even 76%. The brightest ternary complex at the 405 nm excitation was Eu(L{sup 3}){sub 3}L{sup 8} while Eu(L{sup 7}){sub 3}L{sup 8} (HL{sup 3}=4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione, HL{sup 7}=1-(9-ethyl-9H-carbazol-3-yl)-4,4,5,5,5-pentafluoro-1,3-pentanedione) was found to be the brightest at the ligand-centred excitation maximum. The ternary complexes were studied mainly in toluene as the model environment for the polystyrene nanoparticle cavities. The complexes were successfully loaded into the polystyrene nanoparticles enabling their bioanalytical application in aqueous environment. The encapsulation of the complexes preserved, or even enhanced, their good photophysical features. - Highlights: • Ternary Eu{sup 3+} complexes with some β-diketone and substituted terpyridine were studied. • Ternary complexes with substituted terpyridine showed blue-light excitability. • Ternary complexes were successfully loaded into the polystyrene nanoparticles. • Encapsulation of the complexes preserved their good photophysical features.

Photon confinement in high-efficiency, thin-film III-V solar cells obtained by epitaxial lift-off

International Nuclear Information System (INIS)

Schermer, J.J.; Bauhuis, G.J.; Mulder, P.; Haverkamp, E.J.; Deelen, J. van; Niftrik, A.T.J. van; Larsen, P.K.

2006-01-01

Using the epitaxial lift-off (ELO) technique, a III-V device structure can be separated from its GaAs substrate by selective wet etching of a thin release layer. The thin-film structures obtained by the ELO process can be cemented or van der Waals bonded on arbitrary smooth surface carriers for further processing. It is shown that the ELO method, initially able to separate millimetre-sized GaAs layers with a lateral etch rate of about 1 mm/h, has been developed to a process capable to free the entire 2-in. epitaxial structures from their substrates with etch rates up to 30 mm/h. With these characteristics the method has a large potential for the production of high efficiency thin-film solar cells. By choosing the right deposition and ELO strategy, the thin-film III-V cells can be adequately processed on both sides allowing for an entire range of new cell structures. In the present work, the performance of semi-transparent bifacial solar cells, produced by the deposition of metal grid contacts on both sides, was evaluated. Reflection of light at the rear side of the bifacial GaAs solar cells was found to result in an enhanced collection probability of the photon-induced carriers compared to that of regular III-V cells on a GaAs substrate. To enhance this effect, thin-film GaAs cells with gold mirror back contacts were prepared. Even in their present premature stage of development, these single-junction thin-film cells reached a record efficiency of 24.5% which is already very close to the 24.9% efficiency that was obtained with a regular GaAs cell on a GaAs substrate. From this it could be concluded that, as a result of the photon confinement, ELO cells require a significantly thinner base layer than regular GaAs cells while at the same time they have the potential to reach a higher efficiency

Experimental investigation of phase equilibria in the Ni-Nb-V ternary system

Energy Technology Data Exchange (ETDEWEB)

Liu, Xingjun; Yang, Shuiyuan; Wang, Cuiping [Xiamen Univ. (China). Dept. of Materials Science and Engineering; Xiamen Univ. (China). Fujian Provincial Key Lab. of Materials Genome; Zhang, Xianjie; Jiang, Hengxing; Shi, Zhan [Xiamen Univ. (China). Dept. of Materials Science and Engineering

2017-09-15

The phase equilibria of the Ni-Nb-V ternary system at 1000 C and 1200 C were established using electron probe microanalysis, X-ray diffraction and differential scanning calorimetry. The results of the investigation revealed that: (1) The Nb solubility in (Ni) and σ{sup '} phases was less than 10 at.%; (2) A ternary compound τ (NiNbV) was confirmed, in which V had a large solubility; (3) A new liquid region was evident at 1200 C, but was absent at 1000 C; (4) The lattice constants of Ni{sub 3}Nb and Ni{sub 6}Nb{sub 7} phase decreased with increase in V content in the Ni{sub 3}Nb and Ni{sub 6}Nb{sub 7}. The phase equilibria of the Ni-Nb-V ternary system will contribute to its thermodynamic assessment.

Ternary Organic Solar Cells with Coumarin7 as the Donor Exhibiting Greater Than 10% Power Conversion Efficiency and a High Fill Factor of 75.

Science.gov (United States)

Chen, Xin-Wei; Tao, Si-Lu; Fan, Cong; Chen, Dong-Cheng; Zhou, Ling; Lin, Hui; Zheng, Cai-Jun; Su, Shi-Jian

2017-09-06

Ternary bulk heterojunction (BHJ) is a brilliant photovoltaic technology for improving the performance of organic solar cells (OSCs), because the light absorption range can be significantly extended by using multiple donors or acceptor materials. In this paper, coumarin7 (C7), a small organic molecule typical led used in organic light-emitting diodes, was initially exploited as second electron-donor component in ternary bulk heterojunction OSCs along with conventional blend system spolythieno[3,4-b]-thiophene/benzodithiophene(PTB7) and [6,6]-phenyl-C71 -butyric acid methyl(PC 71 BM). A champion PCE value of 10.28% was realized in the ternary OSCs when incorporated with 10 wt % C7 doping ratio in the donors, corresponding to about 35% enhancement compared with the PTB7:PC 71 BM-based OSCs, a high fill factor (FF) of 75.03%, a short-circuit currentdensity (J sc ) of 18.72 mA cm -2 and an open-circuit voltage (V oc ) of 0.73 V. The enhanced performance of the ternary OSCs can be attributed to the simultaneous improvement of the FF and the J sc . In addition to extended light absorption, a perfect nanofiber filament active layer morphology is obtained due to the good compatibility between C7 and PTB7, which facilitates the balance of charge transportation and the suppression of charge recombination. This investigation suggests that coumarin derivatives, which have completely different structure with polymer donors, can also be used to fabricate ternary solar cells and have the potential applications to obtain amazing performance after further device engineering and optimization.

Ternary solution-processed organic solar cells incorporating 2D materials

Science.gov (United States)

Stylianakis, Minas M.; Konios, Dimitrios; Petridis, Constantinos; Kakavelakis, George; Stratakis, Emmanuel; Kymakis, Emmanuel

2017-12-01

Recently, the study of ternary organic solar cells (OSCs) has attracted the efforts of the scientific community, leading to significantly higher performance due to the enhanced harvesting of incoming irradiation. Here, for the first time, and in order to promote this OSC architecture, we review the progress implemented by the application of two-dimensional (2D) materials in the field of blend bulk heterojunction ternary OSCs. Power conversion efficiency (PCE) improvements of the order of 40% compared to the reference binary devices, and PCEs in excess of 8% have been reported by incorporating graphene-based or other 2D materials as a third element inside the active layer. These OSCs combine the synergetic advantages of ternary devices and the superb properties of the 2D material family. In conclusion, the incorporation of the unique properties of graphene and other 2D materials inside the active layer opens up a very promising pathway in the design and construction of high-performance, simply fabricated and low- cost photovoltaic devices.

Development of III-V/Si Multijunction Space Photovoltaics

Data.gov (United States)

National Aeronautics and Space Administration — High substrate costs, as well as weight, typically play a major role in the high costs of multijunction space solar cell production and deployment. III-V/Si...

Simultaneous improvement in short circuit current, open circuit voltage, and fill factor of polymer solar cells through ternary strategy.

Science.gov (United States)

An, Qiaoshi; Zhang, Fujun; Li, Lingliang; Wang, Jian; Sun, Qianqian; Zhang, Jian; Tang, Weihua; Deng, Zhenbo

2015-02-18

We present a smart strategy to simultaneously increase the short circuit current (Jsc), the open circuit voltage (Voc), and the fill factor (FF) of polymer solar cells (PSCs). A two-dimensional conjugated small molecule photovoltaic material (SMPV1), as the second electron donor, was doped into the blend system of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C71-butyric acid methyl (PC71BM) to form ternary PSCs. The ternary PSCs with 5 wt % SMPV1 doping ratio in donors achieve 4.06% champion power conversion efficiency (PCE), corresponding to about 21.2% enhancement compared with the 3.35% PCE of P3HT:PC71BM-based PSCs. The underlying mechanism on performance improvement of ternary PSCs can be summarized as (i) harvesting more photons in the longer wavelength region to increase Jsc; (ii) obtaining the lower mixed highest occupied molecular orbital (HOMO) energy level by incorporating SMPV1 to increase Voc; (iii) forming the better charge carrier transport channels through the cascade energy level structure and optimizing phase separation of donor/acceptor materials to increase Jsc and FF.

Relationship between type III-V radio and hard X-ray bursts

International Nuclear Information System (INIS)

Stewart, R.T.

1978-01-01

Type III-V radio bursts are found to be closely associated with impulsive hard X-ray bursts. Probably 0.1% to 1% of the fast electrons in the X-ray source region escape to heights >0.1 solar radii in the corona and excite the type III-V burst. (Auth.)

III-V/Si wafer bonding using transparent, conductive oxide interlayers

Energy Technology Data Exchange (ETDEWEB)

Tamboli, Adele C., E-mail: Adele.Tamboli@nrel.gov; Hest, Maikel F. A. M. van; Steiner, Myles A.; Essig, Stephanie; Norman, Andrew G.; Bosco, Nick; Stradins, Paul [National Center for Photovoltaics, National Renewable Energy Laboratory, 15013 Denver West Pkwy, Golden, Colorado 80401 (United States); Perl, Emmett E. [Department of Electrical and Computer Engineering, University of California, Santa Barbara, California 93106-9560 (United States)

2015-06-29

We present a method for low temperature plasma-activated direct wafer bonding of III-V materials to Si using a transparent, conductive indium zinc oxide interlayer. The transparent, conductive oxide (TCO) layer provides excellent optical transmission as well as electrical conduction, suggesting suitability for Si/III-V hybrid devices including Si-based tandem solar cells. For bonding temperatures ranging from 100 °C to 350 °C, Ohmic behavior is observed in the sample stacks, with specific contact resistivity below 1 Ω cm{sup 2} for samples bonded at 200 °C. Optical absorption measurements show minimal parasitic light absorption, which is limited by the III-V interlayers necessary for Ohmic contact formation to TCOs. These results are promising for Ga{sub 0.5}In{sub 0.5}P/Si tandem solar cells operating at 1 sun or low concentration conditions.

Single-layer group IV-V and group V-IV-III-VI semiconductors: Structural stability, electronic structures, optical properties, and photocatalysis

Science.gov (United States)

Lin, Jia-He; Zhang, Hong; Cheng, Xin-Lu; Miyamoto, Yoshiyuki

2017-07-01

Recently, single-layer group III monochalcogenides have attracted both theoretical and experimental interest at their potential applications in photonic devices, electronic devices, and solar energy conversion. Excited by this, we theoretically design two kinds of highly stable single-layer group IV-V (IV =Si ,Ge , and Sn; V =N and P) and group V-IV-III-VI (IV =Si ,Ge , and Sn; V =N and P; III =Al ,Ga , and In; VI =O and S) compounds with the same structures with single-layer group III monochalcogenides via first-principles simulations. By using accurate hybrid functional and quasiparticle methods, we show the single-layer group IV-V and group V-IV-III-VI are indirect bandgap semiconductors with their bandgaps and band edge positions conforming to the criteria of photocatalysts for water splitting. By applying a biaxial strain on single-layer group IV-V, single-layer group IV nitrides show a potential on mechanical sensors due to their bandgaps showing an almost linear response for strain. Furthermore, our calculations show that both single-layer group IV-V and group V-IV-III-VI have absorption from the visible light region to far-ultraviolet region, especially for single-layer SiN-AlO and SnN-InO, which have strong absorption in the visible light region, resulting in excellent potential for solar energy conversion and visible light photocatalytic water splitting. Our research provides valuable insight for finding more potential functional two-dimensional semiconductors applied in optoelectronics, solar energy conversion, and photocatalytic water splitting.

Final Report: Vapor Transport Deposition for Thin Film III-V Photovoltaics

Energy Technology Data Exchange (ETDEWEB)

Boettcher, Shannon [Univ. of Oregon, Eugene, OR (United States); Greenaway, Ann [Univ. of Oregon, Eugene, OR (United States); Boucher, Jason [Univ. of Oregon, Eugene, OR (United States); Aloni, Shaul [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2016-02-10

ternary GaAsxP_1-x and In_0.5Ga_0.5P alloys, with composition set by the ratio of GaAs/GaP or InP/GaP mixed as the source powder. GaAs_0.3P_0.7 has the appropriate bandgap to serve as a top cell on Si and In_0.5Ga_0.5P is near the composition used as a surface passivation layer on GaAs pn junction photovoltaics. In the final task we demonstrated III-V selective area epitaxy using CSVT as a first step toward the growth of III-V micro- or nanostructures for an integrated tandem solar cell on Si. We also found that direct epitaxial growth on Si appears to be impossible in the current H₂O-CSVT reactor design, likely due to the formation of SiO_x. This work sets the stage for targeted development of an improved CSVT process and for the scale up of the proof-of-concept work from a research to manufacturing-relevant platform. Replacing H₂O as a transport agent with HCl would provide the ability to deposit directly on Si by avoiding oxide formation and to allow for the deposition of Al-containing alloys that would otherwise oxidize. Improved engineering design and implementation of an in-line multi-station CSVT would allow for direct deposition of device structures in a single system.

Study of a ternary blend system for bulk heterojunction thin film solar cells

Science.gov (United States)

Ahmad, Zubair; Touati, Farid; Shakoor, R. A.; Al-Thani, N. J.

2016-08-01

In this research, we report a bulk heterojunction (BHJ) solar cell consisting of a ternary blend system. Poly(3-hexylthiophene) P3HT is used as a donor and [6,6]-phenyl C61-butyric acid methylester (PCBM) plays the role of acceptor whereas vanadyl 2,9,16,23-tetraphenoxy-29H, 31H-phthalocyanine (VOPcPhO) is selected as an ambipolar transport material. The materials are selected and assembled in such a fashion that the generated charge carriers could efficiently be transported rightwards within the blend. The organic BHJ solar cells consist of ITO/PEDOT:PSS/ternary BHJ blend/Al structure. The power conversion efficiencies of the ITO/ PEDOT:PSS/P3HT:PCBM/Al and ITO/PEDOT:PSS/ P3HT:PCBM:VOPcPhO/Al solar cells are found to be 2.3% and 3.4%, respectively. This publication was made possible by PDRA (Grant No. PDRA1-0117-14109) from the Qatar National Research Fund (a member of Qatar Foundation). The findings achieved herein are solely the responsibility of the authors.

Superconductivity and specific heat measurements in V--Nb--Ta ternary alloys

International Nuclear Information System (INIS)

Wang, R.Y.P.

1977-01-01

The correlation between the superconducting transition temperature T/sub c/ with electronic specific heat coefficient γ and Debye temperature theta/sub D/ in some isoelectronic ternary V--Nb--Ta alloys is investigated. It has been known that the variation of theta/sub D/ with concentration in both V--Nb and V--Ta systems is clearly of the same curvature as that of T/sub c/ and γ. In Ta--Nb alloys, however, over most of the concentration range theta/sub D/ seems to have a slight negative curvature while T/sub c/ and γ curve upwards. (But beyond approx. 80 at. % Nb theta/sub D/ rises rapidly to the pure Nb value.) By choosing alloys along a line connecting Ta and V 25 --Nb 75 which is close to the Nb--Ta side of the Gibb's triangle the extent to which the Nb--Ta type of behavior persists in this ternary system can be estimated. A model proposed by Miedema that takes into account the variation of properties caused by possible charge transfer among constituent atoms in an alloy has been found to apply almost quantitatively for nearly all binary alloy systems whose experimental data are available, including those for which Hopfield's method fails. A previous test of the extension of Miedema's empirical model into ternary alloys shows qualitatively correct behavior for intra-row Zr/sub x/Nb/sub 1-2x/Mo/sub x/ alloys. The good agreement between the predicted values of γ and T/sub c/ and the experimental values in the inter-row ternary V--Nb--Ta system studied here gives another and better test of the application of Miedema's model

Scattering amplitudes and static atomic correction factors for the composition-sensitive 002 reflection in sphalerite ternary III-V and II-VI semiconductors.

Science.gov (United States)

Schowalter, M; Müller, K; Rosenauer, A

2012-01-01

Modified atomic scattering amplitudes (MASAs), taking into account the redistribution of charge due to bonds, and the respective correction factors considering the effect of static atomic displacements were computed for the chemically sensitive 002 reflection for ternary III-V and II-VI semiconductors. MASAs were derived from computations within the density functional theory formalism. Binary eight-atom unit cells were strained according to each strain state s (thin, intermediate, thick and fully relaxed electron microscopic specimen) and each concentration (x = 0, …, 1 in 0.01 steps), where the lattice parameters for composition x in strain state s were calculated using continuum elasticity theory. The concentration dependence was derived by computing MASAs for each of these binary cells. Correction factors for static atomic displacements were computed from relaxed atom positions by generating 50 × 50 × 50 supercells using the lattice parameter of the eight-atom unit cells. Atoms were randomly distributed according to the required composition. Polynomials were fitted to the composition dependence of the MASAs and the correction factors for the different strain states. Fit parameters are given in the paper.

A Review of Ultrahigh Efficiency III-V Semiconductor Compound Solar Cells: Multijunction Tandem, Lower Dimensional, Photonic Up/Down Conversion and Plasmonic Nanometallic Structures

Directory of Open Access Journals (Sweden)

Katsuaki Tanabe

2009-07-01

Full Text Available Solar cells are a promising renewable, carbon-free electric energy resource to address the fossil fuel shortage and global warming. Energy conversion efficiencies around 40% have been recently achieved in laboratories using III-V semiconductor compounds as photovoltaic materials. This article reviews the efforts and accomplishments made for higher efficiency III-V semiconductor compound solar cells, specifically with multijunction tandem, lower-dimensional, photonic up/down conversion, and plasmonic metallic structures. Technological strategies for further performance improvement from the most efficient (AlInGaP/(InGaAs/Ge triple-junction cells including the search for 1.0 eV bandgap semiconductors are discussed. Lower-dimensional systems such as quantum well and dot structures are being intensively studied to realize multiple exciton generation and multiple photon absorption to break the conventional efficiency limit. Implementation of plasmonic metallic nanostructures manipulating photonic energy flow directions to enhance sunlight absorption in thin photovoltaic semiconductor materials is also emerging.

Enhancing Performance of Large-Area Organic Solar Cells with Thick Film via Ternary Strategy.

Science.gov (United States)

Zhang, Jianqi; Zhao, Yifan; Fang, Jin; Yuan, Liu; Xia, Benzheng; Wang, Guodong; Wang, Zaiyu; Zhang, Yajie; Ma, Wei; Yan, Wei; Su, Wenming; Wei, Zhixiang

2017-06-01

Large-scale fabrication of organic solar cells requires an active layer with high thickness tolerability and the use of environment-friendly solvents. Thick films with high-performance can be achieved via a ternary strategy studied herein. The ternary system consists of one polymer donor, one small molecule donor, and one fullerene acceptor. The small molecule enhances the crystallinity and face-on orientation of the active layer, leading to improved thickness tolerability compared with that of a polymer-fullerene binary system. An active layer with 270 nm thickness exhibits an average power conversion efficiency (PCE) of 10.78%, while the PCE is less than 8% with such thick film for binary system. Furthermore, large-area devices are successfully fabricated using polyethylene terephthalate (PET)/Silver gride or indium tin oxide (ITO)-based transparent flexible substrates. The product shows a high PCE of 8.28% with an area of 1.25 cm 2 for a single cell and 5.18% for a 20 cm 2 module. This study demonstrates that ternary organic solar cells exhibit great potential for large-scale fabrication and future applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High-performance ternary blend polymer solar cells involving both energy transfer and hole relay processes

OpenAIRE

Lu, Luyao; Chen, Wei; Xu, Tao; Yu, Luping

2015-01-01

The integration of multiple materials with complementary absorptions into a single junction device is regarded as an efficient way to enhance the power conversion efficiency (PCE) of organic solar cells (OSCs). However, because of increased complexity with one more component, only limited high-performance ternary systems have been demonstrated previously. Here we report an efficient ternary blend OSC with a PCE of 9.2%. We show that the third component can reduce surface trap densities in the...

Preparation and photoluminescence enhancement in terbium(III ternary complexes with β-diketone and monodentate auxiliary ligands

Directory of Open Access Journals (Sweden)

Devender Singh

2016-12-01

Full Text Available A series of new solid ternary complexes of terbium(III ion based on β-diketone ligand acetylacetone (acac and monodentate auxiliary ligands (aqua/urea/triphenylphosphineoxide/pyridine-N-oxide had been prepared. The structural characterizations of synthesized ternary compounds were studied by means of elemental analysis, infrared (IR, and proton nuclear magnetic resonance (NMR spectral techniques. The optical characteristics were investigated with absorption as well as photoluminescence spectroscopy. Thermal behavior of compounds was examined by TGA/DTA analysis and all metal complexes were found to have good thermal stability. The luminescence decay time of complexes were also calculated by monitoring at emission wavelength corresponding to 5D4 → 7F5 transition. A comparative inspection of the luminescent behavior of prepared ternary compounds was performed in order to determine the function of auxiliary ligands in the enhancement of luminescence intensity produced by central terbium(III ion. The color coordinates values suggested that compounds showed bright green emission in visible region in electromagnetic spectrum. Complexes producing green light could play a significant role in the fabrication of efficient light conversion molecular devices for display purposes and lightning systems.

Two Dimensional Effective Electron Mass at the Fermi Level in Quantum Wells of III-V, Ternary and Quaternary Semiconductors.

Science.gov (United States)

Chakrabarti, S; Chatterjee, B; Debbarma, S; Ghatak, K P

2015-09-01

In this paper we study the influence of strong electric field on the two dimensional (2D)effective electron mass (EEM) at the Fermi level in quantum wells of III-V, ternary and quaternary semiconductors within the framework of k x p formalism by formulating a new 2D electron energy spectrum. It appears taking quantum wells of InSb, InAs, Hg(1-x)Cd(x)Te and In(1-x)Ga(x)As(1-y)P(y) lattice matched to InP as examples that the EEM increases with decreasing film thickness, increasing electric field and increases with increasing surface electron concentration exhibiting spikey oscillations because of the crossing over of the Fermi level by the quantized level in quantum wells and the quantized oscillation occurs when the Fermi energy touches the sub-band energy. The electric field makes the mass quantum number dependent and the oscillatory mass introduces quantum number dependent mass anisotropy in addition to energy. The EEM increases with decreasing alloy composition where the variations are totally band structure dependent. Under certain limiting conditions all the results for all the cases get simplified into the well-known parabolic energy bands and thus confirming the compatibility test. The content of this paper finds three applications in the fields of nano-science and technology.

Insight Into the Role of PC71BM on Enhancing the Photovoltaic Performance of Ternary Organic Solar Cells.

Science.gov (United States)

Wang, Bei; Fu, Yingying; Yan, Chi; Zhang, Rui; Yang, Qingqing; Han, Yanchun; Xie, Zhiyuan

2018-01-01

The development of non-fullerene acceptor molecules have remarkably boosted power conversion efficiency (PCE) of polymer solar cells (PSCs) due to the improved spectral coverage and reduced energy loss. An introduction of fullerene molecules into the non-fullerene acceptor-based blend may further improve the photovoltaic performance of the resultant ternary PSCs. However, the underlying mechanism is still debatable. Herein, the ternary PSCs based on PBDB-T:ITIC:PC 71 BM blend were fabricated and its PCE was increased to 10.2% compared to 9.2% for the binary PBDB-T:ITIC devices and 8.1% for the PBDB-T:PC 71 BM PSCs. Systematic investigation was carried out to disclose the effect of PC 71 BM on the blend morphology and charge transport behavior. It is found that the PC 71 BM tends to intermix with the PBDB-T donor compared to the ITIC counterpart. A small amount of PC 71 BM in the ternary blend is helpful for ITIC to aggregate and form efficient electron-transport pathways. Accordingly, the electron mobility is increased and the density of electron traps is decreased in the ternary blend in comparison with the PBDB-T:ITIC blend. Finally, the suppressed bimolecular recombination and enhanced charge collection lead to high PCE for the ternary solar cells.

Ternary Nonfullerene Polymer Solar Cells with 12.16% Efficiency by Introducing One Acceptor with Cascading Energy Level and Complementary Absorption.

Science.gov (United States)

Jiang, Weigang; Yu, Runnan; Liu, Zhiyang; Peng, Ruixiang; Mi, Dongbo; Hong, Ling; Wei, Qiang; Hou, Jianhui; Kuang, Yongbo; Ge, Ziyi

2018-01-01

A novel small-molecule acceptor, (2,2'-((5E,5'E)-5,5'-((5,5'-(4,4,9,9-tetrakis(5-hexylthiophen-2-yl)-4,9-dihydro-s-indaceno[1,2-b:5,6-b']dithiophene-2,7-diyl)bis(4-(2-ethylhexyl)thiophene-5,2-diyl))bis(methanylylidene)) bis(3-hexyl-4-oxothiazolidine-5,2-diylidene))dimalononitrile (ITCN), end-capped with electron-deficient 2-(3-hexyl-4-oxothiazolidin-2-ylidene)malononitrile groups, is designed, synthesized, and used as the third component in fullerene-free ternary polymer solar cells (PSCs). The cascaded energy-level structure enabled by the newly designed acceptor is beneficial to the carrier transport and separation. Meanwhile, the three materials show a complementary absorption in the visible region, resulting in efficient light harvesting. Hence, the PBDB-T:ITCN:IT-M ternary PSCs possess a high short-circuit current density (J sc ) under an optimal weight ratio of donors and acceptors. Moreover, the open-circuit voltage (V oc ) of the ternary PSCs is enhanced with an increase of the third acceptor ITCN content, which is attributed to the higher lowest unoccupied molecular orbital energy level of ITCN than that of IT-M, thus exhibits a higher V oc in PBDB-T:ITCN binary system. Ultimately, the ternary PSCs achieve a power conversion efficiency of 12.16%, which is higher than the PBDB-T:ITM-based PSCs (10.89%) and PBDB-T:ITCN-based ones (2.21%). This work provides an effective strategy to improve the photovoltaic performance of PSCs. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Analytical Electron Diffraction from Iii-V and II-Vi Semiconductors

Science.gov (United States)

Spellward, Paul

Available from UMI in association with The British Library. This thesis describes the development and evaluation of a number of new TEM-based techniques for the measurement of composition in ternary III-V and II-VI semiconductors. New methods of polarity determination in binary and ternary compounds are also presented. The theory of high energy electron diffraction is outlined, with particular emphasis on zone axis diffraction from well-defined strings. An account of TEM microstructural studies of Cd_{rm x}Hg _{rm 1-x}Te and CdTe epitaxial layers, which provided the impetus for developing the diffraction-based analytical techniques, is given. The wide range of TEM-based compositional determination techniques is described. The use of HOLZ deficiency lines to infer composition from a lattice parameter measurement is evaluated. In the case of Cd_{ rm x}Hg_{rm 1-x}Te, it is found to be inferior to other techniques developed. Studies of dynamical aspects of HOLZ diffraction can yield information about the dispersion surface from which a measure of composition may be obtained. This technique is evaluated for Al_{rm x}Ga_{rm 1-x} As, in which it is found to be of some use, and for Cd_{rm x}Hg _{rm 1-x}Te, in which the large Debye-Waller factor associated with mercury in discovered to render the method of little value. A number of critical voltages may be measured in medium voltage TEMs. The (111) zone axis critical voltage of Cd_{rm x}Hg _{rm 1-x}Te is found to vary significantly with x and forms the basis of an accurate technique for composition measurement in that ternary compound. Other critical voltage phenomena are investigated. In Al _{rm x}Ga_ {rm 1-x}As and other light ternaries, a non-systematic critical voltage is found to vary with x, providing a good indicator of composition. Critical voltage measurements may be made by conventional CBED or by various other techniques, which may also simultaneously yield information on the spatial variation of composition. The

Reduction of bonding resistance of two-terminal III-V/Si tandem solar cells fabricated using smart-stack technology

Science.gov (United States)

Baba, Masaaki; Makita, Kikuo; Mizuno, Hidenori; Takato, Hidetaka; Sugaya, Takeyoshi; Yamada, Noboru

2017-12-01

This paper describes a method that remarkably reduces the bonding resistance of mechanically stacked two-terminal GaAs/Si and InGaP/Si tandem solar cells, where the top and bottom cells are bonded using a Pd nanoparticle array. A transparent conductive oxide (TCO) layer, which partially covers the surface of the Si bottom cell below the electrodes of the III-V top cell, significantly enhances the fill factor (FF) and cell conversion efficiency. The partial TCO layer reduces the bonding resistance and thus, increases the FF and efficiency of InGaP/Si by factors of 1.20 and 1.11, respectively. Eventually, the efficiency exceeds 15%. Minimizing the optical losses at the bonding interfaces of the TCO layer is important in the fabrication of high-efficiency solar cells. To help facilitate this, the optical losses in the tandem solar cells are thoroughly characterized through optical simulations and experimental verifications.

Inner-sphere, outer-sphere and ternary surface complexes: a TRLFS study of the sorption process of europium(III) onto smectite

International Nuclear Information System (INIS)

Stumpf, Th.; Fanghaenel, Th.; Bauer, A.; Kim, J.I.

2002-01-01

The surface sorption process of Eu(III) onto smectite was investigated by TRLFS in the trace concentration range. With increasing pH the formation of an inner-sphere Eu(III) surface complex was observed. The differences in the spectra and the fluorescence emission lifetimes of the surface sorbed Eu(III) in presence and absence of carbonate indicate the formation of ternary clay/Eu(III)/carbonate complexes /1/. (orig.)

III-V/Active-Silicon Integration for Low-Cost High-Performance Concentrator Photovoltaics

Energy Technology Data Exchange (ETDEWEB)

Ringel, Steven [The Ohio State Univ., Columbus, OH (United States); Carlin, John A [The Ohio State Univ., Columbus, OH (United States); Grassman, Tyler [The Ohio State Univ., Columbus, OH (United States)

2018-04-17

This FPACE project was motivated by the need to establish the foundational pathway to achieve concentrator solar cell efficiencies greater than 50%. At such an efficiency, DOE modeling projected that a III-V CPV module cost of $0.50/W or better could be achieved. Therefore, the goal of this project was to investigate, develop and advance a III-V/Si mulitjunction (MJ) CPV technology that can simultaneously address the primary cost barrier for III-V MJ solar cells while enabling nearly ideal MJ bandgap profiles that can yield efficiencies in excess of 50% under concentrated sunlight. The proposed methodology was based on use of our recently developed GaAsP metamorphic graded buffer as a pathway to integrate unique GaAsP and Ga-rich GaInP middle and top junctions having bandgaps that are adjustable between 1.45 – 1.65 eV and 1.9 – 2.1 eV, respectively, with an underlying, 1.1 eV active Si subcell/substrate. With this design, the Si can be an active component sub-cell due to the semi-transparent nature of the GaAsP buffer with respect to Si as well as a low-cost alternative substrate that is amenable to scaling with existing Si foundry infrastructure, providing a reduction in materials cost and a low cost path to manufacturing at scale. By backside bonding of a SiGe, a path to exceed 50% efficiency is possible. Throughout the course of this effort, an expansive range of new understanding was achieved that has stimulated worldwide efforts in III-V/Si PV R&D that spanned materials development, metamorphic device optimization, and complete III-V/Si monolithic integration. Highlights include the demonstration of the first ideal GaP/Si interfaces grown by industry-standard MOCVD processes, the first high performance metamorphic tunnel junctions designed for III-V/Si integration, record performance of specific metamorphic sub-cell designs, the first fully integrated GaInP/GaAsP/Si double (1.7 eV/1.1 eV) and triple (1.95 eV/1.5 eV/1.1 eV) junction solar cells, the first

Effects of Ligands on a Ternary Hydroxo Complex Formation with Eu(III) in a Aqueous Solution: Comparison of a Pyridine-2,6-dicarboxylate with a Phthalate

International Nuclear Information System (INIS)

Park, K. K.; Cho, H. R.; Kim, W. H.; Jung, E. C.

2008-01-01

The interaction of a radionuclide with ligands in a groundwater influences its migration through a hydrogeological system due to a change in the characteristics of a dissolution and a sorption. Actinide ions are classified as a hard acid and strongly interact with ligands having an oxygen donor atom of a hard base such as a hydroxide, carbonate and carboxylate. These ligands reveal a large ionic bonding character. A number of experimental results on a binary complex formation of actinides have been reported. However, actinides may easily form a ternary complex by interacting simultaneously with two different ligands, since an ionic bonding does not restrict the spatial orientation of a ligand. In previous studies, a ternary hydroxo complex formation was investigated by using pyridine-2,6-dicarboxylate (PDA) or phthalate as an organic ligand and Eu(III) as an analogue of an actinide(III) ion. Although these organic ligands equally contain two carboxylate groups that interact with an Eu(III) ion, their stabilities reveal big differences. PDA is a tridentate ligand forming two 5-membered chelates, while phthalate is a bidentate ligand forming a 7-membered chelate. The latter reveals a lower stability than the former due to an angle strain. This is one of the reasons for the lower stability of the Eu(III)-phthalate than that of the Eu(III)- PDA. The difference in the stabilities of binary complexes, EuL + (L=organic ligand), influences the stabilities of the ternary hydroxo complexes, Eu(OH)L. The coordination of a phenylic or pyridine ligand can greatly enhance the fluorescence of an Eu(III) ion due to the high absorbance of a ligand by a π → π * transition and the transfer of this energy to an Eu(III) ion. These fluorescence characteristics in a binary complex system could be changed in a ternary complex. In this study, the effect of a ligand on the stability of a ternary hydroxo complex is reported by comparing the stabilities of Eu-PDA with Eu-phthalate systems

Optical analysis of a III-V-nanowire-array-on-Si dual junction solar cell.

Science.gov (United States)

Chen, Yang; Höhn, Oliver; Tucher, Nico; Pistol, Mats-Erik; Anttu, Nicklas

2017-08-07

A tandem solar cell consisting of a III-V nanowire subcell on top of a planar Si subcell is a promising candidate for next generation photovoltaics due to the potential for high efficiency. However, for success with such applications, the geometry of the system must be optimized for absorption of sunlight. Here, we consider this absorption through optics modeling. Similarly, as for a bulk dual-junction tandem system on a silicon bottom cell, a bandgap of approximately 1.7 eV is optimum for the nanowire top cell. First, we consider a simplified system of bare, uncoated III-V nanowires on the silicon substrate and optimize the absorption in the nanowires. We find that an optimum absorption in 2000 nm long nanowires is reached for a dense array of approximately 15 nanowires per square micrometer. However, when we coat such an array with a conformal indium tin oxide (ITO) top contact layer, a substantial absorption loss occurs in the ITO. This ITO could absorb 37% of the low energy photons intended for the silicon subcell. By moving to a design with a 50 nm thick, planarized ITO top layer, we can reduce this ITO absorption to 5%. However, such a planarized design introduces additional reflection losses. We show that these reflection losses can be reduced with a 100 nm thick SiO 2 anti-reflection coating on top of the ITO layer. When we at the same time include a Si 3 N 4 layer with a thickness of 90 nm on the silicon surface between the nanowires, we can reduce the average reflection loss of the silicon cell from 17% to 4%. Finally, we show that different approximate models for the absorption in the silicon substrate can lead to a 15% variation in the estimated photocurrent density in the silicon subcell.

Semiconducting III-V compounds

CERN Document Server

Hilsum, C; Henisch, Heinz R

1961-01-01

Semiconducting III-V Compounds deals with the properties of III-V compounds as a family of semiconducting crystals and relates these compounds to the monatomic semiconductors silicon and germanium. Emphasis is placed on physical processes that are peculiar to III-V compounds, particularly those that combine boron, aluminum, gallium, and indium with phosphorus, arsenic, and antimony (for example, indium antimonide, indium arsenide, gallium antimonide, and gallium arsenide).Comprised of eight chapters, this book begins with an assessment of the crystal structure and binding of III-V compounds, f

Ternary Oxides in the TiO2-ZnO System as Efficient Electron-Transport Layers for Perovskite Solar Cells with Efficiency over 15.

Science.gov (United States)

Yin, Xiong; Xu, Zhongzhong; Guo, Yanjun; Xu, Peng; He, Meng

2016-11-02

Perovskite solar cells, which utilize organometal-halide perovskites as light-harvesting materials, have attracted great attention due to their high power conversion efficiency (PCE) and potentially low cost in fabrication. A compact layer of TiO 2 or ZnO is generally applied as electron-transport layer (ETL) in a typical perovskite solar cell. In this study, we explored ternary oxides in the TiO 2 -ZnO system to find new materials for the ETL. Compact layers of titanium zinc oxides were readily prepared on the conducting substrate via spray pyrolysis method. The optical band gap, valence band maximum and conduction band minimum of the ternary oxides varied significantly with the ratio of Ti to Zn, surprisingly, in a nonmonotonic way. When a zinc-rich ternary oxide was applied as ETL for the device, a PCE of 15.10% was achieved, comparable to that of the device using conventional TiO 2 ETL. Interestingly, the perovskite layer deposited on the zinc-rich ternary oxide is stable, in sharp contrast with that fabricated on a ZnO layer, which will turn into PbI 2 readily when heated. These results indicate that potentially new materials with better performance can be found for ETL of perovskite solar cells in ternary oxides, which deserve more exploration.

pH-Specific structural speciation of the ternary V(V)-peroxido-betaine system: a chemical reactivity-structure correlation.

Science.gov (United States)

Gabriel, C; Kioseoglou, E; Venetis, J; Psycharis, V; Raptopoulou, C P; Terzis, A; Voyiatzis, G; Bertmer, M; Mateescu, C; Salifoglou, A

2012-06-04

Vanadium involvement in cellular processes requires deep understanding of the nature and properties of its soluble and bioavailable forms arising in aqueous speciations of binary and ternary systems. In an effort to understand the ternary vanadium-H(2)O(2)-ligand interactions relevant to that metal ion's biological role, synthetic efforts were launched involving the physiological ligands betaine (Me(3)N(+)CH(2)CO(2)(-)) and H(2)O(2). In a pH-specific fashion, V(2)O(5), betaine, and H(2)O(2) reacted and afforded three new, unusual, and unique compounds, consistent with the molecular formulation K(2)[V(2)O(2)(O(2))(4){(CH(3))(3)NCH(2)CO(2))}]·H(2)O (1), (NH(4))(2)[V(2)O(2)(O(2))(4){(CH(3))(3)NCH(2)CO(2))}]·0.75H(2)O (2), and {Na(2)[V(2)O(2)(O(2))(4){(CH(3))(3)NCH(2)CO(2))}(2)]}(n)·4nH(2)O (3). All complexes 1-3 were characterized by elemental analysis; UV/visible, FT-IR, Raman, and NMR spectroscopy in solution and the solid state; cyclic voltammetry; TGA-DTG; and X-ray crystallography. The structures of 1 and 2 reveal the presence of unusual ternary dinuclear vanadium-tetraperoxido-betaine complexes containing [(V(V)═O)(O(2))(2)] units interacting through long V-O bonds. The two V(V) ions are bridged through the oxygen terminal of one of the peroxide groups bound to the vanadium centers. The betaine ligand binds only one of the two V(V) ions. In the case of the third complex 3, the two vanadium centers are not immediate neighbors, with Na(+) ions (a) acting as efficient oxygen anchors and through Na-O bonds holding the two vanadium ions in place and (b) providing for oxygen-containing ligand binding leading to a polymeric lattice. In 1 and 3, interesting 2D (honeycomb) and 1D (zigzag chains) topologies of potassium nine-coordinate polyhedra (1) and sodium octahedra (3), respectively, form. The collective physicochemical properties of the three ternary species 1-3 project the chemical role of the low molecular mass biosubstrate betaine in binding V(V

Formation of binary and ternary complexes of mercaptobenzimidazoles with lanthanides in presence of aminopolycarboxylic acids

Energy Technology Data Exchange (ETDEWEB)

Seshi Reddy, P; Manwal, D D; Chandra Pal, A V [Osmania Univ., Hyderabad (India). Dept. of Chemistry

1994-05-01

The formation constants of 1:1 and 1:2 binary Ln (III)-2-mercaptomethylbenzimidazole (MMB), Ln (III)-2-mercapto-ethylbenzimidazole (MEB) and 1:1:1 ternary [Ln (III)-A-MMB], [Ln (III)-A-MEB] chelates [where Ln(III) = Pr, Nd, Gd, Dy and Y; A = iminodiacetic acid (IMDA), hydroxyethyliminodiacetic acid (HIMDA) and nitrilotriacetic acid (NTA)] have been determined pH-metrically in 50% (v/v) aqueous ethanol medium at 30 degC and I = 0.1 M (NaClO{sub 4}). The ligands MMB and MEB coordinates as secondary ligands in presence of IMDA, HIMDA and NTA with metal ions. (author). 11 refs., 2 figs., 2 tabs.

5He, 7He, and 8Li (E*=2.26 MeV) intermediate ternary particles in the spontaneous fission of 252Cf

International Nuclear Information System (INIS)

Kopatch, Yu.N.; Mutterer, M.; Schwalm, D.; Thirolf, P.; Goennenwein, F.

2002-01-01

The neutron-unstable odd-N isotopes 5 He, 7 He, and 8 Li (in its excited state of E*=2.26 MeV) were measured to show up as short-lived (τ≅10 -21 -10 -20 s) intermediate light charged particles (LCPs) in ternary fission of 252 Cf. For the study a high-efficiency angular correlation measurement between neutrons, LCPs, and main fission fragments has been performed. The evidence for the ternary 5 He and 7 He particles (lifetimes: 1x10 -21 s, and 4x10 -21 s, respectively) was disclosed from the measured angular distributions of their decay neutrons focused by the emission in flight towards the direction of motion of 4 He and 6 He ternary particles. Similarly, neutrons observed to be peaked around Li-particle motion could be attributed to the decay of the second excited state at E*=2.26 MeV (lifetime: 2x10 -20 s) of 8 Li. The fractional yields of the intermediate 5 He and 7 He ternary fission modes relative to the 'true' ternary 4 He and 6 He modes, respectively, were determined to be 0.21(5) for both cases. The mean energy of the 4 He residues resulting from the 5 He decay was determined to be 12.4(3) MeV, compared to 15.7(2) MeV for all ternary α particles registered, and to 16.4(3) MeV for the true ternary α particles. The mean energy of the 6 He residues from the 7 He decay is 11.0(15) MeV, compared to 12.3(5) MeV for all ternary 6 He particles. The population of 8 Li* was deduced to be 0.06(2) relative to Li ternary fission, and 0.33(20) relative to the yield of particle stable 8 Li. The perspective of using the observed intermediate LCPs for probing the ternary scission configuration in 252 Cf fission with the aid of trajectory calculations is briefly discussed

5He, 7He and 8Li (E=2.26 MeV) intermediate ternary particles in the spontaneous fission of 252Cf

International Nuclear Information System (INIS)

Kopatch, Yu. N.; Goennenwein, F.

2002-02-01

The neutron-unstable odd-N isotopes 5 He, 7 He and 8 Li (in its excited state of E * = 2.26 MeV) were measured to show up as short-lived intermediate light-charged-particles (LCP) in ternary fission of 252 Cf. For the study a high-efficiency angular correlation measurement between neutrons, LCPs and main fission fragments has been performed. The evidence for the ternary 5 He and 7 He particles (lifetimes: 1 x 10 -21 s, and 4 x 10 -21 s, respectively) was disclosed from the measured angular distributions of their decay neutrons focused by the emission in flight towards the direction of motion of 4 He and 6 He ternary particles. Similarly, neutrons observed to be peaked around Li-particle motion could be attributed to the decay of the second excited state at E * = 2.26 MeV (lifetime: 2 x 10 -20 s) of 8 Li. The fractional yields of the intermediate 5 He and 7 He ternary fission modes relative to the ''true'' ternary 4 He and 6 He modes, respectively, were determined to be 0.21(5) for both cases. The mean energy of the 4 He residues resulting from the 5 He decay was determined to be 12.4(3) MeV, compared to 15.7(2) MeV for all ternary α-particles registered, and to 16.4(3) MeV for the true ternary α-particles. The mean energy of the 6 He residues from the 7 He decay is 11.0(15) MeV, compared to 12.3(5) MeV for all ternary 6 He particles. The population of 8 Li * was deduced to be 0.06(2) relative to Li ternary fission, and 0.33(20) relative to the yield of particle stable 8 Li. The perspective of using the observed intermediate LCPs for probing the ternary scission configuration in 252 Cf fission with the aid of trajectory calculations is briefly discussed. (orig.)

High Performing Ternary Solar Cells through Förster Resonance Energy Transfer between Nonfullerene Acceptors.

Science.gov (United States)

Yang, Lei; Gu, Wenxing; Hong, Ling; Mi, Yang; Liu, Feng; Liu, Ming; Yang, Yufei; Sharma, Bigyan; Liu, Xinfeng; Huang, Hui

2017-08-16

Nonradiative Förster resonance energy transfer (FRET) is an important mechanism of organic solar cells, which can improve the exciton migration over a long distance, resulting in improvement of efficiency of solar cells. However, the current observations of FRET are very limited, and the efficiencies are less than 9%. In this study, FRET effect was first observed between two nonfullerene acceptors in ternary solar cells, which improved both the absorption range and exciton harvesting, leading to the dramatic enhancement in the short circuit current and power conversion efficiency. Moreover, this strategy is proved to be a versatile platform for conjugated polymers with different bandgaps, resulting in a remarkable efficiency of 10.4%. These results demonstrated a novel method to enhance the efficiency of organic soar cells.

GaAs Solar Cells on V-Grooved Silicon via Selective Area Growth: Preprint

Energy Technology Data Exchange (ETDEWEB)

Warren, Emily L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Jain, Nikhil [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Tamboli, Adele C [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Vaisman, Michelle [Yale University; Li, Qiang [Hong Kong University of Science and Technology; Lau, Kei May [Hong Kong University of Science and Technology

2017-08-31

Interest in integrating III-Vs onto Si has recently resurged as a promising pathway towards high-efficiency, low-cost tandem photovoltaics. Here, we present a single junction GaAs solar cell grown monolithically on polished Si (001) substrates using V-grooves, selective area growth, and aspect ratio trapping to mitigate defect formation without the use of expensive, thick graded buffers. The GaAs is free of antiphase domains and maintains a relatively low TDD of 4x107 cm-2, despite the lack of a graded buffer. This 6.25 percent-efficient demonstration solar cell shows promise for further improvements to III-V/Si tandems to enable cost-competitive photovoltaics.

Theoretical modeling and optimization of III-V GaInP/GaAs/Ge monolithic triple-junction solar cells

International Nuclear Information System (INIS)

Leem, Jung Woo; Yu, Jae Su; Kim, Jong Nam; Noh, Sam Kyu

2014-01-01

We design and optimize monolithic III-V GaInP/GaAs/Ge triple-junction (TJ) solar cells by using a commercial software Silvaco ATLAS simulator to obtain the maximum short-circuit current density J sc . The maximum J sc , which is a current matching value between the GaInP top and GaAs middle subcells, can be determined by varying the base thicknesses of the GaInP top and GaAs middle subcells. From the numerical simulation results, a matched maximum J sc value of 13.92 mA/cm 2 is obtained at base thicknesses of 0.57 μm and 3 μm for the GaInP top and GaAs middle subcells, respectively, under 1-sun air mass 1.5 global spectrum illumination, leading to a high power conversion efficiency of 30.72%. The open-circuit voltage and the fill factor are 2.55 V and 86.55%, respectively. For the optimized cell structure, the external quantum efficiency and the photogeneration rate distributions are also investigated. To obtain efficient antireflection coatings (ARCs), we perform optical reflectance calculations by using a rigorous coupled-wave analysis method. For this, a silicon oxide/titanium oxide double-layer is used as an ARC on the TJ solar cell.

Theoretical modeling and optimization of III-V GaInP/GaAs/Ge monolithic triple-junction solar cells

Energy Technology Data Exchange (ETDEWEB)

Leem, Jung Woo; Yu, Jae Su [Kyung Hee University, Yongin (Korea, Republic of); Kim, Jong Nam [Pukyung National University, Pusan (Korea, Republic of); Noh, Sam Kyu [Korea Research Institute of Standards and Science, Daejon (Korea, Republic of)

2014-05-15

We design and optimize monolithic III-V GaInP/GaAs/Ge triple-junction (TJ) solar cells by using a commercial software Silvaco ATLAS simulator to obtain the maximum short-circuit current density J{sub sc}. The maximum J{sub sc}, which is a current matching value between the GaInP top and GaAs middle subcells, can be determined by varying the base thicknesses of the GaInP top and GaAs middle subcells. From the numerical simulation results, a matched maximum J{sub sc} value of 13.92 mA/cm{sup 2} is obtained at base thicknesses of 0.57 μm and 3 μm for the GaInP top and GaAs middle subcells, respectively, under 1-sun air mass 1.5 global spectrum illumination, leading to a high power conversion efficiency of 30.72%. The open-circuit voltage and the fill factor are 2.55 V and 86.55%, respectively. For the optimized cell structure, the external quantum efficiency and the photogeneration rate distributions are also investigated. To obtain efficient antireflection coatings (ARCs), we perform optical reflectance calculations by using a rigorous coupled-wave analysis method. For this, a silicon oxide/titanium oxide double-layer is used as an ARC on the TJ solar cell.

Solar Flares, Type III Radio Bursts, Coronal Mass Ejections, and Energetic Particles

Science.gov (United States)

Cane, Hilary V.; Erickson, W. C.; Prestage, N. P.; White, Nicholas E. (Technical Monitor)

2002-01-01

In this correlative study between greater than 20 MeV solar proton events, coronal mass ejections (CMEs), flares, and radio bursts it is found that essentially all of the proton events are preceded by groups of type III bursts and all are preceded by CMEs. These type III bursts (that are a flare phenomenon) usually are long-lasting, intense bursts seen in the low-frequency observations made from space. They are caused by streams of electrons traveling from close to the solar surface out to 1 AU. In most events the type III emissions extend into, or originate at, the time when type II and type IV bursts are reported (some 5 to 10 minutes after the start of the associated soft X-ray flare) and have starting frequencies in the 500 to approximately 100 MHz range that often get lower as a function of time. These later type III emissions are often not reported by ground-based observers, probably because of undue attention to type II bursts. It is suggested to call them type III-1. Type III-1 bursts have previously been called shock accelerated (SA) events, but an examination of radio dynamic spectra over an extended frequency range shows that the type III-1 bursts usually start at frequencies above any type II burst that may be present. The bursts sometimes continue beyond the time when type II emission is seen and, furthermore, sometimes occur in the absence of any type II emission. Thus the causative electrons are unlikely to be shock accelerated and probably originate in the reconnection regions below fast CMEs. A search did not find any type III-1 bursts that were not associated with CMEs. The existence of low-frequency type III bursts proves that open field lines extend from within 0.5 radius of the Sun into the interplanetary medium (the bursts start above 100 MHz, and such emission originates within 0.5 solar radius of the solar surface). Thus it is not valid to assume that only closed field lines exist in the flaring regions associated with CMEs and some

Possible Mechanisms of Ternary Fission in the 197Au+197 Au System at 15 AMeV

International Nuclear Information System (INIS)

Jun-Long, Tian; Xian, Li; Shi-Wei, Yan; Xi-Zhen, Wu; Zhu-Xia, Li

2009-01-01

Ternary fission in 197 Au+ 197 Au collisions at 15 A MeV is investigated by using the improved quantum molecular dynamical (ImQMD) model. The experimental mass distributions for each of the three fragments are reproduced for the first time without any freely adjusting parameters. The mechanisms of ternary fission in central and semi-central collisions are dynamically studied. In direct prolate ternary fission, two necks are found to be formed almost simultaneously and rupture sequentially in a very short time interval. Direct oblate ternary fission is a very rare fission event, in which three necks are formed and rupture simultaneously, forming three equally sized fragments along space-symmetric directions in the reaction plane. In sequential ternary fission a binary division is followed by another binary fission event after hundreds of fm/c. (nuclear physics)

Mechanism of ternary breakup in the reaction 197Au+197Au at 15A MeV

International Nuclear Information System (INIS)

Tian Junlong; Wu Xizhen; Li Zhuxia; Zhao Kai; Zhang Yingxun; Li Xian; Yan Shiwei

2010-01-01

The mechanism of the ternary breakup of the very heavy system 197 Au+ 197 Au at an energy of 15A MeV has been studied by using the improved quantum molecular dynamics model. The calculation results reproduce the characteristic features in ternary breakup events explored in a series of experiments; i.e., the masses of three fragments are comparable in size and the very fast, nearly collinear breakup of the colliding system is dominant in the ternary breakup events. Further, the evolution of the time scales of different ternary reaction modes and the behavior of mass distributions of three fragments with impact parameters are studied. The time evolution of the configurations of the composite reaction systems is also studied. We find that for most of the ternary breakup events with the features found in the experiments, the configuration of the composite system has two-preformed-neck shape. The study shows that those ternary breakup events having the characteristic features found in the experiments happen at relatively small impact parameter reactions, but not at peripheral reactions. The ternary breakup reaction at peripheral reactions belongs to binary breakup with a neck emission.

Influence of light waves on the thermoelectric power under large magnetic field in III-V, ternary and quaternary materials

Energy Technology Data Exchange (ETDEWEB)

Ghatak, K.P. [Department of Electronic Science, The University of Calcutta, 92, Acharya Prafulla Chandra Road, Kolkata 700 009 (India); Bhattacharya, S. [Post Graduate Department of Computer Science, St. Xavier' s College, 30 Park Street, Kolkata 700 016 (India); Pahari, S. [Department of Administration, Jadavpur University, Kolkata 700 032 (India); De, D. [Department of Computer Science and Engineering, West Bengal University of Technology, B. F. 142, Sector I, Salt Lake, Kolkata 700 064 (India); Ghosh, S.; Mitra, M. [Department of Electronics and Telecommunication Engineering, Bengal Engineering and Science University, Howrah 711 103 (India)

2008-04-15

We study theoretically the influence of light waves on the thermoelectric power under large magnetic field (TPM) for III-V, ternary and quaternary materials, whose unperturbed energy-band structures, are defined by the three-band model of Kane. The solution of the Boltzmann transport equation on the basis of this newly formulated electron dispersion law will introduce new physical ideas and experimental findings in the presence of external photoexcitation. It has been found by taking n-InAs, n-InSb, n-Hg{sub 1-x}Cd{sub x}Te and n-In{sub 1-x}Ga{sub x}As{sub y}P{sub 1-y} lattice matched to InP as examples that the TPM decreases with increase in electron concentration, and increases with increase in intensity and wavelength, respectively in various manners. The strong dependence of the TPM on both light intensity and wavelength reflects the direct signature of light waves that is in direct contrast as compared with the corresponding bulk specimens of the said materials in the absence of external photoexcitation. The rate of change is totally band-structure dependent and is significantly influenced by the presence of the different energy-band constants. The well-known result for the TPM for nondegenerate wide-gap materials in the absence of light waves has been obtained as a special case of the present analysis under certain limiting conditions and this compatibility is the indirect test of our generalized formalism. Besides, we have also suggested the experimental methods of determining the Einstein relation for the diffusivity:mobility ratio, the Debye screening length and the electronic contribution to the elastic constants for materials having arbitrary dispersion laws. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

Fluorometric determination of aluminium (III) and cadmium (II) by solvent extraction of the ternary complex composed of metal ion, 8-hydroxy-5-quinolinesulfonic acid, and methyltrioctylammonium ion

International Nuclear Information System (INIS)

Kondoh, Yukihiro; Kataoka, Masamitsu; Kambara, Tomihito

1982-01-01

A fluorometric micro determination of aluminium (III) and cadmium (II) using the formation of metal-8-hydroxy-5-quinolinesulfonic acid-capriquat (methyltrioctylammonium) ternary complex is described. These complexes are easily extracted into chloroform phase and the extract emits a strong fluorescence. Spectra of aluminium (III) and cadmium (II) ternary complexes have the excitation maximum at 396 nm and 400 nm, and emission maximum at 501 nm and 524 nm, respectively. Fluorescence intensity of the aluminium (III) and cadmium (II) ternary complexes extracted into chloroform showed the constant and maximum values in the pH range of aqueous phase from 5.3 to 8.5 and 8.1 to 8.5, respectively. The calibration curves for aluminium (III) and cadmium (II) show good proportionality int the concentration range from 0.5 to 5.0 and 1.0 to 50.0 μg, respectively. The relative standard deviation observed with four measurements was found to be 1.8% for 0.5 μg of aluminium (III) and 1.1% for 10.0 μg of cadmium (II). The effect of diverse ions is studied and a 25-fold amount of Cu(II), Ni(II), Fe(II), Fe(III) in weight gave errors, however, the interferences were easily eliminated by the addition of appropriate masking agent. In the determination of cadmium (II), an equal amount of Co(II), Ni(II), Mn(II), Fe(III) and twice amount of Al(III) gave negative errors, however, the interference of Fe(III) and Al(III) were also eliminated as above. (author)

Solvent extraction of anionic chelate complexes of lanthanum(III), europium(III), lutetium(III), scandium(III), and indium(III) with 2-thenoyltrifluoroacetone as ion-pairs with tetrabutylammonium ions

International Nuclear Information System (INIS)

Noro, Junji; Sekine, Tatsuya.

1992-01-01

The solvent extraction of lanthanum(III), europium(III), lutetium(III), scandium(III), and indium(III) in 0.1 mol dm -3 sodium nitrate solutions with 2-thenoyltrifluoroacetone (Htta) in the absence and presence of tetrabutylammonium ions (tba + ) into carbon tetrachloride was measured. The extraction of lanthanum(III), europium(III), and lutetium(III) was greatly enhanced by the addition of tba + ; this could be explained in terms of the extraction of a ternary complex, M(tta) 4 - tba + . However, the extractions of scandium(III) and indium(III) were nearly the same when tba + was added. The data were treated on the basis of the formation equilibrium of the ternary complex from the neutral chelate, M(tta) 3 , with the extracted ion-pairs of the reagents, tta - tba + , in the organic phase. It was concluded that the degree of association of M(tta) 3 with the ion-pair, tta - tba + , is greater in the order La(tta) 3 ≅ Eu(tta) 3 > Lu(tta) 3 , or that the stability of the ternary complex in the organic phase is higher in the order La(tta) 4 - tba + ≅ Eu(tta) 4 - tba + > Lu(tta) 4 - tba + . This is similar to those of adduct metal chelates of Htta with tributylphosphate (TBP) in synergistic extraction systems. (author)

Exploiting strain to enhance the Bi incorporation in GaAs-based III/V semiconductors using MOVPE

Science.gov (United States)

Nattermann, L.; Ludewig, P.; Sterzer, E.; Volz, K.

2017-07-01

Bi containing III/V semiconductors are frequently mentioned for their importance as part of the next generation of optoelectronic devices. Bi containing ternary and quaternary materials like Ga(AsBi), Ga(NAsBi) or Ga(PAsBi) are promising candidates to meet the requirements for new laser structures for telecommunications and solar cell applications. However, in previous studies it was determined that the incorporation of sufficient amounts of Bi still poses a challenge, especially when using MOVPE (metalorganic vapour phase epitaxy) as the growth technique. In order to figure out which mechanisms are responsible for the limitation of Bi incorporation, this work deals with the question of whether there is a relationship between strain, induced by the large Bi atoms, and the saturation level of Bi incorporation in Ga(AsBi). Ga(NAsBi) structures were grown by MOVPE at a low temperature, 400 °C, and compared to Ga(PAsBi) as well as Ga(AsBi) growth. By using the two group V atoms P and N, which have a smaller covalent radius than Bi, the effect of local strain compensation was investigated systematically. The comparison of Bi incorporation in the two quaternary materials systems proved the importance of local strain for the limitation of Bi incorporation, in addition to other effects, like Bi surface coverage and hydrocarbon groups at the growth surface. This, of course, also opens up ways to strain-state-engineer the Bi incorporation in semiconductor alloys.

III-V microelectronics

CERN Document Server

Nougier, JP

1991-01-01

As is well known, Silicon widely dominates the market of semiconductor devices and circuits, and in particular is well suited for Ultra Large Scale Integration processes. However, a number of III-V compound semiconductor devices and circuits have recently been built, and the contributions in this volume are devoted to those types of materials, which offer a number of interesting properties. Taking into account the great variety of problems encountered and of their mutual correlations when fabricating a circuit or even a device, most of the aspects of III-V microelectronics, from fundamental p

Isothermal section of the Y-Co-V ternary system at 500 deg. C

International Nuclear Information System (INIS)

Wei, X.X.; Yan, J.L.; Du, H.W.; Wu, C.L.; Zhou, K.W.; Zhuang, Y.H.; Li, J.Q.

2011-01-01

Research highlights: → The isothermal section of the Y-Co-V system at 500 deg. C has been established. → Only one ternary compound YV x Co 12-x was found in this system and it exhibits a linear homogeneity range for 1.30 ≤ x ≤ 3.64. → The maximum solid solubilities of V in the compounds Y 2 Co 17 , Y 2 Co 7 , YCo 3 , YCo 2 and Y 3 Co are about 10, 1.0, 3.0, 4.0 and 4.0 at.%, respectively. - Abstract: The isothermal section of the Y-Co-V system at 500 deg. C has been investigated by X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy. Only one ternary compound YV x Co 12-x with a homogeneity range of 1.30 ≤ x ≤3.64 was found in this system. The maximum solid solubilities of V in Y 2 Co 17 , Y 2 Co 7 , YCo 3 , YCo 2 and Y 3 Co are about 10.0, 1.0, 3.0, 4.0 and 4.0 at.% V, respectively. The compounds VCo and VCo 3 have a homogeneity range of 46-66 at.% V and 22-30 at.% V, respectively. The maximum solid solubility of Y in VCo is about 2.0 at.% Y.

Comparative study of binary and ternary complexes of some rare earths

International Nuclear Information System (INIS)

Makhijani, S.D.; Sangal, S.P.

1978-01-01

Modified form of Irving and Rossotti's pH titration technique has been used to evaluate and compare the stability constants of the binary and ternary complexes of Sc(III), Y(III), La(III), Pr(III), Nd(III) and Sm(III) at 30 0 at an ionic strength of 0.2M NaClO 4 . For the study of ternary complexes, nitrilotriacetic acid has been used as a primary ligand and polyhydroxy phenols i.e. pyrocatechol (PYC), pyrogallol (PYG) and gallic acid (GA) as secondary ligands. The stability constants of the binary complexes were found to be more than those of the corresponding ternary complexes which can reasonably be explained on the basis of electrostatic force between primary complex (metal in the case of binary complex) and secondary ligand, and space available to accommodate the secondary ligand. The stability decreases with the increase in ionic radii, i.e. Sc(III)>Y(III)>Sm(III)>Nd(III)>Pr(III)>La(III). In terms of secondary ligand, it follows the order PYC>GA>PYG. Rare earths form only 1:1 binary complex, and 1:1:1 mixed ligand complex in all the cases. (author)

From Large-Scale Synthesis to Lighting Device Applications of Ternary I-III-VI Semiconductor Nanocrystals: Inspiring Greener Material Emitters.

Science.gov (United States)

Chen, Bingkun; Pradhan, Narayan; Zhong, Haizheng

2018-01-18

Quantum dots with fabulous size-dependent and color-tunable emissions remained as one of the most exciting inventories in nanomaterials for the last 3 decades. Even though a large number of such dot nanocrystals were developed, CdSe still remained as unbeatable and highly trusted lighting nanocrystals. Beyond these, the ternary I-III-VI family of nanocrystals emerged as the most widely accepted greener materials with efficient emissions tunable in visible as well as NIR spectral windows. These bring the high possibility of their implementation as lighting materials acceptable to the community and also to the environment. Keeping these in mind, in this Perspective, the latest developments of ternary I-III-VI nanocrystals from their large-scale synthesis to device applications are presented. Incorporating ZnS, tuning the composition, mixing with other nanocrystals, and doping with Mn ions, light-emitting devices of single color as well as for generating white light emissions are also discussed. In addition, the future prospects of these materials in lighting applications are also proposed.

Low-Frequency Type III Bursts and Solar Energetic Particle Events

Science.gov (United States)

Gopalswamy, Nat; Makela, Pertti

2010-01-01

We analyzed the coronal mass ejections (CMEs), flares, and type 11 radio bursts associated with a set of six low frequency (15 min) normally used to define these bursts. All but one of the type III bursts was not associated with a type 11 burst in the metric or longer wavelength domains. The burst without type 11 burst also lacked a solar energetic particle (SEP) event at energies >25 MeV. The 1-MHz duration of the type III burst (28 min) is near the median value of type III durations found for gradual SEP events and ground level enhancement (GLE) events. Yet, there was no sign of SEP events. On the other hand, two other type III bursts from the same active region had similar duration but accompanied by WAVES type 11 bursts; these bursts were also accompanied by SEP events detected by SOHO/ERNE. The CMEs were of similar speeds and the flares are also of similar size and duration. This study suggests that the type III burst duration may not be a good indicator of an SEP event.

Quantum Dot Sensitized Solar Cells Based on Ternary Metal Oxide Nanowires

Energy Technology Data Exchange (ETDEWEB)

Wang, Wenyong [Univ. of Wyoming, Laramie, WY (United States); Tang, Jinke [Univ. of Wyoming, Laramie, WY (United States); Dahnovsky, Yuri [Univ. of Wyoming, Laramie, WY (United States); Pikal, Jon M [Univ. of Wyoming, Laramie, WY (United States); Chien, TeYu [Univ. of Wyoming, Laramie, WY (United States)

2017-11-03

In Phase I of this project we investigate quantum dot sensitized solar cells (QDSSCs) based on ternary metal oxide nanowires and study the physical and chemical mechanisms that govern device operation. Our research has the following five objectives: (1) synthesis of ternary metal oxide nanowires, (2) synthesis of QDs and exploration of non-solution based QD deposition methods, (3) physical and electro-optical characterizations of fabricated solar devices, (4) device modeling and first-principle theoretical study of transport physics, and (5) investigation of long-term stability issues of QD sensitized solar cells. In Phase II of this project our first major research goal is to investigate magnetically doped quantum dots and related spin polarization effect, which could improve light absorption and suppress electron relaxation in the QDs. We will utilize both physical and chemical methods to synthesize these doped QDs. We will also study magnetically modified nanowires and introduce spin-polarized transport into QDSSCs, and inspect its impact on forward electron injection and back electron transfer processes. Our second goal is to study novel solid-state electrolytes for QDSSCs. Specifically, we will inspect a new type of polymer electrolytes based on a modified polysulfide redox couple, and examine the effect of their electrical properties on QDSSC performance. These solid-state electrolytes could also be used as filler materials for in situ sample fracturing in STM and enable cross-sectional interface examination of QD/nanowire structures. Our third research goal is to examine the interfacial properties such as energy level alignment at QD/nanowire interfaces using the newly developed Cross-sectional Scanning Tunneling Microscopy and Spectroscopy technique for non-cleavable materials. This technique allows a direct probing of band structures and alignment at device interfaces, which could generate important insight into the mechanisms that govern QDSSC operation

Hybrid III-V/silicon lasers

Science.gov (United States)

Kaspar, P.; Jany, C.; Le Liepvre, A.; Accard, A.; Lamponi, M.; Make, D.; Levaufre, G.; Girard, N.; Lelarge, F.; Shen, A.; Charbonnier, P.; Mallecot, F.; Duan, G.-H.; Gentner, J.-.; Fedeli, J.-M.; Olivier, S.; Descos, A.; Ben Bakir, B.; Messaoudene, S.; Bordel, D.; Malhouitre, S.; Kopp, C.; Menezo, S.

2014-05-01

The lack of potent integrated light emitters is one of the bottlenecks that have so far hindered the silicon photonics platform from revolutionizing the communication market. Photonic circuits with integrated light sources have the potential to address a wide range of applications from short-distance data communication to long-haul optical transmission. Notably, the integration of lasers would allow saving large assembly costs and reduce the footprint of optoelectronic products by combining photonic and microelectronic functionalities on a single chip. Since silicon and germanium-based sources are still in their infancy, hybrid approaches using III-V semiconductor materials are currently pursued by several research laboratories in academia as well as in industry. In this paper we review recent developments of hybrid III-V/silicon lasers and discuss the advantages and drawbacks of several integration schemes. The integration approach followed in our laboratory makes use of wafer-bonded III-V material on structured silicon-on-insulator substrates and is based on adiabatic mode transfers between silicon and III-V waveguides. We will highlight some of the most interesting results from devices such as wavelength-tunable lasers and AWG lasers. The good performance demonstrates that an efficient mode transfer can be achieved between III-V and silicon waveguides and encourages further research efforts in this direction.

Probability of ternary fission of 93Nb andnat Ag nuclei induced by 0.8-1.8 GeV photons

International Nuclear Information System (INIS)

Lima, D.A. de; Milomen, W.C.C.; Tavares, O.A.P.

1989-01-01

The yields of ternary fission of 93 Nb and nat Ag nuclei induced by bremsstrahlung photons of 0.8, 1.0, 1.4 and 1.8 GeV end-point energies have been measured by using the 2 Π-forward geometry with thick target metal foils in contact with makrofol polycarbonate sheets as fission-track detectors. Absolute mean cross sections per photon in the range 0.8-1.8 GeV have been obtained as 0.3 ± 0.3 μb and 0.5 ± μb, respectively, for 93 Nb and nat Ag nuclei. These correspond to a probability of ternary fission of approx. 10 -5 for both nuclei. Results are discussed and compared with previous ternary fission data obtained for nuclei of A [pt

Investigation of the extraction equilibrium of ternary ionassociation complex of thallium(III) with iodo-nitro-tetrazolium chlorid

International Nuclear Information System (INIS)

Alexandrov, A.; Dimitrov, A.

1976-01-01

The extraction equilibrium of the ternary ion-association complex of iodo-nitro-tetrazolium [3-(4-iodophenyl)2-(4-nitrophenyl)-5-phenyltetrazolium chloride] with the chlorocomplex of thallium(III) is investigated radiochemically. The molar ratio of the ion-associate is found to be 1:1, the association constant has a value of 3.2x10 3 in aqueous solution and the distribution constant is 8.9. The extraction constant which gives a quantitative characterization of the equilibrium is 2.3x10 4 . From the investigation performed it can be concluded that a quite satisfactory extraction of thallium(III) by means of iodo-nitro-tetrazole in benzene can be carried out. The extraction constant has a relatively high value which allows to use this system conveniently for the extraction-photometric determination of thallium(III). (T.C.)

Regulating Molecular Aggregations of Polymers via Ternary Copolymerization Strategy for Efficient Solar Cells.

Science.gov (United States)

Wang, Qian; Wang, Yingying; Zheng, Wei; Shahid, Bilal; Qiu, Meng; Wang, Di; Zhu, Dangqiang; Yang, Renqiang

2017-09-20

For many high-performance photovoltaic materials in polymer solar cells (PSCs), the active layers usually need to be spin-coated at high temperature due to the strong intermolecular aggregation of donor polymers, which is unfavorable in device repeatability and large-scale PSC printing. In this work, we adopted a ternary copolymerization strategy to regulate polymer solubility and molecular aggregation. A series of D-A 1 -D-A 2 random polymers based on different acceptors, strong electron-withdrawing unit ester substituted thieno[3,4-b]thiophene (TT-E), and highly planar dithiazole linked TT-E (DTzTT) were constructed to realize the regulation of molecular aggregation and simplification of device fabrication. The results showed that as the relative proportion of TT-E segment in the backbone increased, the absorption evidently red-shifted with a gradually decreased aggregation in solution, eventually leading to the active layers that can be fabricated at low temperature. Furthermore, due to the excellent phase separation and low recombination, the optimized solar cells based on the terpolymer P1 containing 30% of TT-E segment exhibit high power conversion efficiency (PCE) of 9.09% with a significantly enhanced fill factor up to 72.86%. Encouragingly, the photovoltaic performance is insensitive to the fabrication temperature of the active layer, and it still could maintain high PCE of 8.82%, even at room temperature. This work not only develops the highly efficient photovoltaic materials for low temperature processed PSCs through ternary copolymerization strategy but also preliminarily constructs the relationship between aggregation and photovoltaic performance.

Investigation of transient photoresponse of WSSe ternary alloy crystals

Science.gov (United States)

Chauhan, Payal; Solanki, G. K.; Tannarana, Mohit; Pataniya, Pratik; Patel, K. D.; Pathak, V. M.

2018-05-01

Transition metal chalcogenides have been studied intensively in recent time due to their tunability of electronic properties by compositional change, alloying and by transforming bulk material into crystalline 2D structure. These changes lead to the development of verities of next generation opto-electronic device applications such as solar cells, FETs and flexible detectors etc. In present work, we report growth and characterization of crystalline ternary alloy WSSe by direct vapour transport technique. A photodetector is constructed using grown crystals to study its transient photoresponse under polychromatic radiation. The WSSe crystals are mechanically exfoliated to thickness of 3 µm and the lateral dimension of prepared sample is 2.25 mm2. The time-resolved photoresponse is studied under polychromatic illumination of power density ranging from 10 to 40 mW/cm2. The photo response is also studied under different bias voltages ranging from 0.1 V to 0.5 V. The typical photodetector parameters i.e. photocurrent, rise and fall time, responsivity and sensitivity are evaluated and discussed in light of the ternary alloy composition.

Type III-L Solar Radio Bursts and Solar Energetic Particle Events

Science.gov (United States)

Duffin, R. T.; White, S. M.; Ray, P. S.; Kaiser, M. L.

2015-09-01

A radio-selected sample of fast drift radio bursts with complex structure occurring after the impulsive phase of the associated flare (“Type III-L bursts”) is identified by inspection of radio dynamic spectra from 1 to 180 MHz for over 300 large flares in 2001. An operational definition that takes into account previous work on these radio bursts starting from samples of solar energetic particle (SEP) events is applied to the data, and 66 Type III-L bursts are found in the sample. In order to determine whether the presence of these radio bursts can be used to predict the occurrence of SEP events, we also develop a catalog of all SEP proton events in 2001 using data from the ERNE detector on the SOHO satellite. 68 SEP events are found, for 48 of which we can identify a solar source and hence look for associated Type III-L emission. We confirm previous work that found that most (76% in our sample) of the solar sources of SEP events exhibit radio emission of this type. However, the correlation in the opposite direction is not as strong: starting from a radio-selected sample of Type III-L events, around 64% of the bursts that occur at longitudes magnetically well-connected to the Earth, and hence favorable for detection of SEPs, are associated with SEP events. The degree of association increases when the events have durations over 10 minutes at 1 MHz, but in general Type III-L bursts do not perform any better than Type II bursts in our sample as predictors of SEP events. A comparison of Type III-L timing with the arrival of near-relativistic electrons at the ACE spacecraft is not inconsistent with a common source for the accelerated electrons in both phenomena.

Type III-L Solar Radio Bursts and Solar Energetic Particle Events

International Nuclear Information System (INIS)

Duffin, R T; White, S M; Ray, P S; Kaiser, M L

2015-01-01

A radio-selected sample of fast drift radio bursts with complex structure occurring after the impulsive phase of the associated flare (“Type III-L bursts”) is identified by inspection of radio dynamic spectra from 1 to 180 MHz for over 300 large flares in 2001. An operational definition that takes into account previous work on these radio bursts starting from samples of solar energetic particle (SEP) events is applied to the data, and 66 Type III-L bursts are found in the sample. In order to determine whether the presence of these radio bursts can be used to predict the occurrence of SEP events, we also develop a catalog of all SEP proton events in 2001 using data from the ERNE detector on the SOHO satellite. 68 SEP events are found, for 48 of which we can identify a solar source and hence look for associated Type III-L emission. We confirm previous work that found that most (76% in our sample) of the solar sources of SEP events exhibit radio emission of this type. However, the correlation in the opposite direction is not as strong: starting from a radio-selected sample of Type III-L events, around 64% of the bursts that occur at longitudes magnetically well-connected to the Earth, and hence favorable for detection of SEPs, are associated with SEP events. The degree of association increases when the events have durations over 10 minutes at 1 MHz, but in general Type III-L bursts do not perform any better than Type II bursts in our sample as predictors of SEP events. A comparison of Type III-L timing with the arrival of near-relativistic electrons at the ACE spacecraft is not inconsistent with a common source for the accelerated electrons in both phenomena. (paper)

Protein-mediated efficient synergistic "antenna effect" in a ternary system in D₂O medium.

Science.gov (United States)

Ghorai, Shyamal Kr; Samanta, Swarna Kamal; Mukherjee, Manini; Ghosh, Sanjib

2012-08-16

A ternary system consisting of a protein, catechin (either + or - epimer), and Tb(III) in suitable aqueous buffer medium at physiological pH (= 6.8) has been shown to exhibit highly efficient "antenna effect". Steady state and time-resolved emission studies of each component in the binary complexes (protein with Tb(III) and (+)- or (-)-catechin with Tb(III)) and the ternary systems along with the molecular docking studies reveal that the efficient sensitization could be ascribed to the effective shielding of microenvironment of Tb(III) from O-H oscillator and increased Tb-C (+/-) interaction in the ternary systems in aqueous medium. The ternary system exhibits protein-mediated efficient antenna effect in D(2)O medium due to synergistic ET from both the lowest ππ* triplet state of Trp residue in protein and that of catechin apart from protection of the Tb(III) environment from matrix vibration. The simple system consisting of (+)- or (-)-catechin and Tb(III) in D(2)O buffer at pH 6.8 has been prescribed to be a useful biosensor.

Structural, magnetic and electronic properties of rare earth ternary oxides Li Ln(II) 2 Ln(III)O4

International Nuclear Information System (INIS)

Malki, M.

1987-06-01

Properties of a new class of rare earth ternary oxides Li Ln(II) 2 Ln(III)O 4 where Ln(II) is a divalent metal (Sr, Eu) and Ln(III) a trivalent rare earth (Eu, Gd, Dy, Er and Y). These orthorhombic compounds (type Li Eu 3 O 4 ) allow the study of many magnetic phenomena and their evolution in function of the nature of Ln(II) and Ln(III): diamagnetic ions Sr 2+ , Y 3+ ; isotrope magnetic ions: Eu 2+ , Gd 3+ and anisotrope magnetic ions Dy 3+ , Er 3+ . Magnetic and electric properties are obtained by classical techniques and from hyperfine interaction by Moessbauer spectroscopy. The possibility to use several Moessbauer resonance (nuclei Eu 151, Gd 155, Dy 161 and Er 166) completes informations obtained by the macroscopic study [fr

Ternary semitransparent organic solar cells with a laminated top electrode.

Science.gov (United States)

Makha, Mohammed; Testa, Paolo; Anantharaman, Surendra Babu; Heier, Jakob; Jenatsch, Sandra; Leclaire, Nicolas; Tisserant, Jean-Nicolas; Véron, Anna C; Wang, Lei; Nüesch, Frank; Hany, Roland

2017-01-01

Tinted and colour-neutral semitransparent organic photovoltaic elements are of interest for building-integrated applications in windows, on glass roofs or on facades. We demonstrate a semitransparent organic photovoltaic cell with a dry-laminated top electrode that achieves a uniform average visible transmittance of 51% and a power conversion efficiency of 3%. The photo-active material is based on a majority blend composed of a visibly absorbing donor polymer and a fullerene acceptor, to which a selective near-infrared absorbing cyanine dye is added as a minority component. Our results show that organic ternary blends are attractive for the fabrication of semitransparent solar cells in general, because a guest component with a complementary absorption can compensate for the inevitably reduced current generation capability of a high-performing binary blend when applied as a thin, semitransparent film.

Some new protonated ternary complexes of rare-earths with CDTA/DTPA and keto-glutaric acid

International Nuclear Information System (INIS)

Tripathi, S.P.; Chaturvedi, G.K.; Sharma, R.C.

1981-01-01

Potentiometric evidences have been cited for the formation of 1:1:1, M(III)-CDTA/DTPA-H 2 KGA ternary complexes in the solution equilibria (where M(III)=LA(III), Pr(III), Nd(III), Gd(III) or Dy(III); CDTA=1,2-diaminocyclohexanetetra-acetic acid; DTPA=diethylenetriaminepenta-acetic acid and H 2 KGA= β-ketoglutaric acid). Indications have been cited for the formation of protonated mixed ligand complexes at low pH as intermediate products, which undergo deprotonation at comparatively high pH forming 1:1:1, ternary species. The formation constants (log Ksub(MLL')) for the protonated ternary species, formed by simultaneous addition of both the ligands to metal ion and their deprotonation constants - log Ksub(A)sup(H) have been evaluated. The following order in the relative stabilities of the resulting complexes in terms of metal ions, La(III) < Pr(III) < Nd(III) < Gd(III) < Dy(III), has been observed. (author)

Influence of electron-donating polymer addition on the performance of polymer solar cells

International Nuclear Information System (INIS)

Kim, Youngkyoo; Shin, Minjung; Kim, Hwajeong; Ha, Youri; Ha, Chang-Sik

2008-01-01

Here we report the influence of electron-donating polymer addition on the performance of poly(3-hexylthiophene) (P3HT) : 1-(3-methoxycarbonyl)-propyl-1-phenyl-(6,6)C 61 (PCBM) solar cells. Poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) was chosen as the electron-donating polymer to improve the open circuit voltage (V OC ) due to its higher level of the highest occupied molecular orbital energy compared with P3HT. Results showed that the MDMO-PPV addition led to an improved V OC for ternary blend (P3HT : MDMO-PPV : PCBM) solar cells. In particular, after thermal annealing at 110 deg. C, the short circuit current density of ternary blend solar cells was greatly improved, close to that of comparative binary blend (P3HT : PCBM) solar cells.

III-V semiconductor materials and devices

CERN Document Server

Malik, R J

1989-01-01

The main emphasis of this volume is on III-V semiconductor epitaxial and bulk crystal growth techniques. Chapters are also included on material characterization and ion implantation. In order to put these growth techniques into perspective a thorough review of the physics and technology of III-V devices is presented. This is the first book of its kind to discuss the theory of the various crystal growth techniques in relation to their advantages and limitations for use in III-V semiconductor devices.

Flow injection spectrophotometric determination of Fe(III) and V(v)

International Nuclear Information System (INIS)

Elrahman, Azza Mohamed

2000-01-01

Phenylflourone was synthesized with the objective of developing a method for determining Fe(III) and V(V) in the pressence of micelles using flow injectoin technique. Phenylflourone showed a wavelength of maximum absorption at 412 nm which was not affected by the presence of miccelles i.e. n-hexadodecylpyridinum bromide and sodium n-dodecylsulphate, but they have different effects on the absorbance of PHF. The example of PHF-Fe(III) and PHF-V(V) showed the wavelength of the maximum absorption at 4428 nm and 412 nm, respectively. Presence of micelles shifted the wavelength of the two complexes to a lower one. Generally the addition of micelles increased the absorbance of phenylflourone metal ions complexes except for PHF-V(V) with hexadodecylpyridinum bromide. With flow injection technique two approaches were practiced the use of micelle as a carrier or water as a carrier. Sodium n-dodecylsulphate increased the absorbance of the two complexes when it was used as a carrier or added to the metal ions using water as carrier. On the other hand, the use of n-hexadodecylpyridinum bromide as carrieer increased the absorbance of the complexes but it decreased the absorbance when it was used in conjunction with metal ions and water as a carrier. After establishing the optimum FI conditions for PHF-Fe(III) and PHF-V(V) complexes, the calibration curves were construction and produced semiliner response in the concentration range studied. Ti(IV) III, Mo(VI) showed a positive interference in PHF-Fe(III) and PHF-V(V) complexes, respectively.(Author)

One-pot synthesis of ternary zero-valent iron/phosphotungstic acid/g-C3N4 composite and its high performance for removal of arsenic(V) from water

Science.gov (United States)

Chen, Chunhua; Xu, Jia; Yang, Zhihua; Zhang, Li; Cao, Chunhua; Xu, Zhihua; Liu, Jiyan

2017-12-01

Ternary zero-valent iron/phos photungstic acid/g-C3N4 composite (Fe0@PTA/g-C3N4) was synthesized via photoreduction of iron (II) ions assisted by phosphotungstic acid (PTA) over g-C3N4 flakes. The as-prepared Fe0@PTA/g-C3N4 was investigated for removal of As(III) and As(V) species from water. The result showed that Fe0@PTA/g-C3N4 exhibited a better performance for As(V) removal than As(III) species from water, and the maximum adsorption capacity for As(V) was 70.3 mg/g, much higher than most of the reported adsorbents. As(V) removal by the Fe0@PTA/g-C3N4 adsorbent is mainly via a chemical process, synergistically occurring of reduction of As(V) and oxidation of Fe0. Moreover, the Fe0@PTA/g-C3N4 adsorbent showed effective As(V) removal from the simulated industrial wastewater and underground water. This study demonstrates that Fe0@PTA/g-C3N4 can be a potential adsorbent for As(V) removal due to its high performance, and simple one-pot synthesis process.

Efficient Approach for Improving the Performance of Nonhalogenated Green Solvent-Processed Polymer Solar Cells via Ternary-Blend Strategy.

Science.gov (United States)

Kranthiraja, Kakaraparthi; Aryal, Um Kanta; Sree, Vijaya Gopalan; Gunasekar, Kumarasamy; Lee, Changyeon; Kim, Minseok; Kim, Bumjoon J; Song, Myungkwan; Jin, Sung-Ho

2018-04-10

The ternary-blend approach has the potential to enhance the power conversion efficiencies (PCEs) of polymer solar cells (PSCs) by providing complementary absorption and efficient charge generation. Unfortunately, most PSCs are processed with toxic halogenated solvents, which are harmful to human health and the environment. Herein, we report the addition of a nonfullerene electron acceptor 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3- d:2',3'- d']- s-indaceno[1,2- b:5,6- b']dithiophene (ITIC) to a binary blend (poly[4,8-bis(2-(4-(2-ethylhexyloxy)3-fluorophenyl)-5-thienyl)benzo[1,2- b:4,5- b']dithiophene- alt-1,3-bis(4-octylthien-2-yl)-5-(2-ethylhexyl)thieno[3,4- c]pyrrole-4,6-dione] (P1):[6,6]-phenyl-C 71 -butyric acid methyl ester (PC 71 BM), PCE = 8.07%) to produce an efficient nonhalogenated green solvent-processed ternary PSC system with a high PCE of 10.11%. The estimated wetting coefficient value (0.086) for the ternary blend suggests that ITIC could be located at the P1:PC 71 BM interface, resulting in efficient charge generation and charge transport. In addition, the improved current density, sustained open-circuit voltage and PCE of the optimized ternary PSCs were highly correlated with their better external quantum efficiency response and flat-band potential value obtained from the Mott-Schottky analysis. In addition, the ternary PSCs also showed excellent ambient stability over 720 h. Therefore, our results demonstrate the combination of fullerene and nonfullerene acceptors in ternary blend as an efficient approach to improve the performance of eco-friendly solvent-processed PSCs with long-term stability.

Antisites in III-V semiconductors: Density functional theory calculations

KAUST Repository

Chroneos, A.

2014-07-14

Density functional based simulation, corrected for finite size effects, is used to investigate systematically the formation of antisite defects in III-V semiconductors (III=Al, Ga, and In and V=P, As, and Sb). Different charge states are modelled as a function of the Fermi level and under different growth conditions. The formation energies of group III antisites (III V q) decrease with increasing covalent radius of the group V atom though not group III radius, whereas group V antisites (V I I I q) show a consistent decrease in formation energies with increase in group III and group V covalent radii. In general, III V q defects dominate under III-rich conditions and V I I I q under V-rich conditions. Comparison with equivalent vacancy formation energy simulations shows that while antisite concentrations are always dominant under stoichiometric conditions, modest variation in growth or doping conditions can lead to a significantly higher concentration of vacancies. © 2014 AIP Publishing LLC.

In situ spectroscopic evidence for neptunium(V)-carbonate inner-sphere and outer-sphere ternary surface complexes on hematite surfaces.

Science.gov (United States)

Arai, Yuji; Moran, P B; Honeyman, B D; Davis, J A

2007-06-01

Np(V) surface speciation on hematite surfaces at pH 7-9 under pC2 = 10(-3.45) atm was investigated using X-ray absorption spectroscopy (XAS). In situ XAS analyses suggest that bis-carbonato inner-sphere and tris-carbonato outer-sphere ternary surface species coexist at the hematite-water interface at pH 7-8.8, and the fraction of outer-sphere species gradually increases from 27 to 54% with increasing pH from 7 to 8.8. The results suggest that the heretofore unknown Np(V)-carbonato ternary surface species may be important in predicting the fate and transport of Np(V) in the subsurface environment down gradient of high-level nuclear waste respositories.

The A1 to L10 transformation in FePt films with ternary alloying additions of Mg, V, Mn, and B

International Nuclear Information System (INIS)

Wang, B.; Barmak, K.; Klemmer, T. J.

2011-01-01

The impact of ternary additions of Mg, V, Mn, and B on the A1 [face centered cubic (fcc)] to L1 0 phase transformation has been studied. The films were cosputter deposited from elemental targets at room temperature and annealed after deposition. The films had Mg additions in the range ∼0-2.6 at.%, V additions in the range 0.7-12.2 at.%, Mn additions in the range 2.2-16.3 at.%, and B additions in the range 1.2-12.9 at.%. For all four ternary alloy systems, annealing resulted in the formation of no other phases than the L1 0 phase. Ternary additions of C than the binary FePt films with the same Pt content.

Technological development for super-high efficiency solar cells. Technological development for crystalline compound solar cells (high-efficiency III-V tandem solar cells); Chokokoritsu taiyo denchi no gijutsu kaihatsu. Kessho kagobutsu taiyo denchi no gijutsu kaihatsu (III-V zoku kagobutsu handotai taiyo denchi no gijutsu kaihatsu)

Energy Technology Data Exchange (ETDEWEB)

Tatsuta, M [New Energy and Industrial Technology Development Organization, Tokyo (Japan)

1994-12-01

This paper reports the study results on technological development of III-V compound semiconductor solar cells in fiscal 1994. (1) On development of epitaxial growth technology of lattice mismatching systems, the optimum structure of InGaAs strain intermediate layers was studied for reducing a dislocation density by lattice mismatching of GaAs layer grown on Si substrate and difference in thermal expansion coefficient. The effect of strain layer on dislocation reduction was found only at 250dyne/cm in strain energy. Growth of GaAs layers on the Si substrate treated by hydrofluoric acid at low temperature was attempted by MBE method. As a dislocation distribution was controlled by laying different atoms at hetero-interface, the dislocation density of growing layer surfaces decreased by concentration of dislocation at hetero-interface. (2) On development of high-efficiency tandem cell structure, tunnel junction characteristics, cell formation process and optimum design method of lattice matching tandem cells were studied, while thin film cell formation was basically studied for lattice mismatching tandem cells. 45 figs., 8 tabs.

Ternary System with Controlled Structure: A New Strategy toward Efficient Organic Photovoltaics.

Science.gov (United States)

Cheng, Pei; Wang, Rui; Zhu, Jingshuai; Huang, Wenchao; Chang, Sheng-Yung; Meng, Lei; Sun, Pengyu; Cheng, Hao-Wen; Qin, Meng; Zhu, Chenhui; Zhan, Xiaowei; Yang, Yang

2018-02-01

Recently, a new type of active layer with a ternary system has been developed to further enhance the performance of binary system organic photovoltaics (OPV). In the ternary OPV, almost all active layers are formed by simple ternary blend in solution, which eventually leads to the disordered bulk heterojunction (BHJ) structure after a spin-coating process. There are two main restrictions in this disordered BHJ structure to obtain higher performance OPV. One is the isolated second donor or acceptor domains. The other is the invalid metal-semiconductor contact. Herein, the concept and design of donor/acceptor/acceptor ternary OPV with more controlled structure (C-ternary) is reported. The C-ternary OPV is fabricated by a sequential solution process, in which the second acceptor and donor/acceptor binary blend are sequentially spin-coated. After the device optimization, the power conversion efficiencies (PCEs) of all OPV with C-ternary are enhanced by 14-21% relative to those with the simple ternary blend; the best PCEs are 10.7 and 11.0% for fullerene-based and fullerene-free solar cells, respectively. Moreover, the averaged PCE value of 10.4% for fullerene-free solar cell measured in this study is in great agreement with the certified one of 10.32% obtained from Newport Corporation. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Reducing the efficiency–stability–cost gap of organic photovoltaics with highly efficient and stable small molecule acceptor ternary solar cells

KAUST Repository

Baran, Derya

2016-11-21

Technological deployment of organic photovoltaic modules requires improvements in device light-conversion efficiency and stability while keeping material costs low. Here we demonstrate highly efficient and stable solar cells using a ternary approach, wherein two non-fullerene acceptors are combined with both a scalable and affordable donor polymer, poly(3-hexylthiophene) (P3HT), and a high-efficiency, low-bandgap polymer in a single-layer bulk-heterojunction device. The addition of a strongly absorbing small molecule acceptor into a P3HT-based non-fullerene blend increases the device efficiency up to 7.7 ± 0.1% without any solvent additives. The improvement is assigned to changes in microstructure that reduce charge recombination and increase the photovoltage, and to improved light harvesting across the visible region. The stability of P3HT-based devices in ambient conditions is also significantly improved relative to polymer:fullerene devices. Combined with a low-bandgap donor polymer (PBDTTT-EFT, also known as PCE10), the two mixed acceptors also lead to solar cells with 11.0 ± 0.4% efficiency and a high open-circuit voltage of 1.03 ± 0.01 V.

Reducing the efficiency–stability–cost gap of organic photovoltaics with highly efficient and stable small molecule acceptor ternary solar cells

KAUST Repository

Baran, Derya; Ashraf, Raja; Hanifi, David A.; Abdelsamie, Maged; Gasparini, Nicola; Rö hr, Jason A.; Holliday, Sarah; Wadsworth, Andrew; Lockett, Sarah; Neophytou, Marios; Emmott, Christopher J. M.; Nelson, Jenny; Brabec, Christoph J.; Amassian, Aram; Salleo, Alberto; Kirchartz, Thomas; Durrant, James R.; McCulloch, Iain

2016-01-01

Technological deployment of organic photovoltaic modules requires improvements in device light-conversion efficiency and stability while keeping material costs low. Here we demonstrate highly efficient and stable solar cells using a ternary approach, wherein two non-fullerene acceptors are combined with both a scalable and affordable donor polymer, poly(3-hexylthiophene) (P3HT), and a high-efficiency, low-bandgap polymer in a single-layer bulk-heterojunction device. The addition of a strongly absorbing small molecule acceptor into a P3HT-based non-fullerene blend increases the device efficiency up to 7.7 ± 0.1% without any solvent additives. The improvement is assigned to changes in microstructure that reduce charge recombination and increase the photovoltage, and to improved light harvesting across the visible region. The stability of P3HT-based devices in ambient conditions is also significantly improved relative to polymer:fullerene devices. Combined with a low-bandgap donor polymer (PBDTTT-EFT, also known as PCE10), the two mixed acceptors also lead to solar cells with 11.0 ± 0.4% efficiency and a high open-circuit voltage of 1.03 ± 0.01 V.

Synthesis, characteristics and luminescent properties of a new Tb(III) ternary complex applied in near UV-based LED

Science.gov (United States)

Sun, Naiqun; Li, Liping; Yang, Yamin; Zhang, Aiqin; Jia, Husheng; Liu, Xuguang; Xu, Bingshe

2015-11-01

A novel Tb(III) ternary complex, Tb(p-BBA)3UA, was synthesized with 4-benzoylbenzoic acid (p-BBA) as primary ligand and undecylenic acid (UA) as reactive ligand. Tb(III) complex exhibits high thermal stability and wide and strong excitation bands from 310 nm to 400 nm when monitored at 543 nm, which matches well with the 365 nm UV chip. The complex displays Tb(III) characteristic peaks at 488, 543, 584 and 619 nm under the excitation of 365 nm UV-light. The intramolecular energy transfer process was also discussed. Meanwhile, the complex has longer fluorescence lifetime (1.317 ms) and higher quantum yield (44.8%). When used in LED with 365 nm UV chip (power efficiency is 17.3 lm/W), the complex still maintained its qualified luminescent performance. All the results indicate that Tb(p-BBA)3UA can be applied as a green component for fabrication of near UV-based white LED.

Antisites in III-V semiconductors: Density functional theory calculations

KAUST Repository

Chroneos, A.; Tahini, Hassan Ali; Schwingenschlö gl, Udo; Grimes, R. W.

2014-01-01

as a function of the Fermi level and under different growth conditions. The formation energies of group III antisites (III V q) decrease with increasing covalent radius of the group V atom though not group III radius, whereas group V antisites (V I I I

C-V Calculations in CdS/CdTe Thin Films Solar Cells with a CdSxTe1-x Interlayer

Directory of Open Access Journals (Sweden)

A. Gonzalez-Cisneros

2013-01-01

Full Text Available In CdS/CdTe solar cells, chemical interdiffusion at the interface gives rise to the formation of an interlayer of the ternary compound CdSxCdTe1-x. In this work, we evaluate the effects of this interlayer in CdS/CdTe photovoltaic cells in order to improve theoretical results describing experimental C-V (capacitance versus voltage characteristics. We extended our previous theoretical methodology developed on the basis of three cardinal equations (Castillo-Alvarado et al., 2010. The present results provide a better fit to experimental data obtained from CdS/CdTe solar cells grown in our laboratory by the chemical bath deposition (for CdS film and the close-spaced vapor transport (for CdTe film techniques.

Theoretical prediction and experimental confirmation of unusual ternary ordered semiconductor compounds in Sr-Pb-S system.

Science.gov (United States)

Hao, Shiqiang; Zhao, Li-Dong; Chen, Chang-Qiang; Dravid, Vinayak P; Kanatzidis, Mercouri G; Wolverton, Christopher M

2014-01-29

We examine the thermodynamics of phase separation and ordering in the ternary Ca(x)Pb(1-x)S and Sr(x)Pb(1-x)S systems by density-functional theory combined with a cluster expansion and Monte Carlo simulations. Similar to most other ternary III-V or IV-VI semiconductor alloys, we find that bulk phase separation is thermodynamically preferred for PbS-CaS. However, we predict the surprising existence of stable, ordered ternary compounds in the PbS-SrS system. These phases are previously unreported ordered rocksalt-based compounds: SrPb3S4, SrPbS2, and Sr3PbS4. The stability of these predicted ordered phases is confirmed by transmission electron microscopy observations and band gap measurements. We believe this work paves the way for a combined theory-experiment approach to decipher complex phase relations in multicomponent chalcogenide systems.

Multicolor (UV-IR) Photodetectors Based on Lattice-Matched 6.1 A II/VI and III/V Semiconductors

Science.gov (United States)

2015-08-27

copyright information. 13. SUPPLEMENTARY NOTES. Enter information not included elsewhere such as: prepared in cooperation with; translation of; report...II-VI heterojunctions such as multi-color photodetectors and solar cells [2]. Mixing lattice-matched II-VI and III-V semiconductors could be an...at 77 K, further silicon oxide surface passivation can be done to suppress the surface leakage [10] in the future work. Figure 10 The dark I-V

Transformational III-V Electronics

KAUST Repository

Nour, Maha A.

2014-01-01

Flexible electronics using III-V materials for nano-electronics with high electron mobility and optoelectronics with direct band gap are attractive for many applications. This thesis describes a complementary metal oxide semiconductor (CMOS

Peculiarities of component interaction in {Gd, Er}-V-Sn Ternary systems at 870 K and crystal structure of RV6Sn6 stannides

International Nuclear Information System (INIS)

Romaka, L.; Stadnyk, Yu.; Romaka, V.V.; Demchenko, P.; Stadnyshyn, M.; Konyk, M.

2011-01-01

Highlights: → {Gd, Er}-V-Sn ternary systems at 870 K are characterized by formation of stannides with general compositions RV 6 Sn 6 . → Isostructural RV 6 Sn 6 compounds were also found with Y, Dy, Ho, Tm, and Lu. → The crystal structure of RV 6 Sn 6 compounds was determined by powder diffraction method. → Structural analysis showed that RV 6 Sn 6 compounds (R = Gd, Dy-Tm, Lu) are disordered; YV 6 Sn 6 is characterized by structure ordering. - Abstract: The phase equilibria in the Gd-V-Sn and Er-V-Sn ternary systems were studied at 870 K by means of X-ray and metallographic analyses in the whole concentration range. Both Gd-V-Sn and Er-V-Sn systems are characterized by formation of one ternary compound at investigated temperature, with stoichiometry RV 6 Sn 6 (SmMn 6 Sn 6 -type, space group P6/mmm, a = 0.55322(3) nm, c = 0.91949(7) nm for Gd, a = 0.55191(2) nm, c = 0.91869(8) nm for Er). Solubility of the third component in the binary compounds was not observed. Compounds with the SmMn 6 Sn 6 -type were also found with Dy, Ho, Tm, and Lu, while YV 6 Sn 6 compound crystallizes in HfFe 6 Ge 6 structure type. All investigated compounds are the first ternary stannides with rare earth elements and vanadium.

Advances in High-Efficiency III-V Multijunction Solar Cells

Directory of Open Access Journals (Sweden)

Richard R. King

2007-01-01

Full Text Available The high efficiency of multijunction concentrator cells has the potential to revolutionize the cost structure of photovoltaic electricity generation. Advances in the design of metamorphic subcells to reduce carrier recombination and increase voltage, wide-band-gap tunnel junctions capable of operating at high concentration, metamorphic buffers to transition from the substrate lattice constant to that of the epitaxial subcells, concentrator cell AR coating and grid design, and integration into 3-junction cells with current-matched subcells under the terrestrial spectrum have resulted in new heights in solar cell performance. A metamorphic Ga0.44In0.56P/Ga0.92In0.08As/ Ge 3-junction solar cell from this research has reached a record 40.7% efficiency at 240 suns, under the standard reporting spectrum for terrestrial concentrator cells (AM1.5 direct, low-AOD, 24.0 W/cm2, 25∘C, and experimental lattice-matched 3-junction cells have now also achieved over 40% efficiency, with 40.1% measured at 135 suns. This metamorphic 3-junction device is the first solar cell to reach over 40% in efficiency, and has the highest solar conversion efficiency for any type of photovoltaic cell developed to date. Solar cells with more junctions offer the potential for still higher efficiencies to be reached. Four-junction cells limited by radiative recombination can reach over 58% in principle, and practical 4-junction cell efficiencies over 46% are possible with the right combination of band gaps, taking into account series resistance and gridline shadowing. Many of the optimum band gaps for maximum energy conversion can be accessed with metamorphic semiconductor materials. The lower current in cells with 4 or more junctions, resulting in lower I2R resistive power loss, is a particularly significant advantage in concentrator PV systems. Prototype 4-junction terrestrial concentrator cells have been grown by metal-organic vapor-phase epitaxy, with preliminary measured

Photocatalytic activity of attapulgite-TiO2-Ag3PO4 ternary nanocomposite for degradation of Rhodamine B under simulated solar irradiation

Science.gov (United States)

He, Hongcai; Jiang, Zhuolin; He, Zhaoling; Liu, Tao; Li, Enzhu; Li, Bao-Wen

2018-01-01

An excellent ternary composite photocatalyst consisting of silver orthophosphate (Ag3PO4), attapulgite (ATP), and TiO2 was synthesized, in which heterojunction was formed between dissimilar semiconductors to promote the separation of photo-generated charges. The ATP/TiO2/Ag3PO4 composite was characterized by SEM, XRD, and UV-vis diffuse reflectance spectroscopy. The co-deposition of Ag3PO4 and TiO2 nanoparticles onto the surface of ATP forms a lath-particle structure. Compared with composite photocatalysts consisting of two phases, ATP/TiO2/Ag3PO4 ternary composite exhibits greatly improved photocatalytic activity for degradation of rhodamine B under simulated solar irradiation. Such ternary composite not only improves the stability of Ag3PO4, but also lowers the cost by reducing application amount of Ag3PO4, which provides guidance for the design of Ag3PO4- and Ag-based composites for photocatalytic applications.

Improving the performance of solution-processed organic solar cells by incorporating small molecule acceptors into a ternary bulk heterojunction based on DH6T:Mq3:PCBM (M = Ga, Al)

Energy Technology Data Exchange (ETDEWEB)

Muhammad, Fahmi F. [Center for Composites, Institute for Vehicle Systems & Engineering, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Soft Materials & Devices Lab, Department of Physics, Faculty of Science & Health, Koya University, Koya, Kurdistan Region (Iraq); Development Center for Research and Training, University of Human Development, Sulaimani, Kurdistan Region (Iraq); Yahya, Mohd Yazid, E-mail: yazidyahya@utm.my [Center for Composites, Institute for Vehicle Systems & Engineering, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Sulaiman, Khaulah [Low Dimensional Materials Research Centre, Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia)

2017-02-15

Improvement in the overall performance of solution-processed organic solar cells based on a ternary heterostructure was realized by means of incorporating small molecules of tris(8-hydroxyquinoline) gallium (Gaq3) or Alq3 electron acceptors. The donor host polymer was α,ω-dihexyl-sexithiophene (DH6T), while the ultimate acceptor was fullerene (PC{sub 61}BM). The results showed that short circuit current (I{sub Sc}), open circuit voltage (V{sub oc}), and fill factor (FF) of the devices were pronouncedly enhanced by the inclusion of Gaq3 or Alq3. The maximum output power and conversion efficiency of the ternary devices were increased by an order of 5.8 times compared to that of the control devices. These improvements were ascribed to the broadened light absorption, energy levels alignment between the donor-acceptor components, a balanced charge transfer, and increased crystallinity of the devices active layer. The results were ascertained and analyzed by means of UV–Vis, PL, XRD, IV and TEM investigations. - Highlights: • Ternary solution-processed OSCs including Gaq3 and Alq3 acceptors were realized. • The power and efficiency of the devices were increased by an order of 5.8. • Broadened absorption and improved crystallinity were achieved for the active layers.

Improving the performance of solution-processed organic solar cells by incorporating small molecule acceptors into a ternary bulk heterojunction based on DH6T:Mq3:PCBM (M = Ga, Al)

International Nuclear Information System (INIS)

Muhammad, Fahmi F.; Yahya, Mohd Yazid; Sulaiman, Khaulah

2017-01-01

Improvement in the overall performance of solution-processed organic solar cells based on a ternary heterostructure was realized by means of incorporating small molecules of tris(8-hydroxyquinoline) gallium (Gaq3) or Alq3 electron acceptors. The donor host polymer was α,ω-dihexyl-sexithiophene (DH6T), while the ultimate acceptor was fullerene (PC 61 BM). The results showed that short circuit current (I Sc ), open circuit voltage (V oc ), and fill factor (FF) of the devices were pronouncedly enhanced by the inclusion of Gaq3 or Alq3. The maximum output power and conversion efficiency of the ternary devices were increased by an order of 5.8 times compared to that of the control devices. These improvements were ascribed to the broadened light absorption, energy levels alignment between the donor-acceptor components, a balanced charge transfer, and increased crystallinity of the devices active layer. The results were ascertained and analyzed by means of UV–Vis, PL, XRD, IV and TEM investigations. - Highlights: • Ternary solution-processed OSCs including Gaq3 and Alq3 acceptors were realized. • The power and efficiency of the devices were increased by an order of 5.8. • Broadened absorption and improved crystallinity were achieved for the active layers.

GaAsPN-based PIN solar cells MBE-grown on GaP substrates: toward the III-V/Si tandem solar cell

Science.gov (United States)

Da Silva, M.; Almosni, S.; Cornet, C.; Létoublon, A.; Levallois, C.; Rale, P.; Lombez, L.; Guillemoles, J.-F.; Durand, O.

2015-03-01

GaAsPN semiconductors are promising material for the elaboration of high efficiencies tandem solar cells on silicon substrates. GaAsPN diluted nitride alloy is studied as the top junction material due to its perfect lattice matching with the Si substrate and its ideal bandgap energy allowing a perfect current matching with the Si bottom cell. We review our recent progress in materials development of the GaAsPN alloy and our recent studies of some of the different building blocks toward the elaboration of a PIN solar cell. A lattice matched (with a GaP(001) substrate, as a first step toward the elaboration on a Si substrate) 1μm-thick GaAsPN alloy has been grown by MBE. After a post-growth annealing step, this alloy displays a strong absorption around 1.8-1.9 eV, and efficient photoluminescence at room temperature suitable for the elaboration of the targeted solar cell top junction. Early stage GaAsPN PIN solar cells prototypes have been grown on GaP (001) substrates, with 2 different absorber thicknesses (1μm and 0.3μm). The external quantum efficiencies and the I-V curves show that carriers have been extracted from the GaAsPN alloy absorbers, with an open-circuit voltage of 1.18 V, while displaying low short circuit currents meaning that the GaAsPN structural properties needs a further optimization. A better carrier extraction has been observed with the absorber displaying the smallest thickness, which is coherent with a low carriers diffusion length in our GaAsPN compound. Considering all the pathways for improvement, the efficiency obtained under AM1.5G is however promising.

New III-V cell design approaches for very high efficiency

Energy Technology Data Exchange (ETDEWEB)

Lundstrom, M.S.; Melloch, M.R.; Lush, G.B.; Patkar, M.P.; Young, M.P. (Purdue Univ., Lafayette, IN (United States))

1993-04-01

This report describes to examine new solar cell desip approaches for achieving very high conversion efficiencies. The program consists of two elements. The first centers on exploring new thin-film approaches specifically designed for M-III semiconductors. Substantial efficiency gains may be possible by employing light trapping techniques to confine the incident photons, as well as the photons emitted by radiative recombination. The thin-film approach is a promising route for achieving substantial performance improvements in the already high-efficiency, single-junction, III-V cell. The second element of the research involves exploring desip approaches for achieving high conversion efficiencies without requiring extremely high-quality material. This work has applications to multiple-junction cells, for which the selection of a component cell often involves a compromise between optimum band pp and optimum material quality. It could also be a benefit manufacturing environment by making the cell's efficiency less dependent on materialquality.

Desarrollo de la tecnología de MOVPE para el crecimiento de semiconductores III-V : fabricación de células solares para concentraciones luminosas elevadas

OpenAIRE

Galiana Blanco, Beatriz

2011-01-01

El trabajo de estas tesis trata sobre el desarrollo en el IES-UPM de la tecnología de crecimiento epitaxial de fase vapor mediante precursores metalorgánicos (MOVPE) para el crecimiento de células solares de semiconductores III-V para concentraciones luminosas elevadas. En la primera parte de la memoria se presentan los principios de la MOVPE y el estudio de los materiales semiconductores utilizados a lo largo de la tesis: GaAs, AlGaAs, GaInP y AlInP. Para ello, se ha analizado cómo influ...

Magnetooptical investigations on ferromagnetic III-V-semiconductors; Magnetooptische Untersuchungen an ferromagnetischen III-V-Halbleitern

Energy Technology Data Exchange (ETDEWEB)

Winter, Andreas

2009-07-23

Magnetooptical Kerr effect (MOKE) and Magnetic Circular Dichroism (MCD) have been used to investigate magnetic as well as bandstructure properties of diluted magnetic III-V-semiconductors containing Mn. In these ferromagnetic systems it has been found that the strength of the observed effects depends linearly on the magnetization of the samples with no influence of the external magnetic field. The magnetooptical effects allowed the recording of hysteresis loops of GaMnAs, GaMnSb, InMnAs and InMnSb samples for different temperatures and in the case of GaMnAs also for different alignments of the external magnetic field with respect to the easy axis of magnetization. The Stoner-Wohlfahrt-Model has been used to describe the resulting shapes of the loops yielding the magnetic anisotropy parameters of the samples. For magnetically saturated samples, spectra of MOKE and MCD have been recorded. Contrary to pure III-V-semiconductors, which exhibit lots of sharp resonances due to interband transitions between Landau levels, III-Mn-V-semi-conductors how only very few (or just one) considerably broad resonance(s). Their spectral position(s) do(es) neither depend upon the magnetic field as it would be the case for pure III-V-semiconductors nor the magnetization. Only the amplitude increases linearly with the magnetization. Utilizing a kp-theory it has been possible to describe the observed dependencies. Valence- and conduction-band are split into Landau levels by the external magnetic field and, in addition to the Zeeman-effect, the spin-levels are split by the exchange interaction between the localized electrons of the Mn ions and the free carriers which is proportional to the magnetization of the samples. This splitting is much bigger than the Landau level splitting. Due to an inhomogeneous distribution of the Mn ions and due to the high carrier density the Landau levels are strongly broadened and their structure is not observable. Owing to the high carrier-concentration in

Ternary fission of 184466,476X formed in U + U collisions

International Nuclear Information System (INIS)

Karthikraj, C.; Subramanian, S.; Selvaraj, S.

2016-01-01

Recently, the very rare process of nuclear ternary fission has been of great interest in nuclear dynamics. Based on the statistical theory of fission, we discuss here the ternary-fission mass distribution of 184 466,476 X formed in low-energy U + U collisions for different heavy third fragments at T = 1 and 2 MeV. The expected ternary configurations 208 Pb + 208 Pb + 50 Ca and 204 Hg + 204 Hg + 58 Cr are obtained from the ternary fission of 184 466 X at T = 2 MeV. In addition, for both the systems, various possible ternary modes are listed for different heavy third fragments. Our results clearly indicate that the favored ternary configurations have either proton and/or neutron shell closure nucleus as one of their partners. (orig.)

Removal of arsenic from water using manganese (III) oxide: Adsorption of As(III) and As(V).

Science.gov (United States)

Babaeivelni, Kamel; Khodadoust, Amid P

2016-01-01

Removal of arsenic from water was evaluated with manganese (III) oxide (Mn2O3) as adsorbent. Adsorption of As(III) and As(V) onto Mn2O3 was favorable according to the Langmuir and Freundlich adsorption equilibrium equations, while chemisorption of arsenic occurred according to the Dubinin-Radushkevich equation. Adsorption parameters from the Langmuir, Freundlich, and Temkin equations showed a greater adsorption and removal of As(III) than As(V) by Mn2O3. Maximum removal of As(III) and As(V) occurred at pH 3-9 and at pH 2, respectively, while removal of As(V) in the pH range of 6-9 was 93% (pH 6) to 61% (pH 9) of the maximum removal. Zeta potential measurements for Mn2O3 in As(III) was likely converted to As(V) solutions indicated that As(III) was likely converted to As(V) on the Mn2O3 surface at pH 3-9. Overall, the effective Mn2O3 sorbent rapidly removed As(III) and As(V) from water in the pH range of 6-9 for natural waters.

Position-controlled epitaxial III-V nanowires on silicon

Energy Technology Data Exchange (ETDEWEB)

Roest, Aarnoud L; Verheijen, Marcel A; Wunnicke, Olaf; Serafin, Stacey; Wondergem, Harry; Bakkers, Erik P A M [Philips Research Laboratories, Professor Holstlaan 4, 5656 AA Eindhoven (Netherlands); Kavli Institute of NanoScience, Delft University of Technology, PO Box 5046, 2600 GA Delft (Netherlands)

2006-06-14

We show the epitaxial integration of III-V semiconductor nanowires with silicon technology. The wires are grown by the VLS mechanism with laser ablation as well as metal-organic vapour phase epitaxy. The hetero-epitaxial growth of the III-V nanowires on silicon was confirmed with x-ray diffraction pole figures and cross-sectional transmission electron microscopy. We show preliminary results of two-terminal electrical measurements of III-V nanowires grown on silicon. E-beam lithography was used to predefine the position of the nanowires.

Position-controlled epitaxial III-V nanowires on silicon

International Nuclear Information System (INIS)

Roest, Aarnoud L; Verheijen, Marcel A; Wunnicke, Olaf; Serafin, Stacey; Wondergem, Harry; Bakkers, Erik P A M

2006-01-01

We show the epitaxial integration of III-V semiconductor nanowires with silicon technology. The wires are grown by the VLS mechanism with laser ablation as well as metal-organic vapour phase epitaxy. The hetero-epitaxial growth of the III-V nanowires on silicon was confirmed with x-ray diffraction pole figures and cross-sectional transmission electron microscopy. We show preliminary results of two-terminal electrical measurements of III-V nanowires grown on silicon. E-beam lithography was used to predefine the position of the nanowires

Energy dissipation in the process of ternary fission in heavy nuclear reaction

International Nuclear Information System (INIS)

Li Xian; Wang Chengqian; Yan Shiwei

2015-01-01

We studied the evolution of the collective motion, interaction potential, the total kinetic and excitation energies in ternary fissions of 197 Au + 197 Au system at 15 MeV/u, and discussed energy dissipation of this reaction. Through the comparison with energy-angle correlation data in binary fissions, we preliminarily concluded that the rst fission of ternary fission was an extreme deep-inelastic process. We further analyzed the correlation of the total kinetic energy with impact parameters in both binary and ternary reactions, and found that the total energy of binary reactions systems was lost about 150 MeV more than ternary fission with small impact parameters, and with larger impact parameters the total energy of ternary reactions were lost 300 MeV more than binary reactions. (authors)

A comparative study of three ternary complexes prepared in different mixing orders of siRNA/redox-responsive hyperbranched poly (amido amine/hyaluronic acid

Directory of Open Access Journals (Sweden)

Chen CJ

2012-07-01

Full Text Available Cheng-Jun Chen,1 Zhi-Xia Zhao,1 Jian-Cheng Wang,1 En-Yu Zhao,1 Ling-Yan Gao,1 Shu-Feng Zhou,2 Xiao-Yan Liu,1 Wan-Liang Lu,1 Qiang Zhang11State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmaceutics, School of Pharmaceutical Science, Peking University, Beijing, People’s Republic of China; 2Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USAAbstract: In this study, a novel redox-responsive hyperbranched poly(amido amine (named PCD was synthesized and used as a cationic polymer to form a ternary complex with small interfering RNA (siRNA and hyaluronic acid (HA for siRNA delivery. Here, it is hypothesized that different mixing orders result in different assembly structures, which may affect the siRNA delivery efficiency. To investigate the effects of mixing orders on siRNA delivery efficiency in two human breast cancer cell lines, three ternary complexes with different mixing orders of siRNA/PCD/HA were prepared and characterized: mixing order I (initially prepared siRNA/PCD binary complex further coated by negatively charged HA, mixing order II (initially prepared HA/PCD binary complex further incubated with siRNA, and mixing order III (initially prepared siRNA/HA mixture further electrostatically compacted by positively charged PCD. With an optimized siRNA/PCD/HA charge ratio of 1/20/16, the particle sizes and zeta potentials of these ternary complexes were 124.8 nm and 27.3 mV (mixing order I, 147.5 nm and 29.9 mV (mixing order II, and 128.8 nm and 19.4 mV (mixing order III. Also, the effects on stability, cellular uptake, and gene silencing efficiency of siRNA formulated in ternary complexes with different mixing orders were investigated. The results showed that mixing orders I and III displayed better siRNA transfection and protection than mixing order II in human breast cancer MCF-7 and MDA-MB-231 cells. More interesting, at the siRNA/PCD/HA charge ratio of 1/20/16, the

Stimulation of auroral kilometric radiation by type III solar radio bursts

International Nuclear Information System (INIS)

Calvert, W.

1981-01-01

It has been found that the onset of auroral kilometric radiation (AKR) frequently coincides with the arrival of type III solar radio bursts. Although the AKR onsets are usually abrupt and appear to be spontaneous, they sometimes develop from a discrete frequency near the leading edge of a type III burst or sometimes occur at progressively lower frequencies following that edge. From this, and the absence of the related solar electrons in specific cases, it was concluded that the incoming type III waves were sometimes responsible for stimulating auroral kilometric radiation. It was estimated that intense, isolated type III bursts were capable of stimulating AKR roughly one third of the time, and that at least ten percent of the observed AKR onsets could be attributed to these and weaker bursts, including some barely detectable by the ISEE plasma wave receivers

Transformational III-V Electronics

KAUST Repository

Nour, Maha A.

2014-04-01

Flexible electronics using III-V materials for nano-electronics with high electron mobility and optoelectronics with direct band gap are attractive for many applications. This thesis describes a complementary metal oxide semiconductor (CMOS) compatible process for transforming traditional III-V materials based electronics into flexible one. The thesis reports releasing 200 nm of Gallium Arsenide (GaAs) from 200 nm GaAs / 300 nm Aluminum Arsenide (AlAs) stack on GaAs substrate using diluted hydrofluoric acid (HF). This process enables releasing a single top layer compared to peeling off all layers with small sizes at the same time. This is done utilizing a network of release holes that contributes to the better transparency (45 % at 724 nm wavelengths) observed. Fabrication of metal oxide semiconductor capacitor (MOSCAPs) on GaAs is followed by releasing it to have devices on flexible 200 nm GaAs. Similarly, flexible GaSb and InP fabrication process is also reported to transform traditional electronics into large-area flexible electronics.

Interplanetary Type III Bursts and Electron Density Fluctuations in the Solar Wind

Science.gov (United States)

Krupar, V.; Maksimovic, M.; Kontar, E. P.; Zaslavsky, A.; Santolik, O.; Soucek, J.; Kruparova, O.; Eastwood, J. P.; Szabo, A.

2018-04-01

Type III bursts are generated by fast electron beams originated from magnetic reconnection sites of solar flares. As propagation of radio waves in the interplanetary medium is strongly affected by random electron density fluctuations, type III bursts provide us with a unique diagnostic tool for solar wind remote plasma measurements. Here, we performed a statistical survey of 152 simple and isolated type III bursts observed by the twin-spacecraft Solar TErrestrial RElations Observatory mission. We investigated their time–frequency profiles in order to retrieve decay times as a function of frequency. Next, we performed Monte Carlo simulations to study the role of scattering due to random electron density fluctuations on time–frequency profiles of radio emissions generated in the interplanetary medium. For simplification, we assumed the presence of isotropic electron density fluctuations described by a power law with the Kolmogorov spectral index. Decay times obtained from observations and simulations were compared. We found that the characteristic exponential decay profile of type III bursts can be explained by the scattering of the fundamental component between the source and the observer despite restrictive assumptions included in the Monte Carlo simulation algorithm. Our results suggest that relative electron density fluctuations /{n}{{e}} in the solar wind are 0.06–0.07 over wide range of heliospheric distances.

Position-controlled epitaxial III-V nanowires on silicon

NARCIS (Netherlands)

Roest, A.L.; Verheijen, M.A.; Wunnicke, O.; Serafin, S.N.; Wondergem, H.J.; Bakkers, E.P.A.M.

2006-01-01

We show the epitaxial integration of III-V semiconductor nanowires with silicon technology. The wires are grown by the VLS mechanism with laser ablation as well as metal-organic vapour phase epitaxy. The hetero-epitaxial growth of the III-V nanowires on silicon was confirmed with x-ray diffraction

Spectral responses in near-infrared of the mixed compounds III-V ternary and quaternary, based on GaSb

Science.gov (United States)

Mbow, B.; Rezzoug, N.; Peremarti, C.; Mezerreg, A.; Llinares, C.

1993-09-01

From the simulation of the spectral response of the different photodetector devices elaborated in our laboratory (C.E.M.), we determine the influence of geometrical and physical parameters in order to achieve the best photodetector operating at the wavelength 2.55 μm. In this paper we present: Gao{0.6}In{0.4}Sbn/Ga{0.6}In{0.4}Sbp homojunctions matched on GaSbp substrate, Ga{0.75}In{0.25}As{0.23}Sbp/GaSbn ternary heterojunction and GaSbp/Ga{0.74}In{0.26}As{0.23}Sb0.77p/GaSbn quaternary heterojunction. The GaSbp layer with an energy band gap greater than Ga{0.74}In{0.26}As{0.23}Sb0.77p optical gap will act as a window, reducing the effect of surface recombinaison. Results of the simulation are compared to experimental curves to determine the values of photoelectrical parameters (diffusion length, recombination velocity at the surface ...). Les mesures de réponse spectrale dans la gamme [0,4 eV à 2 eV] ont été effectuées sur des homojonctions, Ga{0,6}In{0,4}Sbn/Ga{0,6}In{0,4}Sbp déposées sur un substrat de GaSb et des hétérostructures ternaires Ga{0,75}In{0,25}Sbp/GaSbn et quaternaires GaSbp/Ga{0,74}In{0,26}As{0,23}Sb0,77p/GaSbn. La couche de GaSbp avec un gap plus grand que celui de Ga{0,74}In{0,26}As{0,23}Sb0,77p joue le rôle d'effet fenêtre. En s'appuyant sur les résultats de la simulation et en accordant les spectres expérimentaux aux spectres théoriques, on détermine les valeurs des paramètres photoélectriques (longueurs de diffusion, les vitesses de recombinaison en surface ... ) intervenant dans le rendement quantique.

Hybrid III-V-on-Si Vertical Cavity laser for Optical Interconnects

DEFF Research Database (Denmark)

Park, Gyeong Cheol; Semenova, Elizaveta; Chung, Il-Sug

2013-01-01

Combining a III-V active material onto the Si platform is an attractive approach for silicon photonics light source. We have developed fabrication methods for novel III-V on Si vertical cavity lasers.......Combining a III-V active material onto the Si platform is an attractive approach for silicon photonics light source. We have developed fabrication methods for novel III-V on Si vertical cavity lasers....

Electrical properties of dislocations in III-Nitrides

Energy Technology Data Exchange (ETDEWEB)

Cavalcoli, D.; Minj, A.; Pandey, S.; Cavallini, A. [Physics and Astronomy Dept. University of Bologna, Italy viale C Berti Pichat 6/II, Bologna (Italy)

2014-02-21

Research on GaN, AlN, InN (III-N) and their alloys is achieving new heights due their high potential applications in photonics and electronics. III-N semiconductors are mostly grown epitaxially on sapphire, and due to the large lattice mismatch and the differences in the thermal expansion coefficients, the structures usually contain many threading dislocations (TDs). While their structural properties have been widely investigated, their electrical characteristics and their role in the transport properties of the devices are still debated. In the present contribution we will show conductive AFM studies of TDs in GaN and Al/In GaN ternary alloys to evidence the role of strain, different surface polarity and composition on their electrical properties. Local I-V curves measured at TDs allowed us to clarify their role in the macroscopic electrical properties (leakage current, mobilities) of III-N based devices. Samples obtained by different growers (AIXTRON, III-V Lab) were studied. The comparison between the results obtained in the different alloys allowed us to understand the role of In and Al on the TDs electrical properties.

Electrical properties of dislocations in III-Nitrides

Science.gov (United States)

Cavalcoli, D.; Minj, A.; Pandey, S.; Cavallini, A.

2014-02-01

Research on GaN, AlN, InN (III-N) and their alloys is achieving new heights due their high potential applications in photonics and electronics. III-N semiconductors are mostly grown epitaxially on sapphire, and due to the large lattice mismatch and the differences in the thermal expansion coefficients, the structures usually contain many threading dislocations (TDs). While their structural properties have been widely investigated, their electrical characteristics and their role in the transport properties of the devices are still debated. In the present contribution we will show conductive AFM studies of TDs in GaN and Al/In GaN ternary alloys to evidence the role of strain, different surface polarity and composition on their electrical properties. Local I-V curves measured at TDs allowed us to clarify their role in the macroscopic electrical properties (leakage current, mobilities) of III-N based devices. Samples obtained by different growers (AIXTRON, III-V Lab) were studied. The comparison between the results obtained in the different alloys allowed us to understand the role of In and Al on the TDs electrical properties.

Preservation of water samples for arsenic(III/V) determinations: An evaluation of the literature and new analytical results

Science.gov (United States)

McCleskey, R. Blaine; Nordstrom, D. Kirk; Maest, A.S.

2004-01-01

Published literature on preservation procedures for stabilizing aqueous inorganic As(III/V) redox species contains discrepancies. This study critically evaluates published reports on As redox preservation and explains discrepancies in the literature. Synthetic laboratory preservation experiments and time stability experiments were conducted for natural water samples from several field sites. Any field collection procedure that filters out microorganisms, adds a reagent that prevents dissolved Fe and Mn oxidation and precipitation, and isolates the sample from solar radiation will preserve the As(III/V) ratio. Reagents that prevent Fe and Mn oxidation and precipitation include HCl, H 2SO4, and EDTA, although extremely high concentrations of EDTA are necessary for some water samples high in Fe. Photo-catalyzed Fe(III) reduction causes As(III) oxidation; however, storing the sample in the dark prevents photochemical reactions. Furthermore, the presence of Fe(II) or SO 4 inhibits the oxidation of As(III) by Fe(III) because of complexation reactions and competing reactions with free radicals. Consequently, fast abiotic As(III) oxidation reactions observed in the laboratory are not observed in natural water samples for one or more of the following reasons: (1) the As redox species have already stabilized, (2) most natural waters contain very low dissolved Fe(III) concentrations, (3) the As(III) oxidation caused by Fe(III) photoreduction is inhibited by Fe(II) or SO4.

Preservation of water samples for arsenic(III/V) determinations: an evaluation of the literature and new analytical results

International Nuclear Information System (INIS)

McCleskey, R.Blaine; Nordstrom, D.Kirk; Maest, Ann S.

2004-01-01

Published literature on preservation procedures for stabilizing aqueous inorganic As(III/V) redox species contains discrepancies. This study critically evaluates published reports on As redox preservation and explains discrepancies in the literature. Synthetic laboratory preservation experiments and time stability experiments were conducted for natural water samples from several field sites. Any field collection procedure that filters out microorganisms, adds a reagent that prevents dissolved Fe and Mn oxidation and precipitation, and isolates the sample from solar radiation will preserve the As(III/V) ratio. Reagents that prevent Fe and Mn oxidation and precipitation include HCl, H 2 SO 4 , and EDTA, although extremely high concentrations of EDTA are necessary for some water samples high in Fe. Photo-catalyzed Fe(III) reduction causes As(III) oxidation; however, storing the sample in the dark prevents photochemical reactions. Furthermore, the presence of Fe(II) or SO 4 inhibits the oxidation of As(III) by Fe(III) because of complexation reactions and competing reactions with free radicals. Consequently, fast abiotic As(III) oxidation reactions observed in the laboratory are not observed in natural water samples for one or more of the following reasons: (1) the As redox species have already stabilized, (2) most natural waters contain very low dissolved Fe(III) concentrations, (3) the As(III) oxidation caused by Fe(III) photoreduction is inhibited by Fe(II) or SO 4

Analysis and evaluation for practical application of photovoltaic power generation system. Analysis and evaluation for development of extra-high efficiency solar cells (fundamental research on extra-high efficiency III-V compound semiconductor tandem solar cells); Taiyoko hatsuden system jitsuyoka no tame no kaiseki hyoka. Chokokoritsu taiyo denchi no gijutsu kaihatsu no tame no kaiseki hyoka (chokokoritsu III-V zoku kagobutsu taiyo denchi gijutsu kaihatsu)

Energy Technology Data Exchange (ETDEWEB)

Sekikawa, T; Kawanami, H; Sakata, I; Nagai, K; Matsumoto, K; Miki, K [Electrotechnical Laboratory, Tsukuba (Japan)

1994-12-01

Described herein are the results of the FY1994 research program for development of extra-high efficiency III-V compound semiconductor tandem solar cells. Heteroepitaxial structures of compound semiconductors, such as GaAs, on silicon substrates are analyzed and evaluated by EXAFS, Raman and RHEED for the initial stage of the film growth and heterointerfaces. The device capable of in-situ observation of the growing surface structures during the period of heteroepitaxial film growth is introduced, to investigate the effects of rise-up and initial growth conditions on defects. The effects of atomic hydrogen on growth of a GaAs film on a silicon substrate are investigated from photoluminescence and solar cell characteristics, to confirm the effects of reducing defects. Heteroepitaxial growth of InGaP, which has the optimum band width for forming multi-junction silicon solar cells, on a silicon substrate is investigated, to find that an interfacial buffer layer is necessary to form a good film. 2 figs.

ACRIM III Level 2 Daily Mean Data V001

Data.gov (United States)

National Aeronautics and Space Administration — Active Cavity Radiometer Irradiance Monitor (ACRIM) III Level 2 Daily Mean Data product consists of Level 2 total solar irradiance in the form of daily means...

Th(As(III)4As(V)4O18): a mixed-valent oxoarsenic(III)/arsenic(V) actinide compound obtained under extreme conditions.

Science.gov (United States)

Yu, Na; Klepov, Vladislav V; Kegler, Philip; Bosbach, Dirk; Albrecht-Schmitt, Thomas E; Alekseev, Evgeny V

2014-08-18

A high-temperature/high-pressure method was employed to investigate phase formation in the Th(NO3)4·5H2O-As2O3-CsNO3 system. It was observed that an excess of arsenic(III) in starting system leads to the formation of Th(As(III)4As(V)4O18), which is representative of a rare class of mixed-valent arsenic(III)/arsenic(V) compounds. This compound was studied with X-ray diffraction, energy-dispersive X-ray, and Raman spectroscopy methods. Crystallographic data show that Th(As(III)4As(V)4O18) is built from (As(III)4As(V)4O18)(4-) layers connected through Th atoms. The arsenic layers are found to be isoreticular to those in previously reported As2O3 and As3O5(OH), and the geometric differences between them are discussed. Bands in the Raman spectrum are assigned with respect to the presence of AsO3 and AsO4 groups.

Hybrid III-V/SOI Resonant Cavity Photodetector

DEFF Research Database (Denmark)

Learkthanakhachon, Supannee; Taghizadeh, Alireza; Park, Gyeong Cheol

2016-01-01

A hybrid III-V/SOI resonant cavity photo detector has been demonstrated, which comprises an InP grating reflectorand a Si grating reflector. It can selectively detects an incident light with 1.54-µm wavelength and TM polarization.......A hybrid III-V/SOI resonant cavity photo detector has been demonstrated, which comprises an InP grating reflectorand a Si grating reflector. It can selectively detects an incident light with 1.54-µm wavelength and TM polarization....

Elemental abundance analyses with DAO spectrograms: XXXII. HR 6455 (A3 III), δ Aqr (A3 V), η Lep (F2 V), and 1 Boo (A1 V)

Science.gov (United States)

Yüce, K.; Adelman, S. J.; Gulliver, A. F.; Hill, G.

2011-08-01

We examine the sharp-lined stars HR 6455 (A3 III, v sin i = 8.7 km s-1) and η Lep (F2 V, v sin i = 13.5 km s-1) as well as δ Aqr (A3 V, v sin i = 81 km s-1) and 1 Boo (A1 V, v sin i = 59 km s-1) to increase the number consistently analyzed A and F stars using high dispersion and high S/N (≥200) spectrograms obtained with CCD detectors at the long Coudé camera of the 1.22-m telescope of the Dominion Astrophysical Observatory. Such studies contribute to understanding systematic abundance differences between normal and non-magnetic main-sequence band chemically peculiar A and early F stars. LTE fine analyses of HR 6455, δ Aqr, and 1 Boo using Kurucz's ATLAS suite programs show the same general elemental abundance trends with differences in the metal richness. Light and iron-peak element abundances are generally solar or overabundant while heavy element and rare earth element abundances are overabundant. HR 6455 is an evolved Am star while δ Aqr and 1 Boo show the phenomenon to different extents. Most derived abundances of η Lep are solar. Table 3 is available at the CDS via http://cdsarc.u-strasbg.fr/cgi-bin/qcat?J/AN/332/681

Crystallization, data collection and processing of the chymotrypsin–BTCI–trypsin ternary complex

Energy Technology Data Exchange (ETDEWEB)

Esteves, Gisele Ferreira; Teles, Rozeni Chagas Lima; Cavalcante, Nayara Silva; Neves, David; Ventura, Manuel Mateus [Laboratório de Biofísica, Instituto de Ciências Biológicas, Universidade de Brasília, 70910-900 Brasília-DF (Brazil); Barbosa, João Alexandre Ribeiro Gonçalves, E-mail: joao@lnls.br [Center for Structural Molecular Biology (CeBiME), Brazilian Synchrotron Light Laboratory (LNLS), CP 6192, 13083-970 Campinas-SP (Brazil); Freitas, Sonia Maria de, E-mail: joao@lnls.br [Laboratório de Biofísica, Instituto de Ciências Biológicas, Universidade de Brasília, 70910-900 Brasília-DF (Brazil)

2007-12-01

A ternary complex of the proteinase inhibitor (BTCI) with trypsin and chymotrypsin was crystallized and its crystal structure was solved by molecular replacement. A ternary complex of the black-eyed pea trypsin and chymotrypsin inhibitor (BTCI) with trypsin and chymotrypsin was crystallized by the sitting-drop vapour-diffusion method with 0.1 M HEPES pH 7.5, 10%(w/v) polyethylene glycol 6000 and 5%(v/v) 2-methyl-2,4-pentanediol as precipitant. BTCI is a small protein with 83 amino-acid residues isolated from Vigna unguiculata seeds and is able to inhibit trypsin and chymotrypsin simultaneously by forming a stable ternary complex. X-ray data were collected from a single crystal of the trypsin–BTCI–chymotrypsin ternary complex to 2.7 Å resolution under cryogenic conditions. The structure of the ternary complex was solved by molecular replacement using the crystal structures of the BTCI–trypsin binary complex (PDB code) and chymotrypsin (PDB code) as search models.

Crystallization, data collection and processing of the chymotrypsin–BTCI–trypsin ternary complex

International Nuclear Information System (INIS)

Esteves, Gisele Ferreira; Teles, Rozeni Chagas Lima; Cavalcante, Nayara Silva; Neves, David; Ventura, Manuel Mateus; Barbosa, João Alexandre Ribeiro Gonçalves; Freitas, Sonia Maria de

2007-01-01

A ternary complex of the proteinase inhibitor (BTCI) with trypsin and chymotrypsin was crystallized and its crystal structure was solved by molecular replacement. A ternary complex of the black-eyed pea trypsin and chymotrypsin inhibitor (BTCI) with trypsin and chymotrypsin was crystallized by the sitting-drop vapour-diffusion method with 0.1 M HEPES pH 7.5, 10%(w/v) polyethylene glycol 6000 and 5%(v/v) 2-methyl-2,4-pentanediol as precipitant. BTCI is a small protein with 83 amino-acid residues isolated from Vigna unguiculata seeds and is able to inhibit trypsin and chymotrypsin simultaneously by forming a stable ternary complex. X-ray data were collected from a single crystal of the trypsin–BTCI–chymotrypsin ternary complex to 2.7 Å resolution under cryogenic conditions. The structure of the ternary complex was solved by molecular replacement using the crystal structures of the BTCI–trypsin binary complex (PDB code) and chymotrypsin (PDB code) as search models

III-Nitride Membranes for Thermal Bio-Sensing and Solar Hydrogen Generation

KAUST Repository

Elafandy, Rami Tarek Mahmoud

2017-09-01

III-nitride nanostructures have generated tremendous scientific and technological interests in studying and engineering their low dimensional physics phenomena. Among these, 2D planar, free standing III-nitride nanomembranes are unrivalled in their scalability for high yield manufacture and can be mechanically manipulated. Due to the increase in their surface to volume ratio and the manifestation of quantum phenomena, these nanomembranes acquire unique physical properties. Furthermore, III-nitride membranes are chemically stable and biocompatible. Finally, nanomembranes are highly flexible and can follow curvilinear surfaces present in biological systems. However, being free-standing, requires especially new techniques for handling nanometers or micrometers thick membrane devices. Furthermore, effectively transferring these membrane devices to other substrates is not a direct process which requires the use of photoresists, solvents and/or elastomers. Finally, as the membranes are transferred, they need to be properly attached for subsequent device fabrications, which often includes spin coating and rinsing steps. These engineering complications have impeded the development of novel devices based on III-nitride membranes. In this thesis, we demonstrate the versatility of III-nitride membranes where we develop a thermal bio-sensor nanomembrane and solar energy photo-anode membrane. First, we present a novel preparation technique of nanomembranes with new characteristics; having no threading dislocation cores. We then perform optical characterization to reveal changes in their defect densities compared to the bulk crystal. We also study their mechanical properties where we successfully modulate their bandgap emission by 55 meV through various external compressive and tensile strain fields. Furthermore, we characterize the effect of phonon-boundary scattering on their thermal properties where we report a reduction of thermal conductivity from 130 to 9 W/mK. We employ

Electrochemical behavior of ruthenium (III), rhodium (III) and palladium (II) in 1-butyl-3-methylimidazolium chloride ionic liquid

Energy Technology Data Exchange (ETDEWEB)

Jayakumar, M.; Venkatesan, K.A. [Fuel Chemistry Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Srinivasan, T.G. [Fuel Chemistry Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)], E-mail: tgs@igcar.gov.in; Vasudeva Rao, P.R. [Fuel Chemistry Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)

2009-11-01

Electrochemical behavior of ruthenium (III), rhodium (III) and palladium (II) in 1-butyl-3-methylimidazolium chloride (bmimCl) and their ternary and binary solutions in bmimCl was studied at various working electrodes at 373 K by cyclic voltammetry and chronoamperometry. Ruthenium (III) chloride forms a stable solution with bmimCl and the cyclic voltammogram of ruthenium (III) in bmimCl recorded at glassy carbon electrode consisted of several redox waves due to the complex nature of ruthenium to exist in several oxidation states. Electrolysis of ruthenium (III) chloride in bmimCl at the cathodic limit of bmimCl (-1.8 V (vs. Pd)) did not result in ruthenium metal deposition. However, it was deposited from bmimPF{sub 6} and bmimNTf{sub 2} room temperature ionic liquids at -0.8 V (vs. Pd). The electrochemical behavior of ruthenium (III) in bmimCl in the presence of palladium (II) and rhodium (III) was studied by cyclic voltammetry. The presence of palladium (II) in bmimCl favors underpotential deposition of ruthenium metal. The nuclear loop at -0.5 V (vs. Pd) was observed in all solutions when palladium (II) co-existed with other two metal ions. Nucleation and growth of the metal on glassy carbon working electrode was investigated by chronoamperometry. The growth and decay of chronocurrents has been found to follow the instantaneous nucleation model with three-dimensional growth of nuclei.

Prospects of Ternary Cd1-x Zn x S as an Electron Transport Layer and Associated Interface Defects in a Planar Lead Halide Perovskite Solar Cell via Numerical Simulation

Science.gov (United States)

Chowdhury, Towhid Hossain; Ferdaous, Mohammad Tanvirul; Wadi, Mohd. Aizat Abdul; Chelvanathan, Puvaneswaran; Amin, Nowshad; Islam, Ashraful; Kamaruddin, Nurhafiza; Zin, Muhammad Irsyamuddin M.; Ruslan, Mohd Hafidz; Sopian, Kamaruzzaman Bin; Akhtaruzzaman, Md.

2018-03-01

In this study we present a ternary alloy, Cd1-x Zn x S as an electron transport layer for a planar lead halide perovskite solar cell via numerical simulation with solar cell capacitance simulator (SCAPS) software. Performance dependence on molar composition variation in the Cd1-x Zn x S alloy was studied for the mixed perovskite CH3NH3PbI3-x Cl x absorber and spiro-OMeTAD hole transport material in a planar perovskite solar cell. Additionally, the defects on both Cd1-x Zn x S/CH3NH3PbI3-x Cl x and CH3NH3PbI3-x Cl x /spiro-OMeTAD interface were thoroughly investigated. Simultaneously, a thickness of 700 nm for CH3NH3PbI3-x Cl x absorber with 50-nm-thick Cd0.2Zn0.8S (x = 0.8) was optimized. Analysis of the numerical solutions via SCAPS provides a trend and pattern for Cd0.2Zn0.8S as an effective electron transport layer for planar perovskite solar cells with a yield efficiency up to 24.83%. The planar perovskite solar cell shows an open-circuit voltage of 1.224 V, short-circuit current density of 25.283 mA/cm2 and a fill factor of 80.22.

Ultrabroadband Hybrid III-V/SOI Grating Reflector for On-chip Lasers

DEFF Research Database (Denmark)

Park, Gyeong Cheol; Taghizadeh, Alireza; Chung, Il-Sug

2016-01-01

We report on a new type of III-V/SOI grating reflector with a broad stopband of 350 nm. This reflector has promising prospects for applications in high-speed III-V/SOI vertical cavity lasers with an improved heat dissipation capability.......We report on a new type of III-V/SOI grating reflector with a broad stopband of 350 nm. This reflector has promising prospects for applications in high-speed III-V/SOI vertical cavity lasers with an improved heat dissipation capability....

Zwitterion-functionalized polymer microspheres as a sorbent for solid phase extraction of trace levels of V(V), Cr(III), As(III), Sn(IV), Sb(III) and Hg(II) prior to their determination by ICP-MS.

Science.gov (United States)

Jia, Xiaoyu; Gong, Dirong; Zhao, Junyi; Ren, Hongyun; Wang, Jiani; Zhang, Xian

2018-03-19

This paper describes the preparation of zwitterion-functionalized polymer microspheres (ZPMs) and their application to simultaneous enrichment of V(V), Cr(III), As(III), Sn(IV), Sb(III) and Hg(II) from environmental water samples. The ZPMs were prepared by emulsion copolymerization of ethyl methacrylate, 2-diethylaminoethyl methacrylate and triethylene glycol dimethyl acrylate followed by modification with 1,3-propanesultone. The components were analyzed by elemental analyses as well as Fourier transform infrared spectroscopy, and the structures were characterized by scanning electron microscopy and transmission electron microscopy. The ZPMs were packed into a mini-column for on-line solid-phase extraction (SPE) of the above metal ions. Following extraction with 40 mM NH 4 NO 3 and 0.5 M HNO 3 solution, the ions were quantified by ICP-MS. Under the optimized conditions, the enrichment factors (from a 40 mL sample) are up to 60 for the ions V(V), As(III), Sb(III) and Hg(II), and 55 for Cr(III) and Sn(IV). The detection limits are 1.2, 3.4, 1.0, 3.7, 2.1 and 1.6 ng L -1 for V(V), Cr(III), As(III), Sn(IV), Sb(III) and Hg(II), respectively, and the relative standard deviations (RSDs) are below 5.2%. The feasibility and accuracy of the method were validated by successfully analyzing six certified reference materials as well as lake, well and river waters. Graphical abstract Zwitterion-functionalized polymer microspheres (ZPMs) were prepared and packed into a mini-column for on-line solid-phase extraction (SPE) via pump 1. Then V(V), Cr(III), As(III), Sn(IV), Sb(III) and Hg(II) ions in environmental waters were eluted and submitted to ICP-MS via pump 2.

Theoretical study of quaternary compounds as thin-film solar cell absorber

International Nuclear Information System (INIS)

Su, Huai Wei

2010-01-01

Full text : Design of chalcogenide photovoltaic absorbers is carried out systematically through sequential cation mutation, from binary to ternary to quaternary compounds, using first-principles electronic structure calculations. Several universal trends are found for the ternary and two classes of quaternary chalcogenides. For example, the lowest-energy structure always has larger lattice constant a, smaller tetragonal distortion parameter η=c/2a, and larger band gap than the metastable structures for common-row cation mutations. The band gap is reduced during the mutation. The band gap decreases from binary II-VI to ternary I-III-VI 2 are mostly due to the p-d repulsion in the valence band, the decreases from ternary I-III-VI 2 to quaternary I 2 -II-IV-VI 4 chalcogenides are due to the downshift in the conduction band caused by the wavefunction localization on the group IV cation site. It was found that I 2 -II-IV-VI 4 compounds are more stable in the kesterite structure, whereas the widely-assumed stannite structure reported in the literature is most likely due to partial disorder in the I-II layer of the kesterite phase. Among the derived quaternary compounds, Cu 2 ZnSnS 4 (CZTS) is one of the ideal candidate absorber materials for thin-film solar cells with an optimal band gap, high absorption coefficient, abundant elemental components, and is adaptable to various growth techniques. It was performed a series of first-principles electronic structure calculations for CZTS. Also it was found that in the ground state kesterite structure, (i) the chemical potential region that CZTS can form is very small. Therefore, it will be very difficult to obtain high quality stoichiometric CZTS samples; (ii) The dominant p-type acceptor in CZTS is CuZn, however, the associated acceptor level is relatively high, suggesting that p-type doping in CZTS is more difficult than ternary compounds such as CuInSe 2 ; (iii) The formation of the self-compensated defect pair [Cu

Surface passivation technology for III-V semiconductor nanoelectronics

International Nuclear Information System (INIS)

Hasegawa, Hideki; Akazawa, Masamichi

2008-01-01

The present status and key issues of surface passivation technology for III-V surfaces are discussed in view of applications to emerging novel III-V nanoelectronics. First, necessities of passivation and currently available surface passivation technologies for GaAs, InGaAs and AlGaAs are reviewed. Then, the principle of the Si interface control layer (ICL)-based passivation scheme by the authors' group is introduced and its basic characterization is presented. Ths Si ICL is a molecular beam epitaxy (MBE)-grown ultrathin Si layer inserted between III-V semiconductor and passivation dielectric. Finally, applications of the Si ICL method to passivation of GaAs nanowires and GaAs nanowire transistors and to realization of pinning-free high-k dielectric/GaAs MOS gate stacks are presented

Volume dependence of T/sub c/ of Ternary A-15 Phases

International Nuclear Information System (INIS)

Shamrai, V.

1984-01-01

Results are presented of measurements of the superconducting transition temperature T/sub c/, lattice constant a, magnetic susceptibility /sub chi/, and critical field H/sub c/ 2 for many Nb 3 Al and V 3 Si-based ternary phases and Nb 3 SnH/sub x/. For V 3 Si-based ternary systems and Nb 3 SnH/sub x/ the density of states at the Fermi level N(epsilon/sub F/) sharply decreases with the concentration of the alloying element. The variation of N(epsilon/sub F/) in these ternary systems cannot be explained by the variation of a. In ternary phases Nb 3 (Al/sub 1-x/dY/sub x/), where Y can be Ge, Ga, Sb, or Se, a quite clear correlation is revealed between T/sub c/ and a. The dependence of T/sub c/ on V in these systems is due to the variation of the matrix element of the electron-phonon interaction 2 >

Temperature Measurements in the Solar Transition Region Using N III Line Intensity Ratios

Science.gov (United States)

Doron, R.; Doschek, G. A.; Laming, J. M.; Feldman, U.; Bhatia, A. K.

2003-01-01

UV emission from B-like N and O ions a rather rare opportunity for recording spectral lines in a narrow wavelength range that can potentially be used to derive temperatures relevant to the solar transition region. In these ions, the line intensity ratios of the type (2s2p(sup 2) - 2p(sup 3)) / (2s(sup 2)2p - 2s2p(sup 2)) are very sensitive to the electron temperature. Additionally, the lines involving the ratios fall within a range of only - 12 A; in N III the lines fall in the 980 - 992 A range and in O IV in the 780 - 791 A range. In this work, we explore the use of these atomic systems, primarily in N III, for temperature diagnostics of the transition region by analyzing UV spectra obtained by the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) spectrometer flown on the Solar and Heliospheric Observatory (SOHO). The N III temperature-sensitive line ratios are measured in more than 60 observations. Most of the measured ratios correspond to temperatures in the range 5.7x10(exp 4) - 6.7x10(exp 4) K. This range is considerably lower than the calculated temperature of maximum abundance of N III, which is approx. 7.6x10(exp 4) K. Detailed analysis of the spectra further indicates that the measured ratios are probably somewhat overestimated due to resonant scattering effects in the 2s(sup 2)2p - 2s2p(sup 2) lines and small blends in the 2s2p(sup 2) - 2p3 lines. Actual lower ratios would only increase the disagreement between the ionization balance calculations and present temperature measurements based on a collisional excitation model. In the case of the O IV spectra, we determined that due to the close proximity in wavelength of the weak line (2s2p(sup 2)-2p3 transitions) to a strong Ne VIII line, sufficiently accurate ratio measurements cannot be obtained. Subject headings: atomic data --- atomic processes --- Sun: transition region --- Sun: U V radiation --- techniques: spectroscopic

NiS and MoS2 nanosheet co-modified graphitic C3N4 ternary heterostructure for high efficient visible light photodegradation of antibiotic.

Science.gov (United States)

Lu, Xuejun; Wang, Yu; Zhang, Xinyi; Xu, Guangqing; Wang, Dongmei; Lv, Jun; Zheng, Zhixiang; Wu, Yucheng

2018-01-05

The development of efficient solar driven catalytic system for the degradation of antibiotics has become increasingly important in environmental protection and remediation. Non-noble-metal NiS and MoS 2 nanosheet co-modified graphitic C 3 N 4 ternary heterostructure has been synthesized via a facile combination of hydrothermal and ultrasound method, and the ternary heterostructure has been utilized for photocatalytic degradation of antibiotic agents. The antibiotics of ciprofloxacin (CIP) and tetracycline hydrochloride (TC) were photodegraded by the hybrid under the visible light. The optimal photodegradation rate of the ternary heterostructure reaches about 96% after 2h irradiation, which is 2.1 times higher than that of pure g-C 3 N 4 for TC degradation. The photocatalytic degradation rates of the ternary heterostructure for both CIP and TC obey the pseudo-first-order kinetic model. The enhanced visible light adsorption and charge separation efficiency contribute to the photocatalytic performance of the ternary heterostructure. This work provides new insights and pathways by which efficient degradation of antibiotics can be achieved and will stimulate further studies in this important field. Copyright © 2017 Elsevier B.V. All rights reserved.

Influence of carrier concentration on the performance of CIAS solar cell

Science.gov (United States)

Patel, Kinjal; Ray, Jaymin

2018-05-01

Photovoltaic research has moved beyond the use of single crystalline materials such as Group IV elemental Si and Group III-V compounds like GaAs to much more complex compounds of the Group I-III-VI2 with chalcopyrite structure. The ternary ABC2 chalcopyrites (A=Cu; B=In, Ga or Al; C= S, Se or Te) form a large group of semiconducting materials with diverse structural and electrical properties. These materials are attractive for thin film photovoltaic application for a number of reasons. The bandgap of CuInSe2 is relatively low, 1.04 eV, but it can be adjusted to better match the solar spectrum either by substituting part of In by Ga or part of Se by S. Most reported and popular Cu(In,Ga)Se2 (CIGS) is one of its derivative. Efficiency of the CIGS devices with Eg >1.3 eV is reduced by the degradation of the electronic properties of the absorber leading to losses in the fill-factor and the open-circuit voltage. Alternatively, the performance can be improved by the addition of Al to form CuInAlSe2 (CIAS) absorber layers with an increase in the bandgap energy, which matches closely with the solar spectrum. In the present work an effort was made in the direction of improving the conversion efficiency by studying the influence of carrier concentration. SCAPS simulation program is used to simulate the CIAS structure numerically. The obtained results intended the significant variation in the values of conversion efficiency. Variation in the efficiency can be considered because of the relation optical absorption and carrier concentration. Observed highest efficiency is 10 %, which can be further improved by considering actual parameters of the device as well as the operating condition.

Thin-layer chromatography of ternary complexes of group-IIIA metals with 2-thenoyltrifluoroacetone and 2,2'-bipyridyl on cellulose layer

Energy Technology Data Exchange (ETDEWEB)

Chao, H E; Saitoh, K; Suzuki, N [Tohoku Univ., Sendai (Japan). Faculty of Science

1980-11-11

Normal phase thin-layer chromatographic behaviour of several ternary complexes of group-IIIA metals with 2-thenoyltrifluoroacetone (TTA) and 2,2'bipyridyl (bpy) has been investigated on cellulose layer. The ternary complexes of lanthanide metals show higher mutual separability than the complexes with TTA alone. Mutual separation of TTA complexes with La(III), Ce(III), Eu(III) or Y(III), Sc(III), Th(IV), and U(VI) has been successfully achieved by two-dimensional TLC, primarily with carbon tetrachloride-benzene (75:25) containing 0.02M TTA, and secondary with carbon tetrachloride-hexane (35:65) containing both 0.02M TTA and 0.02M bpy.

Development of III-Sb Quantum Dot Systems for High Efficiency Intermediate Band Solar Cells

Energy Technology Data Exchange (ETDEWEB)

Huffaker, Diana [Univ. of California, Los Angeles, CA (United States); Hubbard, Seth [Rochester Inst. of Technology, NY (United States); Norman, Andrew [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2015-07-31

This project aimed to develop solar cells that can help reduce cost per watt. This work focused on developing solar cells that utilize quantum dot (QD) nanomaterials to provide multijunction solar cell efficiency at the cost of single junction solar cell. We focused on a novel concept known as intermediate band solar cells (IBSC) where an additional energy band is inserted in a single solar cell to accommodate sub-bandgap photons absorption which otherwise are lost through transmission. The additional energy band can be achieved by growing QDs within a solar cell p-n junction. Though numerous studies have been conducted to develop such QD systems, very small improvements in solar energy conversion efficiency have been reported. This is mainly due to non-optimal material parameters such as band gap, band offset etc. In this work, we identified and developed a novel QD material system that meets the requirements of IBSC more closely than the current state-of-the-art technology. To achieve these goals, we focused on three important areas of solar cell design: band structure calculations of new materials, efficient device design for high efficiency, and development of new semiconductor materials. In this project, we focused on III-Sb materials as they possess a wide range of energy bandgaps from 0.2 eV to 2eV. Despite the difficulty involved in realizing these materials, we were successfully developed these materials through a systematic approach. Materials studied in this work are AlAsSb (Aluminum Arsenide Antimonide), InAlAs (Indium Aluminum Arsenide) and InAs (Indium Arsenide). InAs was used to develop QD layers within AlAsSb and InAlAs p-n junctions. As the QDs have very small volume, up to 30 QD layers been inserted into the p-n junction to enhance light absorption. These QD multi-stack devices helped in understanding the challenges associated with the development of quantum dot solar cells. The results from this work show that the quantum dot solar cells indeed

Research progress of III-V laser bonding to Si

Science.gov (United States)

Bo, Ren; Yan, Hou; Yanan, Liang

2016-12-01

The vigorous development of silicon photonics makes a silicon-based light source essential for optoelectronics' integration. Bonding of III-V/Si hybrid laser has developed rapidly in the last ten years. In the tireless efforts of researchers, we are privileged to see these bonding methods, such as direct bonding, medium adhesive bonding and low temperature eutectic bonding. They have been developed and applied to the research and fabrication of III-V/Si hybrid lasers. Some research groups have made remarkable progress. Tanabe Katsuaki of Tokyo University successfully implemented a silicon-based InAs/GaAs quantum dot laser with direct bonding method in 2012. They have bonded the InAs/GaAs quantum dot laser to the silicon substrate and the silicon ridge waveguide, respectively. The threshold current of the device is as low as 200 A/cm2. Stevan Stanković and Sui Shaoshuai successfully produced a variety of hybrid III-V/Si laser with the method of BCB bonding, respectively. BCB has high light transmittance and it can provide high bonding strength. Researchers of Tokyo University and Peking University have realized III-V/Si hybrid lasers with metal bonding method. We describe the progress in the fabrication of III-V/Si hybrid lasers with bonding methods by various research groups in recent years. The advantages and disadvantages of these methods are presented. We also introduce the progress of the growth of III-V epitaxial layer on silicon substrate, which is also a promising method to realize silicon-based light source. I hope that readers can have a general understanding of this field from this article and we can attract more researchers to focus on the study in this field.

Modeling Three-Terminal III-V/Si Tandem Solar Cells: Preprint

Energy Technology Data Exchange (ETDEWEB)

Warren, Emily L.; Deceglie, Michael G.; Stradins, Paul; Tamboli, Adele C.

2017-06-27

Three-terminal (3T) tandem cells fabricated by combining an interdigitated back contact (IBC) Si device with a wider bandgap top cell have the potential to provide a robust operating mechanism to efficiently capture the solar spectrum without the need to current match sub-cells or fabricate complicated metal interconnects between cells. Here we develop a two dimensional device physics model to study the behavior of IBC Si solar cells operated in a 3T configuration. We investigate how different cell designs impact device performance and discuss the analysis protocol used to understand and optimize power produced from a single junction, 3T device.

Ternary superconductors

International Nuclear Information System (INIS)

Giorgi, A.L.

1987-01-01

Ternary superconductors constitute a class of superconducting compounds with exceptional properties such as high transition temperatures (≅ 15.2 K), extremely high critical fields (H c2 >60 Tesla), and the coexistence of superconductivity and long-range magnetic order. This has generated great interest in the scientific community and resulted in a large number of experimental and theoretical investigations in which many new ternary compounds have been discovered. A review of some of the properties of these ternary compounds is presented with particular emphasis on the ternary molybdenum chalcogenides and the ternary rare earth transition metal tetraborides. The effect of partial substitution of a second metal atom to form pseudoternary compounds is examined as well as some of the proposed correlations between the superconducting transition temperature and the structural and electronic properties of the ternary superconductors

Efficient hydrogen evolution catalysis using ternary pyrite-type cobalt phosphosulphide

KAUST Repository

Cabán-Acevedo, Miguel

2015-09-14

The scalable and sustainable production of hydrogen fuel through water splitting demands efficient and robust Earth-abundant catalysts for the hydrogen evolution reaction (HER). Building on promising metal compounds with high HER catalytic activity, such as pyrite structure cobalt disulphide (CoS 2), and substituting non-metal elements to tune the hydrogen adsorption free energy could lead to further improvements in catalytic activity. Here we present a combined theoretical and experimental study to establish ternary pyrite-type cobalt phosphosulphide (CoPS) as a high-performance Earth-abundant catalyst for electrochemical and photoelectrochemical hydrogen production. Nanostructured CoPS electrodes achieved a geometrical catalytic current density of 10 mA cm at overpotentials as low as 48mV, with outstanding long-term operational stability. Integrated photocathodes of CoPS on n -p-p silicon micropyramids achieved photocurrents up to 35 mA cm at 0 V versus the reversible hydrogen electrode (RHE), onset photovoltages as high as 450 mV versus RHE, and the most efficient solar-driven hydrogen generation from Earth-abundant systems.

Fe(III)-solar light induced degradation of diethyl phthalate (DEP) in aqueous solutions.

Science.gov (United States)

Mailhot, G; Sarakha, M; Lavedrine, B; Cáceres, J; Malato, S

2002-11-01

The degradation of diethyl phthalate (DEP) photoinduced by Fe(III) in aqueous solutions has been investigated under solar irradiation in the compound parabolic collector reactor at Plataforma Solar de Almeria. Hydroxyl radicals *OH, responsible of the degradation, are formed via an intramolecular photoredox process in the excited state of Fe(III) aquacomplexes. The primary step of the reaction is mainly due to the attack of *OH radicals on the aromatic ring. For prolonged irradiations DEP and its photoproducts are completely mineralized due to the regeneration of the absorbing species and the continuous formation of *OH radicals that confers a catalytic aspect to the process. Consequently, the degradation photoinduced by Fe(III) could be an efficient method of DEP removal from water.

Mechanochemically prepared ternary hybrid cathode material for lithium batteries

International Nuclear Information System (INIS)

Posudievsky, Oleg Yu; Kozarenko, Olga A.; Dyadyun, Vyacheslav S.; Jorgensen, Scott W.; Spearot, James A.; Koshechko, Vyacheslav G.; Pokhodenko, Vitaly D.

2013-01-01

Graphical abstract: The presence of macromolecules of an ion-conducting polymer in the composition of the ternary nanocomposite PPy–PEO/V 2 O 5 promotes interfacial transfer of lithium ions and also facilitates faster transport inside the particles of the nanocomposite. -- Highlights: • Two- and three component nanocomposites are prepared via a solvent-free mechanochemical synthesis. • The nanocomposites retain their capacity above 200 mA h g −1 for at least one hundred cycles. • The presence of PEO promotes interfacial transfer of lithium ions and facilitates faster transport inside the nanocomposite. -- Abstract: Ternary host–guest nanocomposite based on vanadium oxide and two polymers with different types of conductivity (ionic and electronic) – polypyrrole (PPy) and polyethylene oxide (PEO) – is prepared by solventless mechanochemical synthesis. The nanocomposite can be reversibly cycled with a specific capacity of ∼200 mA h g −1 for at least one hundred cycles of full charge–discharge as the active component of the positive electrode of lithium batteries. Electrochemical performance of ternary PPy 0.1 PEO 0.15 V 2 O 5 is compared with two-component analog PPy 0.1 V 2 O 5 . The presence of macromolecules of an ion-conducting polymer in the composition of the ternary nanocomposite PPy 0.1 PEO 0.15 V 2 O 5 promotes interfacial transfer of lithium ions and also facilitates faster transport inside the particles of the nanocomposite

Effect of pH on stability constants of Am(III)- and Cm(III)- humate complexes

International Nuclear Information System (INIS)

Samadfam, Mohammad; Jintoku, Takashi; Sato, Seichi; Ohashi, Hiroshi; Mitsugashira, Toshiaki; Hara, Mitsuo; Suzuki, Yoshimitsu

1999-01-01

The apparent stability constants of Am(III)- and Cm(III)-humate complexes were determined by dialysis method at ionic strength 0.1 in the pH range from 3.3 to 5.7 under N 2 bubbling. The Am(III) and Cm(III) loadings were about 10 -7 and 10 -10 mol/dm 3 . The concentrations of Am-241 and Cm-242 tracers were measured by α-spectrometry. It was found that the apparent stability constants were almost identical for both the Am(III)-humate and Cm(III)-humate complexes. The apparent stability constants showed a small pH-dependence, increasing from 10 4.6 at pH 3.3 to 10 5.1 at pH 5.7. The ionization of acidic functional groups of humic acid is possibly the primary factor. Above pH 6, the dialysis membrane was no langer permeable to Am(III) and Cm(III) ions and the apparent stability constant could not be experimentally obtained. The apparent stability constants between pH 6 and pH 8.5 were evaluated by considering that both binary metal-humate and ternary metal-hydroxo-humate complexes exist at pHs above 6. It was assumed that mono-hydroxo-humate complex Am(OH)HA and Cm(OH)HA are the major ternary complexes that exist below pH 9. The overall stability constants for Am(III)- and Cm(III)-humate complexes increased from 10 5.7 at pH 6 to 10 7.2 at pH 8. This implies that the formation of metal-hydroxo-humate species is preferred over the formation of hydroxide species. The apparent overall stability constants can be easily incorporated into geochemical modeling of trivalent actinide migration. The results of the present study show that the apparent stability constants determined experimentally at pH≤6 do not represent the complexation properties at higher pHs and the formation of ternary complexes should be considered in speciation calculations of radionuclides at terrestrial environment. (J.P.N.)

A STATISTICAL STUDY OF SOLAR ELECTRON EVENTS OVER ONE SOLAR CYCLE

International Nuclear Information System (INIS)

Wang Linghua; Lin, R. P.; Krucker, Säm; Mason, Glenn M.

2012-01-01

We survey the statistical properties of 1191 solar electron events observed by the WIND 3DP instrument from 300 keV for a solar cycle (1995 through 2005). After taking into account times of high background, the corrected occurrence frequency of solar electron events versus peak flux exhibits a power-law distribution over three orders of magnitude with exponents between –1.0 and –1.6 for different years, comparable to the frequency distribution of solar proton events, microflares, and coronal mass ejections (CMEs), but significantly flatter than that of soft X-ray (SXR) flares. At 40 keV (2.8 keV), the integrated occurrence rate above ∼0.29 (∼330) cm –2 s –1 sr –1 keV –1 near 1 AU is ∼1000 year –1 (∼600 year –1 ) at solar maximum and ∼35 year –1 (∼25 year –1 ) at solar minimum, about an order of magnitude larger than the observed occurrence rate. We find these events typically extend over ∼45° in longitude, implying the occurrence rate over the whole Sun is ∼10 4 year –1 near solar maximum. The observed solar electron events have a 98.75% association with type III radio bursts, suggesting all type III bursts may be associated with a solar electron event. They have a close (∼76%) association with the presence of low-energy (∼0.02-2 MeV nucleon –1 ), 3 He-rich ( 3 He/ 4 He ≥ 0.01) ion emissions measured by the ACE ULEIS instrument. For these electron events, only ∼35% are associated with a reported GOES SXR flare, but ∼60% appear to be associated with a CME, with ∼50% of these CMEs being narrow. These electrons are often detected down to below 1 keV, indicating a source high in the corona.

True ternary fission of 252Cf

International Nuclear Information System (INIS)

Vijayaraghavan, K.R.; Balasubramaniam, M.; Oertzen, W. von

2014-01-01

Splitting of heavy radioactive nucleus into three fragments is known as ternary fission. If the size of the fragments are almost equal it is referred to as true ternary fission. Recently, Yu. V. Pyatkov et al observed/reported the experimental observation of true ternary fission in 252 Cf. In this work, the possibilities of different true ternary fission modes of 252 Cf through potential energy surface (PES) calculations based on three cluster model (TCM) are discussed. In TCM a condition on the mass numbers of the fission fragments is implied as A 1 ≥ A 2 ≥ A 3 in order to avoid repetition of combinations. Due to this condition, the values of Z 3 vary from 0 to 36 and Z 2 vary from 16 to 51. Of the different pairs having similar (Z 2 , Z 3 ) with different potential energy, a pair possessing minimum potential energy is chosen. Thus identified favourable combinations are plotted. For the PES calculations the arrangement of the fragments is considered in the order of A 1 +A 2 +A 3 . i.e. the heavy and the lightest fragments are kept at the ends. It is seen that the deepest minimum in the PES occurs for Z 3 =2 labelled as (Z 2 ; 2) indicating He accompanied breakup as the most favourable one. Of which, the breakup with Z 2 around 46 to 48 is the least (shown by dashed (Z 1 = 50) and dotted (Z 1 = 52) lines indicating a constant Z 1 value). The other notable minima in the PES are labelled and they correspond to the (Z 2 , Z 3 ) pairs viz., (20, 20), (28, 20), (28, 28) and (32, 32). Of these four minima, the first three are associated with the magic numbers 20 and 28. For Z 3 =20, there are two minimums at (20,20) and (28,20) among them (28,20) is the lowest minimum through which the minimum-path passes, and it is the ternary decay observed by Yu. V. Pyatkov et al. The fourth minima is the most interesting due to the fact that it corresponds to true ternary fission mode with Z 2 =32, Z 3 =32 and Z 1 =34. The minimum potential energy path also goes through this true

Solar cell with back side contacts

Science.gov (United States)

Nielson, Gregory N; Okandan, Murat; Cruz-Campa, Jose Luis; Resnick, Paul J; Wanlass, Mark Woodbury; Clews, Peggy J

2013-12-24

A III-V solar cell is described herein that includes all back side contacts. Additionally, the positive and negative electrical contacts contact compoud semiconductor layers of the solar cell other than the absorbing layer of the solar cell. That is, the positive and negative electrical contacts contact passivating layers of the solar cell.

Back reflectors based on buried Al{sub 2}O{sub 3} for enhancement of photon recycling in monolithic, on-substrate III-V solar cells

Energy Technology Data Exchange (ETDEWEB)

García, I. [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States); Instituto de Energía Solar, Universidad Politécnica de Madrid, Avda Complutense s/n, 28040 Madrid (Spain); Kearns-McCoy, C. F. [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States); Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States); Ward, J. S.; Steiner, M. A.; Geisz, J. F.; Kurtz, S. R. [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)

2014-09-29

Photon management has been shown to be a fruitful way to boost the open circuit voltage and efficiency of high quality solar cells. Metal or low-index dielectric-based back reflectors can be used to confine the reemitted photons and enhance photon recycling. Gaining access to the back of the solar cell for placing these reflectors implies having to remove the substrate, with the associated added complexity to the solar cell manufacturing. In this work, we analyze the effectiveness of a single-layer reflector placed at the back of on-substrate solar cells, and assess the photon recycling improvement as a function of the refractive index of this layer. Al{sub 2}O{sub 3}-based reflectors, created by lateral oxidation of an AlAs layer, are identified as a feasible choice for on-substrate solar cells, which can produce a V{sub oc} increase of around 65% of the maximum increase attainable with an ideal reflector. The experimental results obtained using prototype GaAs cell structures show a greater than two-fold increase in the external radiative efficiency and a V{sub oc} increase of ∼2% (∼18 mV), consistent with theoretical calculations. For GaAs cells with higher internal luminescence, this V{sub oc} boost is calculated to be up to 4% relative (36 mV), which directly translates into at least 4% higher relative efficiency.

Novel materials for high-efficiency solar cells

Science.gov (United States)

Kojima, Nobuaki; Natori, Masato; Suzuki, Hidetoshi; Inagaki, Makoto; Ohshita, Yoshio; Yamaguchi, Masafumi

2009-08-01

Our Toyota Technological Institute group has investigated various novel materials for solar cells from organic to III-V compound materials. In this paper, we report our recent results in conductivity control of C60 thin films by metal-doping for organic solar cells, and mobility improvement of (In)GaAsN compounds for III-V tandem solar cells. The epitaxial growth of Mg-doped C60 films was attempted. It was found that the epitaxial growth of Mg-doped C60 film was enabled by using mica (001) substrate in the low Mg concentration region (Mg/C60 molar ratio defects leads this improvement.

New ternary superconducting germanides

Science.gov (United States)

Moschalkov, V. V.; Muttik, I. G.; Samarin, N. A.; Seropegin, Yu. D.; Rudometkina, M. V.

1991-12-01

We have studied the structure, electrical and magnetic properties of new ternary compounds with germanium and transition metals of IV and V groups (Ti 0.7V 0.3Ge 3, Hf 2V 3Ge, Zr 32-36V 32-36Ge 30-32, Hf 2Nb 3Ge 4, HfVGe, Zr 15-17V 39-40Ge 44-45, Hf 10.8-21.7V 36.0-42.8). The homogeneity fields for all new phases are determined. Resistivity (T) and magnetic susceptibility χ(T) are investigated at T=4.2…300 K. Two new superconductors have been found - Zr 32-36V 32-36Ge 30-32 and HfVGe with T c=4.7 K and 5.7 K, respectively.

Sb{sup III} - Sb{sup V} Exchange Reaction in Hydrochloric: Acid Solutions; Echange Sb{sup III}-Sb{sup V} dans des Solutions d'Acide Chlorhydrique; Reaktsiya obmena Sb(III) - Sb(V) v rastvorakh khloristovodorodnoj kisloty; Intercambio Sb{sup III}-Sb{sup V} en Soluciones de HCl

Energy Technology Data Exchange (ETDEWEB)

Kambara, T.; Yamaguchi, K.; Yasuba, S. [Shizuoka University, Shizuoka City (Japan)

1965-10-15

The exchange reaction of Sb{sup III} - Sb{sup V} in solutions of low HCl concentrations was studied using {sup 124}Sb as a tracer. The effects of HCl concentrations and chemical forms of antimony on the exchange rate were investigated. The HCl concentrations of the antimony solutions ((Sb{sup III}) =(Sb{sup V}) = 6.8 x 10{sup -4}M) were changed from 0.8 to 4.0M and the half-time for the exchange was measured by plotting log (1 - F) versus time t to calculate the exchange rate assuming the second-ordet reaction. It was found that the exchange rate was sharply increased with the increase of HCl concentrations (at 25 Degree-Sign C, from 0.8 to 2.0M) and at 2.0M HCl concentration the rate reached the maximum, from which the rate was decreased with the increase of HCl concentrations (at 25 Degree-Sign C, from 2.0 to 4.0M). Two sorts of Sb{sup V} species were used for our investigations, i.e. one was used directly after the dilution of 10M HCl Sb{sup V} solution with water and the other was used after 24 hours standing at room temperature from the dilution. (The Sb{sup III} species were also kept standing after preparation from 10M HCl Sb{sup III} solution.) In both cases the maximum rates were found to exist at 2.0M HCl concentration. The rate R{sub 1} for the former (directly after dilution) was 4.5 x 10{sup -6} mole litre{sup -1} min{sup -1} and the rate R{sub 2} for the latter (24 hours standing) was 1.2 x 10{sup -}{sub 6} mole litre. Also the activation energy for these cases was found to be 12.2 kcal/mole and 19.1 kcal/mole. By spectrophotometric studies, the Sb{sup V} species of the former type were found to be mainly consisting of SbCl{sup -}{sub 6} and the species of the latter type to be of SbCl{sub 4}(OH){sup -}{sub 2}, etc. Besides these facts the form of Sb{sup III} species was found to have no influence on the exchange rate. A much sharper increase of the exchange rate was observed when the HCl concentration of the antimony solution was fixed at 0.8M and

Electronic structure and lattice properties of metastable III-(N,V) semiconductor systems; Elektronische Struktur und Kristallgittereigenschaften von metastabilen III-(N,V)-Halbleitersystemen

Energy Technology Data Exchange (ETDEWEB)

Guengerich, M.

2007-12-18

This thesis gives an overview of these influences for Ga-V semiconductors (V=P,As,Sb). Lattice vibrations of the ternary alloys Ga(N,P), Ga(N,As) und Ga(N,Sb) are studied and analyzed with respect to the local binding of the N atoms in the host lattices. For the first time, pressure coefficients of the extended host phonons as well as of the N local vibrational modes in Ga(N,As) und Ga(N,P) are determined by Raman spectroscopy under hydrostatic pressure. The relationship between the force constant of the Ga-N bond and the bond length is determined. A central aspect of the thesis is the concentration dependence of optical transitions in Ga(N,P) and Ga(N,As), studied by spectroscopic methods. The impurity levels in both materials are determined by the spatial statistics of the N atoms. (orig.)

Peculiarities of component interaction in {l_brace}Gd, Er{r_brace}-V-Sn Ternary systems at 870 K and crystal structure of RV{sub 6}Sn{sub 6} stannides

Energy Technology Data Exchange (ETDEWEB)

Romaka, L., E-mail: romakal@franko.lviv.ua [Inorganic Chemistry Department, Ivan Franko Lviv National University, Kyryla and Mefodiya str. 6, 79005 Lviv (Ukraine); Stadnyk, Yu. [Inorganic Chemistry Department, Ivan Franko Lviv National University, Kyryla and Mefodiya str. 6, 79005 Lviv (Ukraine); Romaka, V.V. [Department of Materials Engineering and Applied Physics, Lviv Polytechnic National University, Ustyyanovycha Str. 5, 79013 Lviv (Ukraine); Demchenko, P.; Stadnyshyn, M.; Konyk, M. [Inorganic Chemistry Department, Ivan Franko Lviv National University, Kyryla and Mefodiya str. 6, 79005 Lviv (Ukraine)

2011-09-08

Highlights: > {l_brace}Gd, Er{r_brace}-V-Sn ternary systems at 870 K are characterized by formation of stannides with general compositions RV{sub 6}Sn{sub 6}. > Isostructural RV{sub 6}Sn{sub 6} compounds were also found with Y, Dy, Ho, Tm, and Lu. > The crystal structure of RV{sub 6}Sn{sub 6} compounds was determined by powder diffraction method. > Structural analysis showed that RV{sub 6}Sn{sub 6} compounds (R = Gd, Dy-Tm, Lu) are disordered; YV{sub 6}Sn{sub 6} is characterized by structure ordering. - Abstract: The phase equilibria in the Gd-V-Sn and Er-V-Sn ternary systems were studied at 870 K by means of X-ray and metallographic analyses in the whole concentration range. Both Gd-V-Sn and Er-V-Sn systems are characterized by formation of one ternary compound at investigated temperature, with stoichiometry RV{sub 6}Sn{sub 6} (SmMn{sub 6}Sn{sub 6}-type, space group P6/mmm, a = 0.55322(3) nm, c = 0.91949(7) nm for Gd, a = 0.55191(2) nm, c = 0.91869(8) nm for Er). Solubility of the third component in the binary compounds was not observed. Compounds with the SmMn{sub 6}Sn{sub 6}-type were also found with Dy, Ho, Tm, and Lu, while YV{sub 6}Sn{sub 6} compound crystallizes in HfFe{sub 6}Ge{sub 6} structure type. All investigated compounds are the first ternary stannides with rare earth elements and vanadium.

Minor impact of solar flare events accompanied with SRBT III to the ...

African Journals Online (AJOL)

The dynamical behavior of the Sun exhibits a variety of physical phenomena, some of which are still not at all or only barely understood due to the complexity of the structure of the Sun. The aim of this study is to investigate the correlation of solar flare event and solar radio bursts type III that happen on 23rd July 2017.

Thermodynamics of high-pressure ice polymorphs : ices III and V

NARCIS (Netherlands)

Tchijov, [No Value; Ayala, RB; Leon, GC; Nagornov, O

Thermodynamic properties of high-pressure ice polymorphs, ices III and V, are studied theoretically. The results of TIP4P molecular dynamics simulations in the NPT ensemble are used to calculate the temperature dependence of the specific volume of ices III and V at pressures 0.25 and 0.5 GPa,

III-Nitride Membranes for Thermal Bio-Sensing and Solar Hydrogen Generation

KAUST Repository

Elafandy, Rami T.

2017-01-01

demonstrate the versatility of III-nitride membranes where we develop a thermal bio-sensor nanomembrane and solar energy photo-anode membrane. First, we present a novel preparation technique of nanomembranes with new characteristics; having no threading

Stability constants of mixed ligand complexes of lanthanide(III) and yttrium(III) with complexone and substituted salicylic acids

International Nuclear Information System (INIS)

Kolhe, Vishnu; Dwivedi, K.

1996-01-01

Salicylic acid and substituted salicylic acids are potential antimicrobial agents. Binary complexes of salicylic acid and its substituted derivatives with lanthanide(III) and yttrium(III) metal ions have been reported. There are reports on the ternary metal complexing equilibria with some lanthanide(III) and yttrium(III) metal ions involving aminopolycarboxylic acid as one ligand and salicylic acid (SA) and other related compounds as the second ligands. Ethylene glycol bis(2-aminoethylether)- N, N, N', N'-tetraacetic acid (EGTA) is an important member of aminopolycarboxylic acid and finds many applications in medicine and biology. Recently, few ternary complexes have been reported using EGTA as ligand. In view of biological importance of simple and mixed ligand complexes EGTA, SA and DNSA (3,5-dinitrosalicylic acid), a systematic study has been undertaken for the determination of stability constant and the results are reported. (author). 6 refs., 1 fig., 2 tabs

Solar neutrino flux at keV energies

Science.gov (United States)

Vitagliano, Edoardo; Redondo, Javier; Raffelt, Georg

2017-12-01

We calculate the solar neutrino and antineutrino flux in the keV energy range. The dominant thermal source processes are photo production (γ e→ e νbar nu), bremsstrahlung (e+Ze→ Ze+e+νbar nu), plasmon decay (γ→νbar nu), and νbar nu emission in free-bound and bound-bound transitions of partially ionized elements heavier than hydrogen and helium. These latter processes dominate in the energy range of a few keV and thus carry information about the solar metallicity. To calculate their rate we use libraries of monochromatic photon radiative opacities in analogy to a previous calculation of solar axion emission. Our overall flux spectrum and many details differ significantly from previous works. While this low-energy flux is not measurable with present-day technology, it could become a significant background for future direct searches for keV-mass sterile neutrino dark matter.

Ternary complex formation of lanthanides and radiolanthanides with phosphate and serum proteins

International Nuclear Information System (INIS)

Neumaier, B.; Roesch, F.

1999-01-01

Radioyttrium was recently reported to form ternary complexes with phosphate and serum proteins in blood. In the present work it was investigated whether the trivalent radiolanthanides react in a chemically similar way. In systematic binding studies using gel filtration a ternary complex formation between different lanthanides, phosphate and serum proteins could be identified. The tendency to build a ternary compound of the type Ln III - phosphate - serum protein, however, is dependent on the ionic radii of the lanthanides. Whereas the light and transition lanthanides have a strong inclination to build a ternary complex, this tendency is weaker for the heavier ones. Taking into account the high content of phosphate in human blood, the corresponding ternary complexes of radiolanthanides represent an important transport form of these elements in blood. This finding may contribute to an understanding of the nuclear medical observation on the biodistribution of radiolanthanides. The heavy radiolanthanides can be classified as bone seeking metals, whereas the light and transition lanthanide elements accumulate mainly in the liver and the spleen. For the lighter radiolanthanides the corresponding ternary complexes thus represent an important transport form in blood. This physicochemical form of lanthanides mainly results in reticulo endothelial accumulation; on the other hand, the lower tendency of heavier lanthanides leads to preferential skeletal deposition. (orig.)

Methods for enhancing P-type doping in III-V semiconductor films

Science.gov (United States)

Liu, Feng; Stringfellow, Gerald; Zhu, Junyi

2017-08-01

Methods of doping a semiconductor film are provided. The methods comprise epitaxially growing the III-V semiconductor film in the presence of a dopant, a surfactant capable of acting as an electron reservoir, and hydrogen, under conditions that promote the formation of a III-V semiconductor film doped with the p-type dopant. In some embodiments of the methods, the epitaxial growth of the doped III-V semiconductor film is initiated at a first hydrogen partial pressure which is increased to a second hydrogen partial pressure during the epitaxial growth process.

Ternary Weighted Function and Beurling Ternary Banach Algebra l1ω(S

Directory of Open Access Journals (Sweden)

Mehdi Dehghanian

2011-01-01

Full Text Available Let S be a ternary semigroup. In this paper, we introduce our notation and prove some elementary properties of a ternary weight function ω on S. Also, we make ternary weighted algebra l1ω(S and show that l1ω(S is a ternary Banach algebra.

Structure of metal-rich (001) surfaces of III-V compound semiconductors

DEFF Research Database (Denmark)

Kumpf, C.; Smilgies, D.; Landemark, E.

2001-01-01

The atomic structure of the group-III-rich surface of III-V semiconductor compounds has been under intense debate for many years, yet none of the models agrees with the experimental data available. Here we present a model for the three-dimensional structure of the (001)-c(8x2) reconstruction on In......(8 x 2) reconstructions of III-V semiconductor surfaces contain the same essential building blocks....

Single source precursors for fabrication of I-III-VI{sub 2} thin-film solar cells via spray CVD

Energy Technology Data Exchange (ETDEWEB)

Hollingsworth, J.A.; Banger, K.K.; Jin, M.H.-C.; Harris, J.D.; Cowen, J.E.; Bohannan, E.W.; Switzer, J.A.; Buhro, W.E.; Hepp, A.F

2003-05-01

The development of thin-film solar cells on flexible, lightweight, space-qualified substrates provides an attractive cost solution to fabricating solar arrays with high specific power (W/kg). Thin-film fabrication studies demonstrate that ternary single source precursors can be used in either a hot, or cold-wall spray chemical vapour deposition reactor, for depositing CuInS{sub 2}, CuGaS{sub 2} and CuGaInS{sub 2} at reduced temperatures (400-450 sign C), which display good electrical and optical properties suitable for photovoltaic devices. X-ray diffraction studies, energy dispersive spectroscopy and scanning electron microscopy confirmed the formation of the single phase CIS, CGS, CIGS thin-films on various substrates at reduced temperatures.

Influence of hydroxybenzoic acids on the adsorption of Eu(III) onto α,γ-Al_2O_3 particles in mildly acidic conditions: A macroscopic and spectroscopic study

International Nuclear Information System (INIS)

Moreau, Pauline; Colette-Maatouk, Sonia; Gareil, Pierre; Reiller, Pascal E.

2016-01-01

The influence of hydroxybenzoic acids (HAH_n), namely p-hydroxybenzoic acid (4-hydroxybenzoic acid, HPhbH) and protocatechuic acid (3,4-dihydroxybenzoic acid, HProtoH_2), on the adsorption of europium(III) onto α,γ-Al_2O_3 particles is studied as a function of acid concentration. After measuring the adsorption edge of the Eu(III)/α,γ-Al_2O_3 binary system, and using the previously studied binary component system Eu(III)/HAH_n—Moreau et al. (2015) Inorg. Chim. Acta432, 81—, and HAH_n/α,γ-Al_2O_3—Moreau et al. (2013) Colloids Surf. A435, 97—, it is evidenced that HPhbH does not enhance Eu(III) adsorption onto α,γ-Al_2O_3 in the Eu(III)/HPhbH/α,γ-Al_2O_3 ternary system. Conversely, HProtoH_2 enhances Eu(III) adsorption onto α,γ-Al_2O_3 in the Eu(III)/HProtoH_2/α,γ-Al_2O_3 ternary system. Adsorption of the acids are also found higher in the Eu(III)/acid/α,γ-Al_2O_3 ternary systems as compared with the corresponding binary systems assessing synergetic effects. For high HPhbH concentrations, a ternary surface species involving ≡AlOH surface sites, Eu(III), and PhbH"– is evidenced by time-resolved luminescence spectroscopy (TRLS). However, in the Eu(III)/HProtoH_2/α,γ-Al_2O_3 ternary system, chemical environment of Eu(III) is found to be very close to that in the Eu(III)/HProtoH_2 binary system. Ternary surface species could not be evidenced in the Eu(III)/HProtoH_2/α,γ-Al_2O_3 ternary system with TRLS because of the very short decay time of Eu(III) in the presence of protocatechuic acid. - Highlights: • Adsorption in the Eu(III) – hydroxybenzoic acid – alumina system is studied. • Adsorption is quantified and luminescence parameters are obtained independently. • Synergistic effect of organic acids adsorption are evidenced in the ternary systems. • A ternary species is clearly shown for the p-hydrobenzoic acid.

Ternary fission

International Nuclear Information System (INIS)

Wagemans, C.

1991-01-01

Since its discovery in 1946, light (charged) particle accompanied fission (ternary fission) has been extensively studied, for spontaneous as well as for induced fission reactions. The reason for this interest was twofold: the ternary particles being emitted in space and time close to the scission point were expected to supply information on the scission point configuration and the ternary fission process was an important source of helium, tritium, and hydrogen production in nuclear reactors, for which data were requested by the nuclear industry. Significant experimental progress has been realized with the advent of high-resolution detectors, powerful multiparameter data acquisition systems, and intense neutron and photon beams. As far as theory is concerned, the trajectory calculations (in which scission point parameters are deduced from the experimental observations) have been very much improved. An attempt was made to explain ternary particle emission in terms of a Plateau-Rayleigh hydrodynamical instability of a relatively long cylindrical neck or cylindrical nucleus. New results have also been obtained on the so-called open-quotes trueclose quotes ternary fission (fission in three about-equal fragments). The spontaneous emission of charged particles has also clearly been demonstrated in recent years. This chapter discusses the main characteristics of ternary fission, theoretical models, light particle emission probabilities, the dependence of the emission probabilities on experimental variables, light particle energy distributions, light particle angular distributions, correlations between light particle accompanied fission observables, open-quotes trueclose quotes ternary fission, and spontaneous emission of heavy ions. 143 refs., 18 figs., 8 tabs

III-V/Si Tandem Cells Utilizing Interdigitated Back Contact Si Cells and Varying Terminal Configurations: Preprint

Energy Technology Data Exchange (ETDEWEB)

Schnabel, Manuel; Klein, Talysa R.; Jain, Nikhil; Essig, Stephanie; Schulte-Huxel, Henning; Warren, Emily; van Hest, Maikel F. A. M.; Geisz, John; Stradins, Paul; Tamboli, Adele; Rienacker, Michael; Merkle, Agnes; Schmidt, Jan; Brendel, Rolf; Peibst, Robby

2017-07-11

Solar cells made from bulk crystalline silicon (c-Si) dominate the market, but laboratory efficiencies have stagnated because the current record efficiency of 26.3% is already very close to the theoretical limit of 29.4% for a single-junction c-Si cell. In order to substantially boost the efficiency of Si solar cells we have been developing stacked III-V/Si tandem cells, recently attaining efficiencies above 32% in four-terminal configuration. In this contribution, we use state-of-the-art III-V cells coupled with equivalent circuit simulations to compare four-terminal (4T) to three- and two-terminal (3T, 2T) operation. Equivalent circuit simulations are used to show that tandem cells can be operated just as efficiently using three terminals as with four terminals. However, care must be taken not to overestimate 3T efficiency, as the two circuits used to extract current interact, and a method is described to accurately determine this efficiency. Experimentally, a 4T GaInP/Si tandem cell utilizing an interdigitated back contact cell is shown, exhibiting a 4T efficiency of 31.5% and a 2T efficiency of 28.1%. In 3T configuration, it is used to verify the finding from simulation that 3T efficiency is overestimated when interactions between the two circuits are neglected. Considering these, a 3T efficiency approaching the 4T efficiency is found, showing that 3T operation is efficient, and an outlook on fully integrated high-efficiency 3T and 2T tandem cells is given.

Analysis of polarized photoluminescence emission of ordered III–V semiconductor quaternary alloys

Energy Technology Data Exchange (ETDEWEB)

Prutskij, Tatiana, E-mail: tatiana.prutskij@correo.buap.mx [Instituto de Ciencias, BUAP, Privada 17 Norte, No 3417, Col. San Miguel Huyeotlipan, 72050 Puebla, Pue., México (Mexico); Makarov, Nykolay, E-mail: nykolay.makarov@correo.buap.mx [Instituto de Ciencias, BUAP, Privada 17 Norte, No 3417, Col. San Miguel Huyeotlipan, 72050 Puebla, Pue., México (Mexico); Attolini, Giovanni, E-mail: giovanni@imem.cnr.it [IMEM/CNR, Parco Area delle Scienze 37/A, 43010 Parma (Italy)

2016-04-15

Ternary and quaternary III–V alloys obtained by metal-organic vapor-phase epitaxy (MOVPE) grow very often with some degree of atomic ordering. Atomic ordering reduces the symmetry of the crystal lattice and thus drastically changes optical properties of the alloy. Moreover, the photoluminescence (PL) emission becomes polarized and its study helps to understand the atomic arrangement within the crystal lattice. In this work we experimentally studied the polarization of the PL emission from different crystallographic planes of several quaternary III–V semiconductor alloys grown on GaAs substrates by MOVPE. We compare the measured PL emission polarization angular patterns with those calculated with a model made for ternary alloys and discuss the limits of application of this model for quaternaries. It is found that the experimentally obtained polarization patterns are consistent with the existence of different ordering crystallographic planes for III- and for V-group atoms.

Spectroscopic identification of binary and ternary surface complexes of Np(V) on gibbsite.

Science.gov (United States)

Gückel, Katharina; Rossberg, André; Müller, Katharina; Brendler, Vinzenz; Bernhard, Gert; Foerstendorf, Harald

2013-12-17

For the first time, detailed molecular information on the Np(V) sorption species on amorphous Al(OH)3 and crystalline gibbsite was obtained by in situ time-resolved Attenuated Total Reflection Fourier-Transform Infrared (ATR FT-IR) and Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy. The results consistently demonstrate the formation of mononuclear inner sphere complexes of the NpO2(+) ion irrespective of the prevailing atmospheric condition. The impact of the presence of atmospheric equivalent added carbonate on the speciation in solution and on the surfaces becomes evident from vibrational data. While the 1:1 aqueous carbonato species (NpO2CO3(-)) was found to become predominant in the circumneutral pH range, it is most likely that this species is sorbed onto the gibbsite surface as a ternary inner sphere surface complex where the NpO2(+) moiety is directly coordinated to the functional groups of the gibbsite's surface. These findings are corroborated by results obtained from EXAFS spectroscopy providing further evidence for a bidentate coordination of the Np(V) ion on amorphous Al(OH)3. The identification of the Np(V) surface species on gibbsite constitutes a basic finding for a comprehensive description of the dissemination of neptunium in groundwater systems.

Fe-Cr-V ternary alloy-based ferritic steels for high- and low-temperature applications

International Nuclear Information System (INIS)

Rieth, M.; Materna-Morris, E.; Dudarev, S.L.; Boutard, J.-L.; Keppler, H.; Mayor, J.

2009-01-01

The phase stability of alloys and steels developed for application in nuclear fission and fusion technology is one of the decisive factors determining the potential range of operating temperatures and radiation conditions that the core elements of a power plant can tolerate. In the case of ferritic and ferritic-martensitic steels, the choice of the chemical composition is dictated by the phase diagram for binary FeCr alloys where in the 0-9% range of Cr composition the alloy remains in the solid solution phase at and below the room temperature. For Cr concentrations exceeding 9% the steels operating at relatively low temperatures are therefore expected to exhibit the formation of α' Cr-rich precipitates. These precipitates form obstacles for the propagation of dislocations, impeding plastic deformation and embrittling the material. This sets the low temperature limit for the use of of high (14% to 20%) Cr steels, which for the 20% Cr steels is at approximately 600 deg. C. On the other hand, steels containing 12% or less Cr cannot be used at temperatures exceeding ∼600 deg. C due to the occurrence of the α-γ transition (912 deg. C in pure iron and 830 deg. C in 7% Cr alloy), which weakens the steel in the high temperature limit. In this study, we investigate the physical properties of a concentrated ternary alloy system that attracted relatively little attention so far. The phase diagram of ternary Fe-Cr-V alloy shows no phase boundaries within a certain broad range of Cr and V concentrations. This makes the alloy sufficiently resistant to corrosion and suggests that steels and dispersion strengthened materials based on this alloy composition may have better strength and stability at high temperatures. Experimental heats were produced on a laboratory scale by arc melting the material components to pellets, then by melting the pellets in an induction furnace and casting the melt into copper moulds. The compositions in weight percent (iron base) are 10Cr5V, 10Cr

Cacotheline as an oxidimetric reagent. Determination of Sn(II), Cu(I), Ti(III), Fe(II), V(II) and V(III)

International Nuclear Information System (INIS)

Nemani Murty, K.; Yedluri Rao, P.; Geddada Chalam, K.

1982-01-01

Sn(II), Ti(III), Cu(I),Fe(II), V(III) and V(II) can be titrated potentiometrically with cacotheline in 1-4 M hydrochloric acid, 0.5-2 M hydrochloric acid, 0.5-1.5 M sulphuric acid in presence of 4 ml of 10% EDTA solution in a total volume of 50 ml, 9-10 M phosphoric acid, 4-8 M acetic acid and 3-8 M acetic acid respectively. Cacotheline can be used for the assay of tin plate and solder. The cacotheline undergoes a 2-electron reduction reaction. A cacotheline solution (0.005 M) in 0.02 M hydrochloric acid is fairly stable for several months. The conditional redox potentials of cacotheline have been determined in sulphuric, phosphoric and acetic acid medium. (Author)

Vertical group III-V nanowires on si, heterostructures, flexible arrays and fabrication

Science.gov (United States)

Wang, Deli; Soci, Cesare; Bao, Xinyu; Wei, Wei; Jing, Yi; Sun, Ke

2015-01-13

Embodiments of the invention provide a method for direct heteroepitaxial growth of vertical III-V semiconductor nanowires on a silicon substrate. The silicon substrate is etched to substantially completely remove native oxide. It is promptly placed in a reaction chamber. The substrate is heated and maintained at a growth temperature. Group III-V precursors are flowed for a growth time. Preferred embodiment vertical Group III-V nanowires on silicon have a core-shell structure, which provides a radial homojunction or heterojunction. A doped nanowire core is surrounded by a shell with complementary doping. Such can provide high optical absorption due to the long optical path in the axial direction of the vertical nanowires, while reducing considerably the distance over which carriers must diffuse before being collected in the radial direction. Alloy composition can also be varied. Radial and axial homojunctions and heterojunctions can be realized. Embodiments provide for flexible Group III-V nanowire structures. An array of Group III-V nanowire structures is embedded in polymer. A fabrication method forms the vertical nanowires on a substrate, e.g., a silicon substrate. Preferably, the nanowires are formed by the preferred methods for fabrication of Group III-V nanowires on silicon. Devices can be formed with core/shell and core/multi-shell nanowires and the devices are released from the substrate upon which the nanowires were formed to create a flexible structure that includes an array of vertical nanowires embedded in polymer.

Cleavage mechanoluminescence in elemental and III-V semiconductors

International Nuclear Information System (INIS)

Chandra, B.P.; Patel, R.P.; Gour, Anubha S.; Chandra, V.K.; Gupta, R.K.

2003-01-01

The present paper reports the theory of mechanoluminescence (ML) produced during cleavage of elemental and III-V semiconductors. It seems that the formation of crack-induced localized states is responsible for the ML excitation produced during the cleavage of elemental and III-V semiconductors. According to this mechanism, as the atoms are drawn away from each other in an advancing crack tip, the decreasing wave function overlap across the crack may result in localized states which is associated with increasing electron energy. If the energy of these localized states approach that of the conduction band, transition to the conduction band via tunnelling would be possible, creating minority carriers, and consequently the electron-hole recombination may give rise to mechanoluminescence. When an elemental or III-V semiconductor is cleaved, initially the ML intensity increases with time, attains a peak value I m at the time t m corresponding to completion of the cleavage of the semiconductor, and then it decreases following power law decay. Expressions are derived for the ML intensity I m corresponding to the peak of the ML intensity versus time curve and for the total ML intensity I T . It is shown that both I m and I T should increase directly with the area of the newly created surfaces of the crystals. From the measurements of the ML intensity, the velocity of crack propagation in material can be determined by using the relation v=H/t m

Structure and luminescent property of complexes of aryl carboxylic acid-functionalized polystyrene with Eu(III) and Tb(III) ions.

Science.gov (United States)

Gao, Baojiao; Shi, Nan; Qiao, Zongwen

2015-11-05

Via polymer reactions, naphthoic acid (NA) and benzoic acid (BA) were bonded onto the side chains of polystyrene (PS), respectively, and two aryl carboxylic acid-functionalized polystyrenes, PSNA and PSBA, were obtained. Using PSNA and PSBA as macromolecule ligands and Eu(3+) and Tb(3+) ions as central ions, various luminescent binary polymer-rare earth complexes were prepared. At the same time, with 1,10-phenanthroline (Phen) and 4,4'-bipyridine (Bipy) as small-molecule co-ligands, various ternary polymer-rare earth complexes were also prepared. On the basis of characterizing PSNA, PSBA and complexes, the relationship between structure and luminescent property for these prepared complexes were mainly investigated. The study results show that the macromolecule ligands PSNA and PSBA, or the bonded NA and BA ligands, can strongly sensitize the fluorescence emissions of Eu(3+) ion or Tb(3+) ion, but the sensitization effect is strongly dependent on the structure of the ligands and the property of the central ions, namely it is strongly dependent on the matching degree of energy levels. The fluorescence emission of the binary complex PS-(NA)3-Eu(III) is stronger than that PS-(BA)3-Eu(III), indicating ligand NA has stronger sensitization action for Eu(3+) ion than ligand BA; the binary complex PS-(BA)3-Tb(III) emit strong characteristic fluorescence of Tb(3+) ion, displaying that ligand BA can strongly sensitize Tb(3+) ion, whereas the binary complex PS-(NA)3-Tb(III) nearly does not emit the characteristic fluorescence of Tb(3+) ion, showing that ligand NA does not sensitize Tb(3+) ion. The fluorescence intensity of the ternary complexes is much stronger than that of the binary complexes in the same series. Copyright © 2015 Elsevier B.V. All rights reserved.

Experimental Investigation of the 1073 K (800 °C) Isothermal Section of the Al-V-Zr Ternary System

Science.gov (United States)

Zhu, Yude; Ouyang, Xuemei; Yin, Fucheng; Zhao, Manxiu; Lou, Jia

2018-03-01

This work is focused on an experimental investigation of the phase equilibria of the Al-V-Zr system at 1073 K (800 °C). The phase equilibria were analyzed using scanning electron microscopy (SEM) coupled with energy-dispersive spectrometry and X-ray diffraction. The results confirmed the presence of twelve three-phase regions and one ternary compound, Τ, which contains 10.0 to 16.5 at. pct Zr, 52.8 to 55.2 at. pct Al, and 29.3 to 36.3 at. pct V. The T phase can be in equilibrium with Al8V5, Al3Zr, Al2Zr, and α-V. The T phase belongs to the tetragonal crystal system with confirmed lattice parameters of a = 0.658531 nm and c = 0.517334 nm. The Al2Zr phase region is extraordinarily large and can be in equilibrium with all the compounds in the Al-Zr and V-Zr systems, with the exception of the AlZr phase.

Theoretical modeling of a new structure of III-V tandem solar cells by ...

African Journals Online (AJOL)

junction solar cell is theoretically investigated by optimizing the thickness of GaAs and GaInPandusing a new optical model to separate the junction between the two solar cell in order to solve problems of tunnel junction and difficulties of fabrication.

Caractérisations de matériaux et tests de composants des cellules solaires à base des nitrures des éléments III-V

OpenAIRE

Gorge , Vanessa

2012-01-01

Among III-V nitrides, the InGaN material has intensively been studied since the year 2000 for photovoltaic applications, in particular for multi-junction solar cells, thanks to its large tunable band gap covering almost the entire solar spectrum. Then, it will be possible to reach high efficiency and low cost. However, one of the problems of InGaN material is the absence of lattice-matched substrate leading to high defect density which limits device performances. We have thus studied the feas...

Sources of type III solar microwave bursts

Directory of Open Access Journals (Sweden)

Zhdanov D.A.

2016-06-01

Full Text Available Microwave fine structures allow us to study plasma evolution in an energy release region. The Siberian Solar Radio Telescope (SSRT is a unique instrument designed to examine fine structures at 5.7 GHz. A complex analysis of data from RATAN-600, 4–8 GHz spectropolarimeter, and SSRT, simultaneously with EUV data, made it possible to localize sources of III type microwave bursts in August 10, 2011 event within the entire frequency band of burst occurrence, as well as to determine the most probable region of primary energy release. To localize sources of III type bursts from RATAN-600 data, an original method for data processing has been worked out. At 5.7 GHz, the source of bursts was determined along two coordinates, whereas at 4.5, 4.7, 4.9, 5.1, 5.3, 5.5, and 6.0 GHz, their locations were identified along one coordinate. The size of the burst source at 5.1 GHz was found to be maximum as compared to those at other frequencies.

Efficient Implementation of Ternary SDM Filters using State-of-the-Art FPGA

Directory of Open Access Journals (Sweden)

Tayabuddin Memon

2011-04-01

Full Text Available We present the analysis of a ternary FIR filter at varying OSR (Over Sampling Ratios. The sigma delta modulated ternary filter impulse responses obtained using Matlab at varying OSRs show that each doubling of OSR results in an increase of 10dB in the stopband attenuation. BT-FIR (Balanced Ternary FIR Filters at varying OSRs have been implemented in VHDL using an efficient adder tree organization to gather the partial products. Filters in both pipelined and non-pipelined modes were synthesized on a small number of representative commercial FPGA (Field Programmable Gate Arrays devices. Both the filter taps and binary inputs use 2\\'s complement format. The synthesis results show the tradeoffs between hardware area and performance at varying OSRs. In pipelined mode, a 6MHz video stream can easily be handled at an OSR of 64, while occupying less than 8% of a Stratix-III device.

Microstructure of III-N semiconductors related to their applications in optoelectronics

Science.gov (United States)

Leszczynski, M.; Czernetzki, R.; Sarzynski, M.; Krysko, M.; Targowski, G.; Prystawko, P.; Bockowski, M.; Grzegory, I.; Suski, T.; Domagala, J.; Porowski, S.

2005-03-01

There has been more than a decade since Shuji Nakamura from Japanese company Nichia constructed the first blue LED based on structure of (AlGaIn)N semiconductor and eight years since he made the first blue laser diode (LD). This work gives a survey on the current technological status with green/blue/violet/UV optoelectronics based on III-N semiconductors in relation with their microstructure. The following devices are presented: i) Low-power green and blue LEDs, ii) High-power LEDs targeting solid-state white lighting, iii) Low-power violet LDs for high definition DVD market, iv) High-power violet LDs, v) UV LEDs. The discussion will be focused on three main technological problems related to the microstructure of (AlGaIn)N layers in emitters based on III-N semiconductors: i) high density of dislocations in epitaxial layers of GaN on foreign substrates (sapphire, SiC, GaAs), ii), presence of strains, iii) atom segregation in ternary and quaternary compounds.

III-V quantum light source and cavity-QED on silicon.

Science.gov (United States)

Luxmoore, I J; Toro, R; Del Pozo-Zamudio, O; Wasley, N A; Chekhovich, E A; Sanchez, A M; Beanland, R; Fox, A M; Skolnick, M S; Liu, H Y; Tartakovskii, A I

2013-01-01

Non-classical light sources offer a myriad of possibilities in both fundamental science and commercial applications. Single photons are the most robust carriers of quantum information and can be exploited for linear optics quantum information processing. Scale-up requires miniaturisation of the waveguide circuit and multiple single photon sources. Silicon photonics, driven by the incentive of optical interconnects is a highly promising platform for the passive optical components, but integrated light sources are limited by silicon's indirect band-gap. III-V semiconductor quantum-dots, on the other hand, are proven quantum emitters. Here we demonstrate single-photon emission from quantum-dots coupled to photonic crystal nanocavities fabricated from III-V material grown directly on silicon substrates. The high quality of the III-V material and photonic structures is emphasized by observation of the strong-coupling regime. This work opens-up the advantages of silicon photonics to the integration and scale-up of solid-state quantum optical systems.

Thermal oxidation of III-V compounds

International Nuclear Information System (INIS)

Monteiro, O.R.; Evans, J.W.

1988-01-01

The thermal oxidation of two important III-V compound semiconductor materials, namely GaAs and InP, has been studied between 300 and 600 0 C. In-situ TEM, cross-sectional TEM (XTEM) and SIMS analyses were used to characterize the reaction products. The first technique allows us to access the reactions at the very moment they are occurring. XTEM provides a clearer picture of the distribution of phases in the oxidized samples. SIMS gives us information on the dopant redistribution after oxidation as well as enrichment of group V element at the oxide semiconductor interface. Based on those results, the reaction products were characterized and reaction mechanisms proposed

Compounds of type Ba/sub 2/Bsup(III)Ossup(V)O/sub 6/

Energy Technology Data Exchange (ETDEWEB)

Treiber, U; Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

1981-07-01

The black perovskites of type Ba/sub 2/Bsup(III)Ossup(V)O/sub 6/ crystallize cubic (Bsup(III) = Pr, Nd, Sm-Lu, Y) and rhombohedral (Bsup(III) = La) respectively; the cell volumina decrease linearily with (rsub(B)sup(III))/sup 3/. Intensity calculations on powder data for Ba/sub 2/YOsO/sub 6/ (space group Fm3m-Osub(h)/sup 5/) and Ba/sub 2/LaOsO/sub 6/ (space group R-3m-Dsub(3d)/sup 5/) gave the intensity related R'values of 4.6% and 5.0% respectively. The results of the vibrational spectroscopic investigations are reported in common with the bond orders, M-O distances and mean amplitudes and compared with the corresponding values of the series Ba/sub 2/Bsup(III)Irsup(V)O/sub 6/ and Ba/sub 2/Bsup(III)Rusup(V)O/sub 6/.

Synthesis and characterization of (Ni{sub 1−x}Co{sub x})Se{sub 2} based ternary selenides as electrocatalyst for triiodide reduction in dye-sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Theerthagiri, J.; Senthil, R.A. [Solar Energy Lab, Department of Chemistry, Thiruvalluvar University, Vellore 632115 (India); Buraidah, M.H. [Centre for Ionics University of Malaya, Department of Physics, University of Malaya, Kuala Lumpur 50603 (Malaysia); Raghavender, M. [Department of Physics, Yogi Vemana University, Kadapa 516003, Andhra Pradesh (India); Madhavan, J., E-mail: jagan.madhavan@gmail.com [Solar Energy Lab, Department of Chemistry, Thiruvalluvar University, Vellore 632115 (India); Arof, A.K. [Centre for Ionics University of Malaya, Department of Physics, University of Malaya, Kuala Lumpur 50603 (Malaysia)

2016-06-15

Ternary metal selenides of (Ni{sub 1−x}Co{sub x})Se{sub 2} with 0≤x≤1 were synthesized by using one-step hydrothermal reduction route. The synthesized metal selenides were utilized as an efficient, low-cost platinum free counter electrode for dye-sensitized solar cells. The cyclic voltammetry and electrochemical impedance spectroscopy studies revealed that the Ni{sub 0.5}Co{sub 0.5}Se{sub 2} counter electrode exhibited higher electrocatalytic activity and lower charge transfer resistance at the counter electrode/electrolyte interface than the other compositions for reduction of triiodide to iodide. Ternary selenides of Ni{sub 0.5}Co{sub 0.5}Se{sub 2} offer a synergistic effect to the electrocatalytic activity for the reduction of triiodide that might be due to an increase in active catalytic sites and small charge transfer resistance. The DSSC with Ni{sub 0.5}Co{sub 0.5}Se{sub 2} counter electrode achieved a high power conversion efficiency of 6.02%, which is comparable with that of conventional platinum counter electrode (6.11%). This present investigation demonstrates the potential application of Ni{sub 0.5}Co{sub 0.5}Se{sub 2} as counter electrode in dye-sensitized solar cells.

Binary and ternary fission yields induced by 12C and 20Ne ions on 238U targets

International Nuclear Information System (INIS)

Otto, R.J.

1974-01-01

Evidence for ternary fission of 250 Cf* and 258 No* compound nuclei has been found. Relative cross section data for nuclides with masses between 24 Na and 161 Tb have been determined for 12 C bombardments of natural uranium at laboratory energies of 122 MeV, 113 MeV and 105 MeV. Relative cross section data for 8 nuclides between 24 Na and 66 Ni were sought for 20 Ne bombardments of natural uranium at 150 MeV laboratory energies. The binary fission fragment mass distribution for 238 U( 12 C,f) was determined by analysis of fission fragment recoil collection foils using radiochemical techniques and high resolution gamma ray spectroscopy. The results indicated the existence of a ternary fission branch similar to mass distributions obtained for He induced fission of Th, U, and Pu nuclei at intermediate energies. Comparison of the data with He induced ternary fission data obtained previously in this laboratory indicated an increase in the ternary fission probability with increasing Z 2 /A of the compound nucleus and with excitation energy. A shift of the binary-ternary fission product intersection point to lower mass numbers with increasing Z 2 /A and excitation energy of the compound nucleus was also observed. (Diss. Abstr. Int., B)

Ternary fission

Indian Academy of Sciences (India)

the energy minimization of all possible ternary breakups of a heavy radioactive nucleus. Further, within the TCM we have analysed the competition between different geometries as well as different positioning of the fragments. Also, an attempt was made to calculate the mass distribution of ternary fission process within the ...

Interpreting Interfacial Structure in Cross-Sectional STM Images of III-V Semiconductor Heterostructures

National Research Council Canada - National Science Library

Nosho, B. Z; Barvosa-Carter, W; Yang, M. J; Bennett, B. R; Whitman, L. J

2000-01-01

...) can be used for the study of III-V heterostructure interfaces. The interpretation of interfacial structure in XSTM images is impeded by the fact that only every other III or V plane as grown on the (001...

The extraction behaviour of As(III) and As(V) in APDC-CCl4 system

International Nuclear Information System (INIS)

Yang Ruiying; Zhu Xuping

1997-01-01

The extraction and back-extraction behaviour of As(III) and As(V) in APDC-CCl 4 system have been studied by using 76 As trace technique. As(III) can be extracted quantitatively by APDC-CCl 4 system at pH = 1-3. As(V) can be extracted after being reduced to As(III) by Na 2 S 2 O 3 . Water with high pH value can be used for back-extraction. The method can be applied in the separation of inorganic As(III) and As(V) in water quality inspection

Titanium nitride as an electrocatalyst for V(II)/V(III) redox couples in all-vanadium redox flow batteries

International Nuclear Information System (INIS)

Yang, Chunmei; Wang, Haining; Lu, Shanfu; Wu, Chunxiao; Liu, Yiyang; Tan, Qinglong; Liang, Dawei; Xiang, Yan

2015-01-01

Titanium nitride nanoparticles (TiN NPs) are proposed as a novel catalyst towards the V(II)/V(III) redox pair for the negative electrode in vanadium redox flow batteries (VRFB). Electrochemical properties of TiN NPs were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results show that TiN NPs demonstrate better electrochemical activity and reversibility for the processes of V(II)/V(III) redox couples as compared with the graphite NPs. TiN NPs facilitate the charge transfer in the V(II)/V(III) redox reaction. Performance of a VRFB using a TiN NPs coated carbon paper as a negative electrode is much higher than that of a VRFB with a raw carbon paper electrode. The columbic efficiency (CE), the voltage efficiency (VE) and the energy efficiency (EE) of the VRFB single cell at charge-discharge current density of 30 mA/cm 2 are 91.74%, 89.11% and 81.74%, respectively. During a 50 charge-discharge cycles test, the CE values of VRFB with TiN NPs consistently remain higher than 90%.

Ternary systems

International Nuclear Information System (INIS)

Kagan, D.N.; Hubberstey, P.; Barker, M.G.

1985-01-01

The paper reviews the experimental and theoretical studies carried out on multicomponent alkali metal systems. Solid-liquid phase equilibria studies are mainly concerned with the systems Na-K-Rb and Na-K-Cs, and data on the liquidus temperatures in these systems are presented. The thermodynamic properties of the ternary Na-K-Cs eutectic system have been determined experimentally, and the enthalpy, heat capacity and excess functions of the alloy are given. An analysis of calculational methods used in determining thermodynamic functions of ternary liquid metals systems is described. Finally, data are tabulated for the density, compressibility, saturated vapour pressure, viscosity and thermal conductivity of the ternary Na-K-Cs eutectic system. (UK)

An evaporation-based model of thermal neutron induced ternary fission of plutonium

International Nuclear Information System (INIS)

Lestone, J.P.

2008-01-01

Ternary fission probabilities for thermal neutron induced fission of plutonium are analyzed within the framework of an evaporation-based model where the complexity of time-varying potentials, associated with the neck collapse, are included in a simplistic fashion. If the nuclear temperature at scission and the fission-neck-collapse time are assumed to be ~ 1.2 MeV and ~ 10 -22 s, respectively, then calculated relative probabilities of ternary-fission light-charged-particle emission follow the trends seen in the experimental data. The ability of this model to reproduce ternary fission probabilities spanning seven orders of magnitude for a wide range of light-particle charges and masses implies that ternary fission is caused by the coupling of an evaporation-like process with the rapid re-arrangement of the nuclear fluid following scission. (author)

Fast optical in situ spectroscopy in III-V MOVPE

Energy Technology Data Exchange (ETDEWEB)

Kaspari, C.

2007-09-29

This work describes the application of optical in situ measurement techniques (reflectance anisotropy spectroscopy, RAS, and spectroscopic ellipsometry, SE) to processes that are important for the growth of III-V semiconductors like GaAs, InP, InAs and GaP in metal-organic vapour phase epitaxy (MOVPE). Special emphasis is placed on the determination of the free carrier concentration (doping level) and the study of the thermal desorption properties of III-V oxides. A large part of this work is concerned with the development and the construction of a multichannel RAS setup that allows the recording of RAS spectra within fractions of a second. On the basis of benchmark measurements it was shown that the spectral resolution is sufficiently accurate for application in epitaxy. To demonstrate the recording of spectra with high temporal resolution, RAS monolayer oscillations during growth of GaAs were studied and it was shown that the surface changes periodically between a relatively smooth morphology with adsorbed methyl groups (type III) and a stepped, gallium-rich surface (type II). Furthermore the non-reversible process of growing InAs quantum dots on GaAs was studied. It was shown that the multichannel RAS is capable of detecting the 2D-3D transition as well as the following morphological change of the surface at high temporal resolution. For the measurement of the doping level, the relationship between the doping-induced internal electric field and the anisotropy of the sample was studied. To understand the effect of the so-called doping oscillations, a theoretical model was developed. For the investigation of the thermal desorption of the III-V oxides in MOVPE, a number of test series were realised. It was also found that the formation of the reconstructed surface is finished a considerable time after the SE transient indicates stable conditions (no further reduction of the oxide layer). The activation energy for oxide desorption from InAs, GaAs and InP was

Effect of ternary alloying elements on microstructure and mechanical property of Nb-Si based refractory intermetallic alloy

International Nuclear Information System (INIS)

Kim, W.Y.; Kim, H.S.; Kim, S.K.; Ra, T.Y.; Kim, M.S.

2005-01-01

Microstructure and mechanical property at room temperature and at 1773 K of Nb-Si based refractory intermetallic alloys were investigated in terms of compression and fracture toughness test. Mo and V were chosen as ternary alloying elements because of their high melting points, atomic sizes smaller than Nb. Both ternary alloying elements were found to have a significant role in modifying the microstructure from dispersed structure to eutectic-like structure in Nb solid solution/Nb 5 Si 3 intermetallic composites. The 0.2% offset yield strength at room temperature increased with increasing content of ternary elements in Nb solid solution and volume fraction of Nb 5 Si 3 . At 1773 K, Mo addition has a positive role in increasing the yield strength. On the other hand, V addition has a role in decreasing the yield strength. The fracture toughness of ternary alloys was superior to binary alloys. Details will be discussed in correlation with ternary alloying, volume fraction of constituent phase, and the microstructure. (orig.)

The I-V Measurement System for Solar Cells Based on MCU

International Nuclear Information System (INIS)

Chen Fengxiang; Ai Yu; Wang Jiafu; Wang Lisheng

2011-01-01

In this paper, an I-V measurement system for solar cells based on Single-chip Microcomputer (MCU) is presented. According to the test principles of solar cells, this measurement system mainly comprises of two parts-data collecting, data processing and displaying. The MCU mainly used as to acquire data, then the collecting results is sent to the computer by serial port. The I-V measurement results of our test system are shown in the human-computer interaction interface based on our hardware circuit. By comparing the test results of our I-V tester and the results of other commercial I-V tester, we found errors for most parameters are less than 5%, which shows our I-V test result is reliable. Because the MCU can be applied in many fields, this I-V measurement system offers a simple prototype for portable I-V tester for solar cells.

The I-V Measurement System for Solar Cells Based on MCU

Energy Technology Data Exchange (ETDEWEB)

Chen Fengxiang; Ai Yu; Wang Jiafu; Wang Lisheng, E-mail: phonixchen79@yahoo.com.cn [Department of physics science and technology, Wuhan University of Technology, Wuhan city, Hubei Province, 430070 (China)

2011-02-01

In this paper, an I-V measurement system for solar cells based on Single-chip Microcomputer (MCU) is presented. According to the test principles of solar cells, this measurement system mainly comprises of two parts-data collecting, data processing and displaying. The MCU mainly used as to acquire data, then the collecting results is sent to the computer by serial port. The I-V measurement results of our test system are shown in the human-computer interaction interface based on our hardware circuit. By comparing the test results of our I-V tester and the results of other commercial I-V tester, we found errors for most parameters are less than 5%, which shows our I-V test result is reliable. Because the MCU can be applied in many fields, this I-V measurement system offers a simple prototype for portable I-V tester for solar cells.

Effect of metal ion Fe(III on the performance of chlorophyll as photosensitizers on dye sensitized solar cell

Directory of Open Access Journals (Sweden)

Harsasi Setyawati

Full Text Available The energy crisis is a major problem facing the world today and will need a renewable energy source that is environmentally friendly; one of these is the dye sensitized solar cell (DSSC. DSSC is photochemical electric cell that can convert solar energy into electrical energy. This research aims to study the characteristics of chlorophyll compounds with the addition of metal ions Fe(III and to determine the effect of Fe(III on the performance of chlorophyll as a photosensitizer in the DSSC. The formation of complex compounds of Fe(III-chlorophyll is shown by the phenomenon of metal ligand charge transfer (MLCT at a wavelength of 263.00 nm and absorption transition d-d at 745.00 nm. Fourier transform infrared characterization of the binding of Fe-O complex compounds appears at 486.06 cm−1. The complex compound of Fe(III-chlorophyll has a magnetic moment value of 9.62 Bohr Magneton (BM. The existence of ion Fe(III in chlorophyll can improve the performance of chlorophyll as a dye sensitizer with a maximum current of 4.00 mA/cm2, maximum voltage of 0.18 volts and efficiency values of 1.35%. Keywords: Fe(III-chlorophyll, Dye sensitized solar cell, Metal ligand charge transfer, Photosensitizer

Synthesis, investigation and spectroscopic characterization of piroxicam ternary complexes of Fe(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) with glycine and DL-phenylalanine

Science.gov (United States)

Mohamed, Gehad G.; El-Gamel, Nadia E. A.

2004-11-01

The ternary piroxicam (Pir; 4-hydroxy-2-methyl- N-(2-pyridyl)-2H-1,2-benzothiazine-3-carboxamide 1,1-dioxide) complexes of Fe(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) with various amino acids (AA) such as glycine (Gly) or DL-phenylalanine (PhA) were prepared and characterized by elemental analyses, molar conductance, IR, UV-Vis, magnetic moment, diffuse reflectance and X-ray powder diffraction. The UV-Vis spectra of Pir and the effect of metal chelation on the different interligand transitions are discussed in detailed manner. IR and UV-Vis spectra confirm that Pir behaves as a neutral bidentate ligand coordinated to the metal ions via the pyridine- N and carbonyl group of the amide moiety. Gly molecule acted as a uninegatively monodentate ligand and coordinate to the metal ions through its carboxylic group, in addition PhA acted as a uninegatively bidentate ligand and coordinate to the metal ions through its carboxylic and amino groups. All the chelates have octahedral geometrical structures while Cu(II)- and Zn(II)-ternary chelates with PhA have square planar geometrical structures. The molar conductance data reveal that most of these chelates are non electrolytes, while Fe(III)-Pir-Gly, Co(II)-, Ni(II)-, Cu(II)- and Zn(II)-Pir-PhA cheletes were 1:1 electrolytes. X-ray powder diffraction is used as a new tool to estimate the crystallinity of chelates as well as to elucidate their geometrical structures.

He and Be ternary spontaneous fission of sup 2 sup 5 sup 2 Cf

CERN Document Server

Hwang, J K; Ramayya, A V; Hamilton, J H

2002-01-01

Ternary and binary fission studies of sup 2 sup 5 sup 2 Cf have been carried out by using the Gammasphere detector array with light charged particle (LCD) detectors. The relative sup 4 He and sup 5 He ternary fission yields were determined. The kinetic energies of the sup 5 He and sup 4 He ternary particles were found to be approximately 11 and 16 MeV, respectively. The sup 5 He particles contribute 10-20 % to the total observed alpha ternary yield. The data indicate that in nuclei with octupole deformations the population for the negative parity bands might be enhanced in the alpha ternary fission. >From LCP-gamma double gated spectra, neutron multiplicity distributions for alpha ternary fission pairs were measured. The average neutron multiplicity decreases about 0.7 AMU in going from the binary to alpha ternary fission in the approximately same mass splittings (104-146). From the analysis of the gamma-gamma matrix gated on the sup 1 sup 0 Be particles, the two fragment pairs of sup 1 sup 3 sup 8 Xe - sup 1...

Thorium coprecipitation method for spectrophotometric determination of arsenic (III) and arsenic (V) in groundwaters

International Nuclear Information System (INIS)

Tamari, Yuzo; Yamamoto, Nobuki; Tsuji, Haruo; Kusaka, Yuzuru

1989-01-01

A new coprecipitation method for the spectrophotometry of arsenic (III) and arsenic (V) in groundwater has been developed. Arsenic (III) and arsenic (V) were coprecipitated with thorium (IV) hydroxide from 1000ml of groundwater at pH9. The precipitate was centrifuged and then dissolved with hydrochloric acid. Arsenic (III) was spectrophotometrically determined by the usual silver diethylditiocarbamate (Ag-DDTC) method after generating the arsenic to arsine with sodium tetrahydroborate under masking the thorium with EDTA-NaF at pH6. From another portion of the same groundwater, both arsenic (III) and arsenic (V) were determined by the Ag-DDTC method after reducing all the arsenic to arsine with sodium tetrahydroborate at pH less than 1 in the presence of the EDTA-NaF. The concentration of arsenic (V) was obtained by subtracting that of arsenic (III) from the total for arsenic. (author)

Quantitative STEM on indium containing group III-V semiconductor nanostructures

International Nuclear Information System (INIS)

Mehrtens, Thorsten

2013-01-01

In the framework of this thesis. a method for compositional analysis of semiconductor nanostructures is applied on technologically relevant group III-V alloys. It is based on a quantitative comparison between intensities of experimentally acquired High-Angle Annular Dark Field Scanning Tansmission Electron Microscopy (HAADF-STEM) images and simulated intensities from multislice calculations in the frozen lattice approach. The demonstrated method allows determination of specimen thickness and material composition on subnanometer scale. Since quantitative HAADF-STEM is still a very young technique, its applicability has only been proven for a few materials, yet. Thus, the main goal of this thesis is the simulation of suitable reference datasets for different ternary semiconducting alloys and to test their reliability by complementary analysis. A total of three different semiconducting materials are thereby analyzed (InGaN, InGaAs and InAlN) that have all in common that they contain indium. The main focus of this work lies on InGaN which is due to its bandgap particularly suitable for the fabrication of optoelectronic devices operating in the visible spectrum of the light. In the first part of the presented results, the quality of ultra-thin TEM-specimens prepared by techniques involving ion milling at high energies is optimized. This is done by an additional ion milling step where the impinging ions possess an energy of only 400 eV. It is found that the preparation induced amorphous surface layer that occurs during ion milling can be drastically reduced below 1 nm. The second part concentrates on results obtained on InGaN. Here, different simulations in the frozen lattice approach are carried out under certain conditions. These simulations either include or do not include thermal diffuse scattering and/or static atomic displacement to demonstrate their influence on the amount of intensity measured in the experiment. As the consideration of thermal diffuse scattering

Solar cells based on InP/GaP/Si structure

Science.gov (United States)

Kvitsiani, O.; Laperashvil, D.; Laperashvili, T.; Mikelashvili, V.

2016-10-01

Solar cells (SCs) based on III-V semiconductors are reviewed. Presented work emphases on the Solar Cells containing Quantum Dots (QDs) for next-generation photovoltaics. In this work the method of fabrication of InP QDs on III-V semiconductors is investigated. The original method of electrochemical deposition of metals: indium (In), gallium (Ga) and of alloys (InGa) on the surface of gallium phosphide (GaP), and mechanism of formation of InP QDs on GaP surface is presented. The possibilities of application of InP/GaP/Si structure as SC are discussed, and the challenges arising is also considered.

All ternary permutation constraint satisfaction problems parameterized above average have kernels with quadratic numbers of variables

DEFF Research Database (Denmark)

Gutin, Gregory; Van Iersel, Leo; Mnich, Matthias

2010-01-01

A ternary Permutation-CSP is specified by a subset Π of the symmetric group S3. An instance of such a problem consists of a set of variables V and a multiset of constraints, which are ordered triples of distinct variables of V. The objective is to find a linear ordering α of V that maximizes...... the number of triples whose rearrangement (under α) follows a permutation in Π. We prove that all ternary Permutation-CSPs parameterized above average have kernels with quadratic numbers of variables....

Long-wavelength III-V/silicon photonic integrated circuits

NARCIS (Netherlands)

Roelkens, G.C.; Kuyken, B.; Leo, F.; Hattasan, N.; Ryckeboer, E.M.P.; Muneeb, M.; Hu, C.L.; Malik, A.; Hens, Z.; Baets, R.G.F.; Shimura, Y.; Gencarelli, F.; Vincent, B.; Loo, van de R.; Verheyen, P.A.; Lepage, G.; Campenhout, van J.; Cerutti, L.; Rodriquez, J.B.; Tournie, E.; Chen, X; Nedeljkovic, G.; Mashanovich, G.; Liu, X.; Green, W.S.

2013-01-01

We review our work in the field of short-wave infrared and mid-infrared photonic integrated circuits for applications in spectroscopic sensing systems. Passive silicon waveguide circuits, GeSn photodetectors, the integration of III-V and IV-VI semiconductors on these circuits, and silicon nonlinear

Ternary Fission of U235 by Resonance Neutrons

International Nuclear Information System (INIS)

Kvitek, I.; Popov, Ju.P.; Rjabov, Ju.V.

1965-01-01

Recently a number of papers have appeared indicating considerable variations in the ratio of the ternary-fission cross-section to the binary-fission cross-section of U 235 on transition from one neutron resonance to another. However, such variations have not been discovered in U 233 and Pu 239 . The paper reports investigations of the ternary fission of U 235 by neutrons with an energy of 0.1 to 30 eV. Unlike other investigators of the ternary fission of U 235 , we identified the ternary-fission event by the coincidence of one of the fission fragments with a light long-range particle. This made it passible to separate ternary fissions from the possible contribution of the (n, α)reaction. The measurements were performed at the fast pulsed reactor of the Joint Institute for Nuclear Research by the time-of-flight method. A flight length of 100 m was used, giving a resolution of 0.6 μs/m. Gas scintillation counters filled with xenon at a pressure of 2 atm were used to record the fission fragments and the light long-range particle. A layer of enriched U 235 ∼2 mg/cm 2 thick and ∼300 cm 2 in area was applied to an aluminium foil 20-fim thick. The scintillations from the fission fragments were recorded in the gas volume on one side of the foil and those from the light long-range particles in that on the other. In order to assess the background (e.g . coincidences of the pulse from a fragment with that from a fission gamma quantum or a proton from the (n, p) reaction in the aluminium foil), a measurement was carried out in which the volume recording the long-range particle was shielded with a supplementary aluminium filter 1-mm thick. The results obtained indicate the absence of the considerable variations in the ratio between the ternary-and binary- fission cross-sections for U 235 that have been noted by other authors. Measurements showed no irregularity in the ratio of the cross-sections in the energy range 0.1 to 0.2 eV. The paper discusses the possible effect of

Ternary fission of spontaneously fissile uranium isomers excited by neutrons

International Nuclear Information System (INIS)

Makarenko, V.E.; Molchanov, Y.D.; Otroshchenko, G.A.; Yan'kov, G.B.

1989-01-01

Spontaneously fissile isomers (SFI) of uranium were excited in the reactions 236,238 U(n,n') at an average neutron energy 4.5 MeV. A pulsed electrostatic accelerator and time analysis of the fission events were used. Fission fragments were detected by the scintillation method, and long-range particles from fission were detected by an ionization method. The relative probability of fission of nuclei through a spontaneously fissile isomeric state was measured: (1.30±0.01)·10 -4 ( 236 U) and (1.48±0.02)·10 -4 ( 238 U). Half-lives of the isomers were determined: 121±2 nsec (the SFI 236 U) and 267±13 nsec (the SFI 238 U). In study of the ternary fission of spontaneously fissile isotopes of uranium it was established that the probability of the process amounts to one ternary fission per 163±44 binary fissions of the SFI 236 U and one ternary fission per 49±14 binary fissions of the SFI 238 U. The substantial increase of the probability of ternary fission of SFI of uranium in comparison with the case of ternary fission of nuclei which are not in an isomeric state may be related to a special nucleon configuration of the fissile isomers of uranium

High efficiency thin-film solar cells for space applications: challenges and opportunities

NARCIS (Netherlands)

Leest, R.H. van

2017-01-01

In theory high efficiency thin-film III-V solar cells obtained by the epitaxial lift-off (ELO) technique offer excellent characteristics for application in space solar panels. The thesis describes several studies that investigate the space compatibility of the thin-film solar cell design developed

Effect on strength of ternary alloying additions in L12 intermetallics

International Nuclear Information System (INIS)

Wu Yuanpang.

1991-01-01

The thermodynamic properties of {111} antiphase boundaries (APBs) as well as the site preference of ternary additions in an A 3 B intermetallic with L1 2 structure are studied, using a thermodynamic model. A survey of the results from a variety of ternary alloying additions to Ni 3 Al has shown that there is a conflict in the actual role which solid solution strengthening plays in the athermal increment of yield strength. For instance, a good quantitative agreement with linear concentration law is observed only in alloys with stoichiometric compositions but not in the general case of non-stoichiometric alloys. In the light of the possibility that micro-segregation could explain the experimental discrepancy, the author extends the binary solid solution strengthening theory to the ternary system in an L1 2 structure for the four real systems of Ni-Al-Si, Ni-Al-Ti, Ni-Al-Hf, and Ni-Al-V. It is found that ternary site preference plays an important role in the ternary solid solution strengthening theory with L1 2 structure. Good quantitative agreement was found between the calculated and experimentally measured strength for both stoichiometric and nonstoichiometric alloys

Subsurface dimerization in III-V semiconductor (001) surfaces

DEFF Research Database (Denmark)

Kumpf, C.; Marks, L.D.; Ellis, D.

2001-01-01

We present the atomic structure of the c(8 X 2) reconstructions of InSb-, InAs-, and GaAs-(001) surfaces as determined by surface x-ray diffraction using direct methods. Contrary to common belief, group III dimers are not prominent on the surface, instead subsurface dimerization of group m atoms ...... takes place in the second bilayer, accompanied by a major rearrangement of the surface atoms above the dimers to form linear arrays. By varying the occupancies of four surface sites the (001)-c(8 X 2) reconstructions of III-V semiconductors can be described in a unified model....

First-principles study of ternary bcc alloys using special quasi-random structures

International Nuclear Information System (INIS)

Jiang Chao

2009-01-01

Using a combination of exhaustive enumeration and Monte Carlo simulated annealing, we have developed special quasi-random structures (SQSs) for ternary body-centered cubic (bcc) alloys with compositions of A 1 B 1 C 1 , A 2 B 1 C 1 , A 6 B 1 C 1 and A 2 B 3 C 3 , respectively. The structures possess local pair and multisite correlation functions that closely mimic those of the random bcc alloy. We employed the SQSs to predict the mixing enthalpies, nearest neighbor bond length distributions and electronic density of states of bcc Mo-Nb-Ta and Mo-Nb-V solid solutions. Our convergence tests indicate that even small-sized SQSs can give reliable results. Based on the SQS energetics, the predicting powers of the existing empirical ternary extrapolation models were assessed. The present results suggest that it is important to take into account the ternary interaction parameter in order to accurately describe the thermodynamic behaviors of ternary alloys. The proposed SQSs are quite general and can be applied to other ternary bcc alloys.

Determination of stability constants of iron(III and chromium(III-nitrilotriacetate-methyl cysteine mixed complexes by electrophoretic technique

Directory of Open Access Journals (Sweden)

Brij Bhushan Tewari

2004-06-01

Full Text Available The stability constants of Fe(III and Cr(III with methyl cysteine and nitrilotriacetate (NTA were determined by paper electrophoretic technique. Beside binary ternary complexes have also been studied, in which nitrilotriacetate and methyl cysteine acts as primary and secondary ligand, respectively. The stability constants of mixed ligand complexes metal (M-nitrilotriacetate-methyl cysteine have been found to be 5.72 plus or minus 0.09 and 5.54 plus or minus 0.11 (log K values for Fe(III and Cr(III complexes, respectively, at 35 oC and ionic strength 0.1 M.

30 CFR 57.22202 - Main fans (I-A, I-B, I-C, II-A, III, V-A, and V-B mines).

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Main fans (I-A, I-B, I-C, II-A, III, V-A, and V... Main fans (I-A, I-B, I-C, II-A, III, V-A, and V-B mines). (a) Main fans shall be— (1) Installed on the... mines, provided with an automatic signal device to give an alarm when the fan stops. The signal device...

Excess molar volumes of the ternary system {methylcyclohexane (1)+cyclohexane (2)+n-alkanes (3)} at T=298.15 K

International Nuclear Information System (INIS)

Iloukhani, Hossein; Rezaei-Sameti, Mahdi

2005-01-01

Densities were experimentally determined in the whole range of composition at T=298.15 K for the ternary system {methylcyclohexane (1)+cyclohexane (2)+n-alkanes (3)} and for the seven corresponding binary systems. The n-alkanes include n-hexane, n-heptane, and n-octane. Excess molar volumes, V E , were calculated for the binaries and ternaries systems. The V 123 E data are positive over the entire range of composition for the systems {methylcyclohexane (1)+cyclohexane (2)+n-heptane (3) or n-octane (3)} at three fixed compositions (f m =X 1 /X 2 ). For the system {methylcyclohexane (1)+cyclohexane (2)+n-hexane (3)}, the V E values showed positive for f m =0.3 and negative for f m =3. The V E data exhibit, an inversion in sign in the mixture containing f m =1 for later ternary system. Several empirical expressions are used to predict and correlate the ternary excess molar volumes from experimental results on the constituted binaries and analyzed to gain insight about liquid mixture interactions

Cr-doped III-V nitrides: Potential candidates for spintronics

KAUST Repository

Amin, Bin

2011-02-19

Studies of Cr-doped III-V nitrides, dilute magnetic alloys in the zincblende crystal structure, are presented. The objective of the work is to investigate half-metallicity in Al 0.75Cr 0.25N, Ga 0.75Cr 0.25N, and In 0.75Cr 0.25N for their possible application in spin-based electronic devices. The calculated spin-polarized band structures, electronic properties, and magnetic properties of these compounds reveal that Al 0.75Cr 0.25N and Ga 0.75Cr 0.25N are half-metallic dilute magnetic semiconductors while In 0.75Cr 0.25N is metallic in nature. The present theoretical predictions provide evidence that some Cr-doped III-V nitrides can be used in spintronics devices. © 2011 TMS.

Cr-doped III-V nitrides: Potential candidates for spintronics

KAUST Repository

Amin, Bin; Arif, Suneela K.; Ahmad, Iftikhar; Maqbool, Muhammad; Ahmad, Roshan; Goumri-Said, Souraya; Prisbrey, Keith A.

2011-01-01

Studies of Cr-doped III-V nitrides, dilute magnetic alloys in the zincblende crystal structure, are presented. The objective of the work is to investigate half-metallicity in Al 0.75Cr 0.25N, Ga 0.75Cr 0.25N, and In 0.75Cr 0.25N for their possible application in spin-based electronic devices. The calculated spin-polarized band structures, electronic properties, and magnetic properties of these compounds reveal that Al 0.75Cr 0.25N and Ga 0.75Cr 0.25N are half-metallic dilute magnetic semiconductors while In 0.75Cr 0.25N is metallic in nature. The present theoretical predictions provide evidence that some Cr-doped III-V nitrides can be used in spintronics devices. © 2011 TMS.

Half-Heusler compounds with a 1 eV (1.7 eV) direct band gap, lattice-matched to GaAs (Si), for solar cell application: A first-principles study

KAUST Repository

Belmiloud, N.

2016-01-10

A systematic theoretical study of the structural and electronic properties of new half-Heusler compounds is performed to find the appropriate target key physical parameters for photovoltaic application. As a result, five ternary half-Heusler compounds ScAgC, YCuC, CaZnC, NaAgO, and LiCuS are studied by density functional theory for potential applications in multi-junction solar cells. The calculated formation enthalpies indicate that these materials are thermodynamically stable. Using state-of-the-art modified Becke-Johnson exchange potential approximation, we find a direct band gap close to 1eV (∼1.88eV) for ScAgC, YCuC, CaZnC, NaAgO (LiCuS) being quasi-lattice matched to GaAs (Si). In addition, the band offsets between half-Heusler compounds and GaAs (Si) and their consequences for heterostructures are derived using the modified Tersoff method for the branch-point energy. Furthermore, the elastic constants and phonon dispersion curves are calculated. They indicate the respective mechanical and dynamical stability of these half-Heusler compounds. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Microbial reduction of [Co(III)-EDTA]⁻ by Bacillus licheniformis SPB-2 strain isolated from a solar salt pan.

Science.gov (United States)

Paraneeiswaran, Arunachalam; Shukla, Sudhir K; Prashanth, K; Rao, T Subba

2015-01-01

Naturally stressed habitats are known to be repositories for novel microorganisms with potential bioremediation applications. In this study, we isolated a [Co(III)-EDTA](-) reducing bacterium Bacillus licheniformis SPB-2 from a solar salt pan that is exposed to constant cycles of hydration and desiccation in nature. [Co(III)-EDTA](-) generated during nuclear waste management process is difficult to remove from the waste due to its high stability and solubility. It is reduced form i.e. [Co(II)-EDTA](2-) is less stable though it is toxic. This study showed that B. licheniformis SPB-2 reduced 1mM [Co(III)-EDTA](-) in 14 days when grown in a batch mode. However, subsequent cycles showed an increase in the reduction activity, which was observed up to four cycles. Interestingly, the present study also showed that [Co(III)-EDTA](-) acted as an inducer for B. licheniformis SPB-2 spore germination. Vegetative cells germinated from the spores were found to be involved in [Co(III)-EDTA](-) reduction. More detailed investigations showed that after [Co(III)-EDTA](-) reduction, i.e. [Co(II)-EDTA](2-) complex was removed by B. licheniformis SPB-2 from the bulk liquid by adsorption phenomenon. The bacterium showed a D10 value (radiation dose required to kill 90% cells) of ∼250 Gray (Gy), which signifies the potential use of B. licheniformis SPB-2 for bioremediation of moderately active nuclear waste. Copyright © 2014 Elsevier B.V. All rights reserved.

Preliminary temperature Accelerated Life Test (ALT) on III-V commercial concentrator triple-junction solar cells

OpenAIRE

Espinet González, Pilar; Algora del Valle, Carlos; Orlando Carrillo, Vincenzo; Nuñez Mendoza, Neftali; Vázquez López, Manuel; Bautista Villares, Jesus; Xiugang, He; Barrutia Poncela, Laura; Rey-Stolle Prado, Ignacio; Araki, Kenji

2012-01-01

A quantitative temperature accelerated life test on sixty GaInP/GaInAs/Ge triple-junction commercial concentrator solar cells is being carried out. The final objective of this experiment is to evaluate the reliability, warranty period, and failure mechanism of high concentration solar cells in a moderate period of time. The acceleration of the degradation is realized by subjecting the solar cells at temperatures markedly higher than the nominal working temperature under a concentrator Three e...

Novel low fluence combination laser treatment of solar lentigines in type III Asian skin

Directory of Open Access Journals (Sweden)

Brian Wei Cheng Anthony Tian

2015-01-01

Full Text Available Objective: To demonstrate a novel low fluence combination laser technique [Erbium-doped yttrium aluminum garnet (Erb:YAG and neodymium-doped yttrium aluminum garnet (Nd:YAG] to effectively treat solar lentigines in type III Asian skin in a single session. Design: A prospective study. Setting: A Singapore-based clinic. Participants: Five patients (all females were enrolled into the study. The ages ranged 35-60 years; all patients had Fitzpatrick skin type III. Measurements: Photographs were taken at baseline and at 1-month follow-up. These were reviewed by two independent physicians who were blinded to the study. Changes in pigment severity were assessed by a 5-point scale (1: Aggravation of pigment, 2: No change, 3: 25-50% improvement, 4: 51-75% improvement, and 5: 76-100% improvement. Results: All patients received a single treatment session. At 1-month follow-up, a reduction in pigment was observed in all patients. Both physicians′ reports were independently agreeable. All patients scored 5, having >90% improvement in pigment severity. No hypopigmentation, postinflammatory hyperpigmentation (PIH, or recurrence was seen. Conclusion: Low fluence combination laser is effective and safe for clearance of solar lentigines in type III Asian skin.

Sequential and simultaneous adsorption of Sb(III) and Sb(V) on ferrihydrite: Implications for oxidation and competition.

Science.gov (United States)

Qi, Pengfei; Pichler, Thomas

2016-02-01

Antimony (Sb) is a naturally occurring element of growing environmental concern whose toxicity, adsorption behavior and other chemical properties are similar to that of arsenic (As). However, less is known about Sb compared to As. Individual and simultaneous adsorption experiments with Sb(III) and Sb(V) were conducted in batch mode with focus on the Sb speciation of the remaining liquid phase during individual Sb(III) adsorption experiments. The simultaneous adsorption and oxidation of Sb(III) was confirmed by the appearance of Sb(V) in the solution at varying Fe/Sb ratios (500, 100 and 8) and varying pH values (3.8, 7 and 9). This newly formed Sb(V) was subsequently removed from solution at a Fe/Sb ratio of 500 or at a pH of 3.8. However, more or less only Sb(V) was observed in the liquid phase at the end of the experiments at lower Fe/Sb ratios and higher pH, indicating that competition took place between the newly formed Sb(V) and Sb(III), and that Sb(III) outcompeted Sb(V). This was independently confirmed by simultaneous adsorption experiments of Sb(III) and Sb(V) in binary systems. Under such conditions, the presence of Sb(V) had no influence on the adsorption of Sb(III) while Sb(V) adsorption was significantly inhibited by Sb(III) over a wide pH range (4-10). Thus, in the presence of ferrihydrite and under redox conditions, which allow the presence of both Sb species, Sb(V) should be the dominant species in aquatic environments, since Sb(III) is adsorbed preferentially and at the same time oxidized to Sb(V). Copyright © 2015 Elsevier Ltd. All rights reserved.

Integration, gap formation, and sharpening of III-V heterostructure nanowires by selective etching

DEFF Research Database (Denmark)

Kallesoe, C.; Mølhave, Kristian; Larsen, K. F.

2010-01-01

Epitaxial growth of heterostructure nanowires allows for the definition of narrow sections with specific semiconductor composition. The authors demonstrate how postgrowth engineering of III-V heterostructure nanowires using selective etching can form gaps, sharpening of tips, and thin sections...... lithography is used for deposition of catalyst particles on trench sidewalls and the lateral growth of III-V nanowires is achieved from such catalysts. The selectivity of a bromine-based etch on gallium arsenide segments in gallium phosphide nanowires is examined, using a hydrochloride etch to remove the III...

Binary and ternary systems

International Nuclear Information System (INIS)

Petrov, D.A.

1986-01-01

Conditions for thermodynamical equilibrium in binary and ternary systems are considered. Main types of binary and ternary system phase diagrams are sequently constructed on the basis of general regularities on the character of transition from one equilibria to others. New statements on equilibrium line direction in the diagram triple points and their isothermal cross sections are developed. New represenations on equilibria in case of monovariant curve minimum and maximum on three-phase equilibrium formation in ternary system are introduced

Interplanetary scattering of fast solar electrons deduced from type III bursts observed at low frequencies

International Nuclear Information System (INIS)

Alvarez, H.; Lin, R.P.

1976-01-01

Observations of low frequency solar type III radio bursts and the associated fast solar electrons show that the total path length travelled by the particles between the Sun and the Earth is significantly greater than the length of the smooth Archimedean spiral trajectory followed by the centroid of the type III exciter (Alvarez et al., 1975). Here it is assumed that the ratio of electron path length and the spiral length increases approximately as rsup(n), where r is heliocentric distance, and then compute the radio bursts arrival time at 1 AU for different values of n. A comparison with the radio observations indicates that the best fit occurs for n=1.5+-1.0. These results are interpreted in terms of the variation of electron scattering with heliocentric distance. (Auth.)

True ternary fission in 310126X

International Nuclear Information System (INIS)

Banupriya, B.; Vijayaraghavan, K.R.; Balasubramaniam, M.

2015-01-01

All possible combinations are minimized by the two dimensional minimization process and minimized with respect to neutron numbers and proton numbers of the fragments. Potential energy is low and Q - value is high at true ternary fission region. It shows that true ternary mode is the dominant mode in the ternary fission of superheavy nuclei. Also, the results show that the fragments with neutron magic numbers are the dominant one in the ternary fission of superheavy nuclei whereas the fragments with proton magic numbers are the dominant one in the ternary fission of heavy nuclei

Transferable tight binding model for strained group IV and III-V heterostructures

Science.gov (United States)

Tan, Yaohua; Povolotskyi, Micheal; Kubis, Tillmann; Boykin, Timothy; Klimeck, Gerhard

Modern semiconductor devices have reached critical device dimensions in the range of several nanometers. For reliable prediction of device performance, it is critical to have a numerical efficient model that are transferable to material interfaces. In this work, we present an empirical tight binding (ETB) model with transferable parameters for strained IV and III-V group semiconductors. The ETB model is numerically highly efficient as it make use of an orthogonal sp3d5s* basis set with nearest neighbor inter-atomic interactions. The ETB parameters are generated from HSE06 hybrid functional calculations. Band structures of strained group IV and III-V materials by ETB model are in good agreement with corresponding HSE06 calculations. Furthermore, the ETB model is applied to strained superlattices which consist of group IV and III-V elements. The ETB model turns out to be transferable to nano-scale hetero-structure. The ETB band structures agree with the corresponding HSE06 results in the whole Brillouin zone. The ETB band gaps of superlattices with common cations or common anions have discrepancies within 0.05eV.

Enhanced fluorescence of Tb(III), Dy(III) perchlorate by salicylic acid in bis(benzoylmethyl) sulfoxide complexes and luminescence mechanism

International Nuclear Information System (INIS)

Li Wenxian; Zheng Yushan; Sun Xiaojun; Chai Wenjuan; Ren Tie; Shi Xiaoyan

2010-01-01

Two novel ternary rare earth perchlorate complexes had been synthesized by using bis(benzoylmethyl) sulfoxide as first ligand (L=C 6 H 5 COCH 2 SOCH 2 COC 6 H 5 ), salicylic acid as second ligand (L ' =C 6 H 4 OHCOO - ). The compounds were characterized by elemental analysis, TG-DSC and molar conductivities in DMF solution. The composition was suggested as [REL 5 L'](ClO 4 ) 2 .nH 2 O (RE=Tb, Dy; n=6, 8 ). Based on IR, 1 HNMR and UV spectra, it showed that the first ligand, bis(benzoylmethyl) sulfoxide (L), bonded with Tb(III), Dy(III) ions by the oxygen atom of sulfinyl group. The second ligand, salicylic acid group (L'), not only bonded with RE(III) ions by one oxygen atom of carboxyl group but also bonded with RE(III) ions by oxygen atom of phenolic hydroxyl group. In bis(benzoylmethyl) sulfoxide system, fluorescent spectra of the complexes showed that the luminescence of Tb(III), Dy(III) ions was enhanced by the second ligand salicylic acid. The ternary complexes had stronger fluorescence than the binary ones where only bis(benzoylmethyl) sulfoxide acted as ligand. Phosphorescent spectra of the two ligands indicated that the coordination of salicylic acid resulted in the matching extent increasing between the triplet state of ligand and excited state of the rare earths. The relationship between fluorescence lifetime and fluorescence intensity was also discussed.

III-V nanoelectronics and related surface/interface issues

International Nuclear Information System (INIS)

Hasegawa, Hideki

2003-01-01

The conventional logic gate architecture is not suitable for high-density integration of quantum devices which are non-robust and extremely structure- and charge-sensitive. In this paper, our novel hexagonal binary-decision-diagram (BDD) quantum circuit approach for III-V nanoelectronics is reviewed and related critical surface/interface issues for high-density integration are discussed. First, the basic concept and actual implementation method of our approach are explained, giving examples of novel BDD quantum integrated circuits where nanowire networks are controlled by nanoscale Schottky wrap gates. For high-density integration, growth of embedded sub-10 nm III-V quantum wire networks by selective molecular beam epitaxy (MBE) on patterned substrates is described, including effects of atomic hydrogen irradiation and kinetic control of wire width. The key processing issue lies in understanding and control of nanostructure surfaces/interfaces. Behavior of nanoscale Schottky gates, recent scanning tunneling microscopy (STM)/scanning tunneling spectroscopy (STS) studies of surface states, and successful removal of surface states by MBE-grown silicon interface control layer are discussed

Solar flares, coronal mass ejections and solar energetic particle event characteristics

Science.gov (United States)

Papaioannou, Athanasios; Sandberg, Ingmar; Anastasiadis, Anastasios; Kouloumvakos, Athanasios; Georgoulis, Manolis K.; Tziotziou, Kostas; Tsiropoula, Georgia; Jiggens, Piers; Hilgers, Alain

2016-12-01

A new catalogue of 314 solar energetic particle (SEP) events extending over a large time span from 1984 to 2013 has been compiled. The properties as well as the associations of these SEP events with their parent solar sources have been thoroughly examined. The properties of the events include the proton peak integral flux and the fluence for energies above 10, 30, 60 and 100 MeV. The associated solar events were parametrized by solar flare (SF) and coronal mass ejection (CME) characteristics, as well as related radio emissions. In particular, for SFs: the soft X-ray (SXR) peak flux, the SXR fluence, the heliographic location, the rise time and the duration were exploited; for CMEs the plane-of-sky velocity as well as the angular width were utilized. For radio emissions, type III, II and IV radio bursts were identified. Furthermore, we utilized element abundances of Fe and O. We found evidence that most of the SEP events in our catalogue do not conform to a simple two-class paradigm, with the 73% of them exhibiting both type III and type II radio bursts, and that a continuum of event properties is present. Although, the so-called hybrid or mixed events are found to be present in our catalogue, it was not possible to attribute each SEP event to a mixed/hybrid sub-category. Moreover, it appears that the start of the type III burst most often precedes the maximum of the SF and thus falls within the impulsive phase of the associated SF. At the same time, type III bursts take place within ≈5.22 min, on average, in advance from the time of maximum of the derivative of the SXR flux (Neupert effect). We further performed a statistical analysis and a mapping of the logarithm of the proton peak flux at E > 10 MeV, on different pairs of the parent solar source characteristics. This revealed correlations in 3-D space and demonstrated that the gradual SEP events that stem from the central part of the visible solar disk constitute a significant radiation risk. The velocity of

First-principles study on half-metallic ferromagnetic properties of Zn1- x V x Se ternary alloys

Science.gov (United States)

Khatta, Swati; Tripathi, S. K.; Prakash, Satya

2017-09-01

The spin-polarised density functional theory along with self-consistent plane-wave pseudopotential is used to investigate the half-metallic ferromagnetic properties of ternary alloys Zn1- x V x Se. The generalized gradient approximation is used for exchange-correlation potential. The equilibrium lattice constants, bulk modulus, and its derivatives are calculated. The calculated spin-polarised energy-band structures reveal that these alloys are half-metallic for x = 0.375 and 0.50 and nearly half-metallic for other values of x. The estimated direct and indirect bandgaps may be useful for the magneto-optical absorption experiments. It is found that there is strong Zn 4s, Se 4p, and V 3d orbital hybridization in the conduction bands of both the spins, while Se 4p and V 3d orbital hybridization predominates in the valence bands of both the spins. The s, p-d, and p-d orbital hybridization reduces the local magnetic moment of V atoms and small local magnetic moments are produced on Zn and Se atoms which get coupled with V atoms in ferromagnetic and antiferromagnetic phases, respectively. The conduction and valence-band-edge splittings and exchange constants predict the ferromagnetism in these alloys. The conduction band-impurity (s and p-d) exchange interaction is more significant for ferromagnetism in these alloys than the valence band-impurity (p-d) exchange interaction.

Treatment of As(V) and As(III) by electrocoagulation using Al and Fe electrode.

Science.gov (United States)

Kuan, W H; Hu, C Y; Chiang, M C

2009-01-01

A batch electrocoagulation (EC) process with bipolar electrode and potentiodynamic polarization tests with monopolar systems were investigated as methods to explore the effects of electrode materials and initial solution pH on the As(V) and As(III) removal. The results displayed that the system with Al electrode has higher reaction rate during the initial period from 0 to 25 minutes than that of Fe electrode for alkaline condition. The pH increased with the EC time because the As(V) and As(III) removal by either co-precipitation or adsorption resulted in that the OH positions in Al-hydroxide or Fe-hydroxide were substituted by As(V) and As(III). The pH in Fe electrode system elevate higher than that in Al electrode because the As(V) removal substitutes more OH position in Fe-hydroxide than that in Al-hydroxide. EC system with Fe electrode can successfully remove the As(III) but system with Al electrode cannot because As(III) can strongly bind to the surface of Fe-hydroxide with forming inner-sphere species but weakly adsorb to the Al-hydroxide surface with forming outer-sphere species. The acidic solution can destroy the deposited hydroxide passive film then allow the metallic ions liberate into the solution, therefore, the acidic initial solution can enhance the As(V) and As(III) removal. The over potential calculation and potentiodynamic polarization tests reveal that the Fe electrode systems possess higher over potential and pitting potential than that of Al electrode system due to the fast hydrolysis of and the occurrence of Fe-hydroxide passive film.

Reflectance properties of one-dimensional metal-dielectric ternary photonic crystal

Energy Technology Data Exchange (ETDEWEB)

Pandey, G. N., E-mail: gnpandey2009@gmail.com [Department of Physics, Amity Institute of Applied Sciences, AmityUniversity, Noida (U.P.) (India); Kumar, Narendra [Department of Physics (CASH), Modi University of Science and Technology, Lakshmangarh, Sikar, Rajsthan (India); Thapa, Khem B. [Department of Physics, U I E T, ChhatrapatiShahu Ji Maharaj University, Kanpur- (UP) (India); Ojha, S. P. [Department of Physics IIT, Banaras Hindu University (India)

2016-05-06

Metallic photonic crystal has a very important application in absorption enhancement in solar cells. It has been found that an ultra-thin metallic layer becomes transparent due to internal scattering of light through the each interface of the dielectric and metal surfaces. The metal has absorption due to their surface plasmon and the plasmon has important parameters for changing optical properties of the metal. We consider ternary metallic-dielectric photonic crystal (MDPC) for having large probabilities to change the optical properties of the MDPC and the photonic crystals may be changed by changing dimensionality, symmetry, lattice parameters, Filling fraction and effective refractive index refractive index contrast. In this present communication, we try to show that the photonic band gap in ternary metal-dielectric photonic crystal can be significantly enlarged when air dielectric constant is considered. All the theoretical analyses are made based on the transfer matrix method together with the Drude model of metal.

A review of recent progress in heterogeneous silicon tandem solar cells

Science.gov (United States)

Yamaguchi, Masafumi; Lee, Kan-Hua; Araki, Kenji; Kojima, Nobuaki

2018-04-01

Silicon solar cells are the most established solar cell technology and are expected to dominate the market in the near future. As state-of-the-art silicon solar cells are approaching the Shockley-Queisser limit, stacking silicon solar cells with other photovoltaic materials to form multi-junction devices is an obvious pathway to further raise the efficiency. However, many challenges stand in the way of fully realizing the potential of silicon tandem solar cells because heterogeneously integrating silicon with other materials often degrades their qualities. Recently, above or near 30% silicon tandem solar cell has been demonstrated, showing the promise of achieving high-efficiency and low-cost solar cells via silicon tandem. This paper reviews the recent progress of integrating solar cell with other mainstream solar cell materials. The first part of this review focuses on the integration of silicon with III-V semiconductor solar cells, which is a long-researched topic since the emergence of III-V semiconductors. We will describe the main approaches—heteroepitaxy, wafer bonding and mechanical stacking—as well as other novel approaches. The second part introduces the integration of silicon with polycrystalline thin-film solar cells, mainly perovskites on silicon solar cells because of its rapid progress recently. We will also use an analytical model to compare the material qualities of different types of silicon tandem solar cells and project their practical efficiency limits.

Green options for anti-corrosion of high strength concrete incorporating ternary pozzolan materials

Directory of Open Access Journals (Sweden)

Chen Yuan-Yuan

2017-01-01

Full Text Available This paper applied the densified mixture design algorithm(DMDA method by incorporating ternary pozzolans (fly ash, slag and silica fume; mix I and mix II to design high strength concrete (HSC mixtures with w/cm ratios from 0.24 to 0.30. Concrete without pozzolans was used as a control group (mix III, w/c from 0.24 to 0.30, and silica fume (5% was added as a substitute for part of the cement and set as mix IV. Experiments performed compressive strength, four-point resistance meter to measure the conductivity, and rapid chloride ion penetrability tests (ASTM C1202 were assessed the anti-corrosion. The life cycle inventory of LEED suggested by the PCA indicated the green options for cementitious materials. Results showed that mix I and II indicated cement used, CO2 reduction, raw materials and energy consumption all decreased more 50% than mix III, and mix IV was 5% less. The compressive strength and anti-corrosion levels showed that mix I and II were better than mix III and IV, and with ternary pozzolans could enhance the long-term durability (92 days due to a resistivity greater 20 KΩ-cm and a charge passed lower than 2000 Coulombs. HSC with an appropriate design could reduce the carbon footprint and improve the durability.

Thermal analysis of a solar collector consisting of V cavities for water heating; Analise termica de um coletor solar composto de cavidades V para aquecimento de agua

Energy Technology Data Exchange (ETDEWEB)

Moreira, Michel Fabio de Souza

2009-03-15

The solar water heating is carried through, in Brazil, by means of solar heaters compound for collectors flat plate of the type plate-and-pipes, devices that operate in stationary position and they do not require tracking of the sun. A compound collector for some formed V-trough concentrators can be an alternative to the conventional solar collectors flat plate. This compound collector for V-trough is considered, each one, for side-walls which are specularly reflecting surfaces associates in V (equivalent to a triangular gutter). Next to the vertex to each V-trough concentrators an absorber tube is fixed, for flow of the fluid to be heated. Interconnection of the absorbers tubes forms a similar tubular network existing in solar collectors of the type the plate and pipe. V-trough concentrators with the absorbers tubes are made use in series in the interior a prismatic box, which have one of its faces consisting by a glass covering and directed toward incidence of the solar radiation. An analysis of thermal performance of these devices operating stationary and without tracking of the sun is researched. A mathematical model for the computational simulation of the optical and thermal performance of these concentrative devices is elaborated, whose implementation was carried through software EES (Engineering Equation Solver). The efficiency optics of V-trough concentrators with cylindrical absorbers is calculated from the adaptation of the methodology used for Fraidenraich (1994), proposal for Hollands (1971) for V-trough cavities with plain absorbers. The thermal analysis of the considered collector was based on the applied methodology the CPC for Hsieh (1981) and Leao (1989). Relative results to the thermal performance of V-trough concentrators suggest that these configurations are not competitive, technique and economically, with the conventional plain collectors. Although some geometric configurations presented next thermal efficiencies to the conventional plain

Adsorption Characteristics of Different Adsorbents and Iron(III Salt for Removing As(V from Water

Directory of Open Access Journals (Sweden)

Josip Ćurko

2016-01-01

Full Text Available The aim of this study is to determine the adsorption performance of three types of adsorbents for removal of As(V from water: Bayoxide® E33 (granular iron(III oxide, Titansorb® (granular titanium oxide and a suspension of precipitated iron(III hydroxide. Results of As(V adsorption stoichiometry of two commercial adsorbents and precipitated iron(III hydroxide in tap and demineralized water were fitted to Freundlich and Langmuir adsorption isotherm equations, from which adsorption constants and adsorption capacity were calculated. The separation factor RL for the three adsorbents ranged from 0.04 to 0.61, indicating effective adsorption. Precipitated iron(III hydroxide had the greatest, while Titansorb had the lowest capacity to adsorb As(V. Comparison of adsorption from tap or demineralized water showed that Bayoxide and precipitated iron(III hydroxide had higher adsorption capacity in demineralized water, whereas Titansorb showed a slightly higher capacity in tap water. These results provide mechanistic insights into how commonly used adsorbents remove As(V from water.

Production of fine structures in type III solar radio bursts due to turbulent density profiles

International Nuclear Information System (INIS)

Loi, Shyeh Tjing; Cairns, Iver H.; Li, Bo

2014-01-01

Magnetic reconnection events in the corona release energetic electron beams along open field lines, and the beams generate radio emission at multiples of the electron plasma frequency f p to produce type III solar radio bursts. Type III bursts often exhibit irregularities in the form of flux modulations with frequency and/or local temporal advances and delays, and a type IIIb burst represents the extreme case where a type III burst is fragmented into a chain of narrowband features called striae. Remote and in situ spacecraft measurements have shown that density turbulence is ubiquitous in the corona and solar wind, and often exhibits a Kolmogorov power spectrum. In this work, we numerically investigate the effects of one-dimensional macroscopic density turbulence (along the beam direction) on the behavior of type III bursts, and find that this turbulence produces stria-like fine structures in the dynamic spectra of both f p and 2 f p radiation. Spectral and temporal fine structures in the predicted type III emission are produced by variations in the scattering path lengths and group speeds of radio emission, and in the locations and sizes of emitting volumes. Moderate turbulence levels yield flux enhancements with much broader half-power bandwidths in f p than 2 f p emission, possibly explaining the often observed type IIIb-III harmonic pairs as being where intensifications in 2 f p radiation are not resolved observationally. Larger turbulence levels producing trough-peak regions in the plasma density profile may lead to broader, resolvable intensifications in 2 f p radiation, which may account for the type IIIb-IIIb pairs that are sometimes observed.

Quadrupole interaction in ternary chalcopyrite semiconductors experiments and theory

CERN Document Server

Dietrich, M; Degering, D; Deicher, M; Kortus, J; Magerle, R; Möller, A; Samokhvalov, V; Unterricker, S; Vianden, R

2000-01-01

Electric field gradients have been measured at substitutional lattice sites in ternary semiconductors using perturbed gamma - gamma angular correlation spectroscopy. The experimental results for A/sup I/B/sup III/C/sub 2//sup VI/ chalcopyrite structure compounds and Square Operator A/sup II/B/sub 2//sup III/C/sub 4//sup VI/ defect chalcopyrites are compared with ab-initio calculations. The latter were carried out with the WIEN code that uses the full potential linearized augmented plane wave method within a density functional theory. The agreement between experiment and theory is in most cases very good. Furthermore, the anion displacements in AgGaX/sub 2/- compounds (X: S, Se, Te) have been determined theoretically by determining the minimum of the total energy of the electrons in an elementary cell. (20 refs).

Monte-Carlo simulation of crystallographical pore growth in III-V-semiconductors

International Nuclear Information System (INIS)

Leisner, Malte; Carstensen, Juergen; Foell, Helmut

2011-01-01

The growth of crystallographical pores in III-V-semiconductors can be understood in the framework of a simple model, which is based on the assumption that the branching of pores is proportional to the current density at the pore tips. The stochastic nature of this model allows its implementation into a three-dimensional Monte-Carlo-simulation of pore growth. The simulation is able to reproduce the experimentally observed crysto pore structures in III-V-semiconductors in full quantitative detail. The different branching probabilities for different semiconductors, as well as doping levels, can be deduced from the specific passivation behavior of the semiconductor-electrolyte-interface at the pore tips.

Structure and spectroscopic study of aqueous Fe(III)-As(V) complexes using UV-Vis, XAS and DFT-TDDFT.

Science.gov (United States)

Chai, Liyuan; Yang, Jinqin; Zhang, Ning; Wu, Pin-Jiun; Li, Qingzhu; Wang, Qingwei; Liu, Hui; Yi, Haibo

2017-09-01

Aqueous complexes between ferric (Fe(III)) and arsenate (As(V)) are indispensable for understanding the mobility of arsenic (As) in Fe(III)-As(V)-rich systems. In this study, aqueous Fe(III)-As(V) complexes, FeH 2 AsO 4 2+ and FeHAsO 4 + , were postulated based on the qualitative analysis of UV-Vis spectra in both Fe(III)-As(V)-HClO 4 and Fe(III)-As(V)-H 2 SO 4 systems. Subsequently, monodentate structures were evidenced by Fe K-edge EXAFS and modeled as [FeH 2 AsO 4 (H 2 O) 5 ] 2+ and [FeHAsO 4 (H 2 O) 5 ] + by DFT. The feature band at ∼280 nm was verified as electron excitation chiefly from Fe-As-bridged O atoms to d-orbital of Fe in [FeH 2 AsO 4 (H 2 O) 5 ] 2+ and [FeHAsO 4 (H 2 O) 5 ] + . The structural and spectral information of Fe(III)-As(V) complexes will enable future speciation analysis in Fe(III)-As(V)-rich system. Copyright © 2017. Published by Elsevier Ltd.

Transferable tight-binding model for strained group IV and III-V materials and heterostructures

Science.gov (United States)

Tan, Yaohua; Povolotskyi, Michael; Kubis, Tillmann; Boykin, Timothy B.; Klimeck, Gerhard

2016-07-01

It is critical to capture the effect due to strain and material interface for device level transistor modeling. We introduce a transferable s p3d5s* tight-binding model with nearest-neighbor interactions for arbitrarily strained group IV and III-V materials. The tight-binding model is parametrized with respect to hybrid functional (HSE06) calculations for varieties of strained systems. The tight-binding calculations of ultrasmall superlattices formed by group IV and group III-V materials show good agreement with the corresponding HSE06 calculations. The application of the tight-binding model to superlattices demonstrates that the transferable tight-binding model with nearest-neighbor interactions can be obtained for group IV and III-V materials.

The coupling of thermochemistry and phase diagrams for group III-V semiconductor systems. Final report

Energy Technology Data Exchange (ETDEWEB)

Anderson, T.J.

1998-07-21

The project was directed at linking the thermochemical properties of III-V compound semiconductors systems with the reported phase diagrams. The solid-liquid phase equilibrium problem was formulated and three approaches to calculating the reduced standard state chemical potential were identified and values were calculated. In addition, thermochemical values for critical properties were measured using solid state electrochemical techniques. These values, along with the standard state chemical potentials and other available thermochemical and phase diagram data, were combined with a critical assessment of selected III-V systems. This work was culminated with a comprehensive assessment of all the III-V binary systems. A novel aspect of the experimental part of this project was the demonstration of the use of a liquid encapsulate to measure component activities by a solid state emf technique in liquid III-V systems that exhibit high vapor pressures at the measurement temperature.

Description of the ternary system Cu-Ge-Te

International Nuclear Information System (INIS)

Dogguy, M.; Carcaly, C.; Rivet, J.; Flahaut, J.

1977-01-01

The Cu-Ge-Te ternary system has been studied by DTA and by crystallographic and metallographic analysis. The existence of a ternary compound Cu 2 GeTe 3 is demonstrated; this compound has a ternary incongruent melting point at 500 0 C. This ternary compound has a superstructure of a zinc blende type. The study shows the existence of five ternary eutectics. Two liquid-liquid miscibility gaps exist: the first is situated entirely in the ternary system; the second gives a monotectic region within the ternary system. (Auth.)

Generic technique to grow III-V semiconductor nanowires in a closed glass vessel

Directory of Open Access Journals (Sweden)

Kan Li

2016-06-01

Full Text Available Crystalline III-V semiconductor nanowires have great potential in fabrication of nanodevices for applications in nanoelectronics and optoelectronics, and for studies of novel physical phenomena. Sophisticated epitaxy techniques with precisely controlled growth conditions are often used to prepare high quality III-V nanowires. The growth process and cost of these experiments are therefore dedicated and very high. Here, we report a simple but generic method to synthesize III-V nanowires with high crystal quality. The technique employs a closed evacuated tube vessel with a small tube carrier containing a solid source of materials and another small tube carrier containing a growth substrate inside. The growth of nanowires is achieved after heating the closed vessel in a furnace to a preset high temperature and then cooling it down naturally to room temperature. The technique has been employed to grow InAs, GaAs, and GaSb nanowires on Si/SiO2 substrates. The as-grown nanowires are analyzed by SEM, TEM and Raman spectroscopy and the results show that the nanowires are high quality zincblende single crystals. No particular condition needs to be adjusted and controlled in the experiments. This technique provides a convenient way of synthesis of III-V semiconductor nanowires with high material quality for a wide range of applications.

Epitaxial III-V nanowires on silicon for vertical devices

NARCIS (Netherlands)

Bakkers, E.P.A.M.; Borgström, M.T.; Einden, Van Den W.; Weert, van M.H.M.; Helman, A.; Verheijen, M.A.

2006-01-01

We show the epitaxial integration of III-V semiconductor nanowires with silicon technology. The wires are grown by the Vapor-Liquid-Solid (VLS) mechanism with laser ablation as well as metal organic vapor phase epitaxy. The VLS growth enables the fabrication of complex axial and radial

Phase equilibria of the Mo-Al-Ho ternary system

Energy Technology Data Exchange (ETDEWEB)

Li, Yitai; Chen, Xiaoxian; Liu, Hao [Guangxi Univ., Nanning (China). College of Materials Science and Engineering; Guangxi Univ., Nanning (China). Guangxi Key Laboratory of Processing for Non-ferrous Metal and Featured Materials; Zhan, Yongzhong [Guangxi Univ., Nanning (China). College of Materials Science and Engineering; Guangxi Univ., Nanning (China). Guangxi Key Laboratory of Processing for Non-ferrous Metal and Featured Materials; Guangxi Univ., Nanning (China). Center of Ecological Collaborative Innovation for Aluminum Industry

2017-08-15

Investigation into the reactions and phase equilibria of transition metal elements (i.e. Mo, Zr, Cr, V and Ti), Al and rare earths is academically and industrially important for the development of both refractory alloys and lightweight high-temperature materials. In this work, the equilibria of the Mo-Al-Ho ternary system at 773 K have been determined by using X-ray powder diffraction and scanning electron microscopy equipped with energy dispersive X-ray analysis. A new ternary phase Al{sub 4}Mo{sub 2}Ho has been found and the other ternary phase Al{sub 43}Mo{sub 4}Ho{sub 6} is observed. Ten binary phases in the Al-Mo and Al-Ho systems, including Al{sub 17}Mo{sub 4} rather than Al{sub 4}Mo, have been determined to exist at 773 K. The homogeneity ranges of AlMo{sub 3} and Al{sub 8}Mo{sub 3} phase are 7.5 at.% and 1 at.%, respectively. According to the phase-disappearing method, the maximum solubility of Al in Mo is about 16 at.%.

Silicon-Based Integration of Groups III, IV, V Chemical Vapor Depositions in High-Quality Photodiodes

NARCIS (Netherlands)

Sammak, A.

2012-01-01

Heterogeneous integration of III-V semiconductors with silicon (Si) technology is an interesting approach to utilize the advantages of both high-speed photonic and electronic properties. The work presented in this thesis is initiated by this major goal of merging III-V semiconductor technology with

Investigation of itraconazole ternary amorphous solid dispersions based on povidone and Carbopol.

Science.gov (United States)

Meng, Fan; Meckel, Jordan; Zhang, Feng

2017-08-30

We investigate a ternary system that consists of itraconazole (ITZ) and two polymers: povidone K12 and Carbopol 907. The interactions between these two polymers and their effects on the properties of ternary ITZ amorphous solid dispersions (ASDs) are studied. These two polymers can form a water-insoluble complex in acidic aqueous media. The critical pH is determined to be 4.17. The weight percentage of Carbopol 907 in the interpolymer complex range from 59 to 70%, depending on the initial ratios between these two polymers in the starting solutions. This complexation is driven by a negative enthalpy change from the H-bonding between the two polymers and a positive entropy change from the freed water molecules. Due to the slow precipitation of the interpolymer complex in aqueous media, the attempt to prepare ternary ASD using solvent-controlled coprecipitation is not successful. Melt extrusion is identified to be the only viable method to prepare this ternary ASD. We find that interpolymer complex-based ASDs are physically less stable and demonstrate the poorest drug-release properties when compared to individual polymer-based binary ASDs. This study illustrates that the too strong interaction between polymers in ternary ASDs is detrimental to their performance. Copyright © 2017 Elsevier B.V. All rights reserved.

Theory of ferromagnetic (III,Mn)V semiconductors

Czech Academy of Sciences Publication Activity Database

Jungwirth, Tomáš; Sinova, J.; Mašek, Jan; Kučera, Jan; MacDonald, A. H.

2006-01-01

Roč. 78, - (2006), s. 809-859 ISSN 0034-6861 R&D Projects: GA MŠk LC510; GA ČR GA202/05/0575 Grant - others:EPSRC(GB) GR/S81407/01; U.S. Department of Energy(US) DE-FG03-02ER45958; U.S. Office of Naval research(US) OMR-N000140610122 Institutional research plan: CEZ:AV0Z10100521 Keywords : ferromagnetic semiconductors * (III,Mn)V compounds Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 33.508, year: 2006

Radiation Effects in III-V Nanowire Devices

Science.gov (United States)

2016-09-01

fabrication of an in-plane nanowire (NW) GaAs metal-oxide-semiconductor field- effect transistor (MOSFET) by focused -ion beam (FIB) etching and chemical...8725 John J. Kingman Road, MS 6201 Fort Belvoir, VA 22060-6201 T E C H N IC A L R E P O R T DTRA-TR-16-94 Radiation Effects in III-V...5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING / MONITORING AGENCY

Ternary-fragmentation-driving potential energies of 252Cf

Science.gov (United States)

Karthikraj, C.; Ren, Zhongzhou

2017-12-01

Within the framework of a simple macroscopic model, the ternary-fragmentation-driving potential energies of 252Cf are studied. In this work, all possible ternary-fragment combinations of 252Cf are generated by the use of atomic mass evaluation-2016 (AME2016) data and these combinations are minimized by using a two-dimensional minimization approach. This minimization process can be done in two ways: (i) with respect to proton numbers (Z1, Z2, Z3) and (ii) with respect to neutron numbers (N1, N2, N3) of the ternary fragments. In this paper, the driving potential energies for the ternary breakup of 252Cf are presented for both the spherical and deformed as well as the proton-minimized and neutron-minimized ternary fragments. From the proton-minimized spherical ternary fragments, we have obtained different possible ternary configurations with a minimum driving potential, in particular, the experimental expectation of Sn + Ni + Ca ternary fragmentation. However, the neutron-minimized ternary fragments exhibit a driving potential minimum in the true-ternary-fission (TTF) region as well. Further, the Q -value energy systematics of the neutron-minimized ternary fragments show larger values for the TTF fragments. From this, we have concluded that the TTF region fragments with the least driving potential and high Q values have a strong possibility in the ternary fragmentation of 252Cf. Further, the role of ground-state deformations (β2, β3, β4, and β6) in the ternary breakup of 252Cf is also studied. The deformed ternary fragmentation, which involves Z3=12 -19 fragments, possesses the driving potential minimum due to the larger oblate deformations. We also found that the ground-state deformations, particularly β2, strongly influence the driving potential energies and play a major role in determining the most probable fragment combinations in the ternary breakup of 252Cf.

Adsorção de arsênio(V pela quitosana ferro - III reticulada Asorption of arsenic (V by crosslinked iron-III-chitosan

Directory of Open Access Journals (Sweden)

Tathyane Fagundes

2008-01-01

Full Text Available The removal of As(V by a crosslinked iron(III-chitosan adsorbent was evaluated under various conditions. The adsorption capacity of CH-FeCL was around 54 mg/g of As(V. The kinetics of adsorption obeys a pseudo-first-order model with rate constants equal to 0.022, 0.028, and 0.033 min-1 at 15, 25 and 35 ºC respectively. Adsorption data were well described by the Langmuir model, although they could be modeled also by the Langmuir-Freundlich equation. The maximum adsorption capacity, calculated with the Langmuir model, was 127 mg g-1 of As(V. The inhibition by competing anions is dependant on their kind and valence.

High-Efficient Circuits for Ternary Addition

Directory of Open Access Journals (Sweden)

Reza Faghih Mirzaee

2014-01-01

Full Text Available New ternary adders, which are fundamental components of ternary addition, are presented in this paper. They are on the basis of a logic style which mostly generates binary signals. Therefore, static power dissipation reaches its minimum extent. Extensive different analyses are carried out to examine how efficient the new designs are. For instance, the ternary ripple adder constructed by the proposed ternary half and full adders consumes 2.33 μW less power than the one implemented by the previous adder cells. It is almost twice faster as well. Due to their unique superior characteristics for ternary circuitry, carbon nanotube field-effect transistors are used to form the novel circuits, which are entirely suitable for practical applications.

Implications of the Differential Toxicological Effects of III-V Ionic and Particulate Materials for Hazard Assessment of Semiconductor Slurries.

Science.gov (United States)

Jiang, Wen; Lin, Sijie; Chang, Chong Hyun; Ji, Zhaoxia; Sun, Bingbing; Wang, Xiang; Li, Ruibin; Pon, Nanetta; Xia, Tian; Nel, André E

2015-12-22

Because of tunable band gaps, high carrier mobility, and low-energy consumption rates, III-V materials are attractive for use in semiconductor wafers. However, these wafers require chemical mechanical planarization (CMP) for polishing, which leads to the generation of large quantities of hazardous waste including particulate and ionic III-V debris. Although the toxic effects of micron-sized III-V materials have been studied in vivo, no comprehensive assessment has been undertaken to elucidate the hazardous effects of submicron particulates and released III-V ionic components. Since III-V materials may contribute disproportionately to the hazard of CMP slurries, we obtained GaP, InP, GaAs, and InAs as micron- (0.2-3 μm) and nanoscale (particles for comparative studies of their cytotoxic potential in macrophage (THP-1) and lung epithelial (BEAS-2B) cell lines. We found that nanosized III-V arsenides, including GaAs and InAs, could induce significantly more cytotoxicity over a 24-72 h observation period. In contrast, GaP and InP particulates of all sizes as well as ionic GaCl3 and InCl3 were substantially less hazardous. The principal mechanism of III-V arsenide nanoparticle toxicity is dissolution and shedding of toxic As(III) and, to a lesser extent, As(V) ions. GaAs dissolves in the cell culture medium as well as in acidifying intracellular compartments, while InAs dissolves (more slowly) inside cells. Chelation of released As by 2,3-dimercapto-1-propanesulfonic acid interfered in GaAs toxicity. Collectively, these results demonstrate that III-V arsenides, GaAs and InAs nanoparticles, contribute in a major way to the toxicity of III-V materials that could appear in slurries. This finding is of importance for considering how to deal with the hazard potential of CMP slurries.

Three-dimensional Langmuir wave instabilities in type III solar radio bursts

International Nuclear Information System (INIS)

Bardwell, S.; Goldman, M.V.

1976-01-01

Assuming that type III solar radio bursts are associated with electron streams moving at about c/3, Langmuir waves should be strongly excited. We have studied all of the Langmuir-wave linear parametric instabilities excited in cylindrical symmetry by an electron-stream--driven Langmuir wave-pump propagating along the stream axis. Included in this unified homogeneous treatment are induced backscattering off ions, the oscillating two-stream instability, and a new ''stimulated modulational instability,'' previously unconsidered in this context. Near a few solar radii, the latter two deposit Langmuir wave energy into a forward-scattering cone about the stream axis. It is concluded that the linear stage of the forward-scattering instabilities involves transfer of energy to Langmuir waves which remain in resonance with the stream, and therefore probably do not prevent rapid depletion of the electron stream due to quasilinear plateau formation at these distances from the Sun

New Observations of Soft X-ray (0.5-5 keV) Solar Spectra

Science.gov (United States)

Caspi, A.; Woods, T. N.; Mason, J. P.; Jones, A. R.; Warren, H. P.

2013-12-01

The solar corona is the brightest source of X-rays in the solar system, and the X-ray emission is highly variable on many time scales. However, the actual solar soft X-ray (SXR) (0.5-5 keV) spectrum is not well known, particularly during solar quiet periods, as, with few exceptions, this energy range has not been systematically studied in many years. Previous observations include high-resolution but very narrow-band spectra from crystal spectrometers (e.g., Yohkoh/BCS), or integrated broadband irradiances from photometers (e.g., GOES/XRS, TIMED/XPS, etc.) that lack detailed spectral information. In recent years, broadband measurements with moderate energy resolution (~0.5-0.7 keV FWHM) were made by SphinX on CORONAS-Photon and SAX on MESSENGER, although they did not extend to energies below ~1 keV. We present observations of solar SXR emission obtained using new instrumentation flown on recent SDO/EVE calibration rocket underflights. The photon-counting spectrometer, a commercial Amptek X123 with a silicon drift detector and an 8 μm Be window, measures the solar disk-integrated SXR emission from ~0.5 to >10 keV with ~0.15 keV FWHM resolution and 1 s cadence. A novel imager, a pinhole X-ray camera using a cooled frame-transfer CCD (15 μm pixel pitch), Ti/Al/C filter, and 5000 line/mm Au transmission grating, images the full Sun in multiple spectral orders from ~0.1 to ~5 nm with ~10 arcsec/pixel and ~0.01 nm/pixel spatial and spectral detector scales, respectively, and 10 s cadence. These instruments are prototypes for future CubeSat missions currently being developed. We present new results of solar observations on 04 October 2013 (NASA sounding rocket 36.290). We compare with previous results from 23 June 2012 (NASA sounding rocket 36.286), during which solar activity was low and no signal was observed above ~4 keV. We compare our spectral and imaging measurements with spectra and broadband irradiances from other instruments, including SDO/EVE, GOES/XRS, TIMED

Trends in heteroepitaxy of III-Vs on silicon for photonic and photovoltaic applications

Science.gov (United States)

Lourdudoss, Sebastian; Junesand, Carl; Kataria, Himanshu; Metaferia, Wondwosen; Omanakuttan, Giriprasanth; Sun, Yan-Ting; Wang, Zhechao; Olsson, Fredrik

2017-02-01

We present and compare the existing methods of heteroepitaxy of III-Vs on silicon and their trends. We focus on the epitaxial lateral overgrowth (ELOG) method as a means of achieving good quality III-Vs on silicon. Initially conducted primarily by near-equilibrium epitaxial methods such as liquid phase epitaxy and hydride vapour phase epitaxy, nowadays ELOG is being carried out even by non-equilibrium methods such as metal organic vapour phase epitaxy. In the ELOG method, the intermediate defective seed and the mask layers still exist between the laterally grown purer III-V layer and silicon. In a modified ELOG method called corrugated epitaxial lateral overgrowth (CELOG) method, it is possible to obtain direct interface between the III-V layer and silicon. In this presentation we exemplify some recent results obtained by these techniques. We assess the potentials of these methods along with the other existing methods for realizing truly monolithic photonic integration on silicon and III-V/Si heterojunction solar cells.

High-performance III-V MOSFET with nano-stacked high-k gate dielectric and 3D fin-shaped structure.

Science.gov (United States)

Chen, Szu-Hung; Liao, Wen-Shiang; Yang, Hsin-Chia; Wang, Shea-Jue; Liaw, Yue-Gie; Wang, Hao; Gu, Haoshuang; Wang, Mu-Chun

2012-08-01

A three-dimensional (3D) fin-shaped field-effect transistor structure based on III-V metal-oxide-semiconductor field-effect transistor (MOSFET) fabrication has been demonstrated using a submicron GaAs fin as the high-mobility channel. The fin-shaped channel has a thickness-to-width ratio (TFin/WFin) equal to 1. The nano-stacked high-k Al2O3 dielectric was adopted as a gate insulator in forming a metal-oxide-semiconductor structure to suppress gate leakage. The 3D III-V MOSFET exhibits outstanding gate controllability and shows a high Ion/Ioff ratio > 105 and a low subthreshold swing of 80 mV/decade. Compared to a conventional Schottky gate metal-semiconductor field-effect transistor or planar III-V MOSFETs, the III-V MOSFET in this work exhibits a significant performance improvement and is promising for future development of high-performance n-channel devices based on III-V materials.

Ternary q-Virasoro-Witt Hom-Nambu-Lie algebras

International Nuclear Information System (INIS)

Ammar, F; Makhlouf, A; Silvestrov, S

2010-01-01

In this paper we construct ternary q-Virasoro-Witt algebras which q-deform the ternary Virasoro-Witt algebras constructed by Curtright, Fairlie and Zachos using su(1, 1) enveloping algebra techniques. The ternary Virasoro-Witt algebras constructed by Curtright, Fairlie and Zachos depend on a parameter and are not Nambu-Lie algebras for all but finitely many values of this parameter. For the parameter values for which the ternary Virasoro-Witt algebras are Nambu-Lie, the corresponding ternary q-Virasoro-Witt algebras constructed in this paper are also Hom-Nambu-Lie because they are obtained from the ternary Nambu-Lie algebras using the composition method. For other parameter values this composition method does not yield a Hom-Nambu-Lie algebra structure for q-Virasoro-Witt algebras. We show however, using a different construction, that the ternary Virasoro-Witt algebras of Curtright, Fairlie and Zachos, as well as the general ternary q-Virasoro-Witt algebras we construct, carry a structure of the ternary Hom-Nambu-Lie algebra for all values of the involved parameters.

STABILITY: AN INVESTIGATION OF AS(III)/AS(V) STABILITY IN IRON RICH DRINKING WATER MATRICES

Science.gov (United States)

Arsenic in drinking water is predominantly inorganic arsenic. The two oxidation states of inorganic arsenic are As(III)(pKa=9.3) and As(V)(pKa2=6.9). The distribution of As(III) and AS(V) in a water is dependent on the redox potential of the water. The actual distribution can ...

Ternary scandium and transition metals germanides

International Nuclear Information System (INIS)

Kotur, B.Ya.

1992-01-01

Brief review of data on phase diagram of ternary Sc-Me-Ge systems (Me-d - , f-transition element) is given. Isothermal sections at 870 and 1070 K of 17 ternary systems are plotted. Compositions and their structural characteristics are presented. Variability of crystal structure is typical for ternary scandium germanides: 70 compounds with the studied structure belong to 23 structural types. Ternary germanides isostructural to types of Sm 4 Ge 4 , ZrCrSi 2 , ZrNiAl, ScCeSi, TiNiSi U 4 Re 7 Si 6 145 compounds from 70 under investigation are mostly formed in studied systems

First-principles interatomic potentials for transition-metal aluminides. III. Extension to ternary phase diagrams

Science.gov (United States)

Widom, Mike; Al-Lehyani, Ibrahim; Moriarty, John A.

2000-08-01

Modeling structural and mechanical properties of intermetallic compounds and alloys requires detailed knowledge of their interatomic interactions. The first two papers of this series [Phys. Rev. B 56, 7905 (1997); 58, 8967 (1998)] derived first-principles interatomic potentials for transition-metal (TM) aluminides using generalized pseudopotential theory (GPT). Those papers focused on binary alloys of aluminum with first-row transition metals and assessed the ability of GPT potentials to reproduce and elucidate the alloy phase diagrams of Al-Co and Al-Ni. This paper addresses the phase diagrams of the binary alloy Al-Cu and the ternary systems Al-Co-Cu and Al-Co-Ni, using GPT pair potentials calculated in the limit of vanishing transition-metal concentration. Despite this highly simplifying approximation, we find rough agreement with the known low-temperature phase diagrams, up to 50% total TM concentration provided the Co fraction is below 25%. Full composition-dependent potentials and many-body interactions would be required to correct deficiencies at higher Co concentration. Outside this troublesome region, the experimentally determined stable and metastable phases all lie on or near the convex hull of a scatter plot of energy versus composition. We verify, qualitatively, reported solubility ranges extending binary alloys into the ternary diagram in both Al-Co-Cu and Al-Co-Ni. Finally, we reproduce previously conjectured transition-metal positions in the decagonal quasicrystal phase.

An ultrahigh vacuum, low-energy ion-assisted deposition system for III-V semiconductor film growth

Science.gov (United States)

Rohde, S.; Barnett, S. A.; Choi, C.-H.

1989-06-01

A novel ion-assisted deposition system is described in which the substrate and growing film can be bombarded with high current densities (greater than 1 mA/sq cm) of very low energy (10-200 eV) ions. The system design philosophy is similar to that used in III-V semiconductor molecular-beam epitaxy systems: the chamber is an all-metal ultrahigh vacuum system with liquid-nitrogen-cooled shrouds, Knudsen-cell evaporation sources, a sample insertion load-lock, and a 30-kV reflection high-energy electron diffraction system. III-V semiconductor film growth is achieved using evaporated group-V fluxes and group-III elemental fluxes sputtered from high-purity targets using ions extracted from a triode glow discharge. Using an In target and an As effusion cell, InAs deposition rates R of 2 microns/h have been obtained. Epitaxial growth of InAs was observed on both GaSb(100) and Si(100) substrates.

Influences of CdSe NCs on the photovoltaic parameters of BHJ organic solar cells.

Science.gov (United States)

Ongul, Fatih; Yuksel, Sureyya Aydin; Allahverdi, Cagdas; Bozar, Sinem; Kazici, Mehmet; Gunes, Serap

2018-04-05

In this study, the high quality CdSe nanocrystals (NCs) capped with stearic acid were synthesized in a solvent and then purified four times by using the precipitation and redissolution process. The average size of the synthesized CdSe NCs was determined ~3.0nm via transmission electron microscopy (TEM) measurement and their corresponding optical band edge energy was also calculated as ~2.1eV using ultraviolet-visible (UV-Vis) absorption spectroscopy. The bulk heterojunction (BHJ) hybrid solar cells based on a ternary system including P3HT, PCBM and CdSe NCs at different weight concentrations (0wt%, 0.1wt%, 0.5wt%, 1wt% and 2wt%) were fabricated by spin-casting process. The effect of the concentration of CdSe NCs on the photovoltaic parameters of these BHJ organic solar cells was investigated. The surface morphology of the photoactive layer modified by the incorporation of CdSe NCs into P3HT:PCBM matrix was observed with scanning electron microscopy (SEM). It was shown that when the concentration of CdSe NCs increases above 0.1wt% in this ternary system, the photovoltaic performance of the devices significantly decreases. The power conversion efficiency of the organic photovoltaic (OPV) device was enhanced ~20% by incorporating CdSe NCs with 0.1wt% with respect to those without CdSe NCs. Copyright © 2017 Elsevier B.V. All rights reserved.

30 CFR 57.22208 - Auxiliary fans (I-A, II-A, III, and V-A mines).

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Auxiliary fans (I-A, II-A, III, and V-A mines... fans (I-A, II-A, III, and V-A mines). (a) Auxiliary fans, except fans used in shops and other areas... applicable requirements of 30 CFR part 18, and be operated so that recirculation is minimized. Auxiliary fans...

High surface area V-Mo-N materials synthesized from amine intercalated foams

International Nuclear Information System (INIS)

Krawiec, Piotr; Narayan Panda, Rabi; Kockrick, Emanuel; Geiger, Dorin; Kaskel, Stefan

2008-01-01

Nanocrystalline ternary V-Mo nitrides were prepared via nitridation of amine intercalated oxide foams or bulk ternary oxides. Specific surface areas were in the range between 40 and 198 m 2 g -1 and strongly depended on the preparation method (foam or bulk oxide). Foamed precursors were favorable for vanadium rich materials, while for molybdenum rich samples bulk ternary oxides resulted in higher specific surface areas. The materials were characterized via nitrogen physisorption at 77 K, X-ray diffraction patterns, electron microscopy, and elemental analysis. - Graphical abstract: Nanocrystalline ternary V-Mo nitrides were prepared via nitridation of amine intercalated oxide foams or bulk ternary oxides. Foamed precursors were favorable for vanadium rich materials, while for molybdenum rich samples bulk ternary oxides resulted in higher specific surface areas

First-principles study on half-metallic ferromagnetic properties of Zn{sub 1-x}V{sub x}Se ternary alloys

Energy Technology Data Exchange (ETDEWEB)

Khatta, Swati; Tripathi, S.K.; Prakash, Satya [Panjab University, Central of Advanced Study in Physics, Department of Physics, Chandigarh (India)

2017-09-15

The spin-polarised density functional theory along with self-consistent plane-wave pseudopotential is used to investigate the half-metallic ferromagnetic properties of ternary alloys Zn{sub 1-x}V{sub x}Se. The generalized gradient approximation is used for exchange-correlation potential. The equilibrium lattice constants, bulk modulus, and its derivatives are calculated. The calculated spin-polarised energy-band structures reveal that these alloys are half-metallic for x = 0.375 and 0.50 and nearly half-metallic for other values of x. The estimated direct and indirect bandgaps may be useful for the magneto-optical absorption experiments. It is found that there is strong Zn 4s, Se 4p, and V 3d orbital hybridization in the conduction bands of both the spins, while Se 4p and V 3d orbital hybridization predominates in the valence bands of both the spins. The s, p-d, and p-d orbital hybridization reduces the local magnetic moment of V atoms and small local magnetic moments are produced on Zn and Se atoms which get coupled with V atoms in ferromagnetic and antiferromagnetic phases, respectively. The conduction and valence-band-edge splittings and exchange constants predict the ferromagnetism in these alloys. The conduction band-impurity (s and p-d) exchange interaction is more significant for ferromagnetism in these alloys than the valence band-impurity (p-d) exchange interaction. (orig.)

On the Nature of Ultra-faint Dwarf Galaxy Candidates. I. DES1, Eridanus III, and Tucana V

Science.gov (United States)

Conn, Blair C.; Jerjen, Helmut; Kim, Dongwon; Schirmer, Mischa

2018-01-01

We use deep Gemini/GMOS-S g, r photometry to study the three ultra-faint dwarf galaxy candidates DES1, Eridanus III (Eri III), and Tucana V (Tuc V). Their total luminosities, M V (DES1) = ‑1.42 ± 0.50 and M V (Eri III) = ‑2.07 ± 0.50, and mean metallicities, [{Fe}/{{H}}]=-{2.38}-0.19+0.21 and [{Fe}/{{H}}]=-{2.40}-0.12+0.19, are consistent with them being ultra-faint dwarf galaxies, as they fall just outside the 1σ confidence band of the luminosity–metallicity relation for Milky Way satellite galaxies. However, their positions in the size–luminosity relation suggest that they are star clusters. Interestingly, DES1 and Eri III are at relatively large Galactocentric distances, with DES1 located at {D}{GC}=74+/- 4 {kpc} and Eri III at {D}{GC}=91+/- 4 {kpc}. In projection, both objects are in the tail of gaseous filaments trailing the Magellanic Clouds and have similar 3D separations from the Small Magellanic Cloud (SMC): {{Δ }}{D}{SMC,{DES}1}=31.7 kpc and {{Δ }}{D}{SMC,{Eri}{III}}=41.0 kpc, respectively. It is plausible that these stellar systems are metal-poor SMC satellites. Tuc V represents an interesting phenomenon in its own right. Our deep photometry at the nominal position of Tuc V reveals a low-level excess of stars at various locations across the GMOS field without a well-defined center. An SMC Northern Overdensity–like isochrone would be an adequate match to the Tuc V color–magnitude diagram, and the proximity to the SMC (12.°1 {{Δ }}{D}{SMC,{Tuc}{{V}}}=13 kpc) suggests that Tuc V is either a chance grouping of stars related to the SMC halo or a star cluster in an advanced stage of dissolution.

Growth of Ag-seeded III-V Nanowires and TEM Characterization

DEFF Research Database (Denmark)

Lindberg, Anna Helmi Caroline

appropriate, the density and the vertical yield were obtained. The crystal structures for the grown nanowires have been investigated with TEM.We have also performed additional growths to further understand exactly how the nanowire growth proceeds as well as to understand the limitations of using Ag as a seed......This thesis deals with growth and characterization of GaAs and InAs nanowires. Today Au nanoparticle-seeding together with self-catalyzing are the dominating techniques to grow III-V nanowires with molecular beam epitaxy. In this thesis we instead investigate the possibility to use Ag as seed...... particle for growth of GaAs and InAs nanowires. The aim with the experiments performed has been to conclude whether Ag can be used to nucleate and grow nanowires on III-V substrates with molecular beam epitaxy. To investigate this we have performed growths of GaAs nanowires on GaAs(111)B and GaAs(100...

Substrate effects on the formation of flat Ag films on (110) surfaces of III-V compound semiconductors

International Nuclear Information System (INIS)

Chao, K.; Zhang, Z.; Ebert, P.; Shih, C.K.

1999-01-01

Ag films grown at 135 K on (110) surfaces of III-V compound semiconductors and annealed at room temperature are investigated by scanning tunneling microscopy and low-energy electron diffraction. Ag films on Ga-V semiconductors are well ordered, atomically flat, and exhibit a specific critical thickness, which is a function of the substrate material. Films grown on In-V semiconductors are still rather flat, but significantly more disordered. The (111) oriented Ag films on III-arsenides and III-phosphides exhibit a clear twofold superstructure. Films on III-antimonides exhibit threefold low-energy electron diffraction images. The morphology of the Ag films can be explained on the basis of the electronic growth mechanism. copyright 1999 The American Physical Society

SOLAR SOURCES OF 3He-RICH SOLAR ENERGETIC PARTICLE EVENTS IN SOLAR CYCLE 24

International Nuclear Information System (INIS)

Nitta, Nariaki V.; Mason, Glenn M.; Wang, Linghua; Cohen, Christina M. S.; Wiedenbeck, Mark E.

2015-01-01

Using high-cadence EUV images obtained by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory, we investigate the solar sources of 26 3 He-rich solar energetic particle events at ≲1 MeV nucleon −1 that were well-observed by the Advanced Composition Explorer during solar cycle 24. Identification of the solar sources is based on the association of 3 He-rich events with type III radio bursts and electron events as observed by Wind. The source locations are further verified in EUV images from the Solar and Terrestrial Relations Observatory, which provides information on solar activities in the regions not visible from the Earth. Based on AIA observations, 3 He-rich events are not only associated with coronal jets as emphasized in solar cycle 23 studies, but also with more spatially extended eruptions. The properties of the 3 He-rich events do not appear to be strongly correlated with those of the source regions. As in the previous studies, the magnetic connection between the source region and the observer is not always reproduced adequately by the simple potential field source surface model combined with the Parker spiral. Instead, we find a broad longitudinal distribution of the source regions extending well beyond the west limb, with the longitude deviating significantly from that expected from the observed solar wind speed

Analysis of the suitability of Al{sub x}Ga{sub 1-x}As as active material in III-V multiple-junction solar cells; Analyse zur Eignung von Al{sub x}Ga{sub 1-x}As als aktives Material in III-V Mehrfachsolarzellen

Energy Technology Data Exchange (ETDEWEB)

Heckelmann, Stefan

2017-05-01

In the past, Al{sub x}Ga{sub 1-x}As single and multiple-junction solar cells have been manufactured and tested. Although the ternary Al{sub x}Ga{sub 1-x}As is one of the most studied semiconductor systems, the results have often lagged behind expectations. In the thesis presented here, for the first time, the deep understanding of the Al{sub x}Ga{sub 1-x}As material system resulting from material analysis was linked with its application in solar cells. As has been shown, many cell results can only be explained if the peculiarities of the material, in particular the formation of DX centers and the transition from direct to indirect semiconductor, are also included. From this purposeful consideration of the material in terms of its usefulness in the semiconductor device and the technological significance of individual properties, not only high-quality solar cells based on Al{sub x}Ga{sub 1-x}As were produced but also new insights into the material properties of (Al{sub y}Ga{sub 1-y}){sub 1-z}In{sub z}As and the information gain from photoluminescence measurements can be significantly increased. [German] In der Vergangenheit wurden bereits Einfach- und Mehrfachsolarzellen aus Al{sub x}Ga{sub 1-x}As hergestellt und untersucht. Obwohl das ternaere Al{sub x}Ga{sub 1-x}As eines der meist untersuchten Halbleitersysteme ist, blieben die Ergebnisse oft hinter den Erwartungen zurueck. In der hier vorgestellten Dissertation wurde zum ersten Mal das aus der Materialanalytik heraus entstandene, tiefe Verstaendnis ueber das AlxGa1-xAs Materialsystem mit seiner Anwendung in Solarzellen verknuepft. Wie sich gezeigt hat, werden viele Zellergebnisse erst erklaerbar, wenn auch die Besonderheiten des Materials, insbesondere die Bildung von DX-Zentren und der Uebergang vom direkten zum indirekten Halbleiter, mit einbezogen werden. Aus dieser zielgerichteten Betrachtung des Materials im Hinblick auf seinen Nutzen im Halbleiterbauelement und der technologischen Bedeutung einzelner

Intensity of adjuvant chemotherapy regimens and grade III-V toxicities among elderly stage III colon cancer patients.

Science.gov (United States)

van Erning, F N; Razenberg, L G E M; Lemmens, V E P P; Creemers, G J; Pruijt, J F M; Maas, H A A M; Janssen-Heijnen, M L G

2016-07-01

The aim of this study was to provide insight in the use, intensity and toxicity of therapy with capecitabine and oxaliplatin (CAPOX) and capecitabine monotherapy (CapMono) among elderly stage III colon cancer patients treated in everyday clinical practice. Data from the Netherlands Cancer Registry were used. All stage III colon cancer patients aged ≥70 years diagnosed in the southeastern part between 2005 and 2012 and treated with CAPOX or CapMono were included. Differences in completion of all planned cycles, cumulative dosages and toxicity between both regimens were evaluated. One hundred ninety-three patients received CAPOX and 164 patients received CapMono; 33% (n = 63) of the patients receiving CAPOX completed all planned cycles of both agents, whereas 55% (n = 90) of the patients receiving CapMono completed all planned cycles (P characteristics, CapMono was associated with a lower odds of developing grade III-V toxicity than CAPOX (odds ratio 0.54, 95% confidence interval 0.33-0.89). For patients treated with CAPOX, the most common toxicities were gastrointestinal (29%), haematological (14%), neurological (11%) and other toxicity (13%). For patients treated with CapMono, dermatological (17%), gastrointestinal (13%) and other toxicity (11%) were the most common. CAPOX is associated with significantly more grade III-V toxicities than CapMono, which had a pronounced impact on the cumulative dosage received and completion of all planned cycles. In this light, CapMono seems preferable over CAPOX. Copyright © 2016 Elsevier Ltd. All rights reserved.

Determination of As(III) and As(V) by Flow Injection-Hydride Generation-Atomic Absorption Spectrometry via On-line Reduction of As(V) by KI

DEFF Research Database (Denmark)

Nielsen, Steffen; Hansen, Elo Harald

1997-01-01

A volume-based flow injection (FI) procedure is described for the determination and speciation of trace inorganic arsenic, As(III) and As(V), via hydride generation-atomic absorption spectrometry (HG-AAS) of As(III). The determination of total arsenic is obtained by on-line reduction of As(V) to As...

Robust tribo-mechanical and hot corrosion resistance of ultra-refractory Ta-Hf-C ternary alloy films.

Science.gov (United States)

Yate, Luis; Coy, L Emerson; Aperador, Willian

2017-06-08

In this work we report the hot corrosion properties of binary and ternary films of the Ta-Hf-C system in V 2 O 5 -Na 2 SO 4 (50%wt.-50%wt.) molten salts at 700 °C deposited on AISI D3 steel substrates. Additionally, the mechanical and nanowear properties of the films were studied. The results show that the ternary alloys consist of solid solutions of the TaC and HfC binary carbides. The ternary alloy films have higher hardness and elastic recoveries, reaching 26.2 GPa and 87%, respectively, and lower nanowear when compared to the binary films. The corrosion rates of the ternary alloys have a superior behavior compared to the binary films, with corrosion rates as low as 0.058 μm/year. The combination and tunability of high hardness, elastic recovery, low nanowear and an excellent resistance to high temperature corrosion demonstrates the potential of the ternary Ta-Hf-C alloy films for applications in extreme conditions.

Ion Implantation in III-V Compound Semiconductors

Science.gov (United States)

1984-09-01

340 keV H + -0 Ga P  O UES-723-292 !:• (H o>ray *P-K X - rayO Ga-K X -ray iii! RBS * ..I -iO.. 0 10I to1. 01 • .0 -. I0 1 LI =i, O I 0 01 0.J 10...Identity by blo ," pume) Ion Implantation, GaAs, Hall effect, electrical resistivity, Rutherford Backscattering (RBS), channeling, Proton induced x -ray...Mebility (jH) upon Aiinealing Temperature (TA) for 1 X 101 /cm• Dose Samples of GaAs:Mg with Three Different Capping Methods 33 p 14 Dependence of Surface

Multi-parametric Effect of Solar Activity on Cosmic Rays V. K. Mishra ...

Indian Academy of Sciences (India)

Key words. Sun—solar parameters—cosmic ray modulation—running ... Neutron monitors are most sensitive to cosmic rays in the energy range. 0.5–20 GeV ... been considered as a primary indicator to define the level of solar activity, which.

First-principles interatomic potentials for transition-metal aluminides. III. Extension to ternary phase diagrams

International Nuclear Information System (INIS)

Widom, Mike; Al-Lehyani, Ibrahim; Moriarty, John A.

2000-01-01

Modeling structural and mechanical properties of intermetallic compounds and alloys requires detailed knowledge of their interatomic interactions. The first two papers of this series [Phys. Rev. B 56, 7905 (1997); 58, 8967 (1998)] derived first-principles interatomic potentials for transition-metal (TM) aluminides using generalized pseudopotential theory (GPT). Those papers focused on binary alloys of aluminum with first-row transition metals and assessed the ability of GPT potentials to reproduce and elucidate the alloy phase diagrams of Al-Co and Al-Ni. This paper addresses the phase diagrams of the binary alloy Al-Cu and the ternary systems Al-Co-Cu and Al-Co-Ni, using GPT pair potentials calculated in the limit of vanishing transition-metal concentration. Despite this highly simplifying approximation, we find rough agreement with the known low-temperature phase diagrams, up to 50% total TM concentration provided the Co fraction is below 25%. Full composition-dependent potentials and many-body interactions would be required to correct deficiencies at higher Co concentration. Outside this troublesome region, the experimentally determined stable and metastable phases all lie on or near the convex hull of a scatter plot of energy versus composition. We verify, qualitatively, reported solubility ranges extending binary alloys into the ternary diagram in both Al-Co-Cu and Al-Co-Ni. Finally, we reproduce previously conjectured transition-metal positions in the decagonal quasicrystal phase. (c) 2000 The American Physical Society

Nanomaterials for solar energy

KAUST Repository

Revaprasadu, Neerish

2013-01-01

Nanostructured metal chalcogenides of the elements copper, iron, tin, lead and cadmium have attracted interest in their use as colloidal nanocrystal inks for solar cells. Some of these materials have the advantages of being available in abundance and having low toxicity. Developing methods for the combination of the elements to produce binary, ternary and quaternary compounds has dominated research in the field. This chapter will provide the most recent developments (from year 2012 onwards) for the synthesis and use of colloidal nanocrystal inks for solar cell applications. © The Royal Society of Chemistry 2014.

Integration of Semiconducting Sulfides for Full-Spectrum Solar Energy Absorption and Efficient Charge Separation.

Science.gov (United States)

Zhuang, Tao-Tao; Liu, Yan; Li, Yi; Zhao, Yuan; Wu, Liang; Jiang, Jun; Yu, Shu-Hong

2016-05-23

The full harvest of solar energy by semiconductors requires a material that simultaneously absorbs across the whole solar spectrum and collects photogenerated electrons and holes separately. The stepwise integration of three semiconducting sulfides, namely ZnS, CdS, and Cu2-x S, into a single nanocrystal, led to a unique ternary multi-node sheath ZnS-CdS-Cu2-x S heteronanorod for full-spectrum solar energy absorption. Localized surface plasmon resonance (LSPR) in the nonstoichiometric copper sulfide nanostructures enables effective NIR absorption. More significantly, the construction of pn heterojunctions between Cu2-x S and CdS leads to staggered gaps, as confirmed by first-principles simulations. This band alignment causes effective electron-hole separation in the ternary system and hence enables efficient solar energy conversion. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Concomitant glenohumeral pathologies associated with acute and chronic grade III and grade V acromioclavicular joint injuries.

Science.gov (United States)

Jensen, Gunnar; Millett, Peter J; Tahal, Dimitri S; Al Ibadi, Mireille; Lill, Helmut; Katthagen, Jan Christoph

2017-08-01

The purpose of this study was to identify the risk of concomitant glenohumeral pathologies with acromioclavicular joint injuries grade III and V. Patients who underwent arthroscopically-assisted stabilization of acromioclavicular joint injuries grade III or grade V between 01/2007 and 12/2015 were identified in the patient databases of two surgical centres. Gender, age at index surgery, grade of acromioclavicular joint injury (Rockwood III or Rockwood V), and duration between injury and index surgery (classified as acute or chronic) were of interest. Concomitant glenohumeral pathologies were noted and their treatment was classified as debridement or reconstructive procedure. A total of 376 patients (336 male, 40 female) were included. Mean age at time of arthroscopic acromioclavicular joint reconstruction surgery was 42.1 ± 14.0 years. Overall, 201 patients (53%) had one or more concomitant glenohumeral pathologies. Lesions of the biceps tendon complex and rotator cuff were the most common. Forty-five patients (12.0%) had concomitant glenohumeral pathologies that required an additional repair. The remaining 156 patients (41.5%) received a debridement of their concomitant pathologies. Rockwood grade V compared to Rockwood grade III (p = 0.013; odds ratio 1.7), and chronic compared to acute injury were significantly associated with having a concomitant glenohumeral pathology (p = 0.019; odds ratio 1.7). The probability of having a concomitant glenohumeral pathology was also significantly associated with increasing age (p acromioclavicular joint injury of either grade III or V. Twenty-two percent of these patients with concomitant glenohumeral pathologies received an additional dedicated repair procedure. Although a significant difference in occurrence of concomitant glenohumeral pathologies was seen between Rockwood grades III and V, and between acute and chronic lesions, increasing age was identified as the most dominant predictor. Level IV, case series.

Quiet-time Suprathermal (~0.1-1.5 keV) Electrons in the Solar Wind

Science.gov (United States)

Tao, Jiawei; Wang, Linghua; Zong, Qiugang; Li, Gang; Salem, Chadi S.; Wimmer-Schweingruber, Robert F.; He, Jiansen; Tu, Chuanyi; Bale, Stuart D.

2016-03-01

We present a statistical survey of the energy spectrum of solar wind suprathermal (˜0.1-1.5 keV) electrons measured by the WIND 3DP instrument at 1 AU during quiet times at the minimum and maximum of solar cycles 23 and 24. After separating (beaming) strahl electrons from (isotropic) halo electrons according to their different behaviors in the angular distribution, we fit the observed energy spectrum of both strahl and halo electrons at ˜0.1-1.5 keV to a Kappa distribution function with an index κ and effective temperature Teff. We also calculate the number density n and average energy Eavg of strahl and halo electrons by integrating the electron measurements between ˜0.1 and 1.5 keV. We find a strong positive correlation between κ and Teff for both strahl and halo electrons, and a strong positive correlation between the strahl n and halo n, likely reflecting the nature of the generation of these suprathermal electrons. In both solar cycles, κ is larger at solar minimum than at solar maximum for both strahl and halo electrons. The halo κ is generally smaller than the strahl κ (except during the solar minimum of cycle 23). The strahl n is larger at solar maximum, but the halo n shows no difference between solar minimum and maximum. Both the strahl n and halo n have no clear association with the solar wind core population, but the density ratio between the strahl and halo roughly anti-correlates (correlates) with the solar wind density (velocity).

Inhibition of the Fe(III)-catalyzed dopamine oxidation by ATP and its relevance to oxidative stress in Parkinson's disease.

Science.gov (United States)

Jiang, Dianlu; Shi, Shuyun; Zhang, Lin; Liu, Lin; Ding, Bingrong; Zhao, Bingqing; Yagnik, Gargey; Zhou, Feimeng

2013-09-18

Parkinson's disease (PD) is characterized by the progressive degeneration of dopaminergic cells, which implicates a role of dopamine (DA) in the etiology of PD. A possible DA degradation pathway is the Fe(III)-catalyzed oxidation of DA by oxygen, which produces neuronal toxins as side products. We investigated how ATP, an abundant and ubiquitous molecule in cellular milieu, affects the catalytic oxidation reaction of dopamine. For the first time, a unique, highly stable DA-Fe(III)-ATP ternary complex was formed and characterized in vitro. ATP as a ligand shifts the catecholate-Fe(III) ligand metal charge transfer (LMCT) band to a longer wavelength and the redox potentials of both DA and the Fe(III) center in the ternary complex. Remarkably, the additional ligation by ATP was found to significantly reverse the catalytic effect of the Fe(III) center on the DA oxidation. The reversal is attributed to the full occupation of the Fe(III) coordination sites by ATP and DA, which blocks O2 from accessing the Fe(III) center and its further reaction with DA. The biological relevance of this complex is strongly implicated by the identification of the ternary complex in the substantia nigra of rat brain and its attenuation of cytotoxicity of the Fe(III)-DA complex. Since ATP deficiency accompanies PD and neurotoxin 1-methyl-4-phenylpyridinium (MPP(+)) induced PD, deficiency of ATP and the resultant impairment toward the inhibition of the Fe(III)-catalyzed DA oxidation may contribute to the pathogenesis of PD. Our finding provides new insight into the pathways of DA oxidation and its relationship with synaptic activity.

The mechanisms of detoxification of As(III), dimethylarsinic acid (DMA) and As(V) in the microalga Chlorella vulgaris.

Science.gov (United States)

Pantoja Munoz, L; Purchase, D; Jones, H; Raab, A; Urgast, D; Feldmann, J; Garelick, H

2016-06-01

The response of Chlorella vulgaris when challenged by As(III), As(V) and dimethylarsinic acid (DMA) was assessed through experiments on adsorption, efflux and speciation of arsenic (reduction, oxidation, methylation and chelation with glutathione/phytochelatin [GSH/PC]). Our study indicates that at high concentrations of phosphate (1.62mM of HPO4(2-)), upon exposure to As(V), cells are able to shift towards methylation of As(V) rather than PC formation. Treatment with As(V) caused a moderate decrease in intracellular pH and a strong increase in the concentration of free thiols (GSH). Passive surface adsorption was found to be negligible for living cells exposed to DMA and As(V). However, adsorption of As(III) was observed to be an active process in C. vulgaris, because it did not show saturation at any of the exposure periods. Chelation of As(III) with GS/PC and to a lesser extent hGS/hPC is a major detoxification mechanism employed by C. vulgaris cells when exposed to As(III). The increase of bound As-GS/PC complexes was found to be strongly related to an increase in concentration of As(III) in media. C. vulgaris cells did not produce any As-GS/PC complex when exposed to As(V). This may indicate that a reduction step is needed for As(V) complexation with GSH/PC. C. vulgaris cells formed DMAS(V)-GS upon exposure to DMA independent of the exposure period. As(III) triggers the formation of arsenic complexes with PC and homophytochelatins (hPC) and their compartmentalisation to vacuoles. A conceptual model was devised to explain the mechanisms involving ABCC1/2 transport. The potential of C. vulgaris to bio-remediate arsenic from water appeared to be highly selective and effective without the potential hazard of reducing As(V) to As(III), which is more toxic to humans. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of calcium on adsorptive removal of As(III) and As(V) by iron oxide-based adsorbents

KAUST Repository

Uwamariya, V.; Petruševski, Branislav; Lens, Piet Nl L; Amy, Gary L.

2014-01-01

for filter columns with IOCS and GFH, respectively. The adsorption of As(III) and As(V) onto GFH follows a second-order reaction, with and without addition of calcium. The adsorption of As(III) and As(V) onto IOCS follows a first-order reaction without

Spectrophotometric Study of Ternary Complex Forming Systems of Some Lanthanide Metal Ions with Eriochrome Cyanine R in Presence of Cetylpyridinium Bromide for Microdetermination

Directory of Open Access Journals (Sweden)

A. S. Dhepe

2011-01-01

Full Text Available Study of coordination compounds of lanthanide elements has received a great attention due to growing applications in science and technology. Number of chromogenic reagents form water soluble colored complexes with lanthanides. Eriochrome cyanine R (ECR a member of triphenylmethane type of dye has been reported to form green colored complexes with lanthanides and has been used for microdetermination of these metal ions. Addition of cationic surfactant, Cetylpyridinium bromide (CPB, a cationic surfactant sensitizes the color reactions of Gd(III, Tb(III, Dy(III, Ho(III and Lu(III with ECR. Formation of water soluble, highly colored ternary complexes with a considerable bathochromic shift of about 50 nm in presence of surfactant has been observed. Optimum reaction conditions and other analytical parameters were also evaluated. Stoichiometric ratio 1:3:3 of Ln: ECR: CPB are responsible for the observed rise in molar absorptivity and sensitivity. Beer’s law was obeyed between 0.50 to 13.00 ppm. Effective photometric range and molar absorptivity of these ternary complexes have been calculated. Effect of some common interfering ions on determination of these lanthanide metal ions was studied. A simple, rapid and highly sensitive spectrophotometeric method has been proposed for the determination of metal ions understudy.

Development and application of high strength ternary boride base cermets

International Nuclear Information System (INIS)

Takagi, Ken-ichi

2006-01-01

Reaction boronizing sintering is a novel strategy to form a ternary boride coexisting with a metal matrix in a cermet during liquid phase sintering. This new sintering technique has successfully developed world first ternary boride base cermets with excellent mechanical properties such as Mo 2 FeB 2 , Mo 2 NiB 2 and WCoB base ones. In these cermets Mo 2 FeB 2 and Mo 2 NiB 2 base ones consist of a tetragonal M 3 B 2 (M: metal)-type complex boride as a hard phase and a transition metal base matrix. The cermets have already been applied to wear resistant applications such as injection molding machine parts, can making tools, and hot copper extruding dies, etc. This paper focuses on the characteristics, effects of the additional elements on the mechanical properties and structure, and practical applications of the ternary boride base cermets. - Graphical abstract: TRS and hardness of Ni-5B-51Mo-17.5Cr and Ni-5B-51Mo-12.5Cr-5V-xMn mass% cermets as functions of Mn content (Fig. 17)

Removal of Sb(III and Sb(V by Ferric Chloride Coagulation: Implications of Fe Solubility

Directory of Open Access Journals (Sweden)

Muhammad Ali Inam

2018-04-01

Full Text Available Coagulation and precipitation appear to be the most efficient and economical methods for the removal of antimony from aqueous solution. In this study, antimony removal from synthetic water and Fe solubility with ferric chloride (FC coagulation has been investigated. The effects of pH, FC dosage, initial antimony loading and mixed Sb(III, Sb(V proportions on Fe solubility and antimony removal were studied. The results showed that the Sb(III removal efficiency increased with the increase of solution pH particularly due to an increase in Fe precipitation. The Sb(V removal was influenced by the solution pH due to a change in Fe solubility. However, the Fe solubility was only impaired by the Sb(III species at optimum pH 7. The removal efficiencies of both Sb species were enhanced with an increase in FC dose. The quantitative analysis of the isotherm study revealed the strong adsorption potential of Sb(III on Fe precipitates as compared to Sb(V. Furthermore, the removal behavior of antimony was inhibited in mixed proportion with high Sb(V fraction. In conclusion, this study contributes to better understanding the fate of Sb species, their mobilities, and comparative removal behavior, with implications for Fe solubility using ferric chloride in different aqueous environments.

Results from an International Measurement Round Robin of III-V Triple Junction Solar Cells under Air Mass Zero

Science.gov (United States)

Jenkins, Phillip; Scheiman, Chris; Goodbody, Chris; Baur, Carsten; Sharps, Paul; Imaizumi, Mitsuru; Yoo, Henry; Sahlstrom, Ted; Walters, Robert; Lorentzen, Justin;

Coherent-potential approximation for the lattice vibrations of mixed III-V crystals

International Nuclear Information System (INIS)

Kleinert, P.

1984-01-01

The coherent-potential approximation (CPA) is applied to the lattice dynamics of some III-V mixed crystals. The calculations are based on an eleven-parameter rigid-ion model (RIM 11). Explicit results are reported for the one-mode system In/sub 1-c/Ga/sub c/P and the two mixed-mode crystals In/sub 1-c/Ga/sub c/Sb and GaSb/sub 1-c/As/sub c/. Both, the reflectivity spectra and the composition dependence of vibrations at the GAMMA and X points are compared with existing experimental data. Force-constant changes are considered by the virtual-crystal approximation (VCA). The CPA theory is uniquely successful for III-V mixed-mode systems, which appear to switch from one-mode to two-mode behaviour. (author)

Band structure effects on resonant tunneling in III-V quantum wells versus two-dimensional vertical heterostructures

Energy Technology Data Exchange (ETDEWEB)

Campbell, Philip M., E-mail: philip.campbell@gatech.edu [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Electronic Systems Laboratory, Georgia Tech Research Institute, Atlanta, Georgia 30332 (United States); Tarasov, Alexey; Joiner, Corey A.; Vogel, Eric M. [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Ready, W. Jud [Electronic Systems Laboratory, Georgia Tech Research Institute, Atlanta, Georgia 30332 (United States)

2016-01-14

Since the invention of the Esaki diode, resonant tunneling devices have been of interest for applications including multi-valued logic and communication systems. These devices are characterized by the presence of negative differential resistance in the current-voltage characteristic, resulting from lateral momentum conservation during the tunneling process. While a large amount of research has focused on III-V material systems, such as the GaAs/AlGaAs system, for resonant tunneling devices, poor device performance and device-to-device variability have limited widespread adoption. Recently, the symmetric field-effect transistor (symFET) was proposed as a resonant tunneling device incorporating symmetric 2-D materials, such as transition metal dichalcogenides (TMDs), separated by an interlayer barrier, such as hexagonal boron-nitride. The achievable peak-to-valley ratio for TMD symFETs has been predicted to be higher than has been observed for III-V resonant tunneling devices. This work examines the effect that band structure differences between III-V devices and TMDs has on device performance. It is shown that tunneling between the quantized subbands in III-V devices increases the valley current and decreases device performance, while the interlayer barrier height has a negligible impact on performance for barrier heights greater than approximately 0.5 eV.

Band structure effects on resonant tunneling in III-V quantum wells versus two-dimensional vertical heterostructures

Science.gov (United States)

Campbell, Philip M.; Tarasov, Alexey; Joiner, Corey A.; Ready, W. Jud; Vogel, Eric M.

2016-01-01

Since the invention of the Esaki diode, resonant tunneling devices have been of interest for applications including multi-valued logic and communication systems. These devices are characterized by the presence of negative differential resistance in the current-voltage characteristic, resulting from lateral momentum conservation during the tunneling process. While a large amount of research has focused on III-V material systems, such as the GaAs/AlGaAs system, for resonant tunneling devices, poor device performance and device-to-device variability have limited widespread adoption. Recently, the symmetric field-effect transistor (symFET) was proposed as a resonant tunneling device incorporating symmetric 2-D materials, such as transition metal dichalcogenides (TMDs), separated by an interlayer barrier, such as hexagonal boron-nitride. The achievable peak-to-valley ratio for TMD symFETs has been predicted to be higher than has been observed for III-V resonant tunneling devices. This work examines the effect that band structure differences between III-V devices and TMDs has on device performance. It is shown that tunneling between the quantized subbands in III-V devices increases the valley current and decreases device performance, while the interlayer barrier height has a negligible impact on performance for barrier heights greater than approximately 0.5 eV.

Silicon photonics fiber-to-the-home transceiver array based on transfer-printing-based integration of III-V photodetectors.

Science.gov (United States)

Zhang, Jing; De Groote, Andreas; Abbasi, Amin; Loi, Ruggero; O'Callaghan, James; Corbett, Brian; Trindade, António José; Bower, Christopher A; Roelkens, Gunther

2017-06-26

A 4-channel silicon photonics transceiver array for Point-to-Point (P2P) fiber-to-the-home (FTTH) optical networks at the central office (CO) side is demonstrated. A III-V O-band photodetector array was integrated onto the silicon photonic transmitter through transfer printing technology, showing a polarization-independent responsivity of 0.39 - 0.49 A/W in the O-band. The integrated PDs (30 × 40 μm 2 mesa) have a 3 dB bandwidth of 11.5 GHz at -3 V bias. Together with high-speed C-band silicon ring modulators whose bandwidth is up to 15 GHz, operation of the transceiver array at 10 Gbit/s is demonstrated. The use of transfer printing for the integration of the III-V photodetectors allows for an efficient use of III-V material and enables the scalable integration of III-V devices on silicon photonics wafers, thereby reducing their cost.

Efficient n-type doping of zinc-blende III-V semiconductor nanowires

Science.gov (United States)

Besteiro, Lucas V.; Tortajada, Luis; Souto, J.; Gallego, L. J.; Chelikowsky, James R.; Alemany, M. M. G.

2014-03-01

We demonstrate that it is preferable to dope III-V semiconductor nanowires by n-type anion substitution as opposed to cation substitution. Specifically, we show the dopability of zinc-blende nanowires is more efficient when the dopants are placed at the anion site as quantified by formation energies and the stabilization of DX-like defect centers. The comparison with previous work on n - type III-V semiconductor nanocrystals also allows to determine the role of dimensionality and quantum confinement on doping characteristics of materials. Our results are based on first-principles calculations of InP nanowires by using the PARSEC code. Work supported by the Spanish MICINN (FIS2012-33126) and Xunta de Galicia (GPC2013-043) in conjunction with FEDER. JRC acknowledges support from DoE (DE-FG02-06ER46286 and DESC0008877). Computational support was provided in part by CESGA.

Design of a novel quantum reversible ternary up-counter

Science.gov (United States)

Houshmand, Pouran; Haghparast, Majid

2015-08-01

Reversible logic has been recently considered as an interesting and important issue in designing combinational and sequential circuits. The combination of reversible logic and multi-valued logic can improve power dissipation, time and space utilization rate of designed circuits. Only few works have been reported about sequential reversible circuits and almost there are no paper exhibited about quantum ternary reversible counter. In this paper, first we designed 2-qutrit and 3-qutrit quantum reversible ternary up-counters using quantum ternary reversible T-flip-flop and quantum reversible ternary gates. Then we proposed generalized quantum reversible ternary n-qutrit up-counter. We also introduced a new approach for designing any type of n-qutrit ternary and reversible counter. According to the results, we can conclude that applying second approach quantum reversible ternary up-counter is better than the others.

Volumetric behaviour of binary and ternary liquid systems composed of ethanol, isooctane, and toluene at temperatures from (298.15 to 328.15) K. Experimental data and correlation

Energy Technology Data Exchange (ETDEWEB)

Moravkova, L.; Wagner, Z.; Sedlakova, Z. [E. Hala Laboratory of Thermodynamics, Institute of Chemical Process Fundamentals of the ASCR, v.v.i., 165 02 Prague 6 (Czech Republic); Linek, J., E-mail: linek@icpf.cas.cz [E. Hala Laboratory of Thermodynamics, Institute of Chemical Process Fundamentals of the ASCR, v.v.i., 165 02 Prague 6 (Czech Republic)

2011-12-15

Highlights: > We measured density and speed of sound at four temperatures within (298.15 to 328.15) K. > Excess quantities were calculated and fitted to the Redlich-Kister equation. > The complete ternary data were fitted to the modified Redlich-Kister equation. > Even for the systems with self-associating alcohol, only one ternary parameter is sufficient. - Abstract: The densities and speeds of sound of (ethanol + isooctane), (ethanol + toluene), and (ethanol + isooctane + toluene) were measured at four temperatures over the range (298.15 to 328.15) K, and the respective values of excess volumes V{sub m}{sup E} and adiabatic compressibility {kappa}{sub S} were calculated. The V{sub m}{sup E} and {kappa}{sub S} values for the binary systems were fitted to the Redlich-Kister equation. The respective ternary data together with corresponding binary data were then fitted to the modified Redlich-Kister equation considering various numbers of ternary constants. It was found that even for the systems containing self-associating alcohol, only one ternary parameter is sufficient to describe well the ternary system.

Monitoring ligand-dependent assembly of receptor ternary complexes in live cells by BRETFect.

Science.gov (United States)

Cotnoir-White, David; El Ezzy, Mohamed; Boulay, Pierre-Luc; Rozendaal, Marieke; Bouvier, Michel; Gagnon, Etienne; Mader, Sylvie

2018-03-13

There is currently an unmet need for versatile techniques to monitor the assembly and dynamics of ternary complexes in live cells. Here we describe bioluminescence resonance energy transfer with fluorescence enhancement by combined transfer (BRETFect), a high-throughput technique that enables robust spectrometric detection of ternary protein complexes based on increased energy transfer from a luciferase to a fluorescent acceptor in the presence of a fluorescent intermediate. Its unique donor-intermediate-acceptor relay system is designed so that the acceptor can receive energy either directly from the donor or indirectly via the intermediate in a combined transfer, taking advantage of the entire luciferase emission spectrum. BRETFect was used to study the ligand-dependent cofactor interaction properties of the estrogen receptors ERα and ERβ, which form homo- or heterodimers whose distinctive regulatory properties are difficult to dissect using traditional methods. BRETFect uncovered the relative capacities of hetero- vs. homodimers to recruit receptor-specific cofactors and regulatory proteins, and to interact with common cofactors in the presence of receptor-specific ligands. BRETFect was also used to follow the assembly of ternary complexes between the V2R vasopressin receptor and two different intracellular effectors, illustrating its use for dissection of ternary protein-protein interactions engaged by G protein-coupled receptors. Our results indicate that BRETFect represents a powerful and versatile technique to monitor the dynamics of ternary interactions within multimeric complexes in live cells.

Synthesis and luminescence properties of two novel europium (III) perchlorate complexes with bis(benzylsulfinyl)methane and 1,10-phenanthroline

Energy Technology Data Exchange (ETDEWEB)

Li, Wen-Xian, E-mail: nmglwx@163.com [College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021 (China); Guo, Feng [College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021 (China); Zheng, Yu-Shan [Inner Mongolia Autonomous Region Product Quality Inspection Institute, Hohhot 010010 (China); Cao, Xiao-Fang; Feng, Shu-Yan; Bai, Juan; Xin, Xiao-Dong [College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021 (China)

2014-09-15

Two novel binary and ternary Europium (III) perchlorate complexes were synthesized. The binary complex was prepared with bis(benzylsulfinyl)methane as ligand, and the ternary complex was with bis(benzylsulfinyl)methane as first ligand and 1,10-Phenanthroline as second ligand. They were characterized by element analysis, molar conductivity, coordination titration analysis, IR, TG-DSC, {sup 1}HNMR and UV spectra. The results indicated that the composition of binary and ternary complexes was EuL{sub 2.5}·(ClO{sub 4}){sub 3}·3H{sub 2}O and Eu{sub 2}L{sub 4}·phen·(ClO{sub 4}){sub 6}·12H{sub 2}O (L=C{sub 6}H{sub 5}CH{sub 2}SOCH{sub 2}SOCH{sub 2}C{sub 6}H{sub 5}), respectively. The fluorescent spectra illustrated that the complexes displayed characteristic Europium (III) ion fluorescence in solid state, indicating the ligands favored energy transfer to the excitation state energy level of it. The strongest characteristic fluorescence emission intensity of the ternary system was 1.87 times as strong as that of the binary system. The fluorescent quantum yields of the Eu (III) ternary and binary complexes were also calculated. Additionally, the phosphorescence spectra and the luminescence mechanisms of the complexes were studied and explained. - Highlights: • Two rare earth complexes are new. And they are stabilized. • The intensities of the two rare earth complexes were all stronger and the lifetimes were longer. • The introduction of the second organic ligand1,10-Phenanthroline enhanced the fluorescence intensity. • The fluorescent quantum yields of two complexes being calculated are both very high.

Physicochemical characterization of chitosan/nylon6/polyurethane foam chemically cross-linked ternary blends.

Science.gov (United States)

Jayakumar, S; Sudha, P N

2013-03-15

Chitosan/nylon6/polyurethane foam (CS/Ny6/PUF) ternary blend was prepared and chemically cross-linked with glutaraldehyde. Structural, thermal and morphological studies were performed for the prepared ternary blends. Characterizations of the ternary blends were investigated by Fourier transform infrared spectroscopy (FTIR), thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscope (SEM). The FTIR results showed that the strong intermolecular hydrogen bonds took place between CS, Ny6 and PUF. TGA and DSC studies reveal that the thermal stability of the blend is enhanced by glutaraldehyde as crosslinking agent. Results of XRD indicated that the relative crystalline of pure CS film was reduced when the polymeric network was reticulated by glutaraldehyde. Finally, the results of scanning electron microscopy (SEM) indicated that the morphology of the blend is rough and heterogeneous, further it confirms the interaction between the functional groups of the blend components. Copyright © 2012 Elsevier B.V. All rights reserved.

Search for sub-eV mass solar axions by the CERN Axion Solar Telescope with 3He buffer gas.

Science.gov (United States)

Arik, M; Aune, S; Barth, K; Belov, A; Borghi, S; Bräuninger, H; Cantatore, G; Carmona, J M; Cetin, S A; Collar, J I; Dafni, T; Davenport, M; Eleftheriadis, C; Elias, N; Ezer, C; Fanourakis, G; Ferrer-Ribas, E; Friedrich, P; Galán, J; García, J A; Gardikiotis, A; Gazis, E N; Geralis, T; Giomataris, I; Gninenko, S; Gómez, H; Gruber, E; Guthörl, T; Hartmann, R; Haug, F; Hasinoff, M D; Hoffmann, D H H; Iguaz, F J; Irastorza, I G; Jacoby, J; Jakovčić, K; Karuza, M; Königsmann, K; Kotthaus, R; Krčmar, M; Kuster, M; Lakić, B; Laurent, J M; Liolios, A; Ljubičić, A; Lozza, V; Lutz, G; Luzón, G; Morales, J; Niinikoski, T; Nordt, A; Papaevangelou, T; Pivovaroff, M J; Raffelt, G; Rashba, T; Riege, H; Rodríguez, A; Rosu, M; Ruz, J; Savvidis, I; Silva, P S; Solanki, S K; Stewart, L; Tomás, A; Tsagri, M; van Bibber, K; Vafeiadis, T; Villar, J A; Vogel, J K; Yildiz, S C; Zioutas, K

2011-12-23

The CERN Axion Solar Telescope (CAST) has extended its search for solar axions by using (3)He as a buffer gas. At T=1.8 K this allows for larger pressure settings and hence sensitivity to higher axion masses than our previous measurements with (4)He. With about 1 h of data taking at each of 252 different pressure settings we have scanned the axion mass range 0.39 eV≲m(a)≲0.64 eV. From the absence of excess x rays when the magnet was pointing to the Sun we set a typical upper limit on the axion-photon coupling of g(aγ)≲2.3×10(-10) GeV(-1) at 95% C.L., the exact value depending on the pressure setting. Kim-Shifman-Vainshtein-Zakharov axions are excluded at the upper end of our mass range, the first time ever for any solar axion search. In the future we will extend our search to m(a)≲1.15 eV, comfortably overlapping with cosmological hot dark matter bounds.

THE 'TWIN-CME' SCENARIO AND LARGE SOLAR ENERGETIC PARTICLE EVENTS IN SOLAR CYCLE 23

International Nuclear Information System (INIS)

Ding, Liuguan; Jiang, Yong; Zhao, Lulu; Li, Gang

2013-01-01

Energetic particles in large solar energetic particle (SEP) events are a major concern for space weather. Recently, Li et al. proposed a 'twin-CME' scenario for ground-level events. Here we extend that study to large SEP events in solar cycle 23. Depending on whether preceding coronal mass ejections (CMEs) within 9 hr exist and whether ions >10 MeV nucleon –1 exceed 10 pfu, we categorize fast CMEs with speed >900 km s –1 and width >60° from the western hemisphere source regions into four groups: groups I and II are 'twin' and single CMEs that lead to large SEPs; groups III and IV are 'twin' and single CMEs that do not lead to large SEPs. The major findings of this paper are: first, large SEP events tend to be 'twin-CME' events. Of 59 western large SEP events in solar cycle 23, 43 are 'twin-CME' (group I) events and 16 are single-CME (group II) events. Second, not all 'twin CMEs' produced large SEPs: 28 twin CMEs did not produce large SEPs (group III events). Some of them produced excesses of particles up to a few MeV nucleon –1 . Third, there were 39 single fast CMEs that did not produce SEPs (group IV events). Some of these also showed an excess of particles up to a few MeV nucleon –1 . For all four groups of events, we perform statistical analyses on properties such as the angular width, the speed, the existence of accompanying metric type II radio bursts, and the associated flare class for the main CMEs and the preceding CMEs.

Stable Solar-Blind Ultraviolet III-Nitride Photocathode for Astronomy Applications

Science.gov (United States)

Bell, Lloyd

In this effort, we propose to develop a new type of cesium-free photocathode using III- nitride materials (GaN, AlN, and their alloys) to achieve highly efficient, solar blind, and stable ultraviolet (UV) response. Currently, detectors used in UV instruments utilize a photocathode to convert UV photons into electrons that are subsequently detected by microchannel plate or CCD. The performance of these detectors critically depends on the efficiency and stability of their photocathodes. In particular, photocathode instability is responsible for many of the fabrication difficulties commonly experienced with this class of detectors. In recent years, III-nitride (in particular GaN) photocathodes have been demonstrated with very high quantum efficiency (>50%) in parts of UV spectral range; however, these photocathodes still rely on cesiation for activation. The proposed photocathode structure will achieve activation through methods for band structure engineering such as delta- doping and polarization field engineering. Compared to the current state-of-the-art in flight-ready microchannel plate/Cs2Te sealed tubes, photocathodes based on III-nitride materials will increase the quantum efficiency by nearly an order of magnitude and significantly enhance both fabrication yield and reliability, since they will not require cesium or other highly reactive materials for activation. This performance will enable a next-generation UV spectroscopic and imaging mission that is of high scientific priority for NASA. This photocathode uses near-surface band-structure engineering to create a permanently activated surface, with high efficiency and air-stable UV response. We will combine this III-nitride structure with our unique III-nitride processing technology to optimize the efficiency and uniformity of the photocathode. In addition, through our design, growth, and processing techniques, we will extend the application of these photocathodes into far UV for both semitransparent and

Uric acid levels in plasma and urine in rats chronically exposed to inorganic As (III) and As(V).

Science.gov (United States)

Jauge, P; Del-Razo, L M

1985-07-01

The effect of inorganic arsenic (III) and arsenic (V) on renal excretion and plasma levels of uric acid was examined in rats. Oral administration of 1200 micrograms As/kg/day for 6 weeks diminished uric acid levels in plasma by 67.1% and 26.5% of control after the administration of As(III) and As(V), respectively. Renal excretion of uric acid was significantly reduced during the first 3 weeks following As (III) administration, with a subsequent increase to approach control values at the end of the treatment. When As(V) was administered, the diminution in renal excretion was significant at 6 weeks.

Interplanetary ions during an energetic storm particle event: The distribution function from solar wind thermal energies to 1.6 MeV

International Nuclear Information System (INIS)

Gosling, J.T.; Asbridge, J.R.; Bame, S.J.; Feldman, W.C.; Zwickl, R.D.; Paschmann, G.; Sckopke, N.; Hynds, R.J.

1981-01-01

Data from the Los Alamos Scientific Laboratory/Max-Planck-Institut fast plasma experiment on Isee 2 have been combined with data from the European Space Agency/Imperial College/Space Research Laboratory low-energy proton experiment on Isee 3 to obtain for the first time an ion velocity distribution function f(v) extending from solar wind energies (-1 keV) to 1.6 MeV during the postshock phase of an energetic storm particle (ESP) event. This study reveals that f(v) of the ESP population is roughly isotropic in the solar wind frame from solar wind thermal energies out to 1.6 MeV. Emerging smoothly out of the solar wind thermal distribution, the ESP f(v) initially falls with increasing energy as E/sup -2.4/ in the solar wind frame. Above about 40 keV no single power law exponent adequately describes the energy dependence of f(v) in the solar wind frame. Above approx.200 keV in both the spacecraft frame and the solar wind frame, f(v) can be described by an exponential in speed (f(v)proportionale/sup -v/v//sub o/) with v/sub o/ = 1.05 x 10 8 cm s -1 . The ESP event studied (August 27, 1978) was superposed upon a more energetic particle event which was predominantly field-aligned and which was probably of solar origin. Our observations suggest that the ESP population is accelerated directly out of the solar wind thermal population or its quiescent suprathermal tail by a stochastic process associated with the shock wave disturbance. The acceleration mechanism is sufficiently efficient that approx.1% of the solar wind population is accelerated to suprathermal energies. These suprathermal particles have an energy density of approx.290 eV cm -3

Excess enthalpies of the ternary mixtures: {tetrahydrofuran + 3-methylpentane + (octane or decane)} at the temperature 298.15 K

International Nuclear Information System (INIS)

Wang Zhaohui; Benson, George C.; Lu, Benjamin C.-Y.

2003-01-01

Measurements of excess molar enthalpies at the temperature 298.15 K in a flow microcalorimeter, are reported for the two ternary mixtures {X 1 C 4 H 8 O + X 2 CH 3 CH 2 CH(CH 3 )CH 2 CH 3 + (1-X 1 -X 2 )CH 3 (CH 2 ) v-2 CH 3 } with v=8 and 10. Smooth representations of the results are described and used to construct constant-enthalpy contours on Roozeboom diagrams. It is shown that useful estimates of the ternary enthalpies can be obtained from the Liebermann-Fried model, using only the physical properties of the components and their binary mixtures

Spectroscopy and Speciation Studies on the Interactions of Aluminum (III with Ciprofloxacin and β-Nicotinamide Adenine Dinucleotide Phosphate in Aqueous Solutions

Directory of Open Access Journals (Sweden)

Xiaodi Yang

2012-08-01

Full Text Available In this study, both experimental and theoretical approaches, including absorption spectra, fluorescence emission spectra, ¹H- and ³¹P-NMR, electrospray ionization mass spectrometry (ESI-MS, pH-potentiometry and theoretical approaches using the BEST & SPE computer programs were applied to study the competitive complexation between ciprofloxacin (CIP and b-nicotinamide adenine dinucleotide phosphate (NADP with aluminum (III in aqueous solutions. Rank annihilation factor analysis (RAFA was used to analyze the absorption and fluorescence emission spectra of the ligands, the binary complexes and the ternary complexes. It is found, at the mM total concentration level and pH = 7.0, the bidentate mononuclear species [Al(CIP]²⁺ and [Al(NADP] predominate in the aqueous solutions of the Al(III-CIP and Al(III-NADP systems, and the two complexes have similar conditional stability constants. However, the pH-potentiometry results show at the mM total concentration level and pH = 7.0, the ternary species [Al(CIP(HNADP] predominates in the ternary complex system. Comparing predicted NMR spectra with the experimental NMR results, it can be concluded that for the ternary complex, CIP binds to aluminum ion between the 3-carboxylic and 4-carbonyl groups, while the binding site of oxidized coenzyme II is through the oxygen of phosphate, which is linked to adenosine ribose, instead of pyrophosphate. The results also suggested CIP has the potential to be a probe molecular for the detection of NADP and the Al(III-NADP complexes under physiological condition.

Sc-W-Si and Sc-W-Ge ternary systems

International Nuclear Information System (INIS)

Kotur, B.Ya.; Voznyak, O.M.; Bodak, O.I.

1989-01-01

Phase equilibria in Sc-W-Si and Sc-W-Ge ternary systems are investigated at 1070 K. Sc 2+x W 3-x Si 4 ternary compound (0≤x≤1) is determined, its crystal structure (Ce 2 Sc 3 Si 4 structural type), as well as, change of elementary cell parameters and microhardness within homogeneity range are determined. Regularities of component interaction within Sc-M-Si(Ge) (M-Cr, Mo, W) ternary system are determined. Ternary systems with Mo and W are more closer to each other according to the phase equilibria character, than to ternary systems with Cr

Performance Estimation for Lowpass Ternary Filters

Directory of Open Access Journals (Sweden)

Brenton Steele

2003-11-01

Full Text Available Ternary filters have tap values limited to −1, 0, or +1. This restriction in tap values greatly simplifies the multipliers required by the filter, making ternary filters very well suited to hardware implementations. Because they incorporate coarse quantisation, their performance is typically limited by tap quantisation error. This paper derives formulae for estimating the achievable performance of lowpass ternary filters, thereby allowing the number of computationally intensive design iterations to be reduced. Motivated by practical communications systems requirements, the performance measure which is used is the worst-case stopband attenuation.

Ternary gradient metal-organic frameworks.

Science.gov (United States)

Liu, Chong; Rosi, Nathaniel L

2017-09-08

Gradient MOFs contain directional gradients of either structure or functionality. We have successfully prepared two ternary gradient MOFs based on bMOF-100 analogues, namely bMOF-100/102/106 and bMOF-110/100/102, via cascade ligand exchange reactions. The cubic unit cell parameter discrepancy within an individual ternary gradient MOF crystal is as large as ∼1 nm, demonstrating the impressive compatibility and flexibility of the component MOF materials. Because of the presence of a continuum of unit cells, the pore diameters within individual crystals also change in a gradient fashion from ∼2.5 nm to ∼3.0 nm for bMOF-100/102/106, and from ∼2.2 nm to ∼2.7 nm for bMOF-110/100/102, indicating significant porosity gradients. Like previously reported binary gradient MOFs, the composition of the ternary gradient MOFs can be easily controlled by adjusting the reaction conditions. Finally, X-ray diffraction and microspectrophotometry were used to analyse fractured gradient MOF crystals by comparing unit cell parameters and absorbance spectra at different locations, thus revealing the profile of heterogeneity (i.e. gradient distribution of properties) and further confirming the formation of ternary gradient MOFs.

Printed assemblies of GaAs photoelectrodes with decoupled optical and reactive interfaces for unassisted solar water splitting

Science.gov (United States)

Kang, Dongseok; Young, James L.; Lim, Haneol; Klein, Walter E.; Chen, Huandong; Xi, Yuzhou; Gai, Boju; Deutsch, Todd G.; Yoon, Jongseung

2017-03-01

Despite their excellent photophysical properties and record-high solar-to-hydrogen conversion efficiency, the high cost and limited stability of III-V compound semiconductors prohibit their practical application in solar-driven photoelectrochemical water splitting. Here we present a strategy for III-V photocatalysis that can circumvent these difficulties via printed assemblies of epitaxially grown compound semiconductors. A thin film stack of GaAs-based epitaxial materials is released from the growth wafer and printed onto a non-native transparent substrate to form an integrated photocatalytic electrode for solar hydrogen generation. The heterogeneously integrated electrode configuration together with specialized epitaxial design serve to decouple the material interfaces for illumination and electrocatalysis. Subsequently, this allows independent control and optimization of light absorption, carrier transport, charge transfer, and material stability. Using this approach, we construct a series-connected wireless tandem system of GaAs photoelectrodes and demonstrate 13.1% solar-to-hydrogen conversion efficiency of unassisted-mode water splitting.

Design of ternary clocked adiabatic static random access memory

International Nuclear Information System (INIS)

Wang Pengjun; Mei Fengna

2011-01-01

Based on multi-valued logic, adiabatic circuits and the structure of ternary static random access memory (SRAM), a design scheme of a novel ternary clocked adiabatic SRAM is presented. The scheme adopts bootstrapped NMOS transistors, and an address decoder, a storage cell and a sense amplifier are charged and discharged in the adiabatic way, so the charges stored in the large switch capacitance of word lines, bit lines and the address decoder can be effectively restored to achieve energy recovery during reading and writing of ternary signals. The PSPICE simulation results indicate that the ternary clocked adiabatic SRAM has a correct logic function and low power consumption. Compared with ternary conventional SRAM, the average power consumption of the ternary adiabatic SRAM saves up to 68% in the same conditions. (semiconductor integrated circuits)

Design of ternary clocked adiabatic static random access memory

Science.gov (United States)

Pengjun, Wang; Fengna, Mei

2011-10-01

Based on multi-valued logic, adiabatic circuits and the structure of ternary static random access memory (SRAM), a design scheme of a novel ternary clocked adiabatic SRAM is presented. The scheme adopts bootstrapped NMOS transistors, and an address decoder, a storage cell and a sense amplifier are charged and discharged in the adiabatic way, so the charges stored in the large switch capacitance of word lines, bit lines and the address decoder can be effectively restored to achieve energy recovery during reading and writing of ternary signals. The PSPICE simulation results indicate that the ternary clocked adiabatic SRAM has a correct logic function and low power consumption. Compared with ternary conventional SRAM, the average power consumption of the ternary adiabatic SRAM saves up to 68% in the same conditions.

Synergistic Enhancement of Ternary Poly(3,4-ethylenedioxythiophene/Graphene Oxide/Manganese Oxide Composite as a Symmetrical Electrode for Supercapacitors

Directory of Open Access Journals (Sweden)

Nur Hawa Nabilah Azman

2018-06-01

Full Text Available A novel facile preparation of poly(3,4-ethylenedioxythiophene/graphene oxide/manganese oxide (PEDOT/GO/MnO2 ternary composite as an electrode material for a supercapacitor was evaluated. The ternary composite was sandwiched together and separated by filter paper soaked in 1 M KCl in order to investigate the supercapacitive properties. The ternary composite exhibits a higher specific capacitance (239.4 F/g compared to PEDOT/GO (73.3 F/g at 25 mV/s. The incorporation of MnO2 which act as a spacer in the PEDOT/GO helps to improve the supercapacitive performance by maximizing the utilization of electrode materials by the electrolyte ions. The PEDOT/GO/MnO2 ternary composite displays a specific energy and specific power of 7.9 Wh/kg and 489.0 W/kg, respectively. The cycling stability test revealed that the ternary composite is able to achieve 95% capacitance retention even after 1000 cycles due to the synergistic effect between the PEDOT, GO, and MnO2 that helps to enhance the performance of the ternary composite for supercapacitor application.

Structural characterization and bioavailability of ternary nanoparticles consisting of amylose, α-linoleic acid and β-lactoglobulin complexed with naringin.

Science.gov (United States)

Feng, Tao; Wang, Ke; Liu, Fangfang; Ye, Ran; Zhu, Xiao; Zhuang, Haining; Xu, Zhimin

2017-06-01

Naringin is a bioflavonoid that is rich in citrus plants and possesses enormous health benefits. However, the use of naringin as a nutraceutical is significantly limited by its low bioavailability. In this study, a novel water-soluble ternary nanoparticle material consisting of amylose, α-linoleic acid and β-lactoglobulin was developed to encapsulate naringin to improve its bioavailability. The physicochemical characteristics of the ternary nanoparticle-naringin inclusion complex were analysed by ultraviolet-visible spectroscopy (UV), Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), high-resolution transmission electron microscopy (TEM), X-ray diffractometry (XRD) and particle size distribution. The results confirmed the formation of the ternary nanoparticle-naringin inclusion complex. The encapsulation efficiency (EE) and loading content (LC) of the ternary nanoparticle-naringin inclusion complex were 78.73±4.17% and 14.51±3.43%, respectively. In addition, the results of the ternary nanoparticle-naringin inclusion complex in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) demonstrated that naringin can be gradually released from the complex. In conclusion, ternary nanoparticles are considered promising carriers to effectively improve the bioavailability of naringin. Copyright © 2017 Elsevier B.V. All rights reserved.

The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere V. On the Nature of the Corona

Directory of Open Access Journals (Sweden)

Robitaille P.-M.

2013-07-01

Full Text Available The E-corona is the site of numerous emission lines associated with high ionization states (i.e. FeXIV-FeXXV. Modern gaseous models of the Sun require that these states are produced by atomic irradiation, requiring the sequential removal of electrons to infinity, without an associated electron acceptor. This can lead to computed temperatures in the corona which are unrealistic (i.e. ∼30–100 MK contrasted to solar core values of ∼16 MK. In order to understand the emission lines of the E-corona, it is vital to recognize that they are superimposed upon the K-corona, which produces a continuous spectrum, devoid of Fraunhofer lines, arising from this same region of the Sun. It has been advanced that the K-corona harbors self-luminous condensed matter (Robitaille P.M. The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere II. Continuous Emission and Condensed Matter Within the Corona. Progr. Phys., 2013, v. 3, L8–L10; Robitaille P.M. The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere III. Importance of Continuous Emission Spectra from Flares, Coronal Mass Ejections, Prominences, and Other Coronal Structures. Progr. Phys., 2013, v. 3, L11–L14. Condensed matter can possess elevated electron affinities which may strip nearby atoms of their electrons. Such a scenario accounts for the high ionization states observed in the corona: condensed matter acts to harness electrons, ensuring the electrical neutrality of the Sun, despite the flow of electrons and ions in the solar winds. Elevated ionization states reflect the presence of materials with high electron affinities in the corona, which is likely to be a form of metallic hydrogen, and does not translate into elevated temperatures in this region of the solar atmosphere. As a result, the many mechanisms advanced to account for coronal heating in the gaseous models of the Sun

Structure and stability of hexa-aqua V(III) cations in vanadium redox flow battery electrolytes.

Science.gov (United States)

Vijayakumar, M; Li, Liyu; Nie, Zimin; Yang, Zhenguo; Hu, JianZhi

2012-08-07

The vanadium(III) cation structure in mixed acid based electrolyte solution from vanadium redox flow batteries is studied by (17)O and (35/37)Cl nuclear magnetic resonance (NMR) spectroscopy, electronic spectroscopy and density functional theory (DFT) based computational modelling. Both computational and experimental results reveal that the V(III) species can complex with counter anions (sulfate/chlorine) depending on the composition of its solvation sphere. By analyzing the powder precipitate it was found that the formation of sulfate complexed V(III) species is the crucial process in the precipitation reaction. The precipitation occurs through nucleation of neutral species formed through deprotonation and ion-pair formation process. However, the powder precipitate shows a multiphase nature which warrants multiple reaction pathways for precipitation reaction.

Generation of type III solar radio bursts: the role of induced scattering of plasma waves by ions

International Nuclear Information System (INIS)

Levin, B.N.; Lerner, A.M.; Rapoport, V.O.

1984-01-01

The plasma waves in type III solar radio-burst sources might have a spectrum which can explain why, in the quasilinear burst generation model, nonlinear scattering of the waves by ions is so weak. The agent exciting a burst would travel through the corona at velocities limited to a definite range

III-V Ultra-Thin-Body InGaAs/InAs MOSFETs for Low Standby Power Logic Applications

Science.gov (United States)

Huang, Cheng-Ying

As device scaling continues to sub-10-nm regime, III-V InGaAs/InAs metal- oxide-semiconductor ?eld-e?ect transistors (MOSFETs) are promising candidates for replacing Si-based MOSFETs for future very-large-scale integration (VLSI) logic applications. III-V InGaAs materials have low electron effective mass and high electron velocity, allowing higher on-state current at lower VDD and reducing the switching power consumption. However, III-V InGaAs materials have a narrower band gap and higher permittivity, leading to large band-to-band tunneling (BTBT) leakage or gate-induced drain leakage (GIDL) at the drain end of the channel, and large subthreshold leakage due to worse electrostatic integrity. To utilize III-V MOSFETs in future logic circuits, III-V MOSFETs must have high on-state performance over Si MOSFETs as well as very low leakage current and low standby power consumption. In this dissertation, we will report InGaAs/InAs ultra-thin-body MOSFETs. Three techniques for reducing the leakage currents in InGaAs/InAs MOSFETs are reported as described below. 1) Wide band-gap barriers: We developed AlAs0.44Sb0.56 barriers lattice-match to InP by molecular beam epitaxy (MBE), and studied the electron transport in In0.53Ga0.47As/AlAs 0.44Sb0.56 heterostructures. The InGaAs channel MOSFETs using AlAs0.44Sb0.56 bottom barriers or p-doped In0.52 Al0.48As barriers were demonstrated, showing significant suppression on the back barrier leakage. 2) Ultra-thin channels: We investigated the electron transport in InGaAs and InAs ultra-thin quantum wells and ultra-thin body MOSFETs (t ch ~ 2-4 nm). For high performance logic, InAs channels enable higher on-state current, while for low power logic, InGaAs channels allow lower BTBT leakage current. 3) Source/Drain engineering: We developed raised InGaAs and recessed InP source/drain spacers. The raised InGaAs source/drain spacers improve electrostatics, reducing subthreshold leakage, and smooth the electric field near drain, reducing

Formation constants of Sm(III), Dy(III), Gd(III), Pr(III) and Nd(III) complexes of tridentate schiff base, 2-[(1H-benzimidazol-2-yl-methylene) amino] phenol

International Nuclear Information System (INIS)

Omprakash, K.L.; Chandra Pal, A.V.; Reddy, M.L.N.

1982-01-01

A new tridentate schiff base, 2- (1H-benzimidazol-2-yl-methylene)amino phenol derived from benzimididazole-2-carbo-xaldehyde and 2-aminophenol has been synthesised and characterised by spectral and analytical data. Proton-ligand formation constants of the schiff base and metal-ligand formation constants of its complexes with Sm(III), Dy(III), Gd(III), Nd(III) and Pr(III) have been determined potentiometrically in 50% (v/v) aqueous dioxane at an ionic strength of 0.1M (NaClO 4 ) and at 25deg C using the Irving-Rossotti titration technique. The order of stability constants (logβ 2 ) is found to be Sm(III)>Dy(III)>Gd(III)>Pr(III)>Nd(III). (author)

Formation constants of Sm(III), Dy(III), Gd(III), Pr(III) and Nd(III) complexes of tridentate schiff base, 2-((1H-benzimidazol-2-yl-methylene) amino) phenol

Energy Technology Data Exchange (ETDEWEB)

Omprakash, K L; Chandra Pal, A V; Reddy, M L.N. [Osmania Univ., Hyderabad (India). Dept. of Chemistry

1982-03-01

A new tridentate schiff base, 2- (1H-benzimidazol-2-yl-methylene)amino phenol derived from benzimididazole-2-carbo-xaldehyde and 2-aminophenol has been synthesised and characterised by spectral and analytical data. Proton-ligand formation constants of the schiff base and metal-ligand formation constants of its complexes with Sm(III), Dy(III), Gd(III), Nd(III) and Pr(III) have been determined potentiometrically in 50% (v/v) aqueous dioxane at an ionic strength of 0.1M (NaClO/sub 4/) and at 25deg C using the Irving-Rossotti titration technique. The order of stability constants (log..beta../sub 2/) is found to be Sm(III)>Dy(III)>Gd(III)>Pr(III)>Nd(III).

GaAsP on GaP top solar cells

Science.gov (United States)

Mcneely, J. B.; Negley, G. H.; Barnett, A. M.

1985-01-01

GaAsP on GaP top solar cells as an attachment to silicon bottom solar cells are being developed. The GaAsP on GaP system offers several advantages for this top solar cell. The most important is that the gallium phosphide substrate provides a rugged, transparent mechanical substrate which does not have to be removed or thinned during processing. Additional advantages are that: (1) gallium phosphide is more oxidation resistant than the III-V aluminum compounds, (2) a range of energy band gaps higher than 1.75 eV is readily available for system efficiency optimization, (3) reliable ohmic contact technology is available from the light-emitting diode industry, and (4) the system readily lends itself to graded band gap structures for additional increases in efficiency.

Study of the interactions between Eu(III) and Al2O3 particles in the presence of phenolic acids

International Nuclear Information System (INIS)

Moreau, P.

2012-01-01

In the framework of environmental pollution by radionuclides, this work was focused on the interactions occurring in systems containing europium(III) - as a chemical analogue for the actinides Am(III) and Cm(III) -, phenolic acids - lignin degradation products and anti-fungi, naturally occurring in soils, and alumina - representative of sorption sites found in the environment. This study was conducted at different scales of description: the macroscopic scale - to quantify Eu(III) and/or phenolic acids adsorption onto the mineral surface -, and the microscopic scale - to study the chemical environment of Eu(III) using Time-Resolved Luminescence Spectroscopy (TRLS). First, the binary systems, i.e. systems containing only two entities among the three previously cited, were characterized. Complexation constants of Eu(III) by three phenolic acids (4-hydroxybenzoic, 3,4-dihydroxybenzoic, and 3,4,5-trihydroxybenzoic acids) were determined and quantum calculations (DFT) were carried out on La(III)-acid complex analogues. Sorption of the acids onto aluminol sites was modelled using surface complexation concepts. Analyses of two ternary systems (containing 4-hydroxybenzoic and 3,4-dihydroxybenzoic acids) revealed synergistic processes for Eu(III) and phenolic acids sorption onto Al 2 O 3 . A spectral fingerprint of ternary complex involving Eu(III)/4-hydroxybenzoic acid/Al 2 O 3 surface sites was evidenced. (author) [fr

30 CFR 57.22205 - Doors on main fans (I-A, II-A, III, and V-A mines).

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Doors on main fans (I-A, II-A, III, and V-A... main fans (I-A, II-A, III, and V-A mines). In mines ventilated by multiple main fans, each main fan... reversal through the fan. The doors shall be located so that they are not in direct line with explosive...

Cu2ZnSnS4 thin film solar cells from electroplated precursors: Novel low-cost perspective

International Nuclear Information System (INIS)

Ennaoui, A.; Lux-Steiner, M.; Weber, A.; Abou-Ras, D.; Koetschau, I.; Schock, H.-W.; Schurr, R.; Hoelzing, A.; Jost, S.; Hock, R.; Voss, T.; Schulze, J.; Kirbs, A.

2009-01-01

Thin-film solar cells based on Cu 2 ZnSnS 4 (CZTS) absorbers were fabricated successfully by solid-state reaction in H 2 S atmosphere of electrodeposited Cu-Zn-Sn precursors. These ternary alloys were deposited in one step from a cyanide-free alkaline electrolyte containing Cu(II), Zn (II) and Sn (IV) metal salts on Mo-coated glass substrates. The solar cell was completed by a chemical bath-deposited CdS buffer layer and a sputtered i-ZnO/ZnO:Al bilayer. The best solar cell performance was obtained with Cu-poor samples. A total area (0.5 cm 2 ) efficiency of 3.4% is achieved (V oc = 563 mV, j sc = 14.8 mA/cm 2 , FF = 41%) with a maximum external quantum efficiency (EQE) of 80%. The estimated band-gap energy from the external quantum efficiency (EQE) measurements is about 1.54 eV. Electron backscatter-diffraction maps of cross-section samples revealed CZTS grain sizes of up to 10 μm. Elemental distribution maps of the CZTS absorber show Zn-rich precipitates, probably ZnS, and a Zn-poor region, presumably Cu 2 SnS 3 , close to the interface Mo/CZTS

Effect of calcium on adsorptive removal of As(III) and As(V) by iron oxide-based adsorbents

KAUST Repository

Uwamariya, V.

2014-06-25

The effects of calcium on the equilibrium adsorption capacity of As(III) and As(V) onto iron oxide-coated sand (IOCS) and granular ferric hydroxide (GFH) were investigated through batch experiments, rapid small-scale column tests (RSSCT) and kinetics modelling. Batch experiments showed that at calcium concentrations≤20 mg/L, high As(III) and As(V) removal efficiencies by IOCS and GFH are achieved at pH 6. An increase of the calcium concentration to 40 and 80 mg/L reversed this trend, giving higher removal efficiencies at higher pH (8). The adsorption capacities of IOCS and GFH at an equilibrium arsenic concentration of 10 g/L were found to be between 2.0 and 3.1 mg/g for synthetic water without calcium and between 2.8 and 5.3 mg/g when 80 mg/L of calcium was present at the studied pH values. After 10 hours of filter run in RSSCT, approximately 1000 empty bed volumes, the ratios of C/Co for As(V) were 26% and 18% for calcium-free model water; and only 1% and 0.2% after addition of 80 mg/L of Ca for filter columns with IOCS and GFH, respectively. The adsorption of As(III) and As(V) onto GFH follows a second-order reaction, with and without addition of calcium. The adsorption of As(III) and As(V) onto IOCS follows a first-order reaction without calcium addition, and moves to the second-reaction-order kinetics when calcium is added. Based on the intraparticle diffusion model, the main controlling mechanism for As(III) adsorption is intraparticle diffusion, while surface diffusion contributes greatly to the adsorption of As(V).

Influences of CdSe NCs on the photovoltaic parameters of BHJ organic solar cells

Science.gov (United States)

Ongul, Fatih; Yuksel, Sureyya Aydin; Allahverdi, Cagdas; Bozar, Sinem; Kazici, Mehmet; Gunes, Serap

2018-04-01

In this study, the high quality CdSe nanocrystals (NCs) capped with stearic acid were synthesized in a solvent and then purified four times by using the precipitation and redissolution process. The average size of the synthesized CdSe NCs was determined 3.0 nm via transmission electron microscopy (TEM) measurement and their corresponding optical band edge energy was also calculated as 2.1 eV using ultraviolet-visible (UV-Vis) absorption spectroscopy. The bulk heterojunction (BHJ) hybrid solar cells based on a ternary system including P3HT, PCBM and CdSe NCs at different weight concentrations (0 wt%, 0.1 wt%, 0.5 wt%, 1 wt% and 2 wt%) were fabricated by spin-casting process. The effect of the concentration of CdSe NCs on the photovoltaic parameters of these BHJ organic solar cells was investigated. The surface morphology of the photoactive layer modified by the incorporation of CdSe NCs into P3HT:PCBM matrix was observed with scanning electron microscopy (SEM). It was shown that when the concentration of CdSe NCs increases above 0.1 wt% in this ternary system, the photovoltaic performance of the devices significantly decreases. The power conversion efficiency of the organic photovoltaic (OPV) device was enhanced 20% by incorporating CdSe NCs with 0.1 wt% with respect to those without CdSe NCs.

Evaluation of hyaluronic acid-combined ternary complexes for serum-resistant and targeted gene delivery system.

Science.gov (United States)

Hong, Woong-Gil; Jeong, Gyeong-Won; Nah, Jae-Woon

2018-04-19

Branched polyethylenimine (bPEI) was well known as high transfection agent, which has many amine group. However, utilization of bPEI was limited due to high toxicity. To solve these problems, bPEI was introduced to low molecular weight water-soluble chitosan (LMWSC) with coupling agent. In addition, hyaluronic acid (HA), one of natural anion polymer, was introduced to binary complex of pDNA/bPEI-grafted LMWSC (LMPEI) to target the specific cancer cell and impart the serum resistant. Ternary complexes of pDNA/LMPEI/HA were prepared by electrostatic charge interaction and their binding affinity and DNase protection assay were conducted by gel retardation assay. Particle size of ternary complexes showed that had each 482 ± 245.4 (pDNA/LMPEI2%/HA, 1:16:1, w/w/w) and 410 ± 78.5 nm (pDNA/LMPEI4%/HA, 1:16:2, w/w/w). Moreover, to demonstrate serum-resistant effect of ternary complexes, particle size of them was measured according to incubated time (0-10 h) under serum condition. Transfection assay of ternary complexes showed that their transfection efficiency in CD44-receptor overexpressed HCT116 cell was higher than CD44-receptor negative CT26 cell. Additionally, intracellular uptake of ternary complexes with propidium iodide (PI)-labeled pDNA was observed to confirm targeting effect and cellular internalization by fluorescence microscopy. These results suggest that ternary complexes are superb gene carrier with excellent serum-resistant and high gene transfection. Copyright © 2017. Published by Elsevier B.V.

Ordering and site occupancy of ternary elements in Fe{sub 3}Al

Energy Technology Data Exchange (ETDEWEB)

Rademacher, Thomas; Al-Kassab, Talaat; Kirchheim, Reiner [Institut fuer Materialphysik, Universitaet Goettingen (Germany)

2009-07-01

Ordered iron aluminides exhibit a number of advantageous properties, such as high-temperature strength, corrosion resistance and low cost. Therefore, iron aluminum based alloys are considered to replace in some cases high alloyed ferritic stainless steels, especially DO{sub 3} - ordered Fe{sub 3}Al. The mechanical properties and high-temperature stability can be optimized when ternary elements are added. In this study the site occupancy of ternary elements (4at.%V, 5at.%Cr, 5at.%Mn) has been investigated by means of Atom Probe Tomography (APT). A special analysis algorithm allows resolving the atom layers for different measurement directions which enables determining site preferences. Additionally, comparing the succession of layers with simulations the binding energies of the participating elements can be estimated.

All-optical symmetric ternary logic gate

Science.gov (United States)

Chattopadhyay, Tanay

2010-09-01

Symmetric ternary number (radix=3) has three logical states (1¯, 0, 1). It is very much useful in carry free arithmetical operation. Beside this, the logical operation using this type of number system is also effective in high speed computation and communication in multi-valued logic. In this literature all-optical circuits for three basic symmetrical ternary logical operations (inversion, MIN and MAX) are proposed and described. Numerical simulation verifies the theoretical model. In this present scheme the different ternary logical states are represented by different polarized state of light. Terahertz optical asymmetric demultiplexer (TOAD) based interferometric switch has been used categorically in this manuscript.

New insights into thorium and uranium oxo-arsenic (III/V) and oxo-phosphates (V) crystal chemistry

International Nuclear Information System (INIS)

Yu, Na

2015-01-01

The fundamental chemistry of actinides is of great interest owing to the diverse number of valence states and complex coordination chemistry of the actinides. The phases based on actinides and oxo-salt fragments have been under thorough investigation in the last decades. These compounds can be widely found in nature and they affect the migration process of actinides in nature. A better understanding of the fundamental coordination chemistry of actinide compounds with oxo-salts of group V elements is not only important for understanding the actinides behavior within the migration process but can also be used to understand actinide properties in phosphate ceramics. Concerning the radioactive issues, the less radioactive early actinides (i.e. U, Th) can be taken as modeling elements to study the crystal chemistry of the transuranic elements (Np, Pu) without the major handling problems. This can be done as Th(IV) has a very similar coordination chemistry with An(IV) and U(VI) can be chosen as a modeling element for transuranic elements in higher valence states. Therefore, a systematic research on the actinides (U, Th) bearing phases with tetrahedral oxo-anions such as phosphates and arsenates have been performed in this work. High temperature (HT) solid state reaction, High pressure high temperature (HP-HT) solid state reaction and the hydrothermal method were the methods of choice for synthesizing actinide bearing oxo-arsenic(III/V) and oxo- phosphorus(V) phases in the past three years. As a result, numerous novel compounds containing actinides were obtained. The structures of all compounds were determined using single crystal X-ray diffraction data. Raman spectroscopy, EDS, DSC and high temperature powder X-ray diffraction (HT-PXRD) measurements were implemented to characterize the chemical and physical properties of the obtained compounds. The core of this dissertation is a fundamental study of the crystal chemistry of actinides (Th, U) oxo-arsenic (III/V) and oxo-phosphate(V

Study on competitive adsorption mechanism among oxyacid-type heavy metals in co-existing system: Removal of aqueous As(V), Cr(III) and As(III) using magnetic iron oxide nanoparticles (MIONPs) as adsorbents

Science.gov (United States)

Lin, Sen; Lian, Cheng; Xu, Meng; Zhang, Wei; Liu, Lili; Lin, Kuangfei

2017-11-01

The adsorption and co-adsorption of As(V), Cr(VI) and As(III) onto the magnetic iron oxide nanoparticles (MIONPs) surface were investigated comprehensively to clarify the competitive processes. The results reflected that the MIONPs had remarkable preferential adsorption to As(V) compared with Cr(VI) and As(III). And it was determined, relying on the analysis of heavy metals variations on the MIONPs surface at different co-adsorption stages using FTIR and XPS, that the inner-sphere complexation made vital contribution to the preferential adsorption for As(V), corresponding with the replacement experiments where As(V) could grab extensively active sites on the MIONPs pre-occupied by As(III) or Cr(V) uniaxially. The desorption processes displayed that the strongest affinity between the MIONPs and As(V) where As(III) and Cr(VI) were more inclined to wash out. It is wish to provide a helpful direction with this study for the wastewater treatment involving multiple oxyacid-type heavy metals using MIONPs as adsorbents.

Structural features and electronic properties of group-III-, group-IV-, and group-V-doped Si nanocrystallites

International Nuclear Information System (INIS)

Ramos, L E; Degoli, Elena; Cantele, G; Ossicini, Stefano; Ninno, D; Furthmueller, J; Bechstedt, F

2007-01-01

We investigate the incorporation of group-III (B and Al), group-IV (C and Ge), and group-V (N and P) impurities in Si nanocrystallites. The structural features and electronic properties of doped Si nanocrystallites, which are faceted or spherical-like, are studied by means of an ab initio pseudopotential method including spin polarization. Jahn-Teller distortions occur in the neighborhood of the impurity sites and the bond lengths show a dependence on size and shape of the nanocrystallites. We find that the acceptor (group-III) and donor (group-V) levels become deep as the nanocrystallites become small. The energy difference between the spin-up and spin-down levels of group-III and group-V impurities decreases as the size of the Si nanocrystallite increases and tends to the value calculated for Si bulk. Doping with carbon introduces an impurity-related level in the energy gap of the Si nanocrystallites

Oxygen perovskites with pentavalent ruthenium A/sub 2/sup(II)Bsup(III)Rusup(V)O/sub 6/ with Asup(II) = Ba, Sr

Energy Technology Data Exchange (ETDEWEB)

Bader, H; Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

1980-07-01

The perovskites Ba/sub 2/Bsup(III)Rusup(V)O/sub 6/ with Bsup(III) = La, Nd, Sm, Eu, Gd, Dy, Y are cubic (Bsup(III) = La: a = 8.54 A; Y: a = 8.33 A) with a partial order for Bsup(III) and Rusup(V). The Sc compound, Ba/sub 2/ScRuO/sub 6/, has a hexagonal 6L structure (a = 5.79 A; c = 14.22 A; sequence (hcc)/sub 2/). The lattice of the Sr perovskites, Sr/sub 2/Bsup(III)Rusup(V)O/sub 6/, with Bsup(III) = Eu, Gd, Dy, Y is rhombic distorted. The IR and FIR spectra are discussed.

Towards III-V solar cells on Si: Improvement in the crystalline quality of Ge-on-Si virtual substrates through low porosity porous silicon buffer layer and annealing

International Nuclear Information System (INIS)

Calabrese, Gabriele; Baricordi, Stefano; Bernardoni, Paolo; Fin, Samuele; Guidi, Vincenzo; Vincenzi, Donato

2014-01-01

A comparison between the crystalline quality of Ge grown on bulk Si and on a low porosity porous Si (pSi) buffer layer using low energy plasma enhanced chemical vapor deposition is reported. Omega/2Theta coupled scans around the Ge and Si (004) diffraction peaks show a reduction of the Ge full-width at half maximum (FWHM) of 22.4% in presence of the pSi buffer layer, indicating it is effective in improving the epilayer crystalline quality. At the same time atomic force microscopy analysis shows an increase in root means square roughness for Ge grown on pSi from 38.5 nm to 48.0 nm, as a consequence of the larger surface roughness of pSi compared to bulk Si. The effect of 20 minutes vacuum annealing at 580°C is also investigated. The annealing leads to a FWHM reduction of 23% for Ge grown on Si and of 36.5% for Ge on pSi, resulting in a FWHM of 101 arcsec in the latter case. At the same time, the RMS roughness is reduced of 8.8% and of 46.5% for Ge grown on bulk Si and on pSi, respectively. The biggest improvement in the crystalline quality of Ge grown on pSi with respect to Ge grown on bulk Si observed after annealing is a consequence of the simultaneous reorganization of the Ge epilayer and the buffer layer driven by energy minimization. A low porosity buffer layer can thus be used for the growth of low defect density Ge on Si virtual substrates for the successive integration of III-V multijunction solar cells on Si. The suggested approach is simple and fast –thus allowing for high throughput-, moreover is cost effective and fully compatible with subsequent wafer processing. Finally it does not introduce new chemicals in the solar cell fabrication process and can be scaled to large area silicon wafers

Thermodynamic modeling of the Ti-Al-Cr ternary system

International Nuclear Information System (INIS)

Chen Leyi; Qiu Aitao; Liu Lanjie; Jiang Ming; Lu Xionggang; Li Chonghe

2011-01-01

Research highlights: → The full experimental results of the Ti-Al-Cr ternary system and its sub-binary systems are reviewed and analysed in detail. → Based on the latest thermodynamic assessments of the Ti-Al, Ti-Cr and Al-Cr systems and the ternary experimental data in literature, the thermodynamic parameters of the Ti-Al-Cr ternary system are fully assessed by the Calphad method. → The transformation of disorder to order (bcc a 2 to B2) and the new ternary compound L 12T i 25 Cr 8 Al 67 are considered in this work. - Abstract: The Ti-Al-Cr ternary system is one of the most important systems to studying the titanium alloys. Some experimental data of this ternary system are available and a few partial thermodynamic assessments are reported. However, no full thermodynamic descriptions were published. In this study, the previous work on the Ti-Al-Cr system and its related binary systems are reviewed. Based on the thermodynamic descriptions of the Ti-Al, Ti-Cr and Al-Cr systems and the ternary experimental data in literature, the Ti-Al-Cr ternary system is assessed by means of the Calphad method. Several isothermal sections from 1073 K to 1573 K and some invariant reactions are calculated, which are in good agreement with the most of the experimental results.

Cycloadditions to Epoxides Catalyzed by GroupIII-V Transition-Metal Complexes

KAUST Repository

D'Elia, Valerio

2015-05-25

Complexes of groupIII-V transition metals are gaining increasing importance as Lewis acid catalysts for the cycloaddition of dipolarophiles to epoxides. This review examines the latest reports, including homogeneous and heterogeneous applications. The pivotal step for the cycloaddition reactions is the ring opening of the epoxide following activation by the Lewis acid. Two modes of cleavage (C-C versus C-O) have been identified depending primarily on the substitution pattern of the epoxide, with lesser influence observed from the Lewis acid employed. The widely studied cycloaddition of CO2 to epoxides to afford cyclic carbonates (C-O bond cleavage) has been scrutinized in terms of catalytic efficiency and reaction mechanism, showing that unsophisticated complexes of groupIII-V transition metals are excellent molecular catalysts. These metals have been incorporated, as well, in highly performing, recyclable heterogeneous catalysts. Cycloadditions to epoxides with other dipolarophiles (alkynes, imines, indoles) have been conducted with scandium triflate with remarkable performances (C-C bond cleavage). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cycloadditions to Epoxides Catalyzed by GroupIII-V Transition-Metal Complexes

KAUST Repository

D'Elia, Valerio; Pelletier, Jeremie; Basset, Jean-Marie

2015-01-01

Complexes of groupIII-V transition metals are gaining increasing importance as Lewis acid catalysts for the cycloaddition of dipolarophiles to epoxides. This review examines the latest reports, including homogeneous and heterogeneous applications. The pivotal step for the cycloaddition reactions is the ring opening of the epoxide following activation by the Lewis acid. Two modes of cleavage (C-C versus C-O) have been identified depending primarily on the substitution pattern of the epoxide, with lesser influence observed from the Lewis acid employed. The widely studied cycloaddition of CO2 to epoxides to afford cyclic carbonates (C-O bond cleavage) has been scrutinized in terms of catalytic efficiency and reaction mechanism, showing that unsophisticated complexes of groupIII-V transition metals are excellent molecular catalysts. These metals have been incorporated, as well, in highly performing, recyclable heterogeneous catalysts. Cycloadditions to epoxides with other dipolarophiles (alkynes, imines, indoles) have been conducted with scandium triflate with remarkable performances (C-C bond cleavage). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Single Photon Counting UV Solar-Blind Detectors Using Silicon and III-Nitride Materials

Science.gov (United States)

Nikzad, Shouleh; Hoenk, Michael; Jewell, April D.; Hennessy, John J.; Carver, Alexander G.; Jones, Todd J.; Goodsall, Timothy M.; Hamden, Erika T.; Suvarna, Puneet; Bulmer, J.; Shahedipour-Sandvik, F.; Charbon, Edoardo; Padmanabhan, Preethi; Hancock, Bruce; Bell, L. Douglas

2016-01-01

Ultraviolet (UV) studies in astronomy, cosmology, planetary studies, biological and medical applications often require precision detection of faint objects and in many cases require photon-counting detection. We present an overview of two approaches for achieving photon counting in the UV. The first approach involves UV enhancement of photon-counting silicon detectors, including electron multiplying charge-coupled devices and avalanche photodiodes. The approach used here employs molecular beam epitaxy for delta doping and superlattice doping for surface passivation and high UV quantum efficiency. Additional UV enhancements include antireflection (AR) and solar-blind UV bandpass coatings prepared by atomic layer deposition. Quantum efficiency (QE) measurements show QE > 50% in the 100–300 nm range for detectors with simple AR coatings, and QE ≅ 80% at ~206 nm has been shown when more complex AR coatings are used. The second approach is based on avalanche photodiodes in III-nitride materials with high QE and intrinsic solar blindness. PMID:27338399

Site occupancies in ternary C15 ordered Laves phases

International Nuclear Information System (INIS)

Kotula, P.G.; Chu, F.; Thoma, D.J.; Mitchell, T.E.; Anderson, I.M.; Bentley, J.

1996-01-01

Site occupancies in three C15-structured AB 2 (X) Laves phases have been determined by Atom Location by CHanneling Enhanced MIcroanalysis (ALCHEMI). In NbCr 2 (V), the results were consistent with exclusive site occupancies of Nb for the A sublattice and Cr and V for the B sublattice. The B-site occupancy of V is not expected from atom size effects alone. In NbCr 2 (Ti), the results were consistent with Ti partitioning mostly to the A sites with some anti-site defects likely. In HfV 2 (Nb), the results were consistent with Nb partitioning between the A and B sites. The results of the ALCHEMI analyses of these ternary C15 Laves phase materials will be discussed with respect to previously determined phase diagrams and first-principles total energy and electronic structure calculations

Design and synthesis of ternary cobalt ferrite/graphene/polyaniline hierarchical nanocomposites for high-performance supercapacitors

Science.gov (United States)

Xiong, Pan; Huang, Huajie; Wang, Xin

2014-01-01

A ternary cobalt ferrite/graphene/polyaniline nanocomposite (CGP) is designed and fabricated via a facile two-step approach: cobalt ferrite nanoparticles dispersed on graphene sheets are achieved by a hydrothermal method, followed by coating with polyaniline (PANI) through in situ polymerization process. Electrochemical measurements demonstrate that the specific capacitance of the resulting ternary hybrid (CGP) is up to 1133.3 F g-1 at a scan rate of 1 mV s-1 and 767.7 F g-1 at a current density of 0.1 A g-1 using a three-electrode system, while 716.4 F g-1 at a scan rate of 1 mV s-1 and 392.3 F g-1 at a current density of 0.1 A g-1 using a two-electrode system, which are significantly higher than those of pure CoFe2O4, graphene and PANI, or binary CoFe2O4/graphene, CoFe2O4/PANI and graphene/PANI hybrids. In addition, over 96% of the initial capacitance can be retained after repeating test for 5000 cycles, demonstrating a high cycling stability. The extraordinary electrochemical performance of the ternary CGP nanocomposite can be attributed to its well-designed nanostructure and the synergistic effects of the individual components.

CAST search for sub-eV mass solar axions with $^{3}$He buffer gas

CERN Document Server

Aune, S; Belov, A; Borghi, S; Brauninger, H; Cantatore, G; Carmona, J M; Cetin, S A; Collar, J I; Dafni, T; Davenport, M; Eleftheriadis, C; Elias, N; Ezer, C; Fanourakis, G; Ferrer-Ribas, E; Friedrich, P; Galan, J; Garcia, J A; Gardikiotis, A; Gazis, E N; Geralis, T; Giomataris, I; Gninenko, S; Gomez, H; Gruber, E; Guthorl, T; Hartmann, R; Haug, F; Hasinoff, M D; Hoffmann, D H H; Iguaz, F J; Irastorza, I G; Jacoby, J; Jakovcic, K; Karuza, M; Konigsmann, K; Kotthaus, R; Krcmar, M; Kuster, M; Lakic, B; Laurent, J M; Liolios, A; Ljubicic, A; Lozza, V; Lutz, G; Luzon, G; Morales, J; Niinikoski, T; Nordt, A; Papaevangelou, T; Pivovaroff, M J; Raffelt, G; Rashba, T; Riege, H; Rodriguez, A; Rosu, M; Ruz, J; Savvidis, I; Silva, P S; Solanki, S.K; Stewart, L; Tomas, A; Tsagri, M; van Bibber, K; Vafeiadis, T; Villar, J A; Vogel, J K; Yildiz, S C; Zioutas, K

2011-01-01

The CERN Axion Solar Telescope (CAST) has extended its search for solar axions by using 3He as a buffer gas. At T=1.8 K this allows for larger pressure settings and hence sensitivity to higher axion masses than our previous measurements with 4He. With about 1 h of data taking at each of 252 different pressure settings we have scanned the axion mass range 0.39 eV < m_a < 0.64 eV. From the absence of excess X-rays when the magnet was pointing to the Sun we set a typical upper limit on the axion-photon coupling of g_ag < 2.3 x 10^{-10} GeV^{-1} at 95% CL, the exact value depending on the pressure setting. KSVZ axions are excluded at the upper end of our mass range, the first time ever for any solar axion search. In future we will extend our search to m_a < 1.15 eV, comfortably overlapping with cosmological hot dark matter bounds.

Adsorption of As(III), As(V) and Cu(II) on zirconium oxide immobilized alginate beads in aqueous phase.

Science.gov (United States)

Kwon, Oh-Hun; Kim, Jong-Oh; Cho, Dong-Wan; Kumar, Rahul; Baek, Seung Han; Kurade, Mayur B; Jeon, Byong-Hun

2016-10-01

A composite adsorbent to remove arsenite [As(III)], arsenate [As(V)], and copper [Cu(II)] from aqueous phase was synthesized by immobilizing zirconium oxide on alginate beads (ZOAB). The composition (wt%) of ZOAB (Zr-34.0; O-32.7; C-21.3; Ca-1.0) was confirmed by energy dispersive X-ray (EDX) analysis. Sorption studies were conducted on single and binary sorbate systems, and the effects of contact time, initial adsorbate concentration, and pH on the adsorption performance of ZOAB (pHPZC = 4.3) were monitored. The sorption process for As(III)/As(V) and Cu(II) reached an equilibrium state within 240 h and 24 h, respectively, with maximum sorption capacities of 32.3, 28.5, and 69.9 mg g(-1), respectively. The addition of Cu(II) was favorable for As(V) sorption in contrast to As(III). In the presence of 48.6 mg L(-1) Cu(II), the sorption capacity of As(V) increased from 1.5 to 3.8 mg g(-1) after 240 h. The sorption data for As(III)/As(V) and Cu(II) conformed the Freundlich and Langmuir isotherm models, respectively. The adsorption of As(III), As(V), and Cu(II) followed pseudo second order kinetics. The effect of arsenic species on Cu(II) sorption was insignificant. The results of present study demonstrated that the synthesized sorbent could be useful for the simultaneous removal of both anionic and cationic contaminants from wastewaters. Copyright © 2016 Elsevier Ltd. All rights reserved.

Enhancement of the photoelectric performance in inverted bulk heterojunction solid solar cell with inorganic nanocrystals

International Nuclear Information System (INIS)

Luan, Weiling; Zhang, Chengxi; Luo, Lingli; Yuan, Binxia; Jin, Lin; Kim, Yong-Sang

2017-01-01

Highlights: • Solid solar cells based on FeS_2 or PbS NCs showed power conversion efficiency (PCE) of 3.0% and 3.11%, respectively. • The FeS_2 NCs/polymer solar cells showed good time and thermal stability when exposed in air condition. • Ternary solid solar cells based on PbS NCs exhibited a higher short circuit current density (J_s_c). - Abstract: Nanocrystal/polymer solid solar cells have the advantages of low-cost, simple process, and flexible manufacture. In this work, ternary solid solar cells based on FeS_2 and PbS nanocrystals exhibited photovoltaic conversion efficiency of 3.0% and 3.1%, respectively. As a kind of semiconductor with optical absorption in the visible and near-infrared regions, FeS_2 nanocrystals matched well with the solar radiation spectrum. Furthermore, PbS Nanocrystals could increase the number of electrons, due to its multiple exciton effect. Additionally, the FeS_2 nanocrystals solar cells showed high stability, with 83.3% of its initial efficiency remained after 15 weeks of exposure in air, and kept good stable performance at 20–80 °C. The photovoltaic conversion efficiency fluctuation magnitudes were also found to be smaller than quantum-dot sensitized solar cell under the same conditions.

Changes in histoanatomical distribution of types I, III and V collagen promote adaptative remodeling in posterior tibial tendon rupture

Directory of Open Access Journals (Sweden)

Érika Satomi

2008-01-01

Full Text Available INTRODUCTION: Posterior tibial tendon dysfunction is a common cause of adult flat foot deformity, and its etiology is unknown. PURPOSE: In this study, we characterized the morphologic pattern and distribution of types I, III and V collagen in posterior tibial tendon dysfunction. METHOD: Tendon samples from patients with and without posterior tibial tendon dysfunction were stained by immunofluorescence using antibodies against types I, III and V collagen. RESULTS: Control samples showed that type V deposited near the vessels only, while surgically obtained specimens displayed type V collagen surrounding other types of collagen fibers in thicker adventitial layers. Type III collagen levels were also increased in pathological specimens. On the other hand, amounts of collagen type I, which represents 95% of the total collagen amount in normal tendon, were decreased in pathological specimens. CONCLUSION: Fibrillogenesis in posterior tibial tendon dysfunction is altered due to higher expression of types III and V collagen and a decreased amount of collagen type I, which renders the originating fibrils structurally less resistant to mechanical forces.

Construction of Tungsten Halogen, Pulsed LED, and Combined Tungsten Halogen-LED Solar Simulators for Solar Cell I-V Characterization and Electrical Parameters Determination

Directory of Open Access Journals (Sweden)

Anon Namin

2012-01-01

Full Text Available I-V characterization of solar cells is generally done under natural sunlight or solar simulators operating in either a continuous mode or a pulse mode. Simulators are classified on three features of irradiance, namely, spectral match with respect to air mass 1.5, spatial uniformity, and temporal stability. Commercial solar simulators use Xenon lamps and halogen lamps, whereas LED-based solar simulators are being developed. In this work, we build and test seven simulators for solar cell characterization, namely, one tungsten halogen simulator, four monochromatic (red, green, blue, and white LED simulators, one multicolor LED simulator, and one tungsten halogen-blue LED simulator. The seven simulators provide testing at nonstandard test condition. High irradiance from simulators is obtained by employing elevated supply voltage to tungsten halogen lamps and high pulsing voltages to LEDs. This new approach leads to higher irradiance not previously obtained from tungsten halogen lamps and LEDs. From I-V curves, electrical parameters of solar cell are made and corrected based on methods recommended in the IEC 60891 Standards. Corrected values obtained from non-STC measurements are in good agreement with those obtained from Class AAA solar simulator.

30 CFR 57.22204 - Main fan operation and inspection (I-A, II-A, III, and V-A mines).

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Main fan operation and inspection (I-A, II-A, III, and V-A mines). 57.22204 Section 57.22204 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... Main fan operation and inspection (I-A, II-A, III, and V-A mines). Main fans shall be— (a) Provided...

Reduction of As(V) to As(III) by commercial ZVI or As(0) with acid-treated ZVI

International Nuclear Information System (INIS)

Sun, Fenglong; Osseo-Asare, Kwadwo A.; Chen, Yongsheng; Dempsey, Brian A.

2011-01-01

Graphical abstract: Acid-treated ZVI (right) reduced As(V) to the less toxic As(0) while commercial ZVI reduced As(V) to As(III). There was no lag phase in either reaction when rigorously anoxic conditions were maintained. Highlights: ► Acid-treated ZVI reduced As(V) to the less toxic As(0). ► Commercial ZVI reduced As(V) to As(III), which was not released to solution. ► Magnetite/Fe(II) did not reduce As(V) even though the reaction is thermodynamically spontaneous. ► No lag phase was observed in any of the reactions, contrary to prior reports. ► Rigorously anoxic conditions seem necessary for observing these reactions. - Abstract: Zero-valent iron (ZVI) consists of an elemental iron core surrounded by a shell of corrosion products, especially magnetite. ZVI is used for in situ removal or immobilization of a variety of contaminants but the mechanisms for removal of arsenic remain controversial and the mobility of arsenic after reaction with ZVI is uncertain. These issues were addressed by separately studying reactions of As(V) with magnetite, commercial ZVI, and acid-treated ZVI. Strictly anoxic conditions were used. Adsorption of As(V) on magnetite was fast with pH dependence similar to previous reports using oxic conditions. As(V) was not reduced by magnetite and Fe(II) although the reaction is thermodynamically spontaneous. As(V) reactions with ZVI were also fast and no lag phase was observed which was contrary to previous reports. Commercial ZVI reduced As(V) to As(III) only when As(V) was adsorbed, i.e., for pH < 7. As(III) was not released to solution. Acid-treated ZVI reduced As(V) to As(0), shown using wet chemical analyses and XANES/EXAFS. Comparisons were drawn between reactivity of acid-treated ZVI and nano-ZVI; if true then acid-treated ZVI could provide similar reactive benefits at lower cost.

Ternary rare earth sulfide CaCe2S4: Synthesis and characterization of stability, structure, and photoelectrochemical properties in aqueous media

Science.gov (United States)

Sotelo, Paola; Orr, Melissa; Galante, Miguel Tayar; Hossain, Mohammad Kabir; Firouzan, Farinaz; Vali, Abbas; Li, Jun; Subramanian, Mas; Longo, Claudia; Rajeshwar, Krishnan; Macaluso, Robin T.

2018-06-01

A red-orange rare earth ternary chalcogenide, CaCe2S4, was prepared in powder form by solid-state synthesis. The structural details of this compound were determined by powder X-ray diffraction. The optical band gap of CaCe2S4 was determined by diffuse reflectance spectroscopy (DRS) to be 2.1 eV, consistent with the observed red-orange color. Quantitative colorimetry measurements also support the observed color and band gap of CaCe2S4. Both direct and indirect optical transitions were gleaned from Tauc analyses of the DRS data. Photoelectrochemistry experiments on CaCe2S4 films showed n-type semiconductor behavior. Analyses of these data via the Butler-Gärtner model afforded a flat-band potential of - 0.33 V (vs. Ag/AgCl/KCl 4 M) in pH 9 aqueous sulfite electrolyte. The potential and limitations of this material for solar water splitting and photocatalytic environmental remediation (e.g., dye photodegradation) are finally presented against the backdrop of its photoelectrochemical stability and surface hole transfer kinetics in aqueous electrolytes.

Experimental investigation of the Ag–Bi–I ternary system and thermodynamic properties of the ternary phases

International Nuclear Information System (INIS)

Mashadieva, Leyla F.; Aliev, Ziya S.; Shevelkov, Andrei V.; Babanly, Mahammad B.

2013-01-01

Highlights: ► The self-consistent phase diagram of the Ag–Bi–I system is constructed. ► Ag 2 BiI 5 and AgBi 2 I 7 are the only ternary phases of the system. ► Standard thermodynamic functions of formation and the standard entropies of Ag 2 BiI 5 and AgBi 2 I 7 are calculated. - Abstract: The phase equilibriums in the Ag–Bi–I ternary system and thermodynamic properties of the ternary phases were experimentally determined by using DTA and XRD techniques and EMF measurements with the Ag 4 RbI 5 solid electrolyte. According to the obtained experimental results, the polythermal sections of the ternary phase diagram, its isothermal section at 300 K as well as the projection of the liquids surface have been revised. The fields of the primary crystallization and types and coordinates of nonvariant and monovariant equilibriums were determined. The partial molar functions of silver iodide and silver in the alloys as well as the standard thermodynamic functions of formation and the standard entropies of Ag 2 BiI 5 and AgBi 2 I 7 were calculated based on EMF measurements.

Relationship between open-circuit voltage in Cu(In,Ga)Se2 solar cell and peak position of (220/204) preferred orientation near its absorber surface

International Nuclear Information System (INIS)

Chantana, J.; Minemoto, T.; Watanabe, T.; Teraji, S.; Kawamura, K.

2013-01-01

Cu(In,Ga)Se 2 (CIGS) absorbers with various Ga/III, Ga/(In+Ga), profiles are prepared by the so-called “multi-layer precursor method” using multi-layer co-evaporation of material sources. It is revealed that open-circuit voltage (V OC ) of CIGS solar cell is primarily dependent on averaged Ga/III near the surface of its absorber. This averaged Ga/III is well predicted by peak position of (220/204) preferred orientation of CIGS film near its surface investigated by glancing-incidence X-ray diffraction with 0.1° incident angle. Finally, the peak position of (220/204) preferred orientation is proposed as a measure of V OC before solar cell fabrication

David Adler Lectureship Award Talk: III-V Semiconductor Nanowires on Silicon for Future Devices

Science.gov (United States)

Riel, Heike

Bottom-up grown nanowires are very attractive materials for direct integration of III-V semiconductors on silicon thus opening up new possibilities for the design and fabrication of nanoscale devices for electronic, optoelectronic as well as quantum information applications. Template-Assisted Selective Epitaxy (TASE) allows the well-defined and monolithic integration of complex III-V nanostructures and devices on silicon. Achieving atomically abrupt heterointerfaces, high crystal quality and control of dimension down to 1D nanowires enabled the demonstration of FETs and tunnel devices based on In(Ga)As and GaSb. Furthermore, the strong influence of strain on nanowires as well as results on quantum transport studies of InAs nanowires with well-defined geometry will be presented.

III-V group compound semiconductor light-emitting element having a doped tantalum barrier layer

International Nuclear Information System (INIS)

Oanna, Y.; Ozawa, N.; Yamashita, M.; Yasuda, N.

1984-01-01

Disclosed is a III-V Group compound semiconductor light-emitting element having a III-V Group compound semiconductor body with a p-n junction and including a p-type layer involved in forming the p-n junction; and a multi-layer electrode mounted on the p-type layer of the semiconductor body. The electrode comprises a first layer of gold alloy containing a small amount of beryllium or zinc and formed in direct contact with the p-type layer of the semiconductor body and an uppermost layer formed of gold or aluminum. A tantalum layer doped with carbon, nitrogen and/or oxygen is formed between the first layer and the uppermost layer by means of vacuum vapor deposition

DX centers in III-V semiconductors under hydrostatic pressure

International Nuclear Information System (INIS)

Wolk, J.A.

1992-11-01

DX centers are deep level defects found in some III-V semiconductors. They have persistent photoconductivity and large difference between thermal and optical ionization energies. Hydrostatic pressure was used to study microstructure of these defects. A new local vibrational mode (LVM) was observed in hydrostatically stressed, Si-doped GaAs. Corresponding infrared absorption peak is distinct from the Si Ga shallow donor LVM peak, which is the only other LVM peak observed in our samples, and is assigned to the Si DX center. Analysis of the relative intensities of the Si DX LVM and the Si shallow donor LVM peaks, combined with Hall effect and resistivity indicate that the Si DX center is negatively charged. Frequency of this new mode provides clues to the structure of this defect. A pressure induced deep donor level in S-doped InP was also discovered which has the properties of a DX center. Pressure at which the new defect becomes more stable than the shallow donor is 82 kbar. Optical ionization energy and energy dependence of the optical absorption cross section was measured for this new effect. Capture barrier from the conduction band into the DX state were also determined. That DX centers can be formed in InP by pressure suggests that DX states should be common in n-type III-V semiconductors. A method is suggested for predicting under what conditions these defects will be the most stable form of the donor impurity

Synthesis and Characterization of Novel Ternary and Quaternary Alkali Metal Thiophosphates

KAUST Repository

Alahmary, Fatimah S.

2014-05-01

The ongoing development of nonlinear optical (NLO) crystals such as coherent mid-IR sources focuses on various classes of materials such as ternary and quaternary metal chalcophosphates. In case of thiophosphates, the connection between PS4-tetrahedral building blocks and metals gives rise to a broad structural variety where approximately one third of all known ternary (A/P/S) and quaternary (A/M/P/S) (A = alkali metal, M = metal) structures are acentric and potential nonlinear optical materials. The molten alkali metal polychalcophosphate fluxes are a well-established method for the synthesis of new ternary and quaternary thiophosphate and selenophosphate compounds. It has been a wide field of study and investigation through the last two decades. Here, the flux method is used for the synthesis of new quaternary phases containing Rb, Ag, P and S. Four new alkali metal thiophosphates, Rb4P2S10, RbAg5(PS4), Rb2AgPS4 and Rb3Ag9(PS4)4, have been synthesized successfully from high purity elements and binary starting materials. The new compounds were characterized by single crystal and powder X-ray diffraction, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), ultraviolet-visible (UV-VIS), Raman spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). These compounds show interesting structural variety and physical properties. The crystal structures feature 3D anionic framework built up of PS4 tetrahedral units and charge balanced by Ag and alkali metal cations. All prepared compounds are semiconductors with band gap between 2.3 eV to 2.6 eV and most of them are thermally stable up to 600ºC.

The ternary post-transition metal carbodiimide SrZn(NCN)2

International Nuclear Information System (INIS)

Corkett, Alex J.; Konze, Philipp M.; Dronskowski, Richard

2017-01-01

SrZn(NCN) 2 , the first example of a ternary post-transition metal carbodiimide, was prepared by a solid-state metathesis reaction. The crystal structure was solved from PXRD data and found to adopt the orthorhombic (Cmcm) BaZnSO structure, a high symmetry modification of that expressed by the oxide analogue SrZnO 2 . Locally, SrZn(NCN) 2 features ZnN 4 tetrahedra and SrN 6 trigonal prisms similar to those in quarternary LiSr 2 M(NCN) 4 (M = Al 3+ and Ga 3+ ) phases, however, the overall topologies are distinct with single chains in the former and double chains in the latter. Electronic structure calculations indicate an indirect bandgap of about 2.95 eV in SrZn(NCN) 2 , slightly lower than the experimentally observed bandgap of 3.4 eV in SrZnO 2 and consistent with a greater degree of covalency. The structural similarities between SrZn(NCN) 2 and oxychalcogenide analogues highlight the pseudochalcogenide character of NCN 2- and suggest that the title compound may serve as a template for accessing novel ternary carbodiimides featuring tetrahedrally coordinated transition metals. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Spectroscopic characterization of III-V semiconductor nanomaterials

Science.gov (United States)

Crankshaw, Shanna Marie

III-V semiconductor materials form a broad basis for optoelectronic applications, including the broad basis of the telecom industry as well as smaller markets for high-mobility transistors. In a somewhat analogous manner as the traditional silicon logic industry has so heavily depended upon process manufacturing development, optoelectronics often relies instead on materials innovations. This thesis focuses particularly on III-V semiconductor nanomaterials, detailed characterization of which is invaluable for translating the exhibited behavior into useful applications. Specifically, the original research described in these thesis chapters is an investigation of semiconductors at a fundamental materials level, because the nanostructures in which they appear crystallize in quite atypical forms for the given semiconductors. Rather than restricting the experimental approaches to any one particular technique, many different types of optical spectroscopies are developed and applied where relevant to elucidate the connection between the crystalline structure and exhibited properties. In the first chapters, for example, a wurtzite crystalline form of the prototypical zincblende III-V binary semiconductor, GaAs, is explored through polarization-dependent Raman spectroscopy and temperature-dependent photoluminescence, as well as second-harmonic generation (SHG). The altered symmetry properties of the wurtzite crystalline structure are particularly evident in the Raman and SHG polarization dependences, all within a bulk material realm. A rather different but deeply elegant aspect of crystalline symmetry in GaAs is explored in a separate study on zincblende GaAs samples quantum-confined in one direction, i.e. quantum well structures, whose quantization direction corresponds to the (110) direction. The (110) orientation modifies the low-temperature electron spin relaxation mechanisms available compared to the usual (001) samples, leading to altered spin coherence times explored

Cu{sub 2}ZnSnS{sub 4} thin film solar cells from electroplated precursors: Novel low-cost perspective

Energy Technology Data Exchange (ETDEWEB)

Ennaoui, A. [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Solar Energy Division, Glienickerstrasse 100, D-14109 Berlin (Germany)], E-mail: ennaoui@helmholtz-berlin.de; Lux-Steiner, M.; Weber, A.; Abou-Ras, D.; Koetschau, I.; Schock, H.-W. [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Solar Energy Division, Glienickerstrasse 100, D-14109 Berlin (Germany); Schurr, R.; Hoelzing, A.; Jost, S.; Hock, R. [Crystallography and Structural Physics, University of Erlangen-Nuernberg, Staudtstrasse 3, D-91058 Erlangen (Germany); Voss, T.; Schulze, J.; Kirbs, A. [Atotech Deutschland GmbH, Erasmusstr. 20, D-10553 Berlin (Germany)

2009-02-02

Thin-film solar cells based on Cu{sub 2}ZnSnS{sub 4} (CZTS) absorbers were fabricated successfully by solid-state reaction in H{sub 2}S atmosphere of electrodeposited Cu-Zn-Sn precursors. These ternary alloys were deposited in one step from a cyanide-free alkaline electrolyte containing Cu(II), Zn (II) and Sn (IV) metal salts on Mo-coated glass substrates. The solar cell was completed by a chemical bath-deposited CdS buffer layer and a sputtered i-ZnO/ZnO:Al bilayer. The best solar cell performance was obtained with Cu-poor samples. A total area (0.5 cm{sup 2}) efficiency of 3.4% is achieved (V{sub oc} = 563 mV, j{sub sc} = 14.8 mA/cm{sup 2}, FF = 41%) with a maximum external quantum efficiency (EQE) of 80%. The estimated band-gap energy from the external quantum efficiency (EQE) measurements is about 1.54 eV. Electron backscatter-diffraction maps of cross-section samples revealed CZTS grain sizes of up to 10 {mu}m. Elemental distribution maps of the CZTS absorber show Zn-rich precipitates, probably ZnS, and a Zn-poor region, presumably Cu{sub 2}SnS{sub 3}, close to the interface Mo/CZTS.

Ternary complex formation at mineral/solution interfaces

International Nuclear Information System (INIS)

Leckie, J.O.

1995-01-01

Adsorption of trace concentrations of radionuclides and heavy metals from aqueous solution is dependent on pH, absorbent and adsorbate concentration, and speciation of the metal in solution. In particular, complexation of metal ions by organic and inorganic ligands can dramatically alter adsorption behavior compared to ligand-free systems. The presence of complexing ligands can cause the formation of ''metal like'' or ''ligand like'' ternary surface complexes depending on whether adsorption of the ternary complex increases or decreases with increasing pH, respectively. Examples of ternary surface complexes behaving ''metal like'' include uranyl-EDTA surface complexes on goethite, neptunyl-EDTA surface complexes on hematite and neptunyl-humic surface complexes on gibbsite. Examples of ''ligand like'' ternary surface complexes include uranyl-carbonato and neptunyl-carbonato surface complexes on iron oxides. The effects of complex solutions and multimineralic systems are discussed. (authors). 39 refs., 16 figs., 8 tabs

QUIET-TIME SUPRATHERMAL (∼0.1–1.5 keV) ELECTRONS IN THE SOLAR WIND

Energy Technology Data Exchange (ETDEWEB)

Tao, Jiawei; Wang, Linghua; Zong, Qiugang; He, Jiansen; Tu, Chuanyi [School of Earth and Space Science, Peking University, Beijing 100871 (China); Li, Gang [Department of Physics and CSPAR, University of Alabama in Huntsville, Alabama 35899 (United States); Salem, Chadi S.; Bale, Stuart D. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Wimmer-Schweingruber, Robert F., E-mail: wanglhwang@gmail.com [Institute for Experimental and Applied Physics, University of Kiel, Leibnizstrasse 11, D-24118 Kiel (Germany)

2016-03-20

We present a statistical survey of the energy spectrum of solar wind suprathermal (∼0.1–1.5 keV) electrons measured by the WIND 3DP instrument at 1 AU during quiet times at the minimum and maximum of solar cycles 23 and 24. After separating (beaming) strahl electrons from (isotropic) halo electrons according to their different behaviors in the angular distribution, we fit the observed energy spectrum of both strahl and halo electrons at ∼0.1–1.5 keV to a Kappa distribution function with an index κ and effective temperature T{sub eff}. We also calculate the number density n and average energy E{sub avg} of strahl and halo electrons by integrating the electron measurements between ∼0.1 and 1.5 keV. We find a strong positive correlation between κ and T{sub eff} for both strahl and halo electrons, and a strong positive correlation between the strahl n and halo n, likely reflecting the nature of the generation of these suprathermal electrons. In both solar cycles, κ is larger at solar minimum than at solar maximum for both strahl and halo electrons. The halo κ is generally smaller than the strahl κ (except during the solar minimum of cycle 23). The strahl n is larger at solar maximum, but the halo n shows no difference between solar minimum and maximum. Both the strahl n and halo n have no clear association with the solar wind core population, but the density ratio between the strahl and halo roughly anti-correlates (correlates) with the solar wind density (velocity)

9.0% power conversion efficiency from ternary all-polymer solar cells

NARCIS (Netherlands)

Li, Z.; Xu, X.; Zhang, W.; Meng, X.; Genene, Z.; Ma, W.; Mammo, W.; Yartsev, A.; Andersson, M.; Janssen, R.A.J.; Wang, E.

2017-01-01

Integration of a third component into a single-junction polymer solar cell (PSC) is regarded as an attractive strategy to enhance the performance of PSCs. Although binary all-polymer solar cells (all-PSCs) have recently emerged with compelling power conversion efficiencies (PCEs), the PCEs of

Equilibrium phase diagram of the Ag-Au-Pb ternary system

International Nuclear Information System (INIS)

Hassam, S.; Bahari, Z.

2005-01-01

The phase diagram of the ternary system Ag-Au-Pb has been established using differential thermal analysis and X-ray powder diffraction analysis. Four vertical sections were studied: X Pb = 0.40, X Au /X Pb = 1/3, X Ag /X Au = 4/1 and X Ag /X Au = 1/1. Two ternary transitory peritectics and one ternary eutectic were characterized. A schematic representation of the ternary equilibria is given

Relationship between open-circuit voltage in Cu(In,Ga)Se{sub 2} solar cell and peak position of (220/204) preferred orientation near its absorber surface

Energy Technology Data Exchange (ETDEWEB)

Chantana, J., E-mail: jakapan@fc.ritsumei.ac.jp; Minemoto, T. [Department of Electrical and Electronic Engineering, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577 (Japan); Watanabe, T.; Teraji, S.; Kawamura, K. [Environment and Energy Research Center, Nitto Denko Corporation, 2-8 Yamadaoka, Suita, Osaka 565-0871 (Japan)

2013-11-25

Cu(In,Ga)Se{sub 2} (CIGS) absorbers with various Ga/III, Ga/(In+Ga), profiles are prepared by the so-called “multi-layer precursor method” using multi-layer co-evaporation of material sources. It is revealed that open-circuit voltage (V{sub OC}) of CIGS solar cell is primarily dependent on averaged Ga/III near the surface of its absorber. This averaged Ga/III is well predicted by peak position of (220/204) preferred orientation of CIGS film near its surface investigated by glancing-incidence X-ray diffraction with 0.1° incident angle. Finally, the peak position of (220/204) preferred orientation is proposed as a measure of V{sub OC} before solar cell fabrication.

Ternary networks reliability and Monte Carlo

CERN Document Server

Gertsbakh, Ilya; Vaisman, Radislav

2014-01-01

Ternary means “based on three”. This book deals with reliability investigations of  networks whose components subject to failures can be in three states –up, down and middle (mid), contrary to traditionally considered networks  having only binary (up/down) components. Extending binary case to ternary allows to consider more realistic and flexible models for communication, flow and supply networks.

Ternary fission induced by polarized neutrons

Directory of Open Access Journals (Sweden)

Gönnenwein Friedrich

2013-12-01

Full Text Available Ternary fission of (e,e U- and Pu- isotopes induced by cold polarized neutrons discloses some new facets of the process. In the so-called ROT effect shifts in the angular distributions of ternary particles relative to the fission fragments show up. In the so-called TRI effect an asymmetry in the emission of ternary particles relative to a plane formed by the fragment momentum and the spin of the neutron appear. The two effects are shown to be linked to the components of angular momentum perpendicular and parallel to the fission axis at the saddle point of fission. Based on theoretical models the spectroscopic properties of the collective transitional states at the saddle point are inferred from experiment.

{sup 5}He ternary fission yields of {sup 252}Cf and {sup 235}U(n,f)

Energy Technology Data Exchange (ETDEWEB)

Hwang, J. K. [Department of Physics, Vanderbilt University, Nashville, Tennessee 37235 (United States); Ramayya, A. V. [Department of Physics, Vanderbilt University, Nashville, Tennessee 37235 (United States); Hamilton, J. H. [Department of Physics, Vanderbilt University, Nashville, Tennessee 37235 (United States); Beyer, C. J. [Department of Physics, Vanderbilt University, Nashville, Tennessee 37235 (United States); Kormicki, J. [Department of Physics, Vanderbilt University, Nashville, Tennessee 37235 (United States); Zhang, X. Q. [Department of Physics, Vanderbilt University, Nashville, Tennessee 37235 (United States); Rodin, A. [Flerov Laboratory for Nuclear Reactions, Joint Institute for Nuclear Research, Dubna, Russia (Russian Federation); Formichev, A. [Flerov Laboratory for Nuclear Reactions, Joint Institute for Nuclear Research, Dubna, Russia (Russian Federation); Kliman, J. [Flerov Laboratory for Nuclear Reactions, Joint Institute for Nuclear Research, Dubna, Russia (Russian Federation); Krupa, L. [Flerov Laboratory for Nuclear Reactions, Joint Institute for Nuclear Research, Dubna, Russia (Russian Federation)] (and others)

2000-04-01

The relative {sup 4}He and {sup 5}He ternary fission yields were determined from a careful analysis of the energy distribution of {alpha} spectra from a new measurement with a {sup 252}Cf source and from published data on {sup 252}Cf and {sup 235}U(n,f). The kinetic energies of the {sup 5}He and {sup 4}He ternary particles were found to be approximately 11 and 16 MeV, respectively. {sup 5}He particles contribute 10-20 % to the total alpha yield with the remainder originating from {sup 4}He accompanied fission. (c) 2000 The American Physical Society.

NREL, CSEM Jointly Set New Efficiency Record with Dual-Junction Solar Cell

Energy Technology Data Exchange (ETDEWEB)

2016-01-01

Scientists set a new world record for converting non-concentrated sunlight into electricity using a dual-junction III-V/Si solar cell. National Renewable Energy Laboratory (NREL) and Swiss Center for Electronics and Microtechnology (CSEM) scientists have collaborated to create a novel tandem solar cell that operates at 29.8% conversion efficiency under non-concentrator (1-sun) conditions. In comparison, the 1-sun efficiency of a silicon (Si) single-junction solar cell is probably still a few years away from converging on its practical limit of about 26%.

Cu2O-based solar cells using oxide semiconductors

International Nuclear Information System (INIS)

Minami, Tadatsugu; Nishi, Yuki; Miyata, Toshihiro

2016-01-01

We describe significant improvements of the photovoltaic properties that were achieved in Al-doped ZnO (AZO)/n-type oxide semiconductor/p-type Cu 2 O heterojunction solar cells fabricated using p-type Cu 2 O sheets prepared by thermally oxidizing Cu sheets. The multicomponent oxide thin film used as the n-type semiconductor layer was prepared with various chemical compositions on non-intentionally heated Cu 2 O sheets under various deposition conditions using a pulsed laser deposition method. In Cu 2 O-based heterojunction solar cells fabricated using various ternary compounds as the n-type oxide thin-film layer, the best photovoltaic performance was obtained with an n-ZnGa 2 O 4 thin-film layer. In most of the Cu 2 O-based heterojunction solar cells using multicomponent oxides composed of combinations of various binary compounds, the obtained photovoltaic properties changed gradually as the chemical composition was varied. However, with the ZnO-MgO and Ga 2 O 3 -Al 2 O 3 systems, higher conversion efficiencies (η) as well as a high open circuit voltage (V oc ) were obtained by using a relatively small amount of MgO or Al 2 O 3 , e.g., (ZnO) 0.91 –(MgO) 0.09 and (Ga 2 O 3 ) 0.975 –(Al 2 O 3 ) 0.025 , respectively. When Cu 2 O-based heterojunction solar cells were fabricated using Al 2 O 3 –Ga 2 O 3 –MgO–ZnO (AGMZO) multicomponent oxide thin films deposited with metal atomic ratios of 10, 60, 10 and 20 at.% for the Al, Ga, Mg and Zn, respectively, a high V oc of 0.98 V and an η of 4.82% were obtained. In addition, an enhanced η and an improved fill factor could be achieved in AZO/n-type multicomponent oxide/p-type Cu 2 O heterojunction solar cells fabricated using Na-doped Cu 2 O (Cu 2 O:Na) sheets that featured a resistivity controlled by optimizing the post-annealing temperature and duration. Consequently, an η of 6.25% and a V oc of 0.84 V were obtained in a MgF 2 /AZO/n-(Ga 2 O 3 –Al 2 O 3 )/p-Cu 2 O:Na heterojunction solar cell fabricated using

Solar generation: a blueprint for growing the PV market

International Nuclear Information System (INIS)

Cameron, M.; Stierstorfer, J.; Teske, S.; Aubrey, C.

2001-01-01

The rapid growth of the solar electricity market is discussed. The European Photovoltaic Industry Association and Greenpeace have recently collaborated on a long-term forecast of the global solar electricity market up to 2020 with predictions up to 2040; the conclusions from their joint study are the subject of this article. The paper is presented under the main sub-headings of (i) background to the collaboration; (ii) the Greenpeace perspective; (iii) the impact of solar electricity in the lives of consumers and job-seekers born today; (iv) solar generation-methods and assumptions (v) market growth rates; (vi) electricity generation; (vii) carbon dioxide emissions; (viii) projection to 2040; (ix) key results of the EPIA/Greenpeace analysis; (x) solar electricity as a vehicle for job creation and (xi) creating the conditions for optimizing the impact of solar electricity on future generations. A chart shows solar electricity job creation potential 2000-2020

High-resolution infrared spectroscopy of the interacting v₉, v₅ + v₆ and 3v₆ levels of CH₂⁷⁹BrF

DEFF Research Database (Denmark)

Visinoni, R.; Baldacci, A.; Larsen, R. Wugt

2011-01-01

order a- and b- and c-type Coriolis terms. A detailed analysis of the rotational structure yields a set of accurate upper-state parameters up to quartic distortion terms for v(9) and v(5) + v(6). In addition, spectroscopic information about the dark ternary overtone of v(6) has been obtained. (C) 2011...

Complexation of the actinides (III, IV and V) with organic acids

International Nuclear Information System (INIS)

Leguay, S.

2012-01-01

A thorough knowledge of the chemical properties of actinides is now required in a wide variety of fields: extraction processes involved in spent fuel reprocessing, groundwater in the vicinity of radioactive waste packages, environmental and biological media in the case of accidental release of radionuclides. In this context, the present work has been focused on the complexation of Am(III), Cm(III), Cf(III), Pu(IV) and Pa(V) with organic ligands: DTPA, NTA and citric acid. The complexation of pentavalent protactinium with citric and nitrilotriacetic acids was studied using liquid-liquid extraction with the element at tracer scale (C Pa ≤ 10 -10 M). The order and the mean charge of each complex were determined from the analysis of the systematic variations of the distribution coefficient of Pa(V) as function of ligand and proton concentration. Then, the apparent formation constants related of the so-identified complexes were calculated. The complexation of trivalent actinides with DTPA was studied by fluorescence spectroscopy (TRLFS) and capillary electrophoresis (CE-ICP-MS). The coexistence of the mono-protonated and non-protonated complexes (AnHDTPA - and AnDTPA 2- ) in acidic media (1.5 ≤ pH ≤ 3.5) was shown unambiguously. Literature data have been reinterpreted by taking into account both complexes and a consistent set of formation constants of An(III)-DTPA has been obtained. The experimental study was completed by theoretical calculations (DFT) on Cm-DTPA system. The coordination geometry of Cm in CmDTPA 2- and CmHDTPA - including water molecules in the first coordination sphere has been determined as well as interatomic distances. Finally, a study on the complexation of Pu(IV) with DTPA was initiated in order to more closely mimic physiological conditions. A three-step approach was proposed to avoid plutonium hydrolysis: i/ complexation of Pu(IV) with (NTA) in order to protect Pu(IV) from hydrolysis (at low pH) ii/ increase of pH toward neutral conditions

Electrically driven hybrid Si/III-V Fabry-Pérot lasers based on adiabatic mode transformers.

Science.gov (United States)

Ben Bakir, B; Descos, A; Olivier, N; Bordel, D; Grosse, P; Augendre, E; Fulbert, L; Fedeli, J M

2011-05-23

We report the first demonstration of an electrically driven hybrid silicon/III-V laser based on adiabatic mode transformers. The hybrid structure is formed by two vertically superimposed waveguides separated by a 100-nm-thick SiO2 layer. The top waveguide, fabricated in an InP/InGaAsP-based heterostructure, serves to provide optical gain. The bottom Si-waveguides system, which supports all optical functions, is constituted by two tapered rib-waveguides (mode transformers), two distributed Bragg reflectors (DBRs) and a surface-grating coupler. The supermodes of this hybrid structure are controlled by an appropriate design of the tapers located at the edges of the gain region. In the middle part of the device almost all the field resides in the III-V waveguide so that the optical mode experiences maximal gain, while in regions near the III-V facets, mode transformers ensure an efficient transfer of the power flow towards Si-waveguides. The investigated device operates under quasi-continuous wave regime. The room temperature threshold current is 100 mA, the side-mode suppression ratio is as high as 20 dB, and the fiber-coupled output power is ~7 mW.

78 FR 77447 - California Wind Energy Association, First Solar, Inc. v. California Independent System Operator...

Science.gov (United States)

2013-12-23

... Energy Association, First Solar, Inc. v. California Independent System Operator Corporation, Southern...), California Wind Energy Association and First Solar, Inc. (collectively, Complainants) filed a formal complaint against the California Independent System Operator Corporation (CAISO) and Southern California...

Description of light charged particle emission in ternary fission

International Nuclear Information System (INIS)

Andreev, A. V.; Adamian, G. G.; Antonenko, N. V.; Kuklin, S. N.; Scheid, W.

2010-01-01

We consider the motion of three fragments starting from the scission point of ternary system. In the alpha-accompanied ternary fission the initial conditions are not the free parameters and determined by minimization of potential energy at scission point. In the trajectory calculations the angular distribution and mean value of the kinetic energy of the alpha-particles are well described in the spontaneous ternary fission of 252 Cf. In the Be- and C-accompanied ternary fission we found that the emission of the third particle occurs from one of the heavy fragments after their separation. (authors)

InP solar cell with window layer

Science.gov (United States)

Jain, Raj K. (Inventor); Landis, Geoffrey A. (Inventor)

1994-01-01

The invention features a thin light transmissive layer of the ternary semiconductor indium aluminum arsenide (InAlAs) as a front surface passivation or 'window' layer for p-on-n InP solar cells. The window layers of the invention effectively reduce front surface recombination of the object semiconductors thereby increasing the efficiency of the cells.

Evaluation of ternary blended cements for use in transportation concrete structures

Science.gov (United States)

Gilliland, Amanda Louise

This thesis investigates the use of ternary blended cement concrete mixtures for transportation structures. The study documents technical properties of three concrete mixtures used in federally funded transportation projects in Utah, Kansas, and Michigan that used ternary blended cement concrete mixtures. Data were also collected from laboratory trial batches of ternary blended cement concrete mixtures with mixture designs similar to those of the field projects. The study presents the technical, economic, and environmental advantages of ternary blended cement mixtures. Different barriers of implementation for using ternary blended cement concrete mixtures in transportation projects are addressed. It was concluded that there are no technical, economic, or environmental barriers that exist when using most ternary blended cement concrete mixtures. The technical performance of the ternary blended concrete mixtures that were studied was always better than ordinary portland cement concrete mixtures. The ternary blended cements showed increased durability against chloride ion penetration, alkali silica reaction, and reaction to sulfates. These blends also had less linear shrinkage than ordinary portland cement concrete and met all strength requirements. The increased durability would likely reduce life cycle costs associated with concrete pavement and concrete bridge decks. The initial cost of ternary mixtures can be higher or lower than ordinary portland cement, depending on the supplementary cementitious materials used. Ternary blended cement concrete mixtures produce less carbon dioxide emissions than ordinary portland cement mixtures. This reduces the carbon footprint of construction projects. The barriers associated with implementing ternary blended cement concrete for transportation projects are not significant. Supplying fly ash returns any investment costs for the ready mix plant, including silos and other associated equipment. State specifications can make

MSW regeneration of solar and supernova V in the earth

International Nuclear Information System (INIS)

Cribier, M.; Lagage, P.O.; Rich, J.; Spiro, M.; Vignaud, D.

1987-01-01

We discuss the MSW (Mikheyev-Smirnov-Wolfenstein) effect for different radiochemical and real-time neutrino experiments taking into account the effects of the passage through the earth for solar and supernova neutrinos. We emphasize that V e regeneration in the earth can lead to measurable increases in counting rates and to a time dependent V e energy spectrum. Such observations would verify the presence of the MSW effect and lead to a restriction on the allowed values of neutrino mass differences and mixing angles

THE 'TWIN-CME' SCENARIO AND LARGE SOLAR ENERGETIC PARTICLE EVENTS IN SOLAR CYCLE 23

Energy Technology Data Exchange (ETDEWEB)

Ding, Liuguan; Jiang, Yong [College of Math and Physics, Nanjing University of Information Science and Technology, Nanjing, Jiangsu 210044 (China); Zhao, Lulu; Li, Gang, E-mail: gang.li@uah.edu [Department of Physics and CSPAR, University of Alabama in Huntsville, AL 35899 (United States)

2013-01-20

Energetic particles in large solar energetic particle (SEP) events are a major concern for space weather. Recently, Li et al. proposed a 'twin-CME' scenario for ground-level events. Here we extend that study to large SEP events in solar cycle 23. Depending on whether preceding coronal mass ejections (CMEs) within 9 hr exist and whether ions >10 MeV nucleon{sup -1} exceed 10 pfu, we categorize fast CMEs with speed >900 km s{sup -1} and width >60 Degree-Sign from the western hemisphere source regions into four groups: groups I and II are 'twin' and single CMEs that lead to large SEPs; groups III and IV are 'twin' and single CMEs that do not lead to large SEPs. The major findings of this paper are: first, large SEP events tend to be 'twin-CME' events. Of 59 western large SEP events in solar cycle 23, 43 are 'twin-CME' (group I) events and 16 are single-CME (group II) events. Second, not all 'twin CMEs' produced large SEPs: 28 twin CMEs did not produce large SEPs (group III events). Some of them produced excesses of particles up to a few MeV nucleon{sup -1}. Third, there were 39 single fast CMEs that did not produce SEPs (group IV events). Some of these also showed an excess of particles up to a few MeV nucleon{sup -1}. For all four groups of events, we perform statistical analyses on properties such as the angular width, the speed, the existence of accompanying metric type II radio bursts, and the associated flare class for the main CMEs and the preceding CMEs.

Ternary system of dihydroartemisinin with hydroxypropyl-β-cyclodextrin and lecithin: simultaneous enhancement of drug solubility and stability in aqueous solutions.

Science.gov (United States)

Wang, Dan; Li, Haiyan; Gu, Jingkai; Guo, Tao; Yang, Shuo; Guo, Zhen; Zhang, Xueju; Zhu, Weifeng; Zhang, Jiwen

2013-09-01

The purpose of this study was to simultaneously improve the solubility and stability of dihydroartemisinin (DHA) in aqueous solutions by a ternary cyclodextrin system comprised of DHA, hydroxypropyl-β-cyclodextrin (HP-β-CD) and a third auxiliary substance. Solubility and phase solubility studies were carried out to evaluate the solubilizing efficiency of HP-β-CD in association with various auxiliary substances. Then, the solid binary (DHA-HP-β-CD or DHA-lecithin) and ternary systems were prepared and characterized by Fourier transform infrared (FT-IR), differential scanning calorimetry (DSC) and power X-ray diffraction (PXRD). The effect of the ternary system on the solubility, dissolution and stability of DHA in aqueous solutions was also investigated. As a result, the soybean lecithin was found to be the most promising third component in terms of solubility enhancement. For the solid characterization, the disappearance of the drug crystallinity indicated the formation of new solid phases, implicating the formation of the ternary system. The dissolution rate of the solid ternary system was much faster than that of the drug alone and binary systems. Importantly, compared with binary systems, the ternary system showed a significant improvement in the stability of DHA in Hank's balanced salt solutions (pH 7.4). The solubility and stability of DHA in aqueous solutions were simultaneously enhanced by the ternary system, which might be attributed to the possible formation of a ternary complex. For the ternary interactions, results of molecular docking studies further indicated that the lecithin covered the top of the wide rim of HP-β-CD and surrounded around the peroxide bridging of DHA, providing the possibility for the ternary complex formation. In summary, the ternary system prepared in our study, with simultaneous enhancement of DHA solubility and stability in aqueous solutions, might have an important pharmaceutical potential in the development of a better

Enhanced fluidity liquid chromatography of inulin fructans using ternary solvent strength and selectivity gradients.

Science.gov (United States)

Bennett, Raffeal; Olesik, Susan V

2018-01-25

The value of exploring selectivity and solvent strength ternary gradients in enhanced fluidity liquid chromatography (EFLC) is demonstrated for the separation of inulin-type fructans from chicory. Commercial binary pump systems for supercritical fluid chromatography only allow for the implementation of ternary solvent strength gradients which can be restrictive for the separation of polar polymeric analytes. In this work, a custom system was designed to extend the capability of EFLC to allow tuning of selectivity or solvent strength in ternary gradients. Gradient profiles were evaluated using the Berridge function (RF 1 ), normalized resolution product (NRP), and gradient peak capacity (P c ). Selectivity gradients provided the separation of more analytes over time. The RF 1 function showed favor to selectivity gradients with comparable P c to that of solvent strength gradients. NRP did not strongly correlate with P c or RF 1 score. EFLC with the hydrophilic interaction chromatography, HILIC, separation mode was successfully employed to separate up to 47 fructan analytes in less than 25 min using a selectivity gradient. Copyright © 2017 Elsevier B.V. All rights reserved.

Ternary particle yields in 249Cf(nth,f)

Science.gov (United States)

Tsekhanovich, I.; Büyükmumcu, Z.; Davi, M.; Denschlag, H. O.; Gönnenwein, F.; Boulyga, S. F.

2003-03-01

An experiment measuring ternary particle yields in 249Cf(nth,f) was carried out at the high flux reactor of the Institut Laue-Langevin using the Lohengrin recoil mass separator. Parameters of energy distributions were determined for 27 ternary particles up to 30Mg and their yields were calculated. The yields of 17 further ternary particles were estimated on the basis of the systematics developed. The heaviest particles observed in the experiment are 37Si and 37S; their possible origin is discussed.

The ternary system nickel-boron-silicon

International Nuclear Information System (INIS)

Lugscheider, E.; Reimann, H.; Knotek, O.

1975-01-01

The ternary system Nickel-Boron-Silicon was established at 850 0 C by means of X-ray diffraction, metallographic and micro-hardness examinations. The well known binary nickel borides and silicides resp. were confirmed. In the boron-silicon system two binary phases, SiBsub(4-x) with x approximately 0.7 and SiB 6 were found the latter in equilibrium with the β-rhombohedral boron. Confirming the two ternary silicon borides a greater homogeneity range was found for Ni 6 Si 2 B, the phase Nisub(4,6)Si 2 B published by Uraz and Rundqvist can better be described by the formula Nisub(4.29)Si 2 Bsub(1.43). In relation to further investigations we measured melting temperatures in ternary Ni-10 B-Si alloys by differential thermoanalysis. (author)

Design of ternary low-power Domino JKL flip—flop and its application

International Nuclear Information System (INIS)

Wang Pengjun; Yang Qiankun; Zheng Xuesong

2012-01-01

By researching the ternary flip—flop and the adiabatic Domino circuit, a novel design of low-power ternary Domino JKL flip—flop on the switch level is proposed. First, the switch-level structure of the ternary adiabatic Domino JKL flip—flop is derived according to the switch-signal theory and its truth table. Then the ternary loop operation circuit and ternary reverse loop operation circuit are achieved by employing the ternary JKL flip—flop. Finally, the circuit is simulated by using the Spice tool and the results show that the logic function is correct. The energy consumption of the ternary adiabatic Domino JKL flip—flop is 69% less than its conventional Domino counterpart. (semiconductor integrated circuits)

Phase equilibria in M-X-X' and M-Al-X ternary systems (M-transition metal, X,X'-B,C,N,Si) and crystal chemistry of ternary compounds

International Nuclear Information System (INIS)

Gusev, A.I.

1996-01-01

The data on phase equilibria in the M-X-X' and M-Al-X ternary systems (M-transition metal of 3 to 8 groups, X-B,C, N, Si) have been considered and summarized. modern oxygen-free advanced ceramics is based on these ternary systems. Phase diagrams of the 130 ternary systems have been discussed, more than two hundred ternary phases forming in these systems have been systematized and described. The typical crystal structures of ternary compounds and phase have been considered, the common and distinctive features of these structures have been analysed. It has been shown that the ternary compounds with octahedral atomic groups XM 6 have a regions of homogeneity. Refs. 240

Diagnostic accuracy of circulating thyrotropin receptor messenger RNA combined with neck ultrasonography in patients with Bethesda III-V thyroid cytology.

Science.gov (United States)

Aliyev, Altay; Patel, Jinesh; Brainard, Jennifer; Gupta, Manjula; Nasr, Christian; Hatipoglu, Betul; Siperstein, Allan; Berber, Eren

2016-01-01

The aim of this study was to analyze the usefulness of thyrotropin receptor messenger RNA (TSHR-mRNA) combined with neck ultrasonography (US) in the management of thyroid nodules with Bethesda III-V cytology. Cytology slides of patients with a preoperative fine needle aspiration (FNA) and TSHR-mRNA who underwent thyroidectomy between 2002 and 2011 were recategorized based on the Bethesda classification. Results of thyroid FNA, TSHR-mRNA, and US were compared with the final pathology. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. There were 12 patients with Bethesda III, 112 with Bethesda IV, and 58 with Bethesda V cytology. The sensitivity of TSHR-mRNA in predicting cancer was 33%, 65%, and 79 %, and specificity was 67%, 66%, and 71%, for Bethesda III, IV, and V categories, respectively. For the same categories, the PPV of TSHR-mRNA was 25%, 33%, and 79%, respectively; whereas the NPV was 75%, 88%, and 71%, respectively. The addition of neck US to TSHR-mRNA increased the NPV to 100% for Bethesda III, and 86%, for Bethesda IV, and 82% for Bethesda V disease. This study documents the potential usefulness of TSHR-mRNA for thyroid nodules with Bethesda III-V FNA categories. TSHR-mRNA may be used to exclude Bethesda IV disease. A large sample analysis is needed to determine its accuracy for Bethesda category III nodules. Copyright © 2016 Elsevier Inc. All rights reserved.

First principle study of UHTC ternary diboride, Cr2AlB2

Science.gov (United States)

Rastogi, Anugya; Rajpoot, Priyanka; Verma, U. P.

2018-04-01

In this paper ab-initio study of the structural, electronic and optical properties of ternary metal boride Cr2AlB2 using full potential linear augmented plane wave (FP-LAPW) method based on the density functional theory (DFT). The study of structural properties shows that Cr2AlB2 is metallic in nature and have orthorhombic crystal structure. The optical properties show that it possess anisotropic behavior, which have wide applications in electricity production through concentration of solar power (CSP) technology. To the best of our knowledge, theoretical study of the optical properties of Cr2AlB2 is reported for the first time.

Solvent Extraction and Separation of Chromium(III) and (V I) in Aqueous Solutions with Trioctylphosphine Oxide

International Nuclear Information System (INIS)

Sekine, T.; Yamada, M.

1999-01-01

The solvent extraction of chromium(III) and (V I) in aqueous solutions with a solvating type extractant, trioctylphosphine oxide(TOPO), in hexane is studied. Kinetically inert Cr 3+ is extracted from 1 mol dm -3 sodium perchlorate solution very quickly and quantitatively as Cr(H 2 O · TOPO) 6 3+ (CIO 4 -) 3 . Chromium(V I) in hydrochloric acid is extracted effectively as the H 2 CrO $ (H CI) n centre dot TOPO m species ( m = 2 or 3, n = 0 to 2) and the distribution ratio increased by an increase in the acid concentration. From these, a procedure is proposed for the extraction of both chromium(V I) and chromium(III) in aqueous solution separately with 0.1 mol dm -3 TOPO in hexane

Progress in III-V materials technology

Science.gov (United States)

Grant, Ian R.

2004-12-01

Compound semiconductors, in the form of GaAs and InP have achieved major commercial significance in areas of application such as mobile communications, displays and telecoms and offer a versatility of function beyond the capabilities of Si. III-V compounds, and in particular GaAs, have since their early development been the subject of defence related interest. Support from this sector established the basic materials technologies and nurtured development up until their commercial breakthrough into consumer products. GaAs, for example, now provides essential components for mobile phones and CD / DVD players. An overview is presented of the crystal growth and processing methods used in the manufacture of these materials. Current state of the art characteristics on crystal form and quality are discussed, together with the evolution of single crystal growth techniques. Consideration is given to how these principal compounds together with the minor materials, InSb, GaSb and InAs are employed in diverse applications over a broad spectral range, together with information on markets and future perspectives.

Role of ternary fission in synthesis of bypassed nuclei

International Nuclear Information System (INIS)

Kramarovskij, Ya.M.; Chechev, V.P.

1983-01-01

A possible influence of ternary fission with escape of neutron-enriched light charged particles on the synthesis of bypassed nuclides is considered. It is shown that this concept cannot give explanation of bypassed isotope concentrations, but it can make some contribution, if the probability of ternary fission for superheavy nuclei grows sharply with Z 2 /A parameter. The account of β-delayed fission contributes to the shift of ternary fission fragments into the region of neutron-deficient isotopes. Consistent consideration of the ternary fission role in the nucleosynthesis is possible only with an important accumulation of experimental and theoretical data on this process, particularly for the nuclei with Z > 100

Performance predictions for solar-chemical converters based on photoelectrochemical I-V curves

Energy Technology Data Exchange (ETDEWEB)

Luttmer, J.D.; Trachtenberg, I.

1985-06-01

Texas Instruments' solar energy system contains a solar-chemical converter (SCC) which converts solar energy into chemical energy via the electrolysis of hydrobromic acid (HBr) into hydrogen (H/sub 2/) and bromine (Br/sub 2/). Previous predictions of SCC performance have employed electrical dry-probe data and a computer simulation model to predict the H/sub 2/ generation rates. The method of prediction described here makes use of the photoelectrochemical Icurves to determine the ''wet'' probe parameters of V /SUB oc/ J /SUB sc/ FF, and efficiency for anodes and cathodes. The advantages of this technique over the dry-probe/computer simulation method are discussed. A comparison of predicted and measured H/sub 2/ generation rates is presented. Solar to chemical efficiencies of 8.6% have been both predicted and measured for the electrolysis of 48% HBr to hydrogen and bromine by a full anode/cathode array. Individual cathode solar to hydrogen efficiencies of 9.5% have been obtained.

Ternary particle yields in 249Cf(nth,f)

International Nuclear Information System (INIS)

Tsekhanovich, I.; Bueyuekmumcu, Z.; Davi, M.; Denschlag, H.O.; Goennenwein, F.; Boulyga, S.F.

2003-01-01

An experiment measuring ternary particle yields in 249 Cf(n th ,f) was carried out at the high flux reactor of the Institut Laue-Langevin using the Lohengrin recoil mass separator. Parameters of energy distributions were determined for 27 ternary particles up to 30 Mg and their yields were calculated. The yields of 17 further ternary particles were estimated on the basis of the systematics developed. The heaviest particles observed in the experiment are 37 Si and 37 S; their possible origin is discussed

Effects of Mg/Ga and V/III source ratios on hole concentration of N-polar (000\\bar{1}) p-type GaN grown by metalorganic vapor phase epitaxy

Science.gov (United States)

Nonoda, Ryohei; Shojiki, Kanako; Tanikawa, Tomoyuki; Kuboya, Shigeyuki; Katayama, Ryuji; Matsuoka, Takashi

2016-05-01

The effects of growth conditions such as Mg/Ga and V/III ratios on the properties of N-polar (000\\bar{1}) p-type GaN grown by metalorganic vapor phase epitaxy were studied. Photoluminescence spectra from Mg-doped GaN depended on Mg/Ga and V/III ratios. For the lightly doped samples, the band-to-acceptor emission was observed at 3.3 eV and its relative intensity decreased with increasing V/III ratio. For the heavily doped samples, the donor-acceptor pair emission was observed at 2.8 eV and its peak intensity monotonically decreased with V/III ratio. The hole concentration was maximum for the Mg/Ga ratio. This is the same tendency as in group-III polar (0001) growth. The V/III ratio also reduced the hole concentration. The higher V/III ratio reduced the concentration of residual donors such as oxygen by substituting nitrogen atoms. The surface became rougher with increasing V/III ratio and the hillock density increased.

New insights into thorium and uranium oxo-arsenic (III/V) and oxo-phosphates (V) crystal chemistry

Energy Technology Data Exchange (ETDEWEB)

Yu, Na

2015-12-11

The fundamental chemistry of actinides is of great interest owing to the diverse number of valence states and complex coordination chemistry of the actinides. The phases based on actinides and oxo-salt fragments have been under thorough investigation in the last decades. These compounds can be widely found in nature and they affect the migration process of actinides in nature. A better understanding of the fundamental coordination chemistry of actinide compounds with oxo-salts of group V elements is not only important for understanding the actinides behavior within the migration process but can also be used to understand actinide properties in phosphate ceramics. Concerning the radioactive issues, the less radioactive early actinides (i.e. U, Th) can be taken as modeling elements to study the crystal chemistry of the transuranic elements (Np, Pu) without the major handling problems. This can be done as Th(IV) has a very similar coordination chemistry with An(IV) and U(VI) can be chosen as a modeling element for transuranic elements in higher valence states. Therefore, a systematic research on the actinides (U, Th) bearing phases with tetrahedral oxo-anions such as phosphates and arsenates have been performed in this work. High temperature (HT) solid state reaction, High pressure high temperature (HP-HT) solid state reaction and the hydrothermal method were the methods of choice for synthesizing actinide bearing oxo-arsenic(III/V) and oxo- phosphorus(V) phases in the past three years. As a result, numerous novel compounds containing actinides were obtained. The structures of all compounds were determined using single crystal X-ray diffraction data. Raman spectroscopy, EDS, DSC and high temperature powder X-ray diffraction (HT-PXRD) measurements were implemented to characterize the chemical and physical properties of the obtained compounds. The core of this dissertation is a fundamental study of the crystal chemistry of actinides (Th, U) oxo-arsenic (III/V) and oxo-phosphate(V

Technetium cyanide chemistry: synthesis and characterization of technetium(III) and -(V) cyanide complexes

International Nuclear Information System (INIS)

Trop, H.S.; Jones, A.G.; Davison, A.

1980-01-01

Several new technetium cyanide complexes have been prepared and characterized. The reaction of ammonium hexaiodotechnetate(IV) with potassium cyanide in refluxing aqueous methanol under nitrogen yields potassium heptacyanotechnetate(III) dihydrate, K 4 Tc(CN) 7 .2H 2 O (1). Infrared and Raman measurements indicate that 1 has a pentagonal bipyramidal structure (D/sub 5h/) in both solid and solution. Aqueous solutions of 1 are air sensitive, decomposing to potassium oxopentacyanotechnetate(V) tetrahydrate, K 2 TcO(CN) 5 .4H 2 O (2). This species can also be prepared from the reaction of TcO 2 .xH 2 O with hot aqueous potassium cyanide solutions. Hydrolysis of 2 in water yields potassium trans-dioxo-tetracyanotechnetate(V), K 3 TcO 2 (CN) 4 (3). Preparation of 3 can also be achieved from the treatment of [TcO 2 (Py) 4 ]ClO 4 .2H 2 O with aqueous potassium cyanide. Infrared and Raman measurements on 3 are consistent with the proposed trans-dioxo (D/sub 4h/) structure. Reaction of the oxotetrachlorotechnetate(V) anion, TcOCl 4 , with potassium cyanide in methanol produces trans-oxomethoxytetracyanotechnetate(V). [TcO(OMe)(CN) 4 ] (4). The full details of the synthesis and characterization of these interesting technetium(III) and -(V) complexes, as well as observations on the infrared and Raman spectra of trans-dioxo metal complexes and the hydrolysis of species 2, are presented

The ternary post-transition metal carbodiimide SrZn(NCN){sub 2}

Energy Technology Data Exchange (ETDEWEB)

Corkett, Alex J.; Konze, Philipp M. [Institute of Inorganic Chemistry, RWTH Aachen University, Aachen (Germany); Dronskowski, Richard [Institute of Inorganic Chemistry, RWTH Aachen University, Aachen (Germany); Juelich-Aachen Research Alliance (JARA-HPC), RWTH-Aachen University, Aachen (Germany)

2017-11-17

SrZn(NCN){sub 2}, the first example of a ternary post-transition metal carbodiimide, was prepared by a solid-state metathesis reaction. The crystal structure was solved from PXRD data and found to adopt the orthorhombic (Cmcm) BaZnSO structure, a high symmetry modification of that expressed by the oxide analogue SrZnO{sub 2}. Locally, SrZn(NCN){sub 2} features ZnN{sub 4} tetrahedra and SrN{sub 6} trigonal prisms similar to those in quarternary LiSr{sub 2}M(NCN){sub 4} (M = Al{sup 3+} and Ga{sup 3+}) phases, however, the overall topologies are distinct with single chains in the former and double chains in the latter. Electronic structure calculations indicate an indirect bandgap of about 2.95 eV in SrZn(NCN){sub 2}, slightly lower than the experimentally observed bandgap of 3.4 eV in SrZnO{sub 2} and consistent with a greater degree of covalency. The structural similarities between SrZn(NCN){sub 2} and oxychalcogenide analogues highlight the pseudochalcogenide character of NCN{sup 2-} and suggest that the title compound may serve as a template for accessing novel ternary carbodiimides featuring tetrahedrally coordinated transition metals. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Quantum error-correcting code for ternary logic

Science.gov (United States)

Majumdar, Ritajit; Basu, Saikat; Ghosh, Shibashis; Sur-Kolay, Susmita

2018-05-01

Ternary quantum systems are being studied because they provide more computational state space per unit of information, known as qutrit. A qutrit has three basis states, thus a qubit may be considered as a special case of a qutrit where the coefficient of one of the basis states is zero. Hence both (2 ×2 ) -dimensional and (3 ×3 ) -dimensional Pauli errors can occur on qutrits. In this paper, we (i) explore the possible (2 ×2 ) -dimensional as well as (3 ×3 ) -dimensional Pauli errors in qutrits and show that any pairwise bit swap error can be expressed as a linear combination of shift errors and phase errors, (ii) propose a special type of error called a quantum superposition error and show its equivalence to arbitrary rotation, (iii) formulate a nine-qutrit code which can correct a single error in a qutrit, and (iv) provide its stabilizer and circuit realization.

Asymmetric supercapacitors with metal-like ternary selenides and porous graphene electrodes

KAUST Repository

Xia, Chuan

2016-04-14

Asymmetric supercapacitors provide a promising approach to fabricate capacitive energy storage devices with high energy and power densities. In this work, asymmetric supercapacitors with excellent performance have been fabricated using ternary (Ni, Co)0.85Se on carbon fabric as bind-free positive electrode and porous free-standing graphene films as negative electrode. Owing to their metal-like conductivity (~1.67×106 S m−1), significant electrochemical activity, and superhydrophilic nature, our nanostructured ternary nickel cobalt selenides result in a much higher areal capacitance (2.33 F cm−2 at 4 mA cm−2), better rate performance and cycling stability than their binary selenide equivalents, and other ternary oxides and chalcogenides. Those hybrid supercapacitors can afford impressive areal capacitance and stack capacitance of 529.3 mF cm−2 and 6330 mF cm−3 at 1 mA cm−2, respectively. More impressively, our optimized asymmetric device operating at 1.8 V delivers a very high stack energy density of 2.85 mWh cm−3 at a stack power density of 10.76 mW cm−3, as well as 85% capacitance retention after 10,000 continuous charge-discharge cycles. Even at a high stack power density of 1173 mW cm−3, this device still deliveries a stack energy density of 1.19 mWh cm−3, superior to most of the reported supercapacitors.

III/V nano ridge structures for optical applications on patterned 300 mm silicon substrate

Energy Technology Data Exchange (ETDEWEB)

Kunert, B.; Guo, W.; Mols, Y.; Pantouvaki, M.; Van Campenhout, J.; Langer, R.; Barla, K. [imec, Kapeldreef 75, 3001 Heverlee (Belgium); Tian, B.; Wang, Z.; Shi, Y.; Van Thourhout, D. [Photonics Research Group, Ghent University, Technologiepark-Zwijnaarde 15, 9052 Gent (Belgium)

2016-08-29

We report on an integration approach of III/V nano ridges on patterned silicon (Si) wafers by metal organic vapor phase epitaxy (MOVPE). Trenches of different widths (≤500 nm) were processed in a silicon oxide (SiO{sub 2}) layer on top of a 300 mm (001) Si substrate. The MOVPE growth conditions were chosen in a way to guarantee an efficient defect trapping within narrow trenches and to form a box shaped ridge with increased III/V volume when growing out of the trench. Compressively strained InGaAs/GaAs multi-quantum wells with 19% indium were deposited on top of the fully relaxed GaAs ridges as an active material for optical applications. Transmission electron microcopy investigation shows that very flat quantum well (QW) interfaces were realized. A clear defect trapping inside the trenches is observed whereas the ridge material is free of threading dislocations with only a very low density of planar defects. Pronounced QW photoluminescence (PL) is detected from different ridge sizes at room temperature. The potential of these III/V nano ridges for laser integration on Si substrates is emphasized by the achieved ridge volume which could enable wave guidance and by the high crystal quality in line with the distinct PL.

Fusibility diagram of ternary system with incongruently melting double compound

International Nuclear Information System (INIS)

Lutsyk, V.I.; Vorob'eva, V.P.; Sumkina, O.G.

1989-01-01

Temperature calculation and properties of ternary eutectics and concentration coordinates of ternary peritectics accoriding to the linear model of initial crystallization surfaces as an element of the expert system for simulating fusibility diagrams of ternary systems is considered. It is shown that the calculated and experimental data on coordinates of ternary nonvariant points in the systems NaCl-PbCl 2 -CdCl 2 , PbCl 2 -CaCl 2 -UCl 4 , CaF 2 -NaF-CsF and UCl 3 -CaCl 2 -ThCl 4 are in good agreement

Crystallization features of ternary reversible reciprocal systems

International Nuclear Information System (INIS)

Tomashik, V.N.; Shcherbak, L.P.; Fejchuk, P.I.; Grytsiv, V.I.

2006-01-01

Some features of the primary crystallization of phases in ternary reversible reciprocal system are considered and discussed. The diagonal join CdTe-GeSe of the CdTe + GeSe = CdSe + GeTe ternary reciprocal system is studied to show that the features in primary and secondary heating and cooling curves in such systems under fully equilibrium conditions are not reproduced upon consecutive heating and cooling sessions, because of the existence of different amounts of the reagents and the reaction products in the mixture; the temperatures of each transformation lie in a range. Those who experimentally investigate other ternary and more complex reversible reciprocal systems should take this fact into account [ru

As(III) oxidation by active chlorine and subsequent removal of As(V) by Al13 polymer coagulation using a novel dual function reagent.

Science.gov (United States)

Hu, Chengzhi; Liu, Huijuan; Chen, Guixia; Jefferson, William A; Qu, Jiuhui

2012-06-19

An electrochemically prepared water treatment reagent containing a high concentration of Al(13) polymer and active chlorine (PACC) showed promising potential for the removal of As(III) due to the combined function of oxidation and coagulation. The results indicated that PACC was effective for As(III) removal through oxidation by the active chlorine and subsequent removal of As(V) by coagulation with the Al(13) polymer. The As(III) was oxidized to As(V) by active chlorine in PACC, with a stoichiometric rate of 0.99 mg Cl(2)/mg As(III). The Al(13) polymer was the most active Al species responsible for As(V) removal in PACC. To meet As drinking water standards the stoichiometric weight ratio of Cl(2)/Al within PACC was 0.09 for the treatment of As(III). Considering the process of As(III) oxidation and As(V) coagulation together, the optimal pH conditions for the removal of As by PACC was within the neutral range, which facilitated the reaction of As(III) with active chlorine and favored the formation of Al hydroxide flocs. The presence of humic acid reduced the As(III) removal efficiency of PACC due to its negative influence on subsequent As(V) coagulation, and disinfection byproduct yields were very low in the presence of insufficient or stoichiometric active chlorine.

Thermodynamic model for solution behavior and solid-liquid equilibrium in Na-Al(III)-Fe(III)-Cr(III)-Cl-H2O system at 25°C

Science.gov (United States)

André, Laurent; Christov, Christomir; Lassin, Arnault; Azaroual, Mohamed

2018-03-01

The knowledge of the thermodynamic behavior of multicomponent aqueous electrolyte systems is of main interest in geo-, and environmental-sciences. The main objective of this study is the development of a high accuracy thermodynamic model for solution behavior, and highly soluble M(III)Cl3(s) (M= Al, Fe, Cr) minerals solubility in Na-Al(III)-Cr(III)-Fe(III)-Cl-H2O system at 25°C. Comprehensive thermodynamic models that accurately predict aluminium, chromium and iron aqueous chemistry and M(III) mineral solubilities as a function of pH, solution composition and concentration are critical for understanding many important geochemical and environmental processes involving these metals (e.g., mineral dissolution/alteration, rock formation, changes in rock permeability and fluid flow, soil formation, mass transport, toxic M(III) remediation). Such a model would also have many industrial applications (e.g., aluminium, chromium and iron production, and their corrosion, solve scaling problems in geothermal energy and oil production). Comparisons of solubility and activity calculations with the experimental data in binary and ternary systems indicate that model predictions are within the uncertainty of the data. Limitations of the model due to data insufficiencies are discussed. The solubility modeling approach, implemented to the Pitzer specific interaction equations is employed. The resulting parameterization was developed for the geochemical Pitzer formalism based PHREEQC database.

Recombination in polymer:Fullerene solar cells with open-circuit voltages approaching and exceeding 1.0 V

KAUST Repository

Hoke, Eric T.

2012-09-14

Polymer:fullerene solar cells are demonstrated with power conversion efficiencies over 7% with blends of PBDTTPD and PC 61 BM. These devices achieve open-circuit voltages ( V oc ) of 0.945 V and internal quantum efficiencies of 88%, making them an ideal candidate for the large bandgap junction in tandem solar cells. V oc \\'s above 1.0 V are obtained when the polymer is blended with multiadduct fullerenes; however, the photocurrent and fill factor are greatly reduced. In PBDTTPD blends with multiadduct fullerene ICBA, fullerene emission is observed in the photoluminescence and electroluminescence spectra, indicating that excitons are recombining on ICBA. Voltage-dependent, steady state and time-resolved photoluminescence measurements indicate that energy transfer occurs from PBDTTPD to ICBA and that back hole transfer from ICBA to PBDTTPD is inefficient. By analyzing the absorption and emission spectra from fullerene and charge transfer excitons, we estimate a driving free energy of -0.14 ± 0.06 eV is required for efficient hole transfer. These results suggest that the driving force for hole transfer may be too small for efficient current generation in polymer:fullerene solar cells with V oc values above 1.0 V and that non-fullerene acceptor materials with large optical gaps ( > 1.7 eV) may be required to achieve both near unity internal quantum efficiencies and values of V oc exceeding 1.0 V. © 2013 WILEY-VCH Verlag GmbH and Co.

Recombination in polymer:Fullerene solar cells with open-circuit voltages approaching and exceeding 1.0 V

KAUST Repository

Hoke, Eric T.; Vandewal, Koen; Bartelt, Jonathan A.; Mateker, William R.; Douglas, Jessica D.; Noriega, Rodrigo; Graham, Kenneth; Frechet, Jean; Salleo, Alberto; McGehee, Michael D.

2012-01-01

Polymer:fullerene solar cells are demonstrated with power conversion efficiencies over 7% with blends of PBDTTPD and PC 61 BM. These devices achieve open-circuit voltages ( V oc ) of 0.945 V and internal quantum efficiencies of 88%, making them an ideal candidate for the large bandgap junction in tandem solar cells. V oc 's above 1.0 V are obtained when the polymer is blended with multiadduct fullerenes; however, the photocurrent and fill factor are greatly reduced. In PBDTTPD blends with multiadduct fullerene ICBA, fullerene emission is observed in the photoluminescence and electroluminescence spectra, indicating that excitons are recombining on ICBA. Voltage-dependent, steady state and time-resolved photoluminescence measurements indicate that energy transfer occurs from PBDTTPD to ICBA and that back hole transfer from ICBA to PBDTTPD is inefficient. By analyzing the absorption and emission spectra from fullerene and charge transfer excitons, we estimate a driving free energy of -0.14 ± 0.06 eV is required for efficient hole transfer. These results suggest that the driving force for hole transfer may be too small for efficient current generation in polymer:fullerene solar cells with V oc values above 1.0 V and that non-fullerene acceptor materials with large optical gaps ( > 1.7 eV) may be required to achieve both near unity internal quantum efficiencies and values of V oc exceeding 1.0 V. © 2013 WILEY-VCH Verlag GmbH and Co.

The Effect of Growth Temperature and V/III Flux Ratio of MOCVD Antimony Based Semiconductors on Growth Rate and Surface Morphology

Directory of Open Access Journals (Sweden)

Ramelan Ari Handono

2017-01-01

Full Text Available Epitaxial Alx Ga1-x Sb layers on GaSb and GaAs substrates have been grown by atmospheric pressure metalorganic chemical vapor deposition using TMAl, TMGa and TMSb. Nomarski microscope and a profiler were employed to examine the surface morphology and growth rate of the samples. We report the effect of growth temperature and V/III flux ratio on growth rate and surface morphology. Growth temperatures in the range of 520°C and 680°C and V/III ratios from 1 to 5 have been investigated. A growth rate activation energy of 0.73 eV was found. At low growth temperatures between 520 and 540°C, the surface morphology is poor due to antimonide precipitates associated with incomplete decomposition of the TMSb. For layers grown on GaAs at 580°C and 600°C with a V/III ratio of 3 a high quality surface morphology is typical, with a mirror-like surface and good composition control. It was found that a suitable growth temperature and V/III flux ratio was beneficial for producing good AlGaSb layers. Undoped AlGaSb grown at 580°C with a V/III flux ratio of 3 at the rate of 3.5 μm/hour shows p-type conductivity with smooth surface morphology

Influence of V/III growth flux ratio on trap states in m-plane GaN grown by ammonia-based molecular beam epitaxy

International Nuclear Information System (INIS)

Zhang, Z.; Arehart, A. R.; Hurni, C. A.; Speck, J. S.; Ringel, S. A.

2012-01-01

Deep level transient spectroscopy (DLTS) and deep level optical spectroscopy (DLOS) were utilized to investigate the behavior of deep states in m-plane, n-type GaN grown by ammonia-based molecular beam epitaxy (NH 3 -MBE) as a function of systematically varied V/III growth flux ratios. Levels were detected at E C - 0.14 eV, E C - 0.21 eV, E C - 0.26 eV, E C - 0.62 eV, E C - 0.67 eV, E C - 2.65 eV, and E C - 3.31 eV, with the concentrations of several traps exhibiting systematic dependencies on V/III ratio. The DLTS spectra are dominated by traps at E C - 0.14 eV and E C - 0.67 eV, whose concentrations decreased monotonically with increasing V/III ratio and decreasing oxygen impurity concentration, and by a trap at E C - 0.21 eV that revealed no dependence of its concentration on growth conditions, suggestive of different physical origins. Higher concentrations of deeper trap states detected by DLOS with activation energies of E C - 2.65 eV and E C - 3.31 eV in each sample did not display measureable sensitivity to the intentionally varied V/III ratio, necessitating further study on reducing these deep traps through growth optimization for maximizing material quality of NH 3 -MBE grown m-plane GaN.

Electrochemical studies on electroless ternary and quaternary Ni-P based alloys