WorldWideScience

Sample records for cd-free cigs based

  1. Fabrication of high-quality ZnS buffer and its application in Cd-free CIGS solar cells

    Science.gov (United States)

    Li, Feng-yan; Dang, Xiang-yu; Zhang, Li; Liu, Fang-fang; Sun, Ding; He, Qing; Li, Chang-jian; Li, Bao-zhang; Zhu, Hong-bing

    2014-07-01

    This paper provides the fabrication of Cd-free Cu(In,Ga)Se2 (CIGS) solar cells on soda-lime glass substrates. A high quality ZnS buffer layer is grown by chemical bath deposition (CBD) process with ZnSO4-NH3-SC (NH2)2 aqueous solution system. The X-ray diffraction (XRD) result shows that the as-deposited ZnS film has cubic (111) and (220) diffraction peaks. Scanning electron microscope (SEM) images indicate that the ZnS film has a dense and compact surface with good crystalline quality. Transmission measurement shows that the optical transmittance is about 90% when the wavelength is beyond 500 nm. The bandgap ( E g ) value of the as-deposited ZnS film is estimated to be 3.54 eV. Finally, a competitive efficiency of 11.06% is demonstrated for the Cd-free CIGS solar cells with ZnS buffer layer after light soaking.

  2. Cd-free heterojunctions in chalcopyrite based thin film solar cells; Cd-freie Heterokontakte in Chalkopyrit-basierten Duennschichtsolarzellen

    Energy Technology Data Exchange (ETDEWEB)

    Kieven, David

    2012-02-06

    This thesis took care of the problem to replace the buffer layers Cds and i-ZnO in thin-film solar cells of the layer system p-Cu(In,Ga)(Se,S){sub 2}/CdS/i-ZnO/n{sup +} by a Cd-free buffer layer. The synthesis of the material layers. The synthesis was carried out by the method of cathode sputtering established in the deposition of the n{sup +}-ZnO window layer. Aim was to modify the electronic properties of the studied materials either by the choice of the applied bonding elements or by the choice of the composition in such a way that the basic conditions for buffer layers are fulfilled: Optical transparency and suited band fitting to the absorber material. The analysis of the interfaces between the potential buffer materials and the Cu(In,Ga)(Se,S){sub 2} absorber material considering the conduction-band fitting important for solar cells formed a main topic. Finally suited materials came into application as buffer layers in Cu(In,Ga)(Se,S){sub 2}-based thin-film solar cells. Thereby was of interest, whether efficient solar cells can be fabricated, and whether the photovoltaic parameters open-circuit voltage and short-circuit current density are dominantly influenced by possible interface defects, as they are especially discussed in connection with the sputtering deposition.

  3. All-Nonvacuum-Processed CIGS Solar Cells Using Scalable Ag NWs/AZO-Based Transparent Electrodes.

    Science.gov (United States)

    Wang, Mingqing; Choy, Kwang-Leong

    2016-07-06

    With record cell efficiency of 21.7%, CIGS solar cells have demonstrated to be a very promising photovoltaic (PV) technology. However, their market penetration has been limited due to the inherent high cost of the cells. In this work, to lower the cost of CIGS solar cells, all nonvacuum-processed CIGS solar cells were designed and developed. CIGS absorber was prepared by the annealing of electrodeposited metallic layers in a chalcogen atmosphere. Nonvacuum-deposited Ag nanowires (NWs)/AZO transparent electrodes (TEs) with good transmittance (92.0% at 550 nm) and high conductivity (sheet resistance of 20 Ω/□) were used to replace the vacuum-sputtered window layer. Additional thermal treatment after device preparation was conducted at 220 °C for a few of minutes to improve both the value and the uniformity of the efficiency of CIGS pixel cell on 5 × 5 cm substrate. The best performance of the all-nonvacuum-fabricated CIGS solar cells showed an efficiency of 14.05% with Jsc of 34.82 mA/cm(2), Voc of 0.58 V, and FF of 69.60%, respectively, which is comparable with the efficiency of 14.45% of a reference cell using a sputtered window layer.

  4. Photovoltaic manufacturing cost and throughput improvements for thin-film CIGS-based modules: Phase 1 technical report, July 1998--July 1999

    Energy Technology Data Exchange (ETDEWEB)

    Wiedeman, S.; Wendt, R.G.

    2000-03-01

    The primary objectives of the Global Solar Energy (GSE) Photovoltaic Manufacturing Technology (PVMaT) subcontract are directed toward reducing cost and expanding the production rate of thin-film CuInGaSe{sub 2} (CIGS)-based PV modules on flexible substrates. Improvements will be implemented in monolithic integration, CIGS deposition, contact deposition, and in-situ CIGS control and monitoring. In Phase 1, GSE has successfully attacked many of the highest risk aspects of each task. All-laser, selective scribing processes for CIGS have been developed, and many end-of-contract goals for scribing speed have been exceeded in the first year. High-speed ink-jet deposition of insulating material in the scribes now appears to be a viable technique, again exceeding some end-of-contract goals in the first year. Absorber deposition of CIGS was reduced corresponding to throughput speeds of up to 24-in/min, also exceeding an end-of-contract goal. Alternate back-contact materials have been identified that show potential as candidates for replacement of higher-cost molybdenum, and a novel, real-time monitoring technique (parallel-detector spectroscopic ellipsometry) has shown remarkable sensitivity to relevant properties of the CIGS absorber layer for use as a diagnostic tool. Currently, one of the bilayers has been baselined by GSE for flexible CIGS on polymeric substrates. Resultant back-contacts meet sheet-resistance goals and exhibit much less intrinsic stress than Mo. CIGS has been deposited, and resultant devices are comparable in performance to pure Mo back-contacts. Debris in the chamber has been substantially reduced, allowing longer roll-length between system cleaning.

  5. Trajectory-Oriented and Fault-Tolerant-Based Intelligent Process Control for Flexible CIGS PV Module Manufacturing; Final Technical Report, 13 May 2002--30 May 2005

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, L.; Britt, J.; Birkmire, R.; Vincent, T.

    2005-10-01

    ITN Energy Systems, Inc., and Global Solar Energy, Inc., assisted by NREL's PV Manufacturing R&D program, have continued to advance CIGS production technology by developing trajectory-oriented predictive/control models, fault-tolerance control, control platform development, in-situ sensors, and process improvements. Modeling activities included developing physics-based and empirical models for CIGS and sputter-deposition processing, implementing model-based control, and applying predictive models to the construction of new evaporation sources and for control. Model-based control is enabled by implementing reduced or empirical models into a control platform. Reliability improvement activities include implementing preventive maintenance schedules; detecting failed sensors/equipment and reconfiguring to tinue processing; and systematic development of fault prevention and reconfiguration strategies for the full range of CIGS PV production deposition processes. In-situ sensor development activities have resulted in improved control and indicated the potential for enhanced process status monitoring and control of the deposition processes. Substantial process improvements have been made, including significant improvement in CIGS uniformity, thickness control, efficiency, yield, and throughput. In large measure, these gains have been driven by process optimization, which in turn have been enabled by control and reliability improvements due to this PV Manufacturing R&D program.

  6. Analysis on the Performance of Copper Indium Gallium Selenide (CIGS Based Photovoltaic Thermal

    Directory of Open Access Journals (Sweden)

    Zulkepli Afzam

    2016-01-01

    Full Text Available This paper deals with the efficiency improvement of Copper Indium Gallium Selenide (CIGS Photovoltaic (PV and also solar thermal collector. Photovoltaic thermal (PV/T can improve overall efficiency for PV and also solve the problem of limited roof space at urban area. Objective of this study is to clarify the effect of mass flow rate on the efficiency of the PV/T system. A CIGS solar cell is used with rated output power 65 W and 1.18 m2 of area. 4 set of experiments were carried out, which were: thermal collector with 0.12 kg/s flow rate, PV/T with 0.12 kg/s flow rate, PV/T with 0.09 kg/s flow rate and PV. It was found that PV/T with 0.12 kg/s flow rate had the highest electrical efficiency, 2.92 %. PV/T with 0.09 kg/s flow rate had the lowest electrical efficiency, 2.68 %. It also had 2 % higher overall efficiency. The efficiency gained is low due to several factors. The rated output power of the PV is low for the area of 1.18 m2. The packing factor of the PV also need to be considered as it may not be operated at the optimal packing factor. Furthermore, aluminium sheet of the PV may affect the PV temperature due to high thermal conductivity. Further study on more values of mass flow rate and also other parameters that affect the efficiency of the PV/T is necessary.

  7. Structure and properties of CIGS films based on one-stage RF-sputtering process at low substrate temperature

    Institute of Scientific and Technical Information of China (English)

    Yong Yan; Shasha Li; Yufeng Ou; Yaxin Ji; Chuanpeng Yan; Lian Liu; Zhou Yu; Yong Zhao

    2014-01-01

    Currently, Nanjing South Railway Station planning to implement slate roof renovation is integrating solar cell modules into traditional roof materials to gen-erate clean energy. Copper-indium-gallium diselenide (CuIn1-xGaxSe2, CIGS) is one of the most promising materials for thin film solar cells. Cu(In1-xGax)Se2 films were deposited by a one-step radio frequency magnetron sputtering process at low substrate temperature. X-ray diffraction, Raman, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and electrical and optical measurements were carried out to investigate the deposited films. The results reveal that a temperature of 320 ?C is critical for near-stoichiometric CIGS films with uniform surface morphology. Cu-rich phase particulates are found at less than this temperature. The sample deposited at 380 ?C gives well-crystalline single-phase CIGS film. Furthermore, the electrical and optical performances of the absorber layer are improved significantly with the increasing substrate temperature.

  8. ETUDE ET SIMULATION DE CELLULES PHOTOVOLTAIQUES A COUCHES MINCES A BASE DE CIS et CIGS

    OpenAIRE

    MOSTEFA KARA, Selma

    2012-01-01

    Dans le contexte global de la diversification de l’utilisation des ressources naturelles, le recours aux énergies renouvelables et en particulier le solaire photovoltaïque se fait de plus en plus fort. A ce titre, le développement d’une nouvelle génération de cellules photovoltaïques à base de Cu(In,Ga)Se2 semble prometteur. En effet, le rendement de ces cellules a dépassé les 20% ces dernières années. Dans ce travail de modélisation et de simulation, nous utilisons le logiciel Si...

  9. Process Development for CIGS-Based Thin-Film Photovoltaic Modules; Phase I Technical Report, 5 February 1998--4 February 1999

    Energy Technology Data Exchange (ETDEWEB)

    Britt, J., Wiedeman, S.; Wendt, R.; Albright, S.

    1999-09-13

    This report describes work performed by Global Solar Energy (GSE) under Phase I of this subcontract. GSE has initiated an extensive and systematic plan to accelerate the commercialization of thin-film photovoltaics (PV) on copper indium gallium diselenide (CIGS). GSE is developing the technology to deposit and monolithically integrate CIGS photovoltaics on a flexible substrate. CIGS-deposited on flexible substrates can be fabricated into either flexible or rigid modules. Low-cost, rigid PV panels for remote power, bulk/utility, telecommunications, and rooftop applications will be produced by affixing the flexible CIGS to an expensive rigid panel by lamination or adhesive. In the GSE approach, long (up to 700 m) continuous rolls of substrate are processed, as opposed to individual small glass plates. In combination with roll-to-roll processing, GSE is developing evaporation deposition operations that enable low-cost and high-efficiency CIGS modules. Efforts are under way to transition the CIGS deposition process into manufacturing at GSE. CIGS process development is focused on synchronizing the operation of the effusion sources, the Se delivery profile, substrate temperature, and a host of other parameters. GSE has selected an interconnect scheme and procured, installed, and tested the equipment necessary to implement the cell interconnection for thin-film CIGS modules on a polyimide substrate.

  10. Physics-Based Compact Model for CIGS and CdTe Solar Cells: From Voltage-Dependent Carrier Collection to Light-Enhanced Reverse Breakdown: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Xingshu; Alam, Muhammad Ashraful; Raguse, John; Garris, Rebekah; Deline, Chris; Silverman, Timothy

    2015-10-15

    In this paper, we develop a physics-based compact model for copper indium gallium diselenide (CIGS) and cadmium telluride (CdTe) heterojunction solar cells that attributes the failure of superposition to voltage-dependent carrier collection in the absorber layer, and interprets light-enhanced reverse breakdown as a consequence of tunneling-assisted Poole-Frenkel conduction. The temperature dependence of the model is validated against both simulation and experimental data for the entire range of bias conditions. The model can be used to characterize device parameters, optimize new designs, and most importantly, predict performance and reliability of solar panels including the effects of self-heating and reverse breakdown due to partial-shading degradation.

  11. Commercialization of High Efficiency Low Cost CIGS Technology Based on Electroplating: Final Technical Progress Report, 28 September 2007 - 30 June 2009

    Energy Technology Data Exchange (ETDEWEB)

    Basol, B.

    2010-08-01

    This report describes SoloPower's work as a Photovoltaic Technology Incubator awardee within the U.S. Department of Energy's Solar Energy Technologies Program. The term of this subcontract with the National Renewable Energy Laboratory was two years. The project focused on SoloPower's electrodeposition-based copper indium gallium (di)selenide (CIGS) technology. Under this subcontract, SoloPower improved the quality of its flexible metal substrates, increased the size of its solar cells from 0.5 cm2 to 120 cm2, increased the small-area cell efficiencies from near 11% to near 14%, demonstrated large-area cells, and developed a module manufacturing process.

  12. Cost and Reliability Improvement for CIGS-Based PV on Flexible Substrate: May 24, 2006 -- July 31, 2010

    Energy Technology Data Exchange (ETDEWEB)

    Wiedeman, S.

    2011-05-01

    Global Solar Energy rapidly advances the cost and performance of commercial thin-film CIGS products using roll-to-roll processing on steel foil substrate in compact, low cost deposition equipment, with in-situ sensors for real-time intelligent process control. Substantial increases in power module efficiency, which now exceed 13%, are evident at GSE factories in two countries with a combined capacity greater than 75 MW. During 2009 the average efficiency of cell strings (3780 cm2) was increased from 7% to over 11%, with champion results exceeding 13% Continued testing of module reliability in rigid product has reaffirmed extended life expectancy for standard glass product, and has qualified additional lower-cost methods and materials. Expected lifetime for PV in flexible packages continues to increase as failure mechanisms are elucidated, and resolved by better methods and materials. Cost reduction has been achieved through better materials utilization, enhanced vendor and material qualification and selection. The largest cost gains have come as a result of higher cell conversion efficiency and yields, higher processing rates, greater automation and improved control in all process steps. These improvements are integral to this thin film PV partnership program, and all realized with the 'Gen2' manufacturing plants, processes and equipment.

  13. Revised positions for the CIG galaxies

    CERN Document Server

    Leon, S

    2003-01-01

    We present revised positions for the 1051 galaxies belonging to the Karachentseva Catalog of Isolated Galaxies (CIG). New positions were calculated by applying SExtractor to the Digitized Sky Survey CIG fields with a spatial resolution of 1.2''. We visually checked the results and for 118 galaxies had to recompute the assigned positions due to complex morphologies (e.g. distorted isophotes, undefined nuclei, knotty galaxies) or the presence of bright stars. We found differences between older and newer positions of up to 38'' with a mean value of 2.96'' relative to SIMBAD and up to 38'' and 2.42'' respectively relative to UZC. Based on star positions from the APM catalog we determined that the DSS astrometry of five CIG fields has a mean offset in (RA, Dec) of (-0.90'',0.93'') with a dispersion of 0.4''. These results have been confirmed using the 2MASS All-Sky Catalog of Point Sources. The intrinsic errors of our method combined with the astrometric ones are of the order of 0.5''.

  14. Degradation of CIGS solar cells

    NARCIS (Netherlands)

    Theelen, M.J.

    2015-01-01

    Thin film CIGS solar cells and individual layers within these solar cells have been tested in order to assess their long term stability. Alongside with the execution of standard tests, in which elevated temperatures and humidity levels are used, the solar cells have also been exposed to a combinatio

  15. DLTS Characterization of CIGS Cells

    Energy Technology Data Exchange (ETDEWEB)

    Kerr, L. L.; Li, S. S.; Anderson, T. J.; Crisalle, O. D.; Johnston, S.; Abushama, J.; Noufi, R.

    2003-06-01

    Deep Level Transient Spectroscopy (DLTS) and Capacitance-Voltage (C-V) measurements are employed to study deep-level electron and hole traps in CIGS solar cells fabricated at two different locations (EPV and NREL). The activation energy and trap density as well as suggested defect origins are given.

  16. A study on the optics of copper indium gallium (di)selenide (CIGS) solar cells with ultra-thin absorber layers

    NARCIS (Netherlands)

    Xu, M.; Wachters, A.J.H.; Van Deelen, J.; Mourad, M.C.D.; Buskens, P.J.P.

    2014-01-01

    We present a systematic study of the effect of variation of the zinc oxide (ZnO) and copper indium gallium (di)selenide (CIGS) layer thickness on the absorption characteristics of CIGS solar cells using a simulation program based on finite element method (FEM). We show that the absorption in the CIG

  17. CIGS Thin Film Solar Cells, phase 2 Uppsala University Final report 2006-01-01 - 2007-06-14

    Energy Technology Data Exchange (ETDEWEB)

    Edoff, Marika (Thin Film Solar Cell group, Dep. Technical Sciences, Uppsala Univ., P.O. Box 534, SE-751 21 Uppsala (Sweden)) (and others)

    2007-06-15

    The project CIGS Thin Film Solar Cells, phase 2 has been going on for 18,5 months and was interrupted in advance on the 14th of June, 2007. The decision to shorten the period was taken by the board of the Swedish Energy Agency the 14th of February. It was decided to reevaluate and re-direct the financial support to the group. A new project, CIGS Thin Film Solar Cells, phase 3, superseded this project and will go on for the initially planned project period (until 2009-12-31). During the project much of the focus has been on research on Cd-free buffer layers, with an emphasis on the interface properties between the CIGS and the buffer layer. (CIGS is a commonly used acronym for Cu(In,Ga)Se{sub 2}, which is the active absorption layer in this type of solar cells) The combination of high quality CIGS and the new buffer layers has been another field of interest. CIGS solar cell module development and computer modelling of solar cells and modules has been the third major research area. The results show that the group still holds a position as one of the leaders in the world in this field. The 18.5 % efficient Cd-free solar cell, which was obtained and independently confirmed is only one percent away from the world record and in addition it is Cd-free using a Zn(O,S) buffer layer (the world record from NREL contains Cd). By alloying ZnO with MgO instead of ZnS almost equally good results can be achieved. During the last half year an 18.1 % cell has been measured with a (Zn,Mg)O buffer layer. Solar cell module technology includes several research issues, both fundamental as e.g. modelling of cell voltage and losses as a function of distance from interconnect to interconnect, but also more development as e.g. encapsulation routines. The harsh environment test (damp heat test) run at 85 deg C and 85 % relative humidity for 1000 hours was passed for both a small (12.5x12.5 cm2) and a large (27.5x30 cm2) module within the degradation limits stated by the IEC standards, using

  18. Thin-Film CIGS Photovoltaic Technology: Annual Technical Report-Phase II, 16 April 1999-15 April 2000

    Energy Technology Data Exchange (ETDEWEB)

    Delahoy, A.E.; Bruns, J.; Ruppert, A.; Akhtar, M.; Chen, L.; Kiss, Z.J.

    2000-08-24

    A summary of Energy Photovoltaics' Phase II work includes the following: (1) EPV has demonstrated that it can sputter a Mo back-contact capable of supporting very high efficiency cell processing. Using EPV Mo, NREL has deposited a 17.1% CIGS cell (no AR coating). EPV believes it can identify the signature of ``good'' Mo. The Mo was produced on EPV's 0.43 m{sup 2} pilot-line equipment; (2) EPV has performed compound synthesis for several classes of materials, namely non-Cu precursor materials, Cu-containing materials, and ternary buffer materials. Using a ternary compound synthesized at EPV (ZIS) as an evaporation source material for the buffer layer, a Cd-free CIGS device has been produced having an efficiency of 11.5% (560 mV, 32.1 mA/cm{sup 2}, FF 64.3%). The ZIS films are photoconductive, and the devices exhibit no dark-light crossover or light soaking effects; (3) EPV initiated the interest of the University of Oregon in capacitance spectroscopy of CIGS devices. An Urbach tail with characteristic energy E0 < 20meV was identified by transient photocapacitance spectroscopy; (4) Small-area CIGS devices were produced in the pilot-line system with an efficiency of 12.0% (581 mV, 30.1 mA/cm{sup 2}, FF 68.7%), and in an R and D-scale system with 13.3% efficiency (569 mV, 34.1 mA/cm{sup 2}, FF 68.1%); (5) An improved linear evaporation source for Cu delivery has been developed and was used for CIGS formation in the pilot-line system. The deposition width is 45 cm. This technological ``tour de force'' allows EPV to build large-area CIGS systems possessing considerable flexibility. In particular, both EPV's FORNAX process and NREL's 3-stage process have been implemented on the pilot line. A CIGS thickness uniformity of 7% over a 40 cm width has been achieved; (6) A 4-head linear source assembly was designed, constructed, and is in use. Flux monitoring is practiced; (7) Large-area CIGS modules were produced with Voc's up to 36

  19. Alternative bufferlayers for CIGS solarcells

    Energy Technology Data Exchange (ETDEWEB)

    Beleanu, A.; Gruhn, T.; Blum, C.G.F.; Balke, B.; Felser, C. [Institute of Inorganic and Analytical Chemistry, Johannes Gutenberg - University, Mainz (Germany)

    2010-07-01

    Cadmium sulfide is a highly efficient buffer layer material in Cu(In,Ga)(S,Se2)[CIGS] solar devices, but for environmental reasons and possible gains in efficiency there is a great interest in replacing CdS by a cadmium-free alternative buffer layer. Using standard density functional theory (DFT) methods possible candidates like LiZnP and LiCuS have been proposed as alternative buffer layers. The experimental verification of the DFT results was quite challenging due to the fact that LiCuS was an unknow and completely new material. In a first step, we tried to synthesize LiCuS through solid state reactions in a corund crucible. After optimizing the parameters and successfully synthesizing the material its properties were investigated. In a second step, huge amounts of LiCuS and LiZnP were synthesized and pressed using Spark Plasma Sintering as 3 inch targets. LiCuS and LiZnP films were grown by radio-frequency magnetron sputtering from these target and their properties as an alternative buffer layer in CIGS solar cells were investigated. The 1:1:1 stoichiometry of the films was delivered from in-situ XPS measurements. Absorption measurements show a band gap of {approx}2.0 eV which is in good agreement with the theoretical estimates.

  20. Computational Infrastructure for Geodynamics (CIG)

    Science.gov (United States)

    Gurnis, M.; Kellogg, L. H.; Bloxham, J.; Hager, B. H.; Spiegelman, M.; Willett, S.; Wysession, M. E.; Aivazis, M.

    2004-12-01

    Solid earth geophysicists have a long tradition of writing scientific software to address a wide range of problems. In particular, computer simulations came into wide use in geophysics during the decade after the plate tectonic revolution. Solution schemes and numerical algorithms that developed in other areas of science, most notably engineering, fluid mechanics, and physics, were adapted with considerable success to geophysics. This software has largely been the product of individual efforts and although this approach has proven successful, its strength for solving problems of interest is now starting to show its limitations as we try to share codes and algorithms or when we want to recombine codes in novel ways to produce new science. With funding from the NSF, the US community has embarked on a Computational Infrastructure for Geodynamics (CIG) that will develop, support, and disseminate community-accessible software for the greater geodynamics community from model developers to end-users. The software is being developed for problems involving mantle and core dynamics, crustal and earthquake dynamics, magma migration, seismology, and other related topics. With a high level of community participation, CIG is leveraging state-of-the-art scientific computing into a suite of open-source tools and codes. The infrastructure that we are now starting to develop will consist of: (a) a coordinated effort to develop reusable, well-documented and open-source geodynamics software; (b) the basic building blocks - an infrastructure layer - of software by which state-of-the-art modeling codes can be quickly assembled; (c) extension of existing software frameworks to interlink multiple codes and data through a superstructure layer; (d) strategic partnerships with the larger world of computational science and geoinformatics; and (e) specialized training and workshops for both the geodynamics and broader Earth science communities. The CIG initiative has already started to

  1. Graded Carrier Concentration Absorber Profile for High Efficiency CIGS Solar Cells

    Directory of Open Access Journals (Sweden)

    Antonino Parisi

    2015-01-01

    Full Text Available We demonstrate an innovative CIGS-based solar cells model with a graded doping concentration absorber profile, capable of achieving high efficiency values. In detail, we start with an in-depth discussion concerning the parametrical study of conventional CIGS solar cells structures. We have used the wxAMPS software in order to numerically simulate cell electrical behaviour. By means of simulations, we have studied the variation of relevant physical and chemical parameters—characteristic of such devices—with changing energy gap and doping density of the absorber layer. Our results show that, in uniform CIGS cell, the efficiency, the open circuit voltage, and short circuit current heavily depend on CIGS band gap. Our numerical analysis highlights that the band gap value of 1.40 eV is optimal, but both the presence of Molybdenum back contact and the high carrier recombination near the junction noticeably reduce the crucial electrical parameters. For the above-mentioned reasons, we have demonstrated that the efficiency obtained by conventional CIGS cells is lower if compared to the values reached by our proposed graded carrier concentration profile structures (up to 21%.

  2. ZnMgO by APCVD Enabling High-Performance Mid-bandgap CIGS on Polyimide Modules: October 2009--October 2010

    Energy Technology Data Exchange (ETDEWEB)

    Woods, L.

    2011-04-01

    This Pre-Incubator project was designed to increase the 'real world' CIGS based photovoltaic module performance and decrease the Levelized Cost of Energy (LCOE) of systems utilizing those modules compared to our traditional CIGS based photovoltaic modules. This was enabled by a) increasing the CIGS bandgap and b) developing better matched device finishing layers to the mid-bandgap CIGS based photovoltaics; including window and buffer layers (and eventually the TCO). Incremental progress in the novel device performance was demonstrated throughout the program, and ultimately achieved performance results that exceeded the milestones ahead of schedule. Metal-oxide buffer layer devices with mid-bandgap CIGS alloys on polyimide substrates were produced with efficiencies of over 12%. Corresponding mid-bandgap devices with CdS buffers produced over 13% efficient devices. Furthermore, no obvious degradation in the device performance has been observed to date, after proper storage ambient of the different types of unencapsulated devices were identified.

  3. Improvement in efficiency of solar cell by removing Cu2-xSe from CIGS film surface

    Institute of Scientific and Technical Information of China (English)

    Li Wei; Sun Yun; Liu Wei; Li Feng-Yan; Zhou Lin

    2006-01-01

    CIGS thin films are deposited by sputtering and selenization.The synthesis of semiconducting polycrystalline thin films and characteristics of devices based on the CIGS absorbing layers are investigated.Their microstructures are characterized by X-ray diffraction and Raman spectroscopy.The results reveal that there exist metallic Cu2-xSe compounds in CIGS film surfaces and the compounds are thought to be responsible for the degradation of the open circuit voltage of solar cells.The optimization of selenization temperature profile and copper content in the precursor surfaces is studied,concluding that the conversion efficiency may be improved by removing metallic Cu2-xSe compounds from the surfaces of CIGS thin films.

  4. One-pot electrodeposition, characterization and photoactivity of stoichiometric copper indium gallium diselenide (CIGS) thin films for solar cells.

    Science.gov (United States)

    Harati, Mohammad; Jia, Jia; Giffard, Kévin; Pellarin, Kyle; Hewson, Carly; Love, David A; Lau, Woon Ming; Ding, Zhifeng

    2010-12-14

    Herein we report the one-pot electrodeposition of copper indium gallium diselenide, CuIn(1-x)Ga(x)Se(2) (CIGS), thin films as the p-type semiconductor in an ionic liquid medium consisting of choline chloride/urea eutectic mixture known as Reline. The thin films were characterized by scanning electron microscopy with energy dispersive X-ray analysis, transmission electron microscopy, X-ray photoelectron spectroscopy, Raman microspectroscopy, and UV-visible spectroscopy. Based on the results of the characterizations, the electrochemical bath recipe was optimized to obtain stoichiometric CIGS films with x between 0.2 and 0.4. The chemical activity and photoreactivity of the optimized CIGS films were found to be uniform using scanning electrochemical microscopy and scanning photoelectrochemical microscopy. Low-cost stoichiometric CIGS thin films in one-pot were successfully fabricated.

  5. Synthesis of colloidal nanoscaled copper-indium-gallium-selenide (CIGS) particles for photovoltaic applications.

    Science.gov (United States)

    Mousavi, S H; Müller, T S; de Oliveira, P W

    2012-09-15

    In this work, Cu(In,Ga)Se(2) (CIGS) nanoparticles were synthesized using a wet chemical method. The method is based on a non-vacuum thermal process that does not use selenization. The effects of temperature, source materials, and growth conditions on the phase and particle size were investigated. X-ray diffraction results confirm the formation of a tetragonal CIGS structure as the main phase with the purity more than 99% obtained by energy-dispersive X-ray spectroscopy (EDX). The morphology and size of the samples were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Using these methods, 20-80nm particles were obtained. Through measurements of the absorption spectra of CIGS nanoparticles, the band gap of the synthesized material was determined to be about 1.44eV, which corresponds to an acceptable wavelength region for absorber layers in solar cells.

  6. TEMPERATUREEFFECT OFELECTRICALPROPERTIES OF CIGS SOLAR CELL

    Directory of Open Access Journals (Sweden)

    A. M. Ferouani

    2015-07-01

    Full Text Available In this paper we are interested in studying the copper–indium–gallium–selenium (CIGS solar cells sandwiched between cadmium sulfide (CdS and ZnO as buffer layers, and Molybdenum (Mo. Thus, we report our simulation results using the capacitance simulator (SCAPS in terms of layer thickness, absorber layer band gap and operating temperature to find out the optimum choice. An efficiency of 20.61% (with Voc of 635.2mV, Jsc of 44.08 mA/cm2 and fill factor of 0.73 has been achieved with CdS used as buffer layer as the reference case. It is also found that the high efficiency CIGS cells with the low temperature were a very high efficiency conversion.

  7. Thin film CIGS solar cells with a novel low cost process - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Tiwari, A. N.; Romanyuk, Y.

    2010-01-15

    Novel manufacturing routes for efficient and low-cost Cu(In,Ga)Se{sub 2} (called CIGS) thin film solar cells are explored and patented. CIGS has proven its suitability for highly efficient and extremely stable solar cells. The low-cost methods allow impurity free material synthesis, fast large-area deposition, high material utilization and a very short energy payback time with drastically lower manufacturing costs. Two non-vacuum, solution-based approaches are investigated to deposit thin layers of CIGS. The first approach considers incorporation of copper into indium gallium selenide precursor layers by ion-exchange from aqueous or organic solutions. Organic solutions provide faster copper incorporation and do not corrode the metal back contact. Solar cells processed from selenized precursor films exhibit efficiencies of up to 4.1%. The second approach with paste coating of inorganic salt solution results in a solar cell efficiency of 4% (record 6.7%), where further improvements are hindered by the presence of the residual carbon layer. Using alternative organic binders, pre-deposited selenium layers, non-binder recipes helps to avoid the carbon layer although the obtained layers are inhomogeneous and contain impurity phases. A patent for the ion-exchange approach is pending, and the obtained research results on the paste coating approach will be scrutinized during new European FP7 project 'NOVA-CIGS'. (authors)

  8. Preparations for low-cost silica substrate of CIGS solar cell

    Science.gov (United States)

    Hsu, Ming-Seng; Chang, Chung Chih; Cheng, Hsiang Hshi; Ouyang, Yueh; Der Sheu, Shinn

    2008-08-01

    The production of CuInGaSe2 (CIGS) solar cell is based on vacuum processes, which requires a high manufacturing temperature and high cost. Our result show a simple method has been developed to prepare the silica substrates of CIGS solar cell. It's synthesized by sol-gel process from tetraethylorthosilicate (TEOS), methanol (CH3OH) and pure water (both ion-exchange and distillation) in the presence of ammonia as catalyst. The preparation procedure was elaborated as the flexible sequence to control chemical composition and properties of the particles in sol-gel-derived silica substrate. The morphology, particle size, and size distribution of CIGS substrate were characterized with dynamic light scattering (DLS) and atomic force microscopy (AFM). The results of AFM morphology and statistic evidence we find an easy way, non-vacuum and low temperature processes, to successfully prepare the CIGS solar cell substrates with surface roughness below 3 nm. It is powerful the advance study in low cost solar cell.

  9. Solution-deposited CIGS thin films for ultra-low-cost photovoltaics

    Science.gov (United States)

    Eldada, Louay A.; Hersh, Peter; Stanbery, Billy J.

    2010-09-01

    We describe the production of photovoltaic modules with high-quality large-grain copper indium gallium selenide (CIGS) thin films obtained with the unique combination of low-cost ink-based precursors and a reactive transfer printing method. The proprietary metal-organic inks contain a variety of soluble Cu-, In- and Ga- multinary selenide materials; they are called metal-organic decomposition (MOD) precursors, as they are designed to decompose into the desired precursors. Reactive transfer is a two-stage process that produces CIGS through the chemical reaction between two separate precursor films, one deposited on the substrate and the other on a printing plate in the first stage. In the second stage, these precursors are rapidly reacted together under pressure in the presence of heat. The use of two independent thin films provides the benefits of independent composition and flexible deposition technique optimization, and eliminates pre-reaction prior to the synthesis of CIGS. In a few minutes, the process produces high quality CIGS films, with large grains on the order of several microns, and preferred crystallographic orientation, as confirmed by compositional and structural analysis by XRF, SIMS, SEM and XRD. Cell efficiencies of 14% and module efficiencies of 12% were achieved using this method. The atmospheric deposition processes include slot die extrusion coating, ultrasonic atomization spraying, pneumatic atomization spraying, inkjet printing, direct writing, and screen printing, and provide low capital equipment cost, low thermal budget, and high throughput.

  10. 7 CFR 1466.27 - Conservation Innovation Grants (CIG).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Conservation Innovation Grants (CIG). 1466.27 Section... PROGRAM Contracts and Payments § 1466.27 Conservation Innovation Grants (CIG). (a) Definitions. In.... (3) Grant Review Board consists of the NRCS Deputy Chief for Programs, Deputy Chief for Science...

  11. CIGS Material and Device Stability: A Processing Perspective (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Ramanathan, K.

    2012-03-01

    This is a general overview of CIGS material and device fundamentals. In the first part, the basic features of high efficiency CIGS absorbers and devices are described. In the second part, some examples of previous collaboration with Shell Solar CIGSS graded absorbers and devices are shown to illustrate how process information was used to correct deviations and improve the performance and stability.

  12. Dynamics of the isolated galaxy CIG 0314

    CERN Document Server

    Verley, S; Repetto, P; Gabbasov, R; Verdes-Montenegro, L; Bergond, G; Fuentes-Carrera, I; Durbala, A

    2009-01-01

    In the context of the AMIGA project, we used Fabry-Perot observations in order to study the dynamics of the ionised gas in the isolated galaxy CIG 0314. From the Halpha observations, we could obtain the velocity field and rotation curve of the galaxy. A detail analysis of the velocity field is done in order to understand the kinematics of the gas to gather clues on the mechanisms which favour or inhibit star formation, in particular along the bar. The visible and dark matter content can be reached, as well as an estimation of the mass of the galaxy.

  13. CIGS薄膜太阳能电池无镉缓冲层制备方法的研究现状%Deposition Technologies of Cd-Free Buffer Layers in Solar Cells Made of Copper Indium Gallium Diselenide Films

    Institute of Scientific and Technical Information of China (English)

    霍晓旭; 莫晓亮; 陈国荣

    2012-01-01

    The latest progress in the development of deposition technology of the Cd-free buffer layers in the solar cells made of copper indium gallium diselenide(CIGS) films was tentatively reviewed.The discussions focused on three topics: first, the film growth techniques and related properties of the three alternative Cd-free buffer layer materials (In2S3,ZnS,and Zn1-xMgxO) ; next,the possible impacts of the three alternative films and their deposition techniques on the fabrication and performance of the solar cells; finally, the development trends of the Cd-free layers in fabricating the CIGS solar cells.The strengths and weaknesses of the techniques, including the chemical bath deposition(CBD) , atomic layer deposition (AID) and sputtering depositions, on industrial scale production were evaluated in a thought-provoking way. We suggest that the sputtering deposition be most feasible to large scale industrial production. The technical problems to be solved were also discussed.%回顾了近年来CIGS薄膜太阳能电池无镉缓冲层的研究进展;着重介绍了In2S3,ZnS,Zn1-xMgxO三种可替代CdS缓冲层材料的常用制备方法及相关特性,并且对应给出了每种材料和方法获得的电池组件效率.展望了无镉缓冲层的发展前景,分析了化学水浴、原子层沉积、溅射三种缓冲层沉积技术各自在大规模工业化应用中的优劣势.认为溅射沉积技术是现阶段最理想的工业化制备技术,同时指出了无镉缓冲层在大规模工业化应用中亟需解决的问题.

  14. 2D - Finite element model of a CIGS module

    Energy Technology Data Exchange (ETDEWEB)

    Janssen, G.J.M.; Slooff, L.H.; Bende, E.E. [ECN Solar Energy, Petten (Netherlands)

    2012-09-15

    The performance of thin-film CIGS modules is often limited due to inhomogeneities in CIGS layers. A 2-dimensional Finite Element Model for CIGS modules is demonstrated that predicts the impact of such inhomogeneities on the module performance. Results are presented of a module with a region of poor diode characteristics. It is concluded that according to this model the effects of poor diodes depend strongly on their location in the module and on their dispersion over the module surface. Due to its generic character the model can also be applied to other series connections of photovoltaic cells.

  15. Development of Enhanced Window layers for CIGS Photovoltaic Devices

    Science.gov (United States)

    Alexander, J. Nicholas

    , had an alternative deposition chemistry investigated. This new chemistry replacing thiourea with N-methylthiourea was used in a chemical bath deposition (CBD). This new chemistry yielded more controlled growth kinetics with a wider processing window. The films grown using this chemistry were more uniform than those grown with the standard process using thiourea. These uniform films were shown to have more complete surface coverage at very thin layers ( 20-30 nm). The second study investigated commercial modules of crystalline silicon, CIGS, and CdTe based technologies with a total system capacity of approximately 100 kW. The system is fitted with current, voltage, temperature, irradiance, and a complete weather station. The purpose of the system is to investigate different panel technologies and monitoring challenges in northeast climates and to track their degradation over time. (Abstract shortened by ProQuest.).

  16. Characterization of 19.9% Efficient CIGS Absorbers: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Repins, I.; Contreras, M.; Romero, M.; Yan, Y.; Metzger, W.; Li, J.; Johnston, S.; Egass, B.; DeHart, C.; Scharf, J.; McCandless, B. E.; Noufi, R.

    2008-05-01

    This paper documents the properties of the world-record-efficiency CIGS solar cell by a variety of characterization techniques, with an emphasis on identifying near-surface properties associated with the modified processing.

  17. E-Cigs May Be 'Bridge' to Teens' Tobacco Use

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_163491.html E-Cigs May Be 'Bridge' to Teens' Tobacco Use ' ... 8, 2017 (HealthDay News) -- Nonsmoking teens who use e-cigarettes appear to be more likely to light ...

  18. Optical Metrology for CIGS Solar Cell Manufacturing and its Cost Implications

    Science.gov (United States)

    Sunkoju, Sravan Kumar

    Solar energy is a promising source of renewable energy which can meet the demand for clean energy in near future with advances in research in the field of photovoltaics and cost reduction by commercialization. Availability of a non-contact, in-line, real time robust process control strategies can greatly aid in reducing the gap between cell and module efficiencies, thereby leading to cost-effective large-scale manufacturing of high efficiency CIGS solar cells. In order to achieve proper process monitoring and control for the deposition of the functional layers of CuIn1-xGaxSe 2 (CIGS) based thin film solar cell, optical techniques such as spectroscopic reflectometry and polarimetry are advantageous because they can be set up in an unobtrusive manner in the manufacturing line, and collect data in-line and in-situ. The use of these techniques requires accurate optical models that correctly represent the properties of the layers being deposited. In this study, Spectroscopic ellipsometry (SE) has been applied for the characterization of each individual stage of CIGS layers deposited using the 3-stage co-evaporation process along with the other functional layers. Dielectric functions have been determined for the energy range from 0.7 eV to 5.1 eV. Critical-point line-shape analysis was used in this study to determine the critical point energies of the CIGS based layers. To control the compositional and thickness uniformity of all the functional layers during the fabrication of CIGS solar cells over large areas, multilayer photovoltaics (PV) stack optical models were developed with the help of extracted dielectric functions. In this study, mapping capability of RC2 spectroscopic ellipsometer was used to map all the functional layer thicknesses of a CIGS solar cell in order to probe the spatial non-uniformities that can affect the performance of a cell. The optical functions for each of the stages of CIGS 3-stage deposition process along with buffer layer and transparent

  19. Vaping cannabis (marijuana): parallel concerns to e-cigs?

    OpenAIRE

    Budney, Alan J.; Sargent, James D.; Lee, Dustin C.

    2015-01-01

    The proliferation of vaporization (‘vaping’) as a method for administering cannabis raises many of the same public health issues being debated and investigated in relation to e-cigarettes (e-cigs). Good epidemiological data on the prevalence of vaping cannabis are not yet available, but with current trends towards societal approval of medicinal and recreational use of cannabis, the pros and cons of vaping cannabis warrant study. As with e-cigs, vaping cannabis portends putative health benefit...

  20. Mechanochemically Synthesized CIGS Nanocrystalline Powder for Solar Cell Application

    Directory of Open Access Journals (Sweden)

    Bharati Rehani

    2013-05-01

    Full Text Available Copper Indium Gallium Diselenide (CIGS is a compound semiconductor material from the group of I-III-VI. The material is a solid solution of copper, indium and selenium (CIS and copper, gallium and selenium with an empirical formula of CuIn(1 – xGaxSe2, where 0  x  1. CIGS has an exceptionally high absorption coefficient of more than 105 cm – 1 for 1.5 eV. Solar cells prepared from absorber layers of CIGS materials have shown an efficiency higher than 20 %. CuIn(1 – xGaxSe2 (x  0.3 nanocrystalline compound was mechanochemically synthesized by high-energy milling in a planetary ball mill. The phase identification and crystallite size of milled powders at different time intervals were carried out by X-ray diffraction (XRD. The XRD analysis indicates chalcopyrite structure and the crystallite size of about 10 nm of high-energy milled CIGS powder after two and half hours of milling. An attempt for preparing the thin film from CIGS nanocrystalline powder was carried out using the flash evaporation technique. Scanning electron microscopy (SEM reveals uniform distribution of CIGS particles in thin film.

  1. Magnetically engineered Cd-free quantum dots as dual-modality probes for fluorescence/magnetic resonance imaging of tumors.

    Science.gov (United States)

    Ding, Ke; Jing, Lihong; Liu, Chunyan; Hou, Yi; Gao, Mingyuan

    2014-02-01

    Magnetically engineered Cd-free CuInS2@ZnS:Mn quantum dots (QDs) were designed, synthesized, and evaluated as potential dual-modality probes for fluorescence and magnetic resonance imaging (MRI) of tumors in vivo. The synthesis of Mn-doped core-shell structured CuInS2@ZnS mainly comprised three steps, i.e., the preparation of fluorescent CuInS2 seeds, the particle surface coating of ZnS, and the Mn-doping of the ZnS shells. Systematic spectroscopy studies were carried out to illustrate the impacts of ZnS coating and the following Mn-doping on the optical properties of the QDs. In combination with conventional fluorescence, fluorescence excitation, and time-resolved fluorescence measurements, the structure of CuInS2@ZnS:Mn QDs prepared under optimized conditions presented a Zn gradient CuInS2 core and a ZnS outer shell, while Mn ions were mainly located in the ZnS shell, which well balanced the optical and magnetic properties of the resultant QDs. For the following in vivo imaging experiments, the hydrophobic CuInS2@ZnS:Mn QDs were transferred into water upon ligand exchange reactions by replacing the 1-dodecanethiol ligand with dihydrolipoic acid-poly(ethylene glycol) (DHLA-PEG) ligand. The MTT assays based on HeLa cells were carried out to evaluate the cytotoxicity of the current Cd-free CuInS2@ZnS:Mn QDs for comparing with that of water soluble CdTe QDs. Further in vivo fluorescence and MR imaging experiments suggested that the PEGylated CuInS2@ZnS:Mn QDs could well target both subcutaneous and intraperitoneal tumors in vivo.

  2. Effects of selenization conditions on densification of Cu(In,Ga)Se2 (CIGS) thin films prepared by spray deposition of CIGS nanoparticles

    Science.gov (United States)

    Ahn, SeJin; Kim, Ki Hyun; Yun, Jae Ho; Yoon, Kyung Hoon

    2009-06-01

    Spray deposited porous CIGS nanoparticle-derived thin films were selenized in a two zone rapid thermal annealing furnace and effects of various selenization parameters including Se evaporation temperature, flow rate of carrier gas, and substrate temperature on densification of the CIGS layers were investigated. It was found that higher Se supply to CIGS nanoparticles either by increasing Se evaporation temperature or by increasing the flow rate of carrier gas resulted in larger CIGS grains with higher degree of crystallinity, while it also induced formation of a thicker MoSe2 layer in-between CIGS and Mo which resulted in partial detachment of CIGS/MoSe2/Mo layers from the glass substrate. Densification of CIGS layer by growth of nanoparticles and formation of thick MoSe2 were explained by a liquid Se assisted reaction rather than by a vapor phase Se assisted reaction.

  3. New buffer layer materials for CIGS solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Gruhn, Thomas; Felser, Claudia [Institute of Inorganic and Analytical Chemistry, Johannes Gutenberg University, Mainz (Germany); Kieven, David [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Berlin (Germany)

    2009-07-01

    The compound semiconductor CuIn{sub x}Ga{sub (1-x)}Se{sub 2} (CIGSE) are used as absorber material in thin-film photovoltaic cells. In conventional CIGSE based solar cells a thin CdS layer (buffer) significantly improves the photovoltaic performance and efficiencies up to 19.9% have been realized. Since Cd is a toxic heavy metal there is a demand for suitable substitute materials. The first requirements for these materials are an adequate band gap, a crystal structure compatible to that of CIGSE, and an n-type conductivity. An interesting class of materials are half-Heuslers, which are ternary compounds with a C1b MgAgAs structure. For many half-Heusler compounds the crystal structure matches well with the layer of the tetragonal CIGS unit cell. Using ab initio calculations based on B3LYP hybrid functionals, we have studied electronic properties of the most promising half-Heusler materials. Our results affirm the band gap rule for 8-electron half- Heuslers presented.

  4. Characterization of Al2O3 as CIGS surface passivation layer in high-efficiency CIGS solar cells

    OpenAIRE

    Joel, Jonathan

    2014-01-01

    In this thesis, a novel method of reducing the rear surface recombination in copper indium gallium (di) selenide (CIGS) thin film solar cells, using atomic layer deposited (ALD) Al2O3, has been evaluated via qualitative opto-electrical characterization. The idea stems from the silicon (Si) industry, where rear surface passivation layers are used to boost the open-circuit voltage and, hence, the cell efficiency. To enable a qualitative assessment of the passivation effect, Al/Al2O3/CIGS metal-...

  5. Lessons learned from NMSG-085 CIG Land Operation demonstration

    NARCIS (Netherlands)

    Gautreau, B.; Remmersmann, T.; Henderson, H.C.; Reus, N.M. de; Khimeche, L.; Pedersen, E.; Lillesoe, J.; Liberg, D.

    2013-01-01

    This paper presents the experience gained during demonstrations carried out between Denmark, France, Germany, the Netherlands and Spain under the umbrella of the NMSG-085 / CIG Land Operation group. The demonstration, also presented in this paper, focuses on command post exercise training. It highli

  6. Metal-assisted chemical etching of CIGS thin films for grain size analysis

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Chaowei [Research and Development Centre, Hanergy Thin Film Power Group Limited, Chengdu (China); Loi, Huu-Ha; Duong, Anh; Parker, Magdalena [Failure Analysis Department, MiaSole Hi-Tech Corp., Santa Clara, CA (United States)

    2016-09-15

    Grain size of the CIGS absorber is an important monitoring factor in the CIGS solar cell manufacturing. Electron backscatter diffraction (EBSD) analysis is commonly used to perform CIGS grain size analysis in the scanning electron microscope (SEM). Although direct quantification on SEM image using the average grain intercept (AGI) method is faster and simpler than EBSD, it is hardly applicable on CIGS thin films. The challenge is that, not like polycrystalline silicon, to define grain boundaries by selective chemical etching is not easily realizable for the multi-component CIGS alloy. In this Letter, we present direct quantification of CIGS thin film grain size using the AGI method by developing metal-assisted wet chemical etching process to define CIGS grain boundaries. The calculated value is similar to EBSD result. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Fabrication, Electrical Characterization and Simulation of Thin Film Solar Cells: CdTe and CIGS Materials

    OpenAIRE

    Es'haghi Gorji, Nima

    2014-01-01

    CdTe and Cu(In,Ga)Se2 (CIGS) thin film solar cells are fabricated, electrically characterized and modelled in this thesis. We start from the fabrication of CdTe thin film devices where the R.F. magnetron sputtering system is used to deposit the CdS/CdTe based solar cells. The chlorine post-growth treatment is modified in order to uniformly cover the cell surface and reduce the probability of pinholes and shunting pathways creation which, in turn, reduces the series resistance. The deionized wat...

  8. Interaction of ultra-short laser pulses with CIGS and CZTSe thin films

    Science.gov (United States)

    Gečys, P.; Markauskas, E.; Dudutis, J.; Račiukaitis, G.

    2014-01-01

    The thin-film solar cell technologies based on complex quaternary chalcopyrite and kesterite materials are becoming more attractive due to their potential for low production costs and optimal spectral performance. As in all thin-film technologies, high efficiency of small cells might be maintained with the transition to larger areas when small segments are interconnected in series to reduce photocurrent and related ohmic losses in thin films. Interconnect formation is based on the three scribing steps, and the use of a laser is here crucial for performance of the device. We present our simulation and experimental results on the ablation process investigations in complex CuIn1- x Ga x Se2 (CIGS) and Cu2ZnSn(S,Se)4 (CZTSe) cell's films using ultra-short pulsed infrared (~1 μm) lasers which can be applied to the damage-free front-side scribing processes. Two types of processes were investigated—direct laser ablation of ZnO:Al/CIGS films with a variable pulse duration of a femtosecond laser and the laser-induced material removal with a picosecond laser in the ZnO:Al/CZTSe structure. It has been found that the pulse energy and the number of laser pulses have a significantly stronger effect on the ablation quality in ZnO:Al/CIGS thin films rather than the laser pulse duration. For the thin-film scribing applications, it is very important to carefully select the processing parameters and use of ultra-short femtosecond pulses does not have a significant advantage compared to picosecond laser pulses. Investigations with the ZnO:Al/CZTSe thin films showed that process of the absorber layer removal was triggered by a micro-explosive effect induced by high pressure of sublimated material due to a rapid temperature increase at the molybdenum-CZTSe interface.

  9. Modelling Defects Acceptors And Determination Of Electric Model From The Nyquist Plot And Bode In Thin Film CIGS

    Directory of Open Access Journals (Sweden)

    Demba Diallo

    2015-08-01

    Full Text Available Abstract The performance of the chalcopyrite material CuInGaSe2 CIGS used as an absorber layer in thin-film photovoltaic devices is significantly affected by the presence of native defects. Multivalent defects e.g. double acceptors or simple acceptor are important immaterial used in solar cell production in general and in chalcopyrite materials in particular. We used the thin film solar cell simulation software SCAPS to enable the simulation of multivalent defects with up to five different charge states.Algorithms enabled us to simulate an arbitrary number of possible states of load. The presented solution method avoids numerical inaccuracies caused by the subtraction of two almost equal numbers. This new modelling facility is afterwards used to investigate the consequences of the multivalent character of defects for the simulation of chalcopyrite based CIGS. The capacitance increase with the evolution of the number of defects C- f curves have found to have defect dependence.

  10. Vaping cannabis (marijuana): parallel concerns to e-cigs?

    Science.gov (United States)

    Budney, Alan J; Sargent, James D; Lee, Dustin C

    2015-11-01

    The proliferation of vaporization ('vaping') as a method for administering cannabis raises many of the same public health issues being debated and investigated in relation to e-cigarettes (e-cigs). Good epidemiological data on the prevalence of vaping cannabis are not yet available, but with current trends towards societal approval of medicinal and recreational use of cannabis, the pros and cons of vaping cannabis warrant study. As with e-cigs, vaping cannabis portends putative health benefits by reducing harm from ingesting toxic smoke. Indeed, vaping is perceived and being sold as a safer way to use cannabis, despite the lack of data on the health effects of chronic vaping. Other perceived benefits include better taste, more efficient and intense effects and greater discretion which allows for use in more places. Unfortunately, these aspects of vaping could prompt an increased likelihood of trying cannabis, earlier age of onset, more positive initial experiences, and more frequent use, thereby increasing the probability of problematic use or addiction. Sales and marketing of vaping devices with no regulatory guidelines, especially related to advertising or product development targeting youth, parallels concerns under debate related to e-cigs and youth. Thus, the quandary of whether or not to promote vaping as a safer method of cannabis administration for those wishing to use cannabis, and how to regulate vaping and vaping devices, necessitates substantial investigation and discussion. Addressing these issues in concert with efforts directed towards e-cigs may save time and energy and result in a more comprehensive and effective public health policy on vaping.

  11. An analysis of glass–glass CIGS manufacturing costs

    Energy Technology Data Exchange (ETDEWEB)

    Horowitz, Kelsey A. W.; Fu, Ran; Woodhouse, Michael

    2016-09-01

    This article examines current cost drivers and potential avenues to reduced cost for monolithic, glass-glass Cu(In,Ga)(Se,S)2 (CIGS) modules by constructing a comprehensive bottom-up cost model. For a reference case where sputtering plus batch sulfurization after selenization (SAS) is employed, we compute a manufacturing cost of $69/m2 if the modules are made in the United States at a 1 GW/year production volume. At 14% module efficiency, this corresponds to a manufacturing cost of $0.49/WDC and a minimum sustainable price (MSP) of $0.67/WDC. We estimate that MSP could vary within +/-20% of this value given the range of quoted input prices, and existing variations in module design, manufacturing processes, and manufacturing location. Potential for reduction in manufacturing costs to below $0.40/WDC may be possible if average production module efficiencies can be increased above 17% without increasing $/m2 costs; even lower costs could be achieved if $/m2 costs could be reduced, particularly via innovations in the CIGS deposition process or balance-of-module elements. We present the impact on cost of regional factors, CIGS deposition method, device design, and price fluctuations. One metric of competitiveness-levelized cost of energy (LCOE) -- is also assessed for several U.S. locations and compared to that of standard multi-crystalline silicon (m(c-Si)) and cadmium telluride (CdTe).

  12. A Novel Semiconductor CIGS Photovoltaic Material and Thin-Film ED Technology

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to achieve low-cost high-efficiency thin-film solar cells, a novel Semiconductor Photovoltaic (PV) active material CuIn1-xGaxSe2 (CIGS) and thin-film Electro-Deposition (ED) technology is explored. Firstly,the PV materials and technologies is investigated, then the detailed experimental processes of CIGS/Mo/glass structure by using the novel ED technology and the results are reported. These results shows that high quality CIGS polycrystalline thin-films can be obtained by the ED method, in which the polycrystalline CIGS is definitely identified by the (112), (204, 220) characteristic peaks of the tetragonal structure, the continuous CIGS thin-film layers with particle average size of about 2μm of length and around 1.6μm of thickness. The thickness and solargrade quality of CIGS thin-films can be produced with good repeatability. Discussion and analysis on the ED technique, CIGS energy band and sodium (Na) impurity properties, were also performed. The alloy CIGS exhibits not only increasing band-gap with increasing x, but also a change in material properties that is relevant to the device operation. The beneficial impurity Na originating from the low-cost soda-lime glass substrate becomes one prerequisite for high quality CIGS films. These novel material and technology are very useful for low-cost high-efficiency thin-film solar cells and other devices.

  13. 铜铟镓硒(CIGS)薄膜太阳能电池的研究进展%Progress in Research of CIGS Thin Film Solar Cells

    Institute of Scientific and Technical Information of China (English)

    王波; 刘平; 李伟; 马凤仓; 刘新宽; 陈小红

    2011-01-01

    综述了CIGS薄膜太阳能电池近年来的研究进展.概述了CIGS薄膜的组织结构、性能特性及其之间的联系;介绍了CIGS薄膜吸收层的多种制备方法,如多元共蒸发法、溅射后硒化法、电沉积法、喷涂高温分解法等;概述了Na掺杂对CIGS电池性能的促进作用及其机理;总结了柔性衬底CIGS薄膜太阳能电池的研究情况;最后从理论和实验研究方面展望了CIGS薄膜太阳能电池的研究方向.%The recent progress of CIGS thin film solar cells is reviewed. The microstructure, properties and their relations of CIGS are summarized. Various preparation methods of CIGS absorber layer, such as co-evaporation, selenization after sputtering, electrodeposition, and spray pyrolysis etc are introduced. The influence of doping Na in performance and its mechanism of CIGS cells are summarized. The research of flexible CIGS cells are summed up, and the theoretical and experimental research directions of CIGS thin film solar cells are finally prospected.

  14. Laser scribing of CIGS thin-film solar cell on flexible substrate

    Science.gov (United States)

    Hwang, David J.; Kuk, Seungkuk; Wang, Zhen; Fu, Shi; Zhang, Tao; Kim, Gayeon; Kim, Won Mok; Jeong, Jeung-hyun

    2017-01-01

    Laser scribing technology has been actively developed for thin-film solar cell fabrication taking a number of advantages over mechanical scribing. Its non-contact processing nature enables reliable and precise scribing processes. In particular, it is almost unavoidable to use laser scribing method for fabricating high-quality flexible thin-film solar cells. Despite the fundamental merits that laser scribing can offer, still a number of challenges should be addressed in order to replace the mechanical counterpart for wider range of thin-film solar cells. In this study, we explore optimal laser scribing conditions for copper-indium-gallium-selenide (CIGS) thin-film solar cells, especially based on flexible polyimide (PI) substrate in close comparison with that based on soda-lime glass substrate. Picosecond-pulsed laser of repetition rate up to 100 kHz and wavelength of 532 nm ( 12 ps temporal pulse width) was mainly tested, and scribing speed in the range of 0.01-1 m/s was examined with a few different laser focal spot diameters (27, 34, and 62 μm). Main focus of this study is in understanding distinct laser scribing mechanisms for flexible substrate configurations, thereby finding out intrinsic optimal processing parameters. One of the most critical requirements is to prevent possible damage or deformation of underlying thin-film layer(s) or PI substrate. Effect of microstructures of thin films (in particular, Mo and CIGS) on the scribing behavior was also examined. In order to further improve the performance of the scribing process and reduce the laser power budget as well, mild gas injection scheme was tested.

  15. Flexible CIGS solar cells and mini-modules (Flexcim)

    Energy Technology Data Exchange (ETDEWEB)

    Tiwari, A. N.

    2007-08-15

    This final report for the Swiss Federal Office of Energy (SFOE) reports on a project that has contributed significantly to further developments in the field of Cu(In,Ga)Se{sub 2} thin film solar cells on flexible substrates such as plastic and metal foils. Process optimisation at low temperature deposition conditions is reported on that have resulted in a new world record of the highest achieved solar conversion efficiency for any solar cell on plastic substrate: cells with an efficiency of 14.1% were obtained. Efficiencies beyond 15% are to be sought for by the reduction of reflection losses. The results obtained are presented in both illustrations and in graphical form. The authors state that more work, especially on up-scaling of CIGS deposition and further increasing the efficiency of flexible solar modules, is needed.

  16. Cost and Potential of Monolithic CIGS Photovoltaic Modules

    Energy Technology Data Exchange (ETDEWEB)

    Horowitz, Kelsey; Woodhouse, Michael

    2015-06-17

    A bottom-up cost analysis of monolithic, glass-glass Cu(In,Ga)(Se,S)2 (CIGS) modules is presented, illuminating current cost drivers for this technology and possible pathways to reduced cost. At 14% module efficiency, for the case of U.S. manufacturing, a manufacturing cost of $0.56/WDC and a minimum sustainable price of $0.72/WDC were calculated. Potential for reduction in manufacturing costs to below $0.40/WDC in the long-term may be possible if module efficiency can be increased without significant increase in $/m2 costs. The levelized cost of energy (LCOE) in Phoenix, AZ under different conditions is assessed and compared to standard c-Si.

  17. High-Efficiency CdTe and CIGS Thin-Film Solar Cells: Highlights and Challenges; Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Noufi, R.; Zweibel, K.

    2006-05-01

    Thin-film photovoltaic (PV) modules of CdTe and Cu(In,Ga)Se2 (CIGS) have the potential to reach cost-effective PV-generated electricity. These technologies have transitioned from the laboratory to the market place. Pilot production and first-time manufacturing are ramping up to higher capacity and enjoying a flood of venture-capital funding. CIGS solar cells and modules have achieved 19.5% and 13% efficiencies, respectively. Likewise, CdTe cells and modules have reached 16.5% and 10.2% efficiencies, respectively. Even higher efficiencies from the laboratory and from the manufacturing line are only a matter of time. Manufacturing-line yield continues to improve and is surpassing 85%. Long-term stability has been demonstrated for both technologies; however, some failures in the field have also been observed, emphasizing the critical need for understanding degradation mechanisms and packaging options. The long-term potential of the two technologies require R&D emphasis on science and engineering-based challenges to find solutions to achieve targeted cost-effective module performance, and in-field durability. Some of the challenges are common to both, e.g., in-situ process control and diagnostics, thinner absorber, understanding degradation mechanisms, protection from water vapor, and innovation in high-speed processing and module design. Other topics are specific to the technology, such as lower-cost and fast-deposition processes for CIGS, and improved back contact and voltage for CdTe devices.

  18. U.S. Surgeon General Calls for Crackdown on E-Cig Use in Teens

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_162443.html U.S. Surgeon General Calls for Crackdown on E-Cig ... product among American teens, according to a new U.S. Surgeon General's report that calls for a crackdown ...

  19. High efficiency CIGS and CIS cells with CVD ZnO buffer layers

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, L.C.; Lei, W.; Addis, F.W. [Washington State Univ./Tri-Cities, Richland, WA (United States); Shafarman, W.N. [Univ. of Delaware, Newark, DE (United States). Inst. of Energy Conversion; Contreras, M.A.; Ramanathan, K. [National Renewable Energy Lab., Golden, CO (United States)

    1997-12-31

    This paper describes investigations of CIS and CIGS solar cells with ZnO buffer layers. These studies are a result of a team effort between investigators at Washington State University (WSU), the Institute of Energy Conversion (IEC) and the National Renewable Energy Laboratory (NREL). Cells with ZnO buffer layers were fabricated with both Siemens CIS and NREL CIGS substrates. An active area efficiency of 13.95% was achieved for a ZnO/CIGS cell. ZnO buffer layers are grown by reacting a zinc adduct with tetrahydrofuran using a two-step approach: growth of approximately 100 {angstrom} of ZnO at 250 C; and then growth of 500 to 700 {angstrom} of ZnO at 100 C. The high temperature step is necessary to achieve good cell performance. It appears that exposure of CIGS to hydrogen at 250 C may remove contaminants and/or passivate recombination centers on the surface and subsurface regions.

  20. Integration of Solar Cells on Top of CMOS Chips - Part II: CIGS Solar Cells

    NARCIS (Netherlands)

    Lu, Jiwu; Liu, Wei; Kovalgin, Alexey Y.; Sun, Yun; Schmitz, Jurriaan

    2011-01-01

    We present the monolithic integration of deepsubmicrometer complementary metal–oxide–semiconductor (CMOS) microchips with copper indium gallium (di)selenide (CIGS) solar cells. Solar cells are manufactured directly on unpackaged CMOS chips. The microchips maintain comparable electronic performance,

  1. Effect of Rapid Thermal Annealing of CIGS Thin Film as an Absorber Layer

    Directory of Open Access Journals (Sweden)

    J.R. Ray

    2013-05-01

    Full Text Available The influence of rapid post-deposition thermal annealing (500 °C for 2 minutes on the CIGS thin films of different thicknesses (0.4 to 1.0 m has been investigated. The deposition of CIGS is carried out using the flash evaporation at the substrate temperature of 250 °C. The as-grown and annealed CIGS is characterized by XRD, SEM, EDS, TEM, optical transmission, reflection, and electrical measurements. Lowering the thickness of CIGS absorber shows the remarkable influence on crystal structure, surface morphology, and composition of the overall film. Further improvement was observed by the rapid annealing process. Cu-rich composition was observed for annealed CIGS thin film having a thickness below 0.6 μm, while for 1.0 m thickness the composition is slightly Cu-poor and the compactly packed faceted grains observed. Optical band gap near to 1.05 eV and the electrical resistivity in the order of 104 Ωcm shows its future use as an absorber layer for CIGS solar cell. Furthermore, an attempt of making CIGS / CdS hetero-structure shows ideal behavior of the Schottky hetero-structure with the ideality factor of 1.5.

  2. Expanding Thermal Plasma Chemical Vapour Deposition of ZnO:Al Layers for CIGS Solar Cells

    Directory of Open Access Journals (Sweden)

    K. Sharma

    2014-01-01

    Full Text Available Aluminium-doped zinc oxide (ZnO:Al grown by expanding thermal plasma chemical vapour deposition (ETP-CVD has demonstrated excellent electrical and optical properties, which make it an attractive candidate as a transparent conductive oxide for photovoltaic applications. However, when depositing ZnO:Al on CIGS solar cell stacks, one should be aware that high substrate temperature processing (i.e., >200°C can damage the crucial underlying layers/interfaces (such as CIGS/CdS and CdS/i-ZnO. In this paper, the potential of adopting ETP-CVD ZnO:Al in CIGS solar cells is assessed: the effect of substrate temperature during film deposition on both the electrical properties of the ZnO:Al and the eventual performance of the CIGS solar cells was investigated. For ZnO:Al films grown using the high thermal budget (HTB condition, lower resistivities, ρ, were achievable (~5 × 10−4 Ω·cm than those grown using the low thermal budget (LTB conditions (~2 × 10−3 Ω·cm, whereas higher CIGS conversion efficiencies were obtained for the LTB condition (up to 10.9% than for the HTB condition (up to 9.0%. Whereas such temperature-dependence of CIGS device parameters has previously been linked with chemical migration between individual layers, we demonstrate that in this case it is primarily attributed to the prevalence of shunt currents.

  3. Stability of TCO window layers for thin-film CIGS solar cells upon damp heat exposures: part II

    Science.gov (United States)

    Sundaramoorthy, R.; Pern, F. J.; DeHart, C.; Gennett, T.; Meng, F. Y.; Contreras, M.; Gessert, T.

    2009-08-01

    Long-term performance reliability is essential for any photovoltaic module to become established in the PV market. Reliability is characterized based on many factors, one of the most important being the capability of the module to be resistant to moisture at elevated temperatures. This work continues our efforts to search for a high-performance and high-stability transparent conducting oxide (TCO) window layer for CuInGaSe2 (CIGS) devices. In this experimental study, we compared the optical, electrical, and structural stability of various TCOs deposited on glass, including single-layer Al-doped ZnO (AZO), bilayer intrinsic-/Al-doped ZnO (BZO), B-doped ZnO (ZnO:B), amorphous In2O3:SnO2 (ITO), and amorphous In2O3:ZnO (IZO). The samples were exposed to damp heat (DH) at 85°C and 85% relative humidity (RH) and were characterized periodically. The results showed that all ZnO-based TCOs are more sensitive to moisture with substantial electrical degradation and apparent optical changes than the ITO and IZO. The amorphous IZO showed peculiar behavior in electrical property, and exhibited structural change with the appearance of some finite crystallinity after DH >220 h. The results from this experimental series will assist in determining the best-performing TCO for CIGS solar cells.

  4. Suppressing lossy-film-induced angular mismatches between reflectance and transmittance extrema: optimum optical designs of interlayers and AR coating for maximum transmittance into active layers of CIGS solar cells.

    Science.gov (United States)

    Chang, Yin-Jung

    2014-01-13

    The investigation of optimum optical designs of interlayers and antireflection (AR) coating for achieving maximum average transmittance (T(ave)) into the CuIn(1-x)Ga(x)Se2 (CIGS) absorber of a typical CIGS solar cell through the suppression of lossy-film-induced angular mismatches is described. Simulated-annealing algorithm incorporated with rigorous electromagnetic transmission-line network approach is applied with criteria of minimum average reflectance (R(ave)) from the cell surface or maximum T(ave) into the CIGS absorber. In the presence of one MgF2 coating, difference in R(ave) associated with optimum designs based upon the two distinct criteria is only 0.3% under broadband and nearly omnidirectional incidence; however, their corresponding T(ave) values could be up to 14.34% apart. Significant T(ave) improvements associated with the maximum-T(ave)-based design are found mainly in the mid to longer wavelengths and are attributed to the largest suppression of lossy-film-induced angular mismatches over the entire CIGS absorption spectrum. Maximum-T(ave)-based designs with a MgF2 coating optimized under extreme deficiency of angular information is shown, as opposed to their minimum-R(ave)-based counterparts, to be highly robust to omnidirectional incidence.

  5. Effect of yoghurt or yoghurt serum on microbial quality of cig kofte.

    Science.gov (United States)

    Dogan, Mahmut; Cankurt, Hasan; Toker, Omer Said; Yetim, Hasan; Sagdic, Osman

    2014-07-01

    Cig kofte, raw meatball is a traditionally produced meat product in Turkey and some other Middle East countries. It is prepared from mixtures of finely minced raw beef, bulgur, onions, various spices and tap water. Cig kofte is an uncooked product and popularly consumed with lettuce and lemon juice. In this study, yoghurt or yoghurt serum (YS) were added to the mixtures of cig kofte instead of tap water to reduce microbial risks of the raw meatball. Additionally, the effects of yoghurt and YS on some physicochemical characteristics of cig kofte were investigated. Cig kofte is generally consumed within a few hours after the preparation because of its raw nature. Also, it is generally sold under unhygienic conditions in restaurants and restaurant-like places. For this purpose, reducing of the microbial load of cig kofte is important. In the results, Escherichia coli and Listeria monocytogenes were not detected in any samples. While lactic acid bacteria count increased by addition of yoghurt and YS, the number of other microorganisms except for total aerobic mesophilic bacteria (TAMB) were decreased. The aw values and% moisture contents of the samples were varied between 0.88-0.94 and 46.25-49.72, respectively. The pH values of the samples were slightly changed during the storage of 24 h while no changes detected in the control samples during the storage. In conclusion, it can be suggested that using the yoghurt or YS instead of tap water in the preparation of cig kofte might ensure the microbial safety, increase the nutritional value and its flavour or aroma.

  6. AMIGA project: Quantification of the isolation of 950 CIG galaxies

    CERN Document Server

    Verley, S; Verdes-Montenegro, L; Combes, F; Sabater, J; Sulentic, J; Bergond, G; Espada, D; Lisenfeld, U; Odewahn, S C

    2009-01-01

    The role of the environment on galaxy evolution is still not fully understood. In order to quantify and set limits on the role of nurture one must identify and study a sample of isolated galaxies. The AMIGA project "Analysis of the Interstellar Medium of Isolated GAlaxies" is doing a multi-wavelength study of a large sample of isolated galaxies in order to examine their interstellar medium and star formation activity. We processed data for 950 galaxies from the Catalogue of Isolated Galaxies (CIG, Karachentseva 1973) and evaluated their isolation using an automated star-galaxy classification procedure (down to M_B ~17.5) on large digitised POSS-I fields surrounding each isolated galaxy (within a projected radius of at least 0.5 Mpc). We defined, compared and discussed various criteria to quantify the degree of isolation for these galaxies: e.g. Karachentseva's revised criterion, local surface density computations, estimation of the external tidal force affecting each isolated galaxy. We found galaxies violati...

  7. Sodium-Doped Molybdenum Targets for Controllable Sodium Incorporation in CIGS Solar Cells: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Mansfield, L. M.; Repins, I. L.; Glynn, S.; Carducci, M. D.; Honecker, D. M.; Pankow, J.; Young, M.; DeHart, C.; Sundaramoorthy, R.; Beall, C. L.; To, B.

    2011-07-01

    The efficiency of Cu(In,Ga)Se2 (CIGS) solar cells is enhanced when Na is incorporated in the CIGS absorber layer. This work examines Na incorporation in CIGS utilizing Na-doped Mo sputtered from targets made with sodium molybdate-doped (MONA) powder. Mo:Na films with varying thicknesses were sputtered onto Mo-coated borosilicate glass (BSG) or stainless steel substrates for CIGS solar cells. By use of this technique, the Na content of CIGS can be varied from near-zero to higher than that obtained from a soda-lime glass (SLG) substrate. Targets and deposition conditions are described. The doped Mo films are analyzed, and the resulting devices are compared to devices fabricated on Mo-coated SLG as well as Mo-coated BSG with NaF. Completed devices utilizing MONA exceeded 15.7% efficiency without anti-reflective coating, which was consistently higher than devices prepared with the NaF precursor. Strategies for minimizing adhesion difficulties are presented.

  8. Recycling of high purity selenium from CIGS solar cell waste materials.

    Science.gov (United States)

    Gustafsson, Anna M K; Foreman, Mark R StJ; Ekberg, Christian

    2014-10-01

    Copper indium gallium diselenide (CIGS) is a promising material in thin film solar cell production. To make CIGS solar cells more competitive, both economically and environmentally, in comparison to other energy sources, methods for recycling are needed. In addition to the generally high price of the material, significant amounts of the metals are lost in the manufacturing process. The feasibility of recycling selenium from CIGS through oxidation at elevated temperatures was therefore examined. During oxidation gaseous selenium dioxide was formed and could be separated from the other elements, which remained in solid state. Upon cooling, the selenium dioxide sublimes and can be collected as crystals. After oxidation for 1h at 800°C all of the selenium was separated from the CIGS material. Two different reduction methods for reduction of the selenium dioxide to selenium were tested. In the first reduction method an organic molecule was used as the reducing agent in a Riley reaction. In the second reduction method sulphur dioxide gas was used. Both methods resulted in high purity selenium. This proves that the studied selenium separation method could be the first step in a recycling process aimed at the complete separation and recovery of high purity elements from CIGS.

  9. Investigation of Some Transparent Metal Oxides as Damp Heat Protective Coating for CIGS Solar Cells: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Pern, F. J.; Yan, F.; Zaaunbrecher, B.; To, B.; Perkins, J.; Noufi, R.

    2012-10-01

    We investigated the protective effectiveness of some transparent metal oxides (TMO) on CIGS solar cell coupons against damp heat (DH) exposure at 85oC and 85% relative humidity (RH). Sputter-deposited bilayer ZnO (BZO) with up to 0.5-um Al-doped ZnO (AZO) layer and 0.2-um bilayer InZnO were used as 'inherent' part of device structure on CdS/CIGS/Mo/SLG. Sputter-deposited 0.2-um ZnSnO and atomic layer deposited (ALD) 0.1-um Al2O3 were used as overcoat on typical BZO/CdS/CIGS/Mo/SLG solar cells. The results were all negative -- all TMO-coated CIGS cells exhibited substantial degradation in DH. Combining the optical photographs, PL and EL imaging, SEM surface micro-morphology, coupled with XRD, I-V and QE measurements, the causes of the device degradations are attributed to hydrolytic corrosion, flaking, micro-cracking, and delamination induced by the DH moisture. Mechanical stress and decrease in crystallinity (grain size effect) could be additional degrading factors for thicker AZO grown on CdS/CIGS.

  10. Effects of Voltage-Bias Annealing on Metastable Defect Populations in CIGS and CZTSe Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, Steven P.; Johnston, Steve; Teeter, Glenn

    2016-11-21

    We report on voltage-bias annealing (VBA) experiments performed on CIGS and CZTSe solar cells. In these experiments, completed devices were annealed at moderate temperatures and subsequently quenched with continuously applied voltage bias. These treatments resulted in substantial reversible changes in device characteristics. Photovoltaic (PV) conversion efficiency of the CIGS device varied from below 3% to above 15%, with corresponding changes in CIGS hole density from ~1014 cm-3 to ~1017 cm-3. In the CZTSe device, open-circuit voltage varied from 289 meV to 446 meV, caused by an approximately factor of fifty change in the CZTSe hole density. We interpret these findings in terms of reversible changes to the metastable point-defect populations that control key properties in these materials. Implications for optimization of PV materials and connections to long-term stability of PV devices are discussed.

  11. Fabrication of CIGS thin films by using spray pyrolysis and post-selenization

    Science.gov (United States)

    Kim, Seong Yeon; Kim, JunHo

    2012-06-01

    We fabricated Cu(In1- x Ga x )Se2 ( x: 0 ˜ 0.4) thin films by using ultrasonic spray pyrolysis and post-selenization. First, we made Cu(In1- x Ga x )S2 ( x: 0 ˜ 0.4) films by ultrasonic spray pyrolysis under an air environment. Then, we converted as-sprayed Cu(In1- x Ga x )S2 (CIGS) films to Cu-(In1- x Ga x )Se2 (CIGSe) films through post-selenization. For all Ga fractions, the sprayed CIGS films were well recrystallized into poly-crystalline CIGSe films with a dominant (112) texture, which was confirmed by X-ray diffraction, Raman spectroscopy and energy dispersive X-ray analyses. This result indicates that CIGSe films with any amount of Ga substitution can be made by converting sprayed CIGS to CIGSe with post-selenization.

  12. Investigation of crystallization behavior of CIG-Se bi-layer thin films.

    Science.gov (United States)

    Park, Mi Sun; Sung, Shi-Joon; Kim, Dae-Hwan; Kang, Jin-Kyu

    2012-04-01

    Copper indium gallium diselenide (CIGSe) thin film was fabricated via a thermal treatment of GIG-Se bi-layer thin films. A CIG layer was prepared first, by a chemical solution deposition (CSD) process. The Se layer was deposited separately on the CIG layer by evaporation. The GIG-Se bi-layer then underwent a thermal treatment to cause a reaction between the two layers. In order to investigate the mechanism of CIG-Se bi-layer crystallization, the thermal treatment temperature was varied. The properties of the prepared CIGSe2 thin films were analyzed using X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectrometry (EDS), and UV-visible spectrophotometry.

  13. Interface properties of Cd-free buffer layers on on CIGSe thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Theisen, J.P.; Erfurth, F.; Weinhardt, L. [University of Wuerzburg (Germany). Experimental Physics VII; Duarte, R.; Baer, M. [Helmholtz Institut, Berlin (Germany); Niesen, T.; Palm, J. [Avancis GmbH, Muenchen (Germany); Barreau, N.; Couzinie-Devy, F.; Kessler, J. [Institut des Materiaux, Nantes (France); Reinert, F. [University of Wuerzburg (Germany). Experimental Physics VII; Forschungszentrum Karlsruhe GmbH (Germany). Gemeinschaftslabor fuer Nanoanalytik

    2010-07-01

    In order to replace the toxic Cadmium, the substitution of the CdS buffer layer in thin film solar cells based on Cu(In,Ga)(S,Se){sub 2} (CIGSSe) is of great interest. Alternative buffer layers like (In,Al){sub 2}S{sub 3}, In{sub 2}S{sub 3}, or (Zn{sub 1-x},Mg{sub x})O deposited by conventional sputter and chemical bath deposition techniques, have shown efficiencies close to or comparable to those of CdS containing solar cells. To understand the chemical and electronic properties of these buffer layers and its influence on the absorber, we studied the buffer-absorber interface using photoelectron spectroscopy (XPS, UPS) and inverse photoelectron spectroscopy (IPES). The combination of these non-destructive techniques provides detailed information about the chemical properties of the studied surface, as well as can be used for a direct determination of the conduction and valence band alignment at the heterojunction. Band-gap values at the surface as derived by UPS and IPES are also verified by electron energy loss spectroscopy (EELS). The results are discussed in conjunction with the respective cell parameters.

  14. CIG-DB: the database for human or mouse immunoglobulin and T cell receptor genes available for cancer studies

    Directory of Open Access Journals (Sweden)

    Furue Motoki

    2010-07-01

    Full Text Available Abstract Background Immunoglobulin (IG or antibody and the T-cell receptor (TR are pivotal proteins in the immune system of higher organisms. In cancer immunotherapy, the immune responses mediated by tumor-epitope-binding IG or TR play important roles in anticancer effects. Although there are public databases specific for immunological genes, their contents have not been associated with clinical studies. Therefore, we developed an integrated database of IG/TR data reported in cancer studies (the Cancer-related Immunological Gene Database [CIG-DB]. Description This database is designed as a platform to explore public human and murine IG/TR genes sequenced in cancer studies. A total of 38,308 annotation entries for IG/TR proteins were collected from GenBank/DDBJ/EMBL and the Protein Data Bank, and 2,740 non-redundant corresponding MEDLINE references were appended. Next, we filtered the MEDLINE texts by MeSH terms, titles, and abstracts containing keywords related to cancer. After we performed a manual check, we classified the protein entries into two groups: 611 on cancer therapy (Group I and 1,470 on hematological tumors (Group II. Thus, a total of 2,081 cancer-related IG and TR entries were tabularized. To effectively classify future entries, we developed a computational method based on text mining and canonical discriminant analysis by parsing MeSH/title/abstract words. We performed a leave-one-out cross validation for the method, which showed high accuracy rates: 94.6% for IG references and 94.7% for TR references. We also collected 920 epitope sequences bound with IG/TR. The CIG-DB is equipped with search engines for amino acid sequences and MEDLINE references, sequence analysis tools, and a 3D viewer. This database is accessible without charge or registration at http://www.scchr-cigdb.jp/, and the search results are freely downloadable. Conclusions The CIG-DB serves as a bridge between immunological gene data and cancer studies, presenting

  15. Microstructural evolution of all-wet-processed CIGS films using Raman spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hee Soo; Choi, Eunmi; Kim, Areum; Pyo, Sung Gyu [School of Integrative Engineering, Chung-Ang University, 221 Heukseok-Dong, Seoul, 156-756 (Korea, Republic of); Yoon, Sung Pil [Fuel Cell Research Center, Korea Institute of Science and Technology, Seoul, 136-791 (Korea, Republic of)

    2014-08-15

    We report a wet process deposition in order to identify a cost-effective processing scheme for CuIn{sub 1-x}Ga{sub x}Se{sub 2} (CIGS) layers on molybdenum/soda lime glass substrates from a Cu-In-Ga precursor solution. We employed a spin coater at various settings to evaluate the uniformity of the resulting CIGS solar cell layer. After the CIGS precursor film was deposited, we applied a selenization process. In the selenization process, we used a controlled temperature RTA system and compared it to a noncontrolled temperature system. We investigated the morphological properties for different selenization temperature treatments. We used Raman mapping to detect binary compounds and found the binary compound effect on the film. Raman mapping results show that the density of the binary compound in the CIGS layer increased with selenization temperature, and at 600 C, the density of the binary compounds was highest. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Degradation of CIGS solar cells due to the migration of alkali-elements

    NARCIS (Netherlands)

    Theelen, M.; Barreau, N.; Hans, V.; Steijvers, H.; Vroon, Z.; Zeman, M.

    2015-01-01

    Non-encapsulated CIGS solar cells with different contents of sodium (Na) and potassium (K) were simultaneously exposed to damp heat and illumination. The solar cells with higher alkali (Na, K) content exhibited higher initial conversion efficiencies, but degraded severely within 100 hours, while sam

  17. Designing novel thin film polycrystalline solar cells for high efficiency: sandwich CIGS and heterojunction perovskite

    Science.gov (United States)

    Wang, Tianyue; Chen, Jiewei; Wu, Gaoxiang; Song, Dandan; Li, Meicheng

    2017-01-01

    Heterojunction and sandwich architectures are two new-type structures with great potential for solar cells. Specifically, the heterojunction structure possesses the advantages of efficient charge separation but suffers from band offset and large interface recombination; the sandwich configuration is favorable for transferring carriers but requires complex fabrication process. Here, we have designed two thin-film polycrystalline solar cells with novel structures: sandwich CIGS and heterojunction perovskite, referring to the advantages of the architectures of sandwich perovskite (standard) and heterojunction CIGS (standard) solar cells, respectively. A reliable simulation software wxAMPS is used to investigate their inherent characteristics with variation of the thickness and doping density of absorber layer. The results reveal that sandwich CIGS solar cell is able to exhibit an optimized efficiency of 20.7%, which is much higher than the standard heterojunction CIGS structure (18.48%). The heterojunction perovskite solar cell can be more efficient employing thick and doped perovskite films (16.9%) than these typically utilizing thin and weak-doping/intrinsic perovskite films (9.6%). This concept of structure modulation proves to be useful and can be applicable for other solar cells. Project supported by the National High-Tech R&D Program of China (No. 2015AA034601), the National Natural Science Foundation of China (Nos. 91333122, 61204064, 51202067, 51372082, 51402106, 11504107), the Ph.D. Programs Foundation of Ministry of Education of China (Nos. 20120036120006, 20130036110012), the Par-Eu Scholars Program, and the Fundamental Research Funds for the Central Universities.

  18. The impact of atmospheric species on the degradation of CIGS solar cells

    NARCIS (Netherlands)

    Theelen, M.; Foster, C.; Steijvers, H.; Barreau, N.; Vroon, Z.; Zeman, M.

    2015-01-01

    CIGS solar cells were exposed to liquid water purged with the atmospheric gases carbon dioxide (CO2), oxygen (O2), nitrogen (N2) and air in order to investigate their chemical degradation behavior. The samples were analyzed by electrical, compositional and optical me

  19. The impact of selenisation on damp heat degradation of the CIGS back contact molybdenum

    NARCIS (Netherlands)

    Theelen, M.; Tomassini, M.; Barreau, N.; Steijvers, H.; Branca, A.; Harel, S.; Vroon, Z.; Zeman, M.

    2012-01-01

    Molybdenum (Mo) degrades under the influence of damp heat, thereby reducing the output of CIGS PV. In this study, Mo layers were deposited on a glass substrate by magnetron sputtering, thereby varying the deposition pressure and the addition of selenium. These samples were thoroughly analysed and de

  20. Thin film CIGS photovoltaic modules: monolithic integration and advanced packaging for high performance, high reliability and low cost

    Science.gov (United States)

    Eldada, Louay

    2011-01-01

    In recent years, thin-film photovoltaic companies started realizing their low manufacturing cost potential, and have been grabbing an increasingly larger market share. Copper Indium Gallium Selenide (CIGS) is the most promising thin-film PV material, having demonstrated the highest energy conversion efficiency in both cells and modules. However, most CIGS manufacturers still face the challenge of delivering a reliable and rapid manufacturing process that can scale effectively and deliver on the promise of this material system. HelioVolt has developed a reactive transfer process for CIGS absorber formation that has the benefits of good compositional control, and a fast high-quality CIGS reaction. The reactive transfer process is a two stage CIGS fabrication method. Precursor films are deposited onto substrates and reusable cover plates in the first stage, while in the second stage the CIGS layer is formed by rapid heating with Se confinement. HelioVolt also developed best-in-class packaging technologies that provide unparalleled environmental stability. High quality CIGS films with large grains were fabricated on the production line, and high-performance highreliability monolithic modules with a form factor of 120 cm × 60 cm are being produced at high yield and low cost. With conversion efficiency levels around 14% for cells and 12% for modules, HelioVolt is commercializing the process on its first production line with 20 MW capacity, and is planning its next GW-scale factory.

  1. Characteristics of CIGS photovoltaic devices co-evaporated with various Se flux rates at low temperatures

    Science.gov (United States)

    Huang, Chia-Hua; Lin, Chun-Ping; Jan, Yueh-Lin

    2016-08-01

    Cu(In,Ga)Se2 (CIGS) films were prepared by a single-stage co-evaporation process at Se flux rates of 10 Å s-1, 20 Å s-1, and 30 Å s-1 and substrate temperatures ranging from 400 °C to 500 °C. The flux rates of the Cu, In, Ga, and Se were kept constant throughout each deposition of the films. The grain sizes, surface morphologies, and crystallinity of the CIGS films improved with increasing substrate temperatures or Se flux rates. The causes of the formation of voids on the surface of CIGS films deposited with a low Se flux rate of 10 Å s-1 at substrate temperatures of 475 °C and 500 °C were addressed. The higher Se flux rates of 20 Å s-1 and 30 Å s-1 repressed the formation of voids for the CIGS films deposited at the relatively higher substrate temperatures of 475 °C and 500 °C. The conversion efficiencies of CIGS solar cells were significantly improved by increasing the substrate temperatures or the Se flux rates, largely contributed from the enhancement of the open-circuit voltage and fill factor because of the restraint of the carrier recombination. The short-circuit current densities were slightly enhanced by the increment of the substrate temperatures or the Se flux rates, resulting from the improved crystalline quality of the CIGS films. Moreover, the EQE results suggest that the effective carrier-diffusion lengths of the films deposited at the relatively high substrate temperatures were increased, leading to the enhancement of the short-circuit current density. The efficiencies of CIGS solar cells prepared with a Se flux rate of 10 Å s-1 improved from 10% to 12.4% when the substrate temperatures increased from 400 °C to 500 °C. The efficiencies of cells deposited at the substrate temperature of 500 °C improved to 15.4% as the Se flux rates increased from 10 Å s-1 to 30 Å s-1.

  2. Alternative Window Schemes for CuInSe2-Based Solar Cells Final Report: 3 November 1995-December 1997

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, L.C. (Electronic Materials Laboratory: Washington State University at Tri-Cities)

    1998-10-26

    This work demonstrated high-efficiency CIGS cells based on highly resistive ZnO buffer layers grown by MOCVD. One cell based on NREL CIGS and a ZnO buffer layer exhibited an active-area efficiency of nearly 14%. This result is one of the best efficiencies reported for a ''direct'' ZnO/CIGS cell made with a vacuum process.

  3. Evidence of p- to n-type inversion at CIGS grain boundaries: A depth-dependent surface electron microscopy study

    Science.gov (United States)

    Chan, Calvin; Ohta, Taisuke; Kellogg, Gary; Mansfield, Lorelle; Noufi, Rommel

    2014-03-01

    Chalcopyrite Cu(In1-xGax)Se2 (CIGS) is an interesting photovoltaic material because it holds the laboratory record for thin-film solar power conversion efficiency (η > 20 %) despite its disordered microcrystalline structure. However, commercialization of this technology has been limited by structural and chemical variations in CIGS films. Many microscopic and spectroscopic studies have shown built-in electric potentials (Φbi) at CIGS grain boundaries. This may assist with electron-hole separation, but the reported magnitude and statistical distribution of Φbi remains inconsistent between studies. In this work, photoemission and low-energy electron microscopies (PEEM and LEEM) were used to reconcile these reported differences. Highly surface sensitive PEEM measurements showed Φbi ~ 0 . 5 V, which was consistent with most other reports. However, more bulk sensitive LEEM measurements showed Φbi ~ 1 . 5 V, which strongly suggests p- to n-type inversion at CIGS grain boundaries. This formation of pn junctions at CIGS grain boundaries is likely responsible for the high performance of CIGS photovoltaics. Sandia is managed by Sandia Corp., a subsidiary of Lockheed Martin, for the U.S. DOE NNSA (DE-AC04-94AL85000). Work was supported by an U.S. DOE EERE SunShot Bridging Research Interactions through collaborative Development Grants in Energy (BRIDGE).

  4. Control over the preferred orientation of CIGS films deposited by magnetron sputtering using a wetting layer

    Science.gov (United States)

    Yan, Yong; Jiang, Fan; Liu, Lian; Yu, Zhou; Zhang, Yong; Zhao, Yong

    2016-01-01

    A growth method is presented to control the preferred orientation in chalcopyrite CuIn x Ga1- x Se2 (CIGS) thin films grown by magnetron sputtering. Films with (220/204) and (112) preferred orientation as well as randomly oriented films were prepared. The effects of an In2Se3 wetting layer and the working pressure on the texture transition phenomena were examined. A large-grained CIGS film with (220/204) texture was formed at 400°C with the inclusion of a thin (80 nm) In2Se3 layer and liquid phase (excess copper selenide phase) formation, and the reaction mechanism is proposed. The device deposited at 2.0 Pa on an In2Se3 layer exhibited the optimal electrical properties. [Figure not available: see fulltext.

  5. Chemistry in isolation: High CCH/HCO+ line ratio in the AMIGA galaxy CIG 638

    CERN Document Server

    Martin, S; Aladro, R; Espada, D; Argudo-Fernandez, M; Kramer, C; Scott, T C

    2014-01-01

    Multi-molecule observations towards an increasing variety of galaxies have been showing that the relative molecular abundances are affected by the type of activity. However, these studies are biased towards bright active galaxies, which are typically in interaction. We study the molecular composition of one of the most isolated galaxies in the local Universe where the physical and chemical properties of their molecular clouds have been determined by intrinsic mechanisms. We present 3 mm broad band observations of the galaxy CIG 638, extracted from the AMIGA sample of isolated galaxies. The emission of the J=1-0 transitions of CCH, HCN, HCO+, and HNC are detected. Integrated intensity ratios between these line are compared with similar observations from the literature towards active galaxies including starburst galaxies (SB), active galactic nuclei (AGN), luminous infrared galaxies (LIRG), and GMCs in M33. A significantly high ratio of CCH with respect to HCN, HCO+, and HNC is found towards CIG 638 when compar...

  6. Improving Efficiency of Multicrystalline Silicon and CIGS Solar Cells by Incorporating Metal Nanoparticles

    OpenAIRE

    Ming-Jer Jeng; Zih-Yang Chen; Yu-Ling Xiao; Liann-Be Chang; Jianping Ao; Yun Sun; Ewa Popko; Witold Jacak; Lee Chow

    2015-01-01

    This work studies the use of gold (Au) and silver (Ag) nanoparticles in multicrystalline silicon (mc-Si) and copper-indium-gallium-diselenide (CIGS) solar cells. Au and Ag nanoparticles are deposited by spin-coating method, which is a simple and low cost process. The random distribution of nanoparticles by spin coating broadens the resonance wavelength of the transmittance. This broadening favors solar cell applications. Metal shadowing competes with light scattering in a manner that varies w...

  7. Fabrication of CIGS thin films by using spray pyrolysis and post-selenization

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seong Yeon; Kim, Jun Ho [University of Incheon, Incheon (Korea, Republic of)

    2012-06-15

    We fabricated Cu(In{sub 1-x}Ga{sub x})Se{sub 2} (x: 0 ∼ 0.4) thin films by using ultrasonic spray pyrolysis and post-selenization. First, we made Cu(In{sub 1-x}Ga{sub x})S{sub 2} (x: 0 ∼ 0.4) films by ultrasonic spray pyrolysis under an air environment. Then, we converted as-sprayed Cu(In{sub 1-x}Ga{sub x})S{sub 2} (CIGS) films to Cu(In{sub 1-x}Ga{sub x})Se{sub 2} (CIGSe) films through post-selenization. For all Ga fractions, the sprayed CIGS films were well recrystallized into poly-crystalline CIGSe films with a dominant (112) texture, which was confirmed by X-ray diffraction, Raman spectroscopy and energy dispersive X-ray analyses. This result indicates that CIGSe films with any amount of Ga substitution can be made by converting sprayed CIGS to CIGSe with post-selenization.

  8. Improving Efficiency of Multicrystalline Silicon and CIGS Solar Cells by Incorporating Metal Nanoparticles

    Directory of Open Access Journals (Sweden)

    Ming-Jer Jeng

    2015-10-01

    Full Text Available This work studies the use of gold (Au and silver (Ag nanoparticles in multicrystalline silicon (mc-Si and copper-indium-gallium-diselenide (CIGS solar cells. Au and Ag nanoparticles are deposited by spin-coating method, which is a simple and low cost process. The random distribution of nanoparticles by spin coating broadens the resonance wavelength of the transmittance. This broadening favors solar cell applications. Metal shadowing competes with light scattering in a manner that varies with nanoparticle concentration. Experimental results reveal that the mc-Si solar cells that incorporate Au nanoparticles outperform those with Ag nanoparticles. The incorporation of suitable concentration of Au and Ag nanoparticles into mc-Si solar cells increases their efficiency enhancement by 5.6% and 4.8%, respectively. Incorporating Au and Ag nanoparticles into CIGS solar cells improve their efficiency enhancement by 1.2% and 1.4%, respectively. The enhancement of the photocurrent in mc-Si solar cells is lower than that in CIGS solar cells, owing to their different light scattering behaviors and material absorption coefficients.

  9. Improving the efficiency of copper indium gallium (Di-selenide (CIGS solar cells through integration of a moth-eye textured resist with a refractive index similar to aluminum doped zinc oxide

    Directory of Open Access Journals (Sweden)

    M. Burghoorn

    2014-12-01

    Full Text Available Textured transparent conductors are widely used in thin-film silicon solar cells. They lower the reflectivity at interfaces between different layers in the cell and/or cause an increase in the path length of photons in the Si absorber layer, which both result in an increase in the number of absorbed photons and, consequently, an increase in short-circuit current density (Jsc and cell efficiency. Through optical simulations, we recently obtained strong indications that texturing of the transparent conductor in copper indium gallium (di-selenide (CIGS solar cells is also optically advantageous. Here, we experimentally demonstrate that the Jsc and efficiency of CIGS solar cells with an absorber layer thickness (dCIGS of 0.85 μm, 1.00 μm and 2.00 μm increase through application of a moth-eye textured resist with a refractive index that is sufficiently similar to AZO (nresist = 1.792 vs. nAZO = 1.913 at 633 nm to avoid large optical losses at the resist-AZO interface. On average, Jsc increases by 7.2%, which matches the average reduction in reflection of 7.0%. The average relative increase in efficiency is slightly lower (6.0%. No trend towards a larger relative increase in Jsc with decreasing dCIGS was observed. Ergo, the increase in Jsc can be fully explained by the reduction in reflection, and we did not observe any increase in Jsc based on an increased photon path length.

  10. Improving the efficiency of copper indium gallium (Di-)selenide (CIGS) solar cells through integration of a moth-eye textured resist with a refractive index similar to aluminum doped zinc oxide

    Energy Technology Data Exchange (ETDEWEB)

    Burghoorn, M.; Kniknie, B.; Deelen, J. van; Ee, R. van [The Netherlands Organisation for Applied Scientific Research (TNO), De Rondom 1, 5612 AP, Eindhoven (Netherlands); Xu, M. [The Netherlands Organisation for Applied Scientific Research (TNO), De Rondom 1, 5612 AP, Eindhoven (Netherlands); Delft University of Technology, Optics Group, Van der Waalsweg 8, 2628 CH, Delft (Netherlands); Vroon, Z. [The Netherlands Organisation for Applied Scientific Research (TNO), De Rondom 1, 5612 AP, Eindhoven (Netherlands); Zuyd Hogeschool, Nieuw Eyckholt 300, 6419 DJ, Heerlen (Netherlands); Belt, R. van de [Kriya Materials BV, Urmonderbaan 22, 6167 RD, Geleen (Netherlands); Buskens, P., E-mail: pascal.buskens@tno.nl, E-mail: buskens@dwi.rwth-aachen.de [The Netherlands Organisation for Applied Scientific Research (TNO), De Rondom 1, 5612 AP, Eindhoven (Netherlands); DWI – Leibniz Institute for Interactive Materials, Forckenbeckstrasse 50, 52056, Aachen (Germany)

    2014-12-15

    Textured transparent conductors are widely used in thin-film silicon solar cells. They lower the reflectivity at interfaces between different layers in the cell and/or cause an increase in the path length of photons in the Si absorber layer, which both result in an increase in the number of absorbed photons and, consequently, an increase in short-circuit current density (J{sub sc}) and cell efficiency. Through optical simulations, we recently obtained strong indications that texturing of the transparent conductor in copper indium gallium (di-)selenide (CIGS) solar cells is also optically advantageous. Here, we experimentally demonstrate that the J{sub sc} and efficiency of CIGS solar cells with an absorber layer thickness (d{sub CIGS}) of 0.85 μm, 1.00 μm and 2.00 μm increase through application of a moth-eye textured resist with a refractive index that is sufficiently similar to AZO (n{sub resist} = 1.792 vs. n{sub AZO} = 1.913 at 633 nm) to avoid large optical losses at the resist-AZO interface. On average, J{sub sc} increases by 7.2%, which matches the average reduction in reflection of 7.0%. The average relative increase in efficiency is slightly lower (6.0%). No trend towards a larger relative increase in J{sub sc} with decreasing d{sub CIGS} was observed. Ergo, the increase in J{sub sc} can be fully explained by the reduction in reflection, and we did not observe any increase in J{sub sc} based on an increased photon path length.

  11. Improving the efficiency of copper indium gallium (Di-)selenide (CIGS) solar cells through integration of a moth-eye textured resist with a refractive index similar to aluminum doped zinc oxide

    Science.gov (United States)

    Burghoorn, M.; Kniknie, B.; van Deelen, J.; Xu, M.; Vroon, Z.; van Ee, R.; van de Belt, R.; Buskens, P.

    2014-12-01

    Textured transparent conductors are widely used in thin-film silicon solar cells. They lower the reflectivity at interfaces between different layers in the cell and/or cause an increase in the path length of photons in the Si absorber layer, which both result in an increase in the number of absorbed photons and, consequently, an increase in short-circuit current density (Jsc) and cell efficiency. Through optical simulations, we recently obtained strong indications that texturing of the transparent conductor in copper indium gallium (di-)selenide (CIGS) solar cells is also optically advantageous. Here, we experimentally demonstrate that the Jsc and efficiency of CIGS solar cells with an absorber layer thickness (dCIGS) of 0.85 μm, 1.00 μm and 2.00 μm increase through application of a moth-eye textured resist with a refractive index that is sufficiently similar to AZO (nresist = 1.792 vs. nAZO = 1.913 at 633 nm) to avoid large optical losses at the resist-AZO interface. On average, Jsc increases by 7.2%, which matches the average reduction in reflection of 7.0%. The average relative increase in efficiency is slightly lower (6.0%). No trend towards a larger relative increase in Jsc with decreasing dCIGS was observed. Ergo, the increase in Jsc can be fully explained by the reduction in reflection, and we did not observe any increase in Jsc based on an increased photon path length.

  12. Ecotoxicological assessment of solar cell leachates: Copper indium gallium selenide (CIGS) cells show higher activity than organic photovoltaic (OPV) cells

    Energy Technology Data Exchange (ETDEWEB)

    Brun, Nadja Rebecca [University of Applied Sciences and Arts Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH-4132 Muttenz (Switzerland); Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, Universitätsstrasse 16, CH-8092 Zürich (Switzerland); Wehrli, Bernhard [Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, Universitätsstrasse 16, CH-8092 Zürich (Switzerland); Fent, Karl, E-mail: karl.fent@fhnw.ch [University of Applied Sciences and Arts Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH-4132 Muttenz (Switzerland); Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, Universitätsstrasse 16, CH-8092 Zürich (Switzerland)

    2016-02-01

    Despite the increasing use of photovoltaics their potential environmental risks are poorly understood. Here, we compared ecotoxicological effects of two thin-film photovoltaics: established copper indium gallium selenide (CIGS) and organic photovoltaic (OPV) cells. Leachates were produced by exposing photovoltaics to UV light, physical damage, and exposure to environmentally relevant model waters, representing mesotrophic lake water, acidic rain, and seawater. CIGS cell leachates contained 583 μg L{sup −1} molybdenum at lake water, whereas at acidic rain and seawater conditions, iron, copper, zinc, molybdenum, cadmium, silver, and tin were present up to 7219 μg L{sup −1}. From OPV, copper (14 μg L{sup −1}), zinc (87 μg L{sup −1}) and silver (78 μg L{sup −1}) leached. Zebrafish embryos were exposed until 120 h post-fertilization to these extracts. CIGS leachates produced under acidic rain, as well as CIGS and OPV leachates produced under seawater conditions resulted in a marked hatching delay and increase in heart edema. Depending on model water and solar cell, transcriptional alterations occurred in genes involved in oxidative stress (cat), hormonal activity (vtg1, ar), metallothionein (mt2), ER stress (bip, chop), and apoptosis (casp9). The effects were dependent on the concentrations of cationic metals in leachates. Addition of ethylenediaminetetraacetic acid protected zebrafish embryos from morphological and molecular effects. Our study suggests that metals leaching from damaged CIGS cells, may pose a potential environmental risk. - Highlights: • Photovoltaics may be disposed in the environment after usage. • Copper indium gallium selenide (CIGS) and organic (OPV) cells were compared. • Morphological and molecular effects were assessed in zebrafish embryos. • Environmental condition affected metal leaching and ecotoxicological activity. • Damaged CIGS cells pose higher risk to the environment than OPV cells.

  13. Comparison on cellular mechanisms of iron and cadmium accumulation in rice: prospects for cultivating Fe-rich but Cd-free rice.

    Science.gov (United States)

    Gao, Lei; Chang, Jiadong; Chen, Ruijie; Li, Hubo; Lu, Hongfei; Tao, Longxing; Xiong, Jie

    2016-12-01

    Iron (Fe) is essential for rice growth and humans consuming as their staple food but is often deficient because of insoluble Fe(III) in soil for rice growth and limited assimilation for human bodies, while cadmium (Cd) is non-essential and toxic for rice growth and humans if accumulating at high levels. Over-accumulated Cd can cause damage to human bodies. Selecting and breeding Fe-rich but Cd-free rice cultivars are ambitious, challenging and meaningful tasks for researchers. Although evidences show that the mechanisms of Fe/Cd uptake and accumulation in rice are common to some extent as a result of similar entry routes within rice, an increasing number of researchers have discovered distinct mechanisms between Fe/Cd uptake and accumulation in rice. This comprehensive review systematically elaborates and compares cellular mechanisms of Fe/Cd uptake and accumulation in rice, respectively. Mechanisms for maintaining Fe homeostasis and Cd detoxicification are also elucidated. Then, effects of different fertilizer management on Fe/Cd accumulation in rice are discussed. Finally, this review enumerates various approaches for reducing grain Cd accumulation and enhancing Fe content in rice. In summary, understanding of discrepant cellular mechanisms of Fe/Cd accumulation in rice provides guidance for cultivating Fe-fortified rice and has paved the way to develop rice that are tolerant to Cd stress, aiming at breeding Fe-rich but Cd-free rice.

  14. Ecotoxicological assessment of solar cell leachates: Copper indium gallium selenide (CIGS) cells show higher activity than organic photovoltaic (OPV) cells.

    Science.gov (United States)

    Brun, Nadja Rebecca; Wehrli, Bernhard; Fent, Karl

    2016-02-01

    Despite the increasing use of photovoltaics their potential environmental risks are poorly understood. Here, we compared ecotoxicological effects of two thin-film photovoltaics: established copper indium gallium selenide (CIGS) and organic photovoltaic (OPV) cells. Leachates were produced by exposing photovoltaics to UV light, physical damage, and exposure to environmentally relevant model waters, representing mesotrophic lake water, acidic rain, and seawater. CIGS cell leachates contained 583 μg L(-1) molybdenum at lake water, whereas at acidic rain and seawater conditions, iron, copper, zinc, molybdenum, cadmium, silver, and tin were present up to 7219 μg L(-1). From OPV, copper (14 μg L(-1)), zinc (87 μg L(-1)) and silver (78 μg L(-1)) leached. Zebrafish embryos were exposed until 120 h post-fertilization to these extracts. CIGS leachates produced under acidic rain, as well as CIGS and OPV leachates produced under seawater conditions resulted in a marked hatching delay and increase in heart edema. Depending on model water and solar cell, transcriptional alterations occurred in genes involved in oxidative stress (cat), hormonal activity (vtg1, ar), metallothionein (mt2), ER stress (bip, chop), and apoptosis (casp9). The effects were dependent on the concentrations of cationic metals in leachates. Addition of ethylenediaminetetraacetic acid protected zebrafish embryos from morphological and molecular effects. Our study suggests that metals leaching from damaged CIGS cells, may pose a potential environmental risk.

  15. Simulation of the Efficiency of CdS/CIGS Tandem Multi-Junction Solar Cells Using AMPS-1D

    CERN Document Server

    Mirkamali, Ashrafalsadat S

    2016-01-01

    In this paper we conduct numerical simulation of CdS/CIGS solar cells by use of the AMPS-1D software aiming to formulate the optimal design of the new multi-junction tandem solar cell providing its most efficient operation. We start with the numerical simulation of single-junction CdS/CIGS solar cells, which shows that its highest efficiency of 17.3% could be achieved by the thickness of CIGS p-layer of 200 nm. This result is in a good agreement with experimental data where the highest efficiency was 17.1% with the solar cell thickness of 1 micron. By use of the results of the numerical simulation of the single-junction solar cells we developed the design and conducted optimization of the new multi-junction tandem CdS/CIGS solar cell structure. Numerical simulation shows that the maximum efficiency of this solar cell is equal to 48.3%, which could be obtained with the thickness of the CIGS p-layer of 600 nm at a standard illumination of AM 1.5.

  16. Matemáticas y literatura de 0 a 3: Un cuento de cigüeñas

    Directory of Open Access Journals (Sweden)

    Gonzalo Flecha López

    2014-12-01

    Full Text Available A partir de los elementos del entorno próximo, tanto físico como cultural, podemos abordar conceptos matemáticos relacionados con la clasificación y con la formación de conjuntos. Utilizando como punto de partida los cuentos “El libro del otoño” y “Un cuento de cigüeñas”, vamos a tratar de realizar clasificaciones utilizando como base la formación de conceptos. Realizaremos, con los niños, agrupamientos sencillos mediante relaciones equivalencia. Mathematics and literature from zero to three: A tale of storks. From the elements of the surrounding environment both physical and cultural, we can deal with mathematical concepts related to classification and formation of sets. Using as a starting point the reading of “The book of autumn” and “A tale of storks”, we will try to make classifications using as base concept formation. We will make, with children, simple groupings using equivalence relations.

  17. The Effect of Sputtering Parameters on the Film Properties of Molybdenum Back Contact for CIGS Solar Cells

    Directory of Open Access Journals (Sweden)

    Peng-cheng Huang

    2013-01-01

    Full Text Available Molybdenum (Mo thin films are widely used as a back contact for CIGS-based solar cells. This paper determines the optimal settings for the sputtering parameters for an Mo thin film prepared on soda lime glass substrates, using direct current (dc magnetron sputtering, with a metal Mo target, in an argon gas environment. A Taguchi method with an L9 orthogonal array, the signal-to-noise ratio, and an analysis of variances is used to determine the performance characteristics of the coating operation. The main sputtering parameters, such as working pressure (mTorr, dc power (W, and substrate temperature (°C, are optimized with respect to the structural features, surface morphology, and electrical properties of the Mo films. An adhesive tape test is performed on each film to determine the adhesion strength of the films. The experimental results show that the working pressure has the dominant effect on electrical resistivity and reflectance. The intensity of the main peak (110 for the Mo film increases and the full width at half maximum decreases gradually as the sputtering power is increased. Additionally, the application of an Mo bilayer demonstrates good adherence and low resistivity.

  18. CIGS P3 scribes using ultra-short laser pulses and thermal annealing

    Science.gov (United States)

    Matthäus, Gabor; Bergner, Klaus; Ametowobla, Mawuli A.; Letsch, Andreas; Tünnermann, Andreas; Nolte, Stefan

    2016-03-01

    Thin-film photovoltaic panels consist of individual solar cells which are monolithically interconnected in series. Today, these connections are commonly realized by mechanical methods. In order to increase the solar output, it is one approach to minimize the interconnection area (so called "dead area"). In this regard, recent advances in laser patterning are gaining increasing potential. However, especially high-impedance trenches realized via laser scribing generally suffer from insufficient shunt resistances. This is especially the case for the third structuring stage P3 of CIGS solar modules, which represents the isolation of nearby cells.

  19. Recent Progress in CIGS Thin Film Solar Cell Research at NREL: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Ramanathan, K.; Hasoon, F. S.; Al-Thani, H.; Alleman, J.; Keane, J.; Dolan, J.; Contreras, M. A.; Bhattacharya, R.; Noufi, R.

    2001-10-01

    Presented at the 2001 NCPV Program Review Meeting: This paper summarizes our work toward improving reproducibility in fabricating high efficiency absorbers and devices. This paper summarizes our work toward improving reproducibility in fabricating high efficiency absorbers and devices. This resulted in the fabrication of a CIGS cell with an efficiency of 21% under concentrated light. We compare devices fabricated with CdS and with Cd solution treatment alone. A high conversion efficiency of 15.7% is obtained with the latter, and we attribute this to the n-type doping afforded by Cd. The work is extended to absorbers provided by Siemens Solar Industries (SSI).

  20. Fabrication of high color rendering index white LED using Cd-free wavelength tunable Zn doped CuInS2 nanocrystals.

    Science.gov (United States)

    Chung, Wonkeun; Jung, Hyunchul; Lee, Chang Hun; Kim, Sung Hyun

    2012-10-22

    Highly luminescent Cd-free Zn doped CuInS(2) nanocrystals (ZCIS NCs) were synthesized, and their properties were evaluated using X-ray diffraction, Raman, UV, and photoluminescence. The crystal structure of the ZCIS NCs was similar to the zinc blende, and the lattice constant decreased with increasing Zn concentration. By incorporation of Zn, the emission wavelength was tuned from 536 to 637 nm with concomitant enhancement of the quantum yield up to 45%. A white light emitting diodes, integrating dual ZCIS NCs (λ(em) = 567, and 617 nm) and a 460 nm InGaN LED, exhibited a high color rendering index of 84.1 with a warm color temperature of 4256.2K. The CIE-1931 chromaticity coordinates were slightly shifted from (0.3626, 0.3378) at 20 mA to (0.3480, 0.3206) at 50 mA.

  1. Properties of Encapsulated CIGS Cells in 85 degrees C/85%RH

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, Larry C.; Gross, Mark E.; Kundu, Sambhu N.; Shafaman, William N.

    2010-02-16

    This paper concerns studies of encapsulated cells subjected to an environment of 85ºC and 85%RH (85/85). Cells are encapsulated with PNNL multi-layer coatings (referred to as PML coatings) utilizing alternating layers of Al2O3, and an advanced polymer. The new polymer has been determined to withstand the 85/85 environment. Two types of cells were used for these studies, namely, SSI mini-modules (which are actually CIGSS devices) and CIGS cells provided by the Institute of Energy Conversion (IEC). Cells were coated and stressed at 85/85 in an environmental chamber. Current-voltage characteristics were acquired before and after coating, and periodically after being subjected to the 85/85 environment. Whereas coated SSI modules were determined to last 1000 hours when stressed at 60ºC/90%RH without degradation, the efficiency of these modules degrade to a level of 60% of the beginning-of-life value when stressed at 85/85. Encapsulated IEC cells, however, have exhibited extraordinary results. The efficiency of several encapsulated cells did not decrease for 1500 hours in an 85ºC/85%RH environment. This results establishes a benchmark for stressed, encapsulated CIGS cells.

  2. Aspects of designing an optimized molybdenum back contact in CIGS-technology

    Energy Technology Data Exchange (ETDEWEB)

    Oertel, Michael; Goetz, Stefan; Haarstrich, Jakob; Metzner, Heinrich; Reisloehner, Udo; Ronning, Carsten; Wesch, Werner [Institut fuer Festkoerperphysik, Friedrich-Schiller-Universitaet Jena, 07743 Jena (Germany)

    2011-07-01

    In Cu(In,Ga)Se{sub 2}(CIGS)-solar cell and module production, the sputtering of the molybdenum back contact is the first step in nearly all process lines. We present our results of experiments to elucidate the different aspects which have to be kept in mind when depositing the molybdenum back contact by dc-magnetron sputtering. These aspects include: I) The adhesion of the molybdenum to the glass substrate as well as the adhesion of the CIGS-layer to the molybdenum, II) electrical conductivity, III) sodium diffusion and IV) the specific contact resistance of the molybdenum to the aluminium doped zinc oxide (Al:ZnO) window layer. We present our three layer design of the back contact which combines an optimized adhesion to both the substrate and the absorber and also a high electrical conductivity. X-ray diffraction measurements (XRD) are employed to characterize each single layer. We also discuss I-U-measurements of CuInSe{sub 2}-solar cells made in a sequential absorber layer process in order to study the sodium transport behaviour of molybdenum back contacts sputtered at different argon sputter pressures. The sodium content in the absorber and the different back contact layers is measured by secondary ion mass spectroscopy (SIMS). A lowest value of the specific contact resistance between the Mo and the Al:ZnO of (1.37{+-}0.14).10{sup 5} {omega}cm{sup 2} was determined.

  3. Impact of P2 scribe geometry on monolithic series interconnected CIGS modules

    Science.gov (United States)

    Rekow, M.; Bartl, D.; Sandfort, C.; Letsch, A.

    2013-03-01

    The CIGS (Copper Indium Gallium Selenide) solar panel industry is cautiously moving to adopt laser processes for the P2 and the P3 scribe steps that form the electrical interconnection between cells within a module [1]. In this work we study variants of these two laser processes and evaluate their relative performance. P2 scribes are applied with geometries that range from continuous scribes to discrete spots and we examine the relationship between scribe geometry and P2 contact resistance. Transmission line theory [2] is used to calculate P2 contact resistance as is common in the industry. The results are compared with two simple geometric models that predict relative contact resistance for different scribe geometries. We also apply different types of scribes for both P2 and P3 in the production of minimodules and evaluate the results. We find that not only is the optimal geometry for the P2 scribe a continuous line, high overlap of the laser spots yields an improvement in contact resistance not predicted by geometry alone. Finally we find that removing only the TCO (transparent conductive oxide) layer for the P3 scribe results in modules with good efficiency, however a P3 scribe that removes the TCO and CIGS layer yields better modules with about 1% higher absolute efficiency.

  4. Soft X-ray absorption spectroscopy investigation of the surface chemistry and treatments of copper indium gallium diselenide (CIGS)

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, Craig; Nordlund, Dennis; Sokaras, Dimosthenis; Contreras, Miguel; Weng, Tsu-Chien; Mansfield, Lorelle; Hurst, Katherine E.; Dameron, Arrelaine; Ramanathan, Kannan; Prendergast, David; Christensen, Steven T.

    2017-02-01

    The surface and near surface structure of copper-indium-gallium-selenide (CIGS) absorber layers is integral to the producing a high-quality photovoltaic junction. By using X-ray absorption spectroscopy (XAS) and monitoring multiple elemental absorption edges with both theory and experiment, we are able to identify several features of the surface of CIGS as a function of composition and surface treatments. The XAS data shows trends in the near surface region of oxygen, copper, indium and gallium species as the copper content is varied in the films. The oxygen surface species are also monitored through a series of experiments that systematically investigates the effects of water and various solutions of: ammonium hydroxide, cadmium sulfate, and thiourea. These being components of cadmium sulfide chemical bath deposition (CBD). Characteristics of the CBD are correlated with a restorative effect that produces as normalized, uniform surface chemistry as measured by XAS. This surface chemistry is found in CIGS solar cells with excellent power conversion efficiency (<19%). The results provide new insight for CIGS processing strategies that seek to replace CBD and/or cadmium sulfide.

  5. Nd:YAG laser annealing investigation of screen-printed CIGS layer on PET: Layer annealing method for photovoltaic cell fabrication process

    KAUST Repository

    Alsaggaf, Ahmed

    2014-06-01

    Cu(In, Ga)Se2 (CIGS) ink was formulated from CIGS powder, polyvinyl butyral PVB, terpineol and polyester/polyamine co-polymeric dispersant KD-1. Thin films with different thicknesses were deposited on PET substrate using screen-printing followed by heat treatment using a Nd:YAG laser. The structure and morphology of the heated thin films were studied. The characterization of the CIGS powder, ink, and film was done using TGA, SEM, FIB, EDS, and XRD. TGA analysis shows that the CIGS ink is drying at 200 °C, which is well below the decomposition temperature of the PET substrate. It was observed by SEM that 20 pulses of 532nm and 60 mJ/cm2 Nd:YAG laser annealing causes atomic diffusion on the near surface area. Furthermore, FIB cross section images were utilized to monitor the effect of laser annealing in the depth of the layer. Laser annealing effects were compared to as deposited layer using XRD in reference to CIGS powder. The measurement shows that crystallinity of deposited CIGS is retained while EDS quantification and atomic ratio result in gradual loss of selenium as laser energy increases. The laser parameters were tuned in an effort to utilize laser annealing of screen-printed CIGS layer as a layer annealing method for solar cell fabrication process.

  6. CIGS P1, P2, P3 Scribing Processes using a Pulse Programmable Industrial Fiber Laser: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Rekow, M.; Murison, R.; Panarello, T.; Dunsky, C.; Dinkel, C.; Nikumb, S.; Pern, F. J.; Mansfield, L.

    2010-10-01

    We describe a novel set of laser processes for the CIGS P1, P2 and P3 scribing steps, the development of which has been enabled by a unique pulse-programmable fiber laser. We find that the unique pulse control properties of this 1064 nm wavelength laser have significant effects on the material removal dynamics of the various film layers in the CIGS material system. In the case of the P2 and P3 processes, the shaped pulses create new laser/material interaction effects that permit the material to be cleanly and precisely removed with zero Heat Affected Zone (HAZ) at the edges of the scribe. The new P2 and P3 processes we describe demonstrate the first use of infrared nanosecond laser pulses that eliminate the HAZ and the consequent localized compositional changes in the CIGS absorber material that result in poor shunt resistance. SEM micrographs and EDX compositional scans are presented. For the P1 scribe, we process the bi-layer molybdenum from the film side as well as through the glass substrate. Microscopic inspection and compositional analysis of the scribe lines are not sufficient to determine electrical and optical performance in working PV modules. Therefore, to demonstrate the applicability of the infrared pulse-programmable laser to all three scribing processes for thin-film CIGS, we fabricate small-size multiple-cell monolithically interconnected mini-modules in partnership with the National Renewable Energy Laboratory (Golden, Colorado). A total of four mini-modules are produced, two utilizing all laser scribing, and two with the P2 and P3 steps mechanically scribed (by a third party) for reference. Mini-module performance data measured at NREL is presented, and we also discuss the commercialization potential of the new single-laser CIGS scribing process. Finally we present a phenomenological model to describe this physics underlying this novel ablation process.

  7. Semi-transparent perovskite solar cells for tandems with silicon and CIGS

    KAUST Repository

    Bailie, Colin D.

    2015-01-01

    © 2015 The Royal Society of Chemistry. A promising approach for upgrading the performance of an established low-bandgap solar technology without adding much cost is to deposit a high bandgap polycrystalline semiconductor on top to make a tandem solar cell. We use a transparent silver nanowire electrode on perovskite solar cells to achieve a semi-transparent device. We place the semi-transparent cell in a mechanically-stacked tandem configuration onto copper indium gallium diselenide (CIGS) and low-quality multicrystalline silicon (Si) to achieve solid-state polycrystalline tandem solar cells with a net improvement in efficiency over the bottom cell alone. This work paves the way for integrating perovskites into a low-cost and high-efficiency (>25%) tandem cell.

  8. Efficiency enhancement in two-cell CIGS photovoltaic system with low-cost optical spectral splitter.

    Science.gov (United States)

    Maragliano, Carlo; Apostoleris, Harry; Bronzoni, Matteo; Rampino, Stefano; Stefancich, Marco; Chiesa, Matteo

    2016-01-25

    Spectrum splitting represents a valid alternative to multi-junction solar cells for broadband light-to-electricity conversion. While this concept has existed for decades, its adoption at the industrial scale is still stifled by high manufacturing costs and inability to scale to large areas. Here we report the experimental validation of a novel design that could allow the widespread adoption of spectrum splitting as a low-cost approach to high efficiency photovoltaic conversion. Our system consists of a prismatic lens that can be manufactured using the same methods employed for conventional CPV optic production, and two inexpensive CuInGaSe(2) (CIGS) solar cells having different composition and, thus, band gaps. We demonstrate a large improvement in cell efficiency under the splitter and show how this can lead to substantial increases in system output at competitive cost using existing technologies.

  9. Uniform, High Efficiency, Hybrid CIGS Process with Application to Novel Device Structures: Annual Technical Report, 15 March 2005 - 14 March 2006

    Energy Technology Data Exchange (ETDEWEB)

    Delahoy, A. E.; Chen, L.; Sang, B.

    2006-06-01

    One of the main Phase I objectives of this subcontract was for EPV to demonstrate 14%-efficient CIGS devices using a hybrid process. The processing was also required to have good control ability. These goals were successfully accomplished. It will be seen that during Phase I, we successfully developed a new, simplified hybrid process. A highlight of intensive work was the achievement of a 14.0% NREL-verified device at a CIGS thickness of 1.13 ..mu..m. The simplified hybrid process considerably reduces CIGS film formation time and offers the promise of being a truly cost-effective and manufacturable one. It is considered to be one of the more attractive CIGS processes in the industry.

  10. Notas sobre Feral y las cigüeñas, de Fernando Alonso, y la "Historia del califa cigüeña" (Wilhelm Hauff, Sara Cone Bryant

    Directory of Open Access Journals (Sweden)

    Hans Christian Hagedorn

    2011-01-01

    Full Text Available En el presente estudio se analizan las fuentes de la versión de la "Historia del califa cigüeña", incluida en la narración Feral y las cigüeñas (1971, de Fernando Alonso. Para ello se tienen en cuenta el cuento original del autor postromántico alemán Wilhelm Hauff ("Die Geschichte von Kalif Storch", 1825, y la adaptación de este cuento que Sara Cone Bryant realizó para su libro How to tell stories to children (1905, traducción española: El arte de contar cuentos, 1965.

  11. Stability of CIGS Solar Cells and Component Materials Evaluated by a Step-Stress Accelerated Degradation Test Method: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Pern, F. J.; Noufi, R.

    2012-10-01

    A step-stress accelerated degradation testing (SSADT) method was employed for the first time to evaluate the stability of CuInGaSe2 (CIGS) solar cells and device component materials in four Al-framed test structures encapsulated with an edge sealant and three kinds of backsheet or moisture barrier film for moisture ingress control. The SSADT exposure used a 15oC and then a 15% relative humidity (RH) increment step, beginning from 40oC/40%RH (T/RH = 40/40) to 85oC/70%RH (85/70) as of the moment. The voluminous data acquired and processed as of total DH = 3956 h with 85/70 = 704 h produced the following results. The best CIGS solar cells in sample Set-1 with a moisture-permeable TPT backsheet showed essentially identical I-V degradation trend regardless of the Al-doped ZnO (AZO) layer thickness ranging from standard 0.12 μm to 0.50 μm on the cells. No clear 'stepwise' feature in the I-V parameter degradation curves corresponding to the SSADT T/RH/time profile was observed. Irregularity in I-V performance degradation pattern was observed with some cells showing early degradation at low T/RH < 55/55 and some showing large Voc, FF, and efficiency degradation due to increased series Rs (ohm-cm2) at T/RH ≥ 70/70. Results of (electrochemical) impedance spectroscopy (ECIS) analysis indicate degradation of the CIGS solar cells corresponded to increased series resistance Rs (ohm) and degraded parallel (minority carrier diffusion/recombination) resistance Rp, capacitance C, overall time constant Rp*C, and 'capacitor quality' factor (CPE-P), which were related to the cells? p-n junction properties. Heating at 85/70 appeared to benefit the CIGS solar cells as indicated by the largely recovered CPE-P factor. Device component materials, Mo on soda lime glass (Mo/SLG), bilayer ZnO (BZO), AlNi grid contact, and CdS/CIGS/Mo/SLG in test structures with TPT showed notable to significant degradation at T/RH ≥ 70/70. At T/RH = 85/70, substantial blistering of

  12. Stability of CIGS solar cells and component materials evaluated by a step-stress accelerated degradation test method

    Science.gov (United States)

    Pern, F. J.; Noufi, R.

    2012-10-01

    A step-stress accelerated degradation testing (SSADT) method was employed for the first time to evaluate the stability of CuInGaSe2 (CIGS) solar cells and device component materials in four Al-framed test structures encapsulated with an edge sealant and three kinds of backsheet or moisture barrier film for moisture ingress control. The SSADT exposure used a 15°C and then a 15% relative humidity (RH) increment step, beginning from 40°C/40%RH (T/RH = 40/40) to 85°C/70%RH (85/70) as of the moment. The voluminous data acquired and processed as of total DH = 3956 h with 85/70 = 704 h produced the following results. The best CIGS solar cells in sample Set-1 with a moisture-permeable TPT backsheet showed essentially identical I-V degradation trend regardless of the Al-doped ZnO (AZO) layer thickness ranging from standard 0.12 μm to 0.50 μm on the cells. No clear "stepwise" feature in the I-V parameter degradation curves corresponding to the SSADT T/RH/time profile was observed. Irregularity in I-V performance degradation pattern was observed with some cells showing early degradation at low T/RH = 70/70. Results of (electrochemical) impedance spectroscopy (ECIS) analysis indicate degradation of the CIGS solar cells corresponded to increased series resistance Rs (ohm) and degraded parallel (minority carrier diffusion/recombination) resistance Rp, capacitance C, overall time constant Rp*C, and "capacitor quality" factor (CPE-P), which were related to the cells' p-n junction properties. Heating at 85/70 appeared to benefit the CIGS solar cells as indicated by the largely recovered CPE-P factor. Device component materials, Mo on soda lime glass (Mo/SLG), bilayer ZnO (BZO), AlNi grid contact, and CdS/CIGS/Mo/SLG in test structures with TPT showed notable to significant degradation at T/RH >= 70/70. At T/RH = 85/70, substantial blistering of BZO layers on CIGS cell pieces was observed that was not seen on BZO/glass, and a CdS/CIGS sample displayed a small darkening and then

  13. Cd-free buffer layer materials on Cu2ZnSn(SxSe1-x)4: Band alignments with ZnO, ZnS, and In2S3

    Science.gov (United States)

    Barkhouse, D. Aaron R.; Haight, Richard; Sakai, Noriyuki; Hiroi, Homare; Sugimoto, Hiroki; Mitzi, David B.

    2012-05-01

    The heterojunctions formed between Cu2ZnSn(SxSe1-x)4 (CZTSSe) and three Cd-free n-type buffers, ZnS, ZnO, and In2S3, were studied using femtosecond ultraviolet photoemission and photovoltage spectroscopy. The electronic properties including the Fermi level location at the interface, band bending in the CZTSSe substrate, and valence and conduction band offsets were determined and correlated with device properties. We also describe a method for determining the band bending in the buffer layer and demonstrate this for the In2S3/CZTSSe system. The chemical bath deposited In2S3 buffer is found to have near optimal conduction band offset (0.15 eV), enabling the demonstration of Cd-free In2S3/CZTSSe solar cells with 7.6% power conversion efficiency.

  14. Study on the Distance Optimization Between Laser Scribing Lines in CIGS Solar Module%铜铟镓硒薄膜组件激光刻线最佳间距的研究

    Institute of Scientific and Technical Information of China (English)

    彭寿; 王丛笑; 杨卫明; 傅干华; 王伟; 吴美平

    2016-01-01

    通过建立数学模型推导出以有效工作区宽度w为参数的功率损失方程,根据铜铟镓硒薄膜和导电膜的实际电学参数计算出了优化的w值,从而得到最佳激光刻线间距为5.56 mm,进一步研究了铜铟镓硒薄膜组件激光刻线间距对输出功率损失的影响。%An active area width as w based power loss equation is deduced by setting up a mathematic model.Based on the real electrical parameters of CIGS and the transparent conductive oxide thin film,the optimized w is calculated, and the optimized distance of 5 .5 6 mm between laser scribing lines is also calculated.The impact of power loss due to the distance between laser scribing lines in CIGS module is investigated.

  15. Pulsed Laser Deposition ZnS Buffer Layers for CIGS Solar Cells

    Institute of Scientific and Technical Information of China (English)

    Pai-feng Luo; Guo-shun Jiang; Chang-fei Zhu

    2009-01-01

    Polycrystalline ZnS films were prepared by pulsed laser deposition (PLD) on quartz glass substrates under different growth conditions at different substrate temperatures of 20, 200, 400, and 600 ℃, which is a suitable alternative to chemical bath deposited (CBD) CdS as a buffer layer in Cu(In,Ga)Se2 (CIGS) solar cells. X-ray diffraction studies indicate the films are polycrystalline with zinc-blends structure and they exhibit preferential orientation along the cubic phase β-ZnS (111) direction, which conflicts with the conclusion of wurtzite struc-ture by Murali that the ZnS films deposited by pulse plating technique was polycrystalline with wurtzite structure. The Raman spectra of grown films show A1 mode at approxi-mately 350 cm-1, generally observed in the cubic phase β-ZnS compounds. The planar and the cross-sectional morphology were observed by scanning electron microscopic. The dense, smooth, uniform grains are formed on the quartz glass substrates through PLD technique. The grain size of ZnS deposited by PLD is much smaller than that of CdS by conventional CBD method, which is analyzed as the main reason of detrimental cell performance. The composition of the ZnS films was also measured by X-ray fluorescence. The typical ZnS films obtained in this work are near stoichiometric and only a small amount of S-rich. The energy band gaps at different temperatures were obtained by absorption spectroscopy measurement, which increases from 3.2 eV to 3.7 eV with the increasing of the deposition temperature. ZnS has a wider energy band gap than CdS (2.4 eV), which can enhance the blue response of the photovoltaic cells. These results show the high-quality of these substitute buffer layer materials are prepared through an all-dry technology, which can be used in the manufacture of CIGS thin film solar cells.

  16. Optimization of CdS Buffer Layer for High Efficiency CIGS Solar Cells.

    Science.gov (United States)

    Kim, Donguk; Jang, Yong-Jun; Jung, Ho-Sung; Kim, Minha; Baek, Dohyun; Yi, Junsin; Lee, Jaehyeong; Choi, Youngkwan

    2016-05-01

    In present work, effects of the thickness on the structural and optical properties of chemically deposited CdS thin films were investigated. In addition, we fabricated Cu(In, Ga)Se2 solar cells with various thicknesses of CdS buffer layer and optimized the thickness for a high efficiency. When the CdS thin films were thicker, the crystallinity improved but the transmittance decreased. The short-circuit current density (J(sc)) and the fill factor are the major efficiency limiting factors for the CIGS solar cells. As the thickness of the CdS buffer layer, the open-circuit voltage (V(oc)) and the fill factor increased, whereas the J(sc) slightly decreased. The improvement of the fill factor and thus efficiency resulted from larger shunt resistance. For the solar cells without a high resistive intrinsic ZnO layer, the highest efficiency was acquired at the thickness of 89 nm. With further increasing the thickness, the J(sc) decreased significantly, resulting in poor efficiency.

  17. Simulation Study of Effects, Operating Temperature and Layer Thickness on Thin Film CIGS Solar Cell Performance

    Directory of Open Access Journals (Sweden)

    A.D. Pogrebnjak

    2011-01-01

    Full Text Available SCAPS- program is designed basically for the simulation and studying the properties of photonic devices. We explored the important controllable design parameters affecting the performance of the hetero junction solar cells, as operating temperature that we noticed increasing in J-V characteristics by increasing T, the effect of thickness of each layer on the performance of the cell was studied, an increasing of J-V characteristics with increasing p-layer , In the numerical example, 3 μm absorber layer and CdS layer 0.05 μm, ZnO layer 0.1 μm, works the best for given doping density, if we change the optimum value , the efficiency can reach to 17.72 % with FF 83.88 %, Voc = 0.725 Volt, Jsc = 29.07 mA/cm2 at 300 K, in this case, we have come out the optimum parameters to achieve the best performance of this type of cell, and then to made comparison with practical CIGS cell.

  18. CIGS thin-film solar module processing: case of high-speed laser scribing

    Science.gov (United States)

    Gečys, Paulius; Markauskas, Edgaras; Nishiwaki, Shiro; Buecheler, Stephan; de Loor, Ronny; Burn, Andreas; Romano, Valerio; Račiukaitis, Gediminas

    2017-01-01

    In this paper, we investigate the laser processing of the CIGS thin-film solar cells in the case of the high-speed regime. The modern ultra-short pulsed laser was used exhibiting the pulse repetition rate of 1 MHz. Two main P3 scribing approaches were investigated - ablation of the full layer stack to expose the molybdenum back-contact, and removal of the front-contact only. The scribe quality was evaluated by SEM together with EDS spectrometer followed by electrical measurements. We also modelled the electrical behavior of a device at the mini-module scale taking into account the laser-induced damage. We demonstrated, that high-speed process at high laser pulse repetition rate induced thermal damage to the cell. However, the top-contact layer lift-off processing enabled us to reach 1.7 m/s scribing speed with a minimal device degradation. Also, we demonstrated the P3 processing in the ultra-high speed regime, where the scribing speed of 50 m/s was obtained. Finally, selected laser processes were tested in the case of mini-module scribing. Overall, we conclude, that the top-contact layer lift-off processing is the only reliable solution for high-speed P3 laser scribing, which can be implemented in the future terawatt-scale photovoltaic production facilities.

  19. Effect of electrodeposition potential on composition and morphology of CIGS absorber thin film

    Indian Academy of Sciences (India)

    N D Sang; P H Quang; L T Tu; D T B Hop

    2013-08-01

    CuInGaSe (CIGS) thin films were deposited on Mo/soda-lime glass substrates by electrodeposition at different potentials ranging from −0.3 to −1.1 V vs Ag/AgCl. Cyclic voltammetry (CV) studies of unitary Cu, Ga, In and Se systems, binary Cu–Se, Ga–Se and In–Se systems and quaternary Cu–In–Ga–Se were carried out to understand the mechanism of deposition of each constituent. Concentration of the films was determined by energy dispersive spectroscopy. Structure and morphology of the films were characterized by X-ray diffraction and scanning electron microscope. The underpotential deposition mechanism of Cu–Se and In–Se phases was observed in voltammograms of binary and quaternary systems. Variation in composition with applied potentials was explained by cyclic voltammetry (CV) data. A suitable potential range from −0.8 to −1.0 V was found for obtaining films with desired and stable stoichiometry. In the post-annealing films, chalcopyrite structure starts forming in the samples deposited at −0.5 V and grows on varying the applied potential towards negative direction. By adjusting the composition of electrolyte, we obtained the desired stoichiometry of Cu(In0.7Ga0.3)Se2.

  20. Improving Performance of CIGS Solar Cells by Annealing ITO Thin Films Electrodes

    Directory of Open Access Journals (Sweden)

    Chuan Lung Chuang

    2015-01-01

    Full Text Available Indium tin oxide (ITO thin films were grown on glass substrates by direct current (DC reactive magnetron sputtering at room temperature. Annealing at the optimal temperature can considerably improve the composition, structure, optical properties, and electrical properties of the ITO film. An ITO sample with a favorable crystalline structure was obtained by annealing in fixed oxygen/argon ratio of 0.03 at 400°C for 30 min. The carrier concentration, mobility, resistivity, band gap, transmission in the visible-light region, and transmission in the near-IR regions of the ITO sample were -1.6E+20 cm−3, 2.7E+01 cm2/Vs, 1.4E-03 Ohm-cm, 3.2 eV, 89.1%, and 94.7%, respectively. Thus, annealing improved the average transmissions (400–1200 nm of the ITO film by 16.36%. Moreover, annealing a copper-indium-gallium-diselenide (CIGS solar cell at 400°C for 30 min in air improved its efficiency by 18.75%. The characteristics of annealing ITO films importantly affect the structural, morphological, electrical, and optical properties of ITO films that are used in solar cells.

  1. Long-term performance data and analysis of CIS/CIGS modules deployed outdoors

    Science.gov (United States)

    del Cueto, J. A.; Rummel, S.; Kroposki, B.; Anderberg, A.

    2008-08-01

    The long-term performance data of copper indium diselenide (CIS) and gallium-alloyed CIS (CIGS) photovoltaic (PV) modules are investigated to assess the reliability of this technology. We study and report on numerous PV modules acquired from two manufacturers (A and B), deployed at NREL's outdoor test facility (OTF) in various configurations in the field: some are free standing, loaded with a fixed resistance and periodically tested indoors at STC; other modules are connected to data acquisition systems with their performance continuously monitored. Performance is characterized using current-voltage (I-V) measurements obtained either at standard test conditions or under real-time monitoring conditions: the power parameters plus other factors relating to quality like diode quality factors or series resistance are analyzed for changes against time. Using standard diode analysis to determine the sources of degradation indicates that CIS modules can exhibit between moderate and negligible degradation, with the dominant loss mode being fill factor declines along with decreases in open-circuit voltage, for illumination intensities near 1-sun. At lower intensities, current losses can appear appreciable. The real-time performance data also indicate that fill factor loss is the primary degradation mode, generally as a result of increases in series resistance.

  2. Long-term performance analysis of CIGS thin-film PV modules

    Science.gov (United States)

    Dhere, Neelkanth G.; Kaul, Ashwani; Pethe, Shirish A.

    2011-09-01

    Current accelerated qualification tests of photovoltaic (PV) modules mostly assist in avoiding infant mortality but can neither duplicate changes occurring in the field nor can predict useful lifetime. Therefore, outdoor monitoring of fielddeployed thin-film PV modules was undertaken at FSEC with goals of assessing their performance in hot and humid climate under high system voltage operation and to correlate the PV performance with the meteorological parameters. Significant and comparable degradation rate of -5.13% and -4.5% per year was found by PV USA type regression analysis for the positive and negative strings respectively of 40W glass-to-glass CIGS thin-film PV modules in the hot and humid climate of Florida. With the current-voltage measurements it was found that the performance degradation within the PV array was mainly due to a few (8-12%) modules having a substantially high degradation. The remaining modules within the array continued to show reasonable performance (>96% of the rated power after ~ 4years).

  3. Unlikely Combination of Experiments With a Novel High-Voltage CIGS Photovoltaic Array: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    del Cueto, J. A.; Sekulic, B. R.

    2006-05-01

    A new high-voltage array comprising bipolar strings of copper indium gallium diselenide (CIGS) photovoltaic (PV) modules was inaugurated in 2005. It is equipped with a unique combination of tests, which likely have never before been deployed simultaneously within a single array: full current-voltage (I-V) traces, high-voltage leakage current measurements, and peak-power tracking or temporal stepped-bias profiling. The array nominally produces 1 kW power at 1 sun. The array's electrical characteristics are continuously monitored and controlled with a programmable electronic load interfaced to a data acquisition system (DAS), that also records solar and meteorological data. The modules are mounted with their frames electrically isolated from earth ground, in order to facilitate measurement of the leakage currents that arise between the high voltage bias developed in the series-connected cells and modules and their mounting frames. Because the DAS can perform stepped biasing of the array as a function of time, synchronous detection of the leakage current data with alternating bias is available. Leakage current data and their dependence on temperature and voltage are investigated. Array power data are analyzed across a wide range of varying illuminations and temperatures from the I-V traces. Array performance is also analyzed from an energy output perspective using peak-power tracking data.

  4. CIGS thin-film solar module processing: case of high-speed laser scribing

    Science.gov (United States)

    Gečys, Paulius; Markauskas, Edgaras; Nishiwaki, Shiro; Buecheler, Stephan; De Loor, Ronny; Burn, Andreas; Romano, Valerio; Račiukaitis, Gediminas

    2017-01-01

    In this paper, we investigate the laser processing of the CIGS thin-film solar cells in the case of the high-speed regime. The modern ultra-short pulsed laser was used exhibiting the pulse repetition rate of 1 MHz. Two main P3 scribing approaches were investigated – ablation of the full layer stack to expose the molybdenum back-contact, and removal of the front-contact only. The scribe quality was evaluated by SEM together with EDS spectrometer followed by electrical measurements. We also modelled the electrical behavior of a device at the mini-module scale taking into account the laser-induced damage. We demonstrated, that high-speed process at high laser pulse repetition rate induced thermal damage to the cell. However, the top-contact layer lift-off processing enabled us to reach 1.7 m/s scribing speed with a minimal device degradation. Also, we demonstrated the P3 processing in the ultra-high speed regime, where the scribing speed of 50 m/s was obtained. Finally, selected laser processes were tested in the case of mini-module scribing. Overall, we conclude, that the top-contact layer lift-off processing is the only reliable solution for high-speed P3 laser scribing, which can be implemented in the future terawatt-scale photovoltaic production facilities. PMID:28084403

  5. EffiCiency and Safety of an eLectronic cigAreTte (ECLAT as tobacco cigarettes substitute: a prospective 12-month randomized control design study.

    Directory of Open Access Journals (Sweden)

    Pasquale Caponnetto

    Full Text Available BACKGROUND: Electronic cigarettes (e-cigarettes are becoming increasingly popular with smokers worldwide. Users report buying them to help quit smoking, to reduce cigarette consumption, to relieve tobacco withdrawal symptoms, and to continue having a 'smoking' experience, but with reduced health risks. Research on e-cigarettes is urgently needed in order to ensure that the decisions of regulators, healthcare providers and consumers are based on science. Methods ECLAT is a prospective 12-month randomized, controlled trial that evaluates smoking reduction/abstinence in 300 smokers not intending to quit experimenting two different nicotine strengths of a popular e-cigarette model ('Categoria'; Arbi Group Srl, Italy compared to its non-nicotine choice. GroupA (n = 100 received 7.2 mg nicotine cartridges for 12 weeks; GroupB (n = 100, a 6-week 7.2 mg nicotine cartridges followed by a further 6-week 5.4 mg nicotine cartridges; GroupC (n = 100 received no-nicotine cartridges for 12 weeks. The study consisted of nine visits during which cig/day use and exhaled carbon monoxide (eCO levels were measured. Smoking reduction and abstinence rates were calculated. Adverse events and product preferences were also reviewed. RESULTS: Declines in cig/day use and eCO levels were observed at each study visits in all three study groups (p<0.001 vs baseline, with no consistent differences among study groups. Smoking reduction was documented in 22.3% and 10.3% at week-12 and week-52 respectively. Complete abstinence from tobacco smoking was documented in 10.7% and 8.7% at week-12 and week-52 respectively. A substantial decrease in adverse events from baseline was observed and withdrawal symptoms were infrequently reported during the study. Participants' perception and acceptance of the product under investigation was satisfactory. CONCLUSION: In smokers not intending to quit, the use of e-cigarettes, with or without nicotine, decreased cigarette consumption

  6. Adhesion, resistivity and structural, optical properties of molybdenum on steel sheet coated with barrier layer done by sol–gel for CIGS solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Amouzou, Dodji, E-mail: dodji.amouzou@fundp.ac.be [Research Centre in Physics of Matter and Radiation (PMR), University of Namur (FUNDP), Rue de Bruxelles 61, 5000 Namur (Belgium); Dumont, Jacques [Research Centre in Physics of Matter and Radiation (PMR), University of Namur (FUNDP), Rue de Bruxelles 61, 5000 Namur (Belgium); Fourdrinier, Lionel; Richir, Jean-Baptiste; Maseri, Fabrizio [CRM-Group, Boulevard de Colonster, B 57, 4000 Liège (Belgium); Sporken, Robert [Research Centre in Physics of Matter and Radiation (PMR), University of Namur (FUNDP), Rue de Bruxelles 61, 5000 Namur (Belgium)

    2013-03-01

    Molybdenum films are investigated on stainless steel substrates coated with polysilazane based sol–gel and SiO{sub x} layers for flexible CIGS solar cell applications. Thermal stability of the multilayer has been studied. The thickness of polysilazane films are significantly reduced (17%) after heat treatment suggesting a thermal degradation. Four different microstructures were found for Mo films by varying argon total pressure from 2.6 × 10{sup −1} Pa to 2.6 Pa. It was shown that continuous films, low sheet resistance (0.5 Ω/□) and well facetted grains can be achieved when Mo films are deposited on heated substrates at homologous temperature, T of 0.2. - Highlights: ► Steel sheet is functionalized for Cu[Inx,Ga(1 − x)Se2] solar cells. ► Varying deposition pressure impacts the microstructure of Mo films. ► High thermal stability of the sol gel based barrier layer has been investigated. ► Low sheet resistance and continuous Mo films have been obtained at 550°C. ► Thermal stability of functionalized steel sheets at 550°C has been investigated.

  7. Preparation and optimization of a molybdenum electrode for CIGS solar cells

    Directory of Open Access Journals (Sweden)

    Feng Jingxue

    2016-11-01

    Full Text Available Molybdenum (Mo films were deposited by radio frequency (RF, direct current (DC and mixed magnetron sputtering, respectively. With changing the deposition parameters including deposition pressure and power, the films show different surface morphology and crystallinity. Lower resistivity of the films is obtained in the DC mode and better reflectivity of the films is obtained in the RF mode. It is shown that the crystallinity increases when the deposition pressure decreases. The crystallinity and the grain size both increase as the deposition power increasing. The lowest resistivity of the single Mo film is 34×10-6 Ω·cm when the deposition pressure is 0.1 Pa and the deposition power is 300 W in the DC mode. In order to obtain lower resistivity, better adhesion and better reflectivity, bilayer films and tri-layer films were both deposited in different mode. They all show good adhesion and low resistivity. The Mo films deposited in mixed mode show better reflectivity. It is demonstrated that the resistivity of about 65×10-6 Ω·cm is achieved in DC/RF mode and the resistivity of about 61×10-6 Ω·cm is achieved in RF/DC/RF mode. And the tri-layer films achieved in RF/DC/RF mode have better reflectivity than bilayer films achieved in DC/RF mode. The tri-layer films achieved in RF/DC/RF mode is appropriate for using as the electrode of CIGS solar cells.

  8. Flexible CIGS solar cells on large area polymer foils with in-line deposition methods and application of alternative back contacts - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Tiwari, A. N.

    2009-08-15

    This illustrated report for the Swiss Federal Office of Energy (SFOE) summarises the work performed within this project and also reports on synergies with other projects that helped to make a significant contribution to the development of CIGS thin film solar cells on flexible substrates such as polymer foils. The project's aims were to learn more about up-scaling issues and to demonstrate the abilities required for the processing of layers on large area polyimide foils for flexible CIGS solar cells. Custom-built evaporators that were designed and constructed in-house are described. A CIGS system for in-line deposition was also modified for roll-to-roll deposition and alternative electrical back contacts to conventional ones were evaluated on flexible polyimide foils. The objectives of the project and the results obtained are looked at and commented on in detail.

  9. Primera cita de reproducción de cigüeñuela común Himantopus himantopus L., 1758 en Urdaibai (Bizkaia

    Directory of Open Access Journals (Sweden)

    ARIZAGA, J., AZKONA, A., CEPEDA, X., MAGUREGI, J., UNAMUNO, E., UNAMUNO, J.M.

    2012-01-01

    Full Text Available La colonización del Cantábrico por la cigüeñuela común Himantopus himantopus L., 1758 es un fenómeno reciente (se cita por primera vez en 2009 en Asturias y Cantabria. En 2012, y por primera vez para Urdaibai y la costa vasca, se constata la reproducción de cigüeñuela en la laguna de Orueta, en el municipio de Gautegiz-Arteaga (Bizkaia. En particular, una pareja fue capaz de sacar adelante 3 pollos.

  10. RESEARCH ON CIS AND CIGS THIN FILM SOLAR CELLS%CIS和CIGS薄膜太阳电池的研究

    Institute of Scientific and Technical Information of China (English)

    孙云; 王俊清; 杜兆峰; 舒保健; 于刚; 温国忠; 周祯华; 孙健; 李长健; 张丽珠

    2001-01-01

    P type CIS and CIGS thin films are fabricated by evaporating selenylation method,and so are N type CdS.They compose heterogeneity PN junction solar cells.After annealing,the cells'efficiencies reach 8.83%and 9.13% respectively.CIS Fabricating technology and key problems are discussed.The opinions about annealing are given in this article.%采用蒸发硒化方法制备了P型CIS(铜铟硒)和CIGS(铜铟镓硒)薄膜,用蒸发法制备N型CdS(硫化镉),二者组成异质PN结太阳电池。经退火处理,CIS和CIGS薄膜太阳电池的效率分别达到8.83%和9.13%。对制膜过程中衬底的选择,背电极的制备,CIS各元素蒸发控制和镓的掺入等工艺技术问题进行了深入的讨论,对电池的退火处理提出了自己的见解。

  11. A ~ 12 kpc HI extension and other HI asymmetries in the isolated galaxy CIG 340 (IC 2487)

    CERN Document Server

    Scott, T C; Montenegro, L Verdes; Bosma, A; Athanassoula, E; Sulentic, J; Espada, D; Yun, M S; Argudo-Fernandez, M

    2014-01-01

    HI kinematic asymmetries are common in late-type galaxies irrespective of environment, although the amplitudes are strikingly low in isolated galaxies. As part of our studies of the HI morphology and kinematics in isolated late-type galaxies we have chosen several very isolated galaxies from the AMIGA sample for HI mapping. Here we present GMRT 21-cm HI line mapping of CIG 340 which was selected because its integrated HI spectrum has a very symmetric profile, Aflux = 1.03. Optical images of the galaxy hinted at a warped disk in contrast to the symmetric integrated HI spectrum profile. Our aim is to determine the extent to which the optical asymmetry is reflected in the resolved HI morphology and kinematics. GMRT observations reveal significant HI morphological asymmetries in CIG 340 despite it's overall symmetric optical form and highly symmetric HI spectrum. The most notable HI features are: 1) a warp in the HI disk (with an optical counterpart), 2) the HI north/south flux ratio = 1.32 is much larger than ex...

  12. Recycling of indium from CIGS photovoltaic cells: potential of combining acid-resistant nanofiltration with liquid-liquid extraction.

    Science.gov (United States)

    Zimmermann, Yannick-Serge; Niewersch, Claudia; Lenz, Markus; Kül, Zöhre Zohra; Corvini, Philippe F-X; Schäffer, Andreas; Wintgens, Thomas

    2014-11-18

    Electronic consumer products such as smartphones, TV, computers, light-emitting diodes, and photovoltaic cells crucially depend on metals and metalloids. So-called "urban mining" considers them as secondary resources since they may contain precious elements at concentrations many times higher than their primary ores. Indium is of foremost interest being widely used, expensive, scarce and prone to supply risk. This study first investigated the capability of different nanofiltration membranes of extracting indium from copper-indium-gallium- selenide photovoltaic cell (CIGS) leachates under low pH conditions and low transmembrane pressure differences (98% by nanofiltration, separating it from parts of the Ag, Sb, Se, and Zn present. LLE using di-(2-ethylhexyl)phosphoric acid (D2EHPA) extracted 97% of the indium from the retentates, separating it from all other elements except for Mo, Al, and Sn. Overall, 95% (2.4 g m(-2) CIGS) of the indium could be extracted to the D2EHPA phase. Simultaneously, by nanofiltration the consumption of D2EHPA was reduced by >60% due to the metal concentration in the reduced retentate volume. These results show clearly the potential for efficient scarce metal recovery from secondary resources. Furthermore, since nanofiltration was applicable at very low pH (≥ 0.6), it may be applied in hydrometallurgy typically using acidic conditions.

  13. Highly efficient graphene-based Cu(In, Ga)Se₂ solar cells with large active area.

    Science.gov (United States)

    Yin, Ling; Zhang, Kang; Luo, Hailin; Cheng, Guanming; Ma, Xuhang; Xiong, Zhiyu; Xiao, Xudong

    2014-09-21

    Two-dimensional graphene has tremendous potential to be used as a transparent conducting electrode (TCE), owing to its high transparency and conductivity. To date graphene films have been applied to several kinds of solar cells except the Cu(In, Ga)Se₂ (CIGS) solar cell. In this work, we present a novel TCE structure consisting of a doped graphene film and a thin layer of poly(methyl methacrylate) (PMMA) to replace the ZnO:Al (AZO) electrode for CIGS. By optimizing the contact between graphene and intrinsic ZnO (i-ZnO), a high power conversion efficiency (PCE) of 13.5% has been achieved, which is among the highest efficiencies of graphene-based solar cells ever reported and approaching those of AZO-based solar cells. Besides, the active area of our solar cells reaches 45 mm(2), much larger than other highly efficient graphene-based solar cells (>10%) reported so far. Moreover, compared with AZO-based CIGS solar cells, the total reflectance of the graphene-based CIGS solar cells is decreased and the quantum efficiency of the graphene-based CIGS is enhanced in the near infrared region (NIR), which strongly support graphene as a competitive candidate material for the TCE in the CIGS solar cell. Furthermore, the graphene/PMMA film can protect the solar cell from moisture, making the graphene-based solar cells much more stable than the AZO-based solar cells.

  14. High-temperature stability of molybdenum (Mo) back contacts for CIGS solar cells: a route towards more robust back contacts

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Ju-Heon; Yoon, Kwan-Hee; Jeong, Jeung-hyun [Solar Cell Research Center, Korea Institute of Science and Technology, 39-1, Seoul 136-791 (Korea, Republic of); Kim, Won Mok; Park, Jong-Keuk; Baik, Young-Joon [Electronic Materials Research Center, Korea Institute of Science and Technology, 39-1, Seoul 136-791 (Korea, Republic of); Seong, Tae-Yeon, E-mail: jhjeong@kist.re.kr [Department of Materials Science and Engineering, College of Engineering, Korea University, Seoul 136-701 (Korea, Republic of)

    2011-10-26

    The thermal stability of Mo thin films is indispensable to Cu(In,Ga)Se{sub 2} (CIGS) solar cells: CIGS films are deposited above 500 deg. C. The thermal stabilities of Mo thin films with dense to porous Mo microstructures, which are varied by controlling the sputtering pressure, are investigated. Interface failures are found to occur in buckling mode in denser Mo films, whereas cracking arises in less dense films. The failure modes are apparently dependent on the sign of the residual stress: the former is due to compressive stress, whereas the latter is due to tensile stress. Interestingly, the softening of soda-lime glass at high temperatures reconfigures the film stresses to be more compressive after annealing, which in turn triggers buckling even in films that are tensile-stressed in the as-deposited states. We conclude that the appropriate processing conditions for thermally stable back contacts cannot be obtained with the simple single layer approach. On the basis of this relationship between microstructure, residual stress and the failure modes, it is shown that improvements in film adhesion can widen the processing window for the preparation of robust back contacts, i.e. with a conventional bilayer approach and substrate roughening. Since the bilayer approach employed more compliant porous structures in the bottom layer, back contacts that are better suited to higher stress and temperature can be produced. Furthermore, substrate roughening might make the back contact more conductive as well as more stable because adhesion can be enhanced without the use of an electrically resistive buffer layer.

  15. High throughput CIGS solar cell fabrication via ultra-thin absorber layer with optical confinement and (Cd, CBD)-free heterojunction partner

    Energy Technology Data Exchange (ETDEWEB)

    Marsillac, Sylvain [Old Dominion Univ., Norfolk, VA (United States)

    2015-11-30

    The main objective of this proposal was to use several pathways to reduce the production cost of Cu(In,Ga)Se2 (CIGS) PV modules and therefore the levelized cost of energy (LCOE) associated with this technology. Three high cost drivers were identified, nominally: 1) Materials cost and availability; 2) Large scale uniformity; 3) Improved throughput These three cost drivers were targeted using the following pathways: 1) Reducing the thickness of the CIGS layer while enhancing materials quality; 2) Developing and applying enhanced in-situ metrology via real time spectroscopic ellipsometry; 3) Looking into alternative heterojunction partner, back contact and anti-reflection (AR) coating Eleven main Tasks were then defined to achieve these goals (5 in Phase 1 and 6 in Phase 2), with 11 Milestones and 2 Go/No-go decision points at the end of Phase 1. The key results are summarized below

  16. Field modulation in Na-incorporated Cu(In,Ga)Se2 (CIGS) polycrystalline films influenced by alloy-hardening and pair-annihilation probabilities.

    Science.gov (United States)

    Jeong, Yonkil; Kim, Chae-Woong; Park, Dong-Won; Jung, Seung Chul; Lee, Jongjin; Shim, Hee-Sang

    2011-11-07

    The influence of Na on Cu(In,Ga)Se2 (CIGS) solar cells was investigated. A gradient profile of the Na in the CIGS absorber layer can induce an electric field modulation and significantly strengthen the back surface field effect. This field modulation originates from a grain growth model introduced by a combination of alloy-hardening and pair-annihilation probabilities, wherein the Cu supply and Na diffusion together screen the driving force of the grain boundary motion (GBM) by alloy hardening, which indicates a specific GBM pinning by Cu and Na. The pair annihilation between the ubiquitously evolving GBMs has a coincident probability with the alloy-hardening event.PACS: 88. 40. H-, 81. 10. Aj, 81. 40. Cd.

  17. Resolución no. 1141/08 : Llamado a concurso para designación de Directores de IGEVET, IBBM, CIG; CINDECA e INFIVE

    OpenAIRE

    Universidad Nacional de La Plata

    2008-01-01

    Llamado a concurso para la designación de Directores de los siguientes institutos de la UNLP: Instituto de Biotecnología Molecular (IBBM), Instituto de Genética Veterinaria (IGEVET), Centro de Investigaciones Geológicas (CIG), Centro de Investigación y Desarrollo en Ciencia Aplicada (CINDECA) e Instituto de Fisiología Vegetal (INFIVE), acompañado del listado de miembros sugeridos como jurados para cada uno de los concursos.

  18. Effector Protein Cig2 Decreases Host Tolerance of Infection by Directing Constitutive Fusion of Autophagosomes with the Coxiella-Containing Vacuole

    Directory of Open Access Journals (Sweden)

    Lara J. Kohler

    2016-07-01

    Full Text Available Coxiella burnetii replicates in an acidified lysosome-derived vacuole. Biogenesis of the Coxiella-containing vacuole (CCV requires bacterial effector proteins delivered into host cells by the Dot/Icm secretion system. Genetic and cell biological analysis revealed that an effector protein called Cig2 promotes constitutive fusion of autophagosomes with the CCV to maintain this compartment in an autolysosomal stage of maturation. This distinguishes the CCV from other pathogen-containing vacuoles that are targeted by the host autophagy pathway, which typically confers host resistance to infection by delivering the pathogen to a toxic lysosomal environment. By maintaining the CCV in an autolysosomal stage of maturation, Cig2 enabled CCV homotypic fusion and enhanced bacterial virulence in the Galleria mellonella (wax moth model of infection by a mechanism that decreases host tolerance. Thus, C. burnetii residence in an autolysosomal organelle alters host tolerance of infection, which indicates that Cig2-dependent manipulation of a lysosome-derived vacuole influences the host response to infection.

  19. Presence of central nervous system tissues as bovine spongiform encephalopathy specified risk material in Turkish raw meat ball (cig kofte

    Directory of Open Access Journals (Sweden)

    Ahmet Hulusi DİNÇOĞLU

    2016-01-01

    Full Text Available Abstract Bovine Spongiform Encephalopathy (BSE is a virulent disease which may infect by affecting the central nervous system (CNS tissues in cattle and causes degeneration in nerves. Central nervous system tissues such as brain and spinal cord which are classified as specified risk materials (SRMs are regarded to be main source of infection. The contamination of the meat with the specific risk materials (SRMs can occur in phases of slaughter, fragmentation of carcass and processing. This study was conducted in order to investigate the existence of CNS tissues in raw meat ball (cig kofte which is commonly consumed in the Southeastern Region of Turkey, particularly in Şanlıurfa. For this purpose, 145 samples of raw meat ball were tested. The enzyme-linked immunosorbent assay (ELISA kits (Ridascreen risk material 10/5, R-biofarm GmbH which determine glial fibrillary acidic protein (GFAP as determinant were used. As a result of the analyses, positivity was detected in 21 of totally 145 samples of raw meat ball (14.48%. 6 (4.14% of the samples gave low level of positivity (≥ 0.1 standard absorbance, 10 (6.90% gave medium level of positivity (>0.2 standard absorbance and 5 (3.45% gave high level of positivity (≥0.5 standard absorbance. As a consequence, meats are contaminated in any phase of both slaughter and meat production even if accidentally. Regarding this matter, necessary measures should be taken and hygiene rules should be applied.

  20. Effect of Se Vapor Concentration on CIGS Film Preparation%硒蒸气浓度对制备CIGS薄膜的影响

    Institute of Scientific and Technical Information of China (English)

    廖成; 韩俊峰; 江涛; 谢华木; 焦飞; 赵夔

    2011-01-01

    We applied the “selenization of stack element layers” method to the preparation of CuIn1-xGaxSe2 (CIGS) films.The selenium vapor concentration was precisely controlled to optimize the annealing process using a homemade bilayer tubular selenization facility, and its effect on the photoelectric characteristics of the films was studied.Auger electron spectroscopy (AES) and X-ray diffraction (XRD) were used to analyze the composition distribution in the cross-section and to obtain phase information, respectively.The output performance of the CIGS device was also measured under AM1.5 1000 W·m-2 illumination.The results indicated that the molybdenum back contact layer was seriously degraded by the saturated selenium vapor during annealing.Annealing with a low concentration of selenium vapor led to bad performance because of segregation and defects in the film.The CIGS film was homogeneous after annealing in a selenium-free inert atmosphere and a conversion efficiency of 8.5% was obtained.%采用"预制层硒化法"制备Culn1-xGaxSe2(CIGS)薄膜,基于自主设计的"双层管式硒化装置",通过控制硒蒸气浓度优化退火工艺,研究硒蒸气浓度对薄膜光电性能的影响,利用俄歇电子能谱(AES)和X射线衍射分析(XRD)等手段对不同硒浓度氛围下生成的CIGS薄膜的成分和物相进行表征,并在AM1.5、1000 W·m-2的标准光照条件下比较相应CIGS电池器件的输出性能,实验结果表明:饱和硒蒸气下退火得到的样品,基底钼膜遭到严重腐蚀破坏,失去背电极功能;在低浓度硒气氛下退火不能有效消除CIGS薄膜的偏析和缺陷,以致光电转换效率低;而在无硒惰性氛围下退火的样品,生成了物相均一化的CIGS薄膜,由此制备的CIGS电池取得了8.5%的转换效率.

  1. Research on fabrication technology for thin film solar cells for practical use. Technological development for qualitative improvement (CuInSe2 based PV cell); Usumaku taiyo denchi seizo gijutsu no jitsuyoka kenkyu. Kohinshitsuka gijutsu (CuInSe2 taiyo denchi seizo 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 the fabrication technology of CuInSe2 based PV cell in fiscal 1994. (1) On formation of high-quality CIGS thin films by bilayer method, Mo film was deposited on a glass substrate by sputtering, and CIGS film with different Ga/In ratios was next formed on the substrate by quaternary simultaneous deposition at different In and Ga deposition speeds. In addition, CdS film was deposited on the CIGS film, and ZnO and ITO films were finally deposited on it by sputtering to complete solar cell. This solar cell offered the maximum conversion efficiency among cells using CIGS film. (2) On formation of high-quality CIGS thin films by three-stage method, a certain correlation was found between substrate temperature and CIGS film composition by monitoring substrate temperature in film forming process. This phenomenon allowed rigorous control of CIS film compositions important for CIS thin film solar cells. (3) On low-cost process technology for thin film formation, Cu(In,Ga)S2 solid solution film was fabricated by expanded selenic process. 3 figs.

  2. Primeros datos sobre movimientos de cigüeñas blancas Ciconia ciconia L., 1758 anilladas como pollos en nido en Navarra: 2012-2015.

    Directory of Open Access Journals (Sweden)

    Jaime Resano-Mayor, Juan M. Barbarín, Daniel Alonso, Blanca Fernández-Eslava, Diego Villanua, Jesús Mari Lekuona, Ricardo Rodríguez,

    2016-01-01

    (i.e., avistamientos como muertos (i.e., recuperaciones, en su mayoría por electrocución. Todos los avistamientos, excepto tres, se realizaron en vertederos (n = 64, en donde el esfuerzo de muestreo fue considerablemente mayor. Dos avistamientos correspondieron a cigüeñas observadas en humedales, así como otro ejemplar que se observó dos años después en la colonia donde nació (i.e., reclutamiento. La distancia promedio de avistamiento en relación a la colonia de anillamiento fue de 48 km (distancia máxima, 410 km. La mayoría de avistamientos/recuperaciones se realizó durante la primavera y verano, con independencia de la edad. Todas las aves que se hallaron muertas (n = 7 fueron jóvenes encontrados en la proximidad de sus colonias de nacimiento.

  3. Electronic level alignment at the deeply buried absorber/Mo interface in chalcopyrite-based thin film solar cells

    Science.gov (United States)

    Bär, M.; Nishiwaki, S.; Weinhardt, L.; Pookpanratana, S.; Shafarman, W. N.; Heske, C.

    2008-07-01

    We have investigated the electronic structure of the absorber/back contact interface for S-free [Cu(In ,Ga)Se2 ("CIGSe")] and S-containing [Cu(In ,Ga)(S,Se)2 ("CIGSSe")] chalcopyrites with direct and inverse photoemission. Comparison of the electronic levels of the cleavage planes reveals a pronounced cliff in the conduction band at the CIG(S )Se/Mo interface. For the valence band, we find a flat alignment and a small spike for the CIGSe- and CIGSSe-based structures, respectively.

  4. Understanding the Effect of Na in Improving the Performance of CuInSe2 Based Photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Dobson, Kevin D. [Univ. of Delaware, Newark, DE (United States)

    2015-11-17

    Cu(In,Ga)Se2 (CIGS) thin film photovoltaic technology is in the early stages of commercialization with an annual manufacturing capacity over 1 GW and has demonstrated the highest module efficiency of any of the thin film technologies. However there still is a lack of fundamental understanding of the relationship between the material properties and solar cell device operation. It is well known that the incorporation of a small amount of Na into the CIGS film during processing is essential for high efficiency devices. However, there are conflicting explanations for how Na behaves at the atomic scale. This report investigates how Na is incorporated into the CIGS device structure and evaluates the diffusion of Na into CIGS grain boundaries (GBs) and bulk crystallites. Participants: This project was carried out at the Institute of Energy Conversion at the University of Delaware, collaborating with the Rockett group at the University of Illinois Urbana-Champagne. Significant Findings: The significant outcomes of this project for each task include; Task 1.0: Effect of Na in Devices Fabricated on PVD Deposited CIGS; Na diffusion occurs through the Mo back contact via GBs driven by the presence of oxygen; Na reversibly compensates donor defects in CIGS GBs,Task 2.0: Na Incorporation in Single Crystal CIGS; and bulk Na diffusion proceeds rapidly such that grains are Na-saturated immediately following CIGS thin film manufacture. Industry Guidance: The presented results offer interesting concepts for modification of manufacturing processes of CIGS-based PV modules. Possible approaches to improve control of Na uptake and uniformly increase levels in CIGS films are highlighted for processes that employ either soda-lime glass or NaF as the Na source. Concepts include the potential of O2 or oxidative based treatments of Mo back contacts to improve Na diffusion through the metal film and increase Na uptake into the growing CIGS. This project has also offered

  5. Influencia de la maduración del fruto de Arbutus xalapensis Kunth sobre la germinación de semillas y embriones cigóticos

    Directory of Open Access Journals (Sweden)

    Violeta Tovar-Rocha

    2015-07-01

    Full Text Available En este trabajo se determinó el efecto del estado de maduración del fruto en la germinación in vitro de semillas y embriones cigóticos deArbutus xalapensisKunt. Se colectaron frutos de 10 árboles en cada uno de los dos sitios de estudio y se clasifi caron según su tamaño y peso dentro de tres grupos caracterizados por el color del fruto: 1 a 6 frutos verde oscuro (FVO, 7 y 8 frutos verde-amarillo (FVA, y 9 y 10 frutos naranja-rojizo (FNR. De cada estado se seleccionaron 50 semillas y se colocaron en medio MS para evaluar su germinación. El experimento se repitió dos veces y los resultados obtenidos fueron sometidos a un análisis de comparación de medias de Tukey el cual indicó que los tres grupos de frutos presentan características de peso fresco y diámetro diferentes (P = 0.05, con un promedio de 6.3 g y de 0.21 mm para FVO, 9.5 g y 0.46 mm para FVA y 10.8 g y 0.70 mm para FNR. El análisis de microscopía estereoscópica demostró que todos los estados de maduración presentan semillas y embriones; los estados 1 al 4 presentan embriones no desarrollados, y en los estados 5 al 10 los frutos contienen un mayor número de semillas con embriones desarrollados y con una mayor germinación (7.6 a 8.8 semillas/unidad experimental. Se propone el uso de semillas provenientes de frutos de los estados de maduración 5 al 10 para la germinación adecuada de semillas de madroño, mientras que para los embriones cigóticos es necesario realizar estudios de prueba de medios de cultivo para su germinación.

  6. Research Progress on Buffer Layer Materials of CIGS Thin Film Solar Cell%CIGS薄膜太阳能电池缓冲层材料的研究进展

    Institute of Scientific and Technical Information of China (English)

    王卫兵; 刘平; 李伟; 马凤仓; 刘新宽; 陈小红

    2012-01-01

    CIGS薄膜太阳能电池的缓冲层为低带隙CIGS吸收层与高带隙ZnO窗口层之间形成过渡,减少两者带隙的晶格失配和带隙失调,并可防止溅射ZnO窗口层时给CIGS吸收层带来损害等,对提高CIGS薄膜太阳能电池效率起了重要作用.介绍了CIGS薄膜太阳能电池缓冲层材料的分类和制备工艺,主要阐述了CdS、ZnS及In2S3薄膜缓冲层材料及化学水浴法、原子层化学气相沉积法、金属化合物化学气相沉积法等制备工艺的研究现状,最后指出CIGS太阳能电池缓冲层在制备工艺、环境保护及大规模工业化生产中遇到的问题,并展望了其发展方向.%The buffer layers of CTGS thin film solar cells can form transition layers between low band gap CIGS absorber layers and high band gap of ZnO window layers, which reduces the lattice matching and band gap difference, and prevents damage of CIGS absorber layer from sputtering ZnO window layer, and therefore plays an important role in improving efficiency of CIGS thin film solar cells. Classification and preparation technology of CIGS thim film solar cells material are discussed, including the research progress of CdS,ZnS and In2S3 thin film buffer layer materials, and chemical bath deposition (CBD), atomic layer chemical vapor deposition (ALCVD), metal organic chemical vapor deposition (MOCVD) and other preparation technologies. The problems and development directions of buffer layer materials of CIGS thin film solar cells in preparation process, environment protection and large-scale industrial production are finally prospected.

  7. Performance Comparison of Stion CIGS Modules to Baseline Monocrystalline Modules at the New Mexico Florida and Vermont Regional Test Centers: January 2015-December 2016.

    Energy Technology Data Exchange (ETDEWEB)

    Lave, Matthew Samuel [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Stein, Joshua [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Burnham, Laurie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-01-01

    This report provides performance data and analysis for two Stion copper indium gallium selenide (CIGS) module types, one framed, the other frameless, and installed at the New Mexico, Florida and Vermont RTCs. Sandia looked at data from both module types and compared the latter with data from an adjacent monocrystalline baseline array at each RTC. The results indicate that the Stion modules are slightly outperforming their rated power, with efficiency values above 100% of rated power, at 25degC cell temperatures. In addition, Sandia sees no significant performance differences between module types, which is expected because the modules differ only in their framing. In contrast to the baseline systems, the Stion strings showed increasing efficiency with increasing irradiance, with the greatest increase between zero and 400 Wm -2 but still noticeable increases at 1000 Wm -2 . Although baseline data availability in Vermont was spotty and therefore comparative trends are difficult to discern, the Stion modules there may offer snow- shedding advantages over monocrystalline-silicon modules but these findings are preliminary.

  8. Zn1-xMgxO用于CIGS太阳电池的研究进展%Developments of CIGS Solar Cells with Zn1-xMgxO Films

    Institute of Scientific and Technical Information of China (English)

    江秋怡; 王卿璞; 王汉斌; 王丹丹; 武丽伟; 李福杰

    2013-01-01

    Zn1-xMgxO透过率高、带隙可调,且与CIGS太阳电池在晶格和能带结构上匹配良好,可用作CIGS太阳电池缓冲层、窗口层,因此制备高质量的Zn1-xMgxO薄膜是提高太阳电池性能的关键.文章介绍了Zn1-xMgxO薄膜的结构特性、光学特性及制备方法;从Mg含量、Zn1-xMgxO膜厚及Zn1-xMgxO/CIGS界面处缺陷密度等方面概述了Zn1-xMgxO用于CIGS太阳电池的研究进展,并比较了Zn1-xMgxO与In2S3,ZnS,CdS等其他材料作缓冲层的CIGS太阳电池性能的差别.%With high transparency,adjustable band gap and good match with CIGS in lattice and energy band structure,Zn1-xMgxO is regarded as the suitable material for the buffer layer and window layer of CIGS solar cells,so the fabrication of high quality Zn1-xMgxO films becomes to be the key problem for improving the efficiency of CIGS solar cells.In this paper,the preparation methods and structural and optical characteristics of Zn1-xMgxO films are introduced;and also the effects of concentration of Mg,the film thickness and the defect density on solar cells are summarized.As well it is compared the performance of solar cells with Zn1-xMgxO buffer layer with those applying other buffer layer materials.

  9. Analysis of Effects Resulted from Changing the Buffer Layer Material on Optimization of Cu (In 1-x,Gax Se2 Thin Filmsolar cell(CIGS and Simulation of Cell Structure

    Directory of Open Access Journals (Sweden)

    Nafise Shams

    2013-12-01

    Full Text Available Due tothe present globalunderstandingabout utilization ofrenewable energysources as constantcleanones, PVpowerhas beenthefocused bymanyresearch centers. Research of developmentofPhotovoltaic Energyis generally done in tow fields:reducingcosts andincreasing efficiency. CIGS thin film solar cells are of particular importance among the other types of the same category, due to the flexibility and yields of about 20%.Thispaper examines theperformance ofnanostructuredCIGSsolarcellsare discussed. The impact of changing material in the buffer layer of cell structure on electrical properties and the overall performance is evaluated. The optimized efficiency is also determined using simulation tools.

  10. Obtención de estructuras calcopirita (CIGS) y kesterita (CZTS) como absorbentes para dispositivos fotovoltaicos de capa fina mediante métodos de síntesis de bajo coste

    OpenAIRE

    Martí Valls, Rafael

    2016-01-01

    La presente tesis se basa en la obtención de materiales absorbentes para dispositivos fotovoltaicos de capa fina. Los compuestos absorbentes estudiados han sido Cu(In0,7Ga0,3)Se2 (CIGS, calcopirita) y Cu2ZnSn(Se1-x,Sx)4 (CZTS, kesterita). En ella se han desarrollado diversos métodos químicos de obtención (sin vacío) como solvotermal/hidrotermal, sol-gel, hot-injection/ non-injection y co-precipitación de selenitos. Los materiales obtenidos han sido caracterizados estructuralmente, morfológica...

  11. Development of Electrodeposited CIGS Solar Cells: Cooperative Research and Development Final Report, CRADA Number CRD-09-357

    Energy Technology Data Exchange (ETDEWEB)

    Neale, Nathan [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-09-01

    At present, most PV materials are fabricated by vacuum technologies. Some of the many disadvantages of vacuum technology are complicated instrumentation, material waste, high cost of deposition per surface area, and instability of some compounds at the deposition temperature. Solution-based approaches for thin-film deposition on large areas are particularly desirable because of the low capital cost of the deposition equipment, relative simplicity of the processes, ease of doping, uniform deposition on a variety of substrates (including interior and exterior of tubes and various nonplanar devices), and potential compatibility with high-throughput (e.g., roll-to-roll) processing. Of the nonsilicon solar photovoltaic device modules that have been deployed to date, those based on the n-CdS/p-CdTe is a leading candidate. Two features in the optical characteristics of CdTe absorber are particularly attractive for photovoltaic conversion of sunlight; (a) its energy bandgap of 1.5 eV, which provides an optimal match with the solar spectrum and thus facilitates its efficient utilization and (b) the direct mode of the main optical transition which results in a large absorption coefficient and turn permits the use of thin layer (1-2 um) of active material. Thin films of CdTe required for these devices have been fabricated by a variety of methods (e.g., vapor transport deposition, vacuum deposition, screen printing and close-spaced sublimation). Electrodeposition is another candidate deserves more attention. This project will focus on delivering low-cost, high efficiency electrodeposited CdTe-based device.

  12. Methodology for Developing Evidence-Based Clinical Imaging Guidelines: Joint Recommendations by Korean Society of Radiology and National Evidence-Based Healthcare Collaborating Agency

    Science.gov (United States)

    Choi, Sol Ji; Jeong, Woo Kyoung; Jo, Ae Jeong; Choi, Jin A; Kim, Min-Jeong; Lee, Min; Jung, Seung Eun; Do, Kyung Hyun; Yong, Hwan Seok; Sheen, Seungsoo

    2017-01-01

    This paper is a summary of the methodology including protocol used to develop evidence-based clinical imaging guidelines (CIGs) in Korea, led by the Korean Society of Radiology and the National Evidence-based Healthcare Collaborating Agency. This is the first protocol to reflect the process of developing diagnostic guidelines in Korea. The development protocol is largely divided into the following sections: set-up, process of adaptation, and finalization. The working group is composed of clinical imaging experts, and the developmental committee is composed of multidisciplinary experts to validate the methodology. The Korean CIGs will continue to develop based on this protocol, and these guidelines will act for decision supporting tools for clinicians as well as reduce medical radiation exposure. PMID:28096730

  13. Electrodeposition of Mg doped ZnO thin film for the window layer of CIGS solar cell

    Science.gov (United States)

    Wang, Mang; Yi, Jie; Yang, Sui; Cao, Zhou; Huang, Xiaopan; Li, Yuanhong; Li, Hongxing; Zhong, Jianxin

    2016-09-01

    Mg doped ZnO (ZMO) film with the tunable bandgap can adjust the conduction band offset of the window/chalcopyrite absorber heterointerface to positive to reduce the interface recombination and resulting in an increasement of chalcopyrite based solar cell efficiency. A systematic study of the effect of the electrodeposition potential on morphology, crystalline structure, crystallographic orientation and optical properties of ZMO films was investigated. It is interestingly found that the prepared doped samples undergo a significant morphological change induced by the deposition potential. With negative shift of deposition potential, an obvious morphology evolution from nanorod structrue to particle covered films was observed. A possible growth mechanism for explaining the morphological change is proposed and briefly discussed. The combined optical techniques including absorption, transmission and photoluminescence were used to study the obtained ZMO films deposited at different potential. The sample deposited at -0.9 V with the hexagonal nanorods morphology shows the highest optical transparency of 92%. The photoluminescence spectra reveal that the crystallization of the hexagonal nanorod ZMO thin film deoposited at -0.9 V is much better than the particles covered ZMO thin film. Combining the structural and optical properties analysis, the obtained normal hexagonal nanorod ZMO thin film could potentially be useful in nanostructured chalcopyrite solar cells to improve the device performance.

  14. Funcionamiento hidrológico de un humedal ribereño, el Masegar, en el conjunto de los humedales de La Mancha Húmeda de la cuenca alta del rió Cigüela

    Directory of Open Access Journals (Sweden)

    Llamas, M. R.

    1995-12-01

    Full Text Available Fifteen years ago «La Mancha Húmeda» was deelared Biosphere Reserve by UNESCO, at the request of the Spanish Government. According to a recent deelaration by UNESCO in 1995, such title could be lost if the degradation processes of the wetlands of «La Mancha Húmeda» continue. «La Mancha Húmeda» was formed by a hundred of small lakes or wetlands that in area totalled about 200-300 km2 and they were distributed over an area of about 25.000 km2. These are different types of wetlands (saltwater and freshwater, permanent and ephimeral, riparian and closed basins, etc.. It is estimated that the actual surface of all the wetlands is about 20-30% of that occupied 20 or 30 years ago. The most famous degradation case is that of the «Tablas de Daimiel National Park» that has shrinked fram an area of about 15-20km2 to less than 1 km2 This article presents the general situation of the riverine wetlands of the Cigüela river and the results of the hydrological functioning of a wetland of modest dimensions, less than 1 km2, El Masegar. It is a riparian wetland located in the Cigüela River basin which has been severely affected by man actions. El Masegar can be considered as an artificial wetland. From an ecological point of view, this wetland seems to have been functioning in a proper way until 1988, when the so called «Plan de Regeneración Hídrica del Parque Nacional de las Tablas de Daimiel» began. This Plan has not regenerated the Natural Park but has degradated or destroyed the riparian wetlands that existed along the Cigüela River valley which is about ISO km long. The surface of these wetlands all together was larger than that of Tablas de Daimiel National Park. The study shows that it could be feasible to restore or maintain most of the riparian wetlands of the «La Mancha Húmeda» without a great economic investment and without social conflicts with the farmers.En 1981, a petición del Gobierno español, la

  15. Análisis a fatiga de un bulón en el interior de un pistón debido al movimiento del cigüeñal

    OpenAIRE

    Pérez García, Jairo

    2016-01-01

    El objetivo del presente trabajo de fin de grado es predecir la vida a fa-tiga del bulón en el interior de un pistón debido a las fuerzas producidas por el movimiento rotatorio del cigüeñal y simulando el conjunto de componentes como un mecanismo biela-manivela. Para la modelización virtual de las piezas se procederá a crearlas me-diante el software de dimensionado den 3 Autodesk Inventor. El propósito fi-nal será evaluar el bulón con el programa de análisis por elementos finitos Si-mulatio...

  16. Studies on chemical bath deposited CdS buffer layers for CIGS thin film solar cells%CIGS薄膜太阳能电池缓冲层CdS薄膜的制备研究

    Institute of Scientific and Technical Information of China (English)

    何丽秋

    2016-01-01

    目前CdS材料的制备方法有很多种,但是最常用的是化学水浴法。本文研究了浓度、反应溶液pH值、温度、沉积时间对CdS缓冲层薄膜的影响,对CIGS薄膜太阳能电池缓冲层CdS薄膜的制备方法进行了论述。%At present,the preparation methods of CdS has many kinds,The chemical bath deposition(CBD)is the most commonly method.In this review,the effects of concentration,pH,temperature and deposition time on the CdS buffer layer were studied.The preparation methods of CIGS thin film for CdS thin film solar cells were discussed.

  17. Bulk measurement of copper and sodium content in CuIn(0.7)Ga(0.3)Se(2) (CIGS) solar cells with nanosecond pulse length laser induced breakdown spectroscopy (LIBS)

    CERN Document Server

    Kowalczyk, Jeremy M D; DeAngelis, Alexander; Kaneshiro, Jess; Mallory, Stewart A; Chang, Yuancheng; Gaillard, Nicolas

    2013-01-01

    In this work, we show that laser induced breakdown spectroscopy (LIBS) with a nanosecond pulse laser can be used to measure the copper and sodium content of CuIn(0.7)Ga(0.3)Se(2) (CIGS) thin film solar cells on molybdenum. This method has four significant advantages over methods currently being employed: the method is inexpensive, measurements can be taken in times on the order of one second, without high vacuum, and at distances up to 5 meters or more. The final two points allow for in-line monitoring of device fabrication in laboratory or industrial environments. Specifically, we report a linear relationship between the copper and sodium spectral lines from LIBS and the atomic fraction of copper and sodium measured via secondary ion mass spectroscopy (SIMS), discuss the ablation process of this material with a nanosecond pulse laser compared to shorter pulse duration lasers, and examine the depth resolution of nanosecond pulse LIBS.

  18. Modeling and simulation of CuIn1-xGaxSe2 based thin film solar cell

    Science.gov (United States)

    Kumari, S.; Singh, P.; Gautam, R.; Verma, A. S.

    2014-04-01

    In this work, CIGS (Copper Indium Gallium Diselenide) based solar cell structure has been simulated. We have been calculated short circuit current, open circuit voltage and efficiency of the cell. The thickness of the absorption layer is varied from 400 to 3000 nm, keeping the thickness of other layers unchanged. The effect of absorption layer thickness over cell performance has been analyzed and found that the efficiency increases upto 22% until the thickness of the absorption layer reaches around 2000 nm.

  19. Investigations into alterntive substrate, absorber, and buffer layer processing for Cu(In,Ga)Se{sub 2}-based solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Tuttle, J.R.; Berens, T.A.; Keane, J. [National Renewable Energy Lab., Golden, CO (United States)] [and others

    1996-05-01

    High-performance Cu(In,Ga)Se{sub 2}(CIGS)-based solar cells are presently fabricated within a narrow range of processing options. In this contribution, alternative substrate, absorber, and buffer layer processing is considered. Cell performance varies considerably when alternative substrates are employed. These variations are narrowed with the addition of Na via a Na{sub 2}S compound. Sputtered and electrodeposited CIGS precursors and completed absorbers show promise as alternatives to evaporation. A recrystallization process is required to improve their quality. (In,Ga){sub y}Se buffer layers contribute to cell performance above 10. Further improvements in these alternatives will lead to combined cell performance greater than 10% in the near term.

  20. Dataset demonstrating the modeling of a high performance Cu(In,Ga)Se2 absorber based thin film photovoltaic cell.

    Science.gov (United States)

    Asaduzzaman, Md; Bahar, Ali Newaz; Bhuiyan, Mohammad Maksudur Rahman

    2017-04-01

    The physical data of the semiconductor materials used in the design of a CIGS absorber based thin film photovoltaic cell have been presented in this data article. Besides, the values of the contact parameter and operating conditions of the cell have been reported. Furthermore, by conducting the simulation with data corresponding to the device structure: soda-lime glass (SLG) substrate/Mo back-contact/CIGS absorber/CdS buffer/intrinsic ZnO/Al-doped ZnO window/Al-grid front-contact, the solar cell performance parameters such as open circuit voltage [Formula: see text], short circuit current density [Formula: see text], fill factor [Formula: see text], efficiency [Formula: see text], and collection efficiency [Formula: see text] have been analyzed.

  1. Evaluación de la fractura por fatiga del cigüeñal de un motor Diesel. // Evaluation of the crank shaft fatigue failure of a boat diesel engine.

    Directory of Open Access Journals (Sweden)

    R. A. Goytisolo Espinosa

    2005-05-01

    Full Text Available En el Trabajo se presentan los resultados de una investigación realizada por el colectivo de Mecánica Aplicada de laFacultad de Ingeniería Mecánica de La Universidad de Cienfuegos, con vistas a esclarecer la causa de la fractura delcigüeñal de uno de los motores de la Moto Nave “Mar del Sur” de le Empresa EQUITALL.La investigación del material del cigüeñal arrojó que se trata de acero 30. Los cálculos realizados demostraron, que lacapacidad resistente de este acero es insuficiente para soportar las tensiones que se desarrollan en el codo de salida delcigüeñal y los factores de seguridad a la fatiga en algunos de los puntos mas críticos del cachete, por donde se produjo lafractura, dan inferiores a la unidad y la aplicación de la Mecánica de la Fractura Subcrítica, confirmó que la Vida Útil delárbol con dicho material, es muy limitada.Palabras claves: Cigüeñal diesel, fractura por fatiga, mecánica de la fractura subcrítica.__________________________________________________________________________Abstract.This research paper shows the results of an investigation carried out by the Applied Mechanics staff of the MechanicalEngineering faculty of the Cienfuegos University. It was developed in order to determine the crankshaft failure causes ofengines of a boat diesel engine.The crankshaft material investigation showed that it was steel grade 30. The calculations showed that the steel resistancecapacity is not enough to support the stresses produced in the crankshaft output elbow. The fatigue security factors in someof the most critical areas of the cheek, where the failure took place, are lower than unity. The subcritical fracture mechanicsapplication confirmed that the shaft working life is quite limited with this steel.Key words: Diesel crankshaft, fatigue fracture, subcritical fracture mechanics.

  2. CuIn{sub 1-x}Ga{sub x}Se{sub 2}-based solar cells prepared from low-cost precursors

    Energy Technology Data Exchange (ETDEWEB)

    Calixto, M.E; Sebastian, P. J; M, Pattabi; Mathew, X; McClure, J. C [CIE-UNAM, Temixco, Morelos (Mexico)

    2000-07-01

    We report the characterization results obtained for the one step electrodeposited CuInSe{sub 2} (CIS) thin films and photovoltaic structures based on CIS and CuIn{sub 1-x}Ga{sub x}Se{sub 2} (CIGS). CIS thin films were deposited on Mo coated glass substrates, varying the deposition conditions. During the initial stages of deposition process the chemical concentration of the CIS films is rich in Cu an Se. But, after a few minutes, the concentration profile becomes constant through out the rest of the deposition process and at the end of the deposition process the film becomes In rich. The samples were analyzed using the ICP (Inductive Coupled Plasma), EDAX (Energy Dispersive Analysis by X-rays), AES (Auger Electron Spectroscopy), XRD (X-Ray Diffraction) and SEM (Scanning Electron Microscopy) techniques. The photovoltaic structures based on electrodeposited CIS and CIGS did the solar conversion with efficiency of the order of 10%. [Spanish] Informamos sobre los resultados de caracterizacion obtenidos de electrodeposicion en un solo paso de peliculas delgadas de CuInSe{sub 2} (CIS) y estructuras fotovoltaicas basadas en CIS y CuInxGal-xSe2(CIGS). Las peliculas delgadas de CIS se depositaron sobre substratos de vidrio recubiertos de Mo, variando las condiciones de deposicion. Durante las etapas iniciales del proceso de deposicion la concentracion de las peliculas de CIS es rica en Cu y Se pero despues de unos cuantos minutos el perfil de concentracion se vuelve constante a durante todo el resto de proceso de deposicion y al final del proceso de deposicion la pelicula se convierte rica en In. Las muestras se analizaron ICP (plasma acoplado inductivo) EDAX (analisis de dispersion de energia por rayos X) AES (espectroscopia electronica Auger) XRD (difraccion de rayos X) y SEM (microscopia de barrido electronico). Las estructuras fotovoltaicas basados en CIS electrodepositado y CIGS hicieron la conversion solar con eficiencias de alrededor del 10%.

  3. New Materials for Chalcogenide Based Solar Cells

    Science.gov (United States)

    Tosun, Banu Selin

    Thin film solar cells based on copper indium gallium diselenide (CIGS) have achieved efficiencies exceeding 20 %. The p-n junction in these solar cells is formed between a p-type CIGS absorber layer and a composite n-type film that consists of a 50-100 nm thin n-type CdS followed by a 50-200 nm thin n-type ZnO. This dissertation focuses on developing materials for replacing CdS and ZnO films to improve the damp-heat stability of the solar cells and for minimizing the use of Cd. Specifically, I demonstrate a new CIGS solar cell with better damp heat stability wherein the ZnO layer is replaced with SnO2. The efficiency of solar cells made with SnO2 decreased less than 5 % after 120 hours at 85 °C and 85 % relative humidity while the efficiency of solar cells made with ZnO declined by more than 70 %. Moreover, I showed that a SnO2 film deposited on top of completed CIGS solar cells significantly increased the device lifetime by forming a barrier against water diffusion. Semicrystalline SnO2 films deposited at room temperature had nanocrystals embedded in an amorphous matrix, which resulted in films without grain boundaries. These films exhibited better damp-heat stability than ZnO and crystalline SnO2 films deposited at higher temperature and this difference is attributed to the lack of grain boundary water diffusion. In addition, I studied CBD of Zn1-xCdxS from aqueous solutions of thiourea, ethylenediaminetetraacetic acid and zinc and cadmium sulfate. I demonstrated that films with varying composition (x) can be deposited through CBD and studied the structure and composition variation along the films' thickness. However, this traditional chemical bath deposition (CBD) approach heats the entire solution and wastes most of the chemicals by homogenous particle formation. To overcome this problem, I designed and developed a continuous-flow CBD approach to utilize the chemicals efficiently and to eliminate homogenous particle formation. Only the substrate is heated to

  4. Improvement of Film Quality in CuInSe2 Thin Films Fabricated by a Non-Vacuum, Nanoparticle-Based Approach

    Science.gov (United States)

    Zhang, Yiwen; Ito, Manabu; Tamura, Tomoaki; Yamada, Akira; Konagai, Makoto

    2011-04-01

    To improve the quality of CuInSe2 (CIS) thin films fabricated by a non-vacuum, nanoparticle-based approach, in this study, two categories of nanoparticles, Cu (InGa) Se2 (CIGS) nanoparticles and copper selenide (Cu-Se) with indium selenide (In-Se) nanoparticles are investigated. It is found that the Cu-Se with In-Se nanoparticles show a higher crystallization velocity than CIGS nanoparticles. The films obtained from Cu-Se with In-Se nanoparticles exhibit higher crystallinity with a larger grain size. Thiourea is applied as a sintering additive during the selenization process. It is clarified that the addition of thiourea is very effective for grain growth and the fabrication of a dense CIS layer. The cell performance is measured under Air Mass 1.5 irradiation. The efficiency of the solar cell, fabricated using Cu-Se, In-Se nanoparticles with thiourea, is 2.15%, higher than that of the solar cell fabricated using CIGS nanoparticles, which is 0.28%.

  5. Fundamental Materials Research and Advanced Process Development for Thin-Film CIS-Based Photovoltaics: Final Technical Report, 2 October 2001 - 30 September 2005

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, T. J.; Li, S. S.; Crisalle, O. D.; Craciun, V.

    2006-09-01

    The objectives for this thin-film copper-indium-diselenide (CIS) solar cell project cover the following areas: Develop and characterize buffer layers for CIS-based solar cell; grow and characterize chemical-bath deposition of Znx Cd1-xS buffer layers grown on CIGS absorbers; study effects of buffer-layer processing on CIGS thin films characterized by the dual-beam optical modulation technique; grow epitaxial CuInSe2 at high temperature; study the defect structure of CGS by photoluminescence spectroscopy; investigate deep-level defects in Cu(In,Ga)Se2 solar cells by deep-level transient spectroscopy; conduct thermodynamic modeling of the isothermal 500 C section of the Cu-In-Se system using a defect model; form alpha-CuInSe2 by rapid thermal processing of a stacked binary compound bilayer; investigate pulsed non-melt laser annealing on the film properties and performance of Cu(In,Ga)Se2 solar cells; and conduct device modeling and simulation of CIGS solar cells.

  6. EffiCiency and Safety of an eLectronic cigAreTte (ECLAT) as Tobacco Cigarettes Substitute: A Prospective 12-Month Randomized Control Design Study

    OpenAIRE

    Pasquale Caponnetto; Davide Campagna; Fabio Cibella; Morjaria, Jaymin B; Massimo Caruso; Cristina Russo; Riccardo Polosa

    2013-01-01

    BACKGROUND: Electronic cigarettes (e-cigarettes) are becoming increasingly popular with smokers worldwide. Users report buying them to help quit smoking, to reduce cigarette consumption, to relieve tobacco withdrawal symptoms, and to continue having a 'smoking' experience, but with reduced health risks. Research on e-cigarettes is urgently needed in order to ensure that the decisions of regulators, healthcare providers and consumers are based on science. Methods ECLAT is a prospective 12-mont...

  7. Cu(In,Ga)(Se,S)2 solar cell research in Solar Frontier: Progress and current status

    Science.gov (United States)

    Kato, Takuya

    2017-04-01

    As the largest manufacturer of Cu(In,Ga)(Se,S)2 (CIGS) thin-film photovoltaic modules with more than 1 GW/year production volume, Solar Frontier K.K. has continuously improved module performance and small-area cell efficiencies in the laboratory. Because of our low-cost and environmentally-friendly process, Solar Frontier’s CIGS is a promising technology for the mass production of photovoltaic modules to fill ever-increasing demand. Recently we have achieved certified efficiencies of 22.3 and 22.0% on CdS-buffered and Cd-free buffered small-area cells, respectively, as well as 18.6% on a Cd-free mini-module. In this paper, a review of our CIGS technology and recent progress on the development of the module and the small-area cell is presented.

  8. Encapsulated Somatic Embryos and Zygotic Embryos for Obtaining Artificial Seeds of Rauli-Beech (Nothofagus alpina (Poepp. & Endl. Oerst. Encapsulado de Embriones Somáticos y Embriones Cigóticos para Obtención de Semillas Artificiales de Raulí (Nothofagus alpina (Poepp. & Endl. Oerst.

    Directory of Open Access Journals (Sweden)

    Priscila Cartes R

    2009-03-01

    Full Text Available Somatic and zygotic embryos from mature seeds of rauli-beech, Nothofagus alpina (Poepp. & Endl. Oerst., were encapsulated in different artificial endosperms in order to generate a cover that fulfills the function of nourishment and protection of the embryos, facilitating their later germination. The content of sodium alginate varied by 4%, 3%, and 2%, as did the immersion time in calcium chloride (CaCl2, which acts as complexing agent. The artificial endosperm components of the Murashige and Skoog medium (MS were added, supplemented with 0.5 mg L-1 indolacetic acid (IAA, 0.5 mg L-1 naphthaleneacetic acid (NAA, 2 mg L-1 6-benzylaminopurine (BAP and 30 g L-1 sucrose. The germinative behaviors of encapsulated somatic and zygotic embryos were evaluated after 4 wk. Comparing the percentages of germination reached by encapsulated somatic and zygotic embryos it was observed that they had similar germinative behavior according to the type of encapsulation applied. However, zygotic embryos substantially exceeded the germination levels reached by somatic embryos, 100% vs. 45% respectively.Embriones somáticos y cigóticos provenientes de semillas maduras de raulí, Nothofagus alpina (Poepp. & Endl. Oerst., se encapsularon en diferentes endospermas sintéticos con el fin de generar una cubierta que cumpla la función de nutrir y proteger al embrión para facilitar su posterior germinación. Se varió el contenido de alginato de sodio al 4%, 3% y 2% y el tiempo de inmersión en cloruro de calcio (CaCl2, el que actúa como agente acomplejante. Además, a la matriz artificial se adicionaron componentes del medio Murashige y Skoog (MS suplementado con: 0,5 mg L-1 de indolacetic acid (IAA, 0,5 mg L-1 de ácido naftalenacético (NAA, 2 mg L-1 de 6-bencilaminopurina (BAP y 30 gL-1 de sacarosa. Al cabo de 4 semanas el porcentaje de germinación de los embriones somáticos y cigóticos encapsulados tuvieron similar comportamiento germinativo según el tipo de

  9. Increasing solar cell efficiencies based on Cu(In,Ga)Se{sub 2} after a specific chemical and oxidant treatment

    Energy Technology Data Exchange (ETDEWEB)

    Canava, B.; Etcheberry, A. [Institut de Reactivite, Electrochimie et Microporosites (UMR CNRS 8637), Universite de Versailles, 45 Avenue des Etats-Unis, 78035 Versailles (France); Roussel, O.; Guillemoles, J.F.; Lincot, D. [Institut de Recherche et de Developpement sur l' Energie Photovoltaique (UMR 7174 CNRS-ENSCP-EDF - EDF R and D), Centre de Chatou, 6 quai Watier, 78400 Chatou (France)

    2006-09-15

    Oxidative etching treatments based on bromine water mixtures have been studied on polycrystalline thin films of Cu(In,Ga)Se{sub 2}. This treatment enables preparation of planar, smooth and specular surfaces whose chemical properties are well defined, despite the small thickness of the layers ({approx}2 {mu}m). After device completion, the electronic properties (I-V curve, spectral response) were studied and correlated to device performances. Theses conditions allow to re-engineer damaged or aged surfaces of CIGS and to recover high photovoltaic performances. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  10. Numerical Analysis of Copper-Indium-Gallium-Diselenide-Based Solar Cells by SCAPS-1D

    Directory of Open Access Journals (Sweden)

    S. Ouédraogo

    2013-01-01

    Full Text Available We used a one-dimensional simulation program Solar Cell Capacitance Simulator in 1 Dimension (SCAPS-1D to investigate Copper-Indium-Gallium-Diselenide- (CIGS- based solar cells properties. Starting with a conventional ZnO-B/i-ZnO/CdS/CIGS structure, we simulated the parameters of current-voltage characteristics and showed how the absorber layer thickness, hole density, and band gap influence the short-circuit current density (Jsc, open-circuit voltage (Voc, fill factor (FF, and efficiency of solar cell. Our simulation results showed that all electrical parameters are greatly affected by the absorber thickness (w below 1000 nm, due to the increase of back-contact recombination and very poor absorption. Increasing hole density (p or absorber band gap (Eg improves Voc and leads to high efficiency, which equals value of 16.1% when p = 1016 cm−3 and Eg=1.2 eV. In order to reduce back-contact recombination, the effect of a very thin layer with high band gap inserted near the back contact and acting as electrons reflector, the so-called back-electron reflector (EBR, has been investigated. The performances of the solar cells are significantly improved, when ultrathin absorbers (w < 500 nm are used; the corresponding gain of Jsc due to the EBR is 3 mA/cm2. Our results are in good agreement with those reported in the literature from experiments.

  11. Alternative window schemes for CuInSe{sub 2}-based solar cells. Annual report, 1 November 1995--31 October 1996

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, L.C. [Washington State Univ., Richland, WA (United States). Electronic Materials Lab.

    1997-10-01

    The objectives of this program are to develop alternate heterojunction partner layers (buffer layers) for high efficiency CuInSe{sub 2}-based thin-film solar cells, and improve the understanding of how these layers and the details of processing affect cell performance. Investigations have primarily involved three tasks: (1) MOCVD growth of non-cadmium containing buffer layers; (2) optimized processing of buffer layers for high efficiency solar cells; and (3) electrical and physical characterization of layers and devices. Investigations of alternative buffer layers emphasized studies of ZnO grown by MOCVD. Using CIS substrates obtained form Siemens for process development, it was determined that growth procedures that resulted in good results with Siemens CIS (non-sulfur containing material) substrates also worked well with NREL CIGS material. A two step process was developed for growing highly resistive ZnO buffer layers (i-ZnO). In particular, after growing 100 to 150 {angstrom} of ZnO at 250 C, an additional 600 {angstrom} to 800 {angstrom} were grown at 100 C. Collaboration with NREL resulted in a n-ZnO/i-ZnO/CIGS cell which was determined to have a total area efficiency of 12.7%, and an active area efficiency greater than 13%. After growing i-ZnO with the two-step process onto NREL CIGS material, the i-ZnO/CIGS film structure was sent to NREL for deposition of a TCO, namely, conducting ZnO (n-ZnO). Collector grids and a MgF{sub 2} AR coating were also deposited at NREL. Low level efforts were devoted to studies of ZnSe and InSe buffer layers. A total area efficiency of 9.5% was achieved for a completed ZnSe/CIS cell making use of a RF sputtered ZnO for a TCO. Investigations of In{sub x}Se{sub y} (InSe) buffer layers were also initiated this past year.

  12. Incorporation of Cu in Cu(In,Ga)Se{sub 2}-based thin-film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Yong-Duck; Cho, Dae-Hyung; Han, Won-Seok; Park, Nae-Man; Lee, Kyu-Seok; Kim, Je-Ha [Electronics and Telecommunications Research Institute, Daejeon (Korea, Republic of)

    2010-12-15

    We have fabricated Cu(In,Ga)Se{sub 2} (CIGS)-based thin-film solar cells by using a cluster-type deposition system. The system is composed of a DC sputter for the Mo back electrode, a co-evaporator for the CIGS absorption layer, and a RF sputter for the ZnO and the transparent-conductive-oxide (TCO) window layers. The deposition of the CdS buffer layer was performed separately. Two solar cells with an effective area of 0.47 cm{sup 2} were fabricated using different processes. One cell, which was prepared with a 1-step process, had a larger atomic concentration of In-Ga than of Cu in the absorption layer and showed a conversion efficiency of 11.1%. The other prepared with a 3-step process had nearly the same In-Ga and Cu concentrations and showed a conversion efficiency of 15.5%. We discuss the incorporation of Cu in the two types of thin-film solar cells.

  13. Chemical synthesis of Cd-free wide band gap materials for solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Sankapal, B.R.; Sartale, S.D.; Ennaoui, A. [Hahn-Meitner-Institut, Berlin (Germany). Department of Solar Energy Research; Lokhande, C.D. [Shivaji University, Kolhapur (India). Department of Physics

    2004-07-01

    Chemical methods are nowadays very attractive, since they are relatively simple, low cost and convenient for larger area deposition of thin films. In this paper, we outline our work related to the synthesis and characterization of some wide band gap semiconducting material thin films prepared by using solution methods, namely, chemical bath deposition and successive ionic layer adsorption and reaction (SILAR). The optimum preparative parameters are given and respective structural, surface morphological, compositional, optical, and electrical properties are described. Some materials we used in solar cells as buffer layers and achieved remarkable results, which are summarized. (author)

  14. Performance and Loss Analyses of High-Efficiency Chemical Bath Deposition (CBD)-ZnS/Cu(In1-xGax)Se2 Thin-Film Solar Cells

    Science.gov (United States)

    Pudov, Alexei; Sites, James; Nakada, Tokio

    2002-06-01

    Chemically deposited ZnS has been investigated as a buffer layer alternative to cadmium sulfide (CdS) in polycrystalline thin-film Cu(In1-xGax)Se2 (CIGS) solar cells. Cells with efficiency of up to 18.1% based on chemical bath deposition (CBD)-ZnS{\\slash}CIGS heterostructures have been fabricated. This paper presents the performance and loss analyses of these cells based on the current-voltage (J-V) and spectral response curves, as well as comparisons with high efficiency CBD-CdS/CIGS and crystalline silicon counterparts. The CBD-ZnS/CIGS devices have effectively reached the efficiency of the current record CBD-CdS/CIGS cell. The effects of the superior current of the CBD-ZnS/CIGS cell and the superior junction quality of the CBD-CdS/CIGS cell on overall performance nearly cancel each other.

  15. Plastic Surgeons Urge Giving Up E-Cigs Before Procedure

    Science.gov (United States)

    ... HealthDay News) -- Plastic surgery patients should avoid smoking e-cigarettes for at least four weeks before their procedures, ... reasonable to advise plastic surgery candidates to cease e-cigarette use," said Dr. Peter Taub,, of Mount Sinai ...

  16. CIG Northern US Rockies and Pacific Northwest Statistical Downscaling

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The goal of this project was to (1) develop consistent historical and future downscaled climate and hydrologic data and projections using the same methodology for...

  17. Spatial atmospheric ALD of functional layers for CIGS Solar Cells

    NARCIS (Netherlands)

    Illiberi, A.; Frijters, C.; Balder, J.E.; Poodt, P.W.G.; Roozeboom, F.

    2015-01-01

    Spatial Atmosperic Atomic Layer Depositon combines the advantages of temporal ALD, i.e. excellent control of film composition and uniformity over large area substrates, with high growth rages (up tot nm/s). In this paper we present a short overview of our research acctivity carried out on S-ALD of f

  18. Base

    DEFF Research Database (Denmark)

    Hjulmand, Lise-Lotte; Johansson, Christer

    2004-01-01

    BASE - Engelsk basisgrammatik er resultatet af Lise-Lotte Hjulmands grundige bearbejdning og omfattende revidering af Christer Johanssons Engelska basgrammatik. Grammatikken adskiller sig fra det svenske forlæg på en lang række punkter. Den er bl.a. tilpasset til et dansk publikum og det danske...

  19. Prohibition of e-cigarettes in the US: Are prohibitions where alcohol is consumed related to lower alcohol consumption?

    Science.gov (United States)

    Hershberger, Alexandra R; Karyadi, Kenny A; Cyders, Melissa A

    2016-12-01

    Recently, research has suggested negative consequences related to electronic cigarette (e-cig) use, including the increased risk for alcohol use and abuse. Previous work found that cigarette smoking ban legislation lowered overall smoking and alcohol use rates; however, researchers have not yet examined the potential effects of prohibiting e-cig use. The present study surveyed 617 individuals from a community-based online sample in the US (mean age = 33.33, SD = 10.50, 54.7 per cent female) who reported their smoking/e-cig use status, alcohol consumption, and the presence of e-cig prohibitions where they consume alcohol. E-cig prohibition was associated with a lower likelihood of being an e-cig user (OR = 0.12, p e-cigs) (OR = 0.07, p e-cigs were prohibited. Findings are an initial step in this line of research and suggest important future work examining implications of e-cig prohibition recommendations and policy.

  20. Crystallization Behavior of Solution-Processed CIGSe Thin Film Semiconductor by Stepwise Annealing Process.

    Science.gov (United States)

    Park, Mi Sun; Sung, Shi-Joon; Kim, Dae-Hwan

    2015-03-01

    CuIn(x)Ga1-xSe2 (CIGS) thin films were prepared by a solution-based CuInGa (CIG) precursor- selenization process. First, we investigated the effect of selenization temperature on the formation of polycrystalline CIGS and grain growth. The CIG precursor films were selenized using a two-step process to investigate the reaction of Se and CIG precursors during the formation of CIGS thin films. Depending on the temperature in the 1st step of the selenization process, the CIG precursor forms a different intermediate phase between the single phase to ternary phase such as Cu, Se, CuSe, InSe, and CuInSe2. In addition, the intermediate phase exerts a significant influence on the final phase obtained after the 2nd step of the selenization process, particularly with regard to characteristics such as polycrystalline structure and grain growth in the CIGS films. The photoelectron conversion efficiency of devices prepared using CIGS thin films was approximately 1.59-2.75%.

  1. Copper zinc tin sulfide-based thin film solar cells

    CERN Document Server

    Ito, Kentaro

    2014-01-01

    Beginning with an overview and historical background of Copper Zinc Tin Sulphide (CZTS) technology, subsequent chapters cover properties of CZTS thin films, different preparation methods of CZTS thin films, a comparative study of CZTS and CIGS solar cell, computational approach, and future applications of CZTS thin film solar modules to both ground-mount and rooftop installation. The semiconducting compound (CZTS) is made up earth-abundant, low-cost and non-toxic elements, which make it an ideal candidate to replace Cu(In,Ga)Se2 (CIGS) and CdTe solar cells which face material scarcity and tox

  2. Investigation of Non-Vacuum Deposition Techniques in Fabrication of Chalcogenide-Based Solar Cell Absorbers

    KAUST Repository

    Alsaggaf, Ahmed

    2015-07-01

    The environmental challenges are increasing, and so is the need for renewable energy. For photovoltaic applications, thin film Cu(In,Ga)(S,Se)2 (CIGS) and CuIn(S,Se)2 (CIS) solar cells are attractive with conversion efficiencies of more than 20%. However, the high-efficiency cells are fabricated using vacuum technologies such as sputtering or thermal co-evaporation, which are very costly and unfeasible at industrial level. The fabrication involves the uses of highly toxic gases such as H2Se, adding complexity to the fabrication process. The work described here focused on non-vacuum deposition methods such as printing. Special attention has been given to printing designed in a moving Roll-to-Roll (R2R) fashion. The results show potential of such technology to replace the vacuum processes. Conversion efficiencies for such non-vacuum deposition of Cu(In,Ga)(S,Se)2 solar cells have exceeded 15% using hazardous chemicals such as hydrazine, which is unsuitable for industrial scale up. In an effort to simplify the process, non-toxic suspensions of Cu(In,Ga)S2 molecular-based precursors achieved efficiencies of ~7-15%. Attempts to further simplify the selenization step, deposition of CuIn(S,Se)2 particulate solutions without the Ga doping and non-toxic suspensions of Cu(In,Ga)Se2 quaternary precursors achieved efficiencies (~1-8%). The contribution of this research was to provide a new method to monitor printed structures through spectral-domain optical coherence tomography SD-OCT in a moving fashion simulating R2R process design at speeds up to 1.05 m/min. The research clarified morphological and compositional impacts of Nd:YAG laser heat-treatment on Cu(In,Ga)Se2 absorber layer to simplify the annealing step in non-vacuum environment compatible to R2R. Finally, the research further simplified development methods for CIGS solar cells based on suspensions of quaternary Cu(In,Ga)Se2 precursors and ternary CuInS2 precursors. The methods consisted of post deposition reactive

  3. Modeling of Thin Film Solar Photovoltaic Based on Zno/Sns Oxide-Absorber Substrate Configuration

    Directory of Open Access Journals (Sweden)

    Anupam Verma

    2014-06-01

    Full Text Available Due to increasing awareness for using clean energy and therefore greater demand for relying more on the renewable sources which solar photovoltaic are part of because they pose very little or no threat to the environment comparatively, there is growing pressure for reducing electricity generation costs from solar photovoltaic (PV modules. Hence there is need for alternative new light absorbing materials that can provide conversion efficiencies which would be comparable to the current technologies based on crystalline silicon and CdTe or CIGS thin films at lower manufacturing costs and therefore providing cost effective solutions. In this paper we have evaluated the tin based absorber material (based on tin monosulfide; SnS as the next generation of Photovoltaic cells that can provide the desired performance in the long term. Therefore it explores the potential use of tin mono-sulfide as photovoltaic material for conversion of light into electricity. Zinc Oxide (ZnO thin films have been recognized as good candidates in photovoltaic devices acting as wide-band gap window layer. The results are presented through the numerical analysis done by AMPD-1D simulator tool to explore the possibility of using thin film and stable ZnO/SnS solar photovoltaic device with aim to achieve comparable conversion efficiencies.

  4. Electron accelerator-based production of molybdenum-99: Bremsstrahlung and photoneutron generation from molybdenum vs. tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Tsechanski, A. [Ben-Gurion University of the Negev, Department of Nuclear Engineering, P.O. Box 653, Beer-Sheva 84105 (Israel); Bielajew, A.F. [Department of Nuclear Engineering and Radiological Sciences, The University of Michigan, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109 (United States); Archambault, J.P.; Mainegra-Hing, E. [National Research Council of Canada, Ionizing Radiation Standards Laboratory, Ottawa, ON K1A 0R6 (Canada)

    2016-01-01

    A new “one-stage” approach for production of {sup 99}Mo and other radioisotopes by means of an electron linear accelerator is described. It is based on using a molybdenum target both as a bremsstrahlung converter and as a radioisotope producing target for the production of {sup 99}Mo via the photoneutron reaction {sup 100}Mo(γ,n){sup 99}Mo. Bremsstrahlung characteristics, such as bremsstrahlung efficiency, angular distribution, and energy deposition for molybdenum targets were obtained by means of the EGSnrc Monte Carlo simulation code system. As a result of our simulations, it is concluded that a 60 MeV electron beam incident on a thick Mo target will have greater bremsstrahlung efficiency than the same thickness (in units of r{sub 0}) W target, for target thickness z > 1.84r{sub 0}, where r{sub 0} is the electron range. A 50 MeV electron beam incident on a Mo target will result in greater bremsstrahlung efficiency than the same thickness W target (in units of r{sub 0}) for target thickness case: z ⩾ 2.0r{sub 0}. It is shown for the one-stage approach with thicknesses of (1.84–2.0)r{sub 0}, that the {sup 99}Mo-production bremsstrahlung efficiency of a molybdenum target is greater by ∼100% at 30 MeV and by ∼70% at 60 MeV compared to the values for tungsten of the same thickness (in units of the appropriate r{sub 0}) in the traditional two-stage approach (W converter and separate {sup 99}Mo producing target). This advantage of the one-stage approach arises from the fact that the bremsstrahlung produced is attenuated only once from attenuation in the molybdenum converter/target. In the traditional, two-stage approach, the bremsstrahlung generated in the W-converter/target is attenuated both in the converter in the {sup 99}Mo-producing molybdenum target. The photoneutron production yield of molybdenum and tantalum (as a substitute for tungsten) target was calculated by means of the MCNP5 transport code. On the basis of these data, the specific activity

  5. Electron accelerator-based production of molybdenum-99: Bremsstrahlung and photoneutron generation from molybdenum vs. tungsten

    Science.gov (United States)

    Tsechanski, A.; Bielajew, A. F.; Archambault, J. P.; Mainegra-Hing, E.

    2016-01-01

    A new "one-stage" approach for production of 99Mo and other radioisotopes by means of an electron linear accelerator is described. It is based on using a molybdenum target both as a bremsstrahlung converter and as a radioisotope producing target for the production of 99Mo via the photoneutron reaction 100Mo(γ,n)99Mo. Bremsstrahlung characteristics, such as bremsstrahlung efficiency, angular distribution, and energy deposition for molybdenum targets were obtained by means of the EGSnrc Monte Carlo simulation code system. As a result of our simulations, it is concluded that a 60 MeV electron beam incident on a thick Mo target will have greater bremsstrahlung efficiency than the same thickness (in units of r0) W target, for target thickness z > 1.84r0, where r0 is the electron range. A 50 MeV electron beam incident on a Mo target will result in greater bremsstrahlung efficiency than the same thickness W target (in units of r0) for target thickness case: z ⩾ 2.0r0. It is shown for the one-stage approach with thicknesses of (1.84-2.0)r0, that the 99Mo-production bremsstrahlung efficiency of a molybdenum target is greater by ∼100% at 30 MeV and by ∼70% at 60 MeV compared to the values for tungsten of the same thickness (in units of the appropriate r0) in the traditional two-stage approach (W converter and separate 99Mo producing target). This advantage of the one-stage approach arises from the fact that the bremsstrahlung produced is attenuated only once from attenuation in the molybdenum converter/target. In the traditional, two-stage approach, the bremsstrahlung generated in the W-converter/target is attenuated both in the converter in the 99Mo-producing molybdenum target. The photoneutron production yield of molybdenum and tantalum (as a substitute for tungsten) target was calculated by means of the MCNP5 transport code. On the basis of these data, the specific activity for the one-stage approach of three enriched 100Mo-targets of a 2 cm diameter and

  6. Solar Cells Based on Low-dimensional Nanocomposite Structures

    Directory of Open Access Journals (Sweden)

    S.L. Khrypko

    2016-12-01

    Full Text Available Converting solar energy into electric energy with using of solar batteries is a major task for developers and research teams. In this article we will look at the development of different generations of solar batteries for to create a nanocomposite structure. Production of solar batteries has gone through some steps, taking into account technological and economic aspects that have been associated with improved of their parameters. Thus the first generations of solar batteries have been based on the single-crystal silicon substrates (с-Si. The use of polycrystalline silicon and multi- crystalline allowed lower costs of modules, but due to the efficiency of solar energy conversion. The solar batteries of the second generation were based on thin-film technology, in which use different materials: silicon films based on amorphous silicon (a-Si, a film based on cadmium telluride (CdTe and film selenide copper-indium-gallium (CuInGaSe2, or CIGS. The use of such technology has allowed increasing the coefficient of performance (COP solar cell with a significant reduction in costs. The solar batteries of third-generation based on nanotechnology, nanocrystals and nano-sized clusters of semiconductors. The creation of such solar cells requires availability of a low-dimensional composite structure. Low-dimensional nanocomposite structures that are constructed on quantum dots and nano-porous materials have new modified optoelectronic properties. They can be used in solar elements, where absorption bands can be optimally adapted to the wavelength of radiation light. These structures could theoretically can lead to increased efficiency of solar energy conversion more than 65%, which can double practically current efficiency of solar batteries.

  7. Inkjet printed Cu(In,Ga)S2 nanoparticles for low-cost solar cells

    Science.gov (United States)

    Barbé, Jérémy; Eid, Jessica; Ahlswede, Erik; Spiering, Stefanie; Powalla, Michael; Agrawal, Rakesh; Del Gobbo, Silvano

    2016-12-01

    Cu(In,Ga)Se2 (CIGSe) thin film solar cells were fabricated by direct inkjet printing of Cu(In,Ga)S2 (CIGS) nanoparticles followed by rapid thermal annealing under selenium vapor. Inkjet printing is a low-cost, low-waste, and flexible patterning method which can be used for deposition of solution-based or nanoparticle-based CIGS films with high throughput. XRD and Raman spectra indicate that no secondary phase is formed in the as-deposited CIGS film since quaternary chalcopyrite nanoparticles are used as the base solution for printing. Besides, CIGSe films with various Cu/(In + Ga) ratios could be obtained by finely tuning the composition of CIGS nanoparticles contained in the ink, which was found to strongly influence the devices performance and film morphology. To date, this is the first successful fabrication of a solar device by inkjet printing of CIGS nanoparticles.

  8. Inkjet printed Cu(In,Ga)S2 nanoparticles for low-cost solar cells

    KAUST Repository

    Barbe, Jeremy

    2016-12-13

    Cu(In,Ga)Se2 (CIGSe) thin film solar cells were fabricated by direct inkjet printing of Cu(In,Ga)S2 (CIGS) nanoparticles followed by rapid thermal annealing under selenium vapor. Inkjet printing is a low-cost, low-waste, and flexible patterning method which can be used for deposition of solution-based or nanoparticle-based CIGS films with high throughput. XRD and Raman spectra indicate that no secondary phase is formed in the as-deposited CIGS film since quaternary chalcopyrite nanoparticles are used as the base solution for printing. Besides, CIGSe films with various Cu/(In + Ga) ratios could be obtained by finely tuning the composition of CIGS nanoparticles contained in the ink, which was found to strongly influence the devices performance and film morphology. To date, this is the first successful fabrication of a solar device by inkjet printing of CIGS nanoparticles.

  9. Progress in Thin Film Solar Cells Based on Cu2ZnSnS4

    Directory of Open Access Journals (Sweden)

    Hongxia Wang

    2011-01-01

    Full Text Available The research in thin film solar cells has been dominated by light absorber materials based on CdTe and Cu(In,GaSe2 (CIGS in the last several decades. The concerns of environment impact of cadmium and the limited availability of indium in those materials have driven the research towards developing new substitute light absorbers made from earth abundant, environment benign materials. Cu2ZnSnS4 (CZTS semiconductor material has emerged as one of the most promising candidates for this aim and has attracted considerable interest recently. Significant progress in this relatively new research area has been achieved in the last three years. Over 130 papers on CZTS have been published since 2007, and the majority of them are on the preparation of CZTS thin films by different methods. This paper, will review the wide range of techniques that have been used to deposit CZTS semiconductor thin films. The performance of the thin film solar cells using the CZTS material will also be discussed.

  10. Synchrotron X-Ray Characterization of Alkali Elements at Grain Boundaries in Cu(In, Ga)Se2 Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    West, Bradley; Stuckelberger, Michael; Guthrey, Harvey; Chen, Lei; Lai, Barry; Maser, Jorg; Rose, Volker; Dynes, James J.; Shafarman, William; Al-Jassim, Mowafak; Bertoni, Mariana I.

    2016-11-21

    It is well known that the addition of alkali elements such as Na and K during and after growth of Cu(In, Ga)Se2 (CIGS) has beneficial effects on the electronic properties of bulk material, improving device performance significantly. While the device level effects have been measured and reported, a direct observations of the localization of Na including its chemical nature are missing, and the impact of Na on elemental and phase segregation during CIGS growth is not fully understood. We investigate these aspects to shine light on the role of Na in CIGS solar cells with the ultimate goal of increasing their conversion efficiency. Utilizing a suite of synchrotron based x-ray characterization techniques, we discuss the challenges and advantages of these techniques for investigating segregation of main constituents of CIGS, Na distribution, chemical bonding of Na, and collection efficiency in CIGS as well as their correlations.

  11. Knowledge engineering for adverse drug event prevention: on the design and development of a uniform, contextualized and sustainable knowledge-based framework.

    Science.gov (United States)

    Koutkias, Vassilis; Kilintzis, Vassilis; Stalidis, George; Lazou, Katerina; Niès, Julie; Durand-Texte, Ludovic; McNair, Peter; Beuscart, Régis; Maglaveras, Nicos

    2012-06-01

    The primary aim of this work was the development of a uniform, contextualized and sustainable knowledge-based framework to support adverse drug event (ADE) prevention via Clinical Decision Support Systems (CDSSs). In this regard, the employed methodology involved first the systematic analysis and formalization of the knowledge sources elaborated in the scope of this work, through which an application-specific knowledge model has been defined. The entire framework architecture has been then specified and implemented by adopting Computer Interpretable Guidelines (CIGs) as the knowledge engineering formalism for its construction. The framework integrates diverse and dynamic knowledge sources in the form of rule-based ADE signals, all under a uniform Knowledge Base (KB) structure, according to the defined knowledge model. Equally important, it employs the means to contextualize the encapsulated knowledge, in order to provide appropriate support considering the specific local environment (hospital, medical department, language, etc.), as well as the mechanisms for knowledge querying, inference, sharing, and management. In this paper, we present thoroughly the establishment of the proposed knowledge framework by presenting the employed methodology and the results obtained as regards implementation, performance and validation aspects that highlight its applicability and virtue in medication safety.

  12. Buffer layer selection for CuIn1 - x Ga x Se2 based thin film solar cells

    Science.gov (United States)

    Kumari, Sarita; Singh Verma, Ajay

    2014-03-01

    In this work, device modeling and simulation studies have been carried out with a variety of buffer layers over CIGS absorption layer. The band diagram, electric field variation and I/V curves are analyzed and device performance parameters i.e. efficiency, open circuit voltage, short circuit current, quantum efficiency are calculated. The efficiency of CIGS solar cell with ZnSe buffer layer is found comparable with that of CdS layer. The highest short circuit current is found for solar cell with ZnSe buffer layer, whereas the ZnS/CIGS heterojunction provides the highest quantum efficiency in the structures considered. The device physics is discussed and the effect of thickness of buffer layers and absorption layer is studied in order to find a more efficient and stable solar cell.

  13. Totally solution-processed CuInS2 solar cells based on chloride inks: reduced metastable phases and improved current density

    Science.gov (United States)

    Dehghani, Mehdi; Behjat, Abbas; Tajabadi, Fariba; Taghavinia, Nima

    2015-03-01

    Planar superstrate CuInS2 (CIS) solar cell devices are fabricated using totally solution-processed deposition methods. These Cd-free devices are structured by FTO/TiO2/In2S3/CIS/carbon, where TiO2 and In2S3 are deposited by spray pyrolysis, and a CIS film is deposited using spin-coating followed by annealing at 250 °C. The pasted carbon layer is utilized as the anode. No further sulfurization or selenization is employed. The Cu/In ratio in the ink is found as a critical factor affecting the morphology and crystallinity of the film as well as the photovoltaic performance of the device. An optimum Cu/In = 1.05 results in large-grain films with sharp diffraction peaks and, subsequently, optimal series resistance and shunt conductance. It is also found that the chloride-based ink results in CIS films with considerably reduced metastable phases, compared to the conventional acetate-based inks. A current density of 23.6 mA cm-2 is obtained for the best devices, leading to a conversion efficiency of 4.1%.

  14. The Renner-Teller effect and Sears resonances in the ground state of the GeCH and GeCD free radicals

    Science.gov (United States)

    He, Sheng-Gui; Li, Haiyang; Smith, Tony C.; Clouthier, Dennis J.; Merer, Anthony J.

    2003-11-01

    The vibrational energy levels of the jet-cooled GeCH and GeCD radicals have been studied by a combination of laser-induced fluorescence and wavelength-resolved emission techniques. The radicals were produced in a pulsed electric discharge free jet expansion using methyltrichlorogermane and tetramethylgermane-d12 precursors. A re-examination of the weaker hot bands in the LIF spectrum has provided a more complete vibrational analysis of the upper state energy levels. The single vibronic level emission spectra obtained by pumping several bands of each isotopomer were analyzed to provide information on the low-lying ground state vibronic energy levels up to 3000 cm-1 above the zero-point level. Strong interactions occur in these molecules between vibronic levels with the same value of P, but differing by one unit of v2; such interactions were first described for NCS by Northrup and Sears [Mol. Phys. 71, 45 (1990)] and are conveniently called "Sears resonances." The spectra of GeCH were further complicated by Fermi resonances between the bending and Ge-C stretching levels. Despite these difficulties, it proved possible to analyze the data using a standard Renner-Teller model with the addition of Sears resonance coupling terms. The validity of the fitted parameters was tested using the isotope relations. The Sears resonance parameters for GeCH are much larger than those of NCS, a result of the much stronger vibronic coupling in the germanium methylidynes.

  15. Transport, Interfaces, and Modeling in Amorphous Silicon Based Solar Cells: Final Technical Report, 11 February 2002 - 30 September 2006

    Energy Technology Data Exchange (ETDEWEB)

    Schiff, E. A.

    2008-10-01

    Results for a-Si characteristics/modeling; photocarrier drift mobilities in a-Si;H, ..mu..c-Si:H, CIGS; hole-conducting polymers as p-layer for a-Si and c-Si; IR spectra of p/i and n/i interfaces in a-Si.

  16. Recovery of galium and indium from liquid crystal displays and CIGS photovailtaic modules

    NARCIS (Netherlands)

    Bisselink, R.; Steeghs, W.; Brouwer, J.G.H.

    2014-01-01

    Abstract: The increasing amount of electronics, such as consumer products and green technologies (e.g. solar PV cells) increases the demand of metals such as indium and gallium. This increasing demand together with the dependency on import of these metals drive research on recycling of waste electro

  17. Modeling and Simulation of a Dual-Junction CIGS Solar Cell Using Silvaco ATLAS

    Science.gov (United States)

    2012-12-01

    Development. 15. NUMBER OF PAGES 118 16. PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT Unclassified 18. SECURITY CLASSIFICATION OF THIS...PAGE Unclassified 19. SECURITY CLASSIFICATION OF ABSTRACT Unclassified 20. LIMITATION OF ABSTRACT UU NSN 7540–01–280–5500 Standard Form...Pulsed Laser Deposition PV Photovoltaic PVD Physical Vapor

  18. Kids Landing in ERs After Drinking Parents' E-Cig Nicotine Liquid

    Science.gov (United States)

    ... accidentally swallowed liquid nicotine used in her parents' e-cigarettes. The girl's mother had filled an empty ibuprofen ... at Oregon Health & Science University. Because nicotine in e-cigarette refill liquid is highly concentrated, it's particularly dangerous ...

  19. Nicotine in E-Cigs Can Trigger Lifelong Addiction in Kids

    Science.gov (United States)

    ... start using nicotine -- even in the form of e-cigarettes -- the harder it is for them to quit ... the U.S. Surgeon General's office, which noted that e-cigarette use rose 900 percent among U.S. high school ...

  20. Expanding thermal plasma chemical vapour deposition of ZnO:Al layers for CIGS solar cells

    NARCIS (Netherlands)

    Sharma, K.; Williams, B.L.; Mittal, A.; Knoops, H.C.M.; Kniknie, B.J.; Bakker, N.J.; Kessels, W.M.M.; Schropp, R.E.I.; Creatore, M.

    2014-01-01

    Aluminium-doped zinc oxide (ZnO:Al) grown by expanding thermal plasma chemical vapour deposition (ETP-CVD) has demonstrated excellent electrical and optical properties, which make it an attractive candidate as a transparent conductive oxide for photovoltaic applications. However, when depositing ZnO

  1. Thinning of CIGS solar cells: Part I: Chemical processing in acidic bromine solutions

    Energy Technology Data Exchange (ETDEWEB)

    Bouttemy, M.; Tran-Van, P. [Institut Lavoisier de Versailles (ILV-UMR 8180 CNRS/UVSQ), 45 av. des Etats Unis, 78035 Versailles (France); Gerard, I., E-mail: gerard@chimie.uvsq.fr [Institut Lavoisier de Versailles (ILV-UMR 8180 CNRS/UVSQ), 45 av. des Etats Unis, 78035 Versailles (France); Hildebrandt, T.; Causier, A. [Institut Lavoisier de Versailles (ILV-UMR 8180 CNRS/UVSQ), 45 av. des Etats Unis, 78035 Versailles (France); Pelouard, J.L.; Dagher, G. [Laboratoire de Photonique et de Nanostructures (LPN-CNRS), route de Nozay 91460 Marcoussis (France); Jehl, Z.; Naghavi, N. [Institut de Recherche et Developpement sur l' Energie Photovoltaique (IRDEP -UMR 7174 CNRS/EDF/Chimie-ParisTech), 6 quai Watier, 78401 Chatou (France); Voorwinden, G.; Dimmler, B. [Wuerth Elektronik Research GmbH, Industriestr. 4, 70565 Stuttgart (Germany); Powalla, M. [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung (ZSW), Industriestr. 6, 70565 Stuttgart (Germany); Guillemoles, J.F. [Institut de Recherche et Developpement sur l' Energie Photovoltaique (IRDEP -UMR 7174 CNRS/EDF/Chimie-ParisTech), 6 quai Watier, 78401 Chatou (France); Lincot, D. [Laboratoire de Photonique et de Nanostructures (LPN-CNRS), route de Nozay 91460 Marcoussis (France); Etcheberry, A. [Institut Lavoisier de Versailles (ILV-UMR 8180 CNRS/UVSQ), 45 av. des Etats Unis, 78035 Versailles (France)

    2011-08-31

    CIGSe absorber was etched in HBr/Br{sub 2}/H{sub 2}O to prepare defined thicknesses of CIGSe between 2.7 and 0.5 {mu}m. We established a reproducible method of reducing the absorber thickness via chemical etching. We determine the dissolution kinetics rate of CIGSe using trace analysis by graphite furnace atomic absorption spectrometry of Ga and Cu. The roughness of the etching surface decreases during the first 500 nm of the etching to a steady state value of the root-mean-square roughness near 50 nm. X-ray photoelectron spectroscopy analyses demonstrate an etching process occurring with a constant chemical composition of the treated surface acidic bromine solutions provide a controlled chemical thinning process resulting in an almost flat surface and a very low superficial Se{sup 0} enrichment.

  2. Analysis of performance and device parameters of CIGS PV modules deployed outdoors

    Energy Technology Data Exchange (ETDEWEB)

    Radue, C. [Physics Department, P.O. Box 77000, Nelson Mandela Metropolitan University, Port Elizabeth, 6031 (South Africa)], E-mail: chantelle.radue@nmmu.ac.za; Dyk, E.E. van; Macabebe, E.Q. [Physics Department, P.O. Box 77000, Nelson Mandela Metropolitan University, Port Elizabeth, 6031 (South Africa)

    2009-02-02

    Two 20 W copper indium gallium diselenide photovoltaic modules were subjected to a thorough indoor assessment procedure, followed by outdoor deployment at the Nelson Mandela Metropolitan University as part of an ongoing study. The initial indoor measurement of maximum power output (P{sub MAX}) of one of the modules was considerably higher than the manufacturer's rating (E.E. van Dyk, C. Radue and A.R. Gxasheka, Thin Solid Films 515 (2007) 6196). The modules were deployed on a dual-axis solar tracker and current-voltage characteristics were obtained weekly. In addition to the normal PV parameters of short-circuit current, open-circuit voltage, P{sub MAX}, fill factor and efficiency, shunt and series resistances were also monitored. The performances of the two modules are compared and analyzed and the results presented in this paper.

  3. Fewer Cancer-Causing Chemicals in E-Cigs Than Regular Cigarettes

    Science.gov (United States)

    ... study suggests that smokers who completely switch to e-cigarettes and stop smoking tobacco cigarettes may significantly reduce ... of 12 years. For two weeks, they used e-cigarettes instead of tobacco cigarettes. During that time, their ...

  4. Elucidating the relationship between crystallo-chemistry and optical properties of CIGS nanocrystals

    Science.gov (United States)

    Ahmadi, Mahshid; Pramana, Stevin S.; Boothroyd, Chris; Lam, Yeng Ming

    2017-01-01

    The performance of solar cells fabricated using Cu(In,Ga)(S,Se)2 nanocrystal (NC) inks synthesized using the hot injection method has yielded efficiencies up to 12% recently. The efficiency of these devices is highly dependent on the chemical composition and crystallographic quality of the NCs. The former has been extensively discussed as it can be easily correlated to the optical properties of the film, but detailed crystallographic structure of these NCs has scarcely been discussed and it can influence both the optical and electrical properties. Hence both chemical composition and crystal structure should be explored for these NCs in order for this material to be further developed for application in thin film solar cells. In this work, a thorough investigation of the composition and crystal structure of CuIn x Ga1-x Se2 NCs synthesized using the hot injection method over the entire composition range (0 ≤ x ≤ 1) has been conducted. Raman spectroscopy of the NCs complements the information derived from x-ray diffraction (XRD) and electron probe microanalysis (EPMA). EPMA, which was carried out for the first time, indicates good controllability of the NC Ga/(In + Ga) ratio using this synthesis method. Raman spectroscopy reveals that CuInSe2 NCs are a mixture of chalcopyrite and sphalerite with disordered cations, whereas CuGaSe2 NCs are purely chalcopyrite. The lattice parameters determined from XRD were found to deviate from those calculated using Vegard’s law for all compositions. Hence, it can be deduced that the lattice is distorted in the crystal. The optical and electrochemical band gap of CuIn x Ga1-x Se2 NCs increases as the Ga content increases. The energy band gap deviates from the theoretical values, which could be related to the contribution from cation disordering and strain. These results help to tailor the opto-electrical properties of semiconductors, which inherently depend on the crystalline quality, strain and composition.

  5. Effect of Soft-annealing on the Properties of CIGSe Thin Films Prepared from Solution Precursors

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Shijoon; Park, Misun; Kim, Daehwan; Kang, Jinkyu [Daegu Gyeongbuk Institute of Science and Technology, Daegu (Korea, Republic of)

    2013-05-15

    Solution-based deposition of CuIn{sub x}Ga{sub 1-x}Se{sub 2} (CIGSe) thin films is well known non-vacuum process for the fabrication of CIGSe solar cells. However, due to the usage of organic chemicals in the preparation of CIG precursor solutions, the crystallization of the polycrystalline CIGSe and the performance of CIGSe thin film solar cells were significantly affected by the carbon residues from the organic chemicals. In this work, we have tried to eliminate the carbon residues in the CIG precursor thin films efficiently by using soft-annealing process. By adjusting soft-annealing temperature, it is possible to control the amount of carbon residues in CIG precursor thin films. The reduction of the carbon residues in CIG precursors by high temperature soft-annealing improves the grain size and morphology of polycrystalline CIGSe thin films, which are also closely related with the electrical properties of CIGSe thin film solar cells.

  6. Efficiently-designed hybrid tandem photovoltaic with organic and inorganic single cells

    Science.gov (United States)

    Vincent, Premkumar; Bae, Jin-Hyuk; Kim, Hyeok

    2016-05-01

    Conjugated polymers for solar-cell applications have been extensively studied and have proven highly beneficial in tandem solar-cell structures. This study focuses on achieving power conversion efficiencies of greater than 10% when in tandem with a highly efficient copper indium gallium diselenide (CIGS) solar cell. The optimal design is suggested based on the result of optical simulations on the organic-CIGS tandem structure. This is one of the first reports to show theoretically an organic-CIGS tandem solar cell to obtain an efficiency of greater than 10%. The best PCE was at a thickness of 200 nm for PTB7:PCBM, the active layer of the organic solar cell, and 400 nm for CIGS active layer. Our best datum showed an efficiency of 11.41% with a short-circuit current density of 11.56 mA/cm2 and a good spectral response at our optimized thicknesses.

  7. Nanoscale Measurements of the Surface Photovoltage in Cu(In,Ga)Se2, Cu2ZnSn4, and Cu2ZnSnSe4 Thin Films: The Role of the Surface Electronics on the Efficiency of Solar Cells: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Du, H.; Romero, M. J.; Repins, I.; Teeter, G.; Noufi, R.; Al-Jassim, M. M.

    2011-07-01

    We report on recent advances in the development of nanoscale measurements of the surface photovoltage (SPV) based on scanning tunneling microscopy (STM) and its application to the kesterites Cu2ZnSnS4 (CZTS) and Cu2ZnSnSe4 (CZTSe). One critical aspect of the electronic structure of Cu(In,Ga)Se2 (CIGS) that has yet to be determined in their related kesterite compounds is the character of the surface electronics. In CIGS, spontaneous deviations in the stoichiometry of the surface cause a depletion (or even a type inversion) region that reinforces the CIGS homojunction. First-principle calculations predict that this inversion region will be more difficult to form in CZTS. In this contribution, the characteristics of the surface space charge region for both CIGS and CZTS(e) are investigated by STM. The implications of the results of these measurements on the future development of CZTS solar cells will be discussed.

  8. The AMIGA sample of isolated galaxies XII. Revision of the isolation degree for AMIGA galaxies using the SDSS

    CERN Document Server

    Argudo-Fernández, M; Bergond, G; Sulentic, J; Sabater, J; Lorenzo, M Fernández; Leon, S; Espada, D; Verdes-Montenegro, L; Santander-Vela, J D; Ruiz, J E; Sánchez-Expósito, S

    2013-01-01

    In the framework of the AMIGA project we present a revision of the environment for galaxies in the Catalogue of Isolated Galaxies (CIG, Karachentseva 1973) using the ninth data release of the Sloan Digital Sky Survey (SDSS-DR9). The aims of this study are to refine the photometric-based AMIGA sample of isolated galaxies and to provide an improvement of the quantification of the isolation degree with respect to previous works, using both photometry and spectroscopy. We developed an automatic method to search for neighbours within a projected area of 1 Mpc radius centred on each primary galaxy to revise the CIG isolation criteria. Of the 636 CIG galaxies considered in the photometric study, 426 galaxies fulfil the CIG isolation criteria within 1 Mpc, taking into account projected neighbours. Of the 411 CIG galaxies considered in the spectroscopic study, 347 galaxies fulfil the CIG isolation criteria when a criterion about redshift difference is added. The available redshifts allow us to reject background neighb...

  9. Mg-composition induced effects on the physical behavior of sprayed Zn{sub 1-x}Mg{sub x}O films

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, K.T. Ramakrishna, E-mail: ktrkreddy@gmail.co [Thin Film Laboratory, Department of Physics, Sri Venkateswara University, Tirupati - 517 502 (India); Prathap, P.; Revathi, N.; Reddy, A.S.N. [Thin Film Laboratory, Department of Physics, Sri Venkateswara University, Tirupati - 517 502 (India); Miles, R.W. [School of Engineering and Computing, Northumbria University, Newcastle NE1 8ST (United Kingdom)

    2009-12-15

    Thin films of Zn{sub 1-x}Mg{sub x}O, with Mg compositions in the range, 0 < x < 0.4, have been deposited onto soda-lime glass substrates using chemical spray pyrolysis. The effects of altering the alloy composition on the chemical and physical properties of the layers were investigated using X-ray photoelectron spectroscopy, atomic force microscopy, Raman, optical and electrical measurements. The data shows systematic shifts in the properties of the layers with Mg-content. In particular, the optical absorption data showed that the influence of Mg-content on the energy gap of Zn{sub 1-x}Mg{sub x}O films is significant. Layers with x = 0.24 had an optical energy band gap, E{sub g} = 3.87 eV. The best layers produced had properties appropriate for application as Cd-free buffer layers in copper indium gallium selenide (CIGS) solar cells.

  10. Development of betavoltaic cell technology production based on microchannel silicon and its electrical parameters evaluation.

    Science.gov (United States)

    Krasnov, A A; Starkov, V V; Legotin, S A; Rabinovich, O I; Didenko, S I; Murashev, V N; Cheverikin, V V; Yakimov, E B; Fedulova, N A; Rogozev, B I; Laryushkin, A S

    2017-03-01

    In the paper a manufacturing process of three-dimensional (3D) microchannel structure by silicon (Si) anodic etching was discussed. The possibility of microchannels formation allows to increase the active area more than 100 times. In this structure the p-n junction on the whole Si surface was formed. The obtained data allowed to evaluate the characteristics of the betavoltaic converter with a 3D structure by using isotope 63Ni with a specific activity of 10Ci/g.

  11. ZnS/Zn(O,OH)S-based buffer layer deposition for solar cells

    Science.gov (United States)

    Bhattacharya, Raghu N.

    2009-11-03

    The invention provides CBD ZnS/Zn(O,OH)S and spray deposited ZnS/Zn(O,OH)S buffer layers prepared from a solution of zinc salt, thiourea and ammonium hydroxide dissolved in a non-aqueous/aqueous solvent mixture or in 100% non-aqueous solvent. Non-aqueous solvents useful in the invention include methanol, isopropanol and triethyl-amine. One-step deposition procedures are described for CIS, CIGS and other solar cell devices.

  12. Impact of the deposition conditions of buffer and windows layers on lowering the metastability effects in Cu(In,Ga)Se2/Zn(S,O)-based solar cell

    Science.gov (United States)

    Naghavi, Negar; Hildebrandt, Thibaud; Bouttemy, Muriel; Etcheberry, Arnaud; Lincot, Daniel

    2016-02-01

    The highest and most reproducible (Cu(In,Ga)Se2 (CIGSe) based solar-cell efficiencies are obtained by use of a very thin n-type CdS layer deposited by chemical bath deposition (CBD). However because of both Cadmium's adverse environmental impact and the narrow bandgap of CdS (2.4-2.5 eV) one of the major objectives in the field of CIGSe technology remains the development and implementation in the production line of Cd-free buffer layers. The CBDZn( S,O) remains one the most studied buffer layer for replacing the CdS in Cu(In,Ga)Se2-based solar cells and has already demonstrated its potential to lead to high-efficiency solar cells up to 22.3%. However one of the key issue to implement a CBD-Zn(S,O) process in a CIGSe production line is the cells stability, which depends both on the deposition conditions of CBD-Zn(S,O) and on a good band alignment between CIGSe/Zn(S,O)/windows layers. The most common window layers applied in CIGSe solar cells consist of two layers : a thin (50-100 nm) and highly resistive i-ZnO layer deposited by magnetron sputtering and a transparent conducting 300-500 nm ZnO:Al layer. In the case of CBD-Zn(S,O) buffer layer, the nature and deposition conditions of both Zn(S,O) and the undoped window layer can strongly influence the performance and stability of cells. The present contribution will be specially focused on the effect of condition growth of CBD-Zn(S,O) buffer layers and the impact of the composition and deposition conditions of the undoped window layers such as ZnxMgyO or ZnxSnyO on the stability and performance of these solar cells.

  13. Amorphous Indium Selenide Thin Films Prepared by RF Sputtering: Thickness-Induced Characteristics.

    Science.gov (United States)

    Han, Myoung Yoo; Park, Yong Seob; Kim, Nam-Hoon

    2016-05-01

    The influence of indium composition, controlled by changing the film thickness, on the optical and electrical properties of amorphous indium selenide thin films was studied for the application of these materials as Cd-free buffer layers in CI(G)S solar cells. Indium selenide thin films were prepared using RF magnetron sputtering method. The indium composition of the amorphous indium selenide thin films was varied from 94.56 to 49.72 at% by increasing the film thickness from 30 to 70 nm. With a decrease in film thickness, the optical transmittance increased from 87.63% to 96.03% and Eg decreased from 3.048 to 2.875 eV. Carrier concentration and resistivity showed excellent values of ≥1015 cm(-3) and ≤ 10(4) Ω x cm, respectively. The conductivity type of the amorphous indium selenide thin films could be controlled by changing the film-thickness-induced amount of In. These results indicate the possibility of tuning the properties of amorphous indium selenide thin films by changing their composition for use as an alternate buffer layer material in CI(G)S solar cells.

  14. Collision Detection and Overtaking Using Artificial Potential Fields in Car Racing game TORCS using Multi-Agent based Architecture

    OpenAIRE

    Salman, Muhammad

    2013-01-01

    The Car Racing competition platform is used for evaluating different car control solutions under competitive conditions [1]. These competitions are organized as part of the IEEE Congress on Evolutionary Computation (CEC) and Computational Intelligence and Games Sym-posium (CIG). The goal is to learn and develop a controller for a car in the TORCS open source racing game [2]. Oussama Khatib [3] (1986) introduced Artificial potential fields (APFs) for the first time while looking for new ways t...

  15. TGF-alpha genotypes, oral clefts, and environmental risk factors: A population-based California study

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, G.M.; Wasserman, C.R. [CA Birth Defects Monitoring Program, Emeryville, CA (United States); Lammer, E.J. [Stanford Univ., Palo Alto, CA (United States)] [and others

    1994-09-01

    Several studies have shown a relation between genetic variation at the TGF-alpha locus and oral clefts. These studies had limited sample sizes and also lacked data on additional factors potentially related to clefting. We investigated the influence on clefting from risk factors, such as maternal smoking, dependent on TFG-alpha genotype. This was accomplished using a large population-bases case-control study of fetuses and liveborn infants with oral clefts among a 1987-89 cohort of California births (N=548,844). To obtain data on potential risk factors, telephone interviews were conducted with mothers of 731 (84.5% of eligible) cleft cases, and 734 (78.2%) nonmalformed controls. DNA was obtained from newborn screening bloodspots and genotyped by using SSCP designed to detect the Taq1 RFLP. Among mothers who completed an interview, genotyping results were available for 571 (78.1%) cases and 640 (87.2%) controls. Compared to controls, the risk estimate for TGF-alpha polymorphism as measured by the odds ratio was: 0.99 (95% confidence interval 0.64, 1.5) for isolated cleft lip {plus_minus}palate; 0.88 (0.33, 2.2) for nonisolated cleft lip {plus_minus}palate; 1.6 (0.94, 2.8) for isolated cleft palate; 1.9 (0.82, 4.3) for nonisolated cleft palate; and 2.2 (0.99, 5.0) for clefts with known etiology. This dataset also revealed 1.4 to 2-fold increased risks for maternal cigarette smoking > 19 cigs/day in early pregnancy. Among these heavy smokers, risk of clefting was even more increased for infants with the TGF-alpha polymorphism. Our data suggest an association between the TGF-alpha uncommon allele and some phenotypic subgroups as well as provide evidence for a genetic-environment interaction between maternal smoking and the variant in the etiology of clefting. The fraction of cases possibly attributed to this interaction, however, was small.

  16. Investigations on electron beam evaporated Cu(In{sub 0.85}Ga{sub 0.15})Se{sub 2} thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Venkatachalam, M.; Kannan, M.D.; Prasanna, S.; Jayakumar, S.; Balasundaraprabhu, R. [Thin Film Center, Department of Physics, PSG College of Technology, Coimbatore (India); Muthukumarasamy, N. [Department of Physics, Coimbatore Institute of Technology, Coimbatore (India); Saroja, M. [Department of Electronics, Erode Arts College, Erode (India)

    2009-09-15

    CIGS bulk with composition of CuIn{sub 0.85}Ga{sub 0.15}Se{sub 2} was synthesized by direct reaction of elemental copper, indium, gallium and selenium. CIGS thin films were then deposited onto well-cleaned glass substrates using the prepared bulk alloy by electron beam deposition method. The structural properties of the deposited films were studied using X-ray diffraction technique. The as-deposited CIGS films were found to be amorphous. On annealing, the films crystallized with a tetragonal chalcopyrite structure. An intermediate Cu-rich phase precipitated at 200 C and dissociated at higher annealing temperatures. Average grain size calculated from the XRD spectra indicated that the films had a nano-crystalline structure and was further corroborated by AFM analysis of the sample surface. The chemical constituents present in the deposited CIGS films were identified using energy dispersive X-ray analysis. CIGS based solar cells were then fabricated on molybdenum and ITO coated glass substrates and the efficiencies have been evaluated. (author)

  17. Characterization of grain boundaries in Cu(In,Ga)Se{sub 2} by atom probe tomography

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, Torsten; Cojocaru-Miredin, Oana; Choi, Pyuck-Pa; Raabe, Dierk [Max-Planck Institute for Iron Research GmbH, Duesseldorf (Germany); Wuerz, Roland [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung Baden-Wuerttemberg (ZSW), Stuttgart (Germany)

    2012-07-01

    Solar cells based on the compound semiconductor Cu(In,Ga)Se{sub 2} (CIGS) as absorber material exhibit the highest efficiency among all thin-film solar cells. This is surprising high in view of the polycrystalline defect-rich structure of the CIGS absorber films. The high efficiency has been commonly ascribed to the diffusion of alkali metal atoms from the soda-lime glass substrate into the CIGS layer, which can render the grain boundaries (GB) electrically inactive. However, the exact mechanisms of how these impurities enhance the cell efficiency are yet to be clarified. As a step towards a better understanding of CIGS solar cells, we have analyzed the composition of solar-grade CIGS layers at the atomic-scale by using pulsed laser Atom Probe Tomography (APT). To perform APT analyses on selected GBs site-specific sample preparation was carried out using the Focused Ion Beam lift-out technique. In addition, Electron Back Scattered Diffraction was performed to characterize the structure and misorientation of selected GBs. Using APT, segregation of impurities at the GBs was directly observed. APT data of various types of GBs are presented and discussed with respect to the possible effects on the cell efficiency.

  18. Fabrication of solution processed 3D nanostructured CuInGaS₂ thin film solar cells.

    Science.gov (United States)

    Chu, Van Ben; Cho, Jin Woo; Park, Se Jin; Hwang, Yun Jeong; Park, Hoo Keun; Do, Young Rag; Min, Byoung Koun

    2014-03-28

    In this study we demonstrate the fabrication of CuInGaS₂ (CIGS) thin film solar cells with a three-dimensional (3D) nanostructure based on indium tin oxide (ITO) nanorod films and precursor solutions (Cu, In and Ga nitrates in alcohol). To obtain solution processed 3D nanostructured CIGS thin film solar cells, two different precursor solutions were applied to complete gap filling in ITO nanorods and achieve the desirable absorber film thickness. Specifically, a coating of precursor solution without polymer binder material was first applied to fill the gap between ITO nanorods followed by deposition of the second precursor solution in the presence of a binder to generate an absorber film thickness of ∼1.3 μm. A solar cell device with a (Al, Ni)/AZO/i-ZnO/CdS/CIGS/ITO nanorod/glass structure was constructed using the CIGS film, and the highest power conversion efficiency was measured to be ∼6.3% at standard irradiation conditions, which was 22.5% higher than the planar type of CIGS solar cell on ITO substrate fabricated using the same precursor solutions.

  19. Investigation of the diffusion behavior of sodium in Cu(In,Ga)Se{sub 2} layers

    Energy Technology Data Exchange (ETDEWEB)

    Laemmle, Anke, E-mail: anke.laemmle@zsw-bw.de; Wuerz, Roland; Powalla, Michael [Zentrum für Sonnenenergie- und Wasserstoff-Forschung Baden Württemberg, Industriestraße 6, 70565 Stuttgart (Germany); Schwarz, Torsten; Cojocaru-Mirédin, Oana; Choi, Pyuck-Pa [Max-Planck-Institut für Eisenforschung, Max-Planck-Str. 1, 40237 Düsseldorf (Germany)

    2014-04-21

    Sodium diffusion in Cu(In,Ga)Se{sub 2} (CIGS) layers was investigated over a temperature range from 157 °C to 400 °C. The diffusion profiles were measured by secondary ion mass spectrometry. Sodium ions diffused from a sodium fluoride (NaF) layer on the CIGS surface into the CIGS layer. From Na diffusion profiles, the diffusion along grain boundaries could be distinguished from the diffusion into the grain interior. Atom-probe tomography measurements reveal that even at a low temperature of 157 °C bulk diffusion of sodium into CIGS occurs. Based on this data, the slower diffusion coefficient in the volume can be described by the Arrhenius equation D{sub Na}{sup V} = 9.7 × 10{sup −9} exp(−0.36 eV/k{sub B}T) cm{sup 2} s{sup −1} and the fast diffusion along the grain boundaries by D{sub Na}{sup GB} = 6.5 × 10{sup −9} exp(−0.21 eV/k{sub B}T) cm{sup 2} s{sup −1}. Hence, we propose that sodium ions do not only passivate grain boundaries, but also act as dopants in the CIGS bulk.

  20. [Electronic cigarettes: A therapeutic tool, a social phenomenon or a business?].

    Science.gov (United States)

    Berlin, I

    2015-06-01

    Smoking is the first avoidable cause of morbidity and mortality. It is estimated that there were around 14 million smokers in France in 2012 and that smoking results in 70,000 deaths per year. All types of interventions reducing with efficacy the incidence and prevalence of smoking are to consider in prolonging life expectancy. Electronic cigarettes (e.cig.) are a social phenomenon but they also are a system delivering pharmacologically active substances; their use concerns today several millions of individuals in France. By this fact, it became important for clinical practitioners to acquire some knowledge about e. cig. Most of the e.cig. contains nicotine, thus, e.cig. are now called in the medical literature as electronic nicotine delivery system (ENDS). It is highly plausible that ENDS, which are, as of today, consumer products and not health products, deliver nicotine with a good bioavailability and could, if largely used, help to reduce smoking prevalence. However, because of current lack of regulations, as of today, the risk/benefit ratio of ENDS as an aid to help smokers quit and their adverse effect profile cannot be established. It is of public health responsibility to promote evidence based knowledge about e.cig. to know with confidence their risk/benefit ratio.

  1. Quantitative Analysis of Polycyclic Aromatic Hydrocarbons (PAHs Cited by the United States Food and Drug Administration

    Directory of Open Access Journals (Sweden)

    Guthery W

    2014-12-01

    Full Text Available The yields of 16 polycyclic aromatic hydrocarbons (PAHs were determined from cigarette mainstream smoke condensate extracts using Gas Chromatography- Tandem Mass Spectrometry (GC-MS/MS. The method has been validated for ISO and Health Canada Intense (HCI smoking protocols. Quantifiable levels (ISO means 0.16 to 365 ng/cig; HCI means 0.33 to 1595 ng/cig; n = 30 of 15 PAHs were found in the Kentucky reference cigarette K3R4F. The coefficient of variance (CV was derived from ten determinations each run in triplicate. The CV range was 8.7% to 24.8% (ISO and 6.6% to 24.3% (HCI. The limit of detection (LOD based on empirical precision was ≤ 0.06 ng/cig (ISO and ≤ 0.20 ng/cig (HCI for all components except naphthalene (2.89 and 9.62 ng/cig, respectively. The yields from 5 unspecified branded cigarettes (Samples A-E and 2 other reference cigarettes, K1R5F and the CORESTA monitor CM7, were determined under ISO smoking conditions. The same 15 PAHs were detected as in the K3R4F; however, cigarettes with lower yields of total particulate matter (TPM were found to contain significantly less PAHs. One component was measured below the limit of quantification (LOQ in Sample E and 2 components were < LOQ in the K1R5F.

  2. Effect of the KF post-deposition treatment on grain boundary properties in Cu(In, Ga)Se2 thin films

    Science.gov (United States)

    Nicoara, N.; Lepetit, Th.; Arzel, L.; Harel, S.; Barreau, N.; Sadewasser, S.

    2017-01-01

    Significant power conversion efficiency improvements have recently been achieved for thin-film solar cells based on a variety of polycrystalline absorbers, including perovskites, CdTe, and Cu(In,Ga)Se2 (CIGS). The passivation of grain boundaries (GBs) through (post-deposition) treatments is a crucial step for this success. For the case of CIGS, the introduction of a potassium fluoride post-deposition treatment (KF-PDT) has boosted their power conversion efficiency to the best performance of all polycrystalline solar cells. Direct and indirect effects of potassium at the interface and interface-near region in the CIGS layer are thought to be responsible for this improvement. Here, we show that also the electronic properties of the GBs are beneficially modified by the KF-PDT. We used Kelvin probe force microscopy to study the effect of the KF-PDT on the CIGS surface by spatially resolved imaging of the surface potential. We find a clear difference for the GB electronic properties: the KF-PDT increases the band bending at GBs by about 70% and results in a narrower distribution of work function values at the GBs. This effect of the KF-PDT on the GB electronic properties is expected to contribute to the improved efficiency values observed for CIGS thin-film solar cells with KF-PDT. PMID:28128351

  3. Physics of grain boundaries in polycrystalline photovoltaic semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Yanfa, E-mail: yanfa.yan@utoledo.edu; Yin, Wan-Jian; Wu, Yelong; Shi, Tingting; Paudel, Naba R. [Department of Physics and Astronomy and Wright Center for Photovoltaics Innovation and Commercialization, The University of Toledo, Ohio 43606 (United States); Li, Chen [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Poplawsky, Jonathan [The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Wang, Zhiwei [Department of Physics and Astronomy and Wright Center for Photovoltaics Innovation and Commercialization, The University of Toledo, Ohio 43606 (United States); National Renewable Energy Laboratory, Golden, Colorado 80401 (United States); Moseley, John; Guthrey, Harvey; Moutinho, Helio; Al-Jassim, Mowafak M. [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States); Pennycook, Stephen J. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States)

    2015-03-21

    Thin-film solar cells based on polycrystalline Cu(In,Ga)Se{sub 2} (CIGS) and CdTe photovoltaic semiconductors have reached remarkable laboratory efficiencies. It is surprising that these thin-film polycrystalline solar cells can reach such high efficiencies despite containing a high density of grain boundaries (GBs), which would seem likely to be nonradiative recombination centers for photo-generated carriers. In this paper, we review our atomistic theoretical understanding of the physics of grain boundaries in CIGS and CdTe absorbers. We show that intrinsic GBs with dislocation cores exhibit deep gap states in both CIGS and CdTe. However, in each solar cell device, the GBs can be chemically modified to improve their photovoltaic properties. In CIGS cells, GBs are found to be Cu-rich and contain O impurities. Density-functional theory calculations reveal that such chemical changes within GBs can remove most of the unwanted gap states. In CdTe cells, GBs are found to contain a high concentration of Cl atoms. Cl atoms donate electrons, creating n-type GBs between p-type CdTe grains, forming local p-n-p junctions along GBs. This leads to enhanced current collections. Therefore, chemical modification of GBs allows for high efficiency polycrystalline CIGS and CdTe thin-film solar cells.

  4. Effect of the KF post-deposition treatment on grain boundary properties in Cu(In, Ga)Se2 thin films

    Science.gov (United States)

    Nicoara, N.; Lepetit, Th.; Arzel, L.; Harel, S.; Barreau, N.; Sadewasser, S.

    2017-01-01

    Significant power conversion efficiency improvements have recently been achieved for thin-film solar cells based on a variety of polycrystalline absorbers, including perovskites, CdTe, and Cu(In,Ga)Se2 (CIGS). The passivation of grain boundaries (GBs) through (post-deposition) treatments is a crucial step for this success. For the case of CIGS, the introduction of a potassium fluoride post-deposition treatment (KF-PDT) has boosted their power conversion efficiency to the best performance of all polycrystalline solar cells. Direct and indirect effects of potassium at the interface and interface-near region in the CIGS layer are thought to be responsible for this improvement. Here, we show that also the electronic properties of the GBs are beneficially modified by the KF-PDT. We used Kelvin probe force microscopy to study the effect of the KF-PDT on the CIGS surface by spatially resolved imaging of the surface potential. We find a clear difference for the GB electronic properties: the KF-PDT increases the band bending at GBs by about 70% and results in a narrower distribution of work function values at the GBs. This effect of the KF-PDT on the GB electronic properties is expected to contribute to the improved efficiency values observed for CIGS thin-film solar cells with KF-PDT.

  5. Comparative Study of Zn(O,S) Buffer Layers and CIGS Solar Cells Fabricated by CBD, ALD, and Sputtering: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Ramanathan, K.; Mann, J.; Glynn, S.; Christensen, S.; Pankow, J.; Li, J.; Scharf, J.; Mansfield, L. M.; Contreras, M. A.; Noufi, R.

    2012-06-01

    Zn(O,S) thin films were deposited by chemical bath deposition (CBD), atomic layer deposition, and sputtering. Composition of the films and band gap were measured and found to follow the trends described in the literature. CBD Zn(O,S) parameters were optimized and resulted in an 18.5% efficiency cell that did not require post annealing, light soaking, or an undoped ZnO layer. Promising results were obtained with sputtering. A 13% efficiency cell was obtained for a Zn(O,S) emitter layer deposited with 0.5%O2. With further optimization of process parameters and an analysis of the loss mechanisms, it should be possible to increase the efficiency.

  6. Processing and Device Oriented Approach to CIGS Module Reliability; SunShot Initiative, U.S. Department of Energy (DOE)

    Energy Technology Data Exchange (ETDEWEB)

    Ramanathan, K.; Mansfield, L.; Garris, R.; Deline, C.; Silverman, T.

    2015-02-24

    Abstract: A device level understanding of thin film module reliability has been lacking. We propose that device performance and stability issues are strongly coupled and simultaneous attention to both is necessary. Commonly discussed technical issues such as light soaking, metastability, reverse bias breakdown and junction breakdown can be understood by comparing the behaviors of cells made inAbstract: A device level understanding of thin film module reliability has been lacking. We propose that device performance and stability issues are strongly coupled and simultaneous attention to both is necessary. Commonly discussed technical issues such as light soaking, metastability, reverse bias breakdown and junction breakdown can be understood by comparing the behaviors of cells made in the laboratory and industry. It will then be possible to attribute the observed effects in terms of processing and cell design. Process connection to stability studies can help identify root causes and a path for mitigating the degradation.

  7. Role of the buffer solution in the chemical deposition of CdS films for CIGS solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sooho; Kim, Donguk; Baek, Dohyun; Hong, Byoungyou; Yi, Junsin; Lee, Jaehyeong [Sungkyunkwan University, Suwon (Korea, Republic of); Park, Yongseob [Chosun College of Science and and Technology, Gwangju (Korea, Republic of); Choi, Wonseok [Hanbat National University, Daejeon (Korea, Republic of)

    2014-05-15

    In this work, the effects of NH{sub 4}Ac on the structural and the electro-optical properties of CdS films were investigated. CdS thin films were deposited on soda-lime glass and indium-tin-oxide (ITO) coated glass from a chemical bath containing 0.025 M cadmium acetate, 0 M ∼ 0.2 M ammonium acetate, 0.5 M thiourea, and ammonia. Cadmium acetate was the cadmium source, ammonium acetate served as a buffer, ammonia was the complexing agent, and thiourea was the source of sulfur. A commonly- available chemical bath deposition system was successfully modified to obtain precise control over the pH of the solution at 75 .deg. C during the deposition. Chemically deposited CdS films were studied by using field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), optical transmittance, and electrical resistivity measurements.

  8. Recycling of Indium From CIGS Photovoltaic Cells: Potential of Combining Acid-Resistant Nanofiltration with Liquid-Liquid Extraction.

    NARCIS (Netherlands)

    Zimmermann, Y.S.; Niewersch, C.; Lenz, M.; Corvini, P.F.X.; Schäffer, A.; Wintgens, T.

    2014-01-01

    Electronic consumer products such as smartphones, TV, computers, light-emitting diodes, and photovoltaic cells crucially depend on metals and metalloids. So-called “urban mining” considers them as secondary resources since they may contain precious elements at concentrations many times higher than t

  9. Motor hidráulico de alto torque de cilindros y cigüeñal

    Directory of Open Access Journals (Sweden)

    Guillermo Arias Polo

    2008-01-01

    Full Text Available El presente trabajo contiene una nueva invención ®, de un tipo de motor hidráulico, para las aplicaciones llamadas de alto torque y baja velocidad de rotación, donde como característica, no es necesario interponer algún escalón de reducción de velocidad entre el motor y el equipo a ser movido. Esta sencilla maquinaria en su construcción tiene el atractivo de utilizar componentes de tecnología muy común en la práctica, de bajo costo, y de poca complejidad. Está compuesto esencialmente por tres cilindros hidráulicos de doble efecto y una válvula distribuidora de flujo rotatoria, montado todo en un bastidor. Tiene la novedad patentada que los tres cilindros hidráulicos mencionados realizan trabajo útil tanto a la ida como al regreso de su carrera, hecho este que le confiere una densidad de torque/masa superior a las soluciones conocidas. Se presenta un prototipo que trabajó en condiciones reales de producción en el ingenio Habana Libre de Cuba, con resultados muy prometedores. Se presenta además, el diseño de un nuevo modelo más robusto, mejorando las prestaciones del prototipo experimental.

  10. CdS and Cd-Free Buffer Layers on Solution Phase Grown Cu2ZnSn(SxSe1- x)4 :Band Alignments and Electronic Structure Determined with Femtosecond Ultraviolet Photoemission Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Haight, Richard; Barkhouse, Aaron; Wang, Wei; Yu, Luo; Shao, Xiaoyan; Mitzi, David; Hiroi, Homare; Sugimoto, Hiroki

    2013-12-02

    The heterojunctions formed between solution phase grown Cu2ZnSn(SxSe1- x)4(CZTS,Se) and a number of important buffer materials including CdS, ZnS, ZnO, and In2S3, were studied using femtosecond ultraviolet photoemission spectroscopy (fs-UPS) and photovoltage spectroscopy. With this approach we extract the magnitude and direction of the CZTS,Se band bending, locate the Fermi level within the band gaps of absorber and buffer and measure the absorber/buffer band offsets under flatband conditions. We will also discuss two-color pump/probe experiments in which the band bending in the buffer layer can be independently determined. Finally, studies of the bare CZTS,Se surface will be discussed including our observation of mid-gap Fermi level pinning and its relation to Voc limitations and bulk defects.

  11. Electrodeposition of chalcopyrite films from ionic liquid electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Shivagan, D.D. [Department of Chemistry, University of Bath, BATH BA2 7AY (United Kingdom)]. E-mail: d.shivagan@bath.ac.uk; Dale, P.J. [Department of Chemistry, University of Bath, BATH BA2 7AY (United Kingdom); Samantilleke, A.P. [Department of Chemistry, University of Bath, BATH BA2 7AY (United Kingdom); Peter, L.M. [Department of Chemistry, University of Bath, BATH BA2 7AY (United Kingdom)]. E-mail: l.m.peter@bath.ac.uk

    2007-05-31

    An air and water stable room-temperature ionic liquid based on choline chloride/urea eutectic mixture has been investigated as a system for the electrodeposition of CuInSe{sub 2} (CIS) and Cu(In,Ga)Se{sub 2} (CIGS) films for photovoltaic applications. Deposition potentials and bath compositions were optimized to obtain Cu-In, Cu-In-Se and Cu-In-Ga-Se precursor films, which were selenized in a tube furnace at 500 deg. C for 30 min to form CIS and CI(G)S films. Photo-electrochemical measurements on these selenized films showed p-type photoconductivity with band gaps of 1.0 eV and 1.09 eV, respectively, for CIS and CIGS. The films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), photocurrent spectroscopy and electrolyte electro-reflectance spectroscopy (EER)

  12. New processing approaches for Cu2ZnSnSe4-based solar cells

    OpenAIRE

    López Mariño, Simón

    2016-01-01

    The present thesis focuses on the promising semiconductor material kesterite, Cu2ZnSn(S,Se)4, known as CZTS(e), which is used in the second generation of solar cells, generally known as thin film photovoltaics (PV). This material relies on earth-abundant, low-cost and low toxic elements which certainly attract the interest of both research community and industry. Kesterite could replace its well known and already commercialised thin film counterpart, CuIn(1-x)Gax(SySe1-y)2 (CIGS), since it ha...

  13. Challenge of replacing CdS in CuInSe{sub 2}-based solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, L.C.; Addis, F.W.; Lei, W.; Aguilar, H. [Washington State University at Tri-Cities, 100 Sprout Rd., Richland, Washington 99352 (United States)

    1997-02-01

    This paper discusses some key issues concerning the replacement of CdS buffer layers in CIS solar cell structures, and describes investigations of alternative buffer layers deposited by MOCVD. One apparently unique property of CdS buffer layers grown by CBD is that a ZnO TCO can be deposited on top of a CdS/CIS structure without significantly degrading the photovoltaic properties of the CdS-CIS junction. Investigation of alternative buffer materials such as high resistance ZnO (i-ZnO), ZnSe and InSe have first identified MOCVD growth procedures that yield Al/X/CIS test structures (X=i-ZnO, ZnSe and InSe) with good properties, and then addressed the challenge of fabricating efficient, complete cells with conductive ZnO top contact layers. These studies have been conducted with Siemens CIS and CIGSS substrates, and with NREL CIGS substrates. A total area efficiency of 12.7{percent} and estimated active area efficiency of 13.4{percent} is reported for a CIGS cell with an i-ZnO buffer layer grown by MOCVD. {copyright} {ital 1997 American Institute of Physics.}

  14. Challenge of replacing CdS in CuInSe2-based solar cells

    Science.gov (United States)

    Olsen, Larry C.; Addis, F. William; Lei, Wenhua; Aguilar, Heriberto

    1997-02-01

    This paper discusses some key issues concerning the replacement of CdS buffer layers in CIS solar cell structures, and describes investigations of alternative buffer layers deposited by MOCVD. One apparently unique property of CdS buffer layers grown by CBD is that a ZnO TCO can be deposited on top of a CdS/CIS structure without significantly degrading the photovoltaic properties of the CdS-CIS junction. Investigation of alternative buffer materials such as high resistance ZnO (i-ZnO), ZnSe and InSe have first identified MOCVD growth procedures that yield Al/X/CIS test structures (X=i-ZnO, ZnSe and InSe) with good properties, and then addressed the challenge of fabricating efficient, complete cells with conductive ZnO top contact layers. These studies have been conducted with Siemens CIS and CIGSS substrates, and with NREL CIGS substrates. A total area efficiency of 12.7% and estimated active area efficiency of 13.4% is reported for a CIGS cell with an i-ZnO buffer layer grown by MOCVD.

  15. Degradation of Cu(In, Ga)Se{sub 2} thin-film solar cells due to the ionization effect of low-energy electrons

    Energy Technology Data Exchange (ETDEWEB)

    Kawakita, Shirou, E-mail: kawakita.shirou@jaxa.jp [Japan Aerospace Exploration Agency (JAXA), Tsukuba, Ibaraki 305-8505 (Japan); Imaizumi, Mitsuru [Japan Aerospace Exploration Agency (JAXA), Tsukuba, Ibaraki 305-8505 (Japan); Ishizuka, Shogo; Shibata, Hajime; Niki, Shigeru [National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Okuda, Shuichi [Osaka Prefecture University (OPU), Sakai, Osaka 599-8570 (Japan); Kusawake, Hiroaki [Japan Aerospace Exploration Agency (JAXA), Tsukuba, Ibaraki 305-8505 (Japan)

    2015-05-01

    Cu (In, Ga)Se{sub 2} (CIGS) solar cells were irradiated with 100 keV electrons to reveal the characteristics of created radiation defects. 100 keV electrons cannot produce any displacement defects in CIGS. Low-fluence electrons improve the electrical performance of the CIGS solar cells due to the change in the conductive type of donor to acceptor in a metastable defect, which is equivalent to the light-soaking effect. However, high fluence electrons cause the cell performance to decline. From analysis based on changes in carrier density and electroluminescence, defects causing the decline in performance include donor- and non-radiative types. In addition, red-on-bias experiments showed an increase in III{sub Cu} defects due to electron irradiation. Based on these results, the degradation in the electrical performance of the CIGS solar cells irradiated with high electron fluence would be attributable to a change in the conductive type of III{sub Cu} defects. - Highlights: • Cu(In,Ga)Se2 Solar cells were irradiated with 100 and 250 keV electrons at low temperature. • These electrons degraded the electrical performance of Cu(In,Ga)Se2 sola cells. • The electrons induced ⅢCu defects in Cu(In,Ga)Se2.

  16. Touch BASE

    CERN Multimedia

    Antonella Del Rosso

    2015-01-01

    In a recent Nature article (see here), the BASE collaboration reported the most precise comparison of the charge-to-mass ratio of the proton to its antimatter equivalent, the antiproton. This result is just the beginning and many more challenges lie ahead.   CERN's AD Hall, where the BASE experiment is set-up. The Baryon Antibaryon Symmetry Experiment (BASE) was approved in June 2013 and was ready to take data in August 2014. During these 14 months, the BASE collaboration worked hard to set up its four cryogenic Penning traps, which are the heart of the whole experiment. As their name indicates, these magnetic devices are used to trap antiparticles – antiprotons coming from the Antiproton Decelerator – and particles of matter – negative hydrogen ions produced in the system by interaction with a degrader that slows the antiprotons down, allowing scientists to perform their measurements. “We had very little time to set up the wh...

  17. Behavior of Photocarriers in the Light-Induced Metastable State in the p-n Heterojunction of a Cu(In,Ga)Se2 Solar Cell with CBD-ZnS Buffer Layer.

    Science.gov (United States)

    Lee, Woo-Jung; Yu, Hye-Jung; Wi, Jae-Hyung; Cho, Dae-Hyung; Han, Won Seok; Yoo, Jisu; Yi, Yeonjin; Song, Jung-Hoon; Chung, Yong-Duck

    2016-08-31

    We fabricated Cu(In,Ga)Se2 (CIGS) solar cells with a chemical bath deposition (CBD)-ZnS buffer layer grown with varying ammonia concentrations in aqueous solution. The solar cell performance was degraded with increasing ammonia concentration, due to actively dissolved Zn atoms during CBD-ZnS precipitation. These formed interfacial defect states, such as hydroxide species in the CBD-ZnS film, and interstitial and antisite Zn defects at the p-n heterojunction. After light/UV soaking, the CIGS solar cell performance drastically improved, with a rise in fill factor. With the Zn-based buffer layer, the light soaking treatment containing blue photons induced a metastable state and enhanced the CIGS solar cell performance. To interpret this effect, we suggest a band structure model of the p-n heterojunction to explain the flow of photocarriers under white light at the initial state, and then after light/UV soaking. The determining factor is a p+ defect layer, containing an amount of deep acceptor traps, located near the CIGS surface. The p+ defect layer easily captures photoexcited electrons, and then when it becomes quasi-neutral, attracts photoexcited holes. This alters the barrier height and controls the photocurrent at the p-n junction, and fill factor values, determining the solar cell performance.

  18. Progress in Polycrystalline Thin-Film Cu(In,GaSe2 Solar Cells

    Directory of Open Access Journals (Sweden)

    Udai P. Singh

    2010-01-01

    Full Text Available For some time, the chalcopyrite semiconductor CuInSe2 and its alloy with Ga and/or S [Cu(InGaSe2 or Cu(InGa(Se,S2], commonly referred as CIGS, have been leading thin-film material candidates for incorporation in high-efficiency photovoltaic devices. CuInSe2-based solar cells have shown long-term stability and the highest conversion efficiencies among all thin-film solar cells, reaching 20%. A variety of methods have been reported to prepare CIGS thin film. Efficiency of solar cells depends upon the various deposition methods as they control optoelectronic properties of the layers and interfaces. CIGS thin film grown on glass or flexible (metal foil, polyimide substrates require p-type absorber layers of optimum optoelectronic properties and n-type wideband gap partner layers to form the p-n junction. Transparent conducting oxide and specific metal layers are used for front and back contacts. Progress made in the field of CIGS solar cell in recent years has been reviewed.

  19. Self-assembled synthesis of 3D Cu(In1 - xGax)Se2 nanoarrays by one-step electroless deposition into ordered AAO template

    Science.gov (United States)

    Zhang, Bin; Zhou, Tao; Zheng, Maojun; Xiong, Zuzhou; Zhu, Changqing; Li, Hong; Wang, Faze; Ma, Li; Shen, Wenzhong

    2014-07-01

    Quaternary nanostructured Cu(In1 - xGax)Se2 (CIGS) arrays were successfully fabricated via a novel and simple solution-based protocol on the electroless deposition method, using a flexible, highly ordered anodic aluminium oxide (AAO) substrate. This method does not require electric power, complicated sensitization processes, or complexing agents, but provides nearly 100% pore fill factor to AAO templates. The field emission scanning electron microscopy (FE-SEM) images show that we obtained uniformly three-dimensional nanostructured CIGS arrays, and we can tailor the diameter and wall thicknesses of the nanostructure by adjusting the pore diameter of the AAO and metal Mo layer. Their chemical composition was determined by energy-dispersive spectroscopy analysis, which is very close to the stoichiometric value. The Raman spectroscopy, x-ray diffraction (XRD) pattern, and transmission electron microscopy (TEM) further confirm the formation of nanostructured CIGS with prominent chalcopyrite structure. The nanostructured CIGS arrays can support the design of low-cost, highlight-trapping, and enhanced carrier collection nanostructured solar cells.

  20. Beneficial Effect of Post-Deposition Treatment in High-Efficiency Cu(In,Ga)Se2 Solar Cells through Reduced Potential Fluctuations

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Soren A.; Glynn, Stephen; Kanevce, Ana; Dippo, Pat; Li, Jian V.; Levi, Dean H.; Kuciauskas, Darius

    2016-08-14

    World-record power conversion efficiencies for Cu(In,Ga)Se2 (CIGS) solar cells have been achieved via a post-deposition treatment with alkaline metals, which increases the open-circuit voltage and fill factor. We explore the role of the potassium fluoride (KF) post-deposition treatment in CIGS by employing energy- and time-resolved photoluminescence spectroscopy and electrical characterization combined with numerical modeling. The bulk carrier lifetime is found to increase with post-deposition treatment from 255 ns to 388 ns, which is the longest charge carrier lifetime reported for CIGS, and within ~40% of the radiative limit. We find evidence that the post-deposition treatment causes a decrease in the electronic potential fluctuations. These potential fluctuations have previously been shown to reduce the open-circuit voltage and the device efficiency in CIGS. Additionally, numerical simulations based on the measured carrier lifetimes and mobilities show a diffusion length of ~10 um, which is ~4 times larger than the film thickness. Thus, carrier collection in the bulk is not a limiting factor for device efficiency. By considering differences in doping, bandgap, and potential fluctuations, we present a possible explanation for the voltage difference between KF-treated and untreated samples.

  1. Nanoscale Measurements of the Surface Photovoltage in Cu(In,Ga)Se2, Cu2ZnSnS4, and Cu2ZnSnSe4 Thin Films: The Role of the Surface Electronics on the Efficiency of Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Du, H.; Romero, M. J.; Repins, I.; Teeter, G.; Noufi, R.; Al-Jassim, M. M.

    2011-01-01

    We report on recent advances in the development of nanoscale measurements of the surface photovoltage (SPV) based on scanning tunneling microscopy (STM) and its application to the kesterites Cu{sub 2}ZnSnS{sub 4} (CZTS) and Cu{sub 2}ZnSnSe{sub 4} (CZTSe). One critical aspect of the electronic structure of Cu(In, Ga)Se{sub 2} (CIGS) that has yet to be determined in their related kesterite compounds is the character of the surface electronics. In CIGS, spontaneous deviations in the stoichiometry of the surface cause a depletion (or even a type inversion) region that reinforces the CIGS homojunction. First-principle calculations predict that this inversion region will be more difficult to form in CZTS. In this contribution, the characteristics of the surface space charge region for both CIGS and CZTS(e) are investigated by STM. The implications of the results of these measurements on the future development of CZTS solar cells will be discussed.

  2. Self-assembled synthesis of 3D Cu(In(1-x)Ga(x))Se2 nanoarrays by one-step electroless deposition into ordered AAO template.

    Science.gov (United States)

    Zhang, Bin; Zhou, Tao; Zheng, Maojun; Xiong, Zuzhou; Zhu, Changqing; Li, Hong; Wang, Faze; Ma, Li; Shen, Wenzhong

    2014-07-25

    Quaternary nanostructured Cu(In1 - xGax)Se2 (CIGS) arrays were successfully fabricated via a novel and simple solution-based protocol on the electroless deposition method, using a flexible, highly ordered anodic aluminium oxide (AAO) substrate. This method does not require electric power, complicated sensitization processes, or complexing agents, but provides nearly 100% pore fill factor to AAO templates. The field emission scanning electron microscopy (FE-SEM) images show that we obtained uniformly three-dimensional nanostructured CIGS arrays, and we can tailor the diameter and wall thicknesses of the nanostructure by adjusting the pore diameter of the AAO and metal Mo layer. Their chemical composition was determined by energy-dispersive spectroscopy analysis, which is very close to the stoichiometric value. The Raman spectroscopy, x-ray diffraction (XRD) pattern, and transmission electron microscopy (TEM) further confirm the formation of nanostructured CIGS with prominent chalcopyrite structure. The nanostructured CIGS arrays can support the design of low-cost, highlight-trapping, and enhanced carrier collection nanostructured solar cells.

  3. Web based foundry knowledge base

    Directory of Open Access Journals (Sweden)

    A. Stawowy

    2009-01-01

    Full Text Available The main assumptions and functions of proposed Foundry Knowledge Base (FKB are presented in this paper. FKB is a framework forinformation exchange of casting products and manufacturing methods. We use CMS (Content Management System to develope andmaintain our web-based system. The CastML – XML dialect developed by authors for description of casting products and processes – isused as a tool for information interchange between ours and outside systems, while SQL is used to store and edit knowledge rules and alsoto solve the basic selection problems in the rule-based module. Besides the standard functions (companies data, news, events, forums and media kit, our website contains a number of nonstandard functions; the intelligent search module based on expert system is the main advantage of our solution. FKB is to be a social portal which content will be developed by foundry community.

  4. Analysis and optimization of thin film photovoltaic materials and device fabrication by real time spectroscopic ellipsometry

    Science.gov (United States)

    Li, Jian; Stoke, Jason A.; Podraza, Nikolas J.; Sainju, Deepak; Parikh, Anuja; Cao, Xinmin; Khatri, Himal; Barreau, Nicolas; Marsillac, Sylvain; Deng, Xunming; Collins, Robert W.

    2007-09-01

    Methods of spectroscopic ellipsometry (SE) have been applied to investigate the growth and properties of the material components used in the three major thin film photovoltaics technologies: (1) hydrogenated silicon (Si:H); (2) cadmium telluride (CdTe); and (3) copper indium-gallium diselenide (CuIn 1-xGa xSe2 or CIGS). In Si:H technology, real time SE (RTSE) has been applied to establish deposition phase diagrams that describe very high frequency (vhf) plasmaenhanced chemical vapor deposition (PECVD) processes for hydrogenated silicon (Si:H) and silicon-germanium alloy (Si 1-xGe x:H) thin films. This study has reaffirmed that the highest efficiencies for a-Si:H and a-Si 1-xGe x:H component solar cells of multijunction devices are obtained when the i-layers are prepared under maximal H II dilution conditions. In CdTe technology, the magnetron sputter deposition of polycrystalline CdTe, CdS, and CdTe 1-xS x thin films as well as the formation of CdS/CdTe and CdTe/CdS heterojunctions has been studied. The nucleation and growth behaviors of CdTe and CdS show strong variations with deposition temperature, and this influences the ultimate grain size. The dielectric functions ɛ of the CdTe 1-xS x alloys have been deduced in order to set up a database for real time investigation of inter-diffusion at the CdS/CdTe and CdTe/CdS interfaces. In CIGS technology, strong variations in ɛ of the Mo back contact during sputter deposition have been observed, and these results have been understood applying a Drude relaxation time that varies with the Mo film thickness. Ex-situ SE measurements of a novel In IIS 3 window layer have shown critical point structures at 2.77+/-0.08 eV, 4.92+/-0.005 eV, and 5.64+/-0.005 eV, as well as an absorption tail with an onset near 1.9 eV. Simulations of solar cell performance comparing In IIS 3 and the conventional CdS have revealed similar quantum efficiencies, suggesting the possibility of a Cd-free window layer in CIGS technology.

  5. Analysis of the process of representing clinical statements for decision-support applications: a comparison of openEHR archetypes and HL7 virtual medical record.

    Science.gov (United States)

    González-Ferrer, A; Peleg, M; Marcos, M; Maldonado, J A

    2016-07-01

    Delivering patient-specific decision-support based on computer-interpretable guidelines (CIGs) requires mapping CIG clinical statements (data items, clinical recommendations) into patients' data. This is most effectively done via intermediate data schemas, which enable querying the data according to the semantics of a shared standard intermediate schema. This study aims to evaluate the use of HL7 virtual medical record (vMR) and openEHR archetypes as intermediate schemas for capturing clinical statements from CIGs that are mappable to electronic health records (EHRs) containing patient data and patient-specific recommendations. Using qualitative research methods, we analyzed the encoding of ten representative clinical statements taken from two CIGs used in real decision-support systems into two health information models (openEHR archetypes and HL7 vMR instances) by four experienced informaticians. Discussion among the modelers about each case study example greatly increased our understanding of the capabilities of these standards, which we share in this educational paper. Differing in content and structure, the openEHR archetypes were found to contain a greater level of representational detail and structure while the vMR representations took fewer steps to complete. The use of openEHR in the encoding of CIG clinical statements could potentially facilitate applications other than decision-support, including intelligent data analysis and integration of additional properties of data items from existing EHRs. On the other hand, due to their smaller size and fewer details, the use of vMR potentially supports quicker mapping of EHR data into clinical statements.

  6. Optimization of Post-selenization Process of Co-sputtered CuIn and CuGa Precursor for 11.19% Efficiency Cu(In, Ga)Se2 Solar Cells

    Science.gov (United States)

    Cheng, Ke; Han, Kaikai; Kuang, Zhongcheng; Jin, Ranran; Hu, Junxia; Guo, Longfei; Liu, Ya; Lu, Zhangbo; Du, Zuliang

    2017-04-01

    In this work, CuInGa alloy precursor films are fabricated by co-sputtering of CuIn and CuGa targets simultaneously. After selenization in a tube-type rapid thermal annealing system under a Se atmosphere, the Cu(In, Ga)Se2 (CIGS) absorber layers are obtained. Standard soda lime glass (SLG)/Mo/CIGS/CdS/i-ZnO/ITO/Ag grid structural solar cells are fabricated based on the selenized CIGS absorbers. The influences of selenization temperatures on the composition, crystallinity, and device performances are systematically investigated by x-ray energy dispersive spectroscopy, x-ray diffraction, Raman spectroscopy, and the current density-voltage ( J- V) measurement. It is found that the elemental ratio of Cu/(In + Ga) strongly depends on the selenization temperatures. Because of the appropriate elemental ratio, a 9.92% conversion efficiency is reached for the CIGS absorber selenized at 560°C. After the additional optimization by pre-annealing treatment at 280°C before the selenization, a highest conversion efficiency of 11.19% with a open-circuit ( V oc) of 456 mV, a short-circuit ( J sc) of 40.357 mA/cm2 and a fill factor of 60.82% without antireflection coating has been achieved. Above 13% efficiency improvement was achievable. Our experimental findings presented in this work demonstrate that the post-selenization of co-sputtered CuIn and CuGa precursor is a promising way to fabricate high quality CIGS absorbers.

  7. Room-Temperature Chemical Solution Treatment for Flexible ZnS(O,OH)/Cu(In,Ga)Se2 Solar Cell: Improvements in Interface Properties and Metastability.

    Science.gov (United States)

    Ho, Wei-Hao; Hsu, Chia-Hao; Yeh, Tzu-Hsuan; Chang, Yu-Han; Wei, Shih-Yuan; Lin, Tzu-Ying; Lai, Chih-Huang

    2016-03-01

    We demonstrate an effective room-temperature chemical solution treatment, by using thioacetamide (S treatment) or thioacetamide-InCl3 (In-S treatment) solution, on Cu(In,Ga)Se2 (CIGSe) surface to engineer the ZnS(O,OH)/CIGSe interface and junction quality, leading to enhanced efficiency and minimized metastability of flexible solar cells. The control device without treatment reveals a relatively low efficiency of 8.15%, which is significantly improved to 9.74% by In-S treatment, and 10.39% by S treatment. Results of X-ray photoelectron spectroscopy suggest that S is incorporated into CIGSe surface forming CIGSSe by S treatment, whereas a thin In-S layer is formed on CIGSe surface by In-S treatment with reduced amount of S diffusing into CIGSe. PL spectra and TRPL lifetime further reveal that S incorporation into CIGS surface may substitute the OSe and/or directly occupy the vacant anion site (VSe), resulting in the effective passivation of the recombination centers at CIGSe surface. Moreover, reducing the concentrations of VSe may thereby decrease the density of (VCu-VSe) acceptors, which can minimize the metastability of ZnS(O,OH)/CIGSe solar cells. With S treatment, the light soaking (LS) time of ZnS(O,OH)/CIGSe device is reduced approximately to one-half of control one. Our approach can be potentially applied for alternative Cd-free buffer layers to achieve high efficiency and low metastability.

  8. Junction formation in CuInSe{sub 2}-based thin-film devices

    Energy Technology Data Exchange (ETDEWEB)

    Ramanathan, K.; Wiesner, H.; Asher, S.; Bhattacharya, R.N.; Keane, J.; Contreras, M.A.; Noufi, R. [National Center for Photovoltaics, National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401 (United States)

    1999-03-01

    The nature of the interface between CuInSe{sub 2} (CIS) and the chemical bath deposited CdS layer has been investigated. We show that heat-treating the absorbers in Cd- or Zn-containing solutions in the presence of ammonium hydroxide sets up a chemical reaction which facilitates an extraction of Cu from the lattice and an in-diffusion of Cd. The characteristics of devices made in this manner suggest that the reaction generates a thin, n-doped region in the absorber. It is quite possible that the CdS/CuInSe{sub 2} device is a buried, shallow junction with a CdS window layer, rather than a heterojunction. We have used these ideas to develop methods for fabricating devices without CdS or Cd. A 14.2{percent} efficiency ZnO/CIGS device was obtained through aqueous treatment in Zn solutions. {copyright} {ital 1999 American Institute of Physics.}

  9. Junction Formation in CuInSe{sub 2} Based Thin Film Devices

    Energy Technology Data Exchange (ETDEWEB)

    Ramanathan, K.; Wiesner, H.; Asher, S.; Bhattacharya, R. N.; Keane, J.; Contreras, M.; Noufi, R.

    1998-11-18

    The nature of the interface between CuInSe{sub 2} (CIS) and the chemical bath deposited CdS layer has been investigated. We show that heat-treating the absorbers in Cd- or Zn-containing solutions in the presence of ammonium hydroxide sets up a chemical reaction which facilitates an extraction of Cu from the lattice and an in-diffusion of Cd. The characteristics of devices made in this manner suggest that the reaction generates a thin, n-doped region in the absorber. It is quite possible that the CdS/CuInSe{sub 2} device is a buried, shallow junction with a CdS window layer, rather than a heterojunction. We have used these ideas to develop methods for fabricating devices without CdS or Cd. A 14.2% efficiency ZnO/CIGS device was obtained through aqueous treatment in Zn solutions.

  10. Immunohistological analysis in diagnosis of plasma cell myeloma based on cytoplasmic kappa/lambda ratio of CD38-positive plasma cells.

    Science.gov (United States)

    Nakayama, Shoko; Yokote, Taiji; Hirata, Yuji; Iwaki, Kazuki; Akioka, Toshikazu; Miyoshi, Takuji; Nishiwaki, Uta; Masuda, Yuki; Hiraoka, Nobuya; Takayama, Ayami; Nishimura, Yasuichiro; Tsuji, Motomu; Hanafusa, Toshiaki

    2012-11-01

    The accurate determination of cytoplasmic immunoglobulin (cIg) light chain (LC) expression is important to differentiate reactive plasmacytosis from a clonal plasma cell neoplasm such as plasma cell myeloma (PCM). Through retrospective analysis, we studied the cytoplasmic kappa/lambda ratio of CD38-positive plasma cells in the bone marrow from 19 PCM patients and 19 controls. To demonstrate cIg LC expression, the bone marrow was immunostained for IgA, IgG, IgM, kappa, and lambda. The kappa/lambda ratio was defined as the ratio of the kappa-positive cell to the lambda-positive cell in plasma cells. PCM cells were distinguished from normal plasma cells by cut-off levels between 0.59 and 4.0, a sensitivity of 94.7%, and a specificity of 94.7%. The detection of the cytoplasmic kappa/lambda ratio of CD38-positive plasma cells may be a useful tool in the diagnosis of PCM and the correct diagnosis of PCM may be achieved more simply.

  11. Research Advances of CIGS Cells, Target and Single Target Sputtering Progress%CIGS电池、靶材及单靶溅射工艺研究进展

    Institute of Scientific and Technical Information of China (English)

    王丹; 余洲; 冀亚欣; 闫勇; 欧玉峰; 晏传鹏; 刘连; 张勇; 赵勇

    2016-01-01

    综述了蒸发法、溅射后硒化法、单靶直接溅射法制备CIGS光吸收层的工艺和电池性能,比较了它们的优缺点;详细介绍了粉末冶金参数(如烧结温度、压力、时间)对制备CIGS靶材致密度、成分均匀性的影响;着重阐述了单靶溅射工艺参数(如衬底温度、溅射功率、工作气压)对沉积的CIGS薄膜的相结构、形貌、光学及电学性能的影响.

  12. Dialektika cigánské férovky. Příspěvek ke kritické antropologii bezpečnosti

    Directory of Open Access Journals (Sweden)

    Václav Walach

    2013-12-01

    Full Text Available Within a Czech socially excluded locality,street violence is recognized as a serious securitythreat. This paper deals with several interpretationsof this phenomenon which is oftentimessymbolized as the ‘Gypsy fair fight’. It is analyzedvia the dialectical method structured around thethesis–antithesis–synthesis conceptual triad.While a prevailing explication in the discourseof respective locale comprehends street violencein terms of ethnic conflict, a less frequent one opposesthis interpretation on the basis of culturalconflict between the so-called decent and inadaptablepeople. The last stage of analysis consists ofre-reading these accounts from the perspectiveemphasizing structural factors in a ‘Gypsy fairfight’ explanation. The aim of the paper is to localizethe social experience of (insecurity in relationto the political order and social structure. Takingthem into account, we can aspire to sociologicallyrelevant knowledge of how security discoursesand practices shape our everyday ways of being.

  13. Numerical Analysis of In2S3 Layer Thickness, Band Gap and Doping Density for Effective Performance of a CIGS Solar Cell Using SCAPS

    Science.gov (United States)

    Khoshsirat, Nima; Md Yunus, Nurul Amziah

    2016-11-01

    The effect of indium sulfide buffer layer's geometrical and electro-optical properties on the Copper-Indium-Gallium-diSelenide solar cell performance using numerical simulation is investigated. The numerical simulation software used is a solar cell capacitance simulator in (SCAPS). The innermost impacts of buffer layer thickness, band gap, and doping density on the cells output parameters such as open circuit voltage, short circuit current density, fill factor, and the efficiency were extensively simulated. The results show that the cell efficiency, which was innovatively illustrated as a two-dimensional contour plot function, depends on the buffer layer electron affinity and doping density by keeping all the other parameters at a steady state. The analysis, which was made from this numerical simulation, has revealed that the optimum electron affinity is to be 4.25 ± 0.2 eV and donor density of the buffer layer is over 1× 10 ^{17} cm^{-3}. It is also shown that the cell with an optimum thin buffer layer has higher performance and efficiency due to the lower optical absorption of the buffer layer.

  14. Foundation: Transforming data bases into knowledge bases

    Science.gov (United States)

    Purves, R. B.; Carnes, James R.; Cutts, Dannie E.

    1987-01-01

    One approach to transforming information stored in relational data bases into knowledge based representations and back again is described. This system, called Foundation, allows knowledge bases to take advantage of vast amounts of pre-existing data. A benefit of this approach is inspection, and even population, of data bases through an intelligent knowledge-based front-end.

  15. First principles based multiparadigm modeling of electronic structures and dynamics

    Science.gov (United States)

    Xiao, Hai

    Electronic structures and dynamics are the key to linking the material composition and structure to functionality and performance. An essential issue in developing semiconductor devices for photovoltaics is to design materials with optimal band gaps and relative positioning of band levels. Approximate DFT methods have been justified to predict band gaps from KS/GKS eigenvalues, but the accuracy is decisively dependent on the choice of XC functionals. We show here for CuInSe2 and CuGaSe2, the parent compounds of the promising CIGS solar cells, conventional LDA and GGA obtain gaps of 0.0-0.01 and 0.02-0.24 eV (versus experimental values of 1.04 and 1.67 eV), while the historically first global hybrid functional, B3PW91, is surprisingly the best, with band gaps of 1.07 and 1.58 eV. Furthermore, we show that for 27 related binary and ternary semiconductors, B3PW91 predicts gaps with a MAD of only 0.09 eV, which is substantially better than all modern hybrid functionals, including B3LYP (MAD of 0.19 eV) and screened hybrid functional HSE06 (MAD of 0.18 eV). The laboratory performance of CIGS solar cells (> 20% efficiency) makes them promising candidate photovoltaic devices. However, there remains little understanding of how defects at the CIGS/CdS interface affect the band offsets and interfacial energies, and hence the performance of manufactured devices. To determine these relationships, we use the B3PW91 hybrid functional of DFT with the AEP method that we validate to provide very accurate descriptions of both band gaps and band offsets. This confirms the weak dependence of band offsets on surface orientation observed experimentally. We predict that the CBO of perfect CuInSe2/CdS interface is large, 0.79 eV, which would dramatically degrade performance. Moreover we show that band gap widening induced by Ga adjusts only the VBO, and we find that Cd impurities do not significantly affect the CBO. Thus we show that Cu vacancies at the interface play the key role in

  16. Relocating The 401st Tactical Fighter Wing

    Science.gov (United States)

    1991-05-03

    completed in 1996, although this date may slip to 1997 because of a temporary moratorium imposed by Congress. 2 1 7 This is not necessarily the case...bases such as Incirlik? Similar bases such as Izmir , Pirinclik, Cigli, or others, could present similar options, although Incirlik is the most...suggesting that the effects of inflation may be less significant than unpredictable fluctuations in exchange rates and changes in construction costs

  17. INVOLUTIVE BASES UNDER COMPOSITION

    Institute of Scientific and Technical Information of China (English)

    Zailiang TANG

    2007-01-01

    In this paper, the behaviors of involutive bases under composition operation are studied.For two kinds of involutive bases, i.e., Pommaret bases, Janet bases, we study their behavior problems under composition. Some further problems are also proposed.

  18. Regulation in the face of uncertainty: the evidence on electronic nicotine delivery systems (e-cigarettes).

    Science.gov (United States)

    Farsalinos, Konstantinos E; Le Houezec, Jacques

    2015-01-01

    Tobacco smoking is the largest single preventable cause of many chronic diseases and death. Effective treatments exist; however, few smokers use them and most try to quit by themselves. Most of the tobacco cigarette's toxicity is related to the combustion process. Models of harm reduction applied to tobacco suggest that switching from inhalation of combustible products to a noncombustible nicotine delivery product would likely result in a vast reduction in tobacco-related death and illness. Currently available evidence raises no doubt that electronic cigarettes (e-cigs) are by far less harmful than smoking (although probably not absolutely safe) and have the potential to be the most effective tobacco harm reduction products due to their unique property of resembling smoking and providing satisfaction to the user. A lot of controversy is surrounding e-cigs and their regulation, much of which is based on the precautionary principle. Although monitoring and further research is definitely needed, the arguments used to implement severe restrictions or bans are mostly hypothetical, weakly supported by evidence, and, in some cases, derived from mispresentation or misinterpretation of the study findings. Regulators should keep in mind that the target population is smokers who want to reduce or quit their deadly tobacco consumption. To achieve this goal, smokers should be honestly informed on the relative harmfulness of the different products. E-cigs are not tobacco products and are not used as medications. For this reason, a specific regulatory scheme is needed, separate from tobacco or medicinal products regulation. Regulation should implement specific quality criteria for products, rules for the exclusion of chemicals of reasonable concern, and appropriate testing for possible contaminants. Additionally, manufacturing standards derived from the food industry should be implemented and adjusted for specific conditions related to e-cigs. Finding the appropriate balance

  19. Filmes calcogenetos para células solares: crescimento e propriedades

    OpenAIRE

    Salomé, Pedro Manuel Parracho

    2011-01-01

    Thin film solar cells have in recent years gained market quota against traditional silicon photovoltaic panels. These developments were in a large part due to CdTe solar panels on whose development started earlier than their competitors. Panels based on Cu(In,Ga)Se2 (CIGS), despite being more efficient in a laboratory and industrial scale than the CdTe ones, still need a growth technology cheaper and easier to apply in industry. Although usually presented as a good candidate...

  20. Multilayer Transparent Top Electrode for Solution Processed Perovskite/Cu(In,Ga)(Se,S)2 Four Terminal Tandem Solar Cells.

    Science.gov (United States)

    Yang, Yang Michael; Chen, Qi; Hsieh, Yao-Tsung; Song, Tze-Bin; Marco, Nicholas De; Zhou, Huanping; Yang, Yang

    2015-07-28

    Halide perovskites (PVSK) have attracted much attention in recent years due to their high potential as a next generation solar cell material. To further improve perovskites progress toward a state-of-the-art technology, it is desirable to create a tandem structure in which perovskite may be stacked with a current prevailing solar cell such as silicon (Si) or Cu(In,Ga)(Se,S)2 (CIGS). The transparent top electrode is one of the key components as well as challenges to realize such tandem structure. Herein, we develop a multilayer transparent top electrode for perovskite photovoltaic devices delivering an 11.5% efficiency in top illumination mode. The transparent electrode is based on a dielectric/metal/dielectric structure, featuring an ultrathin gold seeded silver layer. A four terminal tandem solar cell employing solution processed CIGS and perovskite cells is also demonstrated with over 15% efficiency.

  1. Recent Progress in Nanoelectrical Characterizations of CdTe and Cu(In,Ga)Se2

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Chun-Sheng; To, Bobby; Glynn, Stephen; Mahabaduge, Hasitha; Barnes, Teresa; Al-Jassim, Mowafak M.

    2016-11-21

    We report two recent nanoelectrical characterizations of CdTe and Cu(In, Ga)Se2 (CIGS) thin-film solar cells by developing atomic force microscopy-based nanoelectrical probes. Charges trapped at defects at the CdS/CdTe interface were probed by Kelvin probe force microscopy (KPFM) potential mapping and by ion-milling the CdTe superstrate device in a bevel glancing angle of ~0.5 degrees. The results show randomly distributed donor-like defects at the interface. The effect of K post-deposition treatment on the near-surface region of the CIGS film was studied by KPFM potential and scanning spreading resistance microscopy (SSRM) resistivity mapping, which shows passivation of grain-boundary potential and improvement of resistivity uniformity by the K treatment.

  2. Towards sustainable photovoltaics: the search for new materials.

    Science.gov (United States)

    Peter, L M

    2011-05-13

    The opportunities for photovoltaic (PV) solar energy conversion are reviewed in the context of projected world energy demands for the twenty-first century. Conventional single-crystal silicon solar cells are facing increasingly strong competition from thin-film solar cells based primarily on polycrystalline absorber materials, such as cadmium telluride (CdTe) and copper indium gallium diselenide (CIGS). However, if PVs are to make a significant contribution to satisfy global energy requirements, issues of sustainability and cost will need to be addressed with increased urgency. There is a clear need to expand the range of materials and processes that is available for thin-film solar cell manufacture, placing particular emphasis on low-energy processing and sustainable non-toxic raw materials. The potential of new materials is exemplified by copper zinc tin sulphide, which is emerging as a viable alternative to the more toxic CdTe and the more expensive CIGS absorber materials.

  3. Impact of Cu-rich growth on the Cu2ZnSnSe4 surface morphology and related solar cells behavior

    Science.gov (United States)

    Ding, Sun; Yang, Ge; Li, Zhang; Shengzhi, Xu; Ze, Chen; Ning, Wang; Xuejiao, Liang; Changchun, Wei; Ying, Zhao; Xiaodan, Zhang

    2016-01-01

    In order to study the influence of Cu-rich growth on the performance of the Cu2ZnSnSe4 (CZTSe) thin film solar cells, a multi-stage co-evaporation process is applied. The CZTSe films are grown at a lower substrate temperature to reduce the existence time of Cux Sey at the first period caused by the volatility of SnSex. This study examines the surface morphology and device performance in Cu-rich growth and close-to-stoichiometric growth. Although the grain size of Cu-rich growth film increases a little, the difference was not dramatic as the results of CIGS reported previously. A model based on the grain boundary migration theory is proposed to explain the experimental results. The mechanisms of Cu-rich growth between CZTSe and CIGS might be different. Project supported by the Specialized Research Fund for the PhD Program of Higher Education (No. 20120031110039).

  4. Fiscal 1994 New Sunshine Program achievement report. Development of photovoltaic power generation system practicalization technology - Research on practicalization of thin-film solar cell manufacturing technology (Technology for higher quality - Development of CuInSe{sub 2} solar cell manufacturing technology); 1994 nendo taiyoko hatsuden system jitsuyoka gijutsu kaihatsu seika hokokusho. Usumaku taiyo denchi seizo gijutsu no jitsuyoka kenkyu (kohinshitsuka gijutsu (CuInSe{sub 2} taiyo denchi seizo no gijutsu kaihatsu))

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-03-01

    The aim is to develop solar cells that exhibit conversion efficiency of 12% in a 10cm times 10cm-large minimodule. When a substrate made of soda lime glass with an SiO{sub 2} coating thereon is used, high reproducibility is achieved in the manufacture of CuInSe{sub 2} (CIS) thin-film solar cells. For the manufacture of a high-quality Cu(InGa)Se{sub 2}(CIGS) light absorbing thin-film layer, it is necessary to develop high-quality precursor film manufacturing and gas phase selenization technologies. A laminated precursor film formed by sputtering is selenized in a H{sub 2}Se gas atmosphere for the formation of CuInSe{sub 2} and CIGS light absorbing thin-film layers, and 16 ZnO/CdS/CIS-structured thin film solar cells built into a 10cm times 10cm-large substrate exhibit conversion efficiency of 11.6%. A CIGS cell using a sulfur-containing Zn compound buffer layer exhibits conversion efficiency of 12.1%. Conditions for the manufacture of a ZnO:Al transparent conductive film are studied. Dependence of CIS-based solar cell output characteristics on temperature and irradiation may be compensated for under the JIS (Japanese Industrial Standard) compensatory formula. The CIS-based thin-film solar cell suffers but a little reduction in output due to temperature rise, and may be therefore said to be excellent. (NEDO)

  5. Cu(In,Ga)Se{sub 2} solar cells with double layered buffers grown by chemical bath deposition

    Energy Technology Data Exchange (ETDEWEB)

    Li, Z.Q.; Shi, J.H.; Zhang, D.W.; Liu, Q.Q.; Sun, Z.; Chen, Y.W. [Engineering Research Center for Nanophotonics and Advanced Instrument, Ministry of Education, Department of Physics, East China Normal University, North Zhongshan Rd. 3663, Shanghai 200062 (China); Yang, Z. [Key Laboratory for Thin Film and Microfabrication of the Ministry of Education, Research Institute of Micro/Nano Science and Technology, Shanghai Jiao Tong University, Shanghai 200240 (China); Huang, S.M., E-mail: engp5591@yahoo.com [Engineering Research Center for Nanophotonics and Advanced Instrument, Ministry of Education, Department of Physics, East China Normal University, North Zhongshan Rd. 3663, Shanghai 200062 (China)

    2011-10-31

    In based mixture In{sub x}(OH,S){sub y} buffer layers deposited by chemical bath deposition technique are a viable alternative to the traditional cadmium sulfide buffer layer in thin film solar cells. We report on the results of manipulating the absorber/buffer interface between the chalcopyrite Cu(In,Ga)Se{sub 2} (CIGS) absorber and CdS or ZnS buffer by addition of a thin In based mixture layer. It is shown that the presence of thin In{sub x}(OH,S){sub y} at the CIGS absorber/CdS or ZnS buffer interfaces greatly improve the solar cell performances. The performances of CIGS cells using dual buffer layers composed of In{sub x}(OH,S){sub y}/CdS or In{sub x}(OH,S){sub y}/ZnS increased by 22.4% and 51.6%, as compared to the single and standard CdS or ZnS buffered cells, respectively.

  6. Hybrid density functional theory study of Cu(In1−xGaxSe2 band structure for solar cell application

    Directory of Open Access Journals (Sweden)

    Xu-Dong Chen

    2014-08-01

    Full Text Available Cu(In1−xGaxSe2 (CIGS alloy based thin film photovoltaic solar cells have attracted more and more attention due to its large optical absorption coefficient, long term stability, low cost and high efficiency. However, the previous theoretical investigation of this material with first principle calculation cannot fulfill the requirement of experimental development, especially the accurate description of band structure and density of states. In this work, we use first principle calculation based on hybrid density functional theory to investigate the feature of CIGS, with B3LYP applied in the CuIn1−xGaxSe2 stimulation of the band structure and density of states. We report the simulation of the lattice parameter, band gap and chemical composition. The band gaps of CuGaSe2, CuIn0.25Ga0.75Se2, CuIn0.5Ga0.5Se2, CuIn0.75Ga0.25Se2 and CuInSe2 are obtained as 1.568 eV, 1.445 eV, 1.416 eV, 1.275 eV and 1.205 eV according to our calculation, which agree well with the available experimental values. The band structure of CIGS is also in accordance with the current theory.

  7. A dynamic knowledge base based search engine

    Institute of Scientific and Technical Information of China (English)

    WANG Hui-jin; HU Hua; LI Qing

    2005-01-01

    Search engines have greatly helped us to find thedesired information from the Intemet. Most search engines use keywords matching technique. This paper discusses a Dynamic Knowledge Base based Search Engine (DKBSE), which can expand the user's query using the keywords' concept or meaning. To do this, the DKBSE needs to construct and maintain the knowledge base dynamically via the system's searching results and the user's feedback information. The DKBSE expands the user's initial query using the knowledge base, and returns the searched information after the expanded query.

  8. Impact of secondary barriers on copper-indium-gallium-selenide solar-cell operation

    Science.gov (United States)

    Pudov, Alexei O.

    Thin-film solar cells based on CuInSe2 (CIS) absorber with a band gap of Eg = 1.0 eV and also based on CuIn1-x GaxSe2 (CIGS) alloy absorbers with a band-gap range of Eg = 1.0--1.67 eV are investigated in this work. Intermediate "buffer" semiconductor layers in p-n junctions of CIGS solar cells often improve photodiode properties of the devices. The primary goal of the thesis is to study secondary barriers in the conduction band at the buffer/absorber interface, which may limit current transport and thus reduce the efficiency of the solar cells. The secondary goal is to explore alternative wide-bandgap buffers in CIGS cell structures. CIGS cells with standard CdS buffer layers, and alternative ZnS(O,OH) and InS(O,OH) buffer layers were studied. CdS/CuIn1-xGaxSe2 solar cells with variable Ga content have a range of conduction-band offsets (DeltaEc) in the junction from moderately positive (spike offsets) in CdS/CuInSe2 to moderately negative (cliff offsets) in CdS/CuGaSe 2. Moderate conduction-band spikes in CdS/CIS and low-Ga CdS/CIGS are expected to cause distortions in diode current-voltage (J-V) curves of such solar cells under "red" illumination (hnu < Eg(buffer)); no J-V distortions are expected for high-Ga CdS/CIGS with cliff offsets. These predictions were confirmed in experiments: the distortions were absent for cells with Eg above 1.2--1.3 eV, at which CdS/CIGS DeltaE c is near zero. Experiments and numerical simulations showed that one approach to reduce secondary barriers and J-V distortions in low-Ga high-spike cells is to thin the buffer layer(s). Blue photons (hnu above Eg(buffer)) in the solar spectrum induce photoconductivity in the otherwise compensated buffers, which also results in lowering of the secondary barriers. It was shown that CIGS cells with CdS, InS(O,OH), and ZnS(O,OH) buffers have a similar response to "blue" photons: J-V distortion, if present under red light, is reduced or entirely disappears with blue-light exposure within minutes

  9. Solid Base Catalysis

    CERN Document Server

    Ono, Yoshio

    2011-01-01

    The importance of solid base catalysts has come to be recognized for their environmentally benign qualities, and much significant progress has been made over the past two decades in catalytic materials and solid base-catalyzed reactions. The book is focused on the solid base. Because of the advantages over liquid bases, the use of solid base catalysts in organic synthesis is expanding. Solid bases are easier to dispose than liquid bases, separation and recovery of products, catalysts and solvents are less difficult, and they are non-corrosive. Furthermore, base-catalyzed reactions can be performed without using solvents and even in the gas phase, opening up more possibilities for discovering novel reaction systems. Using numerous examples, the present volume describes the remarkable role solid base catalysis can play, given the ever increasing worldwide importance of "green" chemistry. The reader will obtain an overall view of solid base catalysis and gain insight into the versatility of the reactions to whic...

  10. Development of process technology for large-area thin-film solar modules based on compound semiconductors. Final report; Entwicklung der technologischen Grundlagen fuer grosse Photovoltaikmodule auf Basis von Duennschicht-Verbindungshalbleitern. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Maurus, H.; Lechner, P.; Geyer, R.; Ruebel, H.; Schade, H.; Psyk, W.; Frammelsberger, W.; Berthold, W.; Eichner, C.; Heckel, E.; Huber, R.; Labudde-Eibl, H.; Raith, S.; Schenk, B.; Ullrich, H.

    1998-06-01

    A cooperative effort of the Center for Solar Energy and Hydrogen Research (ZSW) and Phototronics Solartechnik GmbH (PST) aimed at the transfer of highly efficient solar cells developed on a laboratory scale, to large-area thin-film solar modules suitable for production. This work was based on research and development at the Institute for Physical Electronics (IPE) of Stuttgart University and ZSW on one hand, and on the know-how of PST in regard to large-area module fabrication on the other hand. The various thin-film layers of the cells and modules comprize molybdenum as rear contact, copper-indium(gallium)-diselenide (CIGS) as absorber material, the combination of cadmium sulphide (CdS) and ZnO as window layer. To produce these layers on large areas (30x30 cm{sup 2}), equipment was constructed and procedures were developed. Monolithic series connection of cells, used in other thin-film technologies, was studied and optimized by suitable patterning procedures, such as laser-scribing, mechanical scribing or lift-off techniques. Central to the PST efforts was the large-area deposition of Mo followed by patterning for the monolithic series connection, and furthermore important contributions in regard to the ZnO window layer as well as aspects of the module technology. The latter include film removal along the module edges, contacting and cable attachment, lamination, module measurements and temperature/humidity tests. The main goal, namely the basic development of equipment and procedures to fabricate large-area (30x30 cm{sup 2}) modules with an efficiency of 10-12%, was reached (best module with 11.7% efficiency referenced to the aperature area). (orig.) [Deutsch] Um die im Labormassstab entwickelten hocheffizienten Solarzellen in industriell relevante grossflaechige Duennschichtmodule umzusetzen, arbeiteten das Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung (ZSW) Baden-Wuerttemberg und die Phototronics Solartechnik GmbH (PST) zusammen. Ausgangsbasis waren

  11. Manufacturable CuIn(Ga)Se{sub 2}-based solar cells via development of co-sputtered CuInSe{sub 2} absorber layers

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Ingrid Eisgruber

    1999-03-20

    Yield and reproducibility remain issues in CuIn(Ga)Se{sub 2} (CIGS) photovoltaic module fabrication. While small-area cells (<1 cm{sup 2}) over 18% efficient have been reported, the best large-area manufactured devices (>1 ft{sup 2}) are 11% efficient with about 60% yield. If improvements in large-area manufacturing can accomplish 15% efficiency and 90% yield, the result is a doubling in throughput leading to a reduction in cost per watt of over 50%. The challenge now facing the photovoltaics industry is to bring the efficiencies of small-area cells and large-area industrial modules closer together and to raise manufacturing yields.

  12. Systematic ab initio study of half-Heusler materials for optoelectronic applications

    Energy Technology Data Exchange (ETDEWEB)

    Gruhn, Thomas; Felser, Claudia [Institute of Inorganic and Analytical Chemistry, Johannes Gutenberg University, Mainz (Germany)

    2010-07-01

    The development of new, optimized optoelectronic devices depends crucially on the availability of semiconductors with taylored electronic and structural properties. At the moment, the majority of applications is based on a rather small set of semiconducting materials, while many more semiconductors exist in the huge class of ternary compounds. Especially, the class of 8-electron half-Heusler materials comprises a large number semiconducters with various properties. With the help of ab initio density functional theory we have studied essentially all 8-electron half-Heusler compounds that are of technological relevance. For more than 650 compounds we have determined the optimum configuration by varying the lattice constant and permuting the elements over the sublattices. Within this exceptionally large data set we have studied the band structure and the lattice constants as a function of the electronegativities of the elements, the arrangement of the atoms, and the atomic radii. The results are used to select suitable materials for the buffer layer in thin-film solar cells with a Cu(In,Ga)Se{sub 2} (CIGS) absorber layer. Considering the bandgap and the geometrical matching with the CIGS film, we have obtained a set of 29 compounds that are promissing materials for cadmium-free CIGS buffer layer.

  13. Nanosecond laser-induced selective removal of the active layer of CuInGaSe2 solar cells by stress-assisted ablation

    Science.gov (United States)

    Buzás, András; Geretovszky, Zsolt

    2012-06-01

    We demonstrate that laser pulses of nanosecond duration (λ=1064 nm, τ=25 ns, PRR =5 kHz) are capable of the clean removal of the CuInGaSe2 (CIGS) and ZnO:Al layers in the layer structure of chalcogenide-based solar cells, leaving the underlying Mo layer undamaged and producing excellent crater morphology. Our results prove that the material removal process is governed by the thermomechanical stress developing in the CIGS layer due to rapid laser heating. In the mechanical ablation of the active layer, three phenomena play a crucial role, namely, delamination, buckling, and fracture. Morphological and compositional analysis of the laser-processed areas is used to identify the experimental parameters where clean mechanical ablation can be achieved. Numerical calculations, performed in the comsol software environment, are also presented to complement the experimental tendencies and verify the proposed model. Our calculation proves the development of a stress distribution that drives the delamination of the CIGS and Mo layers. As the delamination front proceeds radially outward, the separation of the layers ceases in the colder outer regions according to the Griffith's criterion and defines the size of the craters produced afterwards. The free-standing chalcogenide layer continues to deform, and buckling results in a growing tensile stress at the perimeter of the delaminated area, where ultimately fracture will finalize the removal process and facilitate the clean ablation of the laser-irradiated area.

  14. Knowledge Based Strategies for Knowledge Based Organizations

    OpenAIRE

    2012-01-01

    In the present, we can observe that a new economy is arising. It is an economy based on knowledge and ideas, in which the key factor for prosperity and for creation of the new jobs is the knowledge capitalization. Knowledge capitalization, intellectual capital, obtaining prosperity in the market economy imposes a new terminology, new managerial methods and techniques, new technologies and also new strategies. In other words, knowledge based economy, as a new type of economy; impose a new type...

  15. Mobile Inquiry Based Learning

    OpenAIRE

    Specht, Marcus

    2012-01-01

    Specht, M. (2012, 8 November). Mobile Inquiry Based Learning. Presentation given at the Workshop "Mobile inquiry-based learning" at the Mobile Learning Day 2012 at the Fernuniversität Hagen, Hagen, Germany.

  16. VectorBase

    Data.gov (United States)

    U.S. Department of Health & Human Services — VectorBase is a Bioinformatics Resource Center for invertebrate vectors. It is one of four Bioinformatics Resource Centers funded by NIAID to provide web-based...

  17. "Education-based Research"

    DEFF Research Database (Denmark)

    Degn Johansson, Troels

    This paper lays out a concept of education-based research-the production of research knowledge within the framework of tertiary design education-as an integration of problem-based learning and research-based education. This leads to a critique of reflective practice as the primary way to facilitate...... learning at this level, a discussion of the nature of design problems in the instrumentalist tradition, and some suggestions as to how design studies curricula may facilitate education-based research....

  18. Convergent Filter Bases

    Directory of Open Access Journals (Sweden)

    Coghetto Roland

    2015-09-01

    Full Text Available We are inspired by the work of Henri Cartan [16], Bourbaki [10] (TG. I Filtres and Claude Wagschal [34]. We define the base of filter, image filter, convergent filter bases, limit filter and the filter base of tails (fr: filtre des sections.

  19. Convergent Filter Bases

    OpenAIRE

    Coghetto Roland

    2015-01-01

    We are inspired by the work of Henri Cartan [16], Bourbaki [10] (TG. I Filtres) and Claude Wagschal [34]. We define the base of filter, image filter, convergent filter bases, limit filter and the filter base of tails (fr: filtre des sections).

  20. Design and realization of transparent solar modules based on luminescent solar concentrators integrating nanostructured photonic crystals

    Science.gov (United States)

    Jiménez‐Solano, Alberto; Delgado‐Sánchez, José‐Maria; Calvo, Mauricio E.; Miranda‐Muñoz, José M.; Lozano, Gabriel; Sancho, Diego; Sánchez‐Cortezón, Emilio

    2015-01-01

    Abstract Herein, we present a prototype of a photovoltaic module that combines a luminescent solar concentrator integrating one‐dimensional photonic crystals and in‐plane CuInGaSe2 (CIGS) solar cells. Highly uniform and wide‐area nanostructured multilayers with photonic crystal properties were deposited by a cost‐efficient and scalable liquid processing amenable to large‐scale fabrication. Their role is to both maximize light absorption in the targeted spectral range, determined by the fluorophore employed, and minimize losses caused by emission at angles within the escape cone of the planar concentrator. From a structural perspective, the porous nature of the layers facilitates the integration with the thermoplastic polymers typically used to encapsulate and seal these modules. Judicious design of the module geometry, as well as of the optical properties of the dielectric mirrors employed, allows optimizing light guiding and hence photovoltaic performance while preserving a great deal of transparency. Optimized in‐plane designs like the one herein proposed are of relevance for building integrated photovoltaics, as ease of fabrication, long‐term stability and improved performance are simultaneously achieved. © 2015 The Authors. Progress in Photovoltaics: Research and Applications published by John Wiley & Sons Ltd. PMID:27656090

  1. Pattern Based Morphometry

    OpenAIRE

    Gaonkar, Bilwaj; Pohl, Kilian; Davatzikos, Christos

    2011-01-01

    Voxel based morphometry (VBM) is widely used in the neuroimaging community to infer group differences in brain morphology. VBM is effective in quantifying group differences highly localized in space. However it is not equally effective when group differences might be based on interactions between multiple brain networks. We address this by proposing a new framework called pattern based morphometry (PBM). PBM is a data driven technique. It uses a dictionary learning algorithm to extract global...

  2. Imagery Data Base Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Imagery Data Base Facility supports AFRL and other government organizations by providing imagery interpretation and analysis to users for data selection, imagery...

  3. Synthetic Base Fluids

    Science.gov (United States)

    Brown, M.; Fotheringham, J. D.; Hoyes, T. J.; Mortier, R. M.; Orszulik, S. T.; Randles, S. J.; Stroud, P. M.

    The chemical nature and technology of the main synthetic lubricant base fluids is described, covering polyalphaolefins, alkylated aromatics, gas-to-liquid (GTL) base fluids, polybutenes, aliphatic diesters, polyolesters, polyalkylene glycols or PAGs and phosphate esters.Other synthetic lubricant base oils such as the silicones, borate esters, perfluoroethers and polyphenylene ethers are considered to have restricted applications due to either high cost or performance limitations and are not considered here.Each of the main synthetic base fluids is described for their chemical and physical properties, manufacture and production, their chemistry, key properties, applications and their implications when used in the environment.

  4. Case-based reasoning

    CERN Document Server

    Kolodner, Janet

    1993-01-01

    Case-based reasoning is one of the fastest growing areas in the field of knowledge-based systems and this book, authored by a leader in the field, is the first comprehensive text on the subject. Case-based reasoning systems are systems that store information about situations in their memory. As new problems arise, similar situations are searched out to help solve these problems. Problems are understood and inferences are made by finding the closest cases in memory, comparing and contrasting the problem with those cases, making inferences based on those comparisons, and asking questions whe

  5. Soy-based polyols

    Science.gov (United States)

    Suppes, Galen; Lozada, Zueica; Lubguban, Arnold

    2013-06-25

    The invention provides processes for preparing soy-based oligomeric polyols or substituted oligomeric polyols, as well as urethane bioelasteromers comprising the oligomeric polyols or substituted oligomeric polyols.

  6. Monitoring Knowledge Base (MKB)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Monitoring Knowledge Base (MKB) is a compilation of emissions measurement and monitoring techniques associated with air pollution control devices, industrial...

  7. Empirically Based, Agent-based models

    Directory of Open Access Journals (Sweden)

    Elinor Ostrom

    2006-12-01

    Full Text Available There is an increasing drive to combine agent-based models with empirical methods. An overview is provided of the various empirical methods that are used for different kinds of questions. Four categories of empirical approaches are identified in which agent-based models have been empirically tested: case studies, stylized facts, role-playing games, and laboratory experiments. We discuss how these different types of empirical studies can be combined. The various ways empirical techniques are used illustrate the main challenges of contemporary social sciences: (1 how to develop models that are generalizable and still applicable in specific cases, and (2 how to scale up the processes of interactions of a few agents to interactions among many agents.

  8. Model-based geostatistics

    CERN Document Server

    Diggle, Peter J

    2007-01-01

    Model-based geostatistics refers to the application of general statistical principles of modeling and inference to geostatistical problems. This volume provides a treatment of model-based geostatistics and emphasizes on statistical methods and applications. It also features analyses of datasets from a range of scientific contexts.

  9. Game-Based Teaching

    DEFF Research Database (Denmark)

    Hanghøj, Thorkild

    2013-01-01

    This chapter outlines theoretical and empirical perspectives on how Game-Based Teaching can be integrated within the context of formal schooling. Initially, this is done by describing game scenarios as models for possible actions that need to be translated into curricular knowledge practices...... approaches to game-based teaching, which may or may not correspond with the pedagogical models of particular games....

  10. Secure base stations

    NARCIS (Netherlands)

    Bosch, Peter; Brusilovsky, Alec; McLellan, Rae; Mullender, Sape; Polakos, Paul

    2009-01-01

    With the introduction of the third generation (3G) Universal Mobile Telecommunications System (UMTS) base station router (BSR) and fourth generation (4G) base stations, such as the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) Evolved Node B (eNB), it has become important to se

  11. Hydrogel based occlusion systems

    NARCIS (Netherlands)

    Stam, F.A.; Jackson, N.; Dubruel, P.; Adesanya, K.; Embrechts, A.; Mendes, E.; Neves, H.P.; Herijgers, P.; Verbrugghe, Y.; Shacham, Y.; Engel, L.; Krylov, V.

    2013-01-01

    A hydrogel based occlusion system, a method for occluding vessels, appendages or aneurysms, and a method for hydrogel synthesis are disclosed. The hydrogel based occlusion system includes a hydrogel having a shrunken and a swollen state and a delivery tool configured to deliver the hydrogel to a tar

  12. Revolutionary Base Spurs Development

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    MAO Zedong’s Autumn Harvest Uprising spurred not only revolution but development and innovation among the masses. In October 1927, Mao Zedong led troops to Jinggang Mountain, establishing the first revolutionary base. During the 1960s, many young people went to work at Jinggang Mountain and devoted their youth to this revolutionary base. The open-minded and shrewd Tong

  13. Diffusion Based Photon Mapping

    DEFF Research Database (Denmark)

    Schjøth, Lars; Olsen, Ole Fogh; Sporring, Jon

    2006-01-01

    . To address this problem we introduce a novel photon mapping algorithm based on nonlinear anisotropic diffusion. Our algorithm adapts according to the structure of the photon map such that smoothing occurs along edges and structures and not across. In this way we preserve the important illumination features......, while eliminating noise. We call our method diffusion based photon mapping....

  14. Diffusion Based Photon Mapping

    DEFF Research Database (Denmark)

    Schjøth, Lars; Fogh Olsen, Ole; Sporring, Jon

    2007-01-01

    . To address this problem we introduce a novel photon mapping algorithm based on nonlinear anisotropic diffusion. Our algorithm adapts according to the structure of the photon map such that smoothing occurs along edges and structures and not across. In this way we preserve the important illumination features......, while eliminating noise. We call our method diffusion based photon mapping....

  15. Content-Based Instruction

    Science.gov (United States)

    DelliCarpini, M.; Alonso, O.

    2013-01-01

    DelliCarpini and Alonso's book "Content-Based Instruction" explores different approaches to teaching content-based instruction (CBI) in the English language classroom. They provide a comprehensive overview of how to teach CBI in an easy-to-follow guide that language teachers will find very practical for their own contexts. Topics…

  16. Skull base tumours

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Alexandra [Instituto Portugues de Oncologia Francisco Gentil, Servico de Radiologia, Rua Professor Lima Basto, 1093 Lisboa Codex (Portugal)], E-mail: borgesalexandra@clix.pt

    2008-06-15

    With the advances of cross-sectional imaging radiologists gained an increasing responsibility in the management of patients with skull base pathology. As this anatomic area is hidden to clinical exam, surgeons and radiation oncologists have to rely on imaging studies to plan the most adequate treatment. To fulfil these endeavour radiologists need to be knowledgeable about skull base anatomy, about the main treatment options available, their indications and contra-indications and needs to be aware of the wide gamut of pathologies seen in this anatomic region. This article will provide a radiologists' friendly approach to the central skull base and will review the most common central skull base tumours and tumours intrinsic to the bony skull base.

  17. Layer-by-Layer Nanoassembly of Copper Indium Gallium Selenium Nanoparticle Films for Solar Cell Applications

    Directory of Open Access Journals (Sweden)

    A. Hemati

    2012-01-01

    Full Text Available Thin films of CIGS nanoparticles interdigited with polymers have been fabricated through a cost-effective nonvacuum film deposition process called layer-by-layer (LbL nanoassembly. CIGS nanoparticles synthesized by heating copper chloride, indium chloride, gallium chloride, and selenium in oleylamine were dispersed in water, and desired surface charges were obtained through pH regulation and by coating the particles with polystyrene sulfonate (PSS. Raising the pH of the nanoparticle dispersion reduced the zeta-potential from +61 mV at pH 7 to −51 mV at pH 10.5. Coating the CIGS nanoparticles with PSS (CIGS-PSS produced a stable dispersion in water with −56.9 mV zeta-potential. Thin films of oppositely charged CIGS nanoparticles (CIGS/CIGS, CIGS nanoparticles and PSS (CIGS/PSS, and PSS-coated CIGS nanoparticles and polyethylenimine (CIGS-PSS/PEI were constructed through the LbL nanoassembly. Film thickness and resistivity of each bilayer of the films were measured, and photoelectric properties of the films were studied for solar cell applications. Solar cell devices fabricated with a 219 nm CIGS film, when illuminated by 50 W light-source, produced 0.7 V open circuit voltage and 0.3 mA/cm2 short circuit current density.

  18. Pattern based morphometry.

    Science.gov (United States)

    Gaonkar, Bilwaj; Pohl, Kilian; Davatzikos, Christos

    2011-01-01

    Voxel based morphometry (VBM) is widely used in the neuroimaging community to infer group differences in brain morphology. VBM is effective in quantifying group differences highly localized in space. However it is not equally effective when group differences might be based on interactions between multiple brain networks. We address this by proposing a new framework called pattern based morphometry (PBM). PBM is a data driven technique. It uses a dictionary learning algorithm to extract global patterns that characterize group differences. We test this approach on simulated and real data obtained from ADNI. In both cases PBM is able to uncover complex global patterns effectively.

  19. QuickBase

    CERN Document Server

    Conner, Nancy

    2007-01-01

    Ready to put Intuit's QuickBase to work? Our new Missing Manual shows you how to capture, modify, share, and manage data and documents with this web-based data-sharing program quickly and easily. No longer do you have to coordinate your team through a blizzard of emails or play frustrating games of "guess which document is the right one."QuickBase saves your organization time and money, letting you manage and share the information that makes your business tick: sales figures, project timelines, drafts of documents, purchase or work requests--whatever information you need to keep business flowi

  20. Skull Base Anatomy.

    Science.gov (United States)

    Patel, Chirag R; Fernandez-Miranda, Juan C; Wang, Wei-Hsin; Wang, Eric W

    2016-02-01

    The anatomy of the skull base is complex with multiple neurovascular structures in a small space. Understanding all of the intricate relationships begins with understanding the anatomy of the sphenoid bone. The cavernous sinus contains the carotid artery and some of its branches; cranial nerves III, IV, VI, and V1; and transmits venous blood from multiple sources. The anterior skull base extends to the frontal sinus and is important to understand for sinus surgery and sinonasal malignancies. The clivus protects the brainstem and posterior cranial fossa. A thorough appreciation of the anatomy of these various areas allows for endoscopic endonasal approaches to the skull base.

  1. Data base management study

    Science.gov (United States)

    1976-01-01

    Data base management techniques and applicable equipment are described. Recommendations which will assist potential NASA data users in selecting and using appropriate data base management tools and techniques are presented. Classes of currently available data processing equipment ranging from basic terminals to large minicomputer systems were surveyed as they apply to the needs of potential SEASAT data users. Cost and capabilities projections for this equipment through 1985 were presented. A test of a typical data base management system was described, as well as the results of this test and recommendations to assist potential users in determining when such a system is appropriate for their needs. The representative system tested was UNIVAC's DMS 1100.

  2. Lidar base specification

    Science.gov (United States)

    Heidemann, Hans Karl.

    2012-01-01

    In late 2009, a $14.3 million allocation from the “American Recovery and Reinvestment Act” for new light detection and ranging (lidar) elevation data prompted the U.S. Geological Survey (USGS) National Geospatial Program (NGP) to develop a common base specification for all lidar data acquired for The National Map. Released as a draft in 2010 and formally published in 2012, the USGS–NGP “Lidar Base Specification Version 1.0” (now Lidar Base Specification) was quickly embraced as the foundation for numerous state, county, and foreign country lidar specifications.

  3. Cheboygan Vessel Base

    Data.gov (United States)

    Federal Laboratory Consortium — Cheboygan Vessel Base (CVB), located in Cheboygan, Michigan, is a field station of the USGS Great Lakes Science Center (GLSC). CVB was established by congressional...

  4. BaseMap

    Data.gov (United States)

    California Department of Resources — The goal of this project is to provide a convenient base map that can be used as a starting point for CA projects. It's simple, but designed to work at a number of...

  5. Mutually unbiased bases

    Indian Academy of Sciences (India)

    S Chaturvedi

    2002-08-01

    After a brief review of the notion of a full set of mutually unbiased bases in an -dimensional Hilbert space, we summarize the work of Wootters and Fields (W K Wootters and B C Fields, Ann. Phys. 191, 363 (1989)) which gives an explicit construction for such bases for the case = r, where is a prime. Further, we show how, by exploiting certain freedom in the Wootters–Fields construction, the task of explicitly writing down such bases can be simplified for the case when is an odd prime. In particular, we express the results entirely in terms of the character vectors of the cyclic group of order . We also analyse the connection between mutually unbiased bases and the representations of .

  6. Kelomehele preemia Baseli festivalil

    Index Scriptorium Estoniae

    2000-01-01

    Baselis festivalil "VIPER - International Festival for Film Video and New Media" tunnistati parimaks CD-ROMiks Gustav Deutschi/Anna Schimeki "Odysee today", netiprojektiks itaallaste "01.ORG", äramärkimispreemia - Raivo Kelomehe "Videoweaver"

  7. WormBase

    Data.gov (United States)

    U.S. Department of Health & Human Services — WormBase is an international consortium of biologists and computer scientists dedicated to providing the research community with accurate, current, accessible...

  8. Layered nickel based superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Ronning, Filip [Los Alamos National Laboratory; Bauer, Eric D [Los Alamos National Laboratory; Park, Tuson [Los Alamos National Laboratory; Kurita, Nobuyuki [Los Alamos National Laboratory; Klimczuk, T [Los Alamos National Laboratory; Movshovich, R [Los Alamos National Laboratory; Thompson, J D [Los Alamos National Laboratory; Sefat, A S [ORNL; Mandrus, D [ORNL

    2009-01-01

    We review the properties of Ni-based superconductors which contain Ni{sub 2}X{sub 2} (X=As, P, Bi, Si, Ge, B) planes, a common structural element to the recently discovered FeAs superconductors. We also compare the properties ofthe Ni-and Fe-based systems from a perspective ofelectronic structure as well as structure-property relations.

  9. Participatory design based research

    DEFF Research Database (Denmark)

    Dau, Susanne; Bach Jensen, Louise; Falk, Lars

    2014-01-01

    This poster reveal how participatory design based research by the use of a CoED inspired creative process can be used for designing solutions to problems regarding students study activities outside campus.......This poster reveal how participatory design based research by the use of a CoED inspired creative process can be used for designing solutions to problems regarding students study activities outside campus....

  10. REST based mobile applications

    Science.gov (United States)

    Rambow, Mark; Preuss, Thomas; Berdux, Jörg; Conrad, Marc

    2008-02-01

    Simplicity is the major advantage of REST based webservices. Whereas SOAP is widespread in complex, security sensitive business-to-business aplications, REST is widely used for mashups and end-user centric applicatons. In that context we give an overview of REST and compare it to SOAP. Furthermore we apply the GeoDrawing application as an example for REST based mobile applications and emphasize on pros and cons for the use of REST in mobile application scenarios.

  11. DSP Based Waveform Generator

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The DSP Based Waveform Generator is used for CSR Control system to control special controlled objects, such as the pulsed power supply for magnets, RF system, injection and extraction synchronization, global CSR synchronization etc. This intelligent controller based on 4800 MIPS DSP and 256M SDRAM technology will supply highly stable and highly accurate reference waveform used by the power supply of magnets. The specifications are as follows:

  12. Hydrogel based occlusion systems

    OpenAIRE

    Stam, F.A.; Jackson, N.; Dubruel, P.; Adesanya, K.; Embrechts, A; Mendes, E.; Neves, H.P.; Herijgers, P; Verbrugghe, Y.; Shacham, Y.; Engel, L.; Krylov, V

    2013-01-01

    A hydrogel based occlusion system, a method for occluding vessels, appendages or aneurysms, and a method for hydrogel synthesis are disclosed. The hydrogel based occlusion system includes a hydrogel having a shrunken and a swollen state and a delivery tool configured to deliver the hydrogel to a target occlusion location. The hydrogel is configured to permanently occlude the target occlusion location in the swollen state. The hydrogel may be an electro-activated hydrogel (EAH) which could be ...

  13. Electrochemical Based Biosensors

    OpenAIRE

    Chung Chiun Liu

    2012-01-01

    This editorial summarizes the general approaches of the electrochemical based biosensors described in the manuscripts published in this Special Issue. Electrochemical based biosensors are scientifically and economically important for the detection and early diagnosis of many diseases, and they will be increasing used and developed in the coming years. The importance of the selection of recognition processes, fabrication techniques and biosensor materials will be introduced.

  14. Base de datos FIA

    OpenAIRE

    Clemente Iturriaga, José Alfredo

    2015-01-01

    Este trabajo se basa en el desarrollo de una base de datos en Oracle para la FIA (Federación Internacional de Automovilismo) partiendo de cero. Aquest treball es basa en el desenvolupament d'una base de dades en Oracle per a la FIA (Federació Internacional d'Automobilisme) partint de zero. Bachelor thesis for the Computer Science program on Databases.

  15. Swarm-based medicine.

    Science.gov (United States)

    Putora, Paul Martin; Oldenburg, Jan

    2013-09-19

    Occasionally, medical decisions have to be taken in the absence of evidence-based guidelines. Other sources can be drawn upon to fill in the gaps, including experience and intuition. Authorities or experts, with their knowledge and experience, may provide further input--known as "eminence-based medicine". Due to the Internet and digital media, interactions among physicians now take place at a higher rate than ever before. With the rising number of interconnected individuals and their communication capabilities, the medical community is obtaining the properties of a swarm. The way individual physicians act depends on other physicians; medical societies act based on their members. Swarm behavior might facilitate the generation and distribution of knowledge as an unconscious process. As such, "swarm-based medicine" may add a further source of information to the classical approaches of evidence- and eminence-based medicine. How to integrate swarm-based medicine into practice is left to the individual physician, but even this decision will be influenced by the swarm.

  16. LDEF materials data bases

    Science.gov (United States)

    Funk, Joan G.; Strickland, John W.; Davis, John M.

    1993-01-01

    The Long Duration Exposure Facility (LDEF) and the accompanying experiments were composed of and contained a wide variety of materials representing the largest collection of materials flown in low Earth orbit (LEO) and retrieved for ground based analysis to date. The results and implications of the mechanical, thermal, optical, and electrical data from these materials are the foundation on which future LEO space missions will be built. The LDEF Materials Special Investigation Group (MSIG) has been charged with establishing and developing data bases to document these materials and their performance to assure not only that the data are archived for future generations but also that the data are available to the spacecraft user community in an easily accessed, user-friendly form. This paper discusses the format and content of the three data bases developed or being developed to accomplish this task. The hardware and software requirements for each of these three data bases are discussed along with current availability of the data bases. This paper also serves as a user's guide to the MAPTIS LDEF Materials Data Base.

  17. Couches minces de chalcogénures de zinc déposées par spray-CVD assisté par rayonnement infrarouge pour des applications photovoltaïques

    OpenAIRE

    FROGER, Vincent

    2012-01-01

    In the field of photovoltaic devices, organic and CIGS-based solar cells are both promising way to compete with silicon-based technologies for low and high power generation. In order to provide safe and cost-effective thin films for these devices, zinc chalcogenides layers represent interesting opportunities to replace indium (expensive) and cadmium-based (toxic) layers. Semiconductors like Zn1-xMgxO and ZnS had been synthesized using an infrared assisted spray-CVD apparatus. The interaction ...

  18. Exposure to electronic cigarettes impairs pulmonary anti-bacterial and anti-viral defenses in a mouse model.

    Directory of Open Access Journals (Sweden)

    Thomas E Sussan

    Full Text Available Electronic cigarettes (E-cigs have experienced sharp increases in popularity over the past five years due to many factors, including aggressive marketing, increased restrictions on conventional cigarettes, and a perception that E-cigs are healthy alternatives to cigarettes. Despite this perception, studies on health effects in humans are extremely limited and in vivo animal models have not been generated. Presently, we determined that E-cig vapor contains 7 x 10(11 free radicals per puff. To determine whether E-cig exposure impacts pulmonary responses in mice, we developed an inhalation chamber for E-cig exposure. Mice that were exposed to E-cig vapor contained serum cotinine concentrations that are comparable to human E-cig users. E-cig exposure for 2 weeks produced a significant increase in oxidative stress and moderate macrophage-mediated inflammation. Since, COPD patients are susceptible to bacterial and viral infections, we tested effects of E-cigs on immune response. Mice that were exposed to E-cig vapor showed significantly impaired pulmonary bacterial clearance, compared to air-exposed mice, following an intranasal infection with Streptococcus pneumonia. This defective bacterial clearance was partially due to reduced phagocytosis by alveolar macrophages from E-cig exposed mice. In response to Influenza A virus infection, E-cig exposed mice displayed increased lung viral titers and enhanced virus-induced illness and mortality. In summary, this study reports a murine model of E-cig exposure and demonstrates that E-cig exposure elicits impaired pulmonary anti-microbial defenses. Hence, E-cig exposure as an alternative to cigarette smoking must be rigorously tested in users for their effects on immune response and susceptibility to bacterial and viral infections.

  19. Exposure to electronic cigarettes impairs pulmonary anti-bacterial and anti-viral defenses in a mouse model.

    Science.gov (United States)

    Sussan, Thomas E; Gajghate, Sachin; Thimmulappa, Rajesh K; Ma, Jinfang; Kim, Jung-Hyun; Sudini, Kuladeep; Consolini, Nicola; Cormier, Stephania A; Lomnicki, Slawo; Hasan, Farhana; Pekosz, Andrew; Biswal, Shyam

    2015-01-01

    Electronic cigarettes (E-cigs) have experienced sharp increases in popularity over the past five years due to many factors, including aggressive marketing, increased restrictions on conventional cigarettes, and a perception that E-cigs are healthy alternatives to cigarettes. Despite this perception, studies on health effects in humans are extremely limited and in vivo animal models have not been generated. Presently, we determined that E-cig vapor contains 7 x 10(11) free radicals per puff. To determine whether E-cig exposure impacts pulmonary responses in mice, we developed an inhalation chamber for E-cig exposure. Mice that were exposed to E-cig vapor contained serum cotinine concentrations that are comparable to human E-cig users. E-cig exposure for 2 weeks produced a significant increase in oxidative stress and moderate macrophage-mediated inflammation. Since, COPD patients are susceptible to bacterial and viral infections, we tested effects of E-cigs on immune response. Mice that were exposed to E-cig vapor showed significantly impaired pulmonary bacterial clearance, compared to air-exposed mice, following an intranasal infection with Streptococcus pneumonia. This defective bacterial clearance was partially due to reduced phagocytosis by alveolar macrophages from E-cig exposed mice. In response to Influenza A virus infection, E-cig exposed mice displayed increased lung viral titers and enhanced virus-induced illness and mortality. In summary, this study reports a murine model of E-cig exposure and demonstrates that E-cig exposure elicits impaired pulmonary anti-microbial defenses. Hence, E-cig exposure as an alternative to cigarette smoking must be rigorously tested in users for their effects on immune response and susceptibility to bacterial and viral infections.

  20. On mutually unbiased bases

    CERN Document Server

    Durt, Thomas; Bengtsson, Ingemar; Zyczkowski, Karol \\

    2010-01-01

    Mutually unbiased bases for quantum degrees of freedom are central to all theoretical investigations and practical exploitations of complementary properties. Much is known about mutually unbiased bases, but there are also a fair number of important questions that have not been answered in full as yet. In particular, one can find maximal sets of ${N+1}$ mutually unbiased bases in Hilbert spaces of prime-power dimension ${N=p^\\m}$, with $p$ prime and $\\m$ a positive integer, and there is a continuum of mutually unbiased bases for a continuous degree of freedom, such as motion along a line. But not a single example of a maximal set is known if the dimension is another composite number ($N=6,10,12,...$). In this review, we present a unified approach in which the basis states are labeled by numbers ${0,1,2,...,N-1}$ that are both elements of a Galois field and ordinary integers. This dual nature permits a compact systematic construction of maximal sets of mutually unbiased bases when they are known to exist but th...

  1. Design-Based Research

    DEFF Research Database (Denmark)

    Gynther, Karsten; Christensen, Ove; Petersen, Trine Brun

    2012-01-01

    I denne artikel introduceres Design Based Research for første gang på dansk i et videnskabeligt tidsskrift. Artiklen præsenterer de grundlæggende antagelser, som ligger til grund for Design Based Research-traditionen, og artiklen diskuterer de principper, som ligger til grund for gennemførelse af...... et DBR-forskningsprojekt. Med udgangspunkt i forsknings- og udviklingsprojektet ELYK: E-læring, Yderområder og Klyngedannelse, præsenteres den innovationsmodel, som projektet har udviklet med udgangspunkt i Design Based Research traditionen. ELYKs DBR innovationsmodel har vist sig effektiv i forhold...... til projektfremdrift, brugerinvolvering og vidensgenerering, og den vil kunne inspirere andre med interesse i forskningsbaseret udvikling af didaktisk design, der er medieret af digitale teknologier....

  2. Problem Based Learning

    DEFF Research Database (Denmark)

    de Graaff, Erik; Guerra, Aida

    , the key principles remain the same everywhere. Graaff & Kolmos (2003) identify the main PBL principles as follows: 1. Problem orientation 2. Project organization through teams or group work 3. Participant-directed 4. Experiental learning 5. Activity-based learning 6. Interdisciplinary learning and 7......Problem-Based Learning (PBL) is an innovative method to organize the learning process in such a way that the students actively engage in finding answers by themselves. During the past 40 years PBL has evolved and diversified resulting in a multitude in variations in models and practices. However...... in Engineering Education. In answer to the requests for visits the Aalborg Centre for Problem Based Learning in Engineering Science and Sustainability under the auspices of UNESCO (UCPBL) a two days programme for visitors is offered two times a year. The workshop is an introduction workshop to the Aalborg PBL...

  3. Compression-based Similarity

    CERN Document Server

    Vitanyi, Paul M B

    2011-01-01

    First we consider pair-wise distances for literal objects consisting of finite binary files. These files are taken to contain all of their meaning, like genomes or books. The distances are based on compression of the objects concerned, normalized, and can be viewed as similarity distances. Second, we consider pair-wise distances between names of objects, like "red" or "christianity." In this case the distances are based on searches of the Internet. Such a search can be performed by any search engine that returns aggregate page counts. We can extract a code length from the numbers returned, use the same formula as before, and derive a similarity or relative semantics between names for objects. The theory is based on Kolmogorov complexity. We test both similarities extensively experimentally.

  4. Cantilever Based Mass Sensing

    DEFF Research Database (Denmark)

    Dohn, Søren

    2007-01-01

    Cantilever based mass sensors utilize that a change in vibrating mass will cause a change in the resonant frequency. This can be used for very accurate sensing of adsorption and desorption processes on the cantilever surface. The change in resonant frequency caused by a single molecule depends...... on various parameters including the vibrating mass of the cantilever and the frequency at which it vibrates. The minimum amount of molecules detectable is highly dependent on the noise of the system as well as the method of readout. The aim of this Ph.D. thesis has been twofold: To develop a readout method...... suitable for a portable device and to investigate the possibility of enhancing the functionality and sensitivity of cantilever based mass sensors. A readout method based on the hard contact between the cantilever and a biased electrode placed in close proximity to the cantilever is proposed. The viability...

  5. Evidence-Based Development

    DEFF Research Database (Denmark)

    Hertzum, Morten; Simonsen, Jesper

    2004-01-01

    Systems development is replete with projects that represent substantial resource investments but result in systems that fail to meet users’ needs. Evidence-based development is an emerging idea intended to provide means for managing customer-vendor relationships and working systematically toward...... meeting customer needs. We are suggesting that the effects of the use of a system should play a prominent role in the contractual definition of IT projects and that contract fulfilment should be determined on the basis of evidence of these effects. Based on two ongoing studies of home-care management...

  6. Inkjet-based micromanufacturing

    CERN Document Server

    Korvink, Jan G; Shin, Dong-Youn; Brand, Oliver; Fedder, Gary K; Hierold, Christofer; Tabata, Osamu

    2012-01-01

    Inkjet-based Micromanufacturing Inkjet technology goes way beyond putting ink on paper: it enables simpler, faster and more reliable manufacturing processes in the fields of micro- and nanotechnology. Modern inkjet heads are per se precision instruments that deposit droplets of fluids on a variety of surfaces in programmable, repeating patterns, allowing, after suitable modifications and adaptations, the manufacturing of devices such as thin-film transistors, polymer-based displays and photovoltaic elements. Moreover, inkjet technology facilitates the large-scale production of flexible RFID tr

  7. Animation-based Sketching

    DEFF Research Database (Denmark)

    Vistisen, Peter

    This thesis is based on the results of a three-year long PhD-study at the Department of Communication and Psychology at Aalborg University. The thesis consist of five original papers, a book manuscript, as well as a linking text with the thesis’ research questions, research design, and summary...... experiments has been carried out, applying animation-based sketching in various contexts and at varying points in the design process. In the studies, I evaluate the viability of the approach, the practical integration into the design process, and map how consensus between stakeholders in design can...

  8. Identity-based encryption

    CERN Document Server

    Chatterjee, Sanjit

    2011-01-01

    Identity Based Encryption (IBE) is a type of public key encryption and has been intensely researched in the past decade. Identity-Based Encryption summarizes the available research for IBE and the main ideas that would enable users to pursue further work in this area. This book will also cover a brief background on Elliptic Curves and Pairings, security against chosen Cipher text Attacks, standards and more. Advanced-level students in computer science and mathematics who specialize in cryptology, and the general community of researchers in the area of cryptology and data security will find Ide

  9. Video-based rendering

    CERN Document Server

    Magnor, Marcus A

    2005-01-01

    Driven by consumer-market applications that enjoy steadily increasing economic importance, graphics hardware and rendering algorithms are a central focus of computer graphics research. Video-based rendering is an approach that aims to overcome the current bottleneck in the time-consuming modeling process and has applications in areas such as computer games, special effects, and interactive TV. This book offers an in-depth introduction to video-based rendering, a rapidly developing new interdisciplinary topic employing techniques from computer graphics, computer vision, and telecommunication en

  10. Software Design Document Vehicle Simulation CSCI (5). Volume 4, Appendices

    Science.gov (United States)

    1991-06-01

    findlocation in libimage.c, (null) kinematicscalcvelocity in calc-v.c, (null) kinematics-update-p in update-p.c, (null) E-55 BBN Systems and TechnoIlogies ...cig-stop in Ocig-stop.c, (null) E-255 BBN Systems and Technoilogies Vehicles CSCI cig-preparejic’.op in cig-no-op.c, (null) cig-reconfig-s=a in cig-j...network-set-commo-kill(kill-status) FUNCTION: network-set- mobility kill(kill-status) FUNCTION: network-set-firepower-kill(kilLstatus) FILE: dust

  11. Highly reflective rear surface passivation design for ultra-thin Cu(In,Ga) Se-2 solar cells

    OpenAIRE

    Vermang, Bart; Timo Watjen, Jorn; Fjallstrom, Viktor; Rostvall, Fredrik; Edoff, Marika; Gunnarsson, Rickard; Pilch, Iris; Helmersson, Ulf; Kotipalli, Ratan; Henry, Frederic; Flandre, Denis

    2015-01-01

    Al2O3 rear surface passivated ultra-thin Cu(In,Ga)Se-2 (CIGS) solar cells with Mo nano-particles (NPs) as local rear contacts are developed to demonstrate their potential to improve optical confinement in ultra-thin CIGS solar cells. The CIGS absorber layer is 380 nm thick and the Mo NPs are deposited uniformly by an up-scalable technique and have typical diameters of 150 to 200 nm. The Al2O3 layer passivates the CIGS rear surface between the Mo NPs, while the rear CIGS interface in contact w...

  12. Surfel Based Geometry Resonstruction

    DEFF Research Database (Denmark)

    Andersen, Vedrana; Aanæs, Henrik; Bærentzen, Jakob Andreas

    2010-01-01

    We propose a method for retrieving a piecewise smooth surface from noisy data. In data acquired by a scanning process sampled points are almost never on the discontinuities making reconstruction of surfaces with sharp features difficult. Our method is based on a Markov Random Field (MRF) formulat...

  13. Cotton-based nonwovens

    Science.gov (United States)

    This article is an abbreviated description of a new cotton-based nonwovens research program at the Southern Regional Research Center, which is one of the four regional research centers of the Agricultural Research Service, U.S. Department of Agriculture. Since cotton is a significant cash crop inte...

  14. Protein Crystal Based Nanomaterials

    Science.gov (United States)

    Bell, Jeffrey A.; VanRoey, Patrick

    2001-01-01

    This is the final report on a NASA Grant. It concerns a description of work done, which includes: (1) Protein crystals cross-linked to form fibers; (2) Engineering of protein to favor crystallization; (3) Better knowledge-based potentials for protein-protein contacts; (4) Simulation of protein crystallization.

  15. Evidence based practice

    DEFF Research Database (Denmark)

    Hjørland, Birger

    2011-01-01

    making that is established in research as well as an optimization of every link in documentation and search processes. EBP is based on the philosophical doctrine of empiricism and, therefore, it is subject to the criticism that has been raised against empiricism. The main criticism of EBP...

  16. XML Based UIScript

    Institute of Scientific and Technical Information of China (English)

    CAI Bin; LIAO Jian-xin; SHEN Qi-wei

    2004-01-01

    In this paper, after the analyzing the UIScript mechanism in intelligent peripheral, a new approach of XML-based UIScript is put forward. The related issues such as the design of UIScript language, the execution environment and its relationship with other script languages are discussed.

  17. Evidence-based guidelines

    DEFF Research Database (Denmark)

    Rovira, Àlex; Wattjes, Mike P; Tintoré, Mar

    2015-01-01

    diagnosis in patients with MS. The aim of this article is to provide guidelines for the implementation of MRI of the brain and spinal cord in the diagnosis of patients who are suspected of having MS. These guidelines are based on an extensive review of the recent literature, as well as on the personal...

  18. Acid-Base Homeostasis.

    Science.gov (United States)

    Hamm, L Lee; Nakhoul, Nazih; Hering-Smith, Kathleen S

    2015-12-07

    Acid-base homeostasis and pH regulation are critical for both normal physiology and cell metabolism and function. The importance of this regulation is evidenced by a variety of physiologic derangements that occur when plasma pH is either high or low. The kidneys have the predominant role in regulating the systemic bicarbonate concentration and hence, the metabolic component of acid-base balance. This function of the kidneys has two components: reabsorption of virtually all of the filtered HCO3(-) and production of new bicarbonate to replace that consumed by normal or pathologic acids. This production or generation of new HCO3(-) is done by net acid excretion. Under normal conditions, approximately one-third to one-half of net acid excretion by the kidneys is in the form of titratable acid. The other one-half to two-thirds is the excretion of ammonium. The capacity to excrete ammonium under conditions of acid loads is quantitatively much greater than the capacity to increase titratable acid. Multiple, often redundant pathways and processes exist to regulate these renal functions. Derangements in acid-base homeostasis, however, are common in clinical medicine and can often be related to the systems involved in acid-base transport in the kidneys.

  19. BASE - Progress Report 2015

    CERN Document Server

    Ulmer, S; Mooser, A; Sellner, S; Nagahama, H; Higuchi, T; Borchert, M; Schneider, G; Tanaka, T; Blaum, K; Matsuda, Y; Ospelkaus, C; Quint, W; Walz, J; Yamazaki, Y; CERN. Geneva. SPS and PS Experiments Committee; SPSC

    2016-01-01

    The BASE collaboration aims at high-precision comparisons of the fundamental properties of the proton and the antiproton, namely, the magnetic g-factors as well as the charge-to-mass ratios of the particles. This annual report summarizes the achievements made in CERN's 2015 antiproton run.

  20. Web Based VRML Modelling

    NARCIS (Netherlands)

    Kiss, S.

    2001-01-01

    Presents a method to connect VRML (Virtual Reality Modeling Language) and Java components in a Web page using EAI (External Authoring Interface), which makes it possible to interactively generate and edit VRML meshes. The meshes used are based on regular grids, to provide an interaction and modeling

  1. REST based service composition

    DEFF Research Database (Denmark)

    Grönvall, Erik; Ingstrup, Mads; Pløger, Morten

    2011-01-01

    This paper presents an ongoing work developing and testing a Service Composition framework based upon the REST architecture named SECREST. A minimalistic approach have been favored instead of a creating a complete infrastructure. One focus has been on the system's interaction model. Indeed, an aim...

  2. School Based Health Centers

    Science.gov (United States)

    Children's Aid Society, 2012

    2012-01-01

    School Based Health Centers (SBHC) are considered by experts as one of the most effective and efficient ways to provide preventive health care to children. Few programs are as successful in delivering health care to children at no cost to the patient, and where they are: in school. For many underserved children, The Children's Aid Society's…

  3. Speckle-based wavemeter

    DEFF Research Database (Denmark)

    Hanson, Steen Grüner; Jakobsen, Michael Linde; Chakrabarti, Maumita

    2015-01-01

    A spectrometer based on the application of dynamic speckles will be disclosed. The method relies on scattering of primarily coherent radiation from a slanted rough surface. The scattered radiation is collected on a detector array and the speckle displacement is monitored during a change in the in...

  4. Nanocarbon-based photovoltaics.

    Science.gov (United States)

    Bernardi, Marco; Lohrman, Jessica; Kumar, Priyank V; Kirkeminde, Alec; Ferralis, Nicola; Grossman, Jeffrey C; Ren, Shenqiang

    2012-10-23

    Carbon materials are excellent candidates for photovoltaic solar cells: they are Earth-abundant, possess high optical absorption, and maintain superior thermal and photostability. Here we report on solar cells with active layers made solely of carbon nanomaterials that present the same advantages of conjugated polymer-based solar cells, namely, solution processable, potentially flexible, and chemically tunable, but with increased photostability and the possibility to revert photodegradation. The device active layer composition is optimized using ab initio density functional theory calculations to predict type-II band alignment and Schottky barrier formation. The best device fabricated is composed of PC(70)BM fullerene, semiconducting single-walled carbon nanotubes, and reduced graphene oxide. This active-layer composition achieves a power conversion efficiency of 1.3%-a record for solar cells based on carbon as the active material-and we calculate efficiency limits of up to 13% for the devices fabricated in this work, comparable to those predicted for polymer solar cells employing PCBM as the acceptor. There is great promise for improving carbon-based solar cells considering the novelty of this type of device, the high photostability, and the availability of a large number of carbon materials with yet untapped potential for photovoltaics. Our results indicate a new strategy for efficient carbon-based, solution-processable, thin film, photostable solar cells.

  5. Internet based benchmarking

    DEFF Research Database (Denmark)

    Bogetoft, Peter; Nielsen, Kurt

    2005-01-01

    We discuss the design of interactive, internet based benchmarking using parametric (statistical) as well as nonparametric (DEA) models. The user receives benchmarks and improvement potentials. The user is also given the possibility to search different efficiency frontiers and hereby to explore al...... alternative improvement strategies. Implementations of both a parametric and a non-parametric model are presented....

  6. Diffusion Based Photon Mapping

    DEFF Research Database (Denmark)

    Schjøth, Lars; Sporring, Jon; Fogh Olsen, Ole

    2008-01-01

    . To address this problem, we introduce a photon mapping algorithm based on nonlinear anisotropic diffusion. Our algorithm adapts according to the structure of the photon map such that smoothing occurs along edges and structures and not across. In this way, we preserve important illumination features, while...

  7. Performance based fault diagnosis

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik

    2002-01-01

    Different aspects of fault detection and fault isolation in closed-loop systems are considered. It is shown that using the standard setup known from feedback control, it is possible to formulate fault diagnosis problems based on a performance index in this general standard setup. It is also shown...

  8. Model-based consensus

    NARCIS (Netherlands)

    Boumans, Marcel

    2014-01-01

    The aim of the rational-consensus method is to produce “rational consensus”, that is, “mathematical aggregation”, by weighing the performance of each expert on the basis of his or her knowledge and ability to judge relevant uncertainties. The measurement of the performance of the experts is based on

  9. Model-based consensus

    NARCIS (Netherlands)

    M. Boumans

    2014-01-01

    The aim of the rational-consensus method is to produce "rational consensus", that is, "mathematical aggregation", by weighing the performance of each expert on the basis of his or her knowledge and ability to judge relevant uncertainties. The measurement of the performance of the experts is based on

  10. Orff-Based Improvisation.

    Science.gov (United States)

    Thomas, Judith

    1980-01-01

    Described are improvisational activities based on the Orff-Schulwerk teaching technique which include: sound and movement; sound and movement plus visuals; interpretation of designs from nature, architecture, paintings, rotating rondo, singing hands, and moving from words to song. Pictures of children participating in these activities are…

  11. Aptamer-based nanobiosensors.

    Science.gov (United States)

    Kim, Yeon Seok; Raston, Nurul Hanun Ahmad; Gu, Man Bock

    2016-02-15

    It has been more than two decades since aptamer and the systematic evolution of ligands by exponential enrichment (SELEX) method were discovered by Larry Gold and Andrew Ellington in 1990, respectively. Based on the various advantages of aptamers, they have become a potent rival of antibodies in therapeutics and bio-analysis. Especially, the recent advances in aptamer biosensor application are remarkable due to its intrinsic properties of aptamers as nucleic acids and target induced conformational changes, in addition to the introduction of graphene oxide-based easy and simple immobilization-free screening method even for dual aptamers. In addition, the incorporation of various nanomaterials such as metallic nanoparticles, carbon materials, and functional nanospheres in aptasensors has facilitated the improvement of analytical performance and commercial application of aptasensors. In this review, recent prominent reports on aptasensors utilizing nanomaterials were introduced to understand the principle of aptamer-based biosensors and provide an insight for new strategies of aptasensors and the application of various nanomaterials. The perspective on aptamer-based biosensors and diagnostics was also discussed in view of technology and market.

  12. Non-Toxic Buffer Layers in Flexible Cu(In,GaSe2 Photovoltaic Cell Applications with Optimized Absorber Thickness

    Directory of Open Access Journals (Sweden)

    Md. Asaduzzaman

    2017-01-01

    Full Text Available Absorber layer thickness gradient in Cu(In1−xGaxSe2 (CIGS based solar cells and several substitutes for typical cadmium sulfide (CdS buffer layers, such as ZnS, ZnO, ZnS(O,OH, Zn1−xSnxOy (ZTO, ZnSe, and In2S3, have been analyzed by a device emulation program and tool (ADEPT 2.1 to determine optimum efficiency. As a reference type, the CIGS cell with CdS buffer provides a theoretical efficiency of 23.23% when the optimum absorber layer thickness was determined as 1.6 μm. It is also observed that this highly efficient CIGS cell would have an absorber layer thickness between 1 μm and 2 μm whereas the optimum buffer layer thickness would be within the range of 0.04–0.06 μm. Among all the cells with various buffer layers, the best energy conversion efficiency of 24.62% has been achieved for the ZnO buffer layer based cell. The simulation results with ZnS and ZnO based buffer layer materials instead of using CdS indicate that the cell performance would be better than that of the CdS buffer layer based cell. Although the cells with ZnS(O,OH, ZTO, ZnSe, and In2S3 buffer layers provide slightly lower efficiencies than that of the CdS buffer based cell, the use of these materials would not be deleterious for the environment because of their non-carcinogenic and non-toxic nature.

  13. Thin Film Photovoltaic Cells on Flexible Substrates Integrated with Energy Storage

    Science.gov (United States)

    2011-11-30

    Synthesis of CZTS thin films using TBDS as a sulfur source Thin film solar cells based on Cu(In,Ga)(S,Se)2 and CdTe have demonstrated significant...efficient ones at the laboratory level and have demonstrated efficincies in the range of-20% [3]. However, both CIGS and CdTe based thin film solar...11/2011 2. REPORT TYPE Quarterly 3. DATES COVERED (From - To) 01/09/2011 to 30/11/2011 4. TITLE AND SUBTITLE Thin Film Photovoltaic Cells on

  14. Advances in thin-film solar cells

    CERN Document Server

    Dharmadasa, I M

    2012-01-01

    This book concentrates on the latest developments in our understanding of solid-state device physics. The material presented is mainly experimental and based on CdTe thin-film solar cells. It extends these new findings to CIGS thin-film solar cells and presents a new device design based on graded bandgap multilayer solar cells. This design has been experimentally tested using the well-researched GaAs/AlGaAs system and initial devices have shown impressive device parameters. These devices are capable of absorbing all radiation (UV, visible, and infra-red) within the solar spectrum and combines

  15. Effect of post deposition annealing on the structure, morphology, optical and electrical properties of CuInGaSe2 thin films

    Science.gov (United States)

    Pugalenthi, A. S.; Balasundaraprabhu, R.; Prasanna, S.; Habibuddin, S.; Muthukumarasamy, N.; Mohan Rao, G.; Kannan, M. D.

    2016-12-01

    Polycrystalline copper indium gallium diselenide (CIGS) thin film is a favourable candidate for solar cell applications. In the present work the effect of post-deposition annealing on the structure, surface morphology, optical and electrical properties are discussed. Initially, gallium rich CIG thin films were deposited by RF magnetron sputtering followed by an indium rich CIG layer and subjected to selenization to realize CIGS stoichiometry. X-ray diffraction (XRD) results revealed the polycrystalline nature of the films with chalcopyrite structure having preferential orientation along direction normal to the substrate. Optical properties of CIGS thin films were studied using UV-vis spectrophotometry and the band gap of CIGS was found to be around 1.15 eV. Hall Effect studies carried out on the CIGS thin films showed a linear dependence of conductivity with post deposition annealing. The elemental composition of the films was quantified using X-ray photoelectron spectroscopy (XPS) and the results are discussed.

  16. Fabrication of the CuInGaSe Pellet and Characterization of the Thin Film

    Science.gov (United States)

    Jeon, Hunsoo; Lee, Ahreum; Lee, Gang-Seok; Jo, Dong-Wan; Ok, Jin-Eun; Kim, Kyoung Hwa; Yang, Min; Yi, Sam Nyung; Ahn, Hyung Soo; Cho, Chae-Ryong; Kim, Suck-Whan; Ha, Hong-Ju

    2011-01-01

    CuInGaSe (CIGS) mixed-source was prepared by hydride vapor transport method (HVT). The new source synthesis method was attempted by mixing several metals such as Cu, In, Ga, and Se with 3:5:1:4 mass ratios. This mixed-source was soaked at 1090 °C for 90 min in nitrogen atmosphere. Then, the CIGS was grinded up and formed the state of powder and the CIGS pellet was made by pressure machine. The diameter of pellet is 10 mm. The CIGS thin film was deposited on soda lime glass with evaporated molybdenum layer by e-beam evaporating this CIGS pellet. For crystallization of CIGS thin film, we measured scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). High intensity X-ray peaks diffracted from (112), (204)/(220), (116)/(312), and (400) of CIGS thin film and from (110) of Mo were confirmed by XRD measurement.

  17. Sparse approximation with bases

    CERN Document Server

    2015-01-01

    This book systematically presents recent fundamental results on greedy approximation with respect to bases. Motivated by numerous applications, the last decade has seen great successes in studying nonlinear sparse approximation. Recent findings have established that greedy-type algorithms are suitable methods of nonlinear approximation in both sparse approximation with respect to bases and sparse approximation with respect to redundant systems. These insights, combined with some previous fundamental results, form the basis for constructing the theory of greedy approximation. Taking into account the theoretical and practical demand for this kind of theory, the book systematically elaborates a theoretical framework for greedy approximation and its applications.  The book addresses the needs of researchers working in numerical mathematics, harmonic analysis, and functional analysis. It quickly takes the reader from classical results to the latest frontier, but is written at the level of a graduate course and do...

  18. Location-based Scheduling

    DEFF Research Database (Denmark)

    Andersson, Niclas; Christensen, Knud

    the predominant scheduling method since it was introduced in the late 1950s. Over the years, CPM has proven to be a very powerful technique for planning, scheduling and controlling projects, which among other things is indicated by the development of a large number of CPM-based software applications available...... to the identified limitations of the CPM method, an alternative planning and scheduling methodology that includes locations is tested. Location-based Scheduling (LBS) implies a shift in focus, from primarily the activities to the flow of work through the various locations of the project, i.e. the building. LBS uses...... the graphical presentation technique of Line-of-balance, which is adapted for planning and management of work-flows that facilitates resources to perform their work without interruptions caused by other resources working with other activities in the same location. As such, LBS and Lean Construction share...

  19. Flow Based Algorithm

    Directory of Open Access Journals (Sweden)

    T. Karpagam

    2012-01-01

    Full Text Available Problem statement: Network topology design problems find application in several real life scenario. Approach: Most designs in the past either optimize for a single criterion like shortest or cost minimization or maximum flow. Results: This study discussed about solving a multi objective network topology design problem for a realistic traffic model specifically in the pipeline transportation. Here flow based algorithm focusing to transport liquid goods with maximum capacity with shortest distance, this algorithm developed with the sense of basic pert and critical path method. Conclusion/Recommendations: This flow based algorithm helps to give optimal result for transporting maximum capacity with minimum cost. It could be used in the juice factory, milk industry and its best alternate for the vehicle routing problem.

  20. Content Based Video Retrieval

    Directory of Open Access Journals (Sweden)

    B. V. Patel

    2012-10-01

    Full Text Available Content based video retrieval is an approach for facilitating the searching and browsing of large image collections over World Wide Web. In this approach, video analysis is conducted on low level visual properties extracted from video frame. We believed that in order to create an effective video retrieval system, visual perception must be taken into account. We conjectured that a technique which employs multiple features for indexing and retrieval would be more effective in the discrimination and search tasks of videos. In order to validate this claim, content based indexing and retrieval systems were implemented using color histogram, various texture features and other approaches. Videos were stored in Oracle 9i Database and a user study measured correctness of response.

  1. Knowledge based maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Sturm, A. [Hamburgische Electacitaets-Werke AG Hamburg (Germany)

    1997-12-31

    The establishment of maintenance strategies is of crucial significance for the reliability of a plant and the economic efficiency of maintenance measures. Knowledge about the condition of components and plants from the technical and business management point of view therefore becomes one of the fundamental questions and the key to efficient management and maintenance. A new way to determine the maintenance strategy can be called: Knowledge Based Maintenance. A simple method for determining strategies while taking the technical condition of the components of the production process into account to the greatest possible degree which can be shown. A software with an algorithm for Knowledge Based Maintenance leads the user during complex work to the determination of maintenance strategies for this complex plant components. (orig.)

  2. Spintronics-based computing

    CERN Document Server

    Prenat, Guillaume

    2015-01-01

    This book provides a comprehensive introduction to spintronics-based computing for the next generation of ultra-low power/highly reliable logic, which is widely considered a promising candidate to replace conventional, pure CMOS-based logic. It will cover aspects from device to system-level, including magnetic memory cells, device modeling, hybrid circuit structure, design methodology, CAD tools, and technological integration methods. This book is accessible to a variety of readers and little or no background in magnetism and spin electronics are required to understand its content.  The multidisciplinary team of expert authors from circuits, devices, computer architecture, CAD and system design reveal to readers the potential of spintronics nanodevices to reduce power consumption, improve reliability and enable new functionality.  .

  3. Evidence-based policy

    DEFF Research Database (Denmark)

    Vohnsen, Nina Holm

    2013-01-01

    A current ambition in welfare states as diverse as Denmark, the UK, and in the USA is to base political decision making on rigorous research (Cartwright et al 2009; Mulgan 2009; Bason 2010). Sound as this might seem the ambition has nevertheless been problematized by both policy-makers and the re......A current ambition in welfare states as diverse as Denmark, the UK, and in the USA is to base political decision making on rigorous research (Cartwright et al 2009; Mulgan 2009; Bason 2010). Sound as this might seem the ambition has nevertheless been problematized by both policy...... a full account, see Vohnsen 2011). These insights will be relevant for the anthropological researcher of legislative processes who wishes to move beyond a merely discursive approach to the study of policy and politics....

  4. Situation based housing

    DEFF Research Database (Denmark)

    Duelund Mortensen, Peder; Welling, Helen; Wiell Nordberg, Lene

    2007-01-01

    of approaches to these goals. This working paper reviews not only a selection of new housing types, but also dwellings from the past, which each contain an aspect of changeability. Our study is based on information from users in the selected housing schemes, gathered from questionnaires, information about...... personal furnishing and zoning as well as interviews. The study is also based on analyses of the architectural configurations of space, light and materiality. Our main question is: can the goal of architectural quality be maintained together with greater possibilities for individual development...... research results will be employed to create a categorization of housing suitable for changing life conditions and with a strong emphasis on high architectural quality...

  5. Lignocellulose-based bioproducts

    CERN Document Server

    Karimi, Keikhosro

    2015-01-01

    This volume provides the technical information required for the production of biofuels and chemicals from lignocellulosic biomass. It starts with a brief overview of the importance, applications, and production processes of different lignocellulosic products. Further chapters review the perspectives of waste-based biofuels and biochemicals; the pretreatment of lignocellulosic biomass for biofuel production; cellulolytic enzyme systems for the hydrolysis of lignocelluloses; and basic and applied aspects of the production of bioethanol, biogas, biohydrogen, and biobutanol from lignocelluloses.

  6. Vehicle Based Vector Sensor

    Science.gov (United States)

    2015-09-28

    300001 1 of 16 VEHICLE-BASED VECTOR SENSOR STATEMENT OF GOVERNMENT INTEREST [0001] The invention described herein may be manufactured and...unmanned underwater vehicle that can function as an acoustic vector sensor . (2) Description of the Prior Art [0004] It is known that a propagating...mechanics. An acoustic vector sensor measures the particle motion via an accelerometer and combines Attorney Docket No. 300001 2 of 16 the

  7. Alphavirus-Based Vaccines

    OpenAIRE

    Kenneth Lundstrom

    2014-01-01

    Alphavirus vectors have demonstrated high levels of transient heterologous gene expression both in vitro and in vivo and, therefore, possess attractive features for vaccine development. The most commonly used delivery vectors are based on three single-stranded encapsulated alphaviruses, namely Semliki Forest virus, Sindbis virus and Venezuelan equine encephalitis virus. Alphavirus vectors have been applied as replication-deficient recombinant viral particles and, more recently, as replication...

  8. Luxury-based Growth

    OpenAIRE

    Shiro Kuwahara

    2006-01-01

    Assuming that there exists a preference for luxury goods and a knowledge spillover from luxury goods production to goods production, this paper constructs an endogenous economic growth model. The model predicts two steady states: one is a steady positive growth state with regard to luxury goods production, and the other is a zero growth state in the absence of luxury goods production. Thus, this study examines the polarization of economies based on luxury goods consumption

  9. Dictionary Based Image Segmentation

    DEFF Research Database (Denmark)

    Dahl, Anders Bjorholm; Dahl, Vedrana Andersen

    2015-01-01

    We propose a method for weakly supervised segmentation of natural images, which may contain both textured or non-textured regions. Our texture representation is based on a dictionary of image patches. To divide an image into separated regions with similar texture we use an implicit level sets...... in an efficient implementation of our segmentation method. We experimentally validated our approach on a number of natural as well as composed images....

  10. Arduino based laser control

    OpenAIRE

    Bernal Muñoz, Ferran

    2015-01-01

    ARDUINO is a vey usefull platform for prototypes. In this project ARDUINO will be used for controling a Semiconductor Tuneable Laser. [ANGLÈS] Diode laser for communications control based on an Arduino board. Temperature control implementation. Software and hardware protection for the laser implementation. [CASTELLÀ] Control de un láser de comunicaciones ópticas desde el ordenador utilizando una placa Arduino. Implementación de un control de temperatura y protección software y hardware ...

  11. Plasmonics based VLSI processes

    Directory of Open Access Journals (Sweden)

    Shreya Bhattacharya

    2013-04-01

    Full Text Available In continuum to my previous paper titled‘Implementation of plasmonics in VLSI’, this paperattempts to explore further, the actual physicalrealization of an all-plasmonic chip. In this paper,various methods of plasmon-basedphotolithography have been discussed and anobservation is made w.r.t the cost effectiveness andease of adaptability. Also, plasmonics based activeelement has been discussed which would helpunravel further arenas ofapproaches and methodstowards the realization of an all-plasmonic chip.

  12. Operational Based Vision Assessment

    Science.gov (United States)

    2014-02-01

    Garvin Lt Col Robert Forino Dr. Jeff Hovis Dr. Frank Kooi Lt Col Jay Flottmann Mr. William Sweet Ms. Sandra Miarecki Mr. Allen Bowersox...System Program Office (now the Air Force Life Cycle Management Center, Agile Combat Support Directorate) at Wright-Patterson Air Force Base, OH. In...mechanical shutters. Additionally, the quality of the LCD shutter degrades over time and may cause shifts in color appearance. Because of these issues

  13. Projectile Base Flow Analysis

    Science.gov (United States)

    2007-11-02

    S) AND ADDRESS(ES) DCW Industries, Inc. 5354 Palm Drive La Canada, CA 91011 8. PERFORMING ORGANIZATION...REPORT NUMBER DCW -38-R-05 9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) U. S. Army Research Office...Turbulence Modeling for CFD, Second Edition, DCW Industries, Inc., La Cañada, CA. Wilcox, D. C. (2001), “Projectile Base Flow Analysis,” DCW

  14. Graphene-based biosensors

    Science.gov (United States)

    Lebedev, A. A.; Davydov, V. Yu.; Novikov, S. N.; Litvin, D. P.; Makarov, Yu. N.; Klimovich, V. B.; Samoilovich, M. P.

    2016-07-01

    Results of developing and testing graphene-based sensors capable of detecting protein molecules are presented. The biosensor operation was checked using an immunochemical system comprising fluorescein dye and monoclonal antifluorescein antibodies. The sensor detects fluorescein concentration on a level of 1-10 ng/mL and bovine serum albumin-fluorescein conjugate on a level of 1-5 ng/mL. The proposed device has good prospects for use for early diagnostics of various diseases.

  15. Sea Basing Logistiek

    Science.gov (United States)

    2007-11-01

    iets wat nu voor zware goederen niet mogeljk is met de middelen binnen de Nederlandse krijgsmachit. Nederland heeft bijvoorbeeld (nog) geen specifieke...weer gevechtsklaar zijn. Nederlandse troepen voeren de reconstitute fase in het algemeen uit in Nederland . [Kang&Gue] A special concern in sea based...besluit Nederland zelf in te grijpen. De Nederlandse vredesmissie bevindt zich nabij de kust. maar ver van de grens met buurlanden. De operatie kan niet

  16. Microbead agglutination based assays

    KAUST Repository

    Kodzius, Rimantas

    2013-01-21

    We report a simple and rapid room temperature assay for point-of-care (POC) testing that is based on specific agglutination. Agglutination tests are based on aggregation of microbeads in the presence of a specific analyte thus enabling the macroscopic observation. Such tests are most often used to explore antibody-antigen reactions. Agglutination has been used for protein assays using a biotin/streptavidin system as well as a hybridization based assay. The agglutination systems are prone to selftermination of the linking analyte, prone to active site saturation and loss of agglomeration at high analyte concentrations. We investigated the molecular target/ligand interaction, explaining the common agglutination problems related to analyte self-termination, linkage of the analyte to the same bead instead of different microbeads. We classified the agglutination process into three kinds of assays: a two- component assay, a three-component assay and a stepped three- component assay. Although we compared these three kinds of assays for recognizing DNA and protein molecules, the assay can be used for virtually any molecule, including ions and metabolites. In total, the optimized assay permits detecting analytes with high sensitivity in a short time, 5 min, at room temperature. Such a system is appropriate for POC testing.

  17. Molecule-based magnets

    Indian Academy of Sciences (India)

    J V Yakhmi

    2009-06-01

    The conventional magnetic materials used in current technology, such as, Fe, Fe2O3, Cr2O3, SmCo5, Nd2Fe14B etc are all atom-based, and their preparation/processing require high temperature routes. Employing self-assembly methods, it is possible to engineer a bulk molecular material with long-range magnetic order, mainly because one can play with the weak intermolecular interactions. Since the first successful synthesis of molecular magnets in 1986, a large variety of them have been synthesized, which can be categorized on the basis of the chemical nature of the magnetic units involved: organic-, metal-based systems, heterobimetallic assemblies, or mixed organic–inorganic systems. The design of molecule-based magnets has also been extended to the design of poly-functional molecular magnets, such as those exhibiting second-order optical nonlinearity, liquid crystallinity, or chirality simultaneously with long-range magnetic order. Solubility, low density and biocompatibility are attractive features of molecular magnets. Being weakly coloured, unlike their opaque classical magnet ‘cousins’ listed above, possibilities of photomagnetic switching exist. Persistent efforts also continue to design the ever-elusive polymer magnets towards applications in industry. While providing a brief overview of the field of molecular magnetism, this article highlights some recent developments in it, with emphasis on a few studies from the author’s own lab.

  18. As bases do petismo

    Directory of Open Access Journals (Sweden)

    David Samuels

    2004-10-01

    Full Text Available A partir dos dados do ESEB de 2002 o autor realiza um estudo das bases eleitorais do PT e de hipóteses sobre a natureza do petismo. Através de técnicas estatísticas multivariadas, são testadas relações do petismo com variáveis demográficas, socioeconômicas e variáveis relativas a questões políticas específicas. Os resultados apontam que apenas a escolaridade tem uma associação específica com o petismo, com implicações para o seu comportamento sócio-político.Based on the results of the 2002 Brazilian Electoral Study, the author analyses the electoral bases of the Worker´s Party and the factors associated with the "petismo". The relationships between the "petismo"and the socioeconomic, demographic and political variables are tested using multivariate analysis. The results indicate that the only "social category"associated with "petismo"is level of education, and it has clear implications to their social and political behavior.

  19. Lunar base initiative 1992

    Science.gov (United States)

    Koelle, H. H.

    The return to the Moon is no longer a question of yes or no, but a question of when and how. The first landing of a human being on the lunar surface in 1969 was a purely national effort of the U.S.A. Building a lunar base and operating it in the next century is rather a task for all nations of this planet, even if one nation could do it alone. However, there are several alternatives to carry out such a program and these will and should be debated during the next years on an urgent basis. To do this, one has to take into account not only the historical accomplishments and the present trends of cooperation in space programs, but also recent geopolitical developments as well as the frame of reference established by international law. The case for an International Lunar Base (ILB) has been presented to the International Academy of Astronautics on 11 October 1987 by the IAA Ad Hoc Committee "Return-to-the-Moon". This draft of a position paper was subsequently published in Acta Astronautica Vol. 17, No. 5, (pp. 463-489) with the request of public debate particularly by the members of the Academy. Some 80 Academicians responded to this invitation by the President of the Academy and voiced their opinions on the questions and issues raised by this draft of a position paper. This led to a refinement of the arguments and assumptions made and it is now possible to prepare an improved position paper proposing concrete steps which may lead to an ILB. An issue of this proportion must start with a discussion of goals and objectives to be arranged in some kind of a ranked order. It also has to take note of the limitations existing at any time by the availability of suitable space transportation systems. These will determine the acquisition date and rate of growth of a lunar base. The logistics system will also greatly influence the base characteristics and layout. The availability of heavy lift launch vehicles would simplify the task and allow to concentrate the construction

  20. Improving the efficiency of copper indium gallium (Di-)selenide (CIGS) solar cells through integration of a moth-eye textured resist with a refractive index similar to aluminum doped zinc oxide

    NARCIS (Netherlands)

    Burghoorn, M.M.A.; Kniknie, B.J.; Deelen, J. van; Xu, M.; Vroon, Z.A.E.P.; Ee, R.J. van; Belt, R. van de; Buskens, P.J.P.

    2014-01-01

    Textured transparent conductors are widely used in thin-film silicon solar cells. They lower the reflectivity at interfaces between different layers in the cell and/or cause an increase in the path length of photons in the Si absorber layer, which both result in an increase in the number of absorbed

  1. Improving the efficiency of copper indium gallium (Di-)selenide (CIGS) solar cells through integration of a moth-eye textured resist with a refractive index similar to aluminum doped zinc oxide

    OpenAIRE

    M. Burghoorn; B. Kniknie; Deelen, J; Xu., M; Z. Vroon; van Ee, R.; van de Belt, R.; Buskens, P

    2014-01-01

    Textured transparent conductors are widely used in thin-film silicon solar cells. They lower the reflectivity at interfaces between different layers in the cell and/or cause an increase in the path length of photons in the Si absorber layer, which both result in an increase in the number of absorbed photons and, consequently, an increase in short-circuit current density (Jsc) and cell efficiency. Through optical simulations, we recently obtained strong indications that texturing of the transp...

  2. Polyolefin-Based Aerogels

    Science.gov (United States)

    Lee, Je Kyun; Gould, George

    2012-01-01

    An organic polybutadiene (PB) rubberbased aerogel insulation material was developed that will provide superior thermal insulation and inherent radiation protection, exhibiting the flexibility, resiliency, toughness, and durability typical of the parent polymer, yet with the low density and superior insulation properties associated with the aerogels. The rubbery behaviors of the PB rubber-based aerogels are able to overcome the weak and brittle nature of conventional inorganic and organic aerogel insulation materials. Additionally, with higher content of hydrogen in their structure, the PB rubber aerogels will also provide inherently better radiation protection than those of inorganic and carbon aerogels. Since PB rubber aerogels also exhibit good hydrophobicity due to their hydrocarbon molecular structure, they will provide better performance reliability and durability as well as simpler, more economic, and environmentally friendly production over the conventional silica or other inorganic-based aerogels, which require chemical treatment to make them hydrophobic. Inorganic aerogels such as silica aerogels demonstrate many unusual and useful properties. There are several strategies to overcoming the drawbacks associated with the weakness and brittleness of silica aerogels. Development of the flexible fiber-reinforced silica aerogel composite blanket has proven one promising approach, providing a conveniently fielded form factor that is relatively robust toward handling in industrial environments compared to silica aerogel monoliths. However, the flexible silica aerogel composites still have a brittle, dusty character that may be undesirable, or even intolerable, in certain applications. Although the cross-linked organic aerogels such as resorcinol-formaldehyde (RF), polyisocyanurate, and cellulose aerogels show very high impact strength, they are also very brittle with little elongation (i.e., less rubbery). Also, silica and carbon aerogels are less efficient

  3. Polymerization Using Phosphazene Bases

    KAUST Repository

    Zhao, Junpeng

    2015-09-01

    In the recent rise of metal-free polymerization techniques, organic phosphazene superbases have shown their remarkable strength as promoter/catalyst for the anionic polymerization of various types of monomers. Generally, the complexation of phosphazene base with the counterion (proton or lithium cation) significantly improves the nucleophilicity of the initiator/chain end resulting in highly enhanced polymerization rates, as compared with conventional metalbased initiating systems. In this chapter, the general features of phosphazenepromoted/catalyzed polymerizations and the applications in macromolecular engineering (synthesis of functionalized polymers, block copolymers, and macromolecular architectures) are discussed with challenges and perspectives being pointed out.

  4. Alphavirus-Based Vaccines.

    Science.gov (United States)

    Lundstrom, Kenneth

    2016-01-01

    Alphavirus vectors based on Semliki Forest virus, Sindbis virus, and Venezuelan equine encephalitis virus have been widely applied for vaccine development. Naked RNA replicons, recombinant viral particles, and layered DNA vectors have been subjected to immunization in preclinical animal models with antigens for viral targets and tumor antigens. Moreover, a limited number of clinical trials have been conducted in humans. Vaccination with alphavirus vectors has demonstrated efficient immune responses and has showed protection against challenges with lethal doses of virus and tumor cells, respectively. Moreover, vaccines have been developed against alphaviruses causing epidemics such as Chikungunya virus.

  5. Agent-Based Optimization

    CERN Document Server

    Jędrzejowicz, Piotr; Kacprzyk, Janusz

    2013-01-01

    This volume presents a collection of original research works by leading specialists focusing on novel and promising approaches in which the multi-agent system paradigm is used to support, enhance or replace traditional approaches to solving difficult optimization problems. The editors have invited several well-known specialists to present their solutions, tools, and models falling under the common denominator of the agent-based optimization. The book consists of eight chapters covering examples of application of the multi-agent paradigm and respective customized tools to solve  difficult optimization problems arising in different areas such as machine learning, scheduling, transportation and, more generally, distributed and cooperative problem solving.

  6. [Evidence-based physiotherapy].

    Science.gov (United States)

    Bender, Tamás

    2013-12-01

    This article on physiotherapy presents some current evidence stating the strengths and weaknesses of the physiotherapeutic procedures. In the area of physiotherapy empirical data obtained during decades were overtaken by evidence from current studies. The author points out the great problem of physiotherapy, namely the heterogeneity of the applied parameters. Knowledge of current evidence may be very important and helpful for the physicians, but the author proposes, from the practical point of view, that physiotherapeutical procedures based on exprience and used for many years should not be entirely neglected. Nowadays physiotherapy plays an important role in the treament of locomotor diseases but its use is increasing in other fields of medicine, as well.

  7. Sustainability Base Construction Update

    Science.gov (United States)

    Mewhinney, Michael

    2012-01-01

    Construction of the new Sustainability Base Collaborative support facility, expected to become the highest performing building in the federal government continues at NASA's Ames Research Center, Moffet Field, Calif. The new building is designed to achieve a platinum rating under the leadership in Energy and Environment Design (LEED) new construction standards for environmentally sustainable construction developed by the U. S. Green Building Council, Washington, D. C. When completed by the end of 2011, the $20.6 million building will feature near zero net energy consumption, use 90 percent less potable water than conventionally build buildings of equivalent size, and will result in reduced building maintenance costs.

  8. Group Based Interference Alignment

    CERN Document Server

    Ma, Yanjun; Chen, Rui; Yao, Junliang

    2010-01-01

    in $K$-user single-input single-output (SISO) frequency selective fading interference channels, it is shown that the achievable multiplexing gain is almost surely $K/2$ by using interference alignment (IA). However when the signaling dimensions is limited, allocating all the resource to all the users simultaneously is not optimal. According to this problem, a group based interference alignment (GIA) scheme is proposed and a search algorithm is designed to get the group patterns and the resource allocation among them. Analysis results show that our proposed scheme achieves a higher multiplexing gain when the resource is limited.

  9. LIGHTWEIGHT CONCRETE BASED GRANSHLAK

    Directory of Open Access Journals (Sweden)

    NETESA M. I.

    2016-02-01

    Full Text Available Raising of problem. Concrete advisable to obtain a low strength with local secondary resources for recycling and reduce the environmental burden on the environment. But it is important to design such concrete compositions with a reduced flow of cement. It is known that the coefficient of efficiency of use of cement in the concrete of the heavy and B10 is less than about 0.5, which is almost two times smaller than in class B15 concrete and above. Even lower coefficient of efficiency in light concrete cement low strength. Therefore, it is important to find patterns determining the composition of lightweight concrete based on local-products industry with more efficient use of cement in them. Purpose.. Based on the analysis of earlier research results, including with the use of methods of mathematical planning of experiments to determine the concrete contents, which can provide the requirements for the underlying layers of the floor, the compressive strength of which should correspond to the class B5. It is important to provide the required strength at minimum flow of the cement, which is the most expensive and energy-intensive part of concrete. Conclusion. Analysis of the test results of control samples of concrete in 28-day-old, the following laws. The required tensile strength of concrete compressive strength of 7.0 MPa can be obtained in the test range when used in formulations as a filler as the Dnieper hydroelectric power station fly ash and tailings Krivoy Rog iron ore YuGOK. To ensure providing the required characteristic strength of the concrete in the underlying layers of the floor is advisable to use a nominal composition per cubic meter of concrete: cement 160 kg granshlaka Plant named after Petrovsky, 675 kg of fly ash Dnieper HPP 390 kg, 400 kg of sand, 230 liters of water. Thus, while ensuring rational grain composition components can obtain the desired strength lightweight concrete based granshlaka plant Petrovsky, using as fillers

  10. NICKEL-BASE ALLOY

    Science.gov (United States)

    Inouye, H.; Manly, W.D.; Roche, T.K.

    1960-01-19

    A nickel-base alloy was developed which is particularly useful for the containment of molten fluoride salts in reactors. The alloy is resistant to both salt corrosion and oxidation and may be used at temperatures as high as 1800 deg F. Basically, the alloy consists of 15 to 22 wt.% molybdenum, a small amount of carbon, and 6 to 8 wt.% chromium, the balance being nickel. Up to 4 wt.% of tungsten, tantalum, vanadium, or niobium may be added to strengthen the alloy.

  11. Bi-based superconductor

    Directory of Open Access Journals (Sweden)

    S E Mousavi

    2009-08-01

    Full Text Available   In this paper, Bi-Sr-Ca-Cu-O (BCSCCO system superconductor is made by the solid state reaction method. The effect of doping Pb, Cd, Sb, Cu and annealing time on the critical temperature and critical current density have been investigated. The microstructure and morphology of the samples have been studied by X-ray diffraction, scanning electron microscope and energy dispersive X-ray. The results show that the fraction of Bi-2223 phase in the Bi- based superconductor, critical temperature and critical current density depend on the annealing temperature, annealing time and the kind and amount of doping .

  12. Cellular based cancer vaccines

    DEFF Research Database (Denmark)

    Hansen, Morten; Met, O; Svane, I M;

    2012-01-01

    Cancer vaccines designed to re-calibrate the existing host-tumour interaction, tipping the balance from tumor acceptance towards tumor control holds huge potential to complement traditional cancer therapies. In general, limited success has been achieved with vaccines composed of tumor...... in vitro migration via autocrine receptor-mediated endocytosis of CCR7. In the current review, we discuss optimal design of DC maturation focused on pre-clinical as well as clinical results from standard and polarized dendritic cell based cancer vaccines....

  13. Vision-based interaction

    CERN Document Server

    Turk, Matthew

    2013-01-01

    In its early years, the field of computer vision was largely motivated by researchers seeking computational models of biological vision and solutions to practical problems in manufacturing, defense, and medicine. For the past two decades or so, there has been an increasing interest in computer vision as an input modality in the context of human-computer interaction. Such vision-based interaction can endow interactive systems with visual capabilities similar to those important to human-human interaction, in order to perceive non-verbal cues and incorporate this information in applications such

  14. TUNGSTEN BASE ALLOYS

    Science.gov (United States)

    Schell, D.H.; Sheinberg, H.

    1959-12-15

    A high-density quaternary tungsten-base alloy having high mechanical strength and good machinability composed of about 2 wt.% Ni, 3 wt.% Cu, 5 wt.% Pb, and 90wt.% W is described. This alloy can be formed by the powder metallurgy technique of hot pressing in a graphite die without causing a reaction between charge and the die and without formation of a carbide case on the final compact, thereby enabling re-use of the graphite die. The alloy is formable at hot- pressing temperatures of from about 1200 to about 1350 deg C. In addition, there is little component shrinkage, thereby eliminating the necessity of subsequent extensive surface machining.

  15. Unification-Based Glossing

    CERN Document Server

    Hatzivassiloglou, V; Hatzivassiloglou, Vasileios; Knight, Kevin

    1995-01-01

    We present an approach to syntax-based machine translation that combines unification-style interpretation with statistical processing. This approach enables us to translate any Japanese newspaper article into English, with quality far better than a word-for-word translation. Novel ideas include the use of feature structures to encode word lattices and the use of unification to compose and manipulate lattices. Unification also allows us to specify abstract features that delay target-language synthesis until enough source-language information is assembled. Our statistical component enables us to search efficiently among competing translations and locate those with high English fluency.

  16. Problem Based Game Design

    DEFF Research Database (Denmark)

    Reng, Lars; Schoenau-Fog, Henrik

    2011-01-01

    At Aalborg University’s department of Medialogy, we are utilizing the Problem Based Learning method to encourage students to solve game design problems by pushing the boundaries and designing innovative games. This paper is concerned with describing this method, how students employ it in various...... projects and how they learn to analyse, design, and develop for innovation by using it. We will present various cases to exemplify the approach and focus on how the method engages students and aspires for innovation in digital entertainment and games....

  17. The effect of silicon and copper-indium-gallium-selenide based solar cell structures and processing on temperature dependent performance losses

    Science.gov (United States)

    Hsieh, Judith

    Temperature dependent current voltage measurements (J-V-T) of solar cells. provide both fundamental and practical information. They give detailed insight into. recombination losses within the device as well as information about module. performance losses at higher outdoor operating temperatures. In this thesis, J-V-T. measurements were applied to two distinctly different types of solar cells: crystalline. silicon heterojunction cells and thin film (AgCu)(InGa)Se2 or ACIGS polycrystalline. cells. Crystalline silicon solar cells with heterojunction structure improve the opencircuit. voltage and efficiency. Interdigitated back contact (IBC) Si solar cells obtain a. higher short-circuit current and fill factor compared to front heterojunction (FHJ) solar. cells. ACIGS solar cells have shown higher efficiencies at wider bandgap compared to. the baseline CIGS solar cells. Two high open-circuit voltage CIGS solar cells are. included and compared with ACIGS solar cells. In this thesis, the impact of different. types of solar cells structure and fabrication on temperature dependent performance. losses will be discussed. Devices with higher bandgap are predicted to have higher. open-circuit voltage and lower temperature coefficient of maximum power output. (Pmax). The correlation between temperature coefficient of Pmax and open-circuit. voltage can be found in Si FHJ cells but not Si IBC or ACIGS cells. However, ACIGS. cells show an inverse correlation between temperature coefficient of Pmax and bandgap. as expected. Analysis of diode quality factor and other parameters are interpreted. Sshape. J-V curve can reduce the device's fill factor with a relative high series resistance. This phenomenon tends to occur in FHJ cells rather than IBC at low temperature. Light-dark crossover and roll over effects are commonly seen in ACIGS cells and the. anomaly is enhanced at lower temperature. Most of FHJ and IBC cells obtain the. ideality factor between 1 and 2 while some of ACIGS

  18. Moon base reactor system

    Science.gov (United States)

    Chavez, H.; Flores, J.; Nguyen, M.; Carsen, K.

    1989-01-01

    The objective of our reactor design is to supply a lunar-based research facility with 20 MW(e). The fundamental layout of this lunar-based system includes the reactor, power conversion devices, and a radiator. The additional aim of this reactor is a longevity of 12 to 15 years. The reactor is a liquid metal fast breeder that has a breeding ratio very close to 1.0. The geometry of the core is cylindrical. The metallic fuel rods are of beryllium oxide enriched with varying degrees of uranium, with a beryllium core reflector. The liquid metal coolant chosen was natural lithium. After the liquid metal coolant leaves the reactor, it goes directly into the power conversion devices. The power conversion devices are Stirling engines. The heated coolant acts as a hot reservoir to the device. It then enters the radiator to be cooled and reenters the Stirling engine acting as a cold reservoir. The engines' operating fluid is helium, a highly conductive gas. These Stirling engines are hermetically sealed. Although natural lithium produces a lower breeding ratio, it does have a larger temperature range than sodium. It is also corrosive to steel. This is why the container material must be carefully chosen. One option is to use an expensive alloy of cerbium and zirconium. The radiator must be made of a highly conductive material whose melting point temperature is not exceeded in the reactor and whose structural strength can withstand meteor showers.

  19. Model Based Definition

    Science.gov (United States)

    Rowe, Sidney E.

    2010-01-01

    In September 2007, the Engineering Directorate at the Marshall Space Flight Center (MSFC) created the Design System Focus Team (DSFT). MSFC was responsible for the in-house design and development of the Ares 1 Upper Stage and the Engineering Directorate was preparing to deploy a new electronic Configuration Management and Data Management System with the Design Data Management System (DDMS) based upon a Commercial Off The Shelf (COTS) Product Data Management (PDM) System. The DSFT was to establish standardized CAD practices and a new data life cycle for design data. Of special interest here, the design teams were to implement Model Based Definition (MBD) in support of the Upper Stage manufacturing contract. It is noted that this MBD does use partially dimensioned drawings for auxiliary information to the model. The design data lifecycle implemented several new release states to be used prior to formal release that allowed the models to move through a flow of progressive maturity. The DSFT identified some 17 Lessons Learned as outcomes of the standards development, pathfinder deployments and initial application to the Upper Stage design completion. Some of the high value examples are reviewed.

  20. Droplet based microfluidics

    Science.gov (United States)

    Seemann, Ralf; Brinkmann, Martin; Pfohl, Thomas; Herminghaus, Stephan

    2012-01-01

    Droplet based microfluidics is a rapidly growing interdisciplinary field of research combining soft matter physics, biochemistry and microsystems engineering. Its applications range from fast analytical systems or the synthesis of advanced materials to protein crystallization and biological assays for living cells. Precise control of droplet volumes and reliable manipulation of individual droplets such as coalescence, mixing of their contents, and sorting in combination with fast analysis tools allow us to perform chemical reactions inside the droplets under defined conditions. In this paper, we will review available drop generation and manipulation techniques. The main focus of this review is not to be comprehensive and explain all techniques in great detail but to identify and shed light on similarities and underlying physical principles. Since geometry and wetting properties of the microfluidic channels are crucial factors for droplet generation, we also briefly describe typical device fabrication methods in droplet based microfluidics. Examples of applications and reaction schemes which rely on the discussed manipulation techniques are also presented, such as the fabrication of special materials and biophysical experiments.

  1. Challenge Based Innovation gala

    CERN Document Server

    CERN. Geneva; Utriainen, Tuuli Maria; Toivonen, Harri; Nordberg, Markus

    2014-01-01

    Challenge Based Innovation gala   There’s a new experiment starting in CERN called IdeaLab where we work together with detector R&D researchers to help them to bridge their knowledge into a more human, societally oriented context. Currently we are located in B153, but will move our activities to a new facility next to the Globe in May 2014. One of our first pilot projects is a 5 month course CBI (Challenge Based Innovation) where two multidisciplinary student teams join forces with Edusafe & TALENT projects at CERN. Their goal is to discover what kind of tools for learning could be created in collaboration with the two groups. After months of user interviews and low resolution prototyping they are ready to share the results with us in the form of an afternoon gala. We warmly welcome you to join us to see the students' results and experience the prototypes they have conceived. The event is in three parts, you are welcome to visit all of them,...

  2. Design Based Wilderness Education

    Directory of Open Access Journals (Sweden)

    Christopher R. Saulnier

    2015-02-01

    Full Text Available The Massachusetts Institute of Technology (MIT has been collaborating since 2010 with the Singapore Ministry of Education to help develop the Singapore University of Technology and Design (SUTD. One element of this collaboration, the Global Leadership Program (GLP, aims to provide SUTD students with the opportunity to interact with the MIT community and experience MIT’s academic culture. During GLP students participate in a program designed to develop leadership ability while also increasing their understanding of engineering science and design thinking. This paper introduces a curriculum combining the pedagogies of design-based learning and wilderness education that was implemented in the summer of 2014 to holistically address the development of these three competencies. Through design-based learning activities, both for and in a natural environment, students were encouraged to develop competencies in engineering science and engineering design while exploring the diverse attributes essential for success as an engineer. This paper examines the results of a retrospective post-then-pre survey administered to the participants upon completion of the program to explore the effects of the program on the development of professional engineering competencies. We find a statistically significant increase in items associated with Individual Leadership Skill, Group Leadership Skill and the role of Society and the Economy. These results are triangulated with student exit interviews and instructor observations.

  3. Knowledge Based Economy Assessment

    Directory of Open Access Journals (Sweden)

    Madalina Cristina Tocan

    2012-12-01

    Full Text Available The importance of knowledge-based economy (KBE in the XXI century isevident. In the article the reflection of knowledge on economy is analyzed. The main point is targeted to the analysis of characteristics of knowledge expression in economy and to the construction of structure of KBE expression. This allows understanding the mechanism of functioning of knowledge economy. Theauthors highlight the possibility to assess the penetration level of KBE which could manifest itself trough the existence of products of knowledge expression which could be created in acquisition, creation, usage and development of them. The latter phenomenon is interpreted as knowledge expression characteristics: economic and social context, human resources, ICT, innovative business and innovation policy. The reason for this analysis was based on the idea that in spite of the knowledge economy existence in all developed World countries adefinitive, universal list of indicators for mapping and measuring the KBE does not yet exists. Knowledge Expression Assessment Models are presented in the article.

  4. Droplet based microfluidics.

    Science.gov (United States)

    Seemann, Ralf; Brinkmann, Martin; Pfohl, Thomas; Herminghaus, Stephan

    2012-01-01

    Droplet based microfluidics is a rapidly growing interdisciplinary field of research combining soft matter physics, biochemistry and microsystems engineering. Its applications range from fast analytical systems or the synthesis of advanced materials to protein crystallization and biological assays for living cells. Precise control of droplet volumes and reliable manipulation of individual droplets such as coalescence, mixing of their contents, and sorting in combination with fast analysis tools allow us to perform chemical reactions inside the droplets under defined conditions. In this paper, we will review available drop generation and manipulation techniques. The main focus of this review is not to be comprehensive and explain all techniques in great detail but to identify and shed light on similarities and underlying physical principles. Since geometry and wetting properties of the microfluidic channels are crucial factors for droplet generation, we also briefly describe typical device fabrication methods in droplet based microfluidics. Examples of applications and reaction schemes which rely on the discussed manipulation techniques are also presented, such as the fabrication of special materials and biophysical experiments.

  5. Constraint-based reachability

    Directory of Open Access Journals (Sweden)

    Arnaud Gotlieb

    2013-02-01

    Full Text Available Iterative imperative programs can be considered as infinite-state systems computing over possibly unbounded domains. Studying reachability in these systems is challenging as it requires to deal with an infinite number of states with standard backward or forward exploration strategies. An approach that we call Constraint-based reachability, is proposed to address reachability problems by exploring program states using a constraint model of the whole program. The keypoint of the approach is to interpret imperative constructions such as conditionals, loops, array and memory manipulations with the fundamental notion of constraint over a computational domain. By combining constraint filtering and abstraction techniques, Constraint-based reachability is able to solve reachability problems which are usually outside the scope of backward or forward exploration strategies. This paper proposes an interpretation of classical filtering consistencies used in Constraint Programming as abstract domain computations, and shows how this approach can be used to produce a constraint solver that efficiently generates solutions for reachability problems that are unsolvable by other approaches.

  6. Solution-Processing of Chalcogenide Nanoparticles and Thin Films for Photovoltaic Applications

    OpenAIRE

    Carreté, Àlex

    2015-01-01

    [eng] Thin film solar cells based on direct band gap semiconductors have attracted much research during last decades. Thin film technologies are currently commercial and display record power conversion efficiencies up to 20% at the laboratory scale. However, typical direct band gap semiconductors, CdTe and CuIn1-xGaxS2 (CIGS), content scarce and/or toxic elements such as In, Ga or Cd. An alternative to these materials is Cu2ZnSnS4 (CZTS), formed by abundant and non toxic elements. CZTS i...

  7. Problem-based Learning in a Competency-based World.

    Science.gov (United States)

    Bechtel, Gregory A.; Davidhizar, Ruth; Bradshaw, Martha J.

    1999-01-01

    Problem-based learning emphasizes critical thinking and clinical judgment. Competency-based education focuses on clinical competence. A merger of the two in nursing education could generate higher levels of inquiry and more expert clinicians. (SK)

  8. Watershed based intelligent scissors.

    Science.gov (United States)

    Wieclawek, W; Pietka, E

    2015-07-01

    Watershed based modification of intelligent scissors has been developed. This approach requires a preprocessing phase with anisotropic diffusion to reduce subtle edges. Then, the watershed transform enhances the corridors. Finally, a roaming procedure, developed in this study, delineates the edge selected by a user. Due to a very restrictive set of pixels, subjected to the analysis, this approach significantly reduces the computational complexity. Moreover, the accuracy of the algorithm performance makes often one click point to be sufficient for one edge delineation. The method has been evaluated on structures as different in shape and appearance as the retina layers in OCT exams, chest and abdomen in CT and knee in MR studies. The accuracy is comparable with the traditional Life-Wire approach, whereas the analysis time decreases due to the reduction of the user interaction and number of pixels processed by the method.

  9. Bases para proyectiles dirigidos

    Directory of Open Access Journals (Sweden)

    Editorial, Equipo

    1959-03-01

    Full Text Available Aunque actualmente no se ha llegado a una línea general de métodos o sistemas que gobiernen un tipo característico de rampa y servicios auxiliares necesarios para el lanzamiento al espacio de proyectiles dirigidos a grandes alturas y distancias, las experiencias obtenidas en diferentes ensayos, utilizando distintos tipos de proyectiles y trayectorias balísticas, han sentado toda una serie de procedimientos, datos y conclusiones de gran valor balístico que, aun teniendo en cuenta la continua evolución del proyectil, sus formas, combustibles y alcances, se conocen ya, con bastante aproximación, las condiciones mínimas que ha de reunir una base dedicada a este tipo de lanzamientos.

  10. Ferroelectrics based absorbing layers

    Science.gov (United States)

    Hao, Jianping; Sadaune, Véronique; Burgnies, Ludovic; Lippens, Didier

    2014-07-01

    We show that ferroelectrics-based periodic structure made of BaSrTiO3 (BST) cubes, arrayed onto a metal plate with a thin dielectric spacer film exhibit a dramatic enhancement of absorbance with value close to unity. The enhancement is found around the Mie magnetic resonance of the Ferroelectrics cubes with the backside metal layer stopping any transmitted waves. It also involves quasi-perfect impedance matching resulting in reflection suppression via simultaneous magnetic and electrical activities. In addition, it was shown numerically the existence of a periodicity optimum, which is explained from surface waves analysis along with trade-off between the resonance damping and the intrinsic loss of ferroelectrics cubes. An experimental verification in a hollow waveguide configuration with a good comparison with full-wave numerical modelling is at last reported by measuring the scattering parameters of single and dual BST cubes schemes pointing out coupling effects for densely packed structures.

  11. Base isolation: Fresh insight

    Energy Technology Data Exchange (ETDEWEB)

    Shustov, V.

    1993-07-15

    The objective of the research is a further development of the engineering concept of seismic isolation. Neglecting the transient stage of seismic loading results in a widespread misjudgement: The force of resistance associated with velocity is mostly conceived as a source of damping vibrations, though it is an active force at the same time, during an earthquake type excitation. For very pliant systems such as base isolated structures with relatively low bearing stiffness and with artificially added heavy damping mechanism, the so called `damping`` force may occur even the main pushing force at an earthquake. Thus, one of the two basic pillars of the common seismic isolation philosophy, namely, the doctrine of usefulness and necessity of a strong damping mechanism, is turning out to be a self-deception, sometimes even jeopardizing the safety of structures and discrediting the very idea of seismic isolation. There is a way out: breaking with damping dependancy.

  12. Touching base with OPERA

    CERN Document Server

    CERN Bulletin

    2011-01-01

    Three seminars – at CERN, at Gran Sasso and in Japan – and an article calling for the scrutiny of the scientific community: the OPERA Collaboration opened its research publicly. In addition to huge press coverage, this triggered welcome reactions from colleagues around the world, many of whom will attempt to independently interpret and reproduce the measurement. OPERA’s Spokesperson touches base with the Bulletin.   The CERN Main Auditorium was crowded as OPERA Physics co-ordinator Dario Autiero presented the results of their research (23 September 2011). According to the OPERA strategy, the results of the measurements are in the hands of the scientific community and, as for any other scientific result, several months will be needed before other groups will be able to perform an independent measurement. In the meantime, the OPERA Collaboration is dealing with an avalanche of emails from the scientific community, members of the general public, and the press. &...

  13. Pitch Based Sound Classification

    DEFF Research Database (Denmark)

    Nielsen, Andreas Brinch; Hansen, Lars Kai; Kjems, U

    2006-01-01

    A sound classification model is presented that can classify signals into music, noise and speech. The model extracts the pitch of the signal using the harmonic product spectrum. Based on the pitch estimate and a pitch error measure, features are created and used in a probabilistic model with soft......-max output function. Both linear and quadratic inputs are used. The model is trained on 2 hours of sound and tested on publicly available data. A test classification error below 0.05 with 1 s classification windows is achieved. Further more it is shown that linear input performs as well as a quadratic......, and that even though classification gets marginally better, not much is achieved by increasing the window size beyond 1 s....

  14. Surface Plasmon Based Spectrometer

    Science.gov (United States)

    Wig, Andrew; Passian, Ali; Boudreaux, Philip; Ferrell, Tom

    2008-03-01

    A spectrometer that uses surface plasmon excitation in thin metal films to separate light into its component wavelengths is described. The use of surface plasmons as a dispersive medium sets this spectrometer apart from prism, grating, and interference based variants and allows for the miniaturization of this device. Theoretical and experimental results are presented for two different operation models. In the first case surface plasmon tunneling in the near field is used to provide transmission spectra of different broad band-pass, glass filters across the visible wavelength range with high stray-light rejection at low resolution as well as absorption spectra of chlorophyll extracted from a spinach leaf. The second model looks at the far field components of surface plasmon scattering.

  15. Space-based detectors

    DEFF Research Database (Denmark)

    Sesana, A.; Weber, W. J.; Killow, C. J.;

    2014-01-01

    The parallel session C5 on Space-Based Detectors gave a broad overview over the planned space missions related to gravitational wave detection. Overviews of the revolutionary science to be expected from LISA was given by Alberto Sesana and Sasha Buchman. The launch of LISA Pathfinder (LPF...... bench of LPF was presented by Christian Killow and the performance of the LPF optical metrology system by Paul McNamara. While LPF will not yet be sensitive to gravitational waves, it may nevertheless be used to explore fundamental physics questions, which was discussed by Michele Armano. Some parts....... Using atom interferometry for gravitational wave detection has also been recently proposed, and it was critically reviewed by Peter Bender. In the nearer future, the launch of GRACE Follow-On (for Earth gravity observation) is scheduled for 2017, and it will include a Laser Ranging Interferometer...

  16. PROcess Based Diagnostics PROBE

    Science.gov (United States)

    Clune, T.; Schmidt, G.; Kuo, K.; Bauer, M.; Oloso, H.

    2013-01-01

    Many of the aspects of the climate system that are of the greatest interest (e.g., the sensitivity of the system to external forcings) are emergent properties that arise via the complex interplay between disparate processes. This is also true for climate models most diagnostics are not a function of an isolated portion of source code, but rather are affected by multiple components and procedures. Thus any model-observation mismatch is hard to attribute to any specific piece of code or imperfection in a specific model assumption. An alternative approach is to identify diagnostics that are more closely tied to specific processes -- implying that if a mismatch is found, it should be much easier to identify and address specific algorithmic choices that will improve the simulation. However, this approach requires looking at model output and observational data in a more sophisticated way than the more traditional production of monthly or annual mean quantities. The data must instead be filtered in time and space for examples of the specific process being targeted.We are developing a data analysis environment called PROcess-Based Explorer (PROBE) that seeks to enable efficient and systematic computation of process-based diagnostics on very large sets of data. In this environment, investigators can define arbitrarily complex filters and then seamlessly perform computations in parallel on the filtered output from their model. The same analysis can be performed on additional related data sets (e.g., reanalyses) thereby enabling routine comparisons between model and observational data. PROBE also incorporates workflow technology to automatically update computed diagnostics for subsequent executions of a model. In this presentation, we will discuss the design and current status of PROBE as well as share results from some preliminary use cases.

  17. Base Research Program

    Energy Technology Data Exchange (ETDEWEB)

    Everett Sondreal; John Hendrikson

    2009-03-31

    In June 2009, the Energy & Environmental Research Center (EERC) completed 11 years of research under the U.S. Department of Energy (DOE) Base Cooperative Agreement No. DE-FC26-98FT40320 funded through the Office of Fossil Energy (OFE) and administered at the National Energy Technology Laboratory (NETL). A wide range of diverse research activities were performed under annual program plans approved by NETL in seven major task areas: (1) resource characterization and waste management, (2) air quality assessment and control, (3) advanced power systems, (4) advanced fuel forms, (5) value-added coproducts, (6) advanced materials, and (7) strategic studies. This report summarizes results of the 67 research subtasks and an additional 50 strategic studies. Selected highlights in the executive summary illustrate the contribution of the research to the energy industry in areas not adequately addressed by the private sector alone. During the period of performance of the agreement, concerns have mounted over the impact of carbon emissions on climate change, and new programs have been initiated by DOE to ensure that fossil fuel resources along with renewable resources can continue to supply the nation's transportation fuel and electric power. The agreement has addressed DOE goals for reductions in CO{sub 2} emissions through efficiency, capture, and sequestration while expanding the supply and use of domestic energy resources for energy security. It has further contributed to goals for near-zero emissions from highly efficient coal-fired power plants; environmental control capabilities for SO{sub 2}, NO{sub x}, fine respirable particulate (PM{sub 2.5}), and mercury; alternative transportation fuels including liquid synfuels and hydrogen; and synergistic integration of fossil and renewable resources (e.g., wind-, biomass-, and coal-based electrical generation).

  18. The office based CHIVA

    Directory of Open Access Journals (Sweden)

    Passariello F

    2013-09-01

    Full Text Available Fausto Passariello,1 Stefano Ermini,2 Massimo Cappelli,3 Roberto Delfrate,4 Claude Franceschi5 1Centro Diagnostico Aquarius, Napoli, Italy; 2Private Practice, Grassina, Italy; 3Private Practice, Firenze, Italy; 4Casa di Cure Figlie di Maria, Cremona, Italy; 5Hospital St Joseph, Service d'Explorations Vasculaires, Paris, France Abstract: The cure Conservatrice Hémodynamique de l'Insuffisance Veineuse en Ambulatoire (CHIVA can be office based (OB. The OB-CHIVA protocol is aimed at transferring CHIVA procedures to specialists rooms. The protocol will check the feasibility of OB-CHIVA, data pertaining to recurrence, and will offer the opportunity to study saphenous femoral junction (SFJ stump evolution, the role of the washing vessels and the arch recanalization rate, and gather new data about the effect of the length of the treated saphenous vein. A simplified diagnostic procedure will allow an essential ultrasound examination of the venous net while a schematic and easily readable algorithm guides therapeutic choices. The Riobamba draining crossotomy (RDC tactic is composed of a set of OB procedures. While some of these procedures are, at the moment, only proposals, others are already applied. Devices generally used in ablative procedures such as Light Amplification by Stimulated Emission of Radiation (LASER, radio frequency, steam, and mechanical devices are used in this context to serve to conservative interventions for CHIVA. New techniques have also been proposed for devalvulation and tributary disconnection. Detailed follow-up is necessary in order to determine the effects of therapy and possible disease evolution. Finally, information is added about the informed consent and the ethical considerations of OB-CHIVA research. Keywords: CHIVA, office based procedures, LASER, RF, steam

  19. Loyalty-based management.

    Science.gov (United States)

    Reichheld, F F

    1993-01-01

    Despite a flurry of activities aimed at serving customers better, few companies have systematically revamped their operations with customer loyalty in mind. Instead, most have adopted improvement programs ad hoc, and paybacks haven't materialized. Building a highly loyal customer base must be integral to a company's basic business strategy. Loyalty leaders like MBNA credit cards are successful because they have designed their entire business systems around customer loyalty--a self-reinforcing system in which the company delivers superior value consistently and reinvents cash flows to find and keep high-quality customers and employees. The economic benefits of high customer loyalty are measurable. When a company consistently delivers superior value and wins customer loyalty, market share and revenues go up, and the cost of acquiring new customers goes down. The better economics mean the company can pay workers better, which sets off a whole chain of events. Increased pay boosts employee moral and commitment; as employees stay longer, their productivity goes up and training costs fall; employees' overall job satisfaction, combined with their experience, helps them serve customers better; and customers are then more inclined to stay loyal to the company. Finally, as the best customers and employees become part of the loyalty-based system, competitors are left to survive with less desirable customers and less talented employees. To compete on loyalty, a company must understand the relationships between customer retention and the other parts of the business--and be able to quantify the linkages between loyalty and profits. It involves rethinking and aligning four important aspects of the business: customers, product/service offering, employees, and measurement systems.

  20. DUAL BASES FOR A NEW FAMILY OF GENERALIZED BALL BASES

    Institute of Scientific and Technical Information of China (English)

    Hong-yiWu

    2004-01-01

    This paper presents the dual bases for a new family of generalized Ball curves with a position parameter K, which includes the Bezier curve, generalized Said-Ball curve and some intermediate curves. Using the dual bases, the relative Marsden identity, conversion formulas of bases and control points of various curves are obtained.

  1. CMOS-Based Biosensor Arrays

    CERN Document Server

    Thewes, R; Schienle, M; Hofmann, F; Frey, A; Brederlow, R; Augustyniak, M; Jenkner, M; Eversmann, B; Schindler-Bauer, P; Atzesberger, M; Holzapfl, B; Beer, G; Haneder, T; Hanke, H -C

    2011-01-01

    CMOS-based sensor array chips provide new and attractive features as compared to today's standard tools for medical, diagnostic, and biotechnical applications. Examples for molecule- and cell-based approaches and related circuit design issues are discussed.

  2. Agent-Based Cloud Computing

    OpenAIRE

    Sim, Kwang Mong

    2012-01-01

    Agent-based cloud computing is concerned with the design and development of software agents for bolstering cloud service\\ud discovery, service negotiation, and service composition. The significance of this work is introducing an agent-based paradigm for\\ud constructing software tools and testbeds for cloud resource management. The novel contributions of this work include: 1) developing\\ud Cloudle: an agent-based search engine for cloud service discovery, 2) showing that agent-based negotiatio...

  3. Utilization-Based Congestion Control

    OpenAIRE

    Satoshi Utsumi; Salahuddin Muhammad Salim Zabir

    2012-01-01

    Traditional connection oriented protocols like TCP NewReno perform poorly over wireless links. Theproblem lies in their design assumptions based on loss based congestion control. Various modificationsto loss based congestion control schemes have so far been proposed to overcome the issue. In addition,the comparatively newer family of delay based congestion control mechanisms like Caia-Hamilton Delay(CHD), offer effective solutions for wireless link loss. All these approaches aim at improving ...

  4. ‘"Education-based Research"

    DEFF Research Database (Denmark)

    Degn Johansson, Troels

    This paper lays out a concept of education-based research-the production of research knowledge within the framework of tertiary design education-as an integration of problem-based learning and research-based education. This leads to a critique of reflective practice as the primary way to facilitate...... learning at this level, a discussion of the nature of design problems in the instrumentalist tradition, and some suggestions as to how design studies curricula may facilitate education-based research....

  5. Managing the Gap between Curriculum Based and Problem Based Learning

    DEFF Research Database (Denmark)

    Bygholm, Ann; Buus, Lillian

    2009-01-01

    Traditionally there has been a clear distinction between curriculum based and problem based approaches to accomplish learning. Preferred approaches depend of course on conviction, culture, traditions and also on the specific learning situation. We will argue that it is not a question of either....../or but rather both/and. In this paper we describe an approach to design and delivery of online courses in computer science which on the one hand is based on a specified curriculum and on the other hand gives room for different learning strategies, problem based learning being one of them. We discuss...... the challenges in applying problem based learning strategies in a context where several universities, with different cultures of teaching, collaboratively develop and deliver online courses. We present a pedagogical framework embracing both problem based and curriculum based strategies and show how we used...

  6. Identity-based ring signature scheme based on quadratic residues

    Institute of Scientific and Technical Information of China (English)

    Xiong Hu; Qin Zhiguang; Li Fagen

    2009-01-01

    Identity-based (ID-based) ring signature has drawn great concerns in recent years and many ID-based ring signature schemes have been proposed until now. Unfortunately, all of these ID-based ring signatures are constructed from bilinear pairings, a powerful but computationally expensive primitive. Hence, ID-based ring signature without pairing is of great interest in the field of cryptography. In this paper, the authors firstly propose an ID-based ring signature scheme based on quadratic residues. The proposed scheme is proved to be existentially unforgeable against adaptive chosen message-and-identity attack under the random oracle model, assuming the hardness of factoring. The proposed scheme is more efficient than those which are constructed from bilinear pairings.

  7. Memory-Based Shallow Parsing

    NARCIS (Netherlands)

    Tjong Kim Sang, E.F.

    2002-01-01

    We present memory-based learning approaches to shallow parsing and apply these to five tasks: base noun phrase identification, arbitrary base phrase recognition, clause detection, noun phrase parsing and full parsing. We use feature selection techniques and system combination methods for improving t

  8. Base Camp Design Simulation Training

    Science.gov (United States)

    2011-07-01

    The Army needs officers and noncommissioned officers with requisite base camp competencies. The Army’s Field Manual (FM) 3-34.400 defines a Base Camp...reason, we designed a 600-man base camp on VBS2TM from an AutoCAD diagram found on the Theater Construction Management System (version 3.2). Known

  9. Securing web-based exams

    NARCIS (Netherlands)

    Sessink, O.D.T.; Beeftink, H.H.; Tramper, J.; Hartog, R.J.M.

    2004-01-01

    Learning management systems may offer web-based exam facilities. Such facilities entail a higher risk to exams fraud than traditional paper-based exams. The article discusses security issues with web-based exams, and proposes precautionary measures to reduce the risks. A security model is presented

  10. Based on Channel Characteristics

    Directory of Open Access Journals (Sweden)

    Zhuo Hao

    2013-01-01

    Full Text Available A number of key agreement schemes based on wireless channel characteristics have been proposed recently. However, previous key agreement schemes require that two nodes which need to agree on a key are within the communication range of each other. Hence, they are not suitable for multihop wireless networks, in which nodes do not always have direct connections with each other. In this paper, we first propose a basic multihop key agreement scheme for wireless ad hoc networks. The proposed basic scheme is resistant to external eavesdroppers. Nevertheless, this basic scheme is not secure when there exist internal eavesdroppers or Man-in-the-Middle (MITM adversaries. In order to cope with these adversaries, we propose an improved multihop key agreement scheme. We show that the improved scheme is secure against internal eavesdroppers and MITM adversaries in a single path. Both performance analysis and simulation results demonstrate that the improved scheme is efficient. Consequently, the improved key agreement scheme is suitable for multihop wireless ad hoc networks.

  11. RF Based Spy

    Directory of Open Access Journals (Sweden)

    Robot Prerna Jain

    2014-04-01

    Full Text Available The intention of this paper is to reduce human victims in terrorist attack such as 26/11. So this problem can be overcome by designing the RF based spy robot which involves wireless camera. so that from this we can examine rivals when it required. This robot can quietly enter into enemy area and sends us the information via wireless camera. On the other hand one more feature is added in this robot that is colour sensor. Colour sensor senses the colour of surface and according to that robot will change its colour. Because of this feature this robot can’t easily detected by enemies. The movement of this robot is wirelessly controlled by a hand held RF transmitter to send commands to the RF receiver mounted on the moving robot. Since human life is always Valueable, these robots are the substitution of soldiers in war areas. This spy robot can also be used in star hotels, shopping malls, jewelry show rooms, etc where there can be threat from intruders or terrorists.

  12. Alphavirus-based vaccines.

    Science.gov (United States)

    Lundstrom, Kenneth

    2014-06-16

    Alphavirus vectors have demonstrated high levels of transient heterologous gene expression both in vitro and in vivo and, therefore, possess attractive features for vaccine development. The most commonly used delivery vectors are based on three single-stranded encapsulated alphaviruses, namely Semliki Forest virus, Sindbis virus and Venezuelan equine encephalitis virus. Alphavirus vectors have been applied as replication-deficient recombinant viral particles and, more recently, as replication-proficient particles. Moreover, in vitro transcribed RNA, as well as layered DNA vectors have been applied for immunization. A large number of highly immunogenic viral structural proteins expressed from alphavirus vectors have elicited strong neutralizing antibody responses in multispecies animal models. Furthermore, immunization studies have demonstrated robust protection against challenges with lethal doses of virus in rodents and primates. Similarly, vaccination with alphavirus vectors expressing tumor antigens resulted in prophylactic protection against challenges with tumor-inducing cancerous cells. As certain alphaviruses, such as Chikungunya virus, have been associated with epidemics in animals and humans, attention has also been paid to the development of vaccines against alphaviruses themselves. Recent progress in alphavirus vector development and vaccine technology has allowed conducting clinical trials in humans.

  13. Alphavirus-Based Vaccines

    Directory of Open Access Journals (Sweden)

    Kenneth Lundstrom

    2014-06-01

    Full Text Available Alphavirus vectors have demonstrated high levels of transient heterologous gene expression both in vitro and in vivo and, therefore, possess attractive features for vaccine development. The most commonly used delivery vectors are based on three single-stranded encapsulated alphaviruses, namely Semliki Forest virus, Sindbis virus and Venezuelan equine encephalitis virus. Alphavirus vectors have been applied as replication-deficient recombinant viral particles and, more recently, as replication-proficient particles. Moreover, in vitro transcribed RNA, as well as layered DNA vectors have been applied for immunization. A large number of highly immunogenic viral structural proteins expressed from alphavirus vectors have elicited strong neutralizing antibody responses in multispecies animal models. Furthermore, immunization studies have demonstrated robust protection against challenges with lethal doses of virus in rodents and primates. Similarly, vaccination with alphavirus vectors expressing tumor antigens resulted in prophylactic protection against challenges with tumor-inducing cancerous cells. As certain alphaviruses, such as Chikungunya virus, have been associated with epidemics in animals and humans, attention has also been paid to the development of vaccines against alphaviruses themselves. Recent progress in alphavirus vector development and vaccine technology has allowed conducting clinical trials in humans.

  14. Biosensors based on cantilevers.

    Science.gov (United States)

    Alvarez, Mar; Carrascosa, Laura G; Zinoviev, Kiril; Plaza, Jose A; Lechuga, Laura M

    2009-01-01

    Microcantilevers based-biosensors are a new label-free technique that allows the direct detection of biomolecular interactions in a label-less way and with great accuracy by translating the biointeraction into a nanomechanical motion. Low cost and reliable standard silicon technologies are widely used for the fabrication of cantilevers with well-controlled mechanical properties. Over the last years, the number of applications of these sensors has shown a fast growth in diverse fields, such as genomic or proteomic, because of the biosensor flexibility, the low sample consumption, and the non-pretreated samples required. In this chapter, we report a dedicated design and a fabrication process of highly sensitive microcantilever silicon sensors. We will describe as well an application of the device in the environmental field showing the immunodetection of an organic toxic pesticide as an example. The cantilever biofunctionalization process and the subsequent pesticide determination are detected in real time by monitoring the nanometer-scale bending of the microcantilever due to a differential surface stress generated between both surfaces of the device.

  15. Lunar base construction requirements

    Science.gov (United States)

    Jolly, Steve; Helleckson, Brent

    1990-01-01

    The following viewgraph presentation is a review of the Lunar Base Constructibility Study carried out in the spring and summer of 1990. The objective of the study was to develop a method for evaluating the constructibility of Phase A proposals to build facilities on orbit or on extraterrestrial surfaces. Space construction was broadly defined as all forms of assembly, disassembly, connection, disconnection, deployment, stowage, excavation, emplacement, activation, test, transportation, etc., required to create facilities in orbit and on the surfaces of other celestial bodies. It was discovered that decisions made in the face of stated and unstated assumptions early in the design process (commonly called Phase A) can lock in non-optimal construction methods. Often, in order to construct the design, alterations must be made to the design during much later phases of the project. Such 'fixes' can be very difficult, expensive, or perhaps impossible. Assessing constructibility should thus be a part of the iterative design process, starting with the Phase A studies and continuing through production. This study assumes that there exists a minimum set of key construction requirements (i.e., questions whose answers form the set of discriminators) that must be implied or specified in order to assess the constructibility of the design. This set of construction requirements constitutes a 'constructibility filter' which then becomes part of the iterative design process. Five inherently different, dichotomous design reference missions were used in the extraction of these requirements to assure the depth and breath of the list.

  16. Holography based super resolution

    Science.gov (United States)

    Hussain, Anwar; Mudassar, Asloob A.

    2012-05-01

    This paper describes the simulation of a simple technique of superresolution based on holographic imaging in spectral domain. The input beam assembly containing 25 optical fibers with different orientations and positions is placed to illuminate the object in the 4f optical system. The position and orientation of each fiber is calculated with respect to the central fiber in the array. The positions and orientations of the fibers are related to the shift of object spectrum at aperture plane. During the imaging process each fiber is operated once in the whole procedure to illuminate the input object transparency which gives shift to the object spectrum in the spectral domain. This shift of the spectrum is equal to the integral multiple of the pass band aperture width. During the operation of single fiber (ON-state) all other fibers are in OFF-state at that time. The hologram recorded by each fiber at the CCD plane is stored in computer memory. At the end of illumination process total 25 holograms are recorded by the whole fiber array and by applying some post processing and specific algorithm single super resolved image is obtained. The superresolved image is five times better than the band-limited image. The work is demonstrated using computer simulation only.

  17. Explanation-Based Auditing

    CERN Document Server

    Fabbri, Daniel

    2011-01-01

    To comply with emerging privacy laws and regulations, it has become common for applications like electronic health records systems (EHRs) to collect access logs, which record each time a user (e.g., a hospital employee) accesses a piece of sensitive data (e.g., a patient record). Using the access log, it is easy to answer simple queries (e.g., Who accessed Alice's medical record?), but this often does not provide enough information. In addition to learning who accessed their medical records, patients will likely want to understand why each access occurred. In this paper, we introduce the problem of generating explanations for individual records in an access log. The problem is motivated by user-centric auditing applications, and it also provides a novel approach to misuse detection. We develop a framework for modeling explanations which is based on a fundamental observation: For certain classes of databases, including EHRs, the reason for most data accesses can be inferred from data stored elsewhere in the da...

  18. Mixture Based Outlier Filtration

    Directory of Open Access Journals (Sweden)

    P. Pecherková

    2006-01-01

    Full Text Available Success/failure of adaptive control algorithms – especially those designed using the Linear Quadratic Gaussian criterion – depends on the quality of the process data used for model identification. One of the most harmful types of process data corruptions are outliers, i.e. ‘wrong data’ lying far away from the range of real data. The presence of outliers in the data negatively affects an estimation of the dynamics of the system. This effect is magnified when the outliers are grouped into blocks. In this paper, we propose an algorithm for outlier detection and removal. It is based on modelling the corrupted data by a two-component probabilistic mixture. The first component of the mixture models uncorrupted process data, while the second models outliers. When the outlier component is detected to be active, a prediction from the uncorrupted data component is computed and used as a reconstruction of the observed data. The resulting reconstruction filter is compared to standard methods on simulated and real data. The filter exhibits excellent properties, especially in the case of blocks of outliers. 

  19. AUGMENTED REALITY BASED ASSISTANCE

    Directory of Open Access Journals (Sweden)

    N.R.Raajan

    2013-04-01

    Full Text Available The concept of Augmented Reality can be explained as a superimposition of computer generated two dimensional or three dimensional objects over the real time scene acquired into thecapturing device. Thus Augmented Reality adds additional information to the real scene and this can be implemented with the help of markers. The development of the application is simple and easier in case of AR. This idea is extended to the development of Augmented Reality based book that act as a tour guide. This travel guide can give all the basic information regarding the necessities of a finer travel around the places of the destinations. The application will detect the markers found in the real scene and superimpose them with multimedia data giving enormous information. The application can also be made to redirect to the web links for easy access of certain other utilities by interaction. The same idea can also be utilized in engineering laboratories to understand the working of the circuit by visualizing the working of the same circuit where the diagram itself can be used as a marker and thus enhancing the self learning among the students.

  20. Shear Bond Strength of Bracket Bases to Adhesives Based on Bracket Base Design

    Science.gov (United States)

    2016-04-13

    bracket compared to the surface of the substrate. Recent research and development have resulted in the production of various bracket base designs other...designs has been offered by ODP’s state of the art Anchor-Lock TM Pad which claims to take bonding to a whole new level. With this bracket, the base ...FUTURE RESEARCH When metal bracket bases are debonded, the site of failure occurs predominately at the adhesive- base interface. This failure site

  1. Cocktails of paste coatings for performance enhancement of CuInGaS(2) thin-film solar cells.

    Science.gov (United States)

    An, Hee Sang; Cho, Yunae; Park, Se Jin; Jeon, Hyo Sang; Hwang, Yun Jeong; Kim, Dong-Wook; Min, Byoung Koun

    2014-01-22

    To fabricate low-cost and printable wide-bandgap CuInxGa1-xS2 (CIGS) thin-film solar cells, a method based on a precursor solution was developed. In particular, under this method, multiple coatings with two pastes with different properties (e.g., viscosity) because of the different binder materials added were applied. Paste A could form a thin, dense layer enabling a high-efficiency solar cell but required several coating and drying cycles for the desired film thickness. On the other hand, paste B could easily form one-micrometer-thick films by means of a one-time spin-coating process but the porous microstructure limited the solar cell performance. Three different configurations of the CIGS films (A + B, B + A, and A + B + A) were realized by multiple coatings with the two pastes to find the optimal stacking configuration for a combination of the advantages of each paste. Solar cell devices using these films showed a notable difference in their photovoltaic characteristics. The bottom dense layer increased the minority carrier diffusion length and enhanced the short-circuit current. The top dense layer could suppress interface recombination but exhibited a low optical absorption, thereby decreasing the photocurrent. As a result, the A + B configuration could be suggested as a desirable simple stacking structure. The solar cell with A + B coating showed a highly improved efficiency (4.66%) compared to the cell with a film prepared by paste B only (2.90%), achieved by simple insertion of a single thin (200 nm), dense layer between the Mo back contact and a thick porous CIGS layer.

  2. Workplace Based Assessment in Psychiatry

    Directory of Open Access Journals (Sweden)

    Ayse Devrim Basterzi

    2009-11-01

    Full Text Available Workplace based assessment refers to the assessment of working practices based on what doctors actually do in the workplace, and is predominantly carried out in the workplace itself. Assessment drives learning and it is therefore essential that workplace-based assessment focuses on important attributes rather than what is easiest to assess. Workplacebased assessment is usually competency based. Workplace based assesments may well facilitate and enhance various aspects of educational supervisions, including its structure, frequency and duration etc. The structure and content of workplace based assesments should be monitored to ensure that its benefits are maximised by remaining tailored to individual trainees' needs. Workplace based assesment should be used for formative and summative assessments. Several formative assessment methods have been developed for use in the workplace such as mini clinical evaluation exercise (mini-cex, evidence based journal club assesment and case based discussion, multi source feedback etc. This review discusses the need of workplace based assesments in psychiatry graduate education and introduces some of the work place based assesment methods.

  3. Seguridad en bases de datos

    Directory of Open Access Journals (Sweden)

    Heidy Alina Nuevo León

    2011-11-01

    Full Text Available Los sistemas de base de datos son de gran uso, el cual va desde el uso de bases de datos ligeras, bases de datos en tiempo real (en algunas ocasiones obtenida a partir de la optimización de bases de datos relacionales y bases de datos relacionales con potentes gestores como aplicación proveedora del servicio. En el mundo del software libre existen gran cantidad de gestores de bases de datos, entre los que se encuentran mysql, berkeley db, sqlite y postgresql. Este último con gran número de seguidores y de personas de gran nivel en el mundo del desarrollo libre que contribuyen a su propósito.  El presente trabajo tiene como objetivo principal mostrar mediante una investigación los diferentes mecanismos para realizar la configuración de la seguridad para el gestor de base de datos Postgres

  4. Soy-based renoprotection.

    Science.gov (United States)

    McGraw, Nancy J; Krul, Elaine S; Grunz-Borgmann, Elizabeth; Parrish, Alan R

    2016-05-06

    Chronic kidney disease (CKD) is a significant public health problem as risk factors such as advanced age, obesity, hypertension and diabetes rise in the global population. Currently there are no effective pharmacologic treatments for this disease. The role of diet is important for slowing the progression of CKD and managing symptoms in later stages of renal insufficiency. While low protein diets are generally recommended, maintaining adequate levels of intake is critical for health. There is an increasing appreciation that the source of protein may also be important. Soybean protein has been the most extensively studied plant-based protein in subjects with kidney disease and has demonstrated renal protective properties in a number of clinical studies. Soy protein consumption has been shown to slow the decline in estimated glomerular filtration rate and significantly improve proteinuria in diabetic and non-diabetic patients with nephropathy. Soy's beneficial effects on renal function may also result from its impact on certain physiological risk factors for CKD such as dyslipidemia, hypertension and hyperglycemia. Soy intake is also associated with improvements in antioxidant status and systemic inflammation in early and late stage CKD patients. Studies conducted in animal models have helped to identify the underlying molecular mechanisms that may play a role in the positive effects of soy protein on renal parameters in polycystic kidney disease, metabolically-induced kidney dysfunction and age-associated progressive nephropathy. Despite the established relationship between soy and renoprotection, further studies are needed for a clear understanding of the role of the cellular and molecular target(s) of soy protein in maintaining renal function.

  5. Lunar Base Heat Pump

    Science.gov (United States)

    Walker, D.; Fischbach, D.; Tetreault, R.

    1996-01-01

    The objective of this project was to investigate the feasibility of constructing a heat pump suitable for use as a heat rejection device in applications such as a lunar base. In this situation, direct heat rejection through the use of radiators is not possible at a temperature suitable for lde support systems. Initial analysis of a heat pump of this type called for a temperature lift of approximately 378 deg. K, which is considerably higher than is commonly called for in HVAC and refrigeration applications where heat pumps are most often employed. Also because of the variation of the rejection temperature (from 100 to 381 deg. K), extreme flexibility in the configuration and operation of the heat pump is required. A three-stage compression cycle using a refrigerant such as CFC-11 or HCFC-123 was formulated with operation possible with one, two or three stages of compression. Also, to meet the redundancy requirements, compression was divided up over multiple compressors in each stage. A control scheme was devised that allowed these multiple compressors to be operated as required so that the heat pump could perform with variable heat loads and rejection conditions. A prototype heat pump was designed and constructed to investigate the key elements of the high-lift heat pump concept. Control software was written and implemented in the prototype to allow fully automatic operation. The heat pump was capable of operation over a wide range of rejection temperatures and cooling loads, while maintaining cooling water temperature well within the required specification of 40 deg. C +/- 1.7 deg. C. This performance was verified through testing.

  6. Space-based detectors

    Science.gov (United States)

    Sesana, A.; Weber, W. J.; Killow, C. J.; Perreur-Lloyd, M.; Robertson, D. I.; Ward, H.; Fitzsimons, E. D.; Bryant, J.; Cruise, A. M.; Dixon, G.; Hoyland, D.; Smith, D.; Bogenstahl, J.; McNamara, P. W.; Gerndt, R.; Flatscher, R.; Hechenblaikner, G.; Hewitson, M.; Gerberding, O.; Barke, S.; Brause, N.; Bykov, I.; Danzmann, K.; Enggaard, A.; Gianolio, A.; Vendt Hansen, T.; Heinzel, G.; Hornstrup, A.; Jennrich, O.; Kullmann, J.; Møller-Pedersen, S.; Rasmussen, T.; Reiche, J.; Sodnik, Z.; Suess, M.; Armano, M.; Sumner, T.; Bender, P. L.; Akutsu, T.; Sathyaprakash, B. S.

    2014-12-01

    The parallel session C5 on Space-Based Detectors gave a broad overview over the planned space missions related to gravitational wave detection. Overviews of the revolutionary science to be expected from LISA was given by Alberto Sesana and Sasha Buchman. The launch of LISA Pathfinder (LPF) is planned for 2015. This mission and its payload "LISA Technology Package" will demonstrate key technologies for LISA. In this context, reference masses in free fall for LISA, and gravitational physics in general, was described by William Weber, laser interferometry at the pico-metre level and the optical bench of LPF was presented by Christian Killow and the performance of the LPF optical metrology system by Paul McNamara. While LPF will not yet be sensitive to gravitational waves, it may nevertheless be used to explore fundamental physics questions, which was discussed by Michele Armano. Some parts of the LISA technology that are not going to be demonstrated by LPF, but under intensive development at the moment, were presented by Oliver Jennrich and Oliver Gerberding. Looking into the future, Japan is studying the design of a mid-frequency detector called DECIGO, which was discussed by Tomotada Akutsu. Using atom interferometry for gravitational wave detection has also been recently proposed, and it was critically reviewed by Peter Bender. In the nearer future, the launch of GRACE Follow-On (for Earth gravity observation) is scheduled for 2017, and it will include a Laser Ranging Interferometer as technology demonstrator. This will be the first inter-spacecraft laser interferometer and has many aspects in common with the LISA long arm, as discussed by Andrew Sutton.

  7. Nanoparticle-based Sensors

    Directory of Open Access Journals (Sweden)

    V.K. Khanna

    2008-09-01

    Full Text Available Nanoparticles exhibit several unique properties that can be applied to develop chemical and biosensorspossessing desirable features like enhanced sensitivity and lower detection limits. Gold nanoparticles arecoated with sugars tailored to recognise different biological substances. When mixed with a weak solution ofthe sugar-coated nanoparticles, the target substance, e.g., ricin or E.coli, attaches to the sugar, thereby alteringits properties and changing the colour. Spores of bacterium labeled with carbon dots have been found to glowupon illumination when viewed with a confocal microscope. Enzyme/nanoparticle-based optical sensors forthe detection of organophosphate (OP compounds employ nanoparticle-modified fluorescence of an inhibitorof the enzyme to generate the signal for the OP compound detection. Nanoparticles shaped as nanoprisms,built of silver atoms, appear red on exposure to light. These nanoparticles are used as diagnostic labels thatglow when target DNA, e.g., those of anthrax or HIV, are present. Of great importance are tools like goldnanoparticle-enhanced surface-plasmon resonance sensor and silver nanoparticle surface-enhanced portableRaman integrated tunable sensor. Nanoparticle metal oxide chemiresistors using micro electro mechanical systemhotplate are very promising devices for toxic gas sensing. Chemiresistors comprising thin films of nanogoldparticles, encapsulated in monomolecular layers of functionalised alkanethiols, deposited on interdigitatedmicroelectrodes, show resistance changes through reversible absorption of vapours of harmful gases. Thispaper reviews the state-of-the-art sensors for chemical and biological terror agents, indicates their capabilitiesand applications, and presents the future scope of these devices.Defence Science Journal, 2008, 58(5, pp.608-616, DOI:http://dx.doi.org/10.14429/dsj.58.1683

  8. Case-based reasoning: The marriage of knowledge base and data base

    Science.gov (United States)

    Pulaski, Kirt; Casadaban, Cyprian

    1988-01-01

    The coupling of data and knowledge has a synergistic effect when building an intelligent data base. The goal is to integrate the data and knowledge almost to the point of indistinguishability, permitting them to be used interchangeably. Examples given in this paper suggest that Case-Based Reasoning is a more integrated way to link data and knowledge than pure rule-based reasoning.

  9. Improved growth of solution-deposited thin films on polycrystalline Cu(In,Ga)Se{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Witte, Wolfram; Hariskos, Dimitrios [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung Baden-Wuerttemberg (ZSW), 70565, Stuttgart (Germany); Abou-Ras, Daniel [Helmholtz-Zentrum Berlin fuer Materialien und Energie, 14109, Berlin (Germany)

    2016-04-15

    CdS and Zn(O,S) grown by chemical bath deposition (CBD) are well established buffer materials for Cu(In,Ga)Se{sub 2} (CIGS) solar cells. As recently reported, a non-contiguous coverage of CBD buffers on CIGS grains with {112} surfaces can be detected, which was explained in terms of low surface energies of the {112} facets, leading to deteriorated wetting of the chemical solution on the CIGS surface. In the present contribution, we report on the effect of air annealing of CIGS thin films prior to the CBD of CdS and Zn(O,S) layers. In contrast to the growth on the as-grown CIGS layers, these buffer lay- ers grow densely on the annealed CIGS layer, even on grains with {112} surfaces. We explain the different growth behavior by increased surface energies of CIGS grains due to the annealing step, i.e., due to oxidation of the CIGS surface. Reference solar cells were processed and completed by i-ZnO/ZnO:Al layers for CdS and by (Zn,Mg)O/ZnO:Al for Zn(O,S) buffers. For solar cells with both, CdS and Zn(O,S) buffers, air-annealed CIGS films with improved buffer coverage resulted in higher power-conversion efficiencies, as compared with the devices containing as-grown CIGS layers. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Photonic sintering of thin film prepared by dodecylamine capped CuIn{sub x}Ga{sub 1−x}Se{sub 2} nanoparticles for printed photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Manjeet, E-mail: msitbhu@gmail.com; Jiu, Jinting; Sugahara, Tohru; Suganuma, Katsuaki

    2014-08-28

    In this paper, we report solution phase large scale synthesis of monodisperse phase pure CuIn{sub x}Ga{sub 1−x}Se{sub 2} (CIGS) nanoparticles by using dodecylamine as solvent and dispersant. Various compositions of CIGS nanoparticles with different Ga content are synthesized by simply adding different amounts of Ga precursors. The band gap of CIGS nanoparticles can be tuned by changing Ga content. Effort is given to understand the formation pathway of CIGS phase so as to make the synthesis easier for the desired product. High intensity pulsed light technique, which provides extreme local heating, is used to sinter the thin film prepared using these nanoparticles on a Mo–glass surface. A uniformly conductive and dense CIGS film can be prepared by adjusting the energy of light and exposure time. The high intensity light irradiation of the CIGS film leads to diffusion of smaller CIGS nanoparticles to form a particle with larger grain size and thus enables sintering of particles without using high temperature processing. - Highlights: • Large scale synthesis of CuIn{sub x}Ga{sub 1−x}Se{sub 2} (CIGS) is reported. • Dodecylamine is used as surfactant and solvent. • CIGS phase formation mechanism is described. • High intensity pulsed light technique is used to sinter the CIGS film.

  11. Regulation in the face of uncertainty: the evidence on electronic nicotine delivery systems (e-cigarettes

    Directory of Open Access Journals (Sweden)

    Farsalinos KE

    2015-09-01

    Full Text Available Konstantinos E Farsalinos,1,2 Jacques Le Houezec3,4 1Department of Cardiology, Onassis Cardiac Surgery Center, Kallithea, 2Department of Pharmacy, University of Patras, Patras, Greece; 3Division of Epidemiology and Public Health, UK Centre for Tobacco and Alcohol Studies, University of Nottingham, Nottingham, England, UK; 4Addiction Research Unit, INSERM 1178 (Mental and Public Health, Paris, France Abstract: Tobacco smoking is the largest single preventable cause of many chronic diseases and death. Effective treatments exist; however, few smokers use them and most try to quit by themselves. Most of the tobacco cigarette's toxicity is related to the combustion process. Models of harm reduction applied to tobacco suggest that switching from inhalation of combustible products to a noncombustible nicotine delivery product would likely result in a vast reduction in tobacco-related death and illness. Currently available evidence raises no doubt that electronic cigarettes (e-cigs are by far less harmful than smoking (although probably not absolutely safe and have the potential to be the most effective tobacco harm reduction products due to their unique property of resembling smoking and providing satisfaction to the user. A lot of controversy is surrounding e-cigs and their regulation, much of which is based on the precautionary principle. Although monitoring and further research is definitely needed, the arguments used to implement severe restrictions or bans are mostly hypothetical, weakly supported by evidence, and, in some cases, derived from mispresentation or misinterpretation of the study findings. Regulators should keep in mind that the target population is smokers who want to reduce or quit their deadly tobacco consumption. To achieve this goal, smokers should be honestly informed on the relative harmfulness of the different products. E-cigs are not tobacco products and are not used as medications. For this reason, a specific regulatory

  12. The Influence of a Humectant on the Retention by Humans of Solanesol from Cigarette Smoke (Part 1, Propylene Glycol

    Directory of Open Access Journals (Sweden)

    Moldoveanu SC

    2014-12-01

    Full Text Available Propylene glycol (PG is a common humectant added to the tobacco used in cigarettes, and part of this compound is transferred to smoke. The influence of this additive on the retention of solanesol by smokers has been evaluated in the present study for two cigarettes having the same tobacco blend except for the 3% addition of PG on one of them. The cigarette with no PG was a commercial brand, and the experimental one was made using the same tobacco blend as the commercial cigarette, but adding 3% of PG. The construction of the cigarette with 3% PG allowed to match as close as possible the ‘tar’ [as measured by Federal Trade Commission (FTC regimen], pressure drop (open and closed, and nicotine level of the commercial cigarette. The number of human subjects taking the test was ten smokers for each of the two evaluated products. The sample collection was performed from three cigarettes smoked within one hour. The same human subject smoked the regular cigarette and then the one with added PG. The exhaled smoke was collected using a vacuum assisted procedure that avoids strain in exhaling, and the solanesol was analyzed using an high performance liquid chromatography (HPLC technique. The cigarette butts from the smokers were collected and also analyzed for solanesol. The results obtained for the cigarette butts from the smokers were used to calculate the level of solanesol in the smoke delivered to the human subject, based on calibration curves. These curves were generated separately by analyzing the solanesol in smoke and in the cigarette butts obtained by machine smoking under different puffing regimes. Knowing the delivered amount of solanesol and that in the exhaled smoke it was possible to calculate the retention of this compound from mainstream smoke for the two cigarette types. The levels of solanesol delivered to the smoker from Cigarette A was in the range between 350.4 ìg/cig and 504.8 ìg/cig for the cigarette with no PG, and between

  13. Knowledge base verification based on enhanced colored petri net

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Hyun; Seong, Poong Hyun [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1997-12-31

    Verification is a process aimed at demonstrating whether a system meets it`s specified requirements. As expert systems are used in various applications, the knowledge base verification of systems takes an important position. The conventional Petri net approach that has been studied recently in order to verify the knowledge base is found that it is inadequate to verify the knowledge base of large and complex system, such as alarm processing system of nuclear power plant. Thus, we propose an improved method that models the knowledge base as enhanced colored Petri net. In this study, we analyze the reachability and the error characteristics of the knowledge base and apply the method to verification of simple knowledge base. 8 refs., 4 figs. (Author)

  14. Optimal pricing decision model based on activity-based costing

    Institute of Scientific and Technical Information of China (English)

    王福胜; 常庆芳

    2003-01-01

    In order to find out the applicability of the optimal pricing decision model based on conventional costbehavior model after activity-based costing has given strong shock to the conventional cost behavior model andits assumptions, detailed analyses have been made using the activity-based cost behavior and cost-volume-profitanalysis model, and it is concluded from these analyses that the theory behind the construction of optimal pri-cing decision model is still tenable under activity-based costing, but the conventional optimal pricing decisionmodel must be modified as appropriate to the activity-based costing based cost behavior model and cost-volume-profit analysis model, and an optimal pricing decision model is really a product pricing decision model construc-ted by following the economic principle of maximizing profit.

  15. Identity-based signature scheme based on quadratic residues

    Institute of Scientific and Technical Information of China (English)

    CHAI ZhenChuan; CAO ZhenFu; DONG XiaoLei

    2007-01-01

    Identity-based (ID-based) cryptography has drawn great concerns in recent years, and most of ID-based schemes are constructed from bilinear parings. Therefore, ID-based scheme without pairing is of great interest in the field of cryptography. Up to now,there still remains a challenge to construct ID-based signature scheme from quadratic residues. Thus, we aim to meet this challenge by proposing a concrete scheme. In this paper, we first introduce the technique of how to calculate a 2lth root of a quadratic residue, and then give a concrete ID-based signature scheme using such technique.We also prove that our scheme is chosen message and ID secure in the random oracle model, assuming the hardness of factoring.

  16. XML-Based SHINE Knowledge Base Interchange Language

    Science.gov (United States)

    James, Mark; Mackey, Ryan; Tikidjian, Raffi

    2008-01-01

    The SHINE Knowledge Base Interchange Language software has been designed to more efficiently send new knowledge bases to spacecraft that have been embedded with the Spacecraft Health Inference Engine (SHINE) tool. The intention of the behavioral model is to capture most of the information generally associated with a spacecraft functional model, while specifically addressing the needs of execution within SHINE and Livingstone. As such, it has some constructs that are based on one or the other.

  17. Evidence-based dentistry.

    Science.gov (United States)

    Chambers, David W

    2010-01-01

    Both panegyric and criticism of evidence-based dentistry tend to be clumsy because the concept is poorly defined. This analysis identifies several contributions to the profession that have been made under the EBD banner. Although the concept of clinicians integrating clinical epidemiology, the wisdom of their practices, and patients' values is powerful, its implementation has been distorted by a too heavy emphasis of computerized searches for research findings that meet the standards of academics. Although EBD advocates enjoy sharing anecdotal accounts of mistakes others have made, faulting others is not proof that one's own position is correct. There is no systematic, high-quality evidence that EBD is effective. The metaphor of a three-legged stool (evidence, experience, values, and integration) is used as an organizing principle. "Best evidence" has become a preoccupation among EBD enthusiasts. That overlong but thinly developed leg of the stool is critiqued from the perspectives of the criteria for evidence, the difference between internal and external validity, the relationship between evidence and decision making, the ambiguous meaning of "best," and the role of reasonable doubt. The strongest leg of the stool is clinical experience. Although bias exists in all observations (including searches for evidence), there are simple procedures that can be employed in practice to increase useful and objective evidence there, and there are dangers in delegating policy regarding allowable treatments to external groups. Patient and practitioner values are the shortest leg of the stool. As they are so little recognized, their integration in EBD is problematic and ethical tensions exist where paternalism privileges science over patient's self-determined best interests. Four potential approaches to integration are suggested, recognizing that there is virtually no literature on how the "seat" of the three-legged stool works or should work. It is likely that most dentists

  18. Game-based versus traditional case-based learning

    Science.gov (United States)

    Telner, Deanna; Bujas-Bobanovic, Maja; Chan, David; Chester, Bob; Marlow, Bernard; Meuser, James; Rothman, Arthur; Harvey, Bart

    2010-01-01

    ABSTRACT OBJECTIVE To evaluate family physicians’ enjoyment of and knowledge gained from game-based learning, compared with traditional case-based learning, in a continuing medical education (CME) event on stroke prevention and management. DESIGN An equivalence trial to determine if game-based learning was as effective as case-based learning in terms of attained knowledge levels. Game questions and small group cases were developed. Participants were randomized to either a game-based or a case-based group and took part in the event. SETTING Ontario provincial family medicine conference. PARTICIPANTS Thirty-two family physicians and 3 senior family medicine residents attending the conference. INTERVENTION Participation in either a game-based or a case-based CME learning group. MAIN OUTCOME MEASURES Scores on 40-item immediate and 3-month posttests of knowledge and a satisfaction survey. RESULTS Results from knowledge testing immediately after the event and 3 months later showed no significant difference in scoring between groups. Participants in the game-based group reported higher levels of satisfaction with the learning experience. CONCLUSION Games provide a novel way of organizing CME events. They might provide more group interaction and discussion, as well as improve recruitment to CME events. They might also provide a forum for interdisciplinary CME. Using games in future CME events appears to be a promising approach to facilitate participant learning. PMID:20841574

  19. Remote Monitoring System for Communication Base Based on Short Message

    Directory of Open Access Journals (Sweden)

    Han Yu Fu

    2013-07-01

    Full Text Available This paper presents design and development of an automatic monitoring system of communication base which is an important means to realize modernization of mobile communication base station management. Firstly, this paper proposes the architecture of the monitoring system. The proposed system consists of mocrocontrollers, sensors, GSM module and MFRC500 etc. The value of parameters is measured in the system including terminal is studied and designed, including hardware design based on embedded system and software design. Finally, communication module is discussed. The monitoring system which is designed  based on GSM SMS(short message service can improve the integrity, reliability, flexibility and intellectuality of monitoring system.

  20. Computer-based and web-based radiation safety training

    Energy Technology Data Exchange (ETDEWEB)

    Owen, C., LLNL

    1998-03-01

    The traditional approach to delivering radiation safety training has been to provide a stand-up lecture of the topic, with the possible aid of video, and to repeat the same material periodically. New approaches to meeting training requirements are needed to address the advent of flexible work hours and telecommuting, and to better accommodate individuals learning at their own pace. Computer- based and web-based radiation safety training can provide this alternative. Computer-based and web- based training is an interactive form of learning that the student controls, resulting in enhanced and focused learning at a time most often chosen by the student.

  1. Acids and bases solvent effects on acid-base strenght

    CERN Document Server

    Cox, Brian G

    2013-01-01

    Acids and bases are ubiquitous in chemistry. Our understanding of them, however, is dominated by their behaviour in water. Transfer to non-aqueous solvents leads to profound changes in acid-base strengths and to the rates and equilibria of many processes: for example, synthetic reactions involving acids, bases and nucleophiles; isolation of pharmaceutical actives through salt formation; formation of zwitter- ions in amino acids; and chromatographic separation of substrates. This book seeks to enhance our understanding of acids and bases by reviewing and analysing their behaviour in non-aqueous solvents. The behaviour is related where possible to that in water, but correlations and contrasts between solvents are also presented.

  2. Quantum Standard Teleportation Based on the Generic Measurement Bases

    Institute of Scientific and Technical Information of China (English)

    HAOSan-Ru; HOUBo-Yu; XIXiao-Qiang; YUERui-Hong

    2003-01-01

    We study the quantum standard teleportation based on the generic measurement bases. It is shown that the quantum standard teleportation does not depend on the explicit expression of the measurement bases. We have given the correspondence relation between the measurement performed by Alice and the unitary transformation performed by Bob. We also prove that the single particle unknown states and the two-particle unknown cat-like states can be exactly transmitted by means of the generic measurement bases and the correspondence unitary transformations.

  3. Quantum Standard Teleportation Based on the Generic Measurement Bases

    Institute of Scientific and Technical Information of China (English)

    HAO San-Ru; HOU Bo-Yu; XI Xiao-Qiang; YUE Rui-Hong

    2003-01-01

    We study the quantum standard teleportation based on the generic measurement bases. It is shown that the quantum standard teleportation does not depend on the explicit expression of the measurement bases. We have giventhe correspondence relation between the measurement performed by Alice and the unitary transformation performed byBob. We also prove that the single particle unknown states and the two-particle unknown cat-like states can be exactlytransmitted by means of the generic measurement bases and the correspondence unitary transformations.

  4. The knowledge base of journalism

    DEFF Research Database (Denmark)

    Svith, Flemming

    In this paper I propose the knowledge base as a fruitful way to apprehend journalism. With the claim that the majority of practice is anchored in knowledge – understood as 9 categories of rationales, forms and levels – this knowledge base appears as a contextual look at journalists’ knowledge......, and place. As an analytical framework, the knowledge base is limited to understand the practice of newspaper journalists, but, conversely, the knowledge base encompasses more general beginnings through the inclusion of overall structural relationships in the media and journalism and general theories...... on practice and knowledge. As the result of an abductive reasoning is a theory proposal, there is a need for more deductive approaches to test the validity of this knowledge base claim. It is thus relevant to investigate which rationales are included in the knowledge base of journalism, as the dimension does...

  5. Machine Learning Based Malware Detection

    Science.gov (United States)

    2015-05-18

    A TRIDENT SCHOLAR PROJECT REPORT NO. 440 Machine Learning Based Malware Detection by Midshipman 1/C Zane A. Markel, USN...public release and sale; its distribution is limited. U.S.N.A. --- Trident Scholar project report; no. 440 (2015) MACHINE LEARNING BASED MALWARE...COVERED (From - To) 4. TITLE AND SUBTITLE Machine Learning Based Malware Detection 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM

  6. Consortia based production of biochemicals

    DEFF Research Database (Denmark)

    Ingemann Jensen, Sheila; Sukumara, Sumesh; Özdemir, Emre;

    -based modelling, and state-of-the art metabolic engineering tools to develop a consortium of cells capable of efficient valorization of synthetic hemicellulosic hydrolysate. Stable co-existence and effective covalorization was achieved through niche-differentiation, auxotrophy, and adaptive evolution. In another...... study, stable consortia based fermentation was achieved through niche partitioning, syntrophy (auxotrophy combined with removal of inhibitory side product), and CRISPRi mediated gene silencing. The achieved results demonstrate that consortium based approaches for valorizing complex biomass and waste...

  7. Principles of models based engineering

    Energy Technology Data Exchange (ETDEWEB)

    Dolin, R.M.; Hefele, J.

    1996-11-01

    This report describes a Models Based Engineering (MBE) philosophy and implementation strategy that has been developed at Los Alamos National Laboratory`s Center for Advanced Engineering Technology. A major theme in this discussion is that models based engineering is an information management technology enabling the development of information driven engineering. Unlike other information management technologies, models based engineering encompasses the breadth of engineering information, from design intent through product definition to consumer application.

  8. Trace-Based Code Generation for Model-Based Testing

    NARCIS (Netherlands)

    Kanstrén, T.; Piel, E.; Gross, H.-G.

    2009-01-01

    Paper Submitted for review at the Eighth International Conference on Generative Programming and Component Engineering. Model-based testing can be a powerful means to generate test cases for the system under test. However, creating a useful model for model-based testing requires expertise in the (fo

  9. Web-based support systems

    CERN Document Server

    Yao, JingTao

    2010-01-01

    The emerging interdisciplinary study of Web-based support systems focuses on the theories, technologies and tools for the design and implementation of Web-based systems that support various human activities. This book presents the state-of-the-art in Web-based support systems (WSS). The research on WSS is multidisciplinary and focuses on supporting various human activities in different domains/fields based on computer science, information technology, and Web technology. The main goal is to take the opportunities of the Web, to meet the challenges of the Web, to extend the human physical limita

  10. On Pimsner-Popa bases

    Indian Academy of Sciences (India)

    Keshab Chandra Bakshi

    2017-02-01

    In this paper, we examine bases for finite index inclusion of ${\\rm II}_1$ factors and connected inclusion of finite dimensional $C^\\ast$-algebras. These bases behave nicely with respect to basic construction towers. As applications we have studied automorphisms of the hyperfinite ${\\rm II}_1$ factor $R$ which are ‘compatible with respect to the Jones’ tower of finite dimensional $C^\\ast$-algebras’. As a further application, in both cases we obtain a characterization, in terms of bases, of basic constructions. Finally we use these bases to describe the phenomenon of multistep basic constructions (in both the cases).

  11. Methods in Logic Based Control

    DEFF Research Database (Denmark)

    Christensen, Georg Kronborg

    1999-01-01

    Desing and theory of Logic Based Control systems.Boolean Algebra, Karnaugh Map, Quine McClusky's algorithm. Sequential control design. Logic Based Control Method, Cascade Control Method. Implementation techniques: relay, pneumatic, TTL/CMOS,PAL and PLC- and Soft_PLC implementation. PLC-design met......Desing and theory of Logic Based Control systems.Boolean Algebra, Karnaugh Map, Quine McClusky's algorithm. Sequential control design. Logic Based Control Method, Cascade Control Method. Implementation techniques: relay, pneumatic, TTL/CMOS,PAL and PLC- and Soft_PLC implementation. PLC...

  12. Capability-based computer systems

    CERN Document Server

    Levy, Henry M

    2014-01-01

    Capability-Based Computer Systems focuses on computer programs and their capabilities. The text first elaborates capability- and object-based system concepts, including capability-based systems, object-based approach, and summary. The book then describes early descriptor architectures and explains the Burroughs B5000, Rice University Computer, and Basic Language Machine. The text also focuses on early capability architectures. Dennis and Van Horn's Supervisor; CAL-TSS System; MIT PDP-1 Timesharing System; and Chicago Magic Number Machine are discussed. The book then describes Plessey System 25

  13. Evidence-Based Laboratory Medicine

    Institute of Scientific and Technical Information of China (English)

    Christopher P Price

    2004-01-01

    @@ Whilst there have been several definitions of Evidence-Based Medicine (EBM), the one given by David Sackett is probably the most accurate and well accepted; he stated that "evidence-based medicine is the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients"[1].

  14. Plasma-based accelerator structures

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, Carl B. [Univ. of California, Berkeley, CA (United States)

    1999-12-01

    Plasma-based accelerators have the ability to sustain extremely large accelerating gradients, with possible high-energy physics applications. This dissertation further develops the theory of plasma-based accelerators by addressing three topics: the performance of a hollow plasma channel as an accelerating structure, the generation of ultrashort electron bunches, and the propagation of laser pulses is underdense plasmas.

  15. Theory-Based Stakeholder Evaluation

    Science.gov (United States)

    Hansen, Morten Balle; Vedung, Evert

    2010-01-01

    This article introduces a new approach to program theory evaluation called theory-based stakeholder evaluation or the TSE model for short. Most theory-based approaches are program theory driven and some are stakeholder oriented as well. Practically, all of the latter fuse the program perceptions of the various stakeholder groups into one unitary…

  16. Dog Mathematics: Exploring Base-4

    Science.gov (United States)

    Kurz, Terri L.; Yanik, H. Bahadir; Lee, Mi Yeon

    2016-01-01

    Using a dog's paw as a basis for numerical representation, sixth grade students explored how to count and regroup using the dog's four digital pads. Teachers can connect these base-4 explorations to the conceptual meaning of place value and regrouping using base-10.

  17. Knowledge-Based Asynchronous Programming

    NARCIS (Netherlands)

    Haan, Hendrik Wietze de; Hesselink, Wim H.; Renardel de Lavalette, Gerard R.

    2004-01-01

    A knowledge-based program is a high-level description of the behaviour of agents in terms of knowledge that an agent must have before (s)he may perform an action. The definition of the semantics of knowledge-based programs is problematic, since it involves a vicious circle; the knowledge of an agent

  18. Eye-based head gestures

    DEFF Research Database (Denmark)

    Mardanbegi, Diako; Witzner Hansen, Dan; Pederson, Thomas

    2012-01-01

    A novel method for video-based head gesture recognition using eye information by an eye tracker has been proposed. The method uses a combination of gaze and eye movement to infer head gestures. Compared to other gesture-based methods a major advantage of the method is that the user keeps the gaze...

  19. Cloud-Based Data Storage

    Science.gov (United States)

    Waters, John K.

    2011-01-01

    The vulnerability and inefficiency of backing up data on-site is prompting school districts to switch to more secure, less troublesome cloud-based options. District auditors are pushing for a better way to back up their data than the on-site, tape-based system that had been used for years. About three years ago, Hendrick School District in…

  20. Team-Based Global Organizations

    DEFF Research Database (Denmark)

    Zander, Lena; Butler, Christina Lea; Mockaitis, Audra;

    2015-01-01

    Purpose-We propose team-based organizing as an alternative to more traditional forms of hierarchy-based organizing in global firms. Methodology/approach-Advancements in the study of global teams, leadership, process, and outcomes were organized into four themes: (1) openness toward linguistic and...

  1. GPP-Based Soft Base Station Designing and Optimization

    Institute of Scientific and Technical Information of China (English)

    Xiao-Feng Tao; Yan-Zhao Hou; Kai-Dong Wang; Hai-Yang He; Y.Jay Guo

    2013-01-01

    It is generally acknowledged that mobile communication base stations are composed of hardware components such as Field Programming Gate Array (FPGA),Digital Signal Processor (DSP),which promise reliable and fluent services for the mobile users.However,with the increasing demand for energy-efficiency,approaches of low power-consumption and high-flexibility are needed urgently.In this circumstance,General Purpose Processor (GPP) attracts people's attention for its low-cost and flexibility.Benefited from the development of modern GPP in multi-core,Single Instruction Multiple Data (SIMD) instructions,larger cache,etc.,GPPs are capable of performing high-density digital processing.In this paper,we compare several software-defined radio (SDR) prototypes and propose the general architecture of GPP-based soft base stations.Then,the schematic design of resource allocation and algorithm optimization in soft base station implementation are studied.As an application example,a prototype of GPP-based soft base station referring to the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) is realized and evaluated.To the best of our knowledge,it is the first Soft-LTE prototype ever reported.In the end,we evaluate the timing performance of the LTE soft base station and a packet loss ratio of less than 0.003 is obtained.

  2. Tag Based Audio Search Engine

    Directory of Open Access Journals (Sweden)

    Parameswaran Vellachu

    2012-03-01

    Full Text Available The volume of the music database is increasing day by day. Getting the required song as per the choice of the listener is a big challenge. Hence, it is really hard to manage this huge quantity, in terms of searching, filtering, through the music database. It is surprising to see that the audio and music industry still rely on very simplistic metadata to describe music files. However, while searching audio resource, an efficient "Tag Based Audio Search Engine" is necessary. The current research focuses on two aspects of the musical databases 1. Tag Based Semantic Annotation Generation using the tag based approach.2. An audio search engine, using which the user can retrieve the songs based on the users choice. The proposed method can be used to annotation and retrieve songs based on musical instruments used , mood of the song, theme of the song, singer, music director, artist, film director, instrument, genre or style and so on.

  3. Lignin-Based Thermoplastic Materials.

    Science.gov (United States)

    Wang, Chao; Kelley, Stephen S; Venditti, Richard A

    2016-04-21

    Lignin-based thermoplastic materials have attracted increasing interest as sustainable, cost-effective, and biodegradable alternatives for petroleum-based thermoplastics. As an amorphous thermoplastic material, lignin has a relatively high glass-transition temperature and also undergoes radical-induced self-condensation at high temperatures, which limits its thermal processability. Additionally, lignin-based materials are usually brittle and exhibit poor mechanical properties. To improve the thermoplasticity and mechanical properties of technical lignin, polymers or plasticizers are usually integrated with lignin by blending or chemical modification. This Review attempts to cover the reported approaches towards the development of lignin-based thermoplastic materials on the basis of published information. Approaches reviewed include plasticization, blending with miscible polymers, and chemical modifications by esterification, etherification, polymer grafting, and copolymerization. Those lignin-based thermoplastic materials are expected to show applications as engineering plastics, polymeric foams, thermoplastic elastomers, and carbon-fiber precursors.

  4. Schiff Bases: A Versatile Pharmacophore

    Directory of Open Access Journals (Sweden)

    Anu Kajal

    2013-01-01

    Full Text Available Schiff bases are condensation products of primary amines with carbonyl compounds gaining importance day by day in present scenario. Schiff bases are the compounds carrying imine or azomethine (–C=N– functional group and are found to be a versatile pharmacophore for design and development of various bioactive lead compounds. Schiff bases exhibit useful biological activities such anti-inflammatory, analgesic, antimicrobial, anticonvulsant, antitubercular, anticancer, antioxidant, anthelmintic, antiglycation, and antidepressant activities. Schiff bases are also used as catalysts, pigments and dyes, intermediates in organic synthesis, polymer stabilizers, and corrosion inhibitors. The present review summarizes information on the diverse biological activities and also highlights the recently synthesized numerous Schiff bases as potential bioactive core.

  5. Team-based global organizations

    DEFF Research Database (Denmark)

    Zander, Lena; Butler, Christina; Mockaitis, Audra

    2015-01-01

    This chapter draws on a panel discussion of the future of global organizing as a team-based organization at EIBA 2014 in Uppsala, Sweden. We began by discussing contemporary developments of hybrid forms of hierarchy and teams-based organizing, but we venture to propose that as organizations become...... characterized by decreased importance of hierarchal structures, more fluidity across borders, even a possible dissolution of firm boundaries, we move towards team-based organizing as an alternative to more traditional forms of hierarchical-based organizing in global firms. To provide input for a discussion...... of challenges and opportunities of future global organizing as being team-based, we presented new advancements in the study of global teams, leadership, process and outcomes divided into four themes. Two specifically address processes in global teams: 1) the benefits of openness towards linguistic and value...

  6. Content-Based Image Retrial Based on Hadoop

    Directory of Open Access Journals (Sweden)

    DongSheng Yin

    2013-01-01

    Full Text Available Generally, time complexity of algorithms for content-based image retrial is extremely high. In order to retrieve images on large-scale databases efficiently, a new way for retrieving based on Hadoop distributed framework is proposed. Firstly, a database of images features is built by using Speeded Up Robust Features algorithm and Locality-Sensitive Hashing and then perform the search on Hadoop platform in a parallel way specially designed. Considerable experimental results show that it is able to retrieve images based on content on large-scale cluster and image sets effectively.

  7. Image based Monument Recognition using Graph based Visual Saliency

    DEFF Research Database (Denmark)

    Kalliatakis, Grigorios; Triantafyllidis, Georgios

    2013-01-01

    This article presents an image-based application aiming at simple image classification of well-known monuments in the area of Heraklion, Crete, Greece. This classification takes place by utilizing Graph Based Visual Saliency (GBVS) and employing Scale Invariant Feature Transform (SIFT) or Speeded......, the images have been previously processed according to the Graph Based Visual Saliency model in order to keep either SIFT or SURF features corresponding to the actual monuments while the background “noise” is minimized. The application is then able to classify these images, helping the user to better...

  8. Comparative Study of Triangulation based and Feature based Image Morphing

    Directory of Open Access Journals (Sweden)

    Ms. Bhumika G. Bhatt

    2012-01-01

    Full Text Available Image Morphing is one of the most powerful Digital Image processing technique, which is used to enhancemany multimedia projects, presentations, education and computer based training. It is also used inmedical imaging field to recover features not visible in images by establishing correspondence of featuresamong successive pair of scanned images. This paper discuss what morphing is and implementation ofTriangulation based morphing Technique and Feature based Image Morphing. IT analyze both morphingtechniques in terms of different attributes such as computational complexity, Visual quality of morphobtained and complexity involved in selection of features.

  9. Value-based metrics and Internet-based enterprises

    Science.gov (United States)

    Gupta, Krishan M.

    2001-10-01

    Within the last few years, a host of value-based metrics like EVA, MVA, TBR, CFORI, and TSR have evolved. This paper attempts to analyze the validity and applicability of EVA and Balanced Scorecard for Internet based organizations. Despite the collapse of the dot-com model, the firms engaged in e- commerce continue to struggle to find new ways to account for customer-base, technology, employees, knowledge, etc, as part of the value of the firm. While some metrics, like the Balance Scorecard are geared towards internal use, others like EVA are for external use. Value-based metrics are used for performing internal audits as well as comparing firms against one another; and can also be effectively utilized by individuals outside the firm looking to determine if the firm is creating value for its stakeholders.

  10. G -Frames, g -orthonormal bases and g -Riesz bases

    Directory of Open Access Journals (Sweden)

    Seyedeh Sara Karimizad

    2014-05-01

    Full Text Available G-Frames in Hilbert spaces are a redundant set of operators which yield a repre-sentation for each vector in the space. In this paper we investigate the connection betweeng-frames, g-orthonormal bases and g-Riesz bases. We show that a family of bounded opera-tors is a g-Bessel sequences if and only if the Gram matrix associated to its denes a bounded operator

  11. Common-image gathers in the offset domain from reverse-time migration

    KAUST Repository

    Zhan, Ge

    2014-04-01

    Kirchhoff migration is flexible to output common-image gathers (CIGs) in the offset domain by imaging data with different offsets separately. These CIGs supply important information for velocity model updates and amplitude-variation-with-offset (AVO) analysis. Reverse-time migration (RTM) offers more insights into complex geology than Kirchhoff migration by accurately describing wave propagation using the two-way wave equation. But, it has difficulty to produce offset domain CIGs like Kirchhoff migration. In this paper, we develop a method for obtaining offset domain CIGs from RTM. The method first computes the RTM operator of an offset gather, followed by a dot product of the operator and the offset data to form a common-offset RTM image. The offset domain CIGs are then achieved after separately migrating data with different offsets. We generate offset domain CIGs on both the Marmousi synthetic data and 2D Gulf of Mexico real data using this approach. © 2014.

  12. nanoparticles

    Science.gov (United States)

    Zhao, Yu; Li, Hui; Liu, Xu-Jun; Guan, Lei-Lei; Li, Yan-Li; Sun, Jian; Ying, Zhi-Feng; Wu, Jia-Da; Xu, Ning

    2014-06-01

    Evenly separated crystalline CuIn0.8Ga0.2Se2 (CIGS) nanoparticles are deposited on ITO-glass substrate by pulsed laser deposition. Such CIGS layers are introduced between conjugated polymer layers and ITO-glass substrates for enhancing light absorbance of polymer solar cells. The P3HT:PCBM absorbance between 300 and 650 nm is enhanced obviously due to the introduction of CIGS nanoparticles. The current density-voltage curves of a P3HT:PCBM/CIGS solar cell demonstrate that the short-circuit current density is improved from 0.77 to 1.20 mA/cm2. The photoluminescence spectra show that the excitons in the polymer are obviously quenched, suggesting that the charge transfer between the P3HT:PCBM and CIGS occurred. The results reveal that the CIGS nanoparticles may exhibit the localized surface plasmon resonance effect just as metallic nanostructures.

  13. Base isolation system and verificational experiment of base isolated building

    Energy Technology Data Exchange (ETDEWEB)

    Takeuchi, Mikio; Harada, Osamu; Aoyagi, Sakae; Matsuda, Taiji

    1987-05-15

    With the objective of rationalization of the earthquake resistant design and the economical design based thereupon, many base isolation systems have been proposed and its research, development and application have been made in recent years. In order to disseminate the system, it is necessary to accumulate the data obtained from vibration tests and earthquake observations and verify the reliability of the system. From this viewpoint, the Central Research Institute of Electric power Industry and Okumura Corporation did the following experiments with a base isolated building as the object: 1) static power application experiments, 2) shaking experiments, 3) free vibration experiments, 4) regular slight vibration observations and 5) earthquake response observations (continuing). This article reports the outline of the base isolation system and the base isolated building concerned as well as the results of the verification experiments 1) through 3) above. From the results of these verification experiments, the basic vibration characteristics of the base isolation system consisting of laminated rubber and plastic damper were revealed and its functions were able to be verified. Especially during the free vibration experiments, the initial displacement even up to a maximum of 10cm was applied to the portion between the foundation and the structure and this displacement corresponds to the responded amplitude in case of the earthquake of seismic intensity of the 6th degree. It is planned to continue the verification further. (18 figs, 3 tabs, 3 photos, 6 refs)

  14. Formal Component-Based Semantics

    CERN Document Server

    Madlener, Ken; van Eekelen, Marko; 10.4204/EPTCS.62.2

    2011-01-01

    One of the proposed solutions for improving the scalability of semantics of programming languages is Component-Based Semantics, introduced by Peter D. Mosses. It is expected that this framework can also be used effectively for modular meta theoretic reasoning. This paper presents a formalization of Component-Based Semantics in the theorem prover Coq. It is based on Modular SOS, a variant of SOS, and makes essential use of dependent types, while profiting from type classes. This formalization constitutes a contribution towards modular meta theoretic formalizations in theorem provers. As a small example, a modular proof of determinism of a mini-language is developed.

  15. Solar based hydrogen production systems

    CERN Document Server

    Dincer, Ibrahim

    2013-01-01

    This book provides a comprehensive analysis of various solar based hydrogen production systems. The book covers first-law (energy based) and second-law (exergy based) efficiencies and provides a comprehensive understanding of their implications. It will help minimize the widespread misuse of efficiencies among students and researchers in energy field by using an intuitive and unified approach for defining efficiencies. The book gives a clear understanding of the sustainability and environmental impact analysis of the above systems. The book will be particularly useful for a clear understanding

  16. Context based multimedia information retrieval

    DEFF Research Database (Denmark)

    Mølgaard, Lasse Lohilahti

    with the help of contextual knowledge. Our approach to model the context of multimedia is based on unsupervised methods to automatically extract meaning. We investigate two paths of context modelling. The first part extracts context from the primary media, in this case broadcast news speech, by extracting...... through an approximation based on non-negative matrix factorisation NMF. The second part of the work tries to infer the contextual meaning of music based on extra-musical knowledge, in our case gathered from Wikipedia. The semantic relations between artists are inferred using linking structure...

  17. Home-based Healthcare Technology

    DEFF Research Database (Denmark)

    Verdezoto, Nervo

    Sustaining daily, unsupervised healthcare activities in non-clinical settings such as the private home can challenge, among others, older adults. To support such unsupervised care activities, an increasingly number of reminders and monitoring systems are being designed. However, most...... of these systems target a specific treatment or condition and might not be sufficient to support the care management work at home. Based on a case study approach, my research investigates home-based healthcare practices and how they can inform future design of home-based healthcare technology that better account...... for the home setting and people’s everyday activities....

  18. Seeing graphene-based sheets

    Directory of Open Access Journals (Sweden)

    Jaemyung Kim

    2010-03-01

    Full Text Available Graphene-based sheets such as graphene, graphene oxide and reduced graphene oxide have stimulated great interest due to their promising electronic, mechanical and thermal properties. Microscopy imaging is indispensable for characterizing these single atomic layers, and oftentimes is the first measure of sample quality. This review provides an overview of current imaging techniques for graphene-based sheets and highlights a recently developed fluorescence quenching microscopy technique that allows high-throughput, high-contrast imaging of graphene-based sheets on arbitrary substrate and even in solution.

  19. Mitochondrial base excision repair assays

    DEFF Research Database (Denmark)

    Maynard, Scott; de Souza-Pinto, Nadja C; Scheibye-Knudsen, Morten

    2010-01-01

    The main source of mitochondrial DNA (mtDNA) damage is reactive oxygen species (ROS) generated during normal cellular metabolism. The main mtDNA lesions generated by ROS are base modifications, such as the ubiquitous 8-oxoguanine (8-oxoG) lesion; however, base loss and strand breaks may also occur....... Many human diseases are associated with mtDNA mutations and thus maintaining mtDNA integrity is critical. All of these lesions are repaired primarily by the base excision repair (BER) pathway. It is now known that mammalian mitochondria have BER, which, similarly to nuclear BER, is catalyzed by DNA...

  20. Agent Based Individual Traffic Guidance

    DEFF Research Database (Denmark)

    Wanscher, Jørgen

    This thesis investigates the possibilities in applying Operations Research (OR) to autonomous vehicular traffic. The explicit difference to most other research today is that we presume that an agent is present in every vehicle - hence Agent Based Individual Traffic guidance (ABIT). The next...... evolutionary step for the in-vehicle route planners is the introduction of two-way communication. We presume that the agent is capable of exactly this. Based on this presumption we discuss the possibilities and define a taxonomy and use this to discuss the ABIT system. Based on a set of scenarios we conclude...