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Sample records for zinc telluride solar

  1. Development of planar waveguides in zinc telluride

    International Nuclear Information System (INIS)

    Valette, Serge

    1977-02-01

    Zinc telluride (ZnTe) is one of the most attractive semi-conductors for monolithic integrated optics. In this study, the general characteristics of the planar optical waveguides achieved by implantation of light ions in ZnTe are investigated. Different aspects of prism-coupling and coherent light guiding have been taken up theoretically and experimentally. Some assumptions about the physical origin of these structures are discussed in order to explain all these results and the weak losses which have been measured. [fr

  2. Properties of Nitrogen-Doped Zinc Telluride Films for Back Contact to Cadmium Telluride Photovoltaics

    Science.gov (United States)

    Shimpi, Tushar M.; Drayton, Jennifer; Swanson, Drew E.; Sampath, Walajabad S.

    2017-08-01

    Zinc telluride (ZnTe) films have been deposited onto uncoated glass superstrates by reactive radiofrequency (RF) sputtering with different amounts of nitrogen introduced into the process gas, and the structural and electronic transport properties of the resulting nitrogen-doped ZnTe (ZnTe:N) films characterized. Based on transmission and x-ray diffraction measurements, it was observed that the crystalline quality of the ZnTe:N films decreased with increasing nitrogen in the deposition process. The bulk carrier concentration of the ZnTe:N films determined from Hall-effect measurements showed a slight decrease at 4% nitrogen flow rate. The effect of ZnTe:N films as back contact to cadmium telluride (CdTe) solar cells was also investigated. ZnTe:N films were deposited before or after CdCl2 passivation on CdTe/CdS samples. Small-area devices were characterized for their electronic properties. Glancing-angle x-ray diffraction measurements and energy-dispersive spectroscopy analysis confirmed substantial loss of zinc from the samples where CdCl2 passivation was carried out after ZnTe:N film deposition.

  3. Gamma-ray peak shapes from cadmium zinc telluride detectors

    Energy Technology Data Exchange (ETDEWEB)

    Namboodiri, M.N.; Lavietes, A.D.; McQuaid, J.H.

    1996-09-01

    We report the results of a study of the peak shapes in the gamma spectra measured using several 5 x 5 x 5 mm{sup 3} cadmium zinc telluride (CZT) detectors. A simple parameterization involving a Gaussian and an exponential low energy tail describes the peak shapes sell. We present the variation of the parameters with gamma energy. This type of information is very useful in the analysis of complex gamma spectra consisting of many peaks.

  4. Study on thermal annealing of cadmium zinc telluride (CZT) crystals

    International Nuclear Information System (INIS)

    Yang, G.; Bolotnikov, A.E.; Fochuk, P.M.; Camarda, G.S.; Cui, Y.; Hossain, A.; Kim, K.; Horace, J.; McCall, B.; Gul, R.; Xu, L.; Kopach, O.V.; James, R.B.

    2010-01-01

    Cadmium Zinc Telluride (CZT) has attracted increasing interest with its promising potential as a room-temperature nuclear-radiation-detector material. However, different defects in CZT crystals, especially Te inclusions and dislocations, can degrade the performance of CZT detectors. Post-growth annealing is a good approach potentially to eliminate the deleterious influence of these defects. At Brookhaven National Laboratory (BNL), we built up different facilities for investigating post-growth annealing of CZT. Here, we report our latest experimental results. Cd-vapor annealing reduces the density of Te inclusions, while large temperature gradient promotes the migration of small-size Te inclusions. Simultaneously, the annealing lowers the density of dislocations. However, only-Cd-vapor annealing decreases the resistivity, possibly reflecting the introduction of extra Cd in the lattice. Subsequent Te-vapor annealing is needed to ensure the recovery of the resistivity after removing the Te inclusions.

  5. Telluride School, Telluride, Colorado solar-energy-system performance evaluation, February 1982-April 1982

    Energy Technology Data Exchange (ETDEWEB)

    Welch, K.M.

    1982-01-01

    The Telluride School solar site is an elementary/junior-senior high school in Colorado with a passive/active hybrid solar energy system designed to supply 40% of the heating load. It is equipped with a 1428 square foot, double glazed Trombe wall, a 1392 square foot greenhouse with collection tube, and an auxiliary oil-fired boiler. Monthly performance data are tabulated for the overall system and for the Trombe wall, greenhouse, and greenhouse storage. System operation is illustrated by graphs of typical Trombe wall insolation and temperatures and typical greenhouse insolation and temperatures. (LEW)

  6. A cadmium-zinc-telluride crystal array spectrometer

    International Nuclear Information System (INIS)

    McHugh, H. R.; Quam, W.; DeVore, T.; Vogle, R.; Weslowski, J.

    2003-01-01

    This paper describes a gamma detector employing an array of eight cadmium-zinc-telluride (CZT) crystals configured as a high resolution gamma ray spectrometer. This detector is part of a more complex instrument that identifies the isotope,displays this information, and records the gamma spectrum. Various alarms and other operator features are incorporated in this battery operated rugged instrument. The CZT detector is the key component of this instrument and will be described in detail in this paper. We have made extensive spectral measurements of the usual laboratory gamma sources, common medical isotopes, and various Special Nuclear Materials (SNM) with this detector. Some of these data will be presented as spectra. We will also present energy resolution and detection efficiency for the basic 8-crystal array. Additional data will also be presented for a 32-crystal array. The basic 8-crystal array development was completed two years ago, and the system electronic design has been imp roved recently. This has resulted in significantly improved noise performance. We expect to have a much smaller detector package, using 8 crystals, in a few months. This package will use flip-chip packaging to reduce the electronics physical size by a factor of 5

  7. Preliminary uranium enrichment analysis results using cadmium zinc telluride detectors

    International Nuclear Information System (INIS)

    Lavietes, A.D.; McQuaid, J.H.; Paulus, T.J.

    1995-01-01

    Lawrence Livermore National Laboratory (LLNL) and EG ampersand G ORTEC have jointly developed a portable ambient-temperature detection system that can be used in a number of application scenarios. The detection system uses a planar cadmium zinc telluride (CZT) detector with custom-designed detector support electronics developed at LLNL and is based on the recently released MicroNOMAD multichannel analyzer (MCA) produced by ORTEC. Spectral analysis is performed using software developed at LLNL that was originally designed for use with high-purity germanium (HPGe) detector systems. In one application, the CZT detection system determines uranium enrichments ranging from less than 3% to over 75% to within accuracies of 20%. The analysis was performed using sample sizes of 200 g or larger and acquisition times of 30 min. The authors have demonstrated the capabilities of this system by analyzing the spectra gathered by the CZT detection system from uranium sources of several enrichments. These experiments demonstrate that current CZT detectors can, in some cases, approach performance criteria that were previously the exclusive domain of larger HPGe detector systems

  8. Cadmium zinc telluride as a mid-infrared variable retarder

    Science.gov (United States)

    FitzGerald, William; Taherion, Saeid; Kumar, F. Joseph; Giles, David; Hore, Dennis

    2018-04-01

    The electro-optic behavior of cadmium zinc telluride is examined in the mid-infrared region between 3 and 11 μm, for applied DC field strengths of up to 106 V/m. The measurements performed here include full characterization of the polarization state of the transmitted light by means of the Stokes vector. We demonstrate the suitability of this material for DC variable retarder applications such as those achieved by quarter- or half-wave retardation. A comparison of two different metallic coatings for electrodes, gold and indium, reveals important differences in performance that are attributed to the homogeneity of the field through the bulk of the crystal. We illustrate that, in the case of both metals, the same electro-optic coefficients are measured, but regions of higher and lower retardation result in significant depolarization in the case of gold. Such depolarization may adversely affect the contrast ratio in a light valve, or increase the voltage necessary for the operation of an arbitrary polarization state generator.

  9. Process for obtaining oxygen doped zinc telluride monocrystals and scintillator crystals obtained by this process

    International Nuclear Information System (INIS)

    Schneider, Maurice; Moreau, Roland; D'Haenen, J.-P.; Merenda, Pierre.

    1976-01-01

    A process is described for obtaining oxygen doped zinc telluride monocrystals, for use as scintillator crystals for ionising radiation detectors. The following operations are carried out in succession: one or several zinc telluride crystals are introduced into a silica ampoule together with a ternary mixture of zinc tellurium and oxygen, as an oxide or hydroxide of these elements; the ampoule is pumped down to a high vacuum and sealed; the sealed ampoule containing the mixture and monocrystals is placed in a kiln and brought to a uniform temperature sufficient to make the mixture three-phased, depending on its composition; the zinc telluride crystalline compound remains solid; the ampoule is then tempered to bring it quickly back to ambient temperature [fr

  10. Characterization of large cadmium zinc telluride crystals grown by traveling heater method

    DEFF Research Database (Denmark)

    Chen, H.; Awadalla, S.A.; Iniewski, K.

    2008-01-01

    The focus of this paper is to evaluate thick, 20 X 20 X 10 and 10 X 10 X 10 mm(3), cadmium zinc telluride (CZT), Cd0.9Zn0.1Te, crystals grown using the traveling heater method (THIM). The phenomenal spectral performance and small size and low concentration of Te inclusions/precipitates of these c......The focus of this paper is to evaluate thick, 20 X 20 X 10 and 10 X 10 X 10 mm(3), cadmium zinc telluride (CZT), Cd0.9Zn0.1Te, crystals grown using the traveling heater method (THIM). The phenomenal spectral performance and small size and low concentration of Te inclusions...

  11. Formation of solid solutions on the boundary of zinc oxidezinc telluride heterojunction

    International Nuclear Information System (INIS)

    Tsurkan, A.E.; Buzhor, L.V.

    1987-01-01

    Distribution of ZnO x Te 1-x alloy composition on the interface of zinc oxide-zinc telluride heterojunction depending on the production conditions is investigated. A regularity in the formation of an extended area with constant alloy composition is detected. The regularity is explained by the fact that electric Peltier field conditioned by contact of two heterogeneous semiconductors participates in the solid solution formation process. Peltier field levels off the composition at the end length section. So, a possibility of creating a section with the assigned minor thickness alloy constant composition controlled in the interface of heterojunction occurs

  12. Tiny optical fiber temperature sensor based on temperature-dependent refractive index of zinc telluride film

    Science.gov (United States)

    Bian, Qiang; Song, Zhangqi; Song, Dongyu; Zhang, Xueliang; Li, Bingsheng; Yu, Yang; Chen, Yuzhong

    2018-03-01

    The temperature-dependent refractive index of zinc telluride film can be used to develop a tiny, low cost and film-coated optical fiber temperature sensor. Pulse reference-based compensation technique is used to largely reduce the background noise which makes it possible to detect the minor reflectivity change of the film in different temperatures. The temperature sensitivity is 0.0034dB/° and the background noise is measured to be 0.0005dB, so the resolution can achieve 0.2°.

  13. Spatial mapping of cadmium zinc telluride materials properties and electrical response to improve device yield and performance

    CERN Document Server

    Van Scyoc, J M; Yoon, H; Gilbert, T S; Hilton, N R; Lund, J C; James, R B

    1999-01-01

    Cadmium zinc telluride has experienced tremendous growth in its application to various radiation sensing problems over the last five years. However, there are still issues with yield, particularly of the large volume devices needed for imaging and sensitivity-critical applications. Inhomogeneities of various types and on various length scales currently prevent the fabrication of large devices of high spectral performance. This paper discusses the development of a set of characterization tools for quantifying these inhomogeneities, in order to develop improvement strategies to achieve the desired cadmium zinc telluride crystals for detector fabrication.

  14. Processing and Characterization of Thin Cadmium Telluride Solar Cells

    Science.gov (United States)

    Wojtowicz, Anna

    Cadmium telluride (CdTe) has the highest theoretical limit to conversion efficiency of single-junction photovoltaic (PV) technologies today. However, despite a maximum theoretical open-circuit voltage of 1.20 V, record devices have historically had voltages pinned around only 900 mV. Voltage losses due to high recombination rates remains to be the most complex hurdle to CdTe technology today, and the subject of on-going research in the physics PV group at Colorado State University. In this work, an ultrathin CdTe device architecture is proposed in an effort to reduce bulk recombination and boost voltages. By thinning the CdTe layer, a device's internal electric field extends fully towards the back contact. This quickly separates electrons-hole pairs throughout the bulk of the device and reduces overall recombination. Despite this advantage, very thin CdTe layers also present a unique set of optical and electrical challenges which result in performance losses not as prevalent in thicker devices. When fabricating CdTe solar cells, post-deposition treatments applied to the absorber layer are a critical step for achieving high efficiency devices. Exposure of the polycrystalline CdTe film to a chlorine species encourages the passivation of dangling bonds and larger grain formation, while copper-doping improves device uniformity and voltages. This work focuses on experiments conducted via close-space sublimation to optimize CdCl2 and CuCl treatments for thin CdTe solar cells. Sweeps of both exposure and anneal time were performed for both post-deposition treatments on CdTe devices with 1.0 mum absorber layers. The results demonstrate that thin CdTe devices require substantially less post-deposition processing than standard thicker devices as expected. Additionally, the effects of CdTe growth temperature on thin devices is briefly investigated. The results suggest that higher growth temperatures lead to both electrical and stoichiometric changes in CdTe closely associated

  15. Charge sharing and charge loss in a cadmium-zinc-telluride fine-pixel detector array

    International Nuclear Information System (INIS)

    Gaskin, J.A.; Sharma, D.P.; Ramsey, B.D.

    2003-01-01

    Because of its high atomic number, room temperature operation, low noise, and high spatial resolution a cadmium-zinc-telluride multi-pixel detector is ideal for hard X-ray astrophysical observation. As part of on-going research at MSFC to develop multi-pixel CdZnTe detectors for this purpose, we have measured charge sharing and charge loss for a 4x4 (750 μm pitch), 1 mm thick pixel array and modeled these results using a Monte-Carlo simulation. This model was then used to predict the amount of charge sharing for a much finer pixel array (with a 300 μm pitch). Future work will enable us to compare the simulated results for the finer array to measured values

  16. Low-cost cadmium zinc telluride radiation detectors based on electron-transport-only designs

    International Nuclear Information System (INIS)

    Brunett, B.A.; Lund, J.C.; Van Scyoc, J.M.; Hilton, N.R.; Lee, E.Y.; James, R.B.

    1999-01-01

    The goal of this project was to utilize a novel device design to build a compact, high resolution, room temperature operated semiconductor gamma ray sensor. This sensor was constructed from a cadmium zinc telluride (CZT) crystal. It was able to both detect total radiation intensity and perform spectroscopy on the detected radiation. CZT detectors produced today have excellent electron charge carrier collection, but suffer from poor hole collection. For conventional gamma-ray spectrometers, both the electrons and holes must be collected with high efficiency to preserve energy resolution. The requirement to collect the hole carriers, which have relatively low lifetimes, limits the efficiency and performance of existing experimental devices. By implementing novel device designs such that the devices rely only on the electron signal for energy information, the sensitivity of the sensors for detecting radiation can be increased substantially. In this report the authors describe a project to develop a new type of electron-only CZT detector. They report on their successful efforts to design, implement and test these new radiation detectors. In addition to the design and construction of the sensors the authors also report, in considerable detail, on the electrical characteristics of the CZT crystals used to make their detectors

  17. Study of a high-resolution, 3-D positioning cadmium zinc telluride detector for PET

    Science.gov (United States)

    Gu, Y; Matteson, J L; Skelton, R T; Deal, A C; Stephan, E A; Duttweiler, F; Gasaway, T M; Levin, C S

    2011-01-01

    This paper investigates the performance of 1 mm resolution Cadmium Zinc Telluride (CZT) detectors for positron emission tomography (PET) capable of positioning the 3-D coordinates of individual 511 keV photon interactions. The detectors comprise 40 mm × 40 mm × 5 mm monolithic CZT crystals that employ a novel cross-strip readout with interspersed steering electrodes to obtain high spatial and energy resolution. The study found a single anode FWHM energy resolution of 3.06±0.39% at 511 keV throughout most the detector volume. Improved resolution is expected with properly shielded front-end electronics. Measurements made using a collimated beam established the efficacy of the steering electrodes in facilitating enhanced charge collection across anodes, as well as a spatial resolution of 0.44±0.07 mm in the direction orthogonal to the electrode planes. Finally, measurements based on coincidence electronic collimation yielded a point spread function with 0.78±0.10 mm FWHM, demonstrating 1 mm spatial resolution capability transverse to the anodes – as expected from the 1 mm anode pitch. These findings indicate that the CZT-based detector concept has excellent performance and shows great promise for a high-resolution PET system. PMID:21335649

  18. Study of a high-resolution, 3D positioning cadmium zinc telluride detector for PET.

    Science.gov (United States)

    Gu, Y; Matteson, J L; Skelton, R T; Deal, A C; Stephan, E A; Duttweiler, F; Gasaway, T M; Levin, C S

    2011-03-21

    This paper investigates the performance of 1 mm resolution cadmium zinc telluride (CZT) detectors for positron emission tomography (PET) capable of positioning the 3D coordinates of individual 511 keV photon interactions. The detectors comprise 40 mm × 40 mm × 5 mm monolithic CZT crystals that employ a novel cross-strip readout with interspersed steering electrodes to obtain high spatial and energy resolution. The study found a single anode FWHM energy resolution of 3.06 ± 0.39% at 511 keV throughout most of the detector volume. Improved resolution is expected with properly shielded front-end electronics. Measurements made using a collimated beam established the efficacy of the steering electrodes in facilitating enhanced charge collection across anodes, as well as a spatial resolution of 0.44 ± 0.07 mm in the direction orthogonal to the electrode planes. Finally, measurements based on coincidence electronic collimation yielded a point spread function with 0.78 ± 0.10 mm FWHM, demonstrating 1 mm spatial resolution capability transverse to the anodes-as expected from the 1 mm anode pitch. These findings indicate that the CZT-based detector concept has excellent performance and shows great promise for a high-resolution PET system.

  19. Cadmium-Zinc-Telluride photon detector for epithermal neutron spectroscopy--pulse height response characterisation

    International Nuclear Information System (INIS)

    Tardocchi, M.; Pietropaolo, A.; Andreani, C.; Bracco, A.; D'Angelo, A.; Gorini, G.; Imberti, S.; Senesi, R.; Rhodes, N.J.; Schooneveld, E.M.

    2004-01-01

    The Resonance Detector Spectrometer was recently revised for neutron spectroscopic studies in the eV energy region. In this technique one makes use of a photon detector to record the gamma emission from analyser foils used as neutron-gamma converters. The pulse-height response of a Cadmium-Zinc-Telluride photon detector to neutron capture emission from 238 U and 197 Au analyser foils was characterised in the neutron energy range 1-200 eV. The experiment was performed on the VESUVIO spectrometer at the ISIS neutron-pulsed source. A biparametric data acquisition, specifically developed for these measurements, allowed the simultaneous measurements of both the neutron time of flight and γ pulse-height spectra. Through the analysis of the γ pulse-height spectra the main components of the signal associated with resonant and non-resonant neutron absorption were identified. It was also shown that, in principle, energy discrimination can be used to improve the signal to background ratio of the neutron time-of-flight measurement

  20. Investigation of the Electronic Properties of Cadmium Zinc Telluride (CZT) Detectors using a Nuclear Microprobe

    International Nuclear Information System (INIS)

    BRUNETT, BRUCE A.; DOYLE, BARNEY L.; JAMES, RALPH B.; VIZKELETHY, GYORGY; WALSH, DAVID S.

    1999-01-01

    The electronic transport properties of Cadmium Zinc Telluride (CZT) determine the charge collection efficiency (i.e. the signal quality) of CZT detectors. These properties vary on both macroscopic and microscopic scale and depend on the presence of impurities and defects introduced during the crystal growth. Ion Beam Induced Charge Collection (IBICC) is a proven method to measure the charge collection efficiency. Using an ion microbeam, the charge collection efficiency can be mapped with submicron resolution, and the map of electronic properties (such as drift length) can be calculated from the measurement. A more sophisticated version of IBICC, the Time Resolved IBICC (TRIBICC) allows them to determine the mobility and the life time of the charge carriers by recording and analyzing the transient waveform of the detector signal. Furthermore, lateral IBICC and TRIBICC can provide information how the charge collection efficiency depends on the depth where the charge carriers are generated. This allows one to deduce information on the distribution of the electric field and transport properties of the charge carriers along the detector axis. IBICC and TRIBICC were used at the Sandia microbeam facility to image electronic properties of several CZT detectors. From the lateral TRIBICC measurement the electron and hole drift length profiles were calculated

  1. Scientific/Technical Report: Improvement in compensation and crystal growth of cadmium zinc telluride radiation detectors

    International Nuclear Information System (INIS)

    Kelvin G. Lynn; Kelly A. Jones

    2007-01-01

    Comparison of actual accomplishments with goals and objectives: (1) Growth of 12 ingots--Washington State University (WSU) more than met this goal for the project by growing 12 final ingots for the year. Nine of the twelve crystal growth ingots resolved gamma radiation at room temperature. The other three ingots where resistivity of ∼ 3 x 10 8 Ohm*cm for CG32a, CG36, and CG42 lower than expected, however none of these were tried with blocking contacts. All ingots were evaluated from tip to heel. In these three cases, the group III, dopant Aluminum (Al) was not detected to a level to compensate the Cd vacancies in the cadmium zinc telluride (CZT) thus the ingots were lower resistivity. The nine ingots that were successful radiation detectors averaged a bulk resistivity of 1.25 x 10 10 Ohm*cm and with a average μτ product for electrons of ∼ 2 x 10 -4 cm 2 /V with a 1/4 microsecond shaping time with samples ∼2 mm in thickness. (2) Attempt new compensations techniques--WSU also met this goal. Several doping schemes were attempted and investigated with various amounts of excess Tellurium added to the growth. The combination of Al and Erbium (Er) were first attempted for these ingots and subsequently CG34 was grown with Al, Er and Holmium. These compensation techniques produced radiation detectors and are currently under investigation. These growths were made with significant different doping levels to determine the affect of the dopants. CG43 was doped with Indium and Er. Indium was introduced instead of Al to determine if Indium is more soluble than Al for CZT and was less oxidized. This may decrease the amount of low resistivity ingots grown by doping with Indium instead of Al. (3) Grow large single crystals--Several changes in approach occurred in the crystal growth furnace. Steps were taken to maximize the crystal growth interface during growth by modifying liners, quartz, heat sinks, crucibles and various growth steps and temperature profiles. CG39 ingot

  2. Thermodynamics of post-growth annealing of cadmium zinc telluride nuclear radiation detectors

    Science.gov (United States)

    Adams, Aaron Lee

    Nuclear Radiation Detectors are used for detecting, tracking, and identifying radioactive materials which emit high-energy gamma and X-rays. The use of Cadmium Zinc Telluride (CdZnTe) detectors is particularly attractive because of the detector's ability to operate at room temperature and measure the energy spectra of gamma-ray sources with a high resolution, typically less than 1% at 662 keV. While CdZnTe detectors are acceptable imperfections in the crystals limit their full market potential. One of the major imperfections are Tellurium inclusions generated during the crystal growth process by the retrograde solubility of Tellurium and Tellurium-rich melt trapped at the growth interface. Tellurium inclusions trap charge carriers generated by gamma and X-ray photons and thus reduce the portion of generated charge carriers that reach the electrodes for collection and conversion into a readable signal which is representative of the ionizing radiation's energy and intensity. One approach in resolving this problem is post-growth annealing which has the potential of removing the Tellurium inclusions and associated impurities. The goal of this project is to use experimental techniques to study the thermodynamics of Tellurium inclusion migration in post-growth annealing of CdZnTe nuclear detectors with the temperature gradient zone migration (TGZM) technique. Systematic experiments will be carried out to provide adequate thermodynamic data that will inform the engineering community of the optimum annealing parameters. Additionally, multivariable correlations that involve the Tellurium diffusion coefficient, annealing parameters, and CdZnTe properties will be analyzed. The experimental approach will involve systematic annealing experiments (in Cd vapor overpressure) on different sizes of CdZnTe crystals at varying temperature gradients ranging from 0 to 60°C/mm (used to migrate the Tellurium inclusion to one side of the crystal), and at annealing temperatures ranging

  3. Growth of Bi doped cadmium zinc telluride single crystals by Bridgman oscillation method and its structural, optical, and electrical analyses

    International Nuclear Information System (INIS)

    Carcelen, V.; Rodriguez-Fernandez, J.; Dieguez, E.; Hidalgo, P.

    2010-01-01

    The II-VI compound semiconductor cadmium zinc telluride (CZT) is very useful for room temperature radiation detection applications. In the present research, we have successfully grown Bi doped CZT single crystals with two different zinc concentrations (8 and 14 at. %) by the Bridgman oscillation method, in which one experiment has been carried out with a platinum (Pt) tube as the ampoule support. Pt also acts as a cold finger and reduces the growth velocity and enhances crystalline perfection. The grown single crystals have been studied with different analysis methods. The stoichiometry was confirmed by energy dispersive by x-ray and inductively coupled plasma mass spectroscopy analyses and it was found there is no incorporation of impurities in the grown crystal. The presence of Cd and Te vacancies was determined by cathodoluminescence studies. Electrical properties were assessed by I-V analysis and indicated higher resistive value (8.53x10 8 Ω cm) for the crystal grown with higher zinc concentration (with Cd excess) compare to the other (3.71x10 5 Ω cm).

  4. Effect of Annealing on the Properties of Antimony Telluride Thin Films and Their Applications in CdTe Solar Cells

    Directory of Open Access Journals (Sweden)

    Zhouling Wang

    2014-01-01

    Full Text Available Antimony telluride alloy thin films were deposited at room temperature by using the vacuum coevaporation method. The films were annealed at different temperatures in N2 ambient, and then the compositional, structural, and electrical properties of antimony telluride thin films were characterized by X-ray fluorescence, X-ray diffraction, differential thermal analysis, and Hall measurements. The results indicate that single phase antimony telluride existed when the annealing temperature was higher than 488 K. All thin films exhibited p-type conductivity with high carrier concentrations. Cell performance was greatly improved when the antimony telluride thin films were used as the back contact layer for CdTe thin film solar cells. The dark current voltage and capacitance voltage measurements were performed to investigate the formation of the back contacts for the cells with or without Sb2Te3 buffer layers. CdTe solar cells with the buffer layers can reduce the series resistance and eliminate the reverse junction between CdTe and metal electrodes.

  5. Templated growth of cadmium zinc telluride (CZT) nanowires using pulsed-potentials in hot non-aqueous solution

    International Nuclear Information System (INIS)

    Gandhi, T.; Raja, K.S.; Misra, M.

    2006-01-01

    A single step non-aqueous electrodeposition of cadmium zinc telluride (CZT) nanowires on nanoporous TiO 2 substrate was investigated under pulsed-potential conditions. Propylene carbonate was used as the non-aqueous medium. Cyclic voltammogram studies were carried out to understand the growth mechanism of CZT. EDAX and XRD measurements indicated formation of a compound semiconductor with a stoichiometry of Cd 1-x Zn x Te, where x varied between 0.04 and 0.2. Variation of the pulsed-cathodic potentials could modulate the composition of the CZT. More negative cathodic potentials resulted in increased Zn content. The nanowires showed an electronic band gap of about 1.6 eV. Mott-Schottky analyses indicated p-type semiconductor properties of both as-deposited and annealed CZT materials. Increase in Zn content increased the charge carrier density. Annealing of the deposits resulted in lower charge carrier densities, in the order of 10 15 cm -3

  6. Comparison of Cadmium-Zinc-Telluride semiconductor and Yttrium-Aluminum-Perovskite scintillator as photon detectors for epithermal neutron spectroscopy

    International Nuclear Information System (INIS)

    Tardocchi, M.; Pietropaolo, A.; Andreani, C.; Gorini, G.; Imberti, S.; Perelli-Cippo, E.; Senesi, R.; Rhodes, N.; Schooneveld, E.M.

    2006-01-01

    The range of applications of epithermal neutron scattering experiments has been recently extended by the development of the Resonance Detector. In a Resonance Detector, resonant neutron absorption in an analyzer foil results in prompt emission of X- and γ-rays which are detected by a photon counter. Several combinations of analyzer foils and photon detectors have been studied and tested over the years and best results have been obtained with the combination of a natural uranium and (i) Cadmium-Zinc-Telluride (CZT) semiconductor (ii) Yttrium-Aluminum-Perovskite (YAP) scintillators. Here we compare the performance of the CZT semiconductor and YAP scintillator as Resonance Detector units. Two Resonance Detector prototypes made of natural uranium foil viewed by CZT and YAP were tested on the VESUVIO spectrometer at the ISIS spallation neutron source. The results show that both YAP and CZT can be used to detect epithermal neutrons in the energy range from 1 up to 66 eV. It was found that the signal-to-background ratio of the measurement can significantly be improved by raising the lower level discrimination threshold on the γ energy to about 600 keV. The advantages/disadvantages of the choice of a Resonance Detector based on YAP or CZT are discussed together with some potential applications

  7. Diagnostic performance of a novel cadmium-zinc-telluride gamma camera system assessed using fractional flow reserve.

    Science.gov (United States)

    Tanaka, Hirokazu; Chikamori, Taishiro; Tanaka, Nobuhiro; Hida, Satoshi; Igarashi, Yuko; Yamashita, Jun; Ogawa, Masashi; Shiba, Chie; Usui, Yasuhiro; Yamashina, Akira

    2014-01-01

    Although the novel cadmium-zinc-telluride (CZT) camera system provides excellent image quality, its diagnostic value using thallium-201 as assessed on coronary angiography (CAG) and fractional flow reserve (FFR) has not been validated. METHODS AND RESULTS: To evaluate the diagnostic accuracy of the CZT ultrafast camera system (Discovery NM 530c), 95 patients underwent stress thallium-201 single-photon emission computed tomography (SPECT) and then CAG within 3 months. Image acquisition was performed in the supine and prone positions after stress for 5 and 3 min, respectively, and in the supine position at rest for 10 min. Significant stenosis was defined as ≥90% diameter narrowing on visual estimation, or a lesion with <90% and ≥50% stenosis and FFR ≤0.75. To detect individual coronary stenosis, the respective sensitivity, specificity, and accuracy were 90%, 64%, and 78% for left anterior descending coronary artery stenosis, 78%, 84%, and 81% for left circumflex stenosis, and 83%, 47%, and 60% for right coronary artery (RCA) stenosis. The combination of prone and supine imaging had a higher specificity for RCA disease than supine imaging alone (65% vs. 47%), with an improvement in accuracy from 60% to 72%. Using thallium-201 with short acquisition time, combined with prone imaging, CZT SPECT had a high diagnostic yield in detecting significant coronary stenosis as assessed using FFR.

  8. Polymorphic one-dimensional (N2H4)2ZnTe: soluble precursors for the formation of hexagonal or cubic zinc telluride.

    Science.gov (United States)

    Mitzi, David B

    2005-10-03

    Two hydrazine zinc(II) telluride polymorphs, (N2H4)2ZnTe, have been isolated, using ambient-temperature solution-based techniques, and the crystal structures determined: alpha-(N2H4)2ZnTe (1) [P21, a = 7.2157(4) Angstroms, b = 11.5439(6) Angstroms, c = 7.3909(4) Angstroms, beta = 101.296(1) degrees, Z = 4] and beta-(N2H4)2ZnTe (2) [Pn, a = 8.1301(5) Angstroms, b = 6.9580(5) Angstroms, c = 10.7380(7) Angstroms, beta = 91.703(1) degrees, Z = 4]. The zinc atoms in 1 and 2 are tetrahedrally bonded to two terminal hydrazine molecules and two bridging tellurium atoms, leading to the formation of extended one-dimensional (1-D) zinc telluride chains, with different chain conformations and packings distinguishing the two polymorphs. Thermal decomposition of (N2H4)2ZnTe first yields crystalline wurtzite (hexagonal) ZnTe at temperatures as low as 200 degrees C, followed by the more stable zinc blende (cubic) form at temperatures above 350 degrees C. The 1-D polymorphs are soluble in hydrazine and can be used as convenient precursors for the low-temperature solution processing of p-type ZnTe semiconducting films.

  9. Solar thermal production of zinc: Program strategy

    Energy Technology Data Exchange (ETDEWEB)

    Steinfeld, A; Weidenkaff, A; Moeller, S; Palumbo, R [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    The solar thermal production of zinc is considered for the conversion of solar energy into storable and transportable chemical fuels. The ultimate objective is to develop a technically and economically viable technology that can produce solar zinc. The program strategy for achieving such a goal involves research on two paths: a direct path via the solar thermal splitting of ZnO in the absence of fossil fuels, and an indirect path via the solar carbothermal/CH{sub 4}-thermal reduction of Zn O, with fossil fuels (coke or natural gas) as chemical reducing agents. Both paths make use of concentrated solar energy for high-temperature process heat. The direct path brings us to the complete substitution of fossil fuels with solar fuels for a sustainable energy supply system. The indirect path creates a link between today`s fossil-fuel-based technology and tomorrow`s solar chemical technology and builds bridges between present and future energy economies. (author) 1 fig., 15 refs.

  10. Material properties of large-volume cadmium zinc telluride crystals and their relationship to nuclear detector performance

    Energy Technology Data Exchange (ETDEWEB)

    James, R.B.; Lund, J. [Sandia National Labs., Livermore, CA (United States); Yoon, H. [Sandia National Labs., Livermore, CA (United States)]|[Univ. of California, Los Angeles, CA (United States)] [and others

    1997-09-01

    The material showing the greatest promise today for production of large-volume gamma-ray spectrometers operable at room temperature is cadmium zinc telluride (CZT). Unfortunately, because of deficiencies in the quality of the present material, high-resolution CZT spectrometers have thus far been limited to relatively small dimensions, which makes them inefficient at detecting high photon energies and ineffective for weak radiation signals except in near proximity. To exploit CZT fully, it will be necessary to make substantial improvements in the material quality. Improving the material involves advances in the purity, crystallinity, and control of the electrical compensation mechanism. Sandia National Laboratories, California, in close collaboration with US industry and academia, has initiated efforts to develop a detailed understanding of the underlying material problems limiting the performance of large volume gamma-ray spectrometers and to overcome them through appropriate corrections therein. A variety of analytical and numerical techniques are employed to quantify impurities, compositional and stoichiometric variations, crystallinity, strain, bulk and surface defect states, carrier mobilities and lifetimes, electric field distributions, and contact chemistry. Data from these measurements are correlated with spatial maps of the gamma-ray and alpha particle spectroscopic response to determine improvements in the material purification, crystal growth, detector fabrication, and surface passivation procedures. The results of several analytical techniques will be discussed. The intended accomplishment of this work is to develop a low-cost, high-efficiency CZT spectrometer with an active volume of 5 cm{sup 3} and energy resolution of 1--2% (at 662 keV), which would give the US a new field capability for screening radioactive substances.

  11. Comparison between stress myocardial perfusion SPECT recorded with cadmium-zinc-telluride and Anger cameras in various study protocols

    International Nuclear Information System (INIS)

    Verger, Antoine; Karcher, Gilles; Djaballah, Wassila; Fourquet, Nicolas; Rouzet, Francois; Le Guludec, Dominique; Koehl, Gregoire; Roch, Veronique; Imbert, Laetitia; Poussier, Sylvain; Fay, Renaud; Marie, Pierre-Yves

    2013-01-01

    The results of stress myocardial perfusion SPECT could be enhanced by new cadmium-zinc-telluride (CZT) cameras, although differences compared to the results with conventional Anger cameras remain poorly known for most study protocols. This study was aimed at comparing the results of CZT and Anger SPECT according to various study protocols while taking into account the influence of obesity. The study population, which was from three different institutions equipped with identical CZT cameras, comprised 276 patients referred for study using protocols involving 201 Tl (n = 120) or 99m Tc-sestamibi injected at low dose at stress ( 99m Tc-Low; stress/rest 1-day protocol; n = 110) or at high dose at stress ( 99m Tc-High; rest/stress 1-day or 2-day protocol; n = 46). Each Anger SPECT scan was followed by a high-speed CZT SPECT scan (2 to 4 min). Agreement rates between CZT and Anger SPECT were good irrespective of the study protocol (for abnormal SPECT, 201 Tl 92 %, 99m Tc-Low 86 %, 99m Tc-High 98 %), although quality scores were much higher for CZT SPECT with all study protocols. Overall correlations were high for the extent of myocardial infarction (r = 0.80) and a little lower for ischaemic areas (r = 0.72), the latter being larger on Anger SPECT (p 201 Tl or 99m Tc-Low group and in whom stress myocardial counts were particularly low with Anger SPECT (228 ± 101 kcounts) and dramatically enhanced with CZT SPECT (+279 ± 251 %). Concordance between the results of CZT and Anger SPECT is good regardless of study protocol and especially when excluding obese patients who have low-count Anger SPECT and for whom myocardial counts are dramatically enhanced on CZT SPECT. (orig.)

  12. Comparison between stress myocardial perfusion SPECT recorded with cadmium-zinc-telluride and Anger cameras in various study protocols

    Energy Technology Data Exchange (ETDEWEB)

    Verger, Antoine; Karcher, Gilles [CHU-Nancy, Department of Nuclear Medicine, Nancy (France); INSERM U947, Nancy (France); Nancyclotep Experimental Imaging Platform, Nancy (France); Djaballah, Wassila [CHU-Nancy, Department of Nuclear Medicine, Nancy (France); INSERM U947, Nancy (France); Fourquet, Nicolas [Clinique Pasteur, Toulouse (France); Rouzet, Francois; Le Guludec, Dominique [AP-HP, Hopital Bichat, Department of Nuclear Medicine, Paris (France); INSERM U 773 Inserm and Denis Diderot University, Paris (France); Koehl, Gregoire; Roch, Veronique [CHU-Nancy, Department of Nuclear Medicine, Nancy (France); Nancyclotep Experimental Imaging Platform, Nancy (France); Imbert, Laetitia [CHU-Nancy, Department of Nuclear Medicine, Nancy (France); Nancyclotep Experimental Imaging Platform, Nancy (France); Centre Alexis Vautrin, Department of Radiotherapy, Vandoeuvre (France); Poussier, Sylvain [INSERM U947, Nancy (France); Nancyclotep Experimental Imaging Platform, Nancy (France); Fay, Renaud [INSERM, Centre d' Investigation Clinique CIC-P 9501, Nancy (France); Marie, Pierre-Yves [CHU-Nancy, Department of Nuclear Medicine, Nancy (France); Nancyclotep Experimental Imaging Platform, Nancy (France); INSERM U961, Nancy (France); Hopital de Brabois, CHU-Nancy, Medecine Nucleaire, Vandoeuvre-les-Nancy (France)

    2013-03-15

    The results of stress myocardial perfusion SPECT could be enhanced by new cadmium-zinc-telluride (CZT) cameras, although differences compared to the results with conventional Anger cameras remain poorly known for most study protocols. This study was aimed at comparing the results of CZT and Anger SPECT according to various study protocols while taking into account the influence of obesity. The study population, which was from three different institutions equipped with identical CZT cameras, comprised 276 patients referred for study using protocols involving {sup 201}Tl (n = 120) or {sup 99m}Tc-sestamibi injected at low dose at stress ({sup 99m}Tc-Low; stress/rest 1-day protocol; n = 110) or at high dose at stress ({sup 99m}Tc-High; rest/stress 1-day or 2-day protocol; n = 46). Each Anger SPECT scan was followed by a high-speed CZT SPECT scan (2 to 4 min). Agreement rates between CZT and Anger SPECT were good irrespective of the study protocol (for abnormal SPECT, {sup 201}Tl 92 %, {sup 99m}Tc-Low 86 %, {sup 99m}Tc-High 98 %), although quality scores were much higher for CZT SPECT with all study protocols. Overall correlations were high for the extent of myocardial infarction (r = 0.80) and a little lower for ischaemic areas (r = 0.72), the latter being larger on Anger SPECT (p < 0.001). This larger extent was mainly observed in 50 obese patients who were in the {sup 201}Tl or {sup 99m}Tc-Low group and in whom stress myocardial counts were particularly low with Anger SPECT (228 {+-} 101 kcounts) and dramatically enhanced with CZT SPECT (+279 {+-} 251 %). Concordance between the results of CZT and Anger SPECT is good regardless of study protocol and especially when excluding obese patients who have low-count Anger SPECT and for whom myocardial counts are dramatically enhanced on CZT SPECT. (orig.)

  13. Myocardial perfusion imaging with a cadmium zinc telluride-based gamma camera versus invasive fractional flow reserve

    Energy Technology Data Exchange (ETDEWEB)

    Mouden, Mohamed [Isala klinieken, Department of Cardiology, Zwolle (Netherlands); Isala klinieken, Department of Nuclear Medicine, Zwolle (Netherlands); Ottervanger, Jan Paul; Timmer, Jorik R. [Isala klinieken, Department of Cardiology, Zwolle (Netherlands); Knollema, Siert; Reiffers, Stoffer; Oostdijk, Ad H.J.; Jager, Pieter L. [Isala klinieken, Department of Nuclear Medicine, Zwolle (Netherlands); Boer, Menko-Jan de [University Medical Centre Nijmegen, Department of Cardiology, Nijmegen (Netherlands)

    2014-05-15

    Recently introduced ultrafast cardiac SPECT cameras with cadmium zinc telluride-based (CZT) detectors may provide superior image quality allowing faster acquisition with reduced radiation doses. Although the level of concordance between conventional SPECT and invasive fractional flow reserve (FFR) measurement has been studied, that between FFR and CZT-based SPECT is not yet known. Therefore, we aimed to assess the level of concordance between CZT SPECT and FFR in a large patient group with stable coronary artery disease. Both invasive FFR and myocardial perfusion imaging with a CZT-based SPECT camera, using Tc-tetrofosmin as tracer, were performed in 100 patients with stable angina and intermediate grade stenosis on invasive coronary angiography. A cut-off value of <0.75 was used to define abnormal FFR. The mean age of the patients was 64 ± 11 years, and 64 % were men. SPECT demonstrated ischaemia in 31 % of the patients, and 20 % had FFR <0.75. The concordance between CZT SPECT and FFR was 73 % on a per-patient basis and 79 % on a per-vessel basis. Discordant findings were more often seen in older patients and were mainly (19 %) the result of ischaemic SPECT findings in patients with FFR ≥0.75, whereas only 8 % had an abnormal FFR without ischaemia as demonstrated by CZT SPECT. Only 20 - 30 % of patients with intermediate coronary stenoses had significant ischaemia as assessed by CZT SPECT or invasive FFR. CZT SPECT showed a modest degree of concordance with FFR, which is comparable with previous results with conventional SPECT. Further investigations are particularly necessary in patients with normal SPECT and abnormal FFR, especially to determine whether these patients should undergo revascularization. (orig.)

  14. Material properties of large-volume cadmium zinc telluride crystals and their relationship to nuclear detector performance

    International Nuclear Information System (INIS)

    James, R.B.; Lund, J.; Yoon, H.

    1997-01-01

    The material showing the greatest promise today for production of large-volume gamma-ray spectrometers operable at room temperature is cadmium zinc telluride (CZT). Unfortunately, because of deficiencies in the quality of the present material, high-resolution CZT spectrometers have thus far been limited to relatively small dimensions, which makes them inefficient at detecting high photon energies and ineffective for weak radiation signals except in near proximity. To exploit CZT fully, it will be necessary to make substantial improvements in the material quality. Improving the material involves advances in the purity, crystallinity, and control of the electrical compensation mechanism. Sandia National Laboratories, California, in close collaboration with US industry and academia, has initiated efforts to develop a detailed understanding of the underlying material problems limiting the performance of large volume gamma-ray spectrometers and to overcome them through appropriate corrections therein. A variety of analytical and numerical techniques are employed to quantify impurities, compositional and stoichiometric variations, crystallinity, strain, bulk and surface defect states, carrier mobilities and lifetimes, electric field distributions, and contact chemistry. Data from these measurements are correlated with spatial maps of the gamma-ray and alpha particle spectroscopic response to determine improvements in the material purification, crystal growth, detector fabrication, and surface passivation procedures. The results of several analytical techniques will be discussed. The intended accomplishment of this work is to develop a low-cost, high-efficiency CZT spectrometer with an active volume of 5 cm 3 and energy resolution of 1--2% (at 662 keV), which would give the US a new field capability for screening radioactive substances

  15. Design study of a high-resolution breast-dedicated PET system built from cadmium zinc telluride detectors

    International Nuclear Information System (INIS)

    Peng Hao; Levin, Craig S

    2010-01-01

    We studied the performance of a dual-panel positron emission tomography (PET) camera dedicated to breast cancer imaging using Monte Carlo simulation. The proposed system consists of two 4 cm thick 12 x 15 cm 2 area cadmium zinc telluride (CZT) panels with adjustable separation, which can be put in close proximity to the breast and/or axillary nodes. Unique characteristics distinguishing the proposed system from previous efforts in breast-dedicated PET instrumentation are the deployment of CZT detectors with superior spatial and energy resolution, using a cross-strip electrode readout scheme to enable 3D positioning of individual photon interaction coordinates in the CZT, which includes directly measured photon depth-of-interaction (DOI), and arranging the detector slabs edge-on with respect to incoming 511 keV photons for high photon sensitivity. The simulation results show that the proposed CZT dual-panel PET system is able to achieve superior performance in terms of photon sensitivity, noise equivalent count rate, spatial resolution and lesion visualization. The proposed system is expected to achieve ∼32% photon sensitivity for a point source at the center and a 4 cm panel separation. For a simplified breast phantom adjacent to heart and torso compartments, the peak noise equivalent count (NEC) rate is predicted to be ∼94.2 kcts s -1 (breast volume: 720 cm 3 and activity concentration: 3.7 kBq cm -3 ) for a ∼10% energy window around 511 keV and ∼8 ns coincidence time window. The system achieves 1 mm intrinsic spatial resolution anywhere between the two panels with a 4 cm panel separation if the detectors have DOI resolution less than 2 mm. For a 3 mm DOI resolution, the system exhibits excellent sphere resolution uniformity (σ rms /mean) ≤ 10%) across a 4 cm width FOV. Simulation results indicate that the system exhibits superior hot sphere visualization and is expected to visualize 2 mm diameter spheres with a 5:1 activity concentration ratio within

  16. and Cadmium Zinc Telluride

    African Journals Online (AJOL)

    Bheema

    INTRODUCTION. Semiconductor nanoparticles or Quantum Dots (QDs), in particular II-VI materials, have ... the study of structural, electronic transport and optical properties of Zn doped CdTe thin films, ...... Bhattacharya, S.K & Anjali, K. 2007.

  17. Pre-chemotherapy values for left and right ventricular volumes and ejection fraction by gated tomographic radionuclide angiography using a cadmium-zinc-telluride detector gamma camera

    DEFF Research Database (Denmark)

    Haarmark, Christian; Haase, Christine; Jensen, Maria Maj

    2016-01-01

    age and both left and right ventricular volumes in women (r = -0.4, P right end systolic ventricular volume in men (r = -0.3, P = .001). CONCLUSION: A set of reference values for cardiac evaluation prior to chemotherapy in cancer patients without other known cardiopulmonary......BACKGROUND: Estimation of left ventricular ejection fraction (LVEF) using equilibrium radionuclide angiography is an established method for assessment of left ventricular function. The purpose of this study was to establish normative data on left and right ventricular volumes and ejection fraction......, using cadmium-zinc-telluride SPECT camera. METHODS AND RESULTS: From routine assessments of left ventricular function in 1172 patients, we included 463 subjects (194 men and 269 women) without diabetes, previous potentially cardiotoxic chemotherapy, known cardiovascular or pulmonary disease. The lower...

  18. Performance of cardiac cadmium-zinc-telluride gamma camera imaging in coronary artery disease: a review from the cardiovascular committee of the European Association of Nuclear Medicine (EANM)

    International Nuclear Information System (INIS)

    Agostini, Denis; Marie, Pierre-Yves; Ben-Haim, Simona; Rouzet, Francois; Songy, Bernard; Giordano, Alessandro; Gimelli, Alessia; Hyafil, Fabien; Sciagra, Roberto; Bucerius, Jan; Verberne, Hein J.; Slart, Riemer H.J.A.; Lindner, Oliver

    2016-01-01

    The trade-off between resolution and count sensitivity dominates the performance of standard gamma cameras and dictates the need for relatively high doses of radioactivity of the used radiopharmaceuticals in order to limit image acquisition duration. The introduction of cadmium-zinc-telluride (CZT)-based cameras may overcome some of the limitations against conventional gamma cameras. CZT cameras used for the evaluation of myocardial perfusion have been shown to have a higher count sensitivity compared to conventional single photon emission computed tomography (SPECT) techniques. CZT image quality is further improved by the development of a dedicated three-dimensional iterative reconstruction algorithm, based on maximum likelihood expectation maximization (MLEM), which corrects for the loss in spatial resolution due to line response function of the collimator. All these innovations significantly reduce imaging time and result in a lower patient's radiation exposure compared with standard SPECT. To guide current and possible future users of the CZT technique for myocardial perfusion imaging, the Cardiovascular Committee of the European Association of Nuclear Medicine, starting from the experience of its members, has decided to examine the current literature regarding procedures and clinical data on CZT cameras. The committee hereby aims (1) to identify the main acquisitions protocols; (2) to evaluate the diagnostic and prognostic value of CZT derived myocardial perfusion, and finally (3) to determine the impact of CZT on radiation exposure. (orig.)

  19. Performance of cardiac cadmium-zinc-telluride gamma camera imaging in coronary artery disease: a review from the cardiovascular committee of the European Association of Nuclear Medicine (EANM)

    Energy Technology Data Exchange (ETDEWEB)

    Agostini, Denis [CHU Caen and Normandy University, Department of Nuclear Medicine, Caen (France); Normandy University, Caen (France); Marie, Pierre-Yves [University of Lorraine, Faculty of Medicine, Nancyclotep Experimental Imaging Platform, Nancy (France); University of Lorraine, Faculty of Medicine, CHU Nancy, Department of Nuclear Medicine, Nancy (France); University of Lorraine, Faculty of Medicine, Nancy (France); Ben-Haim, Simona [University College London, University College Hospital, Institute of Nuclear Medicine, London (United Kingdom); Chaim Sheba Medical Center, Department of Nuclear Medicine, Ramat Gan (Israel); Rouzet, Francois [University Hospital of Paris-Bichat, UMR 1148, Inserm et Paris Diderot-Paris 7 University Paris, Department of Nuclear Medicine, Paris (France); UMR 1148, Inserm and Paris Diderot-Paris 7 University Paris, Paris (France); Songy, Bernard [Centre Cardiologique du Nord, Saint-Denis (France); Giordano, Alessandro [Institute of Nuclear Medicine, Catholic University of Sacred Heart, Largo A. Gemelli, Department of Bioimages and Radiological Sciences, Rome (Italy); Gimelli, Alessia [Fondazione Toscana Gabriele Monasterio, Pisa (Italy); Hyafil, Fabien [Bichat University Hospital, Assistance Publique - Hopitaux de Paris, UMR 1148, Inserm and Paris Diderot-Paris 7 University, Department of Nuclear Medicine, Paris (France); Sciagra, Roberto [University of Florence, Nuclear Medicine Unit, Department of Experimental and Clinical Biomedical Sciences, Florence (Italy); Bucerius, Jan [Maastricht University Medical Center, Maastricht University Medical Center, Department of Nuclear Medicine, Maastricht (Netherlands); Maastricht University Medical Center, Cardiovascular Research Institute Maastricht (CARIM), Maastricht (Netherlands); University Hospital RWTH Aachen, Department of Nuclear Medicine, Aachen (Germany); Verberne, Hein J. [Academic Medical Center, Department of Nuclear Medicine, Amsterdam (Netherlands); Slart, Riemer H.J.A. [University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); University of Twente, Faculty of Science and Technology, Department of Biomedical Photonic Imaging, Enschede (Netherlands); Lindner, Oliver [Institute of Radiology, Nuclear Medicine and Molecular Imaging, Heart and Diabetes Center NRW, Bad Oeynhausen (Germany); Collaboration: Cardiovascular Committee of the European Association of Nuclear Medicine (EANM)

    2016-12-15

    The trade-off between resolution and count sensitivity dominates the performance of standard gamma cameras and dictates the need for relatively high doses of radioactivity of the used radiopharmaceuticals in order to limit image acquisition duration. The introduction of cadmium-zinc-telluride (CZT)-based cameras may overcome some of the limitations against conventional gamma cameras. CZT cameras used for the evaluation of myocardial perfusion have been shown to have a higher count sensitivity compared to conventional single photon emission computed tomography (SPECT) techniques. CZT image quality is further improved by the development of a dedicated three-dimensional iterative reconstruction algorithm, based on maximum likelihood expectation maximization (MLEM), which corrects for the loss in spatial resolution due to line response function of the collimator. All these innovations significantly reduce imaging time and result in a lower patient's radiation exposure compared with standard SPECT. To guide current and possible future users of the CZT technique for myocardial perfusion imaging, the Cardiovascular Committee of the European Association of Nuclear Medicine, starting from the experience of its members, has decided to examine the current literature regarding procedures and clinical data on CZT cameras. The committee hereby aims (1) to identify the main acquisitions protocols; (2) to evaluate the diagnostic and prognostic value of CZT derived myocardial perfusion, and finally (3) to determine the impact of CZT on radiation exposure. (orig.)

  20. Diagnostic Performance of a Cadmium-Zinc-Telluride Single-Photon Emission Computed Tomography System With Low-Dose Technetium-99m as Assessed by Fractional Flow Reserve.

    Science.gov (United States)

    Chikamori, Taishiro; Hida, Satoshi; Tanaka, Nobuhiro; Igarashi, Yuko; Yamashita, Jun; Shiba, Chie; Murata, Naotaka; Hoshino, Kou; Hokama, Yohei; Yamashina, Akira

    2016-04-25

    Although stress single-photon emission computed tomography (SPECT) using a cadmium-zinc-telluride (CZT) camera facilitates radiation dose reduction, only a few studies have evaluated its diagnostic accuracy in Japanese patients by applying fractional flow reserve (FFR) measurements. We prospectively evaluated 102 consecutive patients with suspected or known coronary artery disease with a low-dose stress/rest protocol ((99m)Tc radiotracer 185/370 MBq) using CZT SPECT. Within 3 months, coronary angiography was performed and a significant stenosis was defined as ≥90% diameter narrowing on visual estimation, or as a lesion of <90% and ≥ 50% stenosis with FFR ≤0.80. To detect individual coronary stenosis, the respective sensitivity, specificity, and accuracy were 86%, 75%, and 82% for left anterior descending artery stenosis, 76%, 81%, and 79% for left circumflex artery stenosis, and 87%, 92%, and 90% for right coronary artery stenosis. When limited to 92 intermediate stenotic lesions in which FFR was measured, stress SPECT showed 77% sensitivity, 91% specificity, and 84% accuracy, whereas the diagnostic value decreased to 52% sensitivity, 68% specificity, and 58% accuracy based only on visual estimation of ≥75% diameter narrowing. CZT SPECT demonstrated a good diagnostic yield in detecting hemodynamically significant coronary stenoses as assessed by FFR, even when using a low-dose (99m)Tc protocol with an effective dose ≤5 mSv. (Circ J 2016; 80: 1217-1224).

  1. Film thickness and chemical processing effects on the stability of cadmium telluride solar cells

    International Nuclear Information System (INIS)

    Albin, D.S.; Demtsu, S.H.; McMahon, T.J.

    2006-01-01

    The performance and stability of CdS/CdTe solar cells as a function of layer thickness, back contact etch, and oxygen during the CdCl 2 anneal was determined. Multiple linear regression models were used to analyze the statistical significance of various first order effects and interactions. With stress, all devices showed a reduction in open-circuit voltage (V oc ) and fill factor (FF) characteristic of increased recombination. Devices using thinner CdS were vulnerable to shunt formation. Oxygen during the CdCl 2 anneal minimizes this effect. A thermodynamic model involving the formation of Cu-oxide is presented to explain the latter

  2. (99m)Tc-MDP bone scintigraphy of the hand: comparing the use of novel cadmium zinc telluride (CZT) and routine NaI(Tl) detectors.

    Science.gov (United States)

    Koulikov, Victoria; Lerman, Hedva; Kesler, Mikhail; Even-Sapir, Einat

    2015-12-01

    Cadmium zinc telluride (CZT) solid-state detectors have been recently introduced in the field of nuclear medicine in cardiology and breast imaging. The aim of the current study was to evaluate the performance of the novel detectors (CZT) compared to that of the routine NaI(Tl) in bone scintigraphy. A dual-headed CZT-based camera dedicated originally to breast imaging has been used, and in view of the limited size of the detectors, the hands were chosen as the organ for assessment. This is a clinical study. Fifty-eight consecutive patients (total 116 hands) referred for bone scan for suspected hand pathology gave their informed consent to have two acquisitions, using the routine camera and the CZT-based camera. The latter was divided into full-dose full-acquisition time (FD CZT) and reduced-dose short-acquisition time (RD CZT) on CZT technology, so three image sets were available for analysis. Data analysis included comparing the detection of hot lesions and identification of the metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints. A total of 69 hot lesions were detected on the CZT image sets; of these, 61 were identified as focal sites of uptake on NaI(Tl) data. On FD CZT data, 385 joints were identified compared to 168 on NaI(Tl) data (p < 0.001). There was no statistically significant difference in delineation of joints between FD and RD CZT data as the latter identified 383 joints. Bone scintigraphy using a CZT-based gamma camera is associated with improved lesion detection and anatomic definition. The superior physical characteristics of this technique raised a potential reduction in administered dose and/or acquisition time without compromising image quality.

  3. 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

  4. Zinc-oxide-based nanostructured materials for heterostructure solar cells

    International Nuclear Information System (INIS)

    Bobkov, A. A.; Maximov, A. I.; Moshnikov, V. A.; Somov, P. A.; Terukov, E. I.

    2015-01-01

    Results obtained in the deposition of nanostructured zinc-oxide layers by hydrothermal synthesis as the basic method are presented. The possibility of controlling the structure and morphology of the layers is demonstrated. The important role of the procedure employed to form the nucleating layer is noted. The faceted hexagonal nanoprisms obtained are promising for the fabrication of solar cells based on oxide heterostructures, and aluminum-doped zinc-oxide layers with petal morphology, for the deposition of an antireflection layer. The results are compatible and promising for application in flexible electronics

  5. Dye-sensitized solar cells based on nanostructured zinc oxide

    Energy Technology Data Exchange (ETDEWEB)

    Conradt, Jonas; Maier-Flaig, Florian; Sartor, Janos; Fallert, Johannes [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Szmytkowski, Jedrzej; Kalt, Heinz [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Center for Functional Nanostructures (CFN), Karlsruhe (Germany); Reinhard, Manuel; Colsmann, Alexander [Karlsruhe Institute of Technology (KIT), Lichttechnisches Institut, Karlsruhe (Germany); Lemmer, Uli [Center for Functional Nanostructures (CFN), Karlsruhe (Germany); Karlsruhe Institute of Technology (KIT), Lichttechnisches Institut, Karlsruhe (Germany); Balaban, Teodor Silviu [Center for Functional Nanostructures (CFN), Karlsruhe (Germany); Karlsruhe Institute of Technology (KIT), Institute for Nanotechnology, Karlsruhe (Germany)

    2009-07-01

    Hybrid solar cells represent a promising (cost-efficient) alternative to pure inorganic solar cells. We present dye-sensitized solar cells (DSSC) which are based on a zinc oxide (ZnO) electrode covered with a ruthenium dye. Our work focuses on the morphology of the ZnO electrode and its impact on the photovoltaic performance of the solar cell. Nanocrystalline ZnO powder layers and arrays of nanorods are incorporated into the DSSCs. The ZnO nanorods are grown by vapor transport deposition. The morphology and doping concentration of the rods can be controlled by the choice of substrate material, growth condition and catalytic metal layers. The nanorod arrays are expected to fasten the electron transport towards the anode and thereby improve the solar cell efficiency. In addition, novel self-assembling (porphyrin) dyes are tested as sensitizer within a DSSC.

  6. Zinc

    Science.gov (United States)

    ... Consumer Datos en español Health Professional Other Resources Zinc Fact Sheet for Consumers Have a question? Ask ... find out more about zinc? Disclaimer What is zinc and what does it do? Zinc is a ...

  7. Comparison of conventional and cadmium-zinc-telluride single-photon emission computed tomography for analysis of thallium-201 myocardial perfusion imaging: an exploratory study in normal databases for different ethnicities.

    Science.gov (United States)

    Ishihara, Masaru; Onoguchi, Masahisa; Taniguchi, Yasuyo; Shibutani, Takayuki

    2017-12-01

    The aim of this study was to clarify the differences in thallium-201-chloride (thallium-201) myocardial perfusion imaging (MPI) scans evaluated by conventional anger-type single-photon emission computed tomography (conventional SPECT) versus cadmium-zinc-telluride SPECT (CZT SPECT) imaging in normal databases for different ethnic groups. MPI scans from 81 consecutive Japanese patients were examined using conventional SPECT and CZT SPECT and analyzed with the pre-installed quantitative perfusion SPECT (QPS) software. We compared the summed stress score (SSS), summed rest score (SRS), and summed difference score (SDS) for the two SPECT devices. For a normal MPI reference, we usually use Japanese databases for MPI created by the Japanese Society of Nuclear Medicine, which can be used with conventional SPECT but not with CZT SPECT. In this study, we used new Japanese normal databases constructed in our institution to compare conventional and CZT SPECT. Compared with conventional SPECT, CZT SPECT showed lower SSS (p < 0.001), SRS (p = 0.001), and SDS (p = 0.189) using the pre-installed SPECT database. In contrast, CZT SPECT showed no significant difference from conventional SPECT in QPS analysis using the normal databases from our institution. Myocardial perfusion analyses by CZT SPECT should be evaluated using normal databases based on the ethnic group being evaluated.

  8. Zinc oxide based dye sensitized solar cell using eosin – Y as ...

    African Journals Online (AJOL)

    A zinc oxide based Dye sensitized Solar Cell (DSSC) has been fabricated, using Eosin-Y as the dye adsorbed on a nanocrystalline zinc oxide - fluorine doped tin oxide electrode, for the sensitization of the large band gap semiconductor. The absorption spectrum of Eosin-Y showed high absorption of visible light between ...

  9. Leaching of cadmium and tellurium from cadmium telluride (CdTe) thin-film solar panels under simulated landfill conditions

    Science.gov (United States)

    Ramos-Ruiz, Adriana; Wilkening, Jean V.; Field, James A.; Sierra-Alvarez, Reyes

    2017-01-01

    A crushed non-encapsulated CdTe thin-film solar cell was subjected to two standardized batch leaching tests (i.e., Toxicity Characteristic Leaching Procedure (TCLP) and California Waste Extraction Test (WET)) and to a continuous-flow column test to assess cadmium (Cd) and tellurium (Te) dissolution under conditions simulating the acidic- and the methanogenic phases of municipal solid waste landfills. Low levels of Cd and Te were solubilized in both batch leaching tests (leaching behavior of CdTe in the columns is related to different aqueous pH and redox conditions promoted by the microbial communities in the columns, and is in agreement with thermodynamic predictions. PMID:28472709

  10. Synthesis of ultra-long cadmium telluride nanotubes via combinational chemical transformation

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kee-Ryung; Cho, Hong-Baek; Choa, Yong-Ho, E-mail: choa15@hanyang.ac.kr

    2017-03-01

    Synthesis of high-throughput cadmium telluride (CdTe) nanotubes with an ultra-long aspect ratio is presented via a combination process concept combined with electrospinning, electrodeposition, and cationic exchange reaction. Ultra-long sacrificial silver (Ag) nanofibers were synthesized by electrospinning involving two-step calcination, and were then electrodeposited to create silver telluride nanotubes. These nanotubes underwent cationic exchange reaction in cadmium nitrate tetrahydrate solution with the aid of a ligand, tributylphosphine (TBP). Analysis showed that ultra-long pure zinc blende CdTe nanotubes were obtained with controlled dimension and uniform morphology. The thermodynamic driving force induced by the coordination of methanol solvent and TBP attributed to overcome the kinetic barrier between Ag{sub 2}Te and CdTe nanotubes, facilitating the synthesis of CdTe nanotubes. This synthetic process involving a topotactic reaction route paves a way for high-throughput extended synthesis of new chalcogenide hollow nanotubes for application in photodetectors and solar cells. - Highlights: • High throughput synthetic route of hollow CdTe nanotubes with ultra-long aspect ratio. • Chemical combination of electrospinning, electrodeposition & cation exchange reaction. • Pure zinc blende CdTe by controlled dimension & structural variation of Ag nanofibers. • Potential for the high throughput synthesis of new exotic chalcogenide nanotubes.

  11. Leaching of cadmium and tellurium from cadmium telluride (CdTe) thin-film solar panels under simulated landfill conditions.

    Science.gov (United States)

    Ramos-Ruiz, Adriana; Wilkening, Jean V; Field, James A; Sierra-Alvarez, Reyes

    2017-08-15

    A crushed non-encapsulated CdTe thin-film solar cell was subjected to two standardized batch leaching tests (i.e., Toxicity Characteristic Leaching Procedure (TCLP) and California Waste Extraction Test (WET)) and to a continuous-flow column test to assess cadmium (Cd) and tellurium (Te) dissolution under conditions simulating the acidic- and the methanogenic phases of municipal solid waste landfills. Low levels of Cd and Te were solubilized in both batch leaching tests (<8.2% and <3.6% of added Cd and Te, respectively). On the other hand, over the course of 30days, 73% of the Cd and 21% of the Te were released to the synthetic leachate of a continuous-flow column simulating the acidic landfill phase. The dissolved Cd concentration was 3.24-fold higher than the TCLP limit (1mgL -1 ), and 650-fold higher than the maximum contaminant level established by the US-EPA for this metal in drinking water (0.005mgL -1 ). In contrast, the release of Cd and Te to the effluent of the continuous-flow column simulating the methanogenic phase of a landfill was negligible. The remarkable difference in the leaching behavior of CdTe in the columns is related to different aqueous pH and redox conditions promoted by the microbial communities in the columns, and is in agreement with thermodynamic predictions. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Dye-Sensitized Solar Cells Based on High Surface Area Nanocrystalline Zinc Oxide Spheres

    Directory of Open Access Journals (Sweden)

    Pavuluri Srinivasu

    2011-01-01

    Full Text Available High surface area nanocrystalline zinc oxide material is fabricated using mesoporous nanostructured carbon as a sacrificial template through combustion process. The resulting material is characterized by XRD, N2 adsorption, HR-SEM, and HR-TEM. The nitrogen adsorption measurement indicates that the materials possess BET specific surface area ca. 30 m2/g. Electron microscopy images prove that the zinc oxide spheres possess particle size in the range of 0.12 μm–0.17 μm. The nanocrystalline zinc oxide spheres show 1.0% of energy conversion efficiency for dye-sensitized solar cells.

  13. Zinc

    Science.gov (United States)

    ... Some early research suggests that zinc supplementation increases sperm count, testosterone levels, and pregnancy rates in infertile men with low testosterone levels. Other research suggests that taking zinc can improve sperm shape in men with moderate enlargement of a ...

  14. Transparent conductive zinc oxide basics and applications in thin film solar cells

    CERN Document Server

    Klein, Andreas; Rech, Bernd

    2008-01-01

    Zinc oxide (ZnO) belongs to the class of transparent conducting oxides which can be used as transparent electrodes in electronic devices or heated windows. In this book the material properties of, the deposition technologies for, and applications of zinc oxide in thin film solar cells are described in a comprehensive manner. Structural, morphological, optical and electronic properties of ZnO are treated in this review. The editors and authors of this book are specialists in deposition, analysis and fabrication of thin-film solar cells and especially of ZnO. This book is intended as an overview and a data collection for students, engineers and scientist.

  15. Doping of germanium telluride with bismuth tellurides

    International Nuclear Information System (INIS)

    Abrikosov, N.Kh.; Karpinskij, O.G.; Makalatiya, T.Sh.; Shelimova, L.E.

    1981-01-01

    Effect of germanium telluride doping with bismuth fellurides (Bi 2 Te 3 ; BiTe; Bi 2 Te) on phase transition temperature, lattice parameters and electrophysical properties of alloys is studied. It is shown that in alloys of GeTe-Bi 2 Te 3 (BiTe)(Bi 2 Te) cross sections solid solution of GeTe with Bi 2 Te 3 , characterized by deviation from stoichiometry, and germanium in the second phase the quantity of which increases during the transition from GeTe-Bi 2 Te 3 cross section to GeTe-Bi 2 Te are in equilibrium. Lower values of holes concentration and of electric conductivity and higher values of thermo e.m.f. coefficient in comparison with alloys of GeTe-Bi 2 Te 3 cross section with the same bismuth content are characterized for GeTe-Bi 2 Te cross section alloys. It is shown that in the range of GeTe-base solid solution the α→γ phase transformation which runs trough the two-phase region (α→γ) is observed with tellurium content increase. Extension of α-phase existence region widens with the bismuth content increase. Peculiarities of interatomic interaction in GeTe-base solid solutions with isovalent and heterovalent cation substitution are considered [ru

  16. Device operation of conjugated polymer/zinc oxide bulk heterojunction solar cells

    NARCIS (Netherlands)

    Koster, L. Jan Anton; van Strien, Wouter J.; Beek, Waldo J. E.; Blom, Paul W. M.

    2007-01-01

    Solar cells based on a poly (p-phenylene vinylene) (PPV) derivative and zinc oxide nanoparticles can reach a power conversion efficiency of 1.6%. The transport of electrons and holes in these promising devices is characterized and it is found that the electron mobility is equal to 2.8 x 10(-9) m(2)

  17. Computational screening of functionalized zinc porphyrins for dye sensitized solar cells

    DEFF Research Database (Denmark)

    Ørnsø, Kristian Baruël; García Lastra, Juan Maria; Thygesen, Kristian Sommer

    2013-01-01

    separation, and high output voltage. Here we demonstrate an extensive computational screening of zinc porphyrins functionalized with electron donating side groups and electron accepting anchoring groups. The trends in frontier energy levels versus side groups are analyzed and a no-loss DSSC level alignment...... quality is estimated. Out of the initial 1029 molecules, we find around 50 candidates with level alignment qualities within 5% of the optimal limit. We show that the level alignment of five zinc porphyrin dyes which were recently used in DSSCs with high efficiencies can be further improved by simple side......An efficient dye sensitized solar cell (DSSC) is one possible solution to meet the world's rapidly increasing energy demands and associated climate challenges. This requires inexpensive and stable dyes with well-positioned frontier energy levels for maximal solar absorption, efficient charge...

  18. Copper and Zinc Oxide Composite Nanostructures for Solar Energy Harvesting

    Science.gov (United States)

    Wu, Fei

    Solar energy is a clean and sustainable energy source to counter global environmental issues of rising atmospheric CO2 levels and depletion of natural resources. To extract useful work from solar energy, silicon-based photovoltaic devices are extensively used. The technological maturity and the high quality of silicon (Si) make it a material of choice. However limitations in Si exist, ranging from its indirect band gap to low light absorption coefficient and energy and capital intensive crystal growth schemes. Therefore, alternate materials that are earth-abundant, benign and simpler to process are needed for developing new platforms for solar energy harvesting applications. In this study, we explore oxides of copper (CuO and Cu2O) in a nanowire morphology as alternate energy harvesting materials. CuO has a bandgap of 1.2 eV whereas Cu2O has a bandgap of 2.1 eV making them ideally suited for absorbing solar radiation. First, we develop a method to synthesize vertical, single crystalline CuO and Cu2O nanowires of ~50 microm length and aspect ratios of ~200. CuO nanowire arrays are synthesized by thermal oxidation of Cu foils. Cu2O nanowire arrays are synthesized by thermal reduction of CuO nanowires. Next, surface engineering of these nanowires is achieved using atomic layer deposition (ALD) of ZnO. By depositing 1.4 nm of ZnO, a highly defective surface is produced on the CuO nanowires. These defects are capable of trapping charge as is evident through persistent photoconductivity measurements of ZnO coated CuO nanowires. The same nanowires serve as efficient photocatalysts reducing CO2 to CO with a yield of 1.98 mmol/g-cat/hr. Finally, to develop a robust platform for flexible solar cells, a protocol to transfer vertical CuO nanowires inside flexible polydimethylsiloxane (PDMS) is demonstrated. Embedded CuO nanowires-ZnO pn junctions show a VOC of 0.4 V and a JSC of 10.4 microA/cm2 under white light illumination of 5.7 mW/cm2. Thus, this research provides broad

  19. Semiconductor materials for solar photovoltaic cells

    CERN Document Server

    Wong-Ng, Winnie; Bhattacharya, Raghu

    2016-01-01

    This book reviews the current status of semiconductor materials for conversion of sunlight to electricity, and highlights advances in both basic science and manufacturing.  Photovoltaic (PV) solar electric technology will be a significant contributor to world energy supplies when reliable, efficient PV power products are manufactured in large volumes at low cost.  Expert chapters cover the full range of semiconductor materials for solar-to-electricity conversion, from crystalline silicon and amorphous silicon to cadmium telluride, copper indium gallium sulfide selenides, dye sensitized solar cells, organic solar cells, and environmentally friendly copper zinc tin sulfide selenides. The latest methods for synthesis and characterization of solar cell materials are described, together with techniques for measuring solar cell efficiency. Semiconductor Materials for Solar Photovoltaic Cells presents the current state of the art as well as key details about future strategies to increase the efficiency and reduce ...

  20. Economic evaluation of the solar thermal co-production of zinc, synthesis gas, and hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Steinfeld, A [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Spiewak, I [EC Joint Research Centre (Spain)

    1999-08-01

    The use of concentrated solar energy for co-producing Zn and synthesis gas from Zn O and natural gas upgrades the calorific value of the initial reactants by 39% and, when compared to the traditional carbothermic reduction of Zn O, has the potential of reducing CO{sub 2} emissions by up to 78%. An economic assessment for an industrial thermochemical plant, 30 to 51 MW solar input, indicates that the cost of solar production of zinc ranges between 89-133 $/t (excluding the cost of Zn O feed and credit for pollution abatement), and thus might be competitive with conventional fossil-fuel-based processes at current fuel prices. The cost of solar H{sub 2}, produced by splitting water with zinc, is estimated to be in the range 0.10-0.14 $/kWh, and it is a favorable long term prospect once the cost of energy will account for the environmental externalities from fossil fuel burning such as the costs for CO{sub 2} mitigation and pollution abatement. (author) 1 fig., 2 tabs., 5 refs.

  1. A facile route to inverted polymer solar cells using a precursor based zinc oxide electron transport layer

    NARCIS (Netherlands)

    Bruyn, P. de; Moet, D.J.D.; Blom, P.W.M.

    2010-01-01

    Inverted polymer:fullerene solar cells with ZnO and MoO3 transport layers are demonstrated. ZnO films are prepared through spin casting of a zinc acetylacetonate hydrate solution, followed by low temperature annealing under ambient conditions. The performance of solar cells with an inverted

  2. A facile route to inverted polymer solar cells using a precursor based zinc oxide electron transport layer

    NARCIS (Netherlands)

    de Bruyn, P.; Moet, D. J. D.; Blom, P. W. M.

    Inverted polymer: fullerene solar cells with ZnO and MoO(3) transport layers are demonstrated. ZnO films are prepared through spin casting of a zinc acetylacetonate hydrate solution, followed by low temperature annealing under ambient conditions. The performance of solar cells with an inverted

  3. Zinc chlorophyll aggregates as hole transporters for biocompatible, natural-photosynthesis-inspired solar cells

    Science.gov (United States)

    Li, Yue; Sasaki, Shin-ichi; Tamiaki, Hitoshi; Liu, Cheng-Liang; Song, Jiaxing; Tian, Wenjing; Zheng, Enqiang; Wei, Yingjin; Chen, Gang; Fu, Xueqi; Wang, Xiao-Feng

    2015-11-01

    The intriguing properties of extremely efficient delocalization and migration of excitons in chlorophyll (Chl) J-type aggregates have inspired intense research activities toward their structural understanding, functional interpretation and mimicry synthesis. Herein, we demonstrated the J-aggregates of zinc methyl 3-devinyl-3-hydroxymethyl-pyropheophorbide a (ZnChl-1) generated by spin-coating method for the application as a hole transporter in titania-based solar cells using methyl trans-32-carboxypyropheophorbide a (H2Chl-2) or its zinc complex (ZnChl-2) as the sensitizer. The effective carrier mobility of the J-aggregates films was determined by the organic field-effect transistor to be 6.2 × 10-4 cm2 V-1 s-1. Solar cells sharing the architecture of FTO/H2Chl-2 or ZnChl-2 on TiO2/(ZnChl-1)n/Ag were fabricated and the factors that presumably determine their photovoltaic performances were discussed. The photovoltaic devices studied herein employing inexpensive and pollution-free biomaterials provide a unique solution of utilizing solar energy with a care of the important environmental issue.

  4. Embedded vertically aligned cadmium telluride nanorod arrays grown by one-step electrodeposition for enhanced energy conversion efficiency in three-dimensional nanostructured solar cells.

    Science.gov (United States)

    Wang, Jun; Liu, Shurong; Mu, Yannan; Liu, Li; A, Runa; Yang, Jiandong; Zhu, Guijie; Meng, Xianwei; Fu, Wuyou; Yang, Haibin

    2017-11-01

    Vertically aligned CdTe nanorods (NRs) arrays are successfully grown by a simple one-step and template-free electrodeposition method, and then embedded in the CdS window layer to form a novel three-dimensional (3D) heterostructure on flexible substrates. The parameters of electrodeposition such as deposition potential and pH of the solution are varied to analyze their important role in the formation of high quality CdTe NRs arrays. The photovoltaic conversion efficiency of the solar cell based on the 3D heterojunction structure is studied in detail. In comparison with the standard planar heterojunction solar cell, the 3D heterojunction solar cell exhibits better photovoltaic performance, which can be attributed to its enhanced optical absorption ability, increased heterojunction area and improved charge carrier transport. The better photoelectric property of the 3D heterojunction solar cell suggests great application potential in thin film solar cells, and the simple electrodeposition process represents a promising technique for large-scale fabrication of other nanostructured solar energy conversion devices. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Bulk Heterojunction Solar Cell Devices Prepared with Composites of Conjugated Polymer and Zinc Oxide Nanorods

    Directory of Open Access Journals (Sweden)

    Nguyen Tam Nguyen Truong

    2017-01-01

    Full Text Available ZnO nanorods (Nrods with ~20–50 nm lengths were synthesized using an aqueous solution of zinc acetate and glacial acetic acid. Bulk heterojunction solar cells were fabricated with the structure of indium tin oxide (ITO/polyethylenedioxythiophene doped with polystyrene-sulfonic acid (PEDOT:PSS/ZnO-Nrods + polymer/electron transport layer (ETL/Al. Current density-voltage characterization of the resulting cells showed that, by adding an ETL and using polymers with a low band gap energy, the photoactive layer surface morphology and the device performance can be dramatically improved.

  6. Effects of Germanium Tetrabromide Addition to Zinc Tetraphenyl Porphyrin / Fullerene Bulk Heterojunction Solar Cells

    Directory of Open Access Journals (Sweden)

    Atsushi Suzuki

    2014-03-01

    Full Text Available The effects of germanium tetrabromide addition to tetraphenyl porphyrin zinc (Zn-TPP/fullerene (C60 bulk heterojunction solar cells were characterized. The light-induced charge separation and charge transfer were investigated by current density and optical absorption. Addition of germanium tetrabromide inserted into active layer of Zn-TPP/C60 as bulk heterojunction had a positive effect on the photovoltaic and optical properties. The photovoltaic mechanism of the solar cells was discussed by experimental results. The photovoltaic performance was due to light-induced exciton promoted by insert of GeBr4 and charge transfer from HOMO of Zn-TPP to LUMO of C60 in the active layer.

  7. Efficient inverted bulk-heterojunction polymer solar cells with self-assembled monolayer modified zinc oxide.

    Science.gov (United States)

    Kim, Wook Hyun; Lyu, Hong-Kun; Han, Yoon Soo; Woo, Sungho

    2013-10-01

    The performance of poly(3-hexylthiophen) (P3HT) and [6, 6]phenyl C61 butyric acid methyl ester ([60]PCBM)-based inverted bulk-heterojunction (BHJ) polymer solar cells (PSCs) is enhanced by the modification of zinc oxide (ZnO)/BHJ interface with carboxylic-acid-functionalized self-assembled monolayers (SAMs). Under simulated solar illumination of AM 1.5 (100 mW/cm2), the inverted devices fabricated with SAM-modified ZnO achieved an enhanced power conversion efficiency (PCE) of 3.34% due to the increased fill factor and photocurrent density as compared to unmodified cells with PCE of 2.60%. This result provides an efficient method for interface engineering in inverted BHJ PSCs.

  8. Solar Light Responsive Photocatalytic Activity of Reduced Graphene Oxide-Zinc Selenide Nanocomposite

    Science.gov (United States)

    Chakraborty, Koushik; Ibrahim, Sk; Das, Poulomi; Ghosh, Surajit; Pal, Tanusri

    2017-10-01

    Solution processable reduced graphene oxide-zinc selenide (RGO-ZnSe) nanocomposite has been successfully synthesized by an easy one-pot single-step solvothermal reaction. The RGO-ZnSe composite was characterized structurally and morphologically by the study of XRD analysis, SEM and TEM imaging. Reduction in graphene oxide was confirmed by FTIR spectroscopy analysis. Photocatalytic efficiency of RGO-ZnSe composite was investigated toward the degradation of Rhodamine B under solar light irradiation. Our study indicates that the RGO-ZnSe composite is catalytically more active compared to the controlled-ZnSe under the solar light illumination. Here, RGO plays an important role for photoinduced charge separation and subsequently hinders the electron-hole recombination probability that consequently enhances photocatalytic degradation efficiency. We expect that this type of RGO-based optoelectronics materials opens up a new avenue in the field of photocatalytic degradation of different organic water pollutants.

  9. Low-cost zinc-plated photoanode for fabric-type dye-sensitized solar cells

    Science.gov (United States)

    Kong, Lingfeng; Bao, Yunna; Guo, Wanwan; Cheng, Li; Du, Jun; Liu, Renlong; Wang, Yundong; Fan, Xing; Tao, Changyuan

    2016-02-01

    Fabric-type flexible solar cells have been recently proposed as a very promising power source for wearable electronics. To increase the photocurrent of fabric-type flexible solar cells, low-cost zinc-plated wire and mesh photoanodes are assembled for the first time through a mild wet process. Given the protection of the compact protection layer, the DSSC device could benefit from the low work function of Zn and self-repairing behavior on the Zn/ZnO interface. An evident current increase by ∼6 mA/cm2 could be observed after coating a layer of metal Zn on various metal substrates, such as traditional stainless steel wire. Given the self-repairing behavior on Zn/ZnO interface, the Zn layer can help to improve the interfacial carrier transfer, leading to better photovoltaic performance, for both liquid-type and solid-type cells.

  10. Efficiency calculations and optimization analysis of a solar reactor for the high temperature step of the zinc/zinc-oxide thermochemical redox cycle

    Energy Technology Data Exchange (ETDEWEB)

    Haussener, S.

    2007-03-15

    A solar reactor for the first step of the zinc/zinc-oxide thermochemical redox cycle is analysed and dimensioned in terms of maximization of efficiency and reaction conversion. Zinc-oxide particles carried in an inert carrier gas, in our case argon, enter the reactor in absorber tubes and are heated by concentrated solar radiation mainly due to radiative heat transfer. The particles dissociate and, in case of complete conversion, a gas mixture of argon, zinc and oxygen leaves the reactor. The aim of this study is to find an optimal design of the reactor regarding efficiency, materials and economics. The number of absorber tubes and their dimensions, the cavity dimension and its material as well as the operating conditions should be determined. Therefore 2D and 3D simulations of an 8 kW reactor are implemented. The gases are modeled as ideal gases with temperature-dependent properties. Absorption and scattering of the particle gas mixture are calculated by Mie-theory. Radiative heat transfer is included in the simulation and implemented with the aid of the discrete ordinates (DO) method. The mixture is modeled as ideal mixture and the reaction with an Arrhenius-type ansatz. Temperature distribution, reaction efficiency (heat used for zinc-oxide reaction divided by input) and tube efficiency (heat going into absorber tubes divided by input) as well as reaction conversion are analyzed to find the most promising reactor design. The results show that the most significant factors for efficiencies, conversion and absorber fluid temperature are concentration of the solar incoming radiation, zinc-oxide mass flow, the number of tubes and their dimension. Higher concentration leads to solely positive effects. Zinc-oxide mass flow variations indicate the existence of an optimal flow rate for each reactor design which maximizes efficiencies and conversion. Higher zinc-oxide mass flow leads, on one hand, to higher tube efficiency but on the other hand to lower temperatures in

  11. Blade-coated sol-gel indium-gallium-zinc-oxide for inverted polymer solar cell

    Directory of Open Access Journals (Sweden)

    Yan-Huei Lee

    2016-11-01

    Full Text Available The inverted organic solar cell was fabricated by using sol-gel indium-gallium-zinc-oxide (IGZO as the electron-transport layer. The IGZO precursor solution was deposited by blade coating with simultaneous substrate heating at 120 °C from the bottom and hot wind from above. Uniform IGZO film of around 30 nm was formed after annealing at 400 °C. Using the blend of low band-gap polymer poly[(4,8-bis-(2-ethylhexyloxy-benzo(1,2-b:4,5-b’dithiophene-2,6-diyl-alt- (4-(2-ethylhexanoyl-thieno [3,4-b]thiophene--2-6-diyl] (PBDTTT-C-T and [6,6]-Phenyl C71 butyric acid methyl ester ([70]PCBM as the active layer for the inverted organic solar cell, an efficiency of 6.2% was achieved with a blade speed of 180 mm/s for the IGZO. The efficiency of the inverted organic solar cells was found to depend on the coating speed of the IGZO films, which was attributed to the change in the concentration of surface OH groups. Compared to organic solar cells of conventional structure using PBDTTT-C-T: [70]PCBM as active layer, the inverted organic solar cells showed significant improvement in thermal stability. In addition, the chemical composition, as well as the work function of the IGZO film at the surface and inside can be tuned by the blade speed, which may find applications in other areas like thin-film transistors.

  12. Low-cost zinc-plated photoanode for fabric-type dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Lingfeng; Bao, Yunna; Guo, Wanwan; Cheng, Li; Du, Jun; Liu, Renlong [College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030 (China); Wang, Yundong [Department of Chemical Engineering, Tsinghua University, State Key Lab of Chemical Engineering, Beijing 100084 (China); Fan, Xing, E-mail: foxcqdx@cqu.edu.cn [College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030 (China); Tao, Changyuan [College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030 (China)

    2016-02-15

    Graphical abstract: - Highlights: • Fabric-type flexible solar cells have been assembled on Zn-plated wires and meshes. • Metal Zn can improve the carriers transfer over the metal/ZnO nanoarrays interface. • A current increase by ∼6 mA/cm{sup 2} was realized by plating Zn on various metal substrates. • All-solid fabric-type DSSC was also assembled on Zn-plated metal wires. - Abstract: Fabric-type flexible solar cells have been recently proposed as a very promising power source for wearable electronics. To increase the photocurrent of fabric-type flexible solar cells, low-cost zinc-plated wire and mesh photoanodes are assembled for the first time through a mild wet process. Given the protection of the compact protection layer, the DSSC device could benefit from the low work function of Zn and self-repairing behavior on the Zn/ZnO interface. An evident current increase by ∼6 mA/cm{sup 2} could be observed after coating a layer of metal Zn on various metal substrates, such as traditional stainless steel wire. Given the self-repairing behavior on Zn/ZnO interface, the Zn layer can help to improve the interfacial carrier transfer, leading to better photovoltaic performance, for both liquid-type and solid-type cells.

  13. Low-cost zinc-plated photoanode for fabric-type dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Kong, Lingfeng; Bao, Yunna; Guo, Wanwan; Cheng, Li; Du, Jun; Liu, Renlong; Wang, Yundong; Fan, Xing; Tao, Changyuan

    2016-01-01

    Graphical abstract: - Highlights: • Fabric-type flexible solar cells have been assembled on Zn-plated wires and meshes. • Metal Zn can improve the carriers transfer over the metal/ZnO nanoarrays interface. • A current increase by ∼6 mA/cm"2 was realized by plating Zn on various metal substrates. • All-solid fabric-type DSSC was also assembled on Zn-plated metal wires. - Abstract: Fabric-type flexible solar cells have been recently proposed as a very promising power source for wearable electronics. To increase the photocurrent of fabric-type flexible solar cells, low-cost zinc-plated wire and mesh photoanodes are assembled for the first time through a mild wet process. Given the protection of the compact protection layer, the DSSC device could benefit from the low work function of Zn and self-repairing behavior on the Zn/ZnO interface. An evident current increase by ∼6 mA/cm"2 could be observed after coating a layer of metal Zn on various metal substrates, such as traditional stainless steel wire. Given the self-repairing behavior on Zn/ZnO interface, the Zn layer can help to improve the interfacial carrier transfer, leading to better photovoltaic performance, for both liquid-type and solid-type cells.

  14. Hybrid zinc oxide/graphene electrodes for depleted heterojunction colloidal quantum-dot solar cells.

    Science.gov (United States)

    Tavakoli, Mohammad Mahdi; Aashuri, Hossein; Simchi, Abdolreza; Fan, Zhiyong

    2015-10-07

    Recently, hybrid nanocomposites consisting of graphene/nanomaterial heterostructures have emerged as promising candidates for the fabrication of optoelectronic devices. In this work, we have employed a facile and in situ solution-based process to prepare zinc oxide/graphene quantum dots (ZnO/G QDs) in a hybrid structure. The prepared hybrid dots are composed of a ZnO core, with an average size of 5 nm, warped with graphene nanosheets. Spectroscopic studies show that the graphene shell quenches the photoluminescence intensity of the ZnO nanocrystals by about 72%, primarily due to charge transfer reactions and static quenching. A red shift in the absorption peak is also observed. Raman spectroscopy determines G-band splitting of the graphene shell into two separated sub-bands (G(+), G(-)) caused by the strain induced symmetry breaking. It is shown that the hybrid ZnO/G QDs can be used as a counter-electrode for heterojunction colloidal quantum-dot solar cells for efficient charge-carrier collection, as evidenced by the external quantum efficiency measurement. Under the solar simulated spectrum (AM 1.5G), we report enhanced power conversion efficiency (35%) with higher short current circuit (80%) for lead sulfide-based solar cells as compared to devices prepared by pristine ZnO nanocrystals.

  15. Hydrothermally Synthesized Zinc Sulphide Microspheres for Solar Light-Driven Photocatalytic Properties

    Science.gov (United States)

    Waghadkar, Yogesh; Arbuj, Sudhir; Shinde, Manish; Ballal, Reshma; Rane, Sunit B.; Gosavi, Suresh; Fouad, H.; Chauhan, Ratna

    2018-02-01

    In this work, we reported the synthesis of zinc sulphide microspheres using the hydrothermal method. ZnS microspheres were synthesized using water, zinc acetate, thiourea and ammonia solution at 150°C for 6 h, 12 h, and 24 h. The as-synthesized ZnS powders were characterized by x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and ultraviolet-visible (UV-Vis) spectroscopy. XRD indicates the cubic (major phase) as well as hexagonal (minor phase) crystalline phase with enhanced crystallinity increased gradually with more reaction time. UV-Vis spectra show the absorption peaks in the UV-Vis region for all the samples. The Tauc's plot was used to calculate the band gap energy of ZnS samples, which are found to be 3.39 eV, 3.4 eV, and 3.42 eV for the samples synthesized at reaction times of 6 h, 12 h, and 24 h, respectively. FESEM images confirm the formation of microspheres as aggregates of spherical nanoparticles. The as-synthesized ZnS microspheres have been explored for solar light-induced photo-catalytic dye degradation of methylene blue (MB), and the results confirm that such microspheres exhibit effectual photocatalytic properties.

  16. Enhancement of oxygen vacancies and solar photocatalytic activity of zinc oxide by incorporation of nonmetal

    International Nuclear Information System (INIS)

    Patil, Ashokrao B.; Patil, Kashinath R.; Pardeshi, Satish K.

    2011-01-01

    B-doped ZnO and N-doped ZnO powders have been synthesized by mechanochemical method and characterized by TG–DTA, XRD, SEM–EDX, XPS, UV–visible and photoluminescence (PL) spectra. X-ray diffraction data suggests the hexagonal wurtzite structure for modified ZnO crystallites and the incorporation of nonmetal expands the lattice constants of ZnO. The room temperature PL spectra suggest more number of oxygen vacancies exist in nonmetal-doped ZnO than that of undoped zinc oxide. XPS analysis shows the substitution of some of the O atoms of ZnO by nonmetal atoms. Solar photocatalytic activity of B-doped ZnO, N-doped ZnO and undoped ZnO was compared by means of oxidative photocatalytic degradation (PCD) of Bisphenol A (BPA). B-doped ZnO showed better solar PCD efficiency as compare to N-doped ZnO and undoped ZnO. The PCD of BPA follows first order reaction kinetics. The detail mechanism of PCD of Bisphenol A was proposed with the identification of intermediates such as hydroquinone, benzene-1,2,4-triol and 4-(2-hydroxypropan-2-yl) phenol. - Graphical Abstract: B-doped ZnO and N-doped ZnO synthesized by mechanochemical method were characterized by various techniques. Solar photocatalytic degradation of Bisphenol-A is in the order of B-ZnO>N-ZnO>ZnO. Highlights: ► B-doped ZnO and N-doped ZnO powders have been synthesized by mechanochemical method. ► PL spectra suggest oxygen vacancies are in order of B-doped ZnO>N-doped ZnO>ZnO. ► Solar PCD efficiency is in order of B-doped ZnO>N-doped ZnO>ZnO for Bisphenol A.

  17. Morphology dependent dye-sensitized solar cell properties of nanocrystalline zinc oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, S.K., E-mail: sanjeevlrs732000@yahoo.co.in [Department of Information and Communication, Cheju Halla College, Jeju City 690 708 (Korea, Republic of); Inamdar, A.I.; Im, Hyunsik [Department of Semiconductor Science, Dongguk University, Seoul 100 715 (Korea, Republic of); Kim, B.G. [Department of Information and Communication, Cheju Halla College, Jeju City 690 708 (Korea, Republic of); Patil, P.S. [Thin Film Materials Laboratory, Department of Physics, Shivaji University, Kolhapur 416 004 (India)

    2011-02-03

    Research highlights: > Nano-crystalline zinc oxide thin films were electrosynthesized from an aqueous zinc acetate [Zn(CH{sub 3}COO){sub 2}.2H{sub 2}O] solution onto FTO coated conducting glass substrates using two different electrochemical routes, namely (i) without an organic surfactant and (ii) with an organic surfactant, viz. PVA (poly-vinyl alcohol) or SDS (sodium dodecyl sulfate). > The reproducibility of the catalytic activity of the SDS and PVA surfactants in the modification of the morphologies was observed. > Vertically aligned nest-like and compact structures were observed from the SDS and PVA mediated films, respectively, while the grain size in the ZnO thin films without an organic surfactant was observed to be {approx}150 nm. > The dye sensitized ZnO electrodes displayed excellent properties in the conversion process from light to electricity. The efficiencies of the surfactant mediated nanocrystalline ZnO thin films, viz. ZnO:SDS and ZnO:PVA, sensitized with ruthenium-II (N3) dye were observed to be 0.49% and 0.27%, respectively. - Abstract: Nano-crystalline zinc oxide thin films were electrosynthesized with an aqueous zinc acetate [Zn(CH{sub 3}COO){sub 2}.2H{sub 2}O] solution on to FTO coated glass substrates. Two different electrochemical baths were used, namely (i) without an organic surfactant and (ii) with an organic surfactant, viz. PVA (poly-vinyl alcohol) and SDS (sodium dodecyl sulfate). The organic surfactants played an important role in modifying the surface morphology, which influenced the size of the crystallites and dye-sensitized solar cell (DSSC) properties. The vertically aligned thin and compact hexagonal crystallites were observed with SDS mediated films, while the grain size in the films without an organic surfactant was observed to be {approx}150 nm. The conversion efficiencies of the ZnO:SDS:Dye and ZnO:PVA:Dye thin films were observed to be 0.49% and 0.27%, respectively.

  18. Processing of Copper Zinc Tin Sulfide Nanocrystal Dispersions for Thin Film Solar Cells

    Science.gov (United States)

    Williams, Bryce Arthur

    A scalable and inexpensive renewable energy source is needed to meet the expected increase in electricity demand throughout the developed and developing world in the next 15 years without contributing further to global warming through CO2 emissions. Photovoltaics may meet this need but current technologies are less than ideal requiring complex manufacturing processes and/or use of toxic, rare-earth materials. Copper zinc tin sulfide (Cu 2ZnSnS4, CZTS) solar cells offer a true "green" alternative based upon non-toxic and abundant elements. Solution-based processes utilizing CZTS nanocrystal dispersions followed by high temperature annealing have received significant research attention due to their compatibility with traditional roll-to-roll coating processes. In this work, CZTS nanocrystal (5-35 nm diameters) dispersions were utilized as a production pathway to form solar absorber layers. Aerosol-based coating methods (aerosol jet printing and ultrasonic spray coating) were optimized for formation of dense, crack-free CZTS nanocrystal coatings. The primary variables underlying determination of coating morphology within the aerosol-coating parameter space were investigated. It was found that the liquid content of the aerosol droplets at the time of substrate impingement play a critical role. Evaporation of the liquid from the aerosol droplets during coating was altered through changes to coating parameters as well as to the CZTS nanocrystal dispersions. In addition, factors influencing conversion of CZTS nanocrystal coatings into dense, large-grained polycrystalline films suitable for solar cell development during thermal annealing were studied. The roles nanocrystal size, carbon content, sodium uptake, and sulfur pressure were found to have pivotal roles in film microstructure evolution. The effects of these parameters on film morphology, grain growth rates, and chemical makeup were analyzed from electron microscopy images as well as compositional analysis

  19. Zinc tin oxide as high-temperature stable recombination layer for mesoscopic perovskite/silicon monolithic tandem solar cells

    KAUST Repository

    Werner, Jérémie

    2016-12-05

    Perovskite/crystalline silicon tandem solar cells have the potential to reach efficiencies beyond those of silicon single-junction record devices. However, the high-temperature process of 500 °C needed for state-of-the-art mesoscopic perovskite cells has, so far, been limiting their implementation in monolithic tandem devices. Here, we demonstrate the applicability of zinc tin oxide as a recombination layer and show its electrical and optical stability at temperatures up to 500 °C. To prove the concept, we fabricate monolithic tandem cells with mesoscopic top cell with up to 16% efficiency. We then investigate the effect of zinc tin oxide layer thickness variation, showing a strong influence on the optical interference pattern within the tandem device. Finally, we discuss the perspective of mesoscopic perovskite cells for high-efficiency monolithic tandem solar cells. © 2016 Author(s)

  20. Magnetron sputtered zinc oxide nanorods as thickness-insensitive cathode interlayer for perovskite planar-heterojunction solar cells.

    Science.gov (United States)

    Liang, Lusheng; Huang, Zhifeng; Cai, Longhua; Chen, Weizhong; Wang, Baozeng; Chen, Kaiwu; Bai, Hua; Tian, Qingyong; Fan, Bin

    2014-12-10

    Suitable electrode interfacial layers are essential to the high performance of perovskite planar heterojunction solar cells. In this letter, we report magnetron sputtered zinc oxide (ZnO) film as the cathode interlayer for methylammonium lead iodide (CH3NH3PbI3) perovskite solar cell. Scanning electron microscopy and X-ray diffraction analysis demonstrate that the sputtered ZnO films consist of c-axis aligned nanorods. The solar cells based on this ZnO cathode interlayer showed high short circuit current and power conversion efficiency. Besides, the performance of the device is insensitive to the thickness of ZnO cathode interlayer. Considering the high reliability and maturity of sputtering technique both in lab and industry, we believe that the sputtered ZnO films are promising cathode interlayers for perovskite solar cells, especially in large-scale production.

  1. Solar thermal production of zinc - Final steps toward scale-up - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Meier, A.

    2008-05-15

    A 10 kW receiver-reactor prototype (called ZIRRUS) was further improved and tested for the solar thermal de-composition of ZnO, which is the 1{sup st} step of the two-step water-splitting thermochemical ZnO/Zn cycle. The rotating cylindrical cavity was made of either sintered ZnO or sintered Al{sub 2}O{sub 3} tiles placed on top of a multi-layer Al{sub 2}O{sub 3}-SiO{sub 2}-Y{sub 2}O{sub 3}-based ceramics for thermal shock resistance, mechanical stability, gas diffusion barrier, and thermal insulation. Pre-heated Ar gas was injected for aerodynamic window protection and for minimizing recombination of product gases in the cavity. Experimentation was carried out at PSI's High-Flux Solar Simulator with the direct heating 10 kW reactor prototype subjected to peak radiative fluxes exceeding 5,800 suns. The reactor operated without incident for a total of more than 40 h at maximum temperatures - measured behind the ZnO and Al{sub 2}O{sub 3} tiles - ranging from 1807-1907 K. Thermal dissociation of ZnO(s) near 2000 K was demonstrated for experimental runs over 4 h in transient ablation mode with up to nine semi-continuous feed cycles of ZnO particles. A working Zn/O{sub 2} separation device based on the rapid quenching of the Zn/O{sub 2} mixture is ready to be incorporated at the exit of the solar reactor. Zinc yields of up to 94% were obtained when using total Ar/Zn(g) dilution of 530 and a cooling rate of about 10{sup 5} K/s. The fully integrated solar reactor will be scaled up to the pilot scale of 100 kW. A newly developed reactor model that couples radiation, conduction, and convection heat transfer to the reaction kinetics will allow determining optimal operational conditions for matching the feeding rate to the reaction rate and for maximizing solar-to-chemical energy conversion efficiency. The 2{sup nd} step of the ZnO/Zn cycle has been experimentally demonstrated at ETH using an aerosol-flow reactor for in-situ formation and hydrolysis of Zn nanoparticles

  2. Influence of structural variations in push-pull zinc porphyrins on photovoltaic performance of dye-sensitized solar cells.

    Science.gov (United States)

    Yi, Chenyi; Giordano, Fabrizio; Cevey-Ha, Ngoc-Le; Tsao, Hoi Nok; Zakeeruddin, Shaik M; Grätzel, Michael

    2014-04-01

    We designed and synthesized two new zinc porphyrin dyes for dye-sensitized solar cells (DSCs). Subtle molecular structural variation in the dyes significantly influenced the performance of the DSC devices. By utilizing these dyes in combination with a cobalt-based redox electrolyte using a photoanode made of mesoporous TiO2 , we achieved a power conversion efficiency (PCE) of up to 12.0 % under AM 1.5 G (100 mW cm(-2)) simulated solar light. Moreover, we obtained a high PCE of 6.4 % for solid-state dye-sensitized solar cells by using 2,2',7,7'-tetrakis-(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene as a hole-transporting material. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. A novel self-assembly with zinc porphyrin coordination polymer for enhanced photocurrent conversion in supramolecular solar cells

    International Nuclear Information System (INIS)

    Cao, Jing; Liu, Jia-Cheng; Deng, Wen-Ting; Li, Ren-Zhi; Jin, Neng-Zhi

    2013-01-01

    Graphical abstract: An innovative type of self-assembly based on acetohydrazide zinc porphyrin coordination polymer has been prepared in supramolecular solar cells. - Highlights: • A novel assembly with acetohydrazide porphyrin coordination polymer. • The assembly based on porphyrin is prepared as parallel sample. • Coordination polymer-based assembly shows enhanced photoelectronic behavior. • A series of different organic acid ligands as anchoring groups are prepared. - Abstract: In this work, a novel acetohydrazide zinc porphyrin-based coordination polymer (CP)-isonicotinic acid self-assembly by metal-ligand axial coordination to modify the nano-structured TiO 2 electrode surface has been investigated in photoelectrochemical device. Compared to the assembly based on corresponding zinc porphyrin combined with isonicotinic acid by metal-ligand axial coordination, CP-isonicotinic acid assembly exhibits a significantly enhanced photoelectronic behavior. In addition, a series of different organic acid ligands were prepared to probe the impact of their structures on the photoelectronic performances of their corresponding assemblies-sensitized cells. This study affords a novel type of self-assembly to functionalize the nanostructured TiO 2 electrode surface in supramolecular solar cells

  4. Thin-film cadmium telluride photovoltaics: ES and H issues, solutions, and perspectives

    International Nuclear Information System (INIS)

    Zweibel, K.; Moskowitz, P.; Fthenakis, V.

    1998-02-01

    Photovoltaics (PV) is a growing business worldwide, with new technologies evolving towards potentially large-volume production. PV use produces no emissions, thus offsetting many potential environmental problems. However, the new PV technologies also bring unfamiliar environment, safety, and health (ES and H) challenges that require innovative solutions. This is a summary of the issues, solutions, and perspectives associated with the use of cadmium in one of the new and important PV technologies: thin-film, cadmium telluride (CdTe) PV, which is being developed and commercialized by several companies including Solar Cells Inc. (Toledo, Ohio), BP Solar (Fairfield, California), and Matsushita (Japan). The principal ES and H issue for thin-film cadmium telluride PV is the potential introduction of cadmium--a toxic heavy metal--into the air or water. The amount of cadmium in thin-film PV, however, is quite small--one nickel cadmium flashlight battery has about as much cadmium (7 g) as a square meter of PV module using current technology--and a typical cordless power tool will have 5--10 batteries. CdTe modules are also very well sealed, limiting the chance of release. Nonetheless, minimizing the amount of cadmium in cadmium telluride modules and preventing the introduction of that cadmium into the environment is a top priority for National Renewable Energy Laboratory researchers and cadmium telluride PV manufacturers

  5. GEOLOGY OF THE FLORENCIA GOLD – TELLURIDE DEPOSIT (CAMAGÜEY, CUBA AND SOME METALLURGICAL CONSIDERATIONS

    Directory of Open Access Journals (Sweden)

    López K Jesús M.

    2006-12-01

    Full Text Available This paper describes the results from a study of the Florencia gold-telluride deposit in Central Cuba, including mineralogical, petrographical, microprobe and chemical analysis. Valuable information is provided for the exploration, mining and processing of gold ores from other nearby deposits with similar characteristics. Results highlight changes in the mineralogical composition of the ores between the north and south sectors of the deposit, as reflected in metallurgical concentrates after beneficiation and flotation of samples from these sectors.
    It is shown that gold deposits of the Cretaceous Volcanic Arc of Cuba largely consist of native gold, telluride and pyrite, where arsenopyrite is almost absent. Traces of lead, zinc and cadmium are present in the periphery of the main ore zones.

  6. Chemical bath deposited zinc sulfide buffer layers for copper indium gallium sulfur-selenide solar cells and device analysis

    International Nuclear Information System (INIS)

    Kundu, Sambhu; Olsen, Larry C.

    2005-01-01

    Cadmium-free copper indium gallium sulfur-selenide (CIGSS) thin film solar cells have been fabricated using chemical bath deposited (CBD) zinc sulfide (ZnS) buffer layers. Shell Solar Industries provided high quality CIGSS absorber layers. The use of CBD-ZnS, which is a higher band gap material than CdS, improved the quantum efficiency of fabricated cells at lower wavelengths, leading to an increase in short circuit current. The best cell to date yielded an active area (0.43 cm 2 ) efficiency of 13.3%. The effect of the ZnS buffer layer thickness on device performance was studied carefully. This paper also presents a discussion of issues relevant to the use of the CBD-ZnS buffer material for improving device performance

  7. Rise time spectroscopy in cadmium telluride detectors

    International Nuclear Information System (INIS)

    Scharager, Claude; Siffert, Paul; Carnet, Bernard; Le Meur, Roger.

    1980-11-01

    By a simultaneous analysis of rise time and pulse amplitude distributions of the signals issued from various cadmium telluride detectors, it is possible to obtain informations about surface and bulk trapping, field distribution within the detectors, as well as charge collection and transport properties. These investigations have been performed on both pure and chlorine doped and materials for various surfaces preparation conditions [fr

  8. Structural Properties of Zinc Oxide Nanorods Grown on Al-Doped Zinc Oxide Seed Layer and Their Applications in Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Kyung Ho Kim

    2014-03-01

    Full Text Available We fabricated zinc oxide (ZnO nanorods (NRs with Al-doped ZnO (AZO seed layers and dye-sensitized solar cells (DSSCs employed the ZnO NRs between a TiO2 photoelectrode and a fluorine-doped SnO2 (FTO electrode. The growth rate of the NRs was strongly dependent on the seed layer conditions, i.e., thickness, Al dopant and annealing temperature. Attaining a large particle size with a high crystallinity of the seed layer was vital to the well-aligned growth of the NRs. However, the growth was less related to the substrate material (glass and FTO coated glass. With optimized ZnO NRs, the DSSCs exhibited remarkably enhanced photovoltaic performance, because of the increase of dye absorption and fast carrier transfer, which, in turn, led to improved efficiency. The cell with the ZnO NRs grown on an AZO seed layer annealed at 350 °C showed a short-circuit current density (JSC of 12.56 mA/cm2, an open-circuit voltage (VOC of 0.70 V, a fill factor (FF of 0.59 and a power conversion efficiency (PCE, η of 5.20% under air mass 1.5 global (AM 1.5G illumination of 100 mW/cm2.

  9. Property elucidation of vacuum-evaporated zinc telluride thin film ...

    Indian Academy of Sciences (India)

    J U Ahamed

    2017-08-31

    Aug 31, 2017 ... method for the deposition of ZnTe thin film as compared to other methods. ... the advantages and disadvantages of different deposition process, it was ... by a spiral resistance heater and the temperature was measured by a ...

  10. Cadium-Zinc-Telluride (CZT) Gamma Ray Spectrometry

    International Nuclear Information System (INIS)

    William Quam

    2001-01-01

    This report describes CZT crystals and their use in large arrays for generation of gamma ray spectra. Laboratory spectra will be shown together with spectra accumulated by various battery powered portable instruments (see Appendix A). One of these portable instruments was specifically constructed to minimize power consumption and yet provide reasonable isotope identification capability. Detailed data will be presented covering gamma energy resolution, gamma peak shapes, system background, and detector efficiency. Nearly all data were taken with very small crystals of CZT; cubes 5 mm on a side. A few spectra will be presented from cylindrical crystals of about the same size (see Appendix A). The small crystal size leads to low counting rates and extended counting times for reliable isotope identification. We have addressed this problem by using arrays of CZT crystals, initially two crystals and, at present, arrays of eight crystals. Data will be shown relating spectral parameters for these two arrays. System MDA is one way of combining resolution, efficiency, and background that will enable direct comparison of various detector types for individual isotope identification. We have calculated the MDA for an early dual crystal array and the current eight crystal array. Data derived from each array will be presented. In addition, it is possible to extrapolate the MDA methodology to much larger arrays. A 32-crystal array is under construction and extrapolations to 256 and 1024 crystals are considered possible. Estimated MDA values for these larger arrays are also presented. Several 8-crystal arrays have been constructed and versions have been incorporated into portable instruments. Descriptions of these small instruments are given covering physical size, weight, and general configuration. These instruments have been tested for shock and temperature effects and data will be presented on the results of these tests. The MDA concept will also allow extrapolation to large source to detector distances. The usual laboratory measurements are done with small sources at 20 to 50 cm ranges. Practical ranges for aerial work will be 50 to 100 meters or greater. These distances will require correction for air attenuation for most of the low energy isotopes. The approximations used in the present note for aerial measurements involve small diameter sources (diameter approximately equal to the altitude), a 1 kt pass, and a planar array with no aircraft attenuation material in the field of view. The array will have a collimator to limit the side-looking sensitivity to enable a more accurate extrapolation from the laboratory data. Large arrays will have significant physical size and weight compared to the small hand-held instruments thus far constructed. We estimate these parameters and extrapolate the power consumption to provide a realistic estimate of a suitable airborne system. In all cases these larger systems are lighter and physically more compact than the usual NaI or high purity Germanium (HPGe) systems used in aerial work. Thus deployment should be simple. The power consumption is much less as well

  11. Impurity states of vanadium in cadmium and zinc tellurides

    International Nuclear Information System (INIS)

    Gnatenko, Yu.P.; Farina, I.A.

    1996-01-01

    Low-temperature optical (4.5 K) and photoelectrical properties of CdTe and ZnTe crystals doped by vanadium are invetigated. The energies of carrier transition to valence and conduction bands, Mott-Habbard energy for 3d 3 -ion vanadium in both crystals are determined. The resonance of the excited 4 T l ( 4 P)-state of V 2+ -ion with the conduction band of CdTe crystal is found. 8 bibl.; 4 figs

  12. Growth of cadmium zinc telluride by liquid phase electroepitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Armour, N.; Dost, S. [Crystal Growth Laboratory, Faculty of Engineering, University of Victoria, Victoria BC, V8W 3P6 (Canada); Sheibani, H. [Department of Industrial Engineering, Alhosn University, Abu Dhabi (United Arab Emirates)

    2006-10-15

    This study was undertaken to examine the feasibility of growing CdZnTe by liquid phase electroepitaxy. Based on our successful LPEE system of GaInAs, a new crucible to grow CdZnTe was developed. The development presented numerous difficulties. The physical properties of CdZnTe make this material very difficult to grow. All components of the system were investigated. Electromigration of the solute across the solution carries species towards the growth interface. In liquid Cd-Zn-Te, the CdTe and ZnTe species remain associated, contrary to the GaInAs system. Experiments showed that LPEE growth of CdZnTe is possible and the electromigration mechanism functions well in the CdZnTe solution. Despite this, other problems remained with the new LPEE system. The preparation of the solution proved difficult without pressurizing the LPEE crucible. Control of the reaction required the use of pre-compounded CdTe and ZnTe. Proper control of the solution saturation is imperative to ensure minimal dissolution of the seed prior to growth initiation and a reasonable growth rate during growth. The solution remained an issue during the duration of growth due to the high vapor pressures of the constituents. Tellurium evaporation during growth could lower solution volume until electrical contact across the solution is broken. Careful preparation of appropriate solution volume was imperative for successful growth. In LPEE, a uniform electric current passage across the growth interface is necessary for uniform and stable growth interface. This requires the design of a uniform contact zone between the bottom graphite electrode and the seed crystal. The contact zone issue was not adequately resolved in this study. However, a number of successful growth runs were achieved despite the electrical contact problems. Results show that the LPEE of growth CdZnTe is feasible. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. Growth of cadmium zinc telluride by liquid phase electroepitaxy

    International Nuclear Information System (INIS)

    Armour, N.; Dost, S.; Sheibani, H.

    2006-01-01

    This study was undertaken to examine the feasibility of growing CdZnTe by liquid phase electroepitaxy. Based on our successful LPEE system of GaInAs, a new crucible to grow CdZnTe was developed. The development presented numerous difficulties. The physical properties of CdZnTe make this material very difficult to grow. All components of the system were investigated. Electromigration of the solute across the solution carries species towards the growth interface. In liquid Cd-Zn-Te, the CdTe and ZnTe species remain associated, contrary to the GaInAs system. Experiments showed that LPEE growth of CdZnTe is possible and the electromigration mechanism functions well in the CdZnTe solution. Despite this, other problems remained with the new LPEE system. The preparation of the solution proved difficult without pressurizing the LPEE crucible. Control of the reaction required the use of pre-compounded CdTe and ZnTe. Proper control of the solution saturation is imperative to ensure minimal dissolution of the seed prior to growth initiation and a reasonable growth rate during growth. The solution remained an issue during the duration of growth due to the high vapor pressures of the constituents. Tellurium evaporation during growth could lower solution volume until electrical contact across the solution is broken. Careful preparation of appropriate solution volume was imperative for successful growth. In LPEE, a uniform electric current passage across the growth interface is necessary for uniform and stable growth interface. This requires the design of a uniform contact zone between the bottom graphite electrode and the seed crystal. The contact zone issue was not adequately resolved in this study. However, a number of successful growth runs were achieved despite the electrical contact problems. Results show that the LPEE of growth CdZnTe is feasible. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  14. Surface Treatment And Protection Method For Cadium Zinc Telluride Crystals

    Science.gov (United States)

    Wright, Gomez W.; James, Ralph B.; Burger, Arnold; Chinn, Douglas A.

    2006-02-21

    A method for treatment of the surface of a CdZnTe (CZT) crystal that provides a native dielectric coating to reduce surface leakage currents and thereby, improve the resolution of instruments incorporating detectors using CZT crystals. A two step process is disclosed, etching the surface of a CZT crystal with a solution of the conventional bromine/methanol etch treatment, and after attachment of electrical contacts, passivating the CZT crystal surface with a solution of 10 w/o NH4F and 10 w/o H2O2 in water.

  15. The Cadmium Zinc Telluride Imager on AstroSat

    Indian Academy of Sciences (India)

    V. Bhalerao

    2017-06-19

    Jun 19, 2017 ... which act as the interface to the satellite. The overall dimensions of ... plate affixed on a side to dissipate heat and provide a cold bias for maintaining ... patterns, with some repeats, were placed in the form of a 4 × 4 matrix to ...

  16. Synthesis of zinc phthalocyanine with large steric hindrance and its photovoltaic performance for dye-sensitized solar cells.

    Science.gov (United States)

    Lin, Li; Peng, Bosi; Shi, Wenye; Guo, Yingying; Li, Renjie

    2015-03-28

    A zinc phthalocyanine (ZnPc) derivative (Zn-tri-PcNc-8) containing tri-benzonaphtho-condensed porphyrazine with one carboxylic and six diphenylphenoxy peripheral substitutions was designed and synthesized as a sensitizer for dye-sensitized solar cells (DSSCs). For the purpose of extending the absorption spectra while minimizing the formation of ZnPc molecular aggregates, bulky 2,6-diphenylphenoxy groups were used as electron donor moieties, and the carboxylic group as an anchoring group to graft the sensitizer onto the semiconductor. It was found that a TiO2-based solar cell sensitized by Zn-tri-PcNc-8 shows a maximum incident photon-to-current conversion efficiency in the red/near-IR light range (650-750 nm), and a solar cell sensitized at near room temperature (30 °C) for 48 h exhibits the best efficiency (3.01%). The efficiency was much higher than that (1.96%) for a solar cell sensitized by its analogue (Zn-tri-PcNc-2) having one carboxyl and three tert-butyl groups without chenodeoxycholic acid (CDCA), indicating that the introduction of six bulky diphenylphenoxy substitutions with large steric hindrance in the ZnPc macrocycle can effectively suppress the molecular aggregates, thus resulting in an improved conversion efficiency. The present results shed light on an effective solution to adjust the ZnPc property via chemical modification such as changing the "push-pull" effect and adding large steric hindrance substituents to further improve the efficiency of the phthalocyanine-sensitized solar cell.

  17. Annealing effect of hybrid solar cells based on poly (3-hexylthiophene) and zinc-oxide nanostructures

    CSIR Research Space (South Africa)

    Motaung, DE

    2013-06-01

    Full Text Available The structural growth and optical and photovoltaic properties of the organic–inorganic hybrid structures of zinc oxide (ZnO)-nanorods/poly-3-hexylthiophene (P3HT) and two variations of organic polymer blends of ZnO/P3HT:C(sub60) fullerene and ZnO/P3...

  18. Self-assembly 2D zinc-phthalocyanine heterojunction: An ideal platform for high efficiency solar cell

    Science.gov (United States)

    Jiang, Xue; Jiang, Zhou; Zhao, Jijun

    2017-12-01

    As an alternative to silicon-based solar cells, organic photovoltaic cells emerge for their easy manufacture, low cost, and light weight but are limited by their less stability, low power conversion efficiencies, and low charge carrier mobilities. Here, we design a series of two-dimensional (2D) organic materials incorporating zinc-phthalocyanine (ZnPc) based building blocks which can inherit their excellent intrinsic properties but overcome those shortcomings. Our first-principles calculation shows that such 2D ZnPc-based materials exhibit excellent thermal stabilities, suitable bandgaps, small effective masses, and good absorption properties. The additional benzene rings and nitrogen atoms incorporated between ZnPc molecules are mainly responsible for the modifications of electronic and optical properties. Moreover, some heterojunction solar cells constructed using those 2D ZnPc monolayers as the donor and acceptor have an appropriate absorber gap and interface band alignment. Among them, a power conversion efficiency up to 14.04% is achieved, which is very promising for the next-generation organic solar cells.

  19. NREL Achieves Solar-Electric Record

    Science.gov (United States)

    Solar-Electric Record New Technology Could Spur Growth in Photovoltaic Panels For more information thin-film panels made from cadmium telluride. Benner said these and other plants may adopt all or part panels. Of the several materials that can be used for thin-film panels, cadmium telluride yields higher

  20. Zinc oxide modified with benzylphosphonic acids as transparent electrodes in regular and inverted organic solar cell structures

    Energy Technology Data Exchange (ETDEWEB)

    Lange, Ilja; Reiter, Sina; Kniepert, Juliane; Piersimoni, Fortunato; Brenner, Thomas; Neher, Dieter, E-mail: neher@uni-potsdam.de [Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Strasse 24-25, 14476 Potsdam (Germany); Pätzel, Michael; Hildebrandt, Jana; Hecht, Stefan [Department of Chemistry and IRIS Adlershof, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489 Berlin (Germany)

    2015-03-16

    An approach is presented to modify the work function of solution-processed sol-gel derived zinc oxide (ZnO) over an exceptionally wide range of more than 2.3 eV. This approach relies on the formation of dense and homogeneous self-assembled monolayers based on phosphonic acids with different dipole moments. This allows us to apply ZnO as charge selective bottom electrodes in either regular or inverted solar cell structures, using poly(3-hexylthiophene):phenyl-C71-butyric acid methyl ester as the active layer. These devices compete with or even surpass the performance of the reference on indium tin oxide/poly(3,4-ethylenedioxythiophene) polystyrene sulfonate. Our findings highlight the potential of properly modified ZnO as electron or hole extracting electrodes in hybrid optoelectronic devices.

  1. Advantages of using amorphous indium zinc oxide films for window layer in Cu(In,Ga)Se{sub 2} solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Warasawa, Moe [Department of Electrical Engineering, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda 278-8510 (Japan); Kaijo, Akira [Idemitsu Kosan Co., Ltd., 1280 Kami-izumi, Sodegaura, 229-0293 (Japan); Sugiyama, Mutsumi, E-mail: mutsumi@rs.noda.tus.ac.jp [Department of Electrical Engineering, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda 278-8510 (Japan)

    2012-01-01

    The advantages of using indium zinc oxide (IZO) films instead of conventional Ga-doped zinc oxide (ZnO:Ga) films for Cu(In,Ga)Se{sub 2} (CIGS) solar cells are described. The electrical properties of IZO are independent of film thickness. IZO films have higher mobility (30-40 cm{sup 2}/Vs) and lower resistivity (4-5 Multiplication-Sign 10{sup -4} {Omega} cm) compared to ZnO:Ga films deposited without intentional heating, because the number of grain boundaries in amorphous IZO films is small. The properties of a CIGS solar cell using IZO at the window layer were better than those obtained using a conventional ZnO:Ga at the window layer; moreover, the properties tended to be independent of thickness. These results indicate that use of IZO as a transparent conducting oxide layer is expected to increase the efficiency of CIGS solar cells.

  2. Occurency and aqueous processing of tellurides from Sonora (Mexico)

    International Nuclear Information System (INIS)

    Aguayo, S.; Perez, E.; Ecinas, M.A.

    1996-01-01

    Tellurium production is limited mainly to that obtained from the treatment of electrolyte muds from copper refineries. however, there are several other sources from which the precious metal tellurides are potentially attractive. This work presents a review of the main localitiesin Sonora (Mexico), where tellurides have been found. In addition, based upon the physical chemistry fundamentals for tellurium and precious metal tellurides, the aqueous extraction and recovery routes are discussed. (Author) 51 refs

  3. Highly transparent and conducting boron doped zinc oxide films for window of Dye Sensitized Solar Cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Vinod, E-mail: vinod.phy@gmail.com [Materials Science Group, Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Department of Physics, Gurukula Kangri University, Haridwar 249404 (India); Singh, R.G. [Department of Electronic Science, Maharaja Agrasen College University of Delhi, New Delhi 110096 (India); Singh, Fouran [Materials Science Group, Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Purohit, L.P. [Department of Physics, Gurukula Kangri University, Haridwar 249404 (India)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Synthesis of Boron doped ZnO (ZnO:B) films. Black-Right-Pointing-Pointer Minimum of resistivity is observed to be 7.9 Multiplication-Sign 10{sup -4} {Omega} cm. Black-Right-Pointing-Pointer Maximum transmittance {approx}91% for 450 Degree-Sign C annealed films. Black-Right-Pointing-Pointer Applicable for window materials in Dye Sensitized Solar Cell. - Abstract: Highly transparent and conducting boron doped zinc oxide (ZnO:B) films grown by sol-gel method are reported. The annealing temperature is varied from 350 to 550 Degree-Sign C and doping concentration of boron is kept fixed for 0.6 at.% for all the films. At low temperature the stress in the films is compressive, which becomes tensile for the films annealed at higher temperature. A minimum resistivity of 7.9 Multiplication-Sign 10{sup -4} {Omega} cm and maximum transmittance of {approx}91% are observed for the film annealed at 450 Degree-Sign C. This could be attributed to minimum stress of films, which is further evident by the evolution of A{sub 1} and defect related Raman modes without any shifting in its position. Such kind of highly transparent and conducting ZnO:B thin film could be used as window material in Dye Sensitized Solar Cell (DSSC).

  4. Pyrolytically grown indium sulfide sensitized zinc oxide nanowires for solar water splitting

    Energy Technology Data Exchange (ETDEWEB)

    Komurcu, Pelin; Can, Emre Kaan; Aydin, Erkan; Semiz, Levent [Micro and Nanotechnology Graduate Program, TOBB University of Economics and Technology, 06560 Ankara (Turkey); Gurol, Alp Eren; Alkan, Fatma Merve [Department of Materials Science and Nanotechnology Engineering, TOBB University of Economics and Technology, 06560 Ankara (Turkey); Sankir, Mehmet; Sankir, Nurdan Demirci [Micro and Nanotechnology Graduate Program, TOBB University of Economics and Technology, 06560 Ankara (Turkey); Department of Materials Science and Nanotechnology Engineering, TOBB University of Economics and Technology, 06560 Ankara (Turkey)

    2015-11-15

    Zinc oxide (ZnO) nanowires, sensitized with spray pyrolyzed indium sulfide, were obtained by chemical bath deposition. The XRD analysis indicated dominant evolution of hexagonal ZnO phase. Significant gain in photoelectrochemical current using ZnO nanowires is largely accountable to enhancement of the visible light absorption and the formation of heterostructure. The maximum photoconversion efficiency of 2.77% was calculated for the indium sulfide sensitized ZnO nanowire photoelectrodes. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Nanostructuring on zinc phthalocyanine thin films for single-junction organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhary, Dhirendra K.; Kumar, Lokendra, E-mail: lokendrakr@allduniv.ac.in [Department of Physics, University of Allahabad, Allahabad-211 002 (India)

    2016-05-23

    Vertically aligned and random oriented crystalline molecular nanorods of organic semiconducting Zinc Phthalocyanine (ZnPc) have been grown on ITO coated glass substrate using solvent volatilization method. Interesting changes in surface morphology were observed under different solvent treatment. Vertically aligned nanorods of ZnPc thin film were observed in the films treated with acetone, where as the random oriented nanorods were observed in the films treated with chloroform. The X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) have been used for characterization of nanostructures. The optical properties of the nanorods have been investigated by UV-Vis. absorption spectroscopy.

  6. Stability of zinc phthalocyanine and fullerene C{sub 60} organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Lessmann, Rudolf

    2010-05-10

    Organic solar cells promise electricity generation at very low cost, and higher installation flexibility as compared to inorganic solar cells. The lower cost is achieved by cheaper semiconductors and easier manufacturing processes. The flexibility is naturally given by these ultra-thin, amorphous layers. Also the power conversion efficiency can be high enough for many applications. The organic molecules have to withstand the constant excitation by photons, transport of energy in form of excitons and charge. A small but significant amount of these photons has energy over the absorption gap, the excess of energy must be released without breaking the molecular bonds. In consequence, the solar cells can also heat up to temperatures at above 80 C. The objective of this work is to answer the question if the small molecules organic solar cells can be stable enough to operate under a very long time. The stability of organic doped layers in an organic solar cell is also addressed. This work starts with a general introduction followed by the description of the experimental procedures. The aging experiments of the solar cell were done with a self developed equipment. The fabrication of this equipment (a set of measurement boxes) was necessary to maintain the conditions, under which a solar cell can be aged, as constant as possible. The measurement boxes were used to control the electrical load of the cell, its temperature, the illumination intensity, and its electric connection to the I vs. V measurement equipment. A software package was also developed to control the equipment and to facilitate the work and visualization of the high volume of collected data. The model solar cells chosen for the aging experiments were donor-acceptor heterojunctions devices formed with the well-known materials C{sub 60} and ZnPc. Two basic different structures were analyzed, because they offered reasonable performance and potentially long lifetime: the flat heterojunction (FHJ) and the mixed

  7. Natively textured surface hydrogenated gallium-doped zinc oxide transparent conductive thin films with buffer layers for solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xin-liang, E-mail: cxlruzhou@163.com; Wang, Fei; Geng, Xin-hua; Huang, Qian; Zhao, Ying; Zhang, Xiao-dan

    2013-09-02

    Natively textured surface hydrogenated gallium-doped zinc oxide (HGZO) thin films have been deposited via magnetron sputtering on glass substrates. These natively textured HGZO thin films exhibit rough pyramid-like textured surface, high optical transmittances in the visible and near infrared region and excellent electrical properties. The experiment results indicate that tungsten-doped indium oxide (In{sub 2}O{sub 3}:W, IWO) buffer layers can effectively improve the surface roughness and enhance the light scattering ability of HGZO thin films. The root-mean-square roughness of HGZO, IWO (10 nm)/HGZO and IWO (30 nm)/HGZO thin films are 28, 44 and 47 nm, respectively. The haze values at the wavelength of 550 nm increase from 7.0% of HGZO thin film without buffer layer to 18.37% of IWO (10 nm)/HGZO thin film. The optimized IWO (10 nm)/HGZO exhibits a high optical transmittance of 82.18% in the visible and near infrared region (λ ∼ 400–1100 nm) and excellent electrical properties with a relatively low sheet resistance of 3.6 Ω/□ and the resistivity of 6.21 × 10{sup −4} Ωcm. - Highlights: • Textured hydrogenated gallium-doped zinc oxide (HGZO) films were developed. • Tungsten-doped indium oxide (IWO) buffer layers were applied for the HGZO films. • Light-scattering ability of the HGZO films can be improved through buffer layers. • Low sheet resistance and high haze were obtained for the IWO(10 nm)/HGZO film. • The IWO/HGZO films are promising transparent conductive layers for solar cells.

  8. Preparation of Zinc Oxide (ZnO) Thin Film as Transparent Conductive Oxide (TCO) from Zinc Complex Compound on Thin Film Solar Cells: A Study of O2 Effect on Annealing Process

    Science.gov (United States)

    Muslih, E. Y.; Kim, K. H.

    2017-07-01

    Zinc oxide (ZnO) thin film as a transparent conductive oxide (TCO) for thin film solar cell application was successfully prepared through two step preparations which consisted of deposition by spin coating at 2000 rpm for 10 second and followed by annealing at 500 °C for 2 hours under O2 and ambient atmosphere. Zinc acetate dehydrate was used as a precursor which dissolved in ethanol and acetone (1:1 mol) mixture in order to make a zinc complex compound. In this work, we reported the O2 effect, reaction mechanism, structure, morphology, optical and electrical properties. ZnO thin film in this work shows a single phase of wurtzite, with n-type semiconductor and has band gap, carrier concentration, mobility, and resistivity as 3.18 eV, 1.21 × 10-19cm3, 11 cm2/Vs, 2.35 × 10-3 Ωcm respectively which is suitable for TCO at thin film solar cell.

  9. Tellurium self-diffusion and point defects in lead telluride

    International Nuclear Information System (INIS)

    Simirskij, Yu.N.; Firsova, L.P.

    1982-01-01

    Method of radioactive indicators was used to determine factors of tellurium self-diffusion in lead telluride with different deviation of the composition from stoichiometric in the range of enrichment by tellurium. It was found that at 973 K factors of tellurium self-diffusion in lead telluride depend slightly on the vapor pressure of tellurium equilibrium with solid phase

  10. All-inorganic inverse perovskite solar cells using zinc oxide nanocolloids on spin coated perovskite layer

    Science.gov (United States)

    Shibayama, Naoyuki; Kanda, Hiroyuki; Yusa, Shin-ichi; Fukumoto, Shota; Baranwal, Ajay K.; Segawa, Hiroshi; Miyasaka, Tsutomu; Ito, Seigo

    2017-07-01

    We confirmed the influence of ZnO nanoparticle size and residual water on performance of all inorganic perovskite solar cells. By decreasing the size of the ZnO nanoparticles, the short-circuit current density ( Jsc) and open circuit photovoltage ( Voc) values are increased and the conversion efficiency is improved. Although the Voc value is not affected by the influence of residual water in the solution for preparing the ZnO layer, the Jsc value drops greatly. As a result, it was found that it is important to use the oxide nanoparticles with a small particle diameter and to reduce the water content in the oxide forming material in order to manufacture a highly efficient all inorganic perovskite solar cells.

  11. Boron-doped zinc oxide thin films for large-area solar cells grown by metal organic chemical vapor deposition

    International Nuclear Information System (INIS)

    Chen, X.L.; Xu, B.H.; Xue, J.M.; Zhao, Y.; Wei, C.C.; Sun, J.; Wang, Y.; Zhang, X.D.; Geng, X.H.

    2007-01-01

    Boron-doped zinc oxide (ZnO:B) films were grown by metal organic chemical vapor deposition using diethylzinc (DEZn), and H 2 O as reactant gases and diborane (B 2 H 6 ) as an n-type dopant gas. The structural, electrical and optical properties of ZnO films doped at different B 2 H 6 flow rates were investigated. X-ray diffraction spectra and scanning electron microscopy images indicate that boron-doping plays an important role on the microstructure of ZnO films, which induced textured morphology. With optimized conditions, low sheet resistance (∼ 30 Ω/□), high transparency (> 85% in the visible light and infrared range) and high mobility (17.8 cm 2 V -1 s -1 ) were obtained for 700-nm ZnO:B films deposited on 20 cm x 20 cm glass substrates at the temperature of 443 K. After long-term exposure in air, the ZnO:B films also showed a better electrical stability than the un-doped samples. With the application of ZnO:B/Al back contacts, the short circuit current density was effectively enhanced by about 3 mA/cm 2 for a small area a-Si:H cell and a high efficiency of 9.1% was obtained for a large-area (20 cm x 20 cm) a-Si solar module

  12. Double-layer indium doped zinc oxide for silicon thin-film solar cell prepared by ultrasonic spray pyrolysis

    International Nuclear Information System (INIS)

    Jiao Bao-Chen; Zhang Xiao-Dan; Wei Chang-Chun; Sun Jian; Ni Jian; Zhao Ying

    2011-01-01

    Indium doped zinc oxide (ZnO:In) thin films were prepared by ultrasonic spray pyrolysis on corning eagle 2000 glass substrate. 1 and 2 at.% indium doped single-layer ZnO:In thin films with different amounts of acetic acid added in the initial solution were fabricated. The 1 at.% indium doped single-layers have triangle grains. The 2 at.% indium doped single-layer with 0.18 acetic acid adding has the resistivity of 6.82×10 −3 Ω·cm and particle grains. The double-layers structure is designed to fabricate the ZnO:In thin film with low resistivity (2.58×10 −3 Ω·cm) and good surface morphology. It is found that the surface morphology of the double-layer ZnO:In film strongly depends on the substrate-layer, and the second-layer plays a large part in the resistivity of the double-layer ZnO:In thin film. Both total and direct transmittances of the double-layer ZnO:In film are above 80% in the visible light region. Single junction a-Si:H solar cell based on the double-layer ZnO:In as front electrode is also investigated. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  13. Low temperature deposition of bifacial CIGS solar cells on Al-doped Zinc Oxide back contacts

    Energy Technology Data Exchange (ETDEWEB)

    Cavallari, Nicholas, E-mail: nicholas.cavallari@imem.cnr.it [IMEM-CNR, Parco Area delle Scienze 37/a, 43124 Parma (Italy); Department of Mathematical, Physical and Computer Sciences, University of Parma, Parco Area delle Scienze 7/a, 43124 Parma (Italy); Pattini, Francesco; Rampino, Stefano; Annoni, Filippo [IMEM-CNR, Parco Area delle Scienze 37/a, 43124 Parma (Italy); Barozzi, Mario [FBK—CMM—Micro Nano Facility, Via Sommarive 18, 38123 Trento (Italy); Bronzoni, Matteo; Gilioli, Edmondo; Gombia, Enos [IMEM-CNR, Parco Area delle Scienze 37/a, 43124 Parma (Italy); Maragliano, Carlo [Solar Bankers LLC, Phoenix, AZ (United States); Mazzer, Massimo [IMEM-CNR, Parco Area delle Scienze 37/a, 43124 Parma (Italy); Pepponi, Giancarlo [FBK—CMM—Micro Nano Facility, Via Sommarive 18, 38123 Trento (Italy); Spaggiari, Giulia; Fornari, Roberto [IMEM-CNR, Parco Area delle Scienze 37/a, 43124 Parma (Italy); Department of Mathematical, Physical and Computer Sciences, University of Parma, Parco Area delle Scienze 7/a, 43124 Parma (Italy)

    2017-08-01

    Highlights: • AZO and CIGS were deposited by Low-Temperature Pulsed Electron Deposition (LT-PED). • CIGS/AZO contacts with ohmic behavior and resistance of 1.07 Ω cm{sup 2} were fabricated. • LT-PED deposition of AZO and CIGS prevents formation of Ga{sub 2}O{sub 3} interlayer. • CIGS-based bifacial solar cells with AZO back contact were realized. • Front PV efficiency of 9.3% and equivalent bifacial efficiency of 11.6% were achieved. - Abstract: We report on the fabrication and characterization of Cu(In,Ga)Se{sub 2} (CIGS)-based thin film bifacial solar cells using Al-doped ZnO (AZO) as cost-effective and non-toxic transparent back contact. We show that, by depositing both CIGS and AZO by Low Temperature Pulsed Electron Deposition at a maximum temperature of 250 °C, a good ohmic contact is formed between the two layers and good quality solar cells can be fabricated as a result. Photovoltaic efficiencies as high as 9.3% (front illumination), 5.1% (backside illumination) and 11.6% (bifacial illumination) have been obtained so far. These values are remarkably higher than those previously reported in the literature. We demonstrate that this improvement is ascribed to the low-temperature deposition process that avoids the formation of Ga{sub 2}O{sub 3} at the CIGS/AZO interface and favours the formation of a low-resistivity contact in agreement with device simulations.

  14. Highly transparent vanadium oxide-graded indium zinc oxide electrodes for flexible organic solar cells

    International Nuclear Information System (INIS)

    Ko, Eun-Hye; Kim, Han-Ki

    2016-01-01

    We investigated characteristics of amorphous V_2O_5-graded InZnO (IZO) films to use as a flexible anode for flexible organic solar cells (FOSCs). Graded sputtering of the V_2O_5 layer on the IZO layer produced V_2O_5-graded IZO anodes (VGIZO) with a sheet resistance of 42.14 Ω/square, a resistivity of 6.32 × 10"−"4 Ω cm, and an optical transmittance of 82.15%, as well as good mechanical flexibility. In addition, the VGIZO electrode showed a greater work function of 5.2 eV than that (4.9 eV) of an IZO anode, which is beneficial for hole extraction from an organic active layer. Due to the higher work function of the VGIZO electrodes, FOSCs fabricated on the flexible VGIZO anode exhibited a higher power conversion efficiency 2.753% than that of FOSCs on the IZO anode. This indicates that the V_2O_5 graded sputtering is a promising technique to increase the work function of the IZO anode without change in sheet resistance and transmittance. - Highlights: • Transparent and flexible V_2O_5 graded IZO (VGIZO) electrodes. • High work function of VGIZO electrodes • The VGIZO film is a promising flexible anode for flexible organic solar cells.

  15. Investigation on the Tunable-Length Zinc Oxide Nanowire Arrays for Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Shou-Yi Kuo

    2014-01-01

    Full Text Available We had successfully fabricated ZnO-based nanowires by vapor transport method in the furnace tube. ZnO nanowire arrays grown in 600°C for 30 minutes, 60 minutes, 90 minutes, and 120 minutes had applied to the dye-sensitized solar cells. The dye loading is proportional to the total equivalent surface area of ZnO nanowire arrays in the cells and plays an important role in improving power conversion efficiency. The highest efficiency was observed in DSSC sample with ZnO nanowires grown for 90 minutes, which had the largest equivalent surface area and also the highest dye loading. According to our experimental results, the enhancement in power conversion efficiency is attributed to the higher light harvesting and reduction of carrier recombination. In addition, ZnO nanowires also contribute to the photocurrent in the UV region.

  16. Zinc Sulfide Buffer Layer for CIGS Solar Cells Prepared by Chemical Bath Deposition

    Directory of Open Access Journals (Sweden)

    Rui-Wei You

    2016-11-01

    Full Text Available In this study, ZnS thin films were successfully synthesized by chemical bath deposition (CBD with starting materials of NH2-NH2, SC(NH22, and ZnSO4‧7H2O. ZnS thin films were deposited with different time on glass substrates by CBD at 80oC and pH=9. Based on X-ray diffraction (XRD patterns, it is found that the ZnS thin films exhibit cubic polycrystalline phase. It was found that the optimum deposition time is 90 min for preparing ZnS thin film that is suitable as buffer layer for CuIn1-xGaxSe2 solar cells. The thin film deposited for 90 min has high transmittance up to 80% in the spectra range from 350 nm to 800 nm, and the optical band gap is about 3.59 eV.

  17. Theoretical study of bismuth-doped cadmium telluride

    Science.gov (United States)

    Menendez-Proupin, E.; Rios-Gonzalez, J. A.; Pena, J. L.

    Cadmium telluride heavily doped with bismuth has been proposed as an absorber with an intermediate band for solar cells. Increase in the photocurrent has been shown recently, although the overall cell efficiency has not improved. In this work, we study the electronic structure and the formation energies of the defects associated to bismuth impurities. We have performed electronic structure calculations within generalized density functional theory, using the exchange-correlation functional HSE(w) , where the range-separation parameter w has been tuned to reproduce the CdTe bandgap. Improving upon previous reports, we have included the spin-orbit interaction, which modifies the structure of the valence band and the energy levels of bismuth. We have found that interstitial Bi (Bii) tends to occupy Cd vacancies, cadmium substitution (BiCd) creates single donor level, while tellurium substitution (BiTe) is a shallow single acceptor. We investigate the interaction between these point defects and how can they be combined to create a partially filled intermediate band. Supported by FONDECYT Grant 1130437, CONACYT-SENER SUSTENTABILIDAD ENERGETICA/project CeMIE-Sol PY-207450/25 and PY-207450/26. JARG acknowledges CONACYT fellowship for research visit. Powered@NLHPC (ECM-02).

  18. Mercury telluride as a zero-gap semiconductor

    International Nuclear Information System (INIS)

    Berchenko, N.N.; Pashkovskij, M.V.

    1976-01-01

    The paper presents a review of main properties of mercury telluride which is a representative of a new class of substances - gapless semiconductors. The causes leading to the appearance of a gapless state in mercury chalcogenides are considered; it is demonstrated that the main role in the formation of the inverse band structure belongs to relativistic corrections. The specific properties of mercury telluride are associated with the zero forbidden band, p-like nature of electron states of the conduction band and its nonparabolicity, resonance states of impurities and anomalies of dielectric permittivity. Conditions of forbidden band appearing in mercury telluride under the effect external factors are analyzed

  19. Potassium-doped zinc oxide as photocathode material in dye-sensitized solar cells.

    Science.gov (United States)

    Bai, Jie; Xu, Xiaobao; Xu, Ling; Cui, Jin; Huang, Dekang; Chen, Wei; Cheng, Yibing; Shen, Yan; Wang, Mingkui

    2013-04-01

    ZnO nanoparticles are doped with K and applied in p-type dye-sensitized solar cells (DSCs). The microstructure and dynamics of hole transportation and recombination are investigated. The morphology of the K-doped ZnO nanoparticles shows a homogeneous distribution with sizes in the range 30-40 nm. When applied in p-type DSCs in combination with C343 as sensitizer, the K-doped ZnO nanoparticles achieve a photovoltaic power conversion efficiency of 0.012 % at full-intensity sunlight. A further study on the device by transient photovoltage/photocurrent decay measurements shows that the K-doped ZnO nanoparticles have an appreciable hole diffusion coefficient (ca. 10(-6) cm(2) s(-1) ). Compared to the widely used p-type NiO nanoparticles, this advantage is crucial for further improving the efficiency of p-type DSCs. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Efficient dye-sensitized solar cells from mesoporous zinc oxide nanostructures sensitized by N719 dye

    Science.gov (United States)

    Kumara, G. R. A.; Deshapriya, U.; Ranasinghe, C. S. K.; Jayaweera, E. N.; Rajapakse, R. M. G.

    2018-03-01

    Dye-sensitized solar cells (DSCs) have attracted a great deal of attention due to their low-cost and high power conversion efficiencies. They usually utilize an interconnected nanoparticle layer of TiO2 as the electron transport medium. From the fundamental point of view, faster mobility of electrons in ZnO is expected to contribute to better performance in DSCs than TiO2, though the actual practical situation is quite the opposite. In this research, we addressed this problem by first applying a dense layer of ZnO on FTO followed by a mesoporous layer of interconnected ZnO nanoparticle layer, both were prepared by spray pyrolysis technique. The best cell shows a power conversion efficiency of 5.2% when the mesoporous layer thickness is 14 μm and the concentration of the N719 dye in dye coating solution is 0.3 mM, while a cell without a dense layer shows 4.2% under identical conditions. The surface concentration of dye adsorbed in the cell with a dense layer and that without a dense layer are 5.00 × 10‑7 and 3.34 × 10‑7 mol/cm2, respectively. The cell with the dense layer has an electron lifetime of 54.81 ms whereas that without the dense layer is 11.08 ms. As such, the presence of the dense layer improves DSC characteristics of ZnO-based DSCs.

  1. Nanostructured zinc oxide photoelectrodes by green routes M-SILAR and electrodeposition for dye sensitized solar cell

    Science.gov (United States)

    Gaikwad, M. A.; Suryawanshi, M. P.; Maldar, P. S.; Dongale, T. D.; Moholkar, A. V.

    2018-04-01

    Surfactant-free, ultrasound assisted modified successive ionic layer adsorption and reaction (M-SILAR) method and home-made microcontroller based low-cost potentiostat system are employed to prepare zinc oxide (ZnO) nanostructure based thin films. The comparison between physicochemical as well as photoelectrochemical (PEC) properties of the nanostructures prepared via two different template free, simplistic and cost-effective green routes have been discussed in detail. X-ray diffraction and Raman analysis confirm the formation of phase pure ZnO with the hexagonal crystal structure. Surface morphology significantly affects the physicochemical as well as PEC properties of ZnO thin films. Nanorods (NRs) and nanosheets (NSs) based ZnO thin films sensitized with N3 dye have been directly used as photoelectrodes in the dye-sensitized solar cell (DSSC). The power conversion efficiency (PCE) of 0.59% is achieved with Jsc of 4.04 mA/cm2 and Voc of 0.44 V for the DSSC in which the M-SILAR deposited 1-D ZnO NRs based thin film is used as the photoanode. While relatively less PCE of 0.29% with Jsc of 2.53 mA/cm2 and Voc of 0.36 V is obtained for DSSC prepared using electrodeposited 2-D ZnO NSs. In the NSs like 2-D surface morphology, the presence of multiple grain boundaries are acted as traps for the diffusing electrons, which reduces the electron mobility through it.

  2. A Zinc Porphyrin Sensitizer Modified with Donor and Acceptor Groups for Dye-ensitized Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Lee, See Woo; Sarker, K. Ashis; Hong, Jong Dal [Incheon National University, Incheon (Korea, Republic of)

    2014-09-15

    In this article, we have designed and synthesized a novel donor-π-acceptor (D-π-A) type porphyrin-based sensitizer (denoted UI-5), in which a carboxyl anchoring group and a 9,9-dimethyl fluorene were introduced at the meso-positions of porphyrin ring via phenylethynyl and ethynyl bridging units, respectively. Long alkoxy chains in ortho-positions of the phenyls were supposed to reduce the degree of dye aggregation, which tends to affect electron injection yield in a photovoltaic cell. The cyclic voltammetry was employed to determine the band gap of UI-5 to be 1.41 eV based on the HOMO and LUMO energy levels, which were estimated by the onset oxidation and reduction potentials. The incident monochromatic photon-to-current conversion efficiency of the UI-5 DSSC assembled with double-layer (20 nm-sized TiO{sub 2}/400 nm-sized TiO{sub 2}) film electrodes appeared lower upon overall ranges of the excitation wavelengths, but exhibited a higher value over the NIR ranges (λ = 650-700 nm) compared to the common reference sensitizer N719. The UI-5-sensitized cell yielded a relatively poor device performance with an overall conversion efficiency of 0.74% with a short circuit photocurrent density of 3.05 mA/cm2, an open circuit voltage of 0.54 mV and a fill factor of 0.44 under the standard global air mass (AM 1.5) solar conditions. However, our report about the synthesis and the photovoltaic characteristics of a porphyrin-based sensitizer in a D-π-A structure demonstrated a significant complex relationship between the sensitizer structure and the cell performance.

  3. Porphyrin Dye-Sensitized Zinc Oxide Aggregated Anodes for Use in Solar Cells

    Directory of Open Access Journals (Sweden)

    Yu-Kai Syu

    2016-08-01

    Full Text Available Porphyrin YD2-o-C8-based dyes were employed to sensitize room-temperature (RT chemical-assembled ZnO aggregated anodes for use in dye-sensitized solar cells (DSSCs. To reduce the acidity of the YD2-o-C8 dye solution, the proton in the carboxyl group of a porphyrin dye was replaced with tetrabuthyl ammonium (TBA+ in this work. The short-circuit current density (Jsc of the YD2-o-C8-TBA-sensitized ZnO DSSCs is higher than that of the YD2-o-C8-sensitized cells, resulting in the improvement of the efficiency of the YD2-o-C8-based ZnO DSSCs. With an appropriate incorporation of chenodeoxycholic acid (CDCA as coadsorbate, the Jsc and efficiency of the YD2-o-C8-TBA-sensitized ZnO DSSC are enhanced due to the improvement of the incident-photon-to-current efficiency (IPCE values in the wavelength range of 400–450 nm. Moreover, a considerable increase in Jsc is achieved by the addition of a light scattering layer in the YD2-o-C8-TBA-sensitized ZnO photoanodes. Significant IPCE enhancement in the range 475–600 nm is not attainable by tuning the YD2-o-C8-TBA sensitization processes for the anodes without light scattering layers. Using the RT chemical-assembled ZnO aggregated anode with a light scattering layer, an efficiency of 3.43% was achieved in the YD2-o-C8-TBA-sensitized ZnO DSSC.

  4. Zinc tin oxide as high-temperature stable recombination layer for mesoscopic perovskite/silicon monolithic tandem solar cells

    KAUST Repository

    Werner, Jé ré mie; Walter, Arnaud; Rucavado, Esteban; Moon, Soo Jin; Sacchetto, Davide; Rienaecker, Michael; Peibst, Robby; Brendel, Rolf; Niquille, Xavier; De Wolf, Stefaan; Lö per, Philipp; Morales-Masis, Monica; Nicolay, Sylvain; Niesen, Bjoern; Ballif, Christophe

    2016-01-01

    the concept, we fabricate monolithic tandem cells with mesoscopic top cell with up to 16% efficiency. We then investigate the effect of zinc tin oxide layer thickness variation, showing a strong influence on the optical interference pattern within the tandem

  5. Boron-doped zinc oxide thin films grown by metal organic chemical vapor deposition for bifacial a-Si:H/c-Si heterojunction solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Xiangbin, E-mail: eexbzeng@mail.hust.edu.cn; Wen, Xixing; Sun, Xiaohu; Liao, Wugang; Wen, Yangyang

    2016-04-30

    Boron-doped zinc oxide (BZO) films were grown by metal organic chemical vapor deposition. The influence of B{sub 2}H{sub 6} flow rate and substrate temperature on the microstructure, optical, and electrical properties of BZO films was investigated by X-ray diffraction spectrum, scanning electron microscope, optical transmittance spectrum, and Hall measurements. The BZO films with optical transmittance above 85% in the visible and infrared light range, resistivity of 0.9–1.0 × 10{sup −3} Ω cm, mobility of 16.5–25.5 cm{sup 2}/Vs, and carrier concentration of 2.2–2.7 × 10{sup 20} cm{sup −3} were deposited under optimized conditions. The optimum BZO films were applied on the bifacial BZO/p-type a-Si:H/i-type a-Si:H/n-type c-Si/i-type a-Si:H/n{sup +}-type a-Si:H/BZO heterojunction solar cell as both front and back transparent electrodes. Meanwhile, the bifacial heterojunction solar cell with indium tin oxide (ITO) as both front and back transparent electrodes was fabricated. The efficiencies of 17.788% (open-circuit voltage: 0.628 V, short-circuit current density: 41.756 mA/cm{sup 2} and fill factor: 0.678) and 16.443% (open-circuit voltage: 0.590 V, short-circuit current density: 36.515 mA/cm{sup 2} and fill factor: 0.762) were obtained on the a-Si/c-Si heterojunction solar cell with BZO and ITO transparent electrodes, respectively. - Highlights: • Boron-doped zinc oxide films with low resistivity were fabricated. • The boron-doped zinc oxide films have the high transmittance. • B-doped ZnO film was applied in a-Si:H/c-Si solar cell as transparent electrodes. • The a-Si:H/c-Si solar cell with efficiency of 17.788% was obtained.

  6. Boron-doped zinc oxide thin films grown by metal organic chemical vapor deposition for bifacial a-Si:H/c-Si heterojunction solar cells

    International Nuclear Information System (INIS)

    Zeng, Xiangbin; Wen, Xixing; Sun, Xiaohu; Liao, Wugang; Wen, Yangyang

    2016-01-01

    Boron-doped zinc oxide (BZO) films were grown by metal organic chemical vapor deposition. The influence of B_2H_6 flow rate and substrate temperature on the microstructure, optical, and electrical properties of BZO films was investigated by X-ray diffraction spectrum, scanning electron microscope, optical transmittance spectrum, and Hall measurements. The BZO films with optical transmittance above 85% in the visible and infrared light range, resistivity of 0.9–1.0 × 10"−"3 Ω cm, mobility of 16.5–25.5 cm"2/Vs, and carrier concentration of 2.2–2.7 × 10"2"0 cm"−"3 were deposited under optimized conditions. The optimum BZO films were applied on the bifacial BZO/p-type a-Si:H/i-type a-Si:H/n-type c-Si/i-type a-Si:H/n"+-type a-Si:H/BZO heterojunction solar cell as both front and back transparent electrodes. Meanwhile, the bifacial heterojunction solar cell with indium tin oxide (ITO) as both front and back transparent electrodes was fabricated. The efficiencies of 17.788% (open-circuit voltage: 0.628 V, short-circuit current density: 41.756 mA/cm"2 and fill factor: 0.678) and 16.443% (open-circuit voltage: 0.590 V, short-circuit current density: 36.515 mA/cm"2 and fill factor: 0.762) were obtained on the a-Si/c-Si heterojunction solar cell with BZO and ITO transparent electrodes, respectively. - Highlights: • Boron-doped zinc oxide films with low resistivity were fabricated. • The boron-doped zinc oxide films have the high transmittance. • B-doped ZnO film was applied in a-Si:H/c-Si solar cell as transparent electrodes. • The a-Si:H/c-Si solar cell with efficiency of 17.788% was obtained.

  7. Studies of antimony telluride and copper telluride films electrodeposition from choline chloride containing ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Catrangiu, Adriana-Simona; Sin, Ion [Department of Inorganic Chemistry, Physical Chemistry and Electrochemistry, POLITEHNICA University of Bucharest, Calea Grivitei 132, Bucharest (Romania); Prioteasa, Paula [INCDIE ICPE-Advanced Research, Splaiul Unirii 313, Bucharest (Romania); Cotarta, Adina [Department of Inorganic Chemistry, Physical Chemistry and Electrochemistry, POLITEHNICA University of Bucharest, Calea Grivitei 132, Bucharest (Romania); Cojocaru, Anca, E-mail: a_cojocaru@chim.upb.ro [Department of Inorganic Chemistry, Physical Chemistry and Electrochemistry, POLITEHNICA University of Bucharest, Calea Grivitei 132, Bucharest (Romania); Anicai, Liana [Center of Surface Science and Nanotechnology, University POLITEHNICA of Bucharest, Splaiul Independentei 313, Bucharest (Romania); Visan, Teodor [Department of Inorganic Chemistry, Physical Chemistry and Electrochemistry, POLITEHNICA University of Bucharest, Calea Grivitei 132, Bucharest (Romania)

    2016-07-29

    Cyclic voltammetry and electrochemical impedance spectroscopy were used to investigate the deposition of antimony telluride or copper telluride from ionic liquid consisting in mixture of choline chloride with oxalic acid. In addition, the cathodic process during copper telluride formation was studied in the mixture of choline chloride with ethylene glycol. The results indicate that the Pt electrode is first covered with a Te layer, and then the more negative polarisation leads to the deposition of Sb{sub x}Te{sub y} or Cu{sub x}Te{sub y} semiconductor compounds. Thin films were deposited on copper and carbon steel at 60–70 °C and were characterised by scanning electron microscopy, energy X-ray dispersive spectroscopy (EDS), and X-ray diffraction (XRD). Their stoichiometry depends on the bath composition and applied potential. EDS and XRD patterns indicate the possible synthesis of stoichiometric Sb{sub 2}Te{sub 3} phase and Cu{sub 2}Te, Cu{sub 5}Te{sub 3}, and Cu{sub 2.8}Te{sub 2} phases, respectively, by controlling the ratio of ion concentrations in ionic liquid electrolytes and deposition potential. - Highlights: • Sb{sub x}Te{sub y} and Cu{sub x}Te{sub y} films electrodeposited from choline-chloride-based ionic liquids. • The stoichiometry of film depends on the bath composition and deposition potential. • Sb{sub 2}Te{sub 3}, Cu{sub 2}Te, Cu{sub 5}Te{sub 3}, Cu{sub 2.8}Te{sub 2} phases were identified in X-ray diffraction patterns.

  8. Efficient indium-tin-oxide free inverted organic solar cells based on aluminum-doped zinc oxide cathode and low-temperature aqueous solution processed zinc oxide electron extraction layer

    International Nuclear Information System (INIS)

    Chen, Dazheng; Zhang, Chunfu; Wang, Zhizhe; Zhang, Jincheng; Tang, Shi; Wei, Wei; Sun, Li; Hao, Yue

    2014-01-01

    Indium-tin-oxide (ITO) free inverted organic solar cells (IOSCs) based on aluminum-doped zinc oxide (AZO) cathode, low-temperature aqueous solution processed zinc oxide (ZnO) electron extraction layer, and poly(3-hexylthiophene-2, 5-diyl):[6, 6]-phenyl C 61 butyric acid methyl ester blend were realized in this work. The resulted IOSC with ZnO annealed at 150 °C shows the superior power conversion efficiency (PCE) of 3.01%, if decreasing the ZnO annealing temperature to 100 °C, the obtained IOSC also shows a PCE of 2.76%, and no light soaking issue is observed. It is found that this ZnO film not only acts as an effective buffer layer but also slightly improves the optical transmittance of AZO substrates. Further, despite the relatively inferior air-stability, these un-encapsulated AZO/ZnO IOSCs show comparable PCEs to the referenced ITO/ZnO IOSCs, which demonstrates that the AZO cathode is a potential alternative to ITO in IOSCs. Meanwhile, this simple ZnO process is compatible with large area deposition and plastic substrates, and is promising to be widely used in IOSCs and other relative fields.

  9. Synthesis and evaluation of lead telluride/bismuth antimony telluride nanocomposites for thermoelectric applications

    Science.gov (United States)

    Ganguly, Shreyashi; Zhou, Chen; Morelli, Donald; Sakamoto, Jeffrey; Uher, Ctirad; Brock, Stephanie L.

    2011-12-01

    Heterogeneous nanocomposites of p-type bismuth antimony telluride (Bi 2- xSb xTe 3) with lead telluride (PbTe) nanoinclusions have been prepared by an incipient wetness impregnation approach. The Seebeck coefficient, electrical resistivity, thermal conductivity and Hall coefficient were measured from 80 to 380 K in order to investigate the influence of PbTe nanoparticles on the thermoelectric performance of nanocomposites. The Seebeck coefficients and electrical resistivities of nanocomposites decrease with increasing PbTe nanoparticle concentration due to an increased hole concentration. The lattice thermal conductivity decreases with the addition of PbTe nanoparticles but the total thermal conductivity increases due to the increased electronic thermal conductivity. We conclude that the presence of nanosized PbTe in the bulk Bi 2- xSb xTe 3 matrix results in a collateral doping effect, which dominates transport properties. This study underscores the need for immiscible systems to achieve the decreased thermal transport properties possible from nanostructuring without compromising the electronic properties.

  10. Electrochemical Deposition of Lanthanum Telluride Thin Films and Nanowires

    Science.gov (United States)

    Chi, Su (Ike); Farias, Stephen; Cammarata, Robert

    2013-03-01

    Tellurium alloys are characterized by their high performance thermoelectric properties and recent research has shown nanostructured tellurium alloys display even greater performance than bulk equivalents. Increased thermoelectric efficiency of nanostructured materials have led to significant interests in developing thin film and nanowire structures. Here, we report on the first successful electrodeposition of lanthanum telluride thin films and nanowires. The electrodeposition of lanthanum telluride thin films is performed in ionic liquids at room temperature. The synthesis of nanowires involves electrodepositing lanthanum telluride arrays into anodic aluminum oxide (AAO) nanoporous membranes. These novel procedures can serve as an alternative means of simple, inexpensive and laboratory-environment friendly methods to synthesize nanostructured thermoelectric materials. The thermoelectric properties of thin films and nanowires will be presented to compare to current state-of-the-art thermoelectric materials. The morphologies and chemical compositions of the deposited films and nanowires are characterized using SEM and EDAX analysis.

  11. Low-temperature, solution-processed aluminum-doped zinc oxide as electron transport layer for stable efficient polymer solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Qianqian [College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101 (China); Bao, Xichang, E-mail: baoxc@qibebt.ac.cn [Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101 (China); Yu, Jianhua [College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Zhu, Dangqiang [Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101 (China); Zhang, Qian [College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Gu, Chuantao [Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101 (China); Dong, Hongzhou [College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Yang, Renqiang [Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101 (China); Dong, Lifeng, E-mail: DongLifeng@qust.edu.cn [College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Department of Physics, Hamline University, St. Paul, MN 55104 (United States)

    2016-04-30

    A simple low-temperature solution-processed zinc oxide (ZnO) and aluminum-doped ZnO (AZO) were synthesized and investigated as an electron transport layer (ETL) for inverted polymer solar cells. A solar cell with a blend of poly(4,8-bis-alkyloxy-benzo[1,2-b:4,5-b′] dithiophene-alt-alkylcarbonyl-thieno [3,4-b] thiophene) and (6,6)-phenyl-C71-butyric acid methyl ester as an active layer and AZO as ETL demonstrates a high power conversion efficiency (PCE) of 7.36% under the illumination of AM 1.5G, 100 mW/cm{sup 2}. Compared to the cells with ZnO ETL (PCE of 6.85%), the PCE is improved by 7.45% with the introduction of an AZO layer. The improved PCE is ascribed to the enhanced short circuit current density, which results from the electron transport property of the AZO layer. Moreover, AZO is a more stable interfacial layer than ZnO. The PCE of the solar cells with AZO as ETL retain 85% of their original value after storage for 120 days, superior to the 39% of cells with ZnO ETL. The results above indicate that a simple low-temperature solution-processed AZO film is an efficient and economical ETL for high-performance inverted polymer solar cells. Due to its environmental friendliness, good electrical properties, and simple preparation approach, AZO has the potential to be applied in high-performance, large-scale industrialization of solar cells and other electronic devices. - Highlights: • ZnO and AZO were synthesized by a simple low-temperature solution-processed method. • AZO films show high transmittance and conductivity. • The photovoltaic performance can be improved with AZO as ETL. • AZO-based devices demonstrate excellent stability, with 85% retained after 120 days.

  12. Properties of Nanostructure Bismuth Telluride Thin Films Using Thermal Evaporation

    Directory of Open Access Journals (Sweden)

    Swati Arora

    2017-01-01

    Full Text Available Bismuth telluride has high thermoelectric performance at room temperature; in present work, various nanostructure thin films of bismuth telluride were fabricated on silicon substrates at room temperature using thermal evaporation method. Tellurium (Te and bismuth (Bi were deposited on silicon substrate in different ratio of thickness. These films were annealed at 50°C and 100°C. After heat treatment, the thin films attained the semiconductor nature. Samples were studied by X-ray diffraction (XRD and scanning electron microscopy (SEM to show granular growth.

  13. Lead telluride with increased mechanical stability for cylindrical thermoelectric generators

    International Nuclear Information System (INIS)

    Schmitz, Andreas

    2013-01-01

    The aim of this work is to improve the mechanical stability of lead telluride (PbTe), trying to vary its mechanical properties independently from its thermoelectric properties. Thus the influence of material preparation as well as different dopants on the mechanical and thermoelectric properties of lead telluride is being analysed. When using appropriately set process parameters, milling and sintering of lead telluride increases the material's hardness. With sintering temperatures exceeding 300 C stable material of high relative density can be achieved. Milling lead telluride generates lattice defects leading to a reduction of the material's charge carrier density. These defects can be reduced by increased sintering temperatures. Contamination of the powder due to the milling process leads to bloating during thermal cycling and thus reduced density of the sintered material. In addition to that, evaporation of tellurium at elevated temperatures causes instability of the material's thermoelectric properties. Based on the experimental results obtained in this work, the best thermoelectric and mechanical properties can be obtained by sintering coarse powders at around 400 C. Within this work a concept was developed to vary the mechanical properties of lead telluride via synthesis of PbTe with electrically nondoping elements, which thus may keep the thermoelectric properties unchanged. Therefore, the mechanical and thermoelectric properties of Pb 1-x Ca x Te were investigated. Doping pure PbTe with calcium causes a significant increase of the material's hardness while only slightly decreasing the charge carrier density and thus keeping the thermoelectric properties apart from a slight reduction of the electrical conductivity nearly unchanged. The abovementioned concept is proven using sodium doped lead telluride, as it is used for thermoelectric generators: The additional doping with calcium again increases the material's hardness while its thermoelectric properties

  14. Synthesis and evaluation of lead telluride/bismuth antimony telluride nanocomposites for thermoelectric applications

    International Nuclear Information System (INIS)

    Ganguly, Shreyashi; Zhou Chen; Morelli, Donald; Sakamoto, Jeffrey; Uher, Ctirad; Brock, Stephanie L.

    2011-01-01

    Heterogeneous nanocomposites of p-type bismuth antimony telluride (Bi 2−x Sb x Te 3 ) with lead telluride (PbTe) nanoinclusions have been prepared by an incipient wetness impregnation approach. The Seebeck coefficient, electrical resistivity, thermal conductivity and Hall coefficient were measured from 80 to 380 K in order to investigate the influence of PbTe nanoparticles on the thermoelectric performance of nanocomposites. The Seebeck coefficients and electrical resistivities of nanocomposites decrease with increasing PbTe nanoparticle concentration due to an increased hole concentration. The lattice thermal conductivity decreases with the addition of PbTe nanoparticles but the total thermal conductivity increases due to the increased electronic thermal conductivity. We conclude that the presence of nanosized PbTe in the bulk Bi 2−x Sb x Te 3 matrix results in a collateral doping effect, which dominates transport properties. This study underscores the need for immiscible systems to achieve the decreased thermal transport properties possible from nanostructuring without compromising the electronic properties. - Graphical abstract: PbTe nanoparticles introduced into p-type Bi 2 Te 3 by incipient wetness results in decreased lattice thermal conductivity, but also acts as an electronic dopant, resulting in an overall decrease in thermoelectric performance. Highlights: ► Composites of PbTe nanoparticles in Bi 2−x Sb x Te 3 were formed by incipient wetness. ► PbTe nanoparticles leads to decreased κ l , consistent with phonon scattering. ► PbTe nanoparticles lead to decreased S and ρ, due to increased carriers. ► Collateral doping from PbTe leads to decreased ZT with increasing concentration. ► Immiscible systems are preferred for improved ZT.

  15. Preparation and photovoltaic properties of CdS quantum dot-sensitized solar cell based on zinc tin mixed metal oxides.

    Science.gov (United States)

    Cao, Jiupeng; Zhao, Yifan; Zhu, Yatong; Yang, Xiaoyu; Shi, Peng; Xiao, Hongdi; Du, Na; Hou, Wanguo; Qi, Genggeng; Liu, Jianqiang

    2017-07-15

    The present study reports a new type of quantum dot sensitized solar cells (QDSSCs) using the zinc tin mixed metal oxides (MMO) as the anode materials, which were obtained from the layered double hydroxide (LDH) precursor. The successive ionic layer adsorption and reaction (SILAR) method is applied to deposit CdS quantum dots. The effects of sensitizing cycles on the performance of CdS QDSSC are studied. Scanning electron microscopy (SEM), Transmission electron microscope (TEM) and X-ray diffraction (XRD) are used to identify the surface profile and crystal structure of the mixed metal oxides anode. The photovoltaic performance of the QDSSC is studied by the electrochemical method. The new CdS QDSSC exhibits power conversion efficiency (PCE) up to 0.48% when the anode was sensitized for eight cycles. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Using Spin-Coated Silver Nanoparticles/Zinc Oxide Thin Films to Improve the Efficiency of GaInP/(InGaAs/Ge Solar Cells

    Directory of Open Access Journals (Sweden)

    Po-Hsun Lei

    2018-06-01

    Full Text Available We synthesized a silver nanoparticle/zinc oxide (Ag NP/ZnO thin film by using spin-coating technology. The treatment solution for Ag NP/ZnO thin film deposition contained zinc acetate (Zn(CH3COO2, sodium hydroxide (NaOH, and silver nitrate (AgNO3 aqueous solutions. The crystalline characteristics, surface morphology, content of elements, and reflectivity of the Ag NPs/ZnO thin film at various concentrations of the AgNO3 aqueous solution were investigated using X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, atomic force microscopy, and ultraviolet–visible–near infrared spectrophotometry. The results indicated that the crystalline structure, Ag content, and reflectance of Ag NP/ZnO thin films depended on the AgNO3 concentration. Hybrid antireflection coatings (ARCs composed of SiNx and Ag NPs/ZnO thin films with various AgNO3 concentrations were deposited on GaInP/(InGaAs/Ge solar cells. We propose that the optimal ARC consists of SiNx and Ag NP/ZnO thin films prepared using a treatment solution of 0.0008 M AgNO3, 0.007 M Zn(CH3COO2, and 1 M NaOH, followed by post-annealing at 200 °C. GaInP/(AlGaAs/Ge solar cells with the optimal hybrid ARC and SiNx ARC exhibit a conversion efficiency of 34.1% and 30.2% with Voc = 2.39 and 2.4 V, Jsc = 16.63 and 15.37 mA/cm2, and fill factor = 86.1% and 78.8%.

  17. High-temperature thermoelectric behavior of lead telluride

    Indian Academy of Sciences (India)

    The central problem in thermoelectric material research is the selection of ... temperature range (400–1000 K), and bismuth telluride-based materials .... parent from the results that band non-parabolicity has a significant effect on the .... M P Singh thankfully acknowledges financial assistance from the Council of Scien-.

  18. Phase transition of bismuth telluride thin films grown by MBE

    DEFF Research Database (Denmark)

    Fülöp, Attila; Song, Yuxin; Charpentier, Sophie

    2014-01-01

    A previously unreported phase transition between Bi2Te3 and Bi4Te3 in bismuth telluride grown by molecular beam epitaxy is recorded via XRD, AFM, and SIMS observations. This transition is found to be related to the Te/Bi beam equivalent pressure (BEP) ratio. BEP ratios below 17 favor the formation...

  19. Fabrication of hybrid solar cells using poly(2,5-dimethoxyaniline) hexagonal structures and zinc oxide nanorods

    CSIR Research Space (South Africa)

    Mavundla, SE

    2012-04-01

    Full Text Available crystalline materials with one-dimensional morphology which improves the electron charge transport in the device. A distinctive photoluminescence quenching effect was observed indicating a photo-induced electron transfer. The solar cell devices fabricated from...

  20. Improved performance of low cost CuInS2 superstrate-type solar cells using Zinc assisted spray pyrolysis processing

    Science.gov (United States)

    Cheshme Khavar, Amir Hossein; Mahjoub, Ali Reza; Taghavinia, Nima

    2017-12-01

    Superstrate configuration CuInS2 (CIS) solar cells are fabricated using a spray pyrolysis method. We avoided selenization process, cyanide etching and CdS buffer layer, to keep the process ‘green’. CIS layers are formed by spray pyrolysis of an aqueous precursor ink containing metal chloride salts and thiourea at 350 °C. We investigated the effect of intentional Zn doping on structural, morphological and photovoltaic response of the fabricated CIS films by dissolving ZnCl2 in aqueous precursor solution. At a zinc doping level ranging between 0.25 and 1.00 mol%, Zn doping is found to improve the CIS crystal growth and surface morphology of CIS films. Compared with the performance of the non-doped CIS cell, the Zn-doped CIS solar cell displayed a remarkable efficiency enhancement of 58-97% and the maximum enhancement was obtained at a Zn content of 0.5 mol%. The device structure consists of    and show promising PCE of 4.29 % without any anti-reflection coating. Over the course of 300 d under ambient condition, the fabricated device showed only 1% loss in efficiency.

  1. Preparation of aluminum doped zinc oxide films with low resistivity and outstanding transparency by a sol–gel method for potential applications in perovskite solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Xingyue; Shen, Heping; Zhou, Chen [State Key Laboratory of New Ceramics & Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 10084 (China); Lin, Shiwei [Key Laboratory of Ministry of Education for Advanced Materials in Tropical Island Resources, Hainan University, Haikou 570228 (China); Li, Xin [State Key Laboratory of New Ceramics & Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 10084 (China); Zhao, Xiaochong [State Key Laboratory of New Ceramics & Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 10084 (China); Science and Technology on Surface Physics and Chemistry Laboratory, Mianyang 621907 (China); Deng, Xiangyun [Key Laboratory of Ministry of Education for Advanced Materials in Tropical Island Resources, Hainan University, Haikou 570228 (China); College of Physics and Electronic Information, Tianjin, Normal University, Tianjin 300387 (China); Li, Jianbao [State Key Laboratory of New Ceramics & Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 10084 (China); Key Laboratory of Ministry of Education for Advanced Materials in Tropical Island Resources, Hainan University, Haikou 570228 (China); Lin, Hong [State Key Laboratory of New Ceramics & Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 10084 (China)

    2016-04-30

    Highly transparent and conductive aluminum doped zinc oxide (AZO) films were prepared by sol–gel method on the glass substrates. The effects of doping concentration, annealing temperature and facing direction during annealing on the structural, electrical and optical properties of AZO films were studied by performing a series of characterizations including X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, UV–vis spectrophotometry, four-point probe method and Hall effect measurement system. The results showed that the AZO films were wurtzite crystallized with c-axis preferred orientation. A minimum resistivity of 1.8 × 10{sup −3} Ω cm and a transmittance above 90% were obtained for the film doped with 1.5 at.% aluminum, annealed at 510 °C and faced-down in the oven, which was among the best performance of the currently reported works based on sol–gel process. Moreover, energy level analysis revealed that the AZO film has a work function of 4.3 eV, exhibiting great potential in perovskite solar cell applications. - Highlights: • Highly transparent and conductive AZO films were prepared by sol–gel based process. • Different facing directions during annealing had effects on the carrier mobility. • Less aluminum ions at the grain boundary would favor the carrier transport. • The potential of AZO film in the perovskite solar cell application was discussed.

  2. Computational analysis of interfacial attachment kinetics and transport phenomena during liquid phase epitaxy of mercury cadmium telluride

    Energy Technology Data Exchange (ETDEWEB)

    Rasin, Igal; Brandon, Simon [Dept. of Chemical Engineering, Technion, Haifa 32000 (Israel); Ben Dov, Anne; Grimberg, Ilana; Klin, Olga; Weiss, Eliezer [SCD-Semi-Conductor Devices, P.O. Box 2250/99, Haifa 31021 (Israel)

    2010-07-01

    Deposition of mercury cadmium telluride (MCT) thin films, on lattice matched cadmium zinc telluride substrates, is often achieved via Liquid Phase Epitaxy (LPE). The yield and quality of these films, required for the production of infrared detector devices, is to a large extent limited by lack of knowledge regarding details of physical phenomena underlying the deposition process. Improving the understanding of these phenomena and their impact on the quality of the resultant films is therefore an important goal which can be achieved through relevant computational and/or experimental studies. We present a combined computational and experimental effort aimed at elucidating physical phenomena underlying the LPE of MCT via a slider growth process. The focus of the presentation will be results generated by a time-dependent three-dimensional model of mass transport, fluid flow, and interfacial attachment kinetics, which we have developed and applied in the analysis of this LPE process. These results, combined with experimental analyses, lead to an improved understanding of the role of different transport and kinetic phenomena underlying this growth process.

  3. Post-CMOS FinFET integration of bismuth telluride and antimony telluride thin-film-based thermoelectric devices on SoI substrate

    KAUST Repository

    Aktakka, Ethem Erkan; Ghafouri, Niloufar; Smith, Casey; Peterson, Rebecca Lorenz; Hussain, Muhammad Mustafa; Najafi, Khalil

    2013-01-01

    This letter reports, for the first time, heterogeneous integration of bismuth telluride (Bi2Te3) and antimony telluride (Sb 2Te3) thin-film-based thermoelectric ffect transistors) via a characterized TE-film coevaporationand shadow-mask patterning

  4. About thermo-electric properties of bismuth telluride doped by gadolinium

    International Nuclear Information System (INIS)

    Akperov, M.M.; Ismailov, Sh.S.; Shukyurova, A.A.

    2004-01-01

    Results of study of the Gd impurities effect on the bismuth telluride thermo-electric properties are presented. The experiment was carried out within the temperature range T=300-700 K. It is determined, that at temperature increase the energy level is appreciably closing up to bismuth telluride forbidden zone which makes up 0.16-0.24 eV. Such anomalous energy properties of gadolinium in telluride affect on material thermoelectric properties

  5. Efficiency increase in flexible bulk heterojunction solar cells with a nano-patterned indium zinc oxide anode

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dong Hwan; Seifter, Jason; Heeger, Alan J. [Center for Polymers and Organic Solids, University of California at Santa Barbara, Santa Barbara, California 93106-5090 (United States); Park, Jong Hyeok [School of Chemical Engineering and SAINT, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Choi, Dae-Geun [Nano-Mechanical Systems Research Division, Korea Institute of Machinery and Materials (KIMM), 171 Jang-dong, Yuseong-gu, Daejeon, 305-343 (Korea, Republic of)

    2012-11-15

    Efficient flexible bulk-heterojunction polymer solar cells based on PCDTBT/PC{sub 70}BM were successfully fabricated by a simple nano-imprint technique. The flexible nano-patterned IZO anode with ordered periodic dot structures led to improved light absorption and increased interfacial contact area between the anode and polymer as well as between the polymer and cathode. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Application of CBD-Zinc Sulfide Film as an Antireflection Coating on Very Large Area Multicrystalline Silicon Solar Cell

    Directory of Open Access Journals (Sweden)

    U. Gangopadhyay

    2007-01-01

    Full Text Available The low-cost chemical bath deposition (CBD technique is used to prepare CBD-ZnS films as antireflective (AR coating for multicrystalline silicon solar cells. The uniformity of CBD-ZnS film on large area of textured multicrystalline silicon surface is the major challenge of CBD technique. In the present work, attempts have been made for the first time to improve the rate of deposition and uniformity of deposited film by controlling film stoichiometry and refractive index and also to minimize reflection loss by proper optimization of molar percentage of different chemical constituents and deposition conditions. Reasonable values of film deposition rate (12.13 Å′/min., good film uniformity (standard deviation <1, and refractive index (2.35 along with a low percentage of average reflection (6-7% on a textured mc-Si surface are achieved with proper optimization of ZnS bath. 12.24% efficiency on large area (125 mm × 125 mm multicrystalline silicon solar cells with CBD-ZnS antireflection coating has been successfully fabricated. The viability of low-cost CBD-ZnS antireflection coating on large area multicrystalline silicon solar cell in the industrial production level is emphasized.

  7. Enhancement of zinc oxide-mediated solar light decoloration of Acid Yellow 99 dye by addition of β-CD

    Science.gov (United States)

    Pitchaimuthu, Sakthivel; Rajalakshmi, Subramanian; Kannan, Nagarathinam; Velusamy, Ponnusamy

    2015-06-01

    In the current work, the commercially available ZnO photocatalyst was used to investigate the photodecoloration of Acid yellow 99 (AY99) dye under solar light radiation. Promising enhancement of photodecoloration of AY99 dye was also achieved by the addition of β-cyclodextrin (β-CD) with the ZnO (ZnO-β-CD). The effects of process parameters such as initial concentration, pH, catalyst loading, and illumination time on the extent of decoloration were investigated. The optimum catalyst loading was observed at 2.0 g/L. The higher photoactivity of ZnO-β-CD/solar light system than ZnO/solar light system can be ascribed due to the ligand to metal charge transfer (LMCT) from β-CD to ZnII. The complexation patterns have been confirmed with UV-visible and FT-IR spectroscopy and the interaction between ZnO and β-CD has been characterized by FE-SEM, powder XRD analysis, and UV-visible diffuse reflectance spectroscopy.

  8. Development of Annealing-Free, Solution-Processable Inverted Organic Solar Cells with N-Doped Graphene Electrodes using Zinc Oxide Nanoparticles.

    Science.gov (United States)

    Jung, Seungon; Lee, Junghyun; Seo, Jihyung; Kim, Ungsoo; Choi, Yunseong; Park, Hyesung

    2018-02-14

    An annealing-free process is considered as a technological advancement for the development of flexible (or wearable) organic electronic devices, which can prevent the distortion of substrates and damage to the active components of the device and simplify the overall fabrication process to increase the industrial applications. Owing to its outstanding electrical, optical, and mechanical properties, graphene is seen as a promising material that could act as a transparent conductive electrode for flexible optoelectronic devices. Owing to their high transparency and electron mobility, zinc oxide nanoparticles (ZnO-NP) are attractive and promising for their application as charge transporting materials for low-temperature processes in organic solar cells (OSCs), particularly because most charge transporting materials require annealing treatments at elevated temperatures. In this study, graphene/annealing-free ZnO-NP hybrid materials were developed for inverted OSC by successfully integrating ZnO-NP on the hydrophobic surface of graphene, thus aiming to enhance the applicability of graphene as a transparent electrode in flexible OSC systems. Chemical, optical, electrical, and morphological analyses of ZnO-NPs showed that the annealing-free process generates similar results to those provided by the conventional annealing process. The approach was effectively applied to graphene-based inverted OSCs with notable power conversion efficiencies of 8.16% and 7.41% on the solid and flexible substrates, respectively, which promises the great feasibility of graphene for emerging optoelectronic device applications.

  9. Fabrication of layered hydroxide zinc nitrate films and their conversion to ZnO nanosheet assemblies for use in dye-sensitized solar cells

    Directory of Open Access Journals (Sweden)

    Takuya Yuki

    2015-03-01

    Full Text Available Layered hydroxide zinc nitrate (LHZN; Zn5(NO32(OH8·xH2O films were fabricated on glass or plastic substrates by a chemical bath deposition method combined with a homogeneous precipitation in methanolic solutions. High- or low-temperature pyrolytic decomposition of the LHZN films having two-dimensional morphology was attempted to obtain porous ZnO nanosheet-assembly films. The LHZN films were converted into porous ZnO films by pyrolyzing at temperatures above 400 °C, while porous LHZN/ZnO hybrid films were obtained by pyrolyzing at a lower temperature of 120 °C without morphological changes. The pyrolyzed ZnO films were applied to dye-sensitized solar cells (DSSCs, resulting in the generation of relatively high open-circuit voltages. The low-temperature pyrolysis enabled us to fabricate the LHZN/ZnO film even on the plastic substrate. Actually a cell using the LHZN/ZnO film on an indium tin oxide-coated polyethylene naphthalate substrate showed an energy conversion efficiency of 2.08% with a high open-circuit voltage around 0.70 V.

  10. Electrodeposition of zinc oxide/tetrasulfonated copper phthalocyanine hybrid thin film for dye-sensitized solar cell application

    Energy Technology Data Exchange (ETDEWEB)

    Luo Xinze [Key Laboratory of Polyoxometalates Science of Ministry of Education, College of Chemistry, Northeast Normal University, Changchun 130024 (China); College of Chemistry and Biological Science, Yili Normal University, Yining 835000, (China); Xu Lin, E-mail: linxu@nenu.edu.cn [Key Laboratory of Polyoxometalates Science of Ministry of Education, College of Chemistry, Northeast Normal University, Changchun 130024 (China); Xu Bingbing; Li Fengyan [Key Laboratory of Polyoxometalates Science of Ministry of Education, College of Chemistry, Northeast Normal University, Changchun 130024 (China)

    2011-05-15

    Hybrid film of zinc oxide (ZnO) and tetrasulfonated copper phthalocyanine (TSPcCu) was grown on an indium tin oxide (ITO) glass by one-step cathodic electrodeposition from aqueous mixtures of Zn(NO{sub 3}){sub 2}, TSPcCu and KCl. The addition of TSPcCu strongly influences the morphology and crystallographic orientation of the ZnO. The nanosheets stack of ZnO leads to a porous surface structure which is advantageous to further adsorb organic dyes. The photovoltaic properties were investigated by assembling the DSSC device based on both the only ZnO film and the ZnO/TSPcCu hybrid films. Photoelectrochemical analysis revealed that the optimized DSSC device with TSPcCu represented a more than three-fold improvement in power conversion efficiency than the device without TSPcCu. The DSSC based on ZnO/TSPcCu hybrid films demonstrates an open circuit voltage of 0.308 V, a short circuit current of 90 {mu}A cm{sup -2}, a fill factor of 0.26, and a power conversion efficiency of 0.14%.

  11. Electrodeposition of zinc oxide/tetrasulfonated copper phthalocyanine hybrid thin film for dye-sensitized solar cell application

    International Nuclear Information System (INIS)

    Luo Xinze; Xu Lin; Xu Bingbing; Li Fengyan

    2011-01-01

    Hybrid film of zinc oxide (ZnO) and tetrasulfonated copper phthalocyanine (TSPcCu) was grown on an indium tin oxide (ITO) glass by one-step cathodic electrodeposition from aqueous mixtures of Zn(NO 3 ) 2 , TSPcCu and KCl. The addition of TSPcCu strongly influences the morphology and crystallographic orientation of the ZnO. The nanosheets stack of ZnO leads to a porous surface structure which is advantageous to further adsorb organic dyes. The photovoltaic properties were investigated by assembling the DSSC device based on both the only ZnO film and the ZnO/TSPcCu hybrid films. Photoelectrochemical analysis revealed that the optimized DSSC device with TSPcCu represented a more than three-fold improvement in power conversion efficiency than the device without TSPcCu. The DSSC based on ZnO/TSPcCu hybrid films demonstrates an open circuit voltage of 0.308 V, a short circuit current of 90 μA cm -2 , a fill factor of 0.26, and a power conversion efficiency of 0.14%.

  12. Application of CBD-Zinc Sulfide Film as an Antireflection Coating on Very Large Area Multicrystalline Silicon Solar Cell

    OpenAIRE

    U. Gangopadhyay; K. Kim; S. K. Dhungel; H. Saha; J. Yi

    2007-01-01

    The low-cost chemical bath deposition (CBD) technique is used to prepare CBD-ZnS films as antireflective (AR) coating for multicrystalline silicon solar cells. The uniformity of CBD-ZnS film on large area of textured multicrystalline silicon surface is the major challenge of CBD technique. In the present work, attempts have been made for the first time to improve the rate of deposition and uniformity of deposited film by controlling film stoichiometry and refractive index and also to minimize...

  13. Nanobeads of zinc oxide with rhodamine B dye as a sensitizer for dye sensitized solar cell application

    Energy Technology Data Exchange (ETDEWEB)

    Baviskar, P.K. [Thin Film and Nano Science Laboratory, Department of Physics, School of Physical Sciences, North Maharashtra University, Jalgaon 425 001, MS (India); Zhang, J.B. [Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Gupta, V.; Chand, S. [Organic and Hybrid Solar Cell, Physics of Energy Harvesting Division, Dr. K. S. Krishnan Marg, National Physical Laboratory, New Delhi 110012 (India); Sankapal, B.R., E-mail: brsankapal@rediffmail.com [Thin Film and Nano Science Laboratory, Department of Physics, School of Physical Sciences, North Maharashtra University, Jalgaon 425 001, MS (India)

    2012-01-05

    Highlights: > Synthesis of ZnO film was done at room temperature (27 deg. C). > Simple and inexpensive chemical bath deposition method was employed. > The as deposited film consists of mixed phases of hydroxide and oxide. > The post annealing was done at 200 deg. C in order to remove hydroxide phase. > Low-cost, metal free Rhodamine B dye was used for DSSC application. - Abstract: Cost effective, ruthenium metal free rhodamine B dye has been chemically adsorbed on ZnO films consisting of nanobeads to serve as a photo anode in dye sensitized solar cells. These ZnO films were chemically synthesized at room temperature (27 deg. C) on to fluorine doped tin oxide (FTO) coated glass substrates followed by annealing at 200 deg. C. These films consisting of inter connected nanobeads (20-40 nm) which are due to the agglomeration of very small size particles (3-5 nm) leading to high surface area. The film shows wurtzite structure having high crystallinity with optical direct band gap of 3.3 eV. Optical absorbance measurements for rhodamine B dye covered ZnO film revealed the good coverage in the visible region (460-590 nm) of the solar spectrum. With poly-iodide liquid as an electrolyte, device exhibits photon to electric energy conversion efficiency ({eta}) of 1.26% under AM 1.5G illumination at 100 mW/cm{sup 2}.

  14. The charge-transfer property and the performance of dye-sensitized solar cells of nitrogen doped zinc oxide

    International Nuclear Information System (INIS)

    Zhang Lingyun; Yang Yulin; Fan Ruiqing; Chen Haiyan; Jia Ruokun; Wang Yonghui; Ma Liqun; Wang Yazhen

    2012-01-01

    Highlights: ► Two methods (the solution and annealing methods) are used to prepare nitrogen-doped ZnO. ► The charge-transfer properties of N-doping ZnO are investigated. ► The overall conversion efficiency of N-doped ZnO-based dye-sensitized solar cells is successfully improved by N doping. - Abstract: In this study two methods, namely the solution and annealing methods, were used to prepare nitrogen-doped ZnO. The X-ray photoelectron spectroscopy (XPS) was performed to identify the composition and chemical states of N-doped ZnO. The N doping by the solution method was found to effectively decrease the acceptor effects. Surface photovoltage measurements (SPS) revealed a redshift of the threshold wavelength for the N-doped ZnO. And the recombination of photoinduced electron–hole pairs in this semiconductor material was obviously suppressed. The N-doped ZnO (solution method) exhibits the best performances among all the materials, even superior to N-doped ZnO (annealing method). Its J sc and η values (9.35 mA/cm 2 and 2.64%) have enhanced by several times compared with un-doped ZnO (J sc , 2.85 mA/cm 2 ; η, 0.67%). The overall conversion efficiency of ZnO-based dye-sensitized solar cells was successfully improved by the N doping.

  15. Method of Creating Micro-scale Silver Telluride Grains Covered with Bismuth Nanoparticles

    Science.gov (United States)

    Kim, Hyun-Jung (Inventor); Choi, Sang Hyouk (Inventor); King, Glen C. (Inventor); Park, Yeonjoon (Inventor); Lee, Kunik (Inventor)

    2014-01-01

    Provided is a method of enhancing thermoelectric performance by surrounding crystalline semiconductors with nanoparticles by contacting a bismuth telluride material with a silver salt under a substantially inert atmosphere and a temperature approximately near the silver salt decomposition temperature; and recovering a metallic bismuth decorated material comprising silver telluride crystal grains.

  16. The charge-transfer property and the performance of dye-sensitized solar cells of nitrogen doped zinc oxide

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Lingyun [Department of Chemistry, Harbin Institute of Technology, Harbin 150001 (China); School of Chemical Engineering, Northeast Dianli University, Jilin 132012 (China); Yang Yulin, E-mail: ylyang@hit.edu.cn [Department of Chemistry, Harbin Institute of Technology, Harbin 150001 (China); Fan Ruiqing, E-mail: fanruiqing@hit.edu.cn [Department of Chemistry, Harbin Institute of Technology, Harbin 150001 (China); Chen Haiyan [Department of Chemistry, Harbin Institute of Technology, Harbin 150001 (China); Jia Ruokun [School of Chemical Engineering, Northeast Dianli University, Jilin 132012 (China); Wang Yonghui [Faculty of Chemistry, Northeast Normal University, Changchun, Jilin 130024 (China); Ma Liqun; Wang Yazhen [School of Material Science of Engineering, Qiqihar University, Qiqihar 161006 (China)

    2012-07-25

    Highlights: Black-Right-Pointing-Pointer Two methods (the solution and annealing methods) are used to prepare nitrogen-doped ZnO. Black-Right-Pointing-Pointer The charge-transfer properties of N-doping ZnO are investigated. Black-Right-Pointing-Pointer The overall conversion efficiency of N-doped ZnO-based dye-sensitized solar cells is successfully improved by N doping. - Abstract: In this study two methods, namely the solution and annealing methods, were used to prepare nitrogen-doped ZnO. The X-ray photoelectron spectroscopy (XPS) was performed to identify the composition and chemical states of N-doped ZnO. The N doping by the solution method was found to effectively decrease the acceptor effects. Surface photovoltage measurements (SPS) revealed a redshift of the threshold wavelength for the N-doped ZnO. And the recombination of photoinduced electron-hole pairs in this semiconductor material was obviously suppressed. The N-doped ZnO (solution method) exhibits the best performances among all the materials, even superior to N-doped ZnO (annealing method). Its J{sub sc} and {eta} values (9.35 mA/cm{sup 2} and 2.64%) have enhanced by several times compared with un-doped ZnO (J{sub sc}, 2.85 mA/cm{sup 2}; {eta}, 0.67%). The overall conversion efficiency of ZnO-based dye-sensitized solar cells was successfully improved by the N doping.

  17. Electrical properties of cadmium telluride films doped with antimony

    International Nuclear Information System (INIS)

    Atdaev, B.S.; Garyagdyev, G.; Grin', V.F.; Noskov, A.I.

    1989-01-01

    Effect of cadmium telluride doping with antimony on electric and photoelectric properties is investigated. Temperature dependence of dark (σ d ) and photoconductivity (σ p ) during excitation from the range of proper absorption in the temperature range 77-300 K and spectral distribution of photoconductivity at 300 K are investigated. It is shown that in the process of doping antimony diffusses intensively over CdTe grain boundaries, decreasing potential barriers between them and due to diffusion into CdTe grains it changes their electrical properties. The acceptor character of antimony impurity can be caused by antimony diffusion into tellurium sublattice owing to proximity of their ionic and covalent radii

  18. XAFS studies of nickel-doped lead telluride

    International Nuclear Information System (INIS)

    Radisavljevic, Ivana; Novakovic, Nikola; Ivanovic, Nenad; Romcevic, Nebojsa; Manasijevic, Miodrag; Mahnke, Heinz-Eberhard

    2009-01-01

    The problem of impurities and defect states in lead telluride-based semiconductors is of crucial importance for their practical applications. X-ray absorption fine structure (XAFS) techniques are capable to address some of the key issues regarding impurities position, their valent state, as well as the local structural changes of the host lattice in the immediate surrounding of the impurity atoms. In this paper we present the results of the Ni K-absorption edge XAFS studies of Ni-doped PbTe at different temperatures. Analysis of near edge and extended XAFS regions of the measured spectra provided information about exact local environment and lattice ordering around Ni atoms.

  19. Performance of Dye-Sensitized Solar Cells (DSSCs) Fabricated with Zinc Oxide (ZnO) Nanpowders and Nanorods

    Science.gov (United States)

    Chatterjee, Suman

    2018-03-01

    Due to their high efficiencies, along with lower production costs, many researchers are working on dye-sensitized solar cells (DSSCs) over last few decades as a substitute technology for nonconventional energy. Nanostructured ZnO has got many interesting properties such as wide band gap, large exciton binding energy, good exciton stability, and high breakdown strength, which are applicable as DSSC electrodes. This present work compares the device properties of DSSC fabricated using ZnO nanorods on a ZnO film and ZnO nanopowders. Different types of ZnO photoanode and dye combinations are used to study the stability and photovoltaic properties of the DSSC cell. The photovoltaic properties of the ZnO-based DSSC samples were systematically investigated. The photovoltaic properties of fabricated cell obtained are discussed in the light of band structure and density of states of different types of ZnO nanolayers. The ZnO nanorods fabricated through the sol-gel route have more uniform thickness resulting in enhanced photovoltaic properties of the fabricated device.

  20. Application of cadmium telluride detectors to high energy computed tomography

    International Nuclear Information System (INIS)

    Glasser, F.; Thomas, G.; Cuzin, M.; Verger, L.

    1991-01-01

    15 years ago, Cadmium Telluride detectors have been investigated in our laboratory as possible detectors for medical scanners [1]. Today most of these machines are using high pressure Xenon gas as multicells detectors, BGO or CdWO 4 scintillators for industrial computerized tomography. Xenon gas detectors are well suited for detection of 100 KeV X-rays and enables to build 1000 cells homogeneous detector with a dynamic range of 3 decades. BGO and CdWO 4 scintillators, associated with photomultipliers or photodiodes are used for higher energy (400 KeV). They present a low afterglow and a dynamic range of 4 to 5 decades. Non destructive testing of very absorbing objects (eg 2 m diameter solid rocket motor) by X-ray tomography requires much higher energy X-rays (16 MeV) and doses up to 12000 rads/min at 1 meter. For this application Cadmium Telluride detectors operating as photoconductors are well suited. A prototype of tomograph machine, able to scan 0.5 m diameter high density objects has been realized with 25 CdTe detectors (25x15x0.8 mm 3 ). It produces good quality 1024x1024 tomographic images

  1. Kelvin probe studies of cesium telluride photocathode for AWA photoinjector

    Energy Technology Data Exchange (ETDEWEB)

    Wisniewski, Eric E., E-mail: ewisniew@anl.gov [High Energy Physics Division, Argonne National Laboratory, 9700 S. Cass, Lemont, IL 60439 (United States); Physics Department, Illinois Institute of Technology, 3300 South Federal Street, Chicago, IL 60616 (United States); Velazquez, Daniel [High Energy Physics Division, Argonne National Laboratory, 9700 S. Cass, Lemont, IL 60439 (United States); Physics Department, Illinois Institute of Technology, 3300 South Federal Street, Chicago, IL 60616 (United States); Yusof, Zikri, E-mail: zyusof@hawk.iit.edu [High Energy Physics Division, Argonne National Laboratory, 9700 S. Cass, Lemont, IL 60439 (United States); Physics Department, Illinois Institute of Technology, 3300 South Federal Street, Chicago, IL 60616 (United States); Spentzouris, Linda; Terry, Jeff [Physics Department, Illinois Institute of Technology, 3300 South Federal Street, Chicago, IL 60616 (United States); Sarkar, Tapash J. [Rice University, 6100 Main, Houston, TX 77005 (United States); Harkay, Katherine [Accelerator Science Division, Argonne National Laboratory, 9700 S. Cass, Lemont, IL 60439 (United States)

    2013-05-21

    Cesium telluride is an important photocathode as an electron source for particle accelerators. It has a relatively high quantum efficiency (>1%), is sufficiently robust in a photoinjector, and has a long lifetime. This photocathode is grown in-house for a new Argonne Wakefield Accelerator (AWA) beamline to produce high charge per bunch (≈50nC) in a long bunch train. Here, we present a study of the work function of cesium telluride photocathode using the Kelvin probe technique. The study includes an investigation of the correlation between the quantum efficiency and the work function, the effect of photocathode aging, the effect of UV exposure on the work function, and the evolution of the work function during and after photocathode rejuvenation via heating. -- Highlights: ► The correlation between Quantum Efficiency (QE) and work function. ► How QE and work function evolve together. ► Rejuvenation of the photocathode via heating and the effect on work function. ► The effects on the work function due to exposure to UV light.

  2. Magneto-photoconductivity of three dimensional topological insulator bismuth telluride

    Science.gov (United States)

    Cao, Bingchen; Eginligil, Mustafa; Yu, Ting

    2018-03-01

    Magnetic field dependence of the photocurrent in a 3D topological insulator is studied. Among the 3D topological insulators bismuth telluride has unique hexagonal warping and spin texture which has been studied by photoemission, scanning tunnelling microscopy and transport. Here, we report on low temperature magneto-photoconductivity, up to 7 T, of two metallic bismuth telluride topological insulator samples with 68 and 110 nm thicknesses excited by 2.33 eV photon energy along the magnetic field perpendicular to the sample plane. At 4 K, both samples exhibit negative magneto-photoconductance below 4 T, which is as a result of weak-antilocalization of Dirac fermions similar to the previous observations in electrical transport. However the thinner sample shows positive magneto-photoconductance above 4 T. This can be attributed to the coupling of surface states. On the other hand, the thicker sample shows no positive magneto-photoconductance up to 7 T since there is only one surface state at play. By fitting the magneto-photoconductivity data of the thicker sample to the localization formula, we obtain weak antilocalization behaviour at 4, 10, and 20 K, as expected; however, weak localization behaviour at 30 K, which is a sign of surface states masked by bulk states. Also, from the temperature dependence of phase coherence length bulk carrier-carrier interaction is identified separately from the surface states. Therefore, it is possible to distinguish surface states by magneto-photoconductivity at low temperature, even in metallic samples.

  3. Cadmium Telluride-Titanium Dioxide Nanocomposite for Photodegradation of Organic Substance.

    Science.gov (United States)

    Ontam, Areeporn; Khaorapapong, Nithima; Ogawa, Makoto

    2015-12-01

    Cadmium telluride-titanium dioxide nanocomposite was prepared by hydrothermal reaction of sol-gel derived titanium dioxide and organically modified cadmium telluride. The crystallinity of titanium dioxide in the nanocomposite was higher than that of pure titanium dioxide obtained by the reaction under the same temperature and pressure conditions, showing that cadmium telluride induced the crystallization of titanium dioxide. Diffuse reflectance spectrum of the nanocomposite showed the higher absorption efficiency in the UV-visible region due to band-gap excitation of titanium dioxide. The nanocomposite significantly showed the improvement of photocatalytic activity for 4-chlorophenol with UV light.

  4. Spectroscopic, microscopic, and internal stress analysis in cadmium telluride grown by close-space sublimation

    International Nuclear Information System (INIS)

    Manciu, Felicia S.; Salazar, Jessica G.; Diaz, Aryzbe; Quinones, Stella A.

    2015-01-01

    High quality materials with excellent ordered structure are needed for developing photovoltaic and infrared devices. With this end in mind, the results of our research prove the importance of a detailed, comprehensive spectroscopic and microscopic analysis in assessing cadmium telluride (CdTe) characteristics. The goal of this work is to examine not only material crystallinity and morphology, but also induced stress in the deposit material. A uniform, selective growth of polycrystalline CdTe by close-space sublimation on patterned Si(111) and Si(211) substrates is demonstrated by scanning electron microscopy images. Besides good crystallinity of the samples, as revealed by both Raman scattering and Fourier transform infrared absorption investigations, the far-infrared transmission data also show the presence of surface optical phonon modes, which is direct evidence of confinement in such a material. The qualitative identification of the induced stress was achieved by performing confocal Raman mapping microscopy on sample surfaces and by monitoring the existence of the rock-salt and zinc-blende structural phases of CdTe, which were associated with strained and unstrained morphologies, respectively. Although the induced stress in the material is still largely due to the high lattice mismatch between CdTe and the Si substrate, the current results provide a direct visualization of its partial release through the relaxation effect at crystallite boundaries and of preferential growth directions of less strain. Our study, thus offers significant value for improvement of material properties, by targeting the needed adjustments in the growth processes. - Highlights: • Assessing the characteristics of CdTe deposited on patterned Si substrates • Proving the utility of confocal Raman microscopy in monitoring the induced stress • Confirming the partial stress release through the grain boundary relaxation effect • Demonstrating the phonon confinement effect in low

  5. Investigation to optimize the energy resolution and efficiency of cadmium(zinc)telluride for photon measurements

    Science.gov (United States)

    Kim, Hadong

    While the investigations of the Cd(Zn)Te characteristics were completed, a new method to make arbitrary anode shapes, without the troublesome shadow mask technique, was found. With this technique, the two-anode geometry Cd(Zn)Te detector was introduced and tested. The semiconductor performance of the two-anode geometry detectors for the incoming gamma rays of 241Am, 57Co, and 137Cs were compared to the responses of the planar device. The very promising photon energy resolutions of 9.3 and 5.4% FWHM were obtained with the two-anode geometry detector for the gamma rays energies of 122 keV and 662 keV, respectively, while no discernible full energy peaks were apparent with the planar detector. Several simulation programs that are very easy to handle were developed as useful tools for investigating the complicated gamma ray pulse height distributions, which were due to the energy deposition events inside the semiconductors. Comparisons to the known values and with the results from other application programs, validated the information obtained from the simulation programs, which were developed during this research effort. A graphical user interface (GUI) was designed for the user's convenience in order to enter the required input parameters for the specific requirements of each simulation programs. The idealized noise free spectra for the planar detector and for the small pixel geometry detector were successfully obtained by applying Monte Carlo techniques.

  6. Effect of carboxyl anchoring groups in asymmetric zinc phthalocyanine with large steric hindrance on the dye-sensitized solar cell performance

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Wenye; Peng, Bosi; Lin, Li; Li, Renjie; Zhang, Jing, E-mail: jzhang03@whu.edu.cn; Peng, Tianyou, E-mail: typeng@whu.edu.cn

    2015-08-01

    Asymmetric zinc phthalocyanines containing tribenzonaphtho-condensed porphyrazine with six bulky diphenylphenoxy and one or two carboxyl groups are used as sensitizers for dye-sensitized solar cells (DSSCs). It is found that Zn-tri-PcNc-4 having two carboxyl groups shows a slight redshift in the Q-band absorption but a significantly decreased absorbance as compared with Zn-tri-PcNc-8 having one carboxyl group, and Zn-tri-PcNc-4 can be more stably and perpendicularly grafted onto the TiO{sub 2} surface than Zn-tri-PcNc-8, which further leads to the differences in the interfacial charge transfer dynamics and dye-loaded amount. Zn-tri-PcNc-4 with two carboxyl groups grafted onto the TiO{sub 2} electrode surface of DSSC results in a photovoltaic conversion efficiency of 3.22%, higher than that (3.01%) of the analog with one carboxyl group (Zn-tri-PcNc-8), which exhibits a lower short-circuit current but much higher open-circuit voltage. The additional carboxyl group in Zn-tri-PcNc-4 leads to the enhanced dye-loaded amount and the molecular orbital energy level shift toward positive direction, causing more efficient electron injection and higher short-circuit current than Zn-tri-PcNc-8; while the two carboxyl groups of Zn-tri-PcNc-4 would cause more protonation of TiO{sub 2} surface, which possibly leads to the downward shift of TiO{sub 2} conduction band edge, and then to the decreased open-circuit voltage. The present results demonstrate the molecular engineering aspect of ZnPc dyes in which the fine tuning of the energy levels and molecular structures is crucial for high conversion efficiency of DSSCs. - Highlights: • ZnPcs with six diphenylphenoxy and one/two carboxyl groups are used as dyes for DSSCs. • Effect of carboxyl group number on the ZnPc-sensitized cell property are scrutinized. • Grafting two carboxyl groups on ZnPc leads to the enhanced photocurrent and efficiency. • ZnPc with one COOH has a higher open-circuit voltage than its analog with two

  7. Solution-processed zinc oxide/polyethylenimine nanocomposites as tunable electron transport layers for highly efficient bulk heterojunction polymer solar cells.

    Science.gov (United States)

    Chen, Hsiu-Cheng; Lin, Shu-Wei; Jiang, Jian-Ming; Su, Yu-Wei; Wei, Kung-Hwa

    2015-03-25

    In this study, we employed polyethylenimine-doped sol-gel-processed zinc oxide composites (ZnO:PEI) as efficient electron transport layers (ETL) for facilitating electron extraction in inverted polymer solar cells. Using ultraviolet photoelectron spectroscopy, synchrotron grazing-incidence small-angle X-ray scattering and transmission electron microscopy, we observed that ZnO:PEI composite films' energy bands could be tuned considerably by varying the content of PEI up to 7 wt %-the conduction band ranged from 4.32 to 4.0 eV-and the structural order of ZnO in the ZnO:PEI thin films would be enhanced to align perpendicular to the ITO electrode, particularly at 7 wt % PEI, facilitating electron transport vertically. We then prepared two types of bulk heterojunction systems-based on poly(3-hexylthiophene) (P3HT):phenyl-C61-butryric acid methyl ester (PC61BM) and benzo[1,2-b:4,5-b́]dithiophene-thiophene-2,1,3-benzooxadiazole (PBDTTBO):phenyl-C71-butryric acid methyl ester (PC71BM)-that incorporated the ZnO:PEI composite layers. When using a composite of ZnO:PEI (93:7, w/w) as the ETL, the power conversion efficiency (PCE) of the P3HT:PC61BM (1:1, w/w) device improved to 4.6% from a value of 3.7% for the corresponding device that incorporated pristine ZnO as the ETL-a relative increase of 24%. For the PBDTTBO:PC71BM (1:2, w/w) device featuring the same amount of PEI blended in the ETL, the PCE improved to 8.7% from a value of 7.3% for the corresponding device that featured pure ZnO as its ETL-a relative increase of 20%. Accordingly, ZnO:PEI composites can be effective ETLs within organic photovoltaics.

  8. Sputtered indium-tin oxide/cadmium telluride junctions and cadmium telluride surfaces

    International Nuclear Information System (INIS)

    Courreges, F.G.; Fahrenbruch, A.L.; Bube, R.H.

    1980-01-01

    The properties of indium-tin oxide (ITO)/CdTe junction solar cells prepared by rf sputtering of ITO on P-doped CdTe single-crystal substrates have been investigated through measurements of the electrical and photovoltaic properties of ITO/CdTe and In/CdTe junctions, and of electron beam induced currents (EBIC) in ITO/CdTe junctions. In addition, surface properties of CdTe related to the sputtering process were investigated as a function of sputter etching and thermal oxidation using the techniques of surface photovoltage and photoluminescence. ITO/CdTe cells prepared by this sputtering method consist of an n + -ITO/n-CdTe/p-CdTe buried homojunction with about a 1-μm-thick n-type CdTe layer formed by heating of the surface of the CdTe during sputtering. Solar efficiencies up to 8% have been observed with V/sub 0c/=0.82 V and J/sub s/c=14.5 mA/cm 2 . The chief degradation mechanism involves a decrease in V/sub 0c/ with a transformation of the buried homojunction structure to an actual ITO/CdTe heterojunction

  9. Electrochemical Studies of Lead Telluride Behavior in Acidic Nitrate Solutions

    Directory of Open Access Journals (Sweden)

    Rudnik E.

    2015-04-01

    Full Text Available Electrochemistry of lead telluride stationary electrode was studied in nitric acid solutions of pH 1.5-3.0. E-pH diagram for Pb-Te-H2O system was calculated. Results of cyclic voltammetry of Pb, Te and PbTe were discussed in correlation with thermodynamic predictions. Anodic dissolution of PbTe electrode at potential approx. -100÷50 mV (SCE resulted in tellurium formation, while above 300 mV TeO2 was mainly produced. The latter could dissolve to HTeO+2 under acidic electrolyte, but it was inhibited by increased pH of the bath.

  10. Effect of thallium impurity on hole scattering in lead telluride

    International Nuclear Information System (INIS)

    Kajdanov, V.I.; Nemov, S.A.

    1981-01-01

    Hole mobility in PbTe monocrystalline specimens in the temperature range from 4.2 to 300 K has been investigated. Detected is a sharp increase in scattering cross section of light and heavy holes in the specimens having the Hall hole concentration p approximately (5+-9)x10 19 cm -3 explained by resonant scattering into a band of quasilocal states of thallium located lower than the ceiling of heavy carrier zone by 0.01+-0.01 eV. Very large differences in resonant scattering of current carriers into the quasilocal states of In and Tl in PbTe result from the inertial polarizability of a crystal. The same mechanism is used to explain long-lived relaxation of zone electron concentration in lead telluride and Pbsub(1-x)Snsub(x)Te doped with indium [ru

  11. Megapixel mercury cadmium telluride focal plane arrays for infrared imaging out to 12 microns, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose the fabrication of large format, long wave infrared (LWIR) mercury cadmium telluride (HgCdTe or MCT) detector arrays where the cutoff wavelength is...

  12. Niobium and zirconium telluride thin films prepared by sputtering

    International Nuclear Information System (INIS)

    Kassem, M.; Pailharey, D.; Mathey, Y.

    2000-01-01

    A versatile procedure of sputter deposition, well adapted for getting a large of Te/M ratios (with M = Zr or Nb), has led to the synthesis of several highly anisotropic zirconium and niobium poly tellurides in thin film form. Upon tuning the two key parameters of the process, i.e., the Te percentage in the target and the substrate temperature during the deposition, preparation of systems ranging from ZrTe 0 .72 to ZrTe 6 .7, on the one hand, and from NbTe 1 .28 to NbTe 7 .84, on the other, has been achieved. Besides their amorphous or crystalline (with or without preferential orientations) behavior and their relationship to known structural types, the most striking feature of these films is their large departure from the stoichiometry of the bulk Mte x reference compounds. This peculiarity, together with the possible changes of composition under annealing, are described and interpreted in terms of variable of Te and M atoms trapped or intercalated within the parent structures. (author)

  13. Precision timing detectors with cadmium-telluride sensor

    Science.gov (United States)

    Bornheim, A.; Pena, C.; Spiropulu, M.; Xie, S.; Zhang, Z.

    2017-09-01

    Precision timing detectors for high energy physics experiments with temporal resolutions of a few 10 ps are of pivotal importance to master the challenges posed by the highest energy particle accelerators such as the LHC. Calorimetric timing measurements have been a focus of recent research, enabled by exploiting the temporal coherence of electromagnetic showers. Scintillating crystals with high light yield as well as silicon sensors are viable sensitive materials for sampling calorimeters. Silicon sensors have very high efficiency for charged particles. However, their sensitivity to photons, which comprise a large fraction of the electromagnetic shower, is limited. To enhance the efficiency of detecting photons, materials with higher atomic numbers than silicon are preferable. In this paper we present test beam measurements with a Cadmium-Telluride (CdTe) sensor as the active element of a secondary emission calorimeter with focus on the timing performance of the detector. A Schottky type CdTe sensor with an active area of 1cm2 and a thickness of 1 mm is used in an arrangement with tungsten and lead absorbers. Measurements are performed with electron beams in the energy range from 2 GeV to 200 GeV. A timing resolution of 20 ps is achieved under the best conditions.

  14. Selective and low temperature transition metal intercalation in layered tellurides

    Science.gov (United States)

    Yajima, Takeshi; Koshiko, Masaki; Zhang, Yaoqing; Oguchi, Tamio; Yu, Wen; Kato, Daichi; Kobayashi, Yoji; Orikasa, Yuki; Yamamoto, Takafumi; Uchimoto, Yoshiharu; Green, Mark A.; Kageyama, Hiroshi

    2016-01-01

    Layered materials embrace rich intercalation reactions to accommodate high concentrations of foreign species within their structures, and find many applications spanning from energy storage, ion exchange to secondary batteries. Light alkali metals are generally most easily intercalated due to their light mass, high charge/volume ratio and in many cases strong reducing properties. An evolving area of materials chemistry, however, is to capture metals selectively, which is of technological and environmental significance but rather unexplored. Here we show that the layered telluride T2PTe2 (T=Ti, Zr) displays exclusive insertion of transition metals (for example, Cd, Zn) as opposed to alkali cations, with tetrahedral coordination preference to tellurium. Interestingly, the intercalation reactions proceed in solid state and at surprisingly low temperatures (for example, 80 °C for cadmium in Ti2PTe2). The current method of controlling selectivity provides opportunities in the search for new materials for various applications that used to be possible only in a liquid. PMID:27966540

  15. Development of a cadmium telluride pixel detector for astrophysical applications

    Science.gov (United States)

    Miyasaka, Hiromasa; Harrison, Fiona A.; Cook, Walter R.; Mao, Peter H.; Rana, Vikram R.; Ishikawa, Shin-Nosuke; Ushio, Masayoshi; Aono, Hiroyuki; Watanabe, Shin; Sato, Goro; Kokubun, Motohide; Takahashi, Tadayuki

    2009-08-01

    We are developing imaging Cadmium Telluride (CdTe) pixel detectors optimized for astrophysical hard X-ray applications. Our hybrid detector consist of a CdTe crystal 1mm thick and 2cm × 2cm in area with segmented anode contacts directly bonded to a custom low-noise application specific integrated circuit (ASIC). The CdTe sensor, fabricated by ACRORAD (Okinawa, Japan), has Schottky blocking contacts on a 605 micron pitch in a 32 × 32 array, providing low leakage current and enabling readout of the anode side. The detector is bonded using epoxy-gold stud interconnects to a custom low noise, low power ASIC circuit developed by Caltech's Space Radiation Laboratory. We have achieved very good energy resolution over a wide energy range (0.62keV FWHM @ 60keV, 10.8keV FWHM @ 662keV). We observe polarization effects at room temperature, but they are suppressed if we operate the detector at or below 0°C degree. These detectors have potential application for future missions such as the International X-ray Observatory (IXO).

  16. Thin-film solar cells

    International Nuclear Information System (INIS)

    Aberle, Armin G.

    2009-01-01

    The rapid progress that is being made with inorganic thin-film photovoltaic (PV) technologies, both in the laboratory and in industry, is reviewed. While amorphous silicon based PV modules have been around for more than 20 years, recent industrial developments include the first polycrystalline silicon thin-film solar cells on glass and the first tandem solar cells based on stacks of amorphous and microcrystalline silicon films ('micromorph cells'). Significant thin-film PV production levels are also being set up for cadmium telluride and copper indium diselenide.

  17. Symptomatic zinc deficiency in experimental zinc deprivation.

    OpenAIRE

    Taylor, C M; Goode, H F; Aggett, P J; Bremner, I; Walker, B E; Kelleher, J

    1992-01-01

    An evaluation of indices of poor zinc status was undertaken in five male subjects in whom dietary zinc intake was reduced from 85 mumol d-1 in an initial phase of the study to 14 mumol d-1. One of the subjects developed features consistent with zinc deficiency after receiving the low zinc diet for 12 days. These features included retroauricular acneform macullo-papular lesions on the face, neck, and shoulders and reductions in plasma zinc, red blood cell zinc, neutrophil zinc and plasma alkal...

  18. Radiation resistance of thin-film solar cells for space photovoltaic power

    Science.gov (United States)

    Woodyard, James R.; Landis, Geoffrey A.

    1991-01-01

    Copper indium diselenide, cadmium telluride, and amorphous silicon alloy solar cells have achieved noteworthy performance and are currently being studied for space power applications. Cadmium sulfide cells had been the subject of much effort but are no longer considered for space applications. A review is presented of what is known about the radiation degradation of thin film solar cells in space. Experimental cadmium telluride and amorphous silicon alloy cells are reviewed. Damage mechanisms and radiation induced defect generation and passivation in the amorphous silicon alloy cell are discussed in detail due to the greater amount of experimental data available.

  19. Zinc vanadate nanorods and their visible light photocatalytic activity

    International Nuclear Information System (INIS)

    Pei, L.Z.; Lin, N.; Wei, T.; Liu, H.D.; Yu, H.Y.

    2015-01-01

    Highlights: • Zinc vanadate nanorods have been synthesized by a facile hydrothermal process. • The size of zinc vanadate nanorods can be controlled by growth conditions. • Zinc vanadate nanorods show good photocatalytic activities of methylene blue under solar light. - Abstract: Zinc vanadate nanorods have been synthesized by a simple hydrothermal process using zinc acetate and sodium vanadate as the raw materials. The zinc vanadate nanorods have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM) and solid UV–vis diffuse reflectance spectrum. XRD pattern and HRTEM image show that the zinc vanadate nanorods are composed of single crystalline monoclinic Zn 2 V 2 O 7 phase. SEM and TEM observations show that the diameter and length of the zinc vanadate nanorods are 50–100 nm and about 5 μm, respectively. Sodium dodecyl sulfonate (SDS) has an essential role in the formation of zinc vanadate nanorods. The SDS-assisted nucleation and growth process have been proposed to explain the formation and growth of the zinc vanadate nanorods. Solid UV–vis diffuse reflectance spectrum shows that the zinc vanadate nanorods have a band gap of 2.76 eV. The photocatalytic activities of the zinc vanadate nanorods have been evaluated by the photocatalytic degradation of methylene blue (MB) under solar light irradiation. The MB with the concentration of 10 mg L −1 can be degraded totally under the solar light irradiation for 4 h. It is suggested that the zinc vanadate nanorods exhibit promising application potential for the degradation of organic pollutants under solar light irradiation

  20. Special features of self-compensation of halogen donor action in lead telluride

    International Nuclear Information System (INIS)

    Kajdanov, V.I.; Nemov, S.A.; Ravich, Yu.I.; Dereza, A.Yu.

    1985-01-01

    Specific features of self-compensation of halogen donor action in lead telluride are investigasted. Lead telluride samples with chlorine additions (with tellurium excess) and, besides, with bromine- and iodine additions were studied in order to reveal general regularities in alloyind with all halogen donor impurities. Experimental dependences of the difference between the electron and hole concentrations (n-p) in PbTe as a function of an amount of introduced halogen impurities (Ni) are presented for samples with a maximum compensation at 295 K. General features of the n-p=f(Ni) dependence are presented for all halogens. The hypothesis on the kinetic mechanism of increasing the efficiency of self-compensation of halogen donor action in lead telluride is suggested

  1. Current transport mechanisms in mercury cadmium telluride diode

    Energy Technology Data Exchange (ETDEWEB)

    Gopal, Vishnu, E-mail: vishnu-46@yahoo.com, E-mail: wdhu@mail.sitp.ac.cn [Institute of Defence Scientists and Technologists, CFEES Complex, Brig. S. K. Majumdar Marg, Delhi 110054 (India); Li, Qing; He, Jiale; Hu, Weida, E-mail: vishnu-46@yahoo.com, E-mail: wdhu@mail.sitp.ac.cn [National Lab for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083 (China); He, Kai; Lin, Chun [Key Laboratory of Infrared Imaging Materials and Detectors, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083 (China)

    2016-08-28

    This paper reports the results of modelling of the current-voltage characteristics (I-V) of a planar mid-wave Mercury Cadmium Telluride photodiode in a gate controlled diode experiment. It is reported that the diode exhibits nearly ideal I-V characteristics under the optimum surface potential leading to the minimal surface leakage current. Deviations from the optimum surface potential lead to non ideal I–V characteristics, indicating a strong relationship between the ideality factor of the diode with its surface leakage current. Diode's I–V characteristics have been modelled over a range of gate voltages from −9 V to −2 V. This range of gate voltages includes accumulation, flat band, and depletion and inversion conditions below the gate structure of the diode. It is shown that the I–V characteristics of the diode can be very well described by (i) thermal diffusion current, (ii) ohmic shunt current, (iii) photo-current due to background illumination, and (iv) excess current that grows by the process of avalanche multiplication in the gate voltage range from −3 V to −5 V that corresponds to the optimum surface potential. Outside the optimum gate voltage range, the origin of the excess current of the diode is associated with its high surface leakage currents. It is reported that the ohmic shunt current model applies to small surface leakage currents. The higher surface leakage currents exhibit a nonlinear shunt behaviour. It is also shown that the observed zero-bias dynamic resistance of the diode over the entire gate voltage range is the sum of ohmic shunt resistance and estimated zero-bias dynamic resistance of the diode from its thermal saturation current.

  2. Dissolution kinetics of lead telluride in alkali solutions of hydrogen peroxide

    International Nuclear Information System (INIS)

    Danilova, M.G.; Sveshnikova, L.L.; Stavitskaya, T.A.; Repinskij, S.M.

    1991-01-01

    Dissolution kinetics of lead telluride in alkali solutions of hydrogen peroxide was investigated. Dependences of change of PbTe dissolution rate on concentration of hydrogen peroxide and alkali in the solution were obtained. It is shown that dissolution rate of lead telluride is affected by dissolution rate of lead oxide, representing the product of ReTe dissolution. The obtained regularities can be explained by change of solution structure with increase of KOH concentration and by the state of hydrogen peroxide in the solution

  3. Simulation of core-level binding energy shifts in germanium-doped lead telluride crystals

    International Nuclear Information System (INIS)

    Zyubin, A.S.; Dedyulin, S.N.; Yashina, L.V.; Shtanov, V.I.

    2007-01-01

    To simulate the changes in core-level binding energies in germanium-doped lead telluride, cluster calculations of the changes in the electrostatic potential at the corresponding centers have been performed. Different locations of the Ge atom in the crystal bulk have been considered: near vacancies, near another dopant site, and near the surface. For calculating the potential in the clusters that model the bulk and the surface of the lead telluride crystal (c-PbTe), the electron density obtained in the framework of the Hartree-Fock and hybrid density functional theory (DFT) methods has been used [ru

  4. Solar Energy and Telemedicine in West Africa : A strategic solution

    OpenAIRE

    Ihuoma, Phineese

    2011-01-01

    It is important to bring medical help to those living in West Africa. A good way to do this is by telemedicine. Telemedicine, although it uses power, can be achieved easily with solar panels, and the best solar panels are monocrystalline and cadmium telluride. Using graphical scenarios, statistical derivations, theoretical ideologies acquired from literature reviews, usability ideas and two personal case scenarios, the objective of this project was achieved. Criteria like cost, temperatur...

  5. Post-CMOS FinFET integration of bismuth telluride and antimony telluride thin-film-based thermoelectric devices on SoI substrate

    KAUST Repository

    Aktakka, Ethem Erkan

    2013-10-01

    This letter reports, for the first time, heterogeneous integration of bismuth telluride (Bi2Te3) and antimony telluride (Sb 2Te3) thin-film-based thermoelectric ffect transistors) via a characterized TE-film coevaporationand shadow-mask patterning process using predeposition surface treatment methods for reduced TE-metal contact resistance. As a demonstration vehicle, a 2 × 2 mm2-sized integrated planar thermoelectric generator (TEG) is shown to harvest 0.7 μ W from 21-K temperature gradient. Transistor performance showed no significant change upon post-CMOS TEG integration, indicating, for the first time, the CMOS compatibility of the Bi2Te3 and Sb2Te3 thin films, which could be leveraged for realization of high-performance integrated micro-TE harvesters and coolers. © 2013 IEEE.

  6. Zinc Signals and Immunity.

    Science.gov (United States)

    Maywald, Martina; Wessels, Inga; Rink, Lothar

    2017-10-24

    Zinc homeostasis is crucial for an adequate function of the immune system. Zinc deficiency as well as zinc excess result in severe disturbances in immune cell numbers and activities, which can result in increased susceptibility to infections and development of especially inflammatory diseases. This review focuses on the role of zinc in regulating intracellular signaling pathways in innate as well as adaptive immune cells. Main underlying molecular mechanisms and targets affected by altered zinc homeostasis, including kinases, caspases, phosphatases, and phosphodiesterases, will be highlighted in this article. In addition, the interplay of zinc homeostasis and the redox metabolism in affecting intracellular signaling will be emphasized. Key signaling pathways will be described in detail for the different cell types of the immune system. In this, effects of fast zinc flux, taking place within a few seconds to minutes will be distinguish from slower types of zinc signals, also designated as "zinc waves", and late homeostatic zinc signals regarding prolonged changes in intracellular zinc.

  7. Remote plasma deposition of textured zinc oxide with focus on thin film solar cell applications : material properties, plasma processes and film growth

    NARCIS (Netherlands)

    Groenen, R.

    2005-01-01

    Simultaneously possessing transparency in the visible region, close to that of insulators, and electrical conductivity, close to that of metals, transparent conducting oxide (TCO) thin films form a highly attractive class of materials for a wide variety of applications like thin film solar cells,

  8. Zinc Porphyrins Possessing Three p-Carboxyphenyl Groups: Effect of the Donor Strength of Push-Groups on the Efficiency of Dye Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Ram B. Ambre

    2016-06-01

    Full Text Available Zinc porphyrins decorated with three p-carboxyphenyl anchoring groups and various “push” substituents of varied electron-donating strengths were prepared in good yields by facile and straightforward ways. The effect of electron-donating strength of the donor molecules on the overall power conversion efficiency was evaluated with the help of photophysical, electrochemical, photovoltaic spectroscopy and quantum chemical calculations. It is observed from the photophysical and Infrared (IR spectroscopic data that multi-anchoring dyes are more stable and bind more strongly to the TiO2 surface than their one-anchor counterparts. The properties like a three-step synthesis, high overall yields, possible mass production on a gram-scale and strong binding affinities with TiO2 surfaces make them a suitable choice for commercial applications. Zn1NH3A, with electron donating and anti-aggregation characteristics, achieved the highest efficiency of 6.50%.

  9. Production of zinc pellets

    Science.gov (United States)

    Cooper, J.F.

    1996-11-26

    Uniform zinc pellets are formed for use in batteries having a stationary or moving slurry zinc particle electrode. The process involves the cathodic deposition of zinc in a finely divided morphology from battery reaction product onto a non-adhering electrode substrate. The mossy zinc is removed from the electrode substrate by the action of gravity, entrainment in a flowing electrolyte, or by mechanical action. The finely divided zinc particles are collected and pressed into pellets by a mechanical device such as an extruder, a roller and chopper, or a punch and die. The pure zinc pellets are returned to the zinc battery in a pumped slurry and have uniform size, density and reactivity. Applications include zinc-air fuel batteries, zinc-ferricyanide storage batteries, and zinc-nickel-oxide secondary batteries. 6 figs.

  10. Numerical study of the influence of ZnTe thickness on CdS/ZnTe solar cell performance

    Science.gov (United States)

    Skhouni, Othmane; El Manouni, Ahmed; Mari, Bernabe; Ullah, Hanif

    2016-05-01

    At present most of II-VI semiconductor based solar cells use the CdTe material as an absorber film. The simulation of its performance is realized by means of various numerical modelling programs. We have modelled a solar cell based on zinc telluride (ZnTe) thin film as absorber in substitution to the CdTe material, which contains the cadmium element known by its toxicity. The performance of such photovoltaic device has been numerically simulated and the thickness of the absorber layer has been optimized to give the optimal conversion efficiency. A photovoltaic device consisting of a ZnTe layer as absorber, CdS as the buffer layer and ZnO as a window layer was modelled through Solar Cell Capacitance Simulator Software. Dark and illuminated I-V characteristics and the results for different output parameters of ZnO/CdS/ZnTe solar cell were analyzed. The effect of ZnTe absorber thickness on different main working parameters such as: open-circuit voltage Voc, short-circuit current density Jsc, fill factor FF, photovoltaic conversion efficiency η was intensely studied in order to optimize ZnTe film thickness. This study reveals that increasing the thickness of ZnTe absorber layer results in higher efficiency until a maximum value and then decreases slightly. This maximum was found to be 10% at ZnTe optimum thickness close to 2 µm. Contribution to the topical issue "Materials for Energy Harvesting, Conversion and Storage (ICOME 2015) - Elected submissions", edited by Jean-Michel Nunzi, Rachid Bennacer and Mohammed El Ganaoui

  11. Spectrometry of X-ray beams using Cadmium and Zinc Teluride detector

    International Nuclear Information System (INIS)

    Becker, Paulo Henriques Bastos

    1997-06-01

    Determination of X-ray spectra to be utilized for medical diagnostics is a complementary process to the development of procedures to be applied to the quality control of radiodiagnostics X-ray equipment. Until some years ago, that was only possible using Germanium or Silicon detectors. Both have an excellent resolution in this energy range, but present also some restrictions as there are high costs and the necessity of operating them at temperature of liquid Nitrogen, which is not always available at the measurement's place. Room temperature detectors like Cadmium Telluride and Mercury Iodine don't have these restrictions. They, however, have a lower resolution and incomplete collection of the charges produced by their interaction with radiation. With technological advance of crystal growth in general and new techniques like cooling the crystal with a Peltier cell and rise time discrimination circuits, today Cadmium Telluride detectors show a resolution very close to that from Germanium detectors. This work relates to the routine use of Cadmium and Zinc Telluride detectors for measuring X-ray spectra in loco of diagnostic X-ray units. It characterizes the properties of a commercially available detector and offers a model for stripping the measured pulse height distribution. It was also developed a collimator to allow the direct measurement of the beam. The model developed and the constructed set-up were applied to two X-ray tubes and the achieved spectra compared with some spectra available from the literature. (author)

  12. Effect of zinc addition on properties of cadmium sulfide layer and performance of Cu(In,Ga)Se{sub 2} solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Dowon, E-mail: bae.dowon@yahoo.co.kr; Gho, Junghwan; Shin, Minjung; Kwon, Sehan

    2013-05-01

    Cd{sub (1−x)}Zn{sub x}S (CdS:Zn) thin films were grown on an indium tin oxide-coated glass substrate and Cu(In,Ga)Se{sub 2} (CIGS) surface by chemical bath deposition for solar cell applications, and their composition, and optical properties were studied to decide the optimum process conditions for buffer layer growth. The average conversion efficiency of CIGS solar panels (24-in.) with the CdS:Zn layer was 0.35% higher than that of conventional solar panels mainly because of the increased open-circuit voltage. This efficiency improvement was not due to modification of the optical properties of the buffer layer, but due to the change in the deposition rate during buffer layer growth. - Highlights: ► CdS:Zn buffer layers were fabricated for Cu(In,Ga)Se{sub 2} (CIGS) photovoltaic (PV) panels. ► Composition of buffer layers on indium–tin–oxide (ITO) and CIGS was investigated. ► Transmittance of CdS:Zn on ITO coated glass showed 5% higher than CdS. ► Efficiency of CdS:Zn solution adopted panels showed 0.47% higher than that with CdS. ► However, it was revealed that only Cd and S ions were found at the surface of CIGS.

  13. Effect of zinc addition on properties of cadmium sulfide layer and performance of Cu(In,Ga)Se2 solar cell

    International Nuclear Information System (INIS)

    Bae, Dowon; Gho, Junghwan; Shin, Minjung; Kwon, Sehan

    2013-01-01

    Cd (1−x) Zn x S (CdS:Zn) thin films were grown on an indium tin oxide-coated glass substrate and Cu(In,Ga)Se 2 (CIGS) surface by chemical bath deposition for solar cell applications, and their composition, and optical properties were studied to decide the optimum process conditions for buffer layer growth. The average conversion efficiency of CIGS solar panels (24-in.) with the CdS:Zn layer was 0.35% higher than that of conventional solar panels mainly because of the increased open-circuit voltage. This efficiency improvement was not due to modification of the optical properties of the buffer layer, but due to the change in the deposition rate during buffer layer growth. - Highlights: ► CdS:Zn buffer layers were fabricated for Cu(In,Ga)Se 2 (CIGS) photovoltaic (PV) panels. ► Composition of buffer layers on indium–tin–oxide (ITO) and CIGS was investigated. ► Transmittance of CdS:Zn on ITO coated glass showed 5% higher than CdS. ► Efficiency of CdS:Zn solution adopted panels showed 0.47% higher than that with CdS. ► However, it was revealed that only Cd and S ions were found at the surface of CIGS

  14. Carrier Transport, Recombination, and the Effects of Grain Boundaries in Polycrystalline Cadmium Telluride Thin Films for Photovoltaics

    Science.gov (United States)

    Tuteja, Mohit

    Cadmium Telluride (CdTe), a chalcogenide semiconductor, is currently used as the absorber layer in one of the highest efficiency thin film solar cell technologies. Current efficiency records are over 22%. In 2011, CdTe solar cells accounted for 8% of all solar cells installed. This is because, in part, CdTe has a low degradation rate, high optical absorption coefficient, and high tolerance to intrinsic defects. Solar cells based on polycrystalline CdTe exhibit a higher short-circuit current, fill factor, and power conversion efficiency than their single crystal counterparts. This is despite the fact that polycrystalline CdTe devices exhibit lower open-circuit voltages. This is contrary to the observation for silicon and III-V semiconductors, where material defects cause a dramatic drop in device performance. For example, grain boundaries in covalently-bonded semiconductors (a) act as carrier recombination centers, and (b) lead to localized energy states, causing carrier trapping. Despite significant research to date, the mechanism responsible for the superior current collection properties of polycrystalline CdTe solar cells has not been conclusively answered. This dissertation focuses on the macro-scale electronic band structure, and micro scale electronic properties of grains and grain boundaries in device-grade CdTe thin films to answer this open question. My research utilized a variety of experimental techniques. Samples were obtained from leading groups fabricating the material and devices. A CdCl 2 anneal is commonly performed as part of this fabrication and its effects were also investigated. Photoluminescence (PL) spectroscopy was employed to study the band structure and defect states in CdTe polycrystals. Cadmium vacancy- and chlorine-related states lead to carrier recombination, as in CdTe films grown by other methods. Comparing polycrystalline and single crystal CdTe, showed that the key to explaining the improved performance of polycrystalline CdTe does

  15. Quantum dot solar cell

    International Nuclear Information System (INIS)

    Ahamefula, U.C.; Sulaiman, M.Y.; Sopian, K.; Ibarahim, Z.; Ibrahim, N.; Alghoul, M.A.; Haw, L.C.; Yahya, M.; Amin, N.; Mat, S.; Ruslan, M.H.

    2009-01-01

    Full text: The much awaited desire of replacing fossil fuel with photovoltaic will remain a fairy tale if the myriad of issues facing solar cell development are marginalized. Foremost in the list is the issue of cost. Silicon has reached a stage where its use on large scale can no longer be lavishly depended upon. The demand for high grade silicon from the microelectronics and solar industries has soared leading to scarcity. New approach has to be sought. Notable is the increased attention on thin films such as cadmium telluride, copper indium gallium diselenide, amorphous silicon, and the not so thin non-crystalline family of silicon. While efforts to address the issues of stability, toxicity and efficiency of these systems are ongoing, another novel approach is quietly making its appearance - quantum dots. Quantum dots seem to be promising candidates for solar cells because of the opportunity to manipulate their energy levels allowing absorption of a wider solar spectrum. Utilization of minute quantity of these nano structures is enough to bring the cost of solar cell down and to ascertain sustainable supply of useful material. The paper outlines the progress that has been made on quantum dot solar cells. (author)

  16. Indium telluride nanotubes: Solvothermal synthesis, growth mechanism, and properties

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Liyan [National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093 (China); Yan, Shancheng, E-mail: yansc@njupt.edu.cn [National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093 (China); School of Geography and Biological Information, Nanjing University of Posts and Telecommunications, Nanjing 210046 (China); Lu, Tao; Shi, Yi; Wang, Jianyu [National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093 (China); Yang, Fan [School of Geography and Biological Information, Nanjing University of Posts and Telecommunications, Nanjing 210046 (China)

    2014-03-15

    hydrogen storage, compared with the nanowires. The nanotube device also has a broad light detection range from 300 nm to 1100 nm, covering the UV–visible–NIR region. This good performance of In{sub 2}Te{sub 3} nanotubes may enable significant advancements of new photodetection and photosensing applications. Highlights: • The In{sub 2}Te{sub 3} nanotube device also has a broad light detection range from 300 nm to 1100 nm. • The nanotube is 137.85 m{sup 2} g{sup −1}, which makes it suitable for gas sensing and hydrogen storage. • A possible growth mechanism of the indium telluride nanotubes was proposed. • In addition, no In{sub 2}Te{sub 3} nanotubes have been reported until now.

  17. On the origin of the changes in the opto-electrical properties of boron-doped zinc oxide films after plasma surface treatment for thin-film silicon solar cell applications

    Science.gov (United States)

    Le, Anh Huy Tuan; Kim, Youngkuk; Lee, Youn-Jung; Hussain, Shahzada Qamar; Nguyen, Cam Phu Thi; Lee, Jaehyung; Yi, Junsin

    2018-03-01

    The modification of the steep and sharp valleys on the surface of the boron-doped zinc oxide (BZO) front electrodes by plasma surface treatment is a critical process for avoiding a significant reduction in the electrical performance of thin-film silicon solar cells. In this work, we report the origin of the changes in the electrical and optical properties of the BZO films that occur after this process. On the basis of an analysis of the chemical states, we found an improvement of the carrier concentration along with the treatment time that was mainly due to an increase of the oxygen vacancy. This indicated a deficiency of the oxygen in the BZO films under argon-ion bombardment. The red-shift of the A1 longitudinal optical mode frequency in the Raman spectra that was attributed to the existence of vacancy point defects within the films also strengthened this argument. The significant reduction of the haze ratio as well as the appearance of interference peaks on the transmittance spectra as the treatment time was increased were mainly due to the smoothing of the film surface, which indicated a degradation of the light-scattering capability of the BZO films. We also observed a gain of the visible-region transmittance that was attributed to the decrease of the thickness of the BZO films after the plasma surface treatment, instead of the crystallinity improvement. On the basis of our findings, we have proposed a further design rule of the BZO front electrodes for thin-film silicon solar cell applications.

  18. Controlling the directionality of charge transfer in phthalocyaninato zinc sensitizer for a dye-sensitized solar cell: density functional theory studies.

    Science.gov (United States)

    Wan, Liang; Qi, Dongdong; Zhang, Yuexing; Jiang, Jianzhuang

    2011-01-28

    Density functional theory (DFT) calculation on the molecular structures, charge distribution, molecular orbitals, electronic absorption spectra of a series of eight unsymmetrical phthalocyaninato zinc complexes with one peripheral (E)-2-cyano-3-(5-vinylthiophen-2-yl) acrylic acid substituent at 2 or 3 position as an electron-withdrawing group and a different number of electron-donating amino groups at the remaining peripheral positions (9, 10, 16, 17, 23, 24) of the phthalocyanine ring, namely ZnPc-β-A, ZnPc-β-A-I-NH(2), ZnPc-β-A-II-NH(2), ZnPc-β-A-III-NH(2), ZnPc-β-A-I,II-NH(2), ZnPc-β-A-I,III-NH(2), ZnPc-β-A-II,III-NH(2), and ZnPc-β-A-I,II,III-NH(2), reveals the effects of amino groups on the charge transfer properties of these phthalocyanine derivatives with a typical D-π-A electronic structure. The introduction of amino groups was revealed altering of the atomic charge distribution, lifting the frontier molecular orbital level, red-shift of the near-IR bands in the electronic absorption spectra, and finally resulting in enhanced charge transfer directionality for the phthalocyanine compounds. Along with the increase of the peripheral amino groups at the phthalocyanine ring from 0, 2, 4, to 6, the dihedral angle between the phthalocyanine ring and the average plane of the (E)-2-cyano-3-(5-vinylthiophen-2-yl) acrylic acid substituent increases from 0 to 3.3° in an irregular manner. This is in good contrast to the regular and significant change in the charge distribution, destabilization of frontier orbital energies, and red shift of near-IR bands of phthalocyanine compounds along the same order. In addition, comparative studies indicate the smaller effect of incorporating two amino groups onto the 16 and 17 than on 9 and 10 or 23 and 24 peripheral positions of the phthalocyanine ring onto the aforementioned electronic properties, suggesting the least effect on tuning the charge transfer property of the phthalocyanine compound via introducing two

  19. Dietary phytate, zinc and hidden zinc deficiency.

    Science.gov (United States)

    Sandstead, Harold H; Freeland-Graves, Jeanne H

    2014-10-01

    Epidemiological data suggest at least one in five humans are at risk of zinc deficiency. This is in large part because the phytate in cereals and legumes has not been removed during food preparation. Phytate, a potent indigestible ligand for zinc prevents it's absorption. Without knowledge of the frequency of consumption of foods rich in phytate, and foods rich in bioavailable zinc, the recognition of zinc deficiency early in the illness may be difficult. Plasma zinc is insensitive to early zinc deficiency. Serum ferritin concentration≤20μg/L is a potential indirect biomarker. Early effects of zinc deficiency are chemical, functional and may be "hidden". The clinical problem is illustrated by 2 studies that involved US Mexican-American children, and US premenopausal women. The children were consuming home diets that included traditional foods high in phytate. The premenopausal women were not eating red meat on a regular basis, and their consumption of phytate was mainly from bran breakfast cereals. In both studies the presence of zinc deficiency was proven by functional responses to controlled zinc treatment. In the children lean-mass, reasoning, and immunity were significantly affected. In the women memory, reasoning, and eye-hand coordination were significantly affected. A screening self-administered food frequency questionnaire for office might help caregiver's identify patients at risk of zinc deficiency. Copyright © 2014 Elsevier GmbH. All rights reserved.

  20. Zinc stannate nanostructures: hydrothermal synthesis

    International Nuclear Information System (INIS)

    Baruah, Sunandan; Dutta, Joydeep

    2011-01-01

    Nanostructured binary semiconducting metal oxides have received much attention in the last decade owing to their unique properties rendering them suitable for a wide range of applications. In the quest to further improve the physical and chemical properties, an interest in ternary complex oxides has become noticeable in recent times. Zinc stannate or zinc tin oxide (ZTO) is a class of ternary oxides that are known for their stable properties under extreme conditions, higher electron mobility compared to its binary counterparts and other interesting optical properties. The material is thus ideal for applications from solar cells and sensors to photocatalysts. Among the different methods of synthesizing ZTO nanostructures, the hydrothermal method is an attractive green process that is carried out at low temperatures. In this review, we summarize the conditions leading to the growth of different ZTO nanostructures using the hydrothermal method and delve into a few of its applications reported in the literature. (topical review)

  1. Optimization of aluminum-doped zinc oxide films deposited at low temperature by radio-frequency sputtering on flexible substrates for solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, S. [Departamento de Energias Renovables, Energia Solar Fotovoltaica, Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT), Avda. Complutense 22, 28040 Madrid (Spain); Naranjo, F.B. [Grupo de Ingenieria Fotonica (GRIFO), Departamento de Electronica, Escuela Politecnica Superior, Universidad de Alcala, Campus Universitario, 28871 Alcala de Henares, Madrid (Spain)

    2010-02-15

    Aluminum-doped zinc oxide films were deposited at 100 C on polyethylene terephthalate by radio-frequency magnetron sputtering. The sputtering parameters such as RF power and Argon working pressure were varied from 25 to 125 W and from 1.1 to 0.2 Pa, respectively. The structural properties of as-deposited films were analysed by X-ray diffraction, showing that all the deposited films were polycrystalline, with hexagonal structure and a strong preferred c-axis orientation (0 0 2). Full width at half maximum and grain sizes were around 0.27 and ranged from 24 to 32 nm, respectively. The strain state of the samples was also estimated from X-ray diffraction measurements, obtaining compressive stresses from 0.29 to 0.05 GPa. Resistivity as low as 1.1 x 10{sup -3} {omega} cm was achieved for the film deposited at 75 W and 0.2 Pa, sample that showed a low strain state of -0.06 GPa. High optical transmittance ({proportional_to}80%) was exhibited when films were deposited at RF powers below 100 W. Band gap energies ranged from 3.36 to 3.39 eV and a refractive index of 1.80{+-}0.05, constant in the visible region, was also obtained. (author)

  2. Electrochemical synthesis and characterization of zinc carbonate and zinc oxide nanoparticles

    Science.gov (United States)

    Pourmortazavi, Seied Mahdi; Marashianpour, Zahra; Karimi, Meisam Sadeghpour; Mohammad-Zadeh, Mohammad

    2015-11-01

    Zinc oxide and its precursor i.e., zinc carbonate is widely utilized in various fields of industry, especially in solar energy conversion, optical, and inorganic pigments. In this work, a facile and clean electrodeposition method was utilized for the synthesis of zinc carbonate nanoparticles. Also, zinc oxide nanoparticles were produced by calcination of the prepared zinc carbonate powder. Zinc carbonate nanoparticles with different sizes were electrodeposited by electrolysis of a zinc plate as anode in the solution of sodium carbonate. It was found that the particle size of zinc carbonate might be tuned by process parameters, i.e., electrolysis voltage, carbonate ion concentration, solvent composition and stirring rate of the electrolyte solution. An orthogonal array design was utilized to identify the optimum experimental conditions. The experimental results showed that the minimum size of the electrodeposited ZnCO3 particles is about 24 nm whereas the maximum particle size is around 40 nm. The TG-DSC studies of the nanoparticles indicated that the main thermal degradation of ZnCO3 occurs in two steps over the temperature ranges of 150-250 and 350-400 °C. The electrosynthesized ZnCO3 nanoparticles were calcined at the temperature of 600 °C to prepare ZnO nanoparticles. The prepared ZnCO3 and ZnO nanoparticles were characterized by SEM, X-ray diffraction (XRD), and FT-IR techniques.

  3. Fullerene derivative-doped zinc oxide nanofilm as the cathode of inverted polymer solar cells with low-bandgap polymer (PTB7-Th) for high performance.

    Science.gov (United States)

    Liao, Sih-Hao; Jhuo, Hong-Jyun; Cheng, Yu-Shan; Chen, Show-An

    2013-09-14

    Modification of a ZnO cathode by doping it with a hydroxyl-containing derivative - giving a ZnO-C60 cathode - provides a fullerene-derivative-rich surface and enhanced electron conduction. Inverted polymer solar cells with the ZnO-C60 cathode display markedly improved power conversion efficiency compared to those with a pristine ZnO cathode, especially when the active layer includes the low-bandgap polymer PTB7-Th. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. BWR zinc addition Sourcebook

    International Nuclear Information System (INIS)

    Garcia, Susan E.; Giannelli, Joseph F.; Jarvis, Alfred J.

    2014-01-01

    Boiling Water Reactors (BWRs) have been injecting zinc into the primary coolant via the reactor feedwater system for over 25 years for the purpose of controlling primary system radiation fields. The BWR zinc injection process has evolved since the initial application at the Hope Creek Nuclear Station in 1986. Key transitions were from the original natural zinc oxide (NZO) to depleted zinc oxide (DZO), and from active zinc injection of a powdered zinc oxide slurry (pumped systems) to passive injection systems (zinc pellet beds). Zinc addition has continued through various chemistry regimes changes, from normal water chemistry (NWC) to hydrogen water chemistry (HWC) and HWC with noble metals (NobleChem™) for mitigation of intergranular stress corrosion cracking (IGSCC) of reactor internals and primary system piping. While past reports published by the Electric Power Research Institute (EPRI) document specific industry experience related to these topics, the Zinc Sourcebook was prepared to consolidate all of the experience gained over the past 25 years. The Zinc Sourcebook will benefit experienced BWR Chemistry, Operations, Radiation Protection and Engineering personnel as well as new people entering the nuclear power industry. While all North American BWRs implement feedwater zinc injection, a number of other BWRs do not inject zinc. This Sourcebook will also be a valuable resource to plants considering the benefits of zinc addition process implementation, and to gain insights on industry experience related to zinc process control and best practices. This paper presents some of the highlights from the Sourcebook. (author)

  5. Method of capturing or trapping zinc using zinc getter materials

    Science.gov (United States)

    Hunyadi Murph, Simona E.; Korinko, Paul S.

    2017-07-11

    A method of trapping or capturing zinc is disclosed. In particular, the method comprises a step of contacting a zinc vapor with a zinc getter material. The zinc getter material comprises nanoparticles and a metal substrate.

  6. Theoretical investigation of the charge-transfer properties in different meso-linked zinc porphyrins for highly efficient dye-sensitized solar cells.

    Science.gov (United States)

    Namuangruk, Supawadee; Sirithip, Kanokkorn; Rattanatwan, Rattanawelee; Keawin, Tinnagon; Kungwan, Nawee; Sudyodsuk, Taweesak; Promarak, Vinich; Surakhot, Yaowarat; Jungsuttiwong, Siriporn

    2014-06-28

    The charge transfer effect of different meso-substituted linkages on porphyrin analogue 1 (A1, B1 and C1) was theoretically investigated using density functional theory (DFT) and time-dependent DFT (TDDFT) calculations. The calculated geometry parameters and natural bond orbital analysis reveal that the twisted conformation between porphyrin macrocycle and meso-substituted linkages leads to blocking of the conjugation of the conjugated backbone, and the frontier molecular orbital plot shows that the intramolecular charge transfer of A1, B1 and C1 hardly takes place. In an attempt to improve the photoinduced intramolecular charge transfer ability of the meso-linked zinc porphyrin sensitizer, a strong electron-withdrawing group (CN) was introduced into the anchoring group of analogue 1 forming analogue 2 (A2, B2 and C2). The density difference plot of A2, B2 and C2 shows that the charge transfer properties dramatically improved. The electron injection process has been performed using TDDFT; the direct charge-transfer transition in the A2-(TiO2)38 interacting system takes place; our results strongly indicated that introducing electron-withdrawing groups into the acceptor part of porphyrin dyes can fine-tune the effective conjugation length of the π-spacer and improve intramolecular charge transfer properties, consequently inducing the electron injection process from the anchoring group of the porphyrin dye to the (TiO2)38 surface which may improve the conversion efficiency of the DSSCs. Our calculated results can provide valuable information and a promising outlook for computation-aided sensitizer design with anticipated good properties in further experimental synthesis.

  7. Mechanism of manganese (mono and di) telluride thin-film formation and properties

    Science.gov (United States)

    Sharma, Raj Kishore; Singh, Gurmeet; Shul, Yong Gun; Kim, Hansung

    2007-03-01

    Mechanistic studies on the electrocrystallization of manganese telluride (MnTe) thin film are reported using aqueous acidic solution containing MnSO 4 and TeO 2. Tartaric acid was used for the inhibition of hydrated manganese oxide anodic growth at counter electrode. A detailed study on the mechanistic aspect of electrochemical growth of MnTe using cyclic voltametry is carried out. Conditions for electrochemical growth of manganese mono and di telluride thin films have been reported using cyclic voltammetric scans for Mn 2+, Te 4+ and combined Mn 2+ and Te 4+. X-ray diffraction showed the formation of polycrystalline MnTe films with cubic, hexagonal and orthorhombic mixed phases. MnTe film morphology was studied using scanning electron microscope. Susceptibility and electrical characterization supports the anti-ferromagnetic behavior of the as-deposited MnTe thin film.

  8. Zinc at glutamatergic synapses.

    Science.gov (United States)

    Paoletti, P; Vergnano, A M; Barbour, B; Casado, M

    2009-01-12

    It has long been known that the mammalian forebrain contains a subset of glutamatergic neurons that sequester zinc in their synaptic vesicles. This zinc may be released into the synaptic cleft upon neuronal activity. Extracellular zinc has the potential to interact with and modulate many different synaptic targets, including glutamate receptors and transporters. Among these targets, NMDA receptors appear particularly interesting because certain NMDA receptor subtypes (those containing the NR2A subunit) contain allosteric sites exquisitely sensitive to extracellular zinc. The existence of these high-affinity zinc binding sites raises the possibility that zinc may act both in a phasic and tonic mode. Changes in zinc concentration and subcellular zinc distribution have also been described in several pathological conditions linked to glutamatergic transmission dysfunctions. However, despite intense investigation, the functional significance of vesicular zinc remains largely a mystery. In this review, we present the anatomy and the physiology of the glutamatergic zinc-containing synapse. Particular emphasis is put on the molecular and cellular mechanisms underlying the putative roles of zinc as a messenger involved in excitatory synaptic transmission and plasticity. We also highlight the many controversial issues and unanswered questions. Finally, we present and compare two widely used zinc chelators, CaEDTA and tricine, and show why tricine should be preferred to CaEDTA when studying fast transient zinc elevations as may occur during synaptic activity.

  9. Study of a low power plasma reactor for the synthesis of zinc oxide as window layers in Cu(In,Ga)Se{sub 2} solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Alexandre, E-mail: alexadre.ma@chimie-paristech.fr [Institut de Recherche de Chimie Paris (IRCP), Equipe 2PM (Procédés, Plasmas, Microsystèmes), UMR 8247, Chimie ParisTech-CNRS, 11 Rue Pierre et Marie Curie, 75005 Paris (France); Institute of Research and Development of Photovoltaic Energy (IRDEP), UMR7174, EDF-CNRS-Chimie ParisTech, 6 Quai Watier, 78401 Chatou (France); ADEME (French Environment and Energy Management Agency), 20 avenue du Grésillé, BP 90406, 49004 Angers Cedex 01 (France); Donsanti, Frédérique [Institute of Research and Development of Photovoltaic Energy (IRDEP), UMR7174, EDF-CNRS-Chimie ParisTech, 6 Quai Watier, 78401 Chatou (France); Rousseau, Frédéric; Morvan, Daniel [Institut de Recherche de Chimie Paris (IRCP), Equipe 2PM (Procédés, Plasmas, Microsystèmes), UMR 8247, Chimie ParisTech-CNRS, 11 Rue Pierre et Marie Curie, 75005 Paris (France)

    2015-05-01

    The low power plasma reactor is an original process which allows the deposition of ZnO controlled thickness films from an aqueous precursor solution in a cold plasma only in order to reach high growth rates. The quality of the deposited material (purity, crystallinity, size of the grains…) depends primarily on the interactions in the reactor between the droplets and the plasma. In this study, the parameters of the deposition (composition of the gases, pressure, power, temperature…) were studied and controlled. The doping characteristics are mainly influenced by the concentration of the precursors in the solution and by the method of injection. The final optimizations allowed high growth rates ranging from 0.6 to 1 nm/s. X-ray Diffraction results show a good crystallinity of the deposited layer (würtzite structure). According to the transmittance measurements, the films present a good transparency and a calculated optical gap value ranging between 3.2 and 3.3 eV. This deposition technique using plasma is fast, flexible, low power consuming and easily adaptable. Cu(In,Ga)Se{sub 2} solar cells with a ZnO window layer have successfully been achieved by using the low power plasma reactor and their performances show an efficiency of 11%. - Highlights: • The low power plasma reactor is a very fast and flexible deposition process. • ZnO films are realized from an aqueous nitrate solution in a plasma discharge only. • ZnO films exhibit good properties for the window layer application. • CIGS solar cells present promising performances with an efficiency of 11%.

  10. Synthesis of optimized indium phosphide/zinc sulfide core/shell nanocrystals and titanium dioxide nanotubes for quantum dot sensitized solar cells

    Science.gov (United States)

    Lee, Seungyong

    Synthesis of InP/ZnS core/shell nanocrystals and TiO 2 nanotubes and the optimization study to couple them together were explored for quantum dot sensitized solar cells. Its intrinsic nontoxicity makes the direct band gap InP/ZnS core/shell be one of the most promising semiconductor nanocrystals for optoelectric applications, with the advantage of tuning the optical absorption range in the desired solar spectrum region. Highly luminescent and monodisperse InP/ZnS nanocrystals were synthesized in a non-coordinating solvent. By varying the synthesis scheme, different size InP/ZnS nanocrystals with emission peaks ranging from 520 nm to 620 nm were grown. For the purpose of ensuring air stability, a ZnS shell was grown. The ZnS shell improves the chemical stability in terms of oxidation prevention. Transmission electron microscopy (TEM) image shows that the nanocrystals are highly crystalline and monodisperse. Free-standing TiO2 nanotubes were produced by an anodization method using ammonium fluoride. The free-standing nanotubes were formed under the condition that the chemical dissolution speed associated with fluoride concentration was faster than the speed of Ti oxidation. Highly ordered free-standing anatase form TiO2 nanotubes, which are transformed by annealing at the optimized temperature, are expected to be ideal for coupling with the prepared InP/ZnS nanocrystals. Electrophoretic deposition was carried out to couple the InP/ZnS nanocrystals with the TiO2 nanotubes. Under the adjusted applied voltage condition, the current during the electrophoretic deposition decreased continuously with time. The amount of the deposited nanocrystals was estimated by calculation and the evenly deposited nanocrystals on the TiO2 nanotubes were observed by TEM.

  11. Diagnostic Genesis Features of Au-Ag Selenide-Telluride Mineralization of Western Java Deposits

    Directory of Open Access Journals (Sweden)

    Euis Tintin Yuningsih

    2016-01-01

    Full Text Available DOI: 10.17014/ijog.3.1.67-76The ore mineralogy of the westernmost part of West Java such as Pongkor, Cibaliung, Cikidang, Cikotok, and Cirotan are characterized by the dominance of silver-arsenic-antimony sulfosalt with silver selenides and rarely tellurides over the argentite, whereas the eastern part of West Java including Arinem and Cineam deposits are dominated by silver-gold tellurides. Mineralogy of Se-type deposits at Pongkor, Cikidang, Cibaliung, Cisungsang, and Cirotan and Te-type deposits at Arinem and Cineam shows their different geochemical characteristics. Mineralogical and geochemical differences can be explained by variation of physico-chemical conditions that existed during gold-silver deposition by applying the phase relation among sulfide, telluride, and selenide mineral association in the deposits. The relative values of ƒSe2(g, ƒTe(g, and ƒS2(g control the actual presence of selenide or telluride minerals within the West Java deposits, which also depend on their concentrations in the hydrothermal fluid. Even though the concentration of selenium in the hydrothermal fluid of Te-type deposits might have been similar or even higher than that in the Se-type, early substitution of selenium in the sulfide minerals prevents its concentration in the hydrothermal fluid to the levels for precipitating selenide minerals. Therefore, early sulfide mineral deposition from reduction fluids will not increase the ƒSe2(g/ƒS2(g ratio to form selenide minerals in Te-type deposits of Arinem and Cineam, other than selenium-bearing sulfide mineral such as Se-bearing galena or Se-bearing pyrargyrite-proustite.

  12. Donor impurity self-compensation by neutral complexes in bismuth doped lead telluride

    International Nuclear Information System (INIS)

    Ravich, Yu.I.; Nemov, S.A.; Proshin, V.I.

    1994-01-01

    Self-compensation is calculated of impurity doping action in semiconductors of the A 4 B 6 type by neutral complexes, consisting of a vacancy and two impurity atoms. Complexes entropy is estimated and the thermodynamic potential is minimized in the concentration of single two-charge vacancies and complexes. Calculation results are compared with experimental data, obtained when lead telluride doping by bismuth. Account for complex formation improves agreement theory with experiment. 4 refs., 1 fig

  13. Zinc oxide overdose

    Science.gov (United States)

    Zinc oxide is an ingredient in many products. Some of these are certain creams and ointments used ... prevent or treat minor skin burns and irritation. Zinc oxide overdose occurs when someone eats one of ...

  14. Use of a Soluble Anode in Electrodeposition of Thick Bismuth Telluride Layers

    Science.gov (United States)

    Maas, M.; Diliberto, S.; de Vaulx, C.; Azzouz, K.; Boulanger, C.

    2014-10-01

    Integration of thermoelectric devices within an automotive heat exchanger could enable conversion of lost heat into electrical energy, contributing to improved total output from the engine. For this purpose, synthesis of thick bismuth telluride (Bi2Te3) films is required. Bismuth telluride has been produced by an electrochemical method in nitric acid with a sacrificial bismuth telluride anode as the source of cations. The binary layer grows on the working electrode while the counter-electrode, a Bi2Te3 disk obtained by high frequency melting, is oxidized to BiIII and TeIV. This process leads to auto-regeneration of the solution without modification of its composition. The thickness of films deposited by use of the Bi2Te3 anode was approximately 10 times that without. To demonstrate the utility of a soluble anode in electrochemical deposition, we report characterization of the composition and morphology of the films obtained under different experimental conditions. Perfectly dense and regular Bi2Te3 films (˜400 μm) with low internal stress and uniform composition across the cross-section were prepared. Their thermoelectric properties were assessed.

  15. Zinc and gastrointestinal disease

    Institute of Scientific and Technical Information of China (English)

    Sonja; Skrovanek; Katherine; DiGuilio; Robert; Bailey; William; Huntington; Ryan; Urbas; Barani; Mayilvaganan; Giancarlo; Mercogliano; James; M; Mullin

    2014-01-01

    This review is a current summary of the role that both zinc deficiency and zinc supplementation can play in the etiology and therapy of a wide range of gastrointestinal diseases. The recent literature describing zinc action on gastrointestinal epithelial tight junctions and epithelial barrier function is described. Zinc enhancement of gastrointestinal epithelial barrier function may figure prominently in its potential therapeutic action in several gastrointestinal diseases.

  16. Effects of the position substrate upon the structural behaviour, electrical and optical properties of zinc-oxide films used in solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Bouderbala, M.; Hamzaoui, S.; Stambouli, A.B.; Bouziane, H. [USTO, Lab. de Microscopie Electronique, Oran (Algeria)

    1999-12-01

    The preparation by the rf sputtering technique and characterisation of ZnO thin films used as windows in solar cells are described. The electrical behaviour and structural spectra clearly show an important effect of the substrate position with respect to the target. In fact, among all the studied substrate positions, only the samples facing the target are randomly oriented having the mixed orientation (100), (002) and (101). All the others have the c(002)-axis orientation. The scanning electron-microscope observations confirm the X-ray analysis results. The last samples have a resistivity as low as 10{sup -3} {omega}cm while the randomly-oriented, ones have a large resistivity of about 10{sup 2}-10{sup 3} {omega}cm. These latter show, in their transmittance characteristics, a slight shift towards higher wavelengths. However, no effect is noticed when the other samples are optically assessed. Consequently, the optical gap is found to be about 3.38 eV for the conducting films and 3.3 eV for the ones having a higher resistivity. The average transmittance in the visible range is around 85-90% for all the samples. (Author)

  17. Selenization of Cu2ZnSnS4 Enhanced the Performance of Dye-Sensitized Solar Cells: Improved Zinc-Site Catalytic Activity for I3.

    Science.gov (United States)

    Wang, Xiuwen; Xie, Ying; Bateer, Buhe; Pan, Kai; Jiao, Yanqing; Xiong, Ni; Wang, Song; Fu, Honggang

    2017-11-01

    Cu 2 ZnSnS 4 (CZTS) and Cu 2 ZnSn(S,Se) 4 (CZTSSe) as promising photovoltaic materials have drawn much attention because they are environmentally benign and earth-abundant elements. In this work, the monodispersed, low-cost Cu 2 ZnSnS 4 nanocrystals with small size have been controllably synthesized via a wet chemical routine. And CZTSSe could be easily prepared after selenization of CZTS. When they are employed as counter electrodes (CEs) for dye-sensitized solar cells (DSSCs), the power conversion efficiency (PCE) has been improved from 3.54% to 7.13% as CZTS is converted to CZTSSe, which is also compared to that of Pt (7.62%). The exact reason for the enhanced catalytic activity of I 3 - is discussed with the work function and density functional theory (DFT) when CZTSSe converted from CZTS. The results of a Kelvin probe suggest that the work function of CZTSSe (5.61 eV) is closer to that of Pt (5.65 eV) and higher than that of CZTS, which matched the redox shuttle potential better. According to the theory calculation, all the atomic and bond populations changed significantly when Se replaced partly the S on the CZTS system, especially in the Zn site. During the catalytic process as CEs, the adsorption energy obviously increased compared to those at other sites when I 3 - adsorbed on the Zn site in CZTSSe. So, Zn plays an important role for the reduction of I 3 - after CZTS is converted to CZTSSe. Based on above analysis, the reason for enhanced performance of DSSCs when CZTS converted to CZTSSe is mainly due to the enhancement of Zn-site activity. This work is beneficial for understanding the catalytic reaction mechanism of CZTS(Se) as CEs of DSSCs.

  18. Zinc in human serum

    International Nuclear Information System (INIS)

    Kiilerich, S.

    1987-01-01

    The zinc ion is essential for the living organism. Many pathological conditions have been described as a consequence of zinc deficiency. As zinc constitutes less than 0.01 per cent of the body weight, it conventionally belongs to the group of trace elements. The method of atomic absorption spectrophotometry is used to measure the concentration of zinc in serum and urine from healthy persons. The assumptions of the method is discussed. The importance of proteinbinding, diet and the diurnal variation of serum zinc concentration is presented. Serum versus plasma zinc concentration is discussed. Reference serum zinc values from 104 normal subjects are given. Zinc in serum is almost entirely bound to proteins. A preliminary model for the estimation of the distribution of zinc between serum albumin and α 2 -macroglobulin is set up. This estimate has been examined by an ultracentrufugation method. The binding of zinc to a α 2 -macroglobulin in normal persons is appoximately 7 per cent, in patients with cirrhosis of the liver of alcoholic origin approximately 6 per cent, in patients with insulin dependent diabetes mellitus approximately 5 per cent, and in patients with chronic renal failure approximately 2 per cent. It is concluded, therefore, that for clinical purposes it is sufficient to use the concentration of total serum zinc corrected for the concentration of serum albumin. (author)

  19. Low dose in nuclear cardiology: state of the art in the era of new cadmium-zinc-telluride cameras.

    Science.gov (United States)

    Acampa, Wanda; Buechel, Ronny R; Gimelli, Alessia

    2016-06-01

    The use of myocardial perfusion imaging has seen a tremendous growth during the last decade and has become the most commonly used non-invasive imaging tool for risk stratification in patients with suspected and known coronary artery disease. Adherence to radiation safety best practices varied significantly between laboratories but the possibility to use the new cameras in nuclear cardiology can reduce dramatically the radiation dose without losing accuracy. Moreover, the physical characteristics of ultrafast technology could be able to open new doors for the evaluation of old parameters, changing the impact of nuclear cardiology in the diagnostic strategies. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

  20. An XPS study of bromine in methanol etching and hydrogen peroxide passivation treatments for cadmium zinc telluride radiation detectors

    International Nuclear Information System (INIS)

    Babar, S.; Sellin, P.J.; Watts, J.F.; Baker, M.A.

    2013-01-01

    Highlights: ► CdZnTe single crystal etched in bromine-in-methanol and passivated in H 2 O 2 . ► XPS depth used to accurately determine enriched Te layer and TeO 2 thickness. ► For 0.2 and 2.0 (v/v) % bromine-in-methanol treatments, enriched Te layer thickness determined to be 1.3 and 1.8 nm, respectively. ► After passivation in 30 wt.% H 2 O 2 , the oxide thickness varies between 1.0 and 1.25 nm depending on the calculation method. - Abstract: The performance of single crystal CdZnTe radiation detectors is dependent on both the bulk and the surface properties of the material. After single crystal fabrication and mechanical polishing, modification of the surface to remove damage and reduce the surface leakage current is generally achieved through chemical etching followed by a passivation treatment. In this work, CdZnTe single crystals have been chemically etched using a bromine in methanol (BM) treatment. The BM concentrations employed were 0.2 and 2.0 (v/v) % and exposure times varied between 5 and 120 s. Angle resolved XPS and sputter depth profiling has been employed to characterize the surfaces for the different exposure conditions. A Te rich surface layer was formed for all exposures and the layer thickness was found to be independent of exposure time. The enriched Te layer thickness was accurately determined by calibrating the sputter rate against a CdTe layer of known thickness. For BM concentrations of 0.2 (v/v) % and 2 (v/v) %, the Te layer thickness was determined to be 1.3 ± 0.2 and 1.8 ± 0.2 nm, respectively. The BM etched surfaces have subsequently been passivated in a 30 wt.% H 2 O 2 solution employing exposure time of 15 s. The oxide layer thickness has been calculated using two standard XPS methodologies, based on the Beer–Lambert expression. The TeO 2 thickness calculated from ARXPS data are slightly higher than the thickness obtained by the simplified Beer–Lambert expression. For BM exposures of 30–120 s followed by a passivation treatment of 30 wt. % H 2 O 2 solution employing an exposure time 15 s, the ARXPS method gave an average TeO 2 thickness value of 1.20 nm and the simplified Beer–Lambert expression gave an average thickness value of 0.99 nm.

  1. Cadmium Manganese Telluride (Cd1-xMnxTe): A potential material for room-temperature radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Hossain, A.; Cui, Y.; Bolotnikov, A.; Camarda, G.; Yang, G.; Kim, K-H.; Gul, R.; Xu, L.; Li, L.; Mycielski, A.; and James, R.B.

    2010-07-11

    Cadmium Manganese Telluride (CdMnTe) recently emerged as a promising material for room-temperature X- and gamma-ray detectors. It offers several potential advantages over CdZnTe. Among them is its optimal tunable band gap ranging from 1.7-2.2 eV, and its relatively low (< 50%) content of Mn compared to that of Zn in CdZnTe that assures this favorable band-gap range. Another important asset is the segregation coefficient of Mn in CdTe that is approximately unity compared to 1.35 for Zn in CdZnTe, so ensuring the homogenous distribution of Mn throughout the ingot; hence, a large-volume stoichiometric yield is attained. However, some materials issues primarily related to the growth process impede the production of large, defect-free single crystals. The high bond-ionicity of CdMnTe entails a higher propensity to crystallize into a hexagonal structure rather than to adopt the expected zinc-blend structure, which is likely to generate twins in the crystals. In addition, bulk defects generate in the as-grown crystals due to the dearth of high-purity Mn, which yields a low-resistivity material. In this presentation, we report on our observations of such material defects in current CdMnTe materials, and our evaluation of its potential as an alternative detector material to the well-known CdZnTe detectors. We characterized the bulk defects of several indium- and vanadium-doped Cd1-xMnxTe crystals by using several advanced techniques, viz., micro-scale mapping, white-beam x-ray diffraction/reflection topography, and chemical etching. Thereafter, we fabricated some detectors from selected CdMnTe crystals, characterized their electrical properties, and tested their performance as room-temperature X- and gamma-ray detectors. Our experimental results indicate that CdMnTe materials could well prove to become a viable alternative in the near future.

  2. Cadmium Telluride and Grain Boundaries: A Preliminary Study

    Science.gov (United States)

    Liao, Michael Evan

    The efficacy of the CdCl2 treatment on polycrystalline CdTe-based solar cells was discovered over a quarter of a century ago; and yet, the exact mechanism of this treatment is still not fully understood to this day. In fact, the lack of understanding stems from a debate on the exact role of grain boundaries in CdCl2-treated CdTe solar cells. Some hypothesize that the CdCl2-treatment causes grain boundaries to become beneficial to solar cell performance while others disagree and claim that the treatment simply mitigates the harmful effects of grain boundaries via passivation. A future goal of this project is to determine which, if either, hypothesis is correct by direct wafer bonding single crystalline CdTe. Direct wafer bonding of single crystalline materials would create only one grain boundary at the bonded interface. This approach allows the orientation and surface chemistry of interfaces to be controlled in order to study the chemistry of grain boundaries methodically. However, before any direct wafer bonding can be done, a preliminary study of single crystalline CdTe is necessary. High-quality direct wafer bonding can only be achieved if the surfaces of each wafer satisfy certain requirements. Additionally, analyzing single crystalline CdTe materials prior to bonding is crucial in order to make any insightful connections between results found from direct bonding of single crystalline CdTe and what is observed in polycrystalline CdTe. First, the surface of an (001) CdTe layer epitaxially grown on an (001) InSb substrate is studied using atomic force microscopy. Stacking faults on the CdTe surface are observed and the thickness of the grown CdTe epilayer is calculated by considering the interplanar angles between the (001) and (111) crystallographic planes as well as the dimensions of the stacking faults. While the stacking faults will inhibit successful wafer bonding, the roughness of the regions outside the stacking faults is 0.9 nm, which is an acceptable

  3. Feasibility of preparing patterned molybdenum coatings on bismuth telluride thermoelectric modules.

    Energy Technology Data Exchange (ETDEWEB)

    Sarobol, Pylin; Hall, Aaron Christopher; Miller, Stephen Samuel; Knight, Marlene E.; LePage, William S.; Sobczak, Catherine Elizabeth.; Wesolowski, Daniel Edward

    2013-09-01

    Molybdenum electrical interconnects for thermoelectric modules were produced by air plasma spraying a 30%CE%BCm size molybdenum powder through a laser-cut Kapton tape mask. Initial feasibility demonstrations showed that the molybdenum coating exhibited excellent feature and spacing retention (~170%CE%BCm), adhered to bismuth-telluride, and exhibited electrical conductivity appropriate for use as a thermoelectric module interconnect. A design of experiments approach was used to optimize air plasma spray process conditions to produce a molybdenum coating with low electrical resistivity. Finally, a molybdenum coating was successfully produced on a fullscale thermoelectric module. After the addition of a final titanium/gold layer deposited on top of the molybdenum coating, the full scale module exhibited an electrical resistivity of 128%CE%A9, approaching the theoretical resistivity value for the 6mm module leg of 112%CE%A9. Importantly, air plasma sprayed molybdenum did not show significant chemical reaction with bismuth-telluride substrate at the coating/substrate interface. The molybdenum coating microstructure consisted of lamellar splats containing columnar grains. Air plasma sprayed molybdenum embedded deeply (several microns) into the bismuth-telluride substrate, leading to good adhesion between the coating and the substrate. Clusters of round pores (and cracks radiating from the pores) were found immediately beneath the molybdenum coating. These pores are believed to result from tellurium vaporization during the spray process where the molten molybdenum droplets (2623%C2%B0C) transferred their heat of solidification to the substrate at the moment of impact. Substrate cooling during the molybdenum deposition process was recommended to mitigate tellurium vaporization in future studies.

  4. Solar-energy conversion by combined photovoltaic converters with CdTe and CuInSe2 base layers

    International Nuclear Information System (INIS)

    Khrypunov, G. S.; Sokol, E. I.; Yakimenko, Yu. I.; Meriuts, A. V.; Ivashuk, A. V.; Shelest, T. N.

    2014-01-01

    The possibility of the combined use of bifacial thin-film solar cells based on CdTe and frontal solar cells with a CuInSe 2 base layer in tandem structures is experimentally confirmed. It is found that, for the use of bifacial solar cells based on cadmium telluride in a tandem structure, the optimal thickness of their base layer should be 1 μm. The gain in the efficiency of the tandem structure, compared with an individual CuInSe 2 -based solar cell, is 1.8% in the case of series-connected solar cells and 1.3%, for parallel-connected

  5. Cadmium telluride gamma-radiation detectors with a high energy resolution

    International Nuclear Information System (INIS)

    Alekseeva, L.A.; Dorogov, P.G.; Ivanov, V.I.; Khusainov, A.K.

    1985-01-01

    This paper considers the possibility of improving the energy resolution of cadmium telluride gamma-radiation detectors through the choice of the geometry and size of the sensitive region of the detector. The optimum ratio of the product of the mobility and lifetime for electrons to the same product for holes from the point of view of energy resolution is greater than or equal to 10 2 for a detector of spherical geometry and should be less than or equal to 10 for a cylindrical geometry and approximately 1 for a planar geometry. The optimum values of the major and minor radii of a spherical detector are calculated

  6. Specific features of the photoconductivity of semi-insulating cadmium telluride

    Energy Technology Data Exchange (ETDEWEB)

    Golubyatnikov, V. A.; Grigor’ev, F. I.; Lysenko, A. P., E-mail: aplysenko@hse.ru; Strogankova, N. I.; Shadov, M. B. [National Research University Higher School of Economics, Moscow Institute of Electronics and Mathematics (Russian Federation); Belov, A. G. [OAO GIREDMET State Research and Design Institute of the Rare-Metal Industry (Russian Federation)

    2014-12-15

    The effect of local illumination providing a high level of free-carrier injection on the conductivity of a sample of semi-insulating cadmium telluride and on the properties of ohmic contacts to the sample is studied. It is found that, irrespective of the illumination region, the contact resistance of ohmic contacts decreases and the concentration of majority carriers in the sample grows in proportion to the illumination intensity. It is shown that inherent heterogeneities in crystals of semi-insulating semiconductors can be studied by scanning with a light probe.

  7. Iron telluride nanorods-based system for the detection of total mercury in blood

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Prathik; Lin, Zong-Hong [Department of Chemistry, National Taiwan University, 1, Section 4, Roosevelt Road, Taipei 106, Taiwan (China); Liang, Chi-Te [Department of Physics, National Taiwan University, 1, Section 4, Roosevelt Road, Taipei 106, Taiwan (China); Chang, Huan-Tsung, E-mail: changht@ntu.edu.tw [Department of Chemistry, National Taiwan University, 1, Section 4, Roosevelt Road, Taipei 106, Taiwan (China)

    2012-12-15

    Graphical abstract: Elucidation of the detection of mercury using iron telluride nanorods (FeTe NRs), and dose-response curve for varying concentrations of Hg{sup 2+}. Highlights: Black-Right-Pointing-Pointer Iron telluride nanorods (FeTe NRs) are prepared from tellurium nanowires (Te NWs). Black-Right-Pointing-Pointer Mercury telluride nanorods (HgTe NRs) form by cation exchange reaction of FeTe NRs. Black-Right-Pointing-Pointer Fe{sup 2+} ions released catalyze the oxidation of ABTS by H{sub 2}O{sub 2}. Black-Right-Pointing-Pointer Mercury is effectively determined in blood with an LOD of 1.31 nM at S/N ratio 3. - Abstract: We have developed a simple, colorimetric iron telluride (FeTe) nanorods (NRs) based system for the detection of mercury, mainly based on the cation exchange reaction between FeTe NRs and Hg{sup 2+}. FeTe NRs (length, 105 {+-} 21 nm) react with Hg{sup 2+} to form HgTe NRs (length, 112 {+-} 26 nm) and consequently release Fe{sup 2+} ions that catalyzes the oxidation between a peroxidase substrate 2,2 Prime -azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid) diammonium salt (ABTS) and H{sub 2}O{sub 2}. The concentration of Fe{sup 2+} and thereby Hg{sup 2+} can be determined by measuring the absorbance of the ABTS oxidized product at 418 nm. This approach allows the detection of Hg{sup 2+}, with a limit of detection of 1.31 nM at a signal-to-noise ratio 3 and a linear range 5-100 nM (R{sup 2} = 0.99). The low-cost, simple, sensitive, and reproducible assay has been validated for the detection of Hg{sup 2+} in a blood sample (SRM 955c), with the result being in good agreement with that provided by National Institute of Standards and Technology.

  8. Crystalline perfection and mechanical investigations on vertical Bridgman grown Bismuth telluride (Bi_2Te_3) single crystals for thermoelectric applications

    International Nuclear Information System (INIS)

    Krishna, Anuj; Vijayan, N.; Singh, Budhendra; Thukral, Kanika; Maurya, K.K.

    2016-01-01

    High efficiency thermoelectric materials plays a vital role in power generation and refrigeration applications. Bismuth telluride (Bi_2Te_3) is one among them. In the present work single crystal of bismuth telluride was grown using vertical Bridgman technique. The phase of grown crystals was analysed using a powder X-ray diffractometer. Quality of the grown crystal was assessed by using high resolution X-ray diffractometer and observed that it is fairly good. Further mechanical investigations on grown crystal was carried out using nano-indentation technique and various mechanical properties like hardness, stiffness and Young’s modulus were evaluated. Observed results clearly indicate its suitability for thermoelectric applications.

  9. Lead telluride with increased mechanical stability for cylindrical thermoelectric generators; Bleitellurid mit erhoehter mechanischer Stabilitaet fuer zylindrische thermoelektrische Generatoren

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, Andreas

    2013-04-30

    The aim of this work is to improve the mechanical stability of lead telluride (PbTe), trying to vary its mechanical properties independently from its thermoelectric properties. Thus the influence of material preparation as well as different dopants on the mechanical and thermoelectric properties of lead telluride is being analysed. When using appropriately set process parameters, milling and sintering of lead telluride increases the material's hardness. With sintering temperatures exceeding 300 C stable material of high relative density can be achieved. Milling lead telluride generates lattice defects leading to a reduction of the material's charge carrier density. These defects can be reduced by increased sintering temperatures. Contamination of the powder due to the milling process leads to bloating during thermal cycling and thus reduced density of the sintered material. In addition to that, evaporation of tellurium at elevated temperatures causes instability of the material's thermoelectric properties. Based on the experimental results obtained in this work, the best thermoelectric and mechanical properties can be obtained by sintering coarse powders at around 400 C. Within this work a concept was developed to vary the mechanical properties of lead telluride via synthesis of PbTe with electrically nondoping elements, which thus may keep the thermoelectric properties unchanged. Therefore, the mechanical and thermoelectric properties of Pb{sub 1-x}Ca{sub x}Te were investigated. Doping pure PbTe with calcium causes a significant increase of the material's hardness while only slightly decreasing the charge carrier density and thus keeping the thermoelectric properties apart from a slight reduction of the electrical conductivity nearly unchanged. The abovementioned concept is proven using sodium doped lead telluride, as it is used for thermoelectric generators: The additional doping with calcium again increases the material's hardness while its thermoelectric

  10. Lead telluride with increased mechanical stability for cylindrical thermoelectric generators; Bleitellurid mit erhoehter mechanischer Stabilitaet fuer zylindrische thermoelektrische Generatoren

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, Andreas

    2013-04-30

    The aim of this work is to improve the mechanical stability of lead telluride (PbTe), trying to vary its mechanical properties independently from its thermoelectric properties. Thus the influence of material preparation as well as different dopants on the mechanical and thermoelectric properties of lead telluride is being analysed. When using appropriately set process parameters, milling and sintering of lead telluride increases the material's hardness. With sintering temperatures exceeding 300 C stable material of high relative density can be achieved. Milling lead telluride generates lattice defects leading to a reduction of the material's charge carrier density. These defects can be reduced by increased sintering temperatures. Contamination of the powder due to the milling process leads to bloating during thermal cycling and thus reduced density of the sintered material. In addition to that, evaporation of tellurium at elevated temperatures causes instability of the material's thermoelectric properties. Based on the experimental results obtained in this work, the best thermoelectric and mechanical properties can be obtained by sintering coarse powders at around 400 C. Within this work a concept was developed to vary the mechanical properties of lead telluride via synthesis of PbTe with electrically nondoping elements, which thus may keep the thermoelectric properties unchanged. Therefore, the mechanical and thermoelectric properties of Pb{sub 1-x}Ca{sub x}Te were investigated. Doping pure PbTe with calcium causes a significant increase of the material's hardness while only slightly decreasing the charge carrier density and thus keeping the thermoelectric properties apart from a slight reduction of the electrical conductivity nearly unchanged. The abovementioned concept is proven using sodium doped lead telluride, as it is used for thermoelectric generators: The additional doping with calcium again increases the material's hardness while

  11. Advanced Processing of CdTe- and CuInxGa1-xSe2-Based Solar Cells: Final Report: 18 April 1995 - 31 May 1998

    International Nuclear Information System (INIS)

    Jayapalan, A.; Tetali, B.; Ferekides, C.S.; Marinskiy, D.; Morel, D.L.; Lin, H.; Sankaranarayanan, H.; Bhatt, R.; Narayanaswamy, R.; Prabhakaran, R.; Marinskaya, S.; Zafar, S.

    1999-01-01

    This report summarizes work performed by the University of South Florida Department of Electrical Engineering under this subcontract. The Cadmium telluride(CdTe) portion of this project deals with the development of high-efficiency thin-filmed CdTe solar cells using fabrication techniques that are suitable for manufacturing environments

  12. Chelators for investigating zinc metalloneurochemistry

    OpenAIRE

    Radford, Robert John; Lippard, Stephen J.

    2013-01-01

    The physiology and pathology of mobile zinc signaling has become an important topic in metalloneurochemistry. To study the action of mobile zinc effectively, specialized tools are required that probe the temporal and positional changes of zinc ions within live tissue and cells. In the present article we describe the design and implementation of selective zinc chelators as antagonists to interrogate the function of mobile zinc, with an emphasis on the pools of vesicular zinc in the terminals o...

  13. Zinc triggers microglial activation.

    Science.gov (United States)

    Kauppinen, Tiina M; Higashi, Youichirou; Suh, Sang Won; Escartin, Carole; Nagasawa, Kazuki; Swanson, Raymond A

    2008-05-28

    Microglia are resident immune cells of the CNS. When stimulated by infection, tissue injury, or other signals, microglia assume an activated, "ameboid" morphology and release matrix metalloproteinases, reactive oxygen species, and other proinflammatory factors. This innate immune response augments host defenses, but it can also contribute to neuronal death. Zinc is released by neurons under several conditions in which microglial activation occurs, and zinc chelators can reduce neuronal death in animal models of cerebral ischemia and neurodegenerative disorders. Here, we show that zinc directly triggers microglial activation. Microglia transfected with a nuclear factor-kappaB (NF-kappaB) reporter gene showed a severalfold increase in NF-kappaB activity in response to 30 microm zinc. Cultured mouse microglia exposed to 15-30 microm zinc increased nitric oxide production, increased F4/80 expression, altered cytokine expression, and assumed the activated morphology. Zinc-induced microglial activation was blocked by inhibiting NADPH oxidase, poly(ADP-ribose) polymerase-1 (PARP-1), or NF-kappaB activation. Zinc injected directly into mouse brain induced microglial activation in wild-type mice, but not in mice genetically lacking PARP-1 or NADPH oxidase activity. Endogenous zinc release, induced by cerebral ischemia-reperfusion, likewise induced a robust microglial reaction, and this reaction was suppressed by the zinc chelator CaEDTA. Together, these results suggest that extracellular zinc triggers microglial activation through the sequential activation of NADPH oxidase, PARP-1, and NF-kappaB. These findings identify a novel trigger for microglial activation and a previously unrecognized mechanism by which zinc may contribute to neurological disorders.

  14. Strain effect on the heat transport properties of bismuth telluride nanofilms with a hole

    Science.gov (United States)

    Fang, Te-Hua; Chang, Win-Jin; Wang, Kuan-Yu; Huang, Chao-Chun

    2018-06-01

    We investigated the mechanical behavior of bismuth telluride nanofilms with holes by using an equilibrium molecular dynamics (MD) approach. The holes had diameters of 20, 30, 40, and 50 Å. The thermal conductivity values of the nanofilms were calculated under different strains at different temperatures using a nonequilibrium MD simulation. The simulation revealed that the thermal conductivity of a bismuth telluride nanofilm with a hole decreases with an increase in hole diameter at different strains. For a film with a perfect structure at 300 K, a 48% reduction (from 0.33 to 0.17 W/m K) in the thermal conductivity was observed at a 7% tensile strain. In addition, the thermal conductivity increased by approximately 39% (from 0.33 to 0.46 W/m K) at a 7% compressive strain. A very low value (0.11 W/m K) of thermal conductivity is obtained for the nanofilm with a hole diameter of 50 Å at a 7% tensile strain at 300 K.

  15. Effect of electronic contribution on temperature-dependent thermal transport of antimony telluride thin film

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won-Yong; Park, No-Won [Department of Physics, Chung-Ang University, Seoul 156-756 (Korea, Republic of); Hong, Ji-Eun [Department of Materials Engineering, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Yoon, Soon-Gil, E-mail: sgyoon@cnu.ac.kr [Department of Materials Engineering, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Koh, Jung-Hyuk [School of Electrical and Electronics Engineering, Chung-Ang University, Seoul 156-756 (Korea, Republic of); Lee, Sang-Kwon, E-mail: sangkwonlee@cau.ac.kr [Department of Physics, Chung-Ang University, Seoul 156-756 (Korea, Republic of)

    2015-01-25

    Highlights: • We investigated thermal transport of the antimony telluride thin films. • The contribution of the electronic thermal conductivity increased up to ∼77% at 300 K. • We theoretically analyze and explain the high contribution of electronic component. - Abstract: We study the theoretical and experimental characteristics of thermal transport of 100 nm and 500 nm-thick antimony telluride (Sb{sub 2}Te{sub 3}) thin films prepared by radio frequency magnetron sputtering. The thermal conductivity was measured at temperatures ranging from 20 to 300 K, using four-point-probe 3-ω method. Out-of-plane thermal conductivity of the Sb{sub 2}Te{sub 3} thin film was much lesser in comparison to the bulk material in the entire temperature range, confirming that the phonon- and electron-boundary scattering are enhanced in thin films. Moreover, we found that the contribution of the electronic thermal conductivity (κ{sub e}) in total thermal conductivity (κ) linearly increased up to ∼77% at 300 K with increasing temperature. We theoretically analyze and explain the high contribution of electronic component of thermal conductivity towards the total thermal conductivity of the film by a modified Callaway model. Further, we find the theoretical model predictions to correspond well with the experimental results.

  16. Possible bicollinear nematic state with monoclinic lattice distortions in iron telluride compounds

    Energy Technology Data Exchange (ETDEWEB)

    Bishop, Christopher B. [Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Herbrych, Jacek W. [Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Dagotto, Elbio R. [Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Moreo, Adriana [Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-07-15

    Here, iron telluride (FeTe) is known to display bicollinear magnetic order at low temperatures together with a monoclinic lattice distortion. Because the bicollinear order can involve two different wave vectors (π/2,π/2) and (π/2,–π/2), symmetry considerations allow for the possible stabilization of a nematic state with short-range bicollinear order coupled to monoclinic lattice distortions at a TS higher than the temperature TN where long-range bicollinear order fully develops. As a concrete example, the three-orbital spin-fermion model for iron telluride is studied with an additional coupling ˜λ12 between the monoclinic lattice strain and an orbital-nematic order parameter with B2g symmetry. Monte Carlo simulations show that with increasing ˜λ12 the first-order transition characteristic of FeTe splits and bicollinear nematicity is stabilized in a (narrow) temperature range. In this new regime, the lattice is monoclinically distorted and short-range spin and orbital order breaks rotational invariance. A discussion of possible realizations of this exotic state is provided.

  17. The use of cadmium telluride γ spectrometers in monitoring activity deposited in nuclear power stations

    International Nuclear Information System (INIS)

    Jones, L.T.

    1977-01-01

    The ability to inspect and test key components and when necessary repair or replace them is a significant factor in the safety case submitted before consent is given for construction of a nuclear reactor. A knowledge of the probable rate of deposition and isotopic composition of radioactive contamination in these areas is necessary and since it is not always practicable to take samples away to the laboratory for analysis, direct gamma ray spectroscopy in the contaminated environment is sometimes used. The experience of direct monitoring with a cadmium telluride spectrometer in two such reactor situations is reported. In the first situation, a remotely cooled intrinsic Germanium spectrometer was used in equivalent positions and spectra from both systems are presented. The relative merits of the two systems are discussed. In the second situation, measurements were made in an environment at 70 deg C in radiation levels of 10Rh -1 . An improvised cooling system was used to maintain the Cadmium Telluride at about 20 deg C and Pile-up Rejection was used to enable count rates of about 10 5 s -1 to be handled. It is noted that the usually quoted detector parameters, resolution and crystal volume, are not necessarily the most important in practical spectrometry of mixed isotopes. As with germanium detectors, the most useful parameter is probably the Peak-to-Compton ratio

  18. Zinc phosphate conversion coatings

    Science.gov (United States)

    Sugama, Toshifumi

    1997-01-01

    Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate .alpha.-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal.

  19. From zinc selenate to zinc selenide nano structures synthesized by reduction process

    International Nuclear Information System (INIS)

    Hutagalung, S.D.; Eng, S.T.; Ahmad, Z.A.; Ishak Mat; Yussof Wahab

    2009-01-01

    One-dimensional nano structure materials are very attractive because of their electronic and optical properties depending on their size. It is well known that properties of material can be tuned by reducing size to nano scale because at the small sizes, that they behave differently with its bulk materials and the band gap will control by the size. The tunability of the band gap makes nano structured materials useful for many applications. As one of the wide band gaps semiconductor compounds, zinc selenide (ZnSe) nano structures (nanoparticles, nano wires, nano rods) have received much attention for the application in optoelectronic devices, such as blue laser diode, light emitting diodes, solar cells and IR optical windows. In this study, ZnSe nano structures have been synthesized by reduction process of zinc selenate using hydrazine hydrate (N 2 H 4 .2H 2 O). The reductive agent of hydrazine hydrate was added to the starting materials of zinc selenate were heat treated at 500 degree Celsius for 1 hour under argon flow to form one-dimensional nano structures. The SEM and TEM images show the formation of nano composite-like structure, which some small nano bar and nano pellets stick to the rod. The x-ray diffraction and elemental composition analysis confirm the formation of mixture zinc oxide and zinc selenide phases. (author)

  20. Zinc fingers, zinc clusters, and zinc twists in DNA-binding protein domains

    International Nuclear Information System (INIS)

    Vallee, B.L.; Auld, D.S.; Coleman, J.E.

    1991-01-01

    The authors recognize three distinct motifs of DNA-binding zinc proteins: (i) zinc fingers, (ii) zinc clusters, and (iii) zinc twists. Until very recently, x-ray crystallographic or NMR three-dimensional structure analyses of DNA-binding zinc proteins have not been available to serve as standards of reference for the zinc binding sites of these families of proteins. Those of the DNA-binding domains of the fungal transcription factor GAL4 and the rat glucocorticoid receptor are the first to have been determined. Both proteins contain two zinc binding sites, and in both, cysteine residues are the sole zinc ligands. In GAL4, two zinc atoms are bound to six cysteine residues which form a zinc cluster akin to that of metallothionein; the distance between the two zinc atoms of GAL4 is ∼3.5 angstrom. In the glucocorticoid receptor, each zinc atom is bound to four cysteine residues; the interatomic zinc-zinc distance is ∼13 angstrom, and in this instance, a zinc twist is represented by a helical DNA recognition site located between the two zinc atoms. Zinc clusters and zinc twists are here recognized as two distinctive motifs in DNA-binding proteins containing multiple zinc atoms. For native zinc fingers, structural data do not exist as yet; consequently, the interatomic distances between zinc atoms are not known. As further structural data become available, the structural and functional significance of these different motifs in their binding to DNA and other proteins participating in the transmission of the genetic message will become apparent

  1. Structural, Mechanical and Thermodynamic Properties under Pressure Effect of Rubidium Telluride: First Principle Calculations

    Directory of Open Access Journals (Sweden)

    Bidai K.

    2017-06-01

    Full Text Available First-principles density functional theory calculations have been performed to investigate the structural, elastic and thermodynamic properties of rubidium telluride in cubic anti-fluorite (anti-CaF2-type structure. The calculated ground-state properties of Rb2Te compound such as equilibrium lattice parameter and bulk moduli are investigated by generalized gradient approximation (GGA-PBE that are based on the optimization of total energy. The elastic constants, Young’s and shear modulus, Poisson ratio, have also been calculated. Our results are in reasonable agreement with the available theoretical and experimental data. The pressure dependence of elastic constant and thermodynamic quantities under high pressure are also calculated and discussed.

  2. Heavily doped GaAs:Te layers grown by MOVPE using diisopropyl telluride as a source

    Energy Technology Data Exchange (ETDEWEB)

    Daniltsev, V. M.; Demidov, E. V.; Drozdov, M. N.; Drozdov, Yu. N., E-mail: drozdyu@ipmras.ru; Kraev, S. A.; Surovegina, E. A.; Shashkin, V. I.; Yunin, P. A. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation)

    2016-11-15

    The capabilities of GaAs epitaxial layers extremely heavily doped with tellurium by metal-organic vapor-phase epitaxy using diisopropyl telluride as a source are studied. It is shown that tellurium incorporation into GaAs occurs to an atomic concentration of 10{sup 21} cm{sup –3} without appreciable diffusion and segregation effects. Good carrier concentrations (2 × 10{sup 19} cm{sup –3}) and specific contact resistances of non-alloyed ohmic contacts (1.7 × 10{sup –6} Ω cm{sup 2}) give grounds to use such layers to create non-alloyed ohmic contacts in electronic devices. A sharp decrease in the electrical activity of Te atoms, a decrease in the electron mobility, and an increase in the contact resistance at atomic concentrations above 2 × 10{sup 20} cm{sup –3} are detected.

  3. Effect of ball milling time on thermoelectric properties of bismuth telluride nanomaterials

    Science.gov (United States)

    Khade, Poonam; Bagwaiya, Toshi; Bhattacharaya, Shovit; Singh, Ajay; Jha, Purushottam; Shelke, Vilas

    2018-04-01

    The effect of different milling time on thermoelectric properties of bismuth telluride (Bi2Te3) was investigated. The nanomaterial was prepared by varying the ball milling time and followed by hot press sintering. The crystal structure and phase formation were verified by X-ray diffraction and Raman Spectroscopy. The experimental results show that electrical conductivity increases whereas thermal conductivity decreases with increasing milling time. The negative sign of seebeck coefficient indicate the n-type nature with majority charge carriers of electrons. A maximum figure of merit about 0.55 is achieved for l5hr ball milled Bi2Te3 sample. The present study demonstrates the simple and cost-effective method for synthesis of Bi2Te3 thermoelectric material at large scale thermoelectric applications.

  4. High pressure and doping effects on the Curie temperature in chromium telluride

    International Nuclear Information System (INIS)

    Grazhdankina, N.P.; Bersenev, Yu.S.

    1976-01-01

    Results of an experimental investigation of the effect of hydrostatic pressure (up to 12 kbars) on the Curie temperature Tsub(c) of solid CrTsub(1-x)Xsub(x) solutions (X=Se, Sb) are presented for x concentration values up to 0.5. The baric coefficients γ=Tsub(c)sup(-1)(dTsub(c)/dP) for all alloys investigated are negative. However the γ(x) dependence is determined by the X alloy component and correspondingly by the nature of the compression which may be either isotropic (X=Se) or anisotropic (X=Sb). Possible mechanisms of exchange spin coupling in the alloys investigated are discussed on the basis of the data obtained. It is concluded that two types of exchange interactions coexist in chromium telluride: indirect exchange of localized electrons via the anion and interaction between collectivized electrons in the narrow 3d band energy determines the Curie temperature

  5. An additive approach to low temperature zero pressure sintering of bismuth antimony telluride thermoelectric materials

    Science.gov (United States)

    Catlin, Glenn C.; Tripathi, Rajesh; Nunes, Geoffrey; Lynch, Philip B.; Jones, Howard D.; Schmitt, Devin C.

    2017-03-01

    This paper presents an additive-based approach to the formulation of thermoelectric materials suitable for screen printing. Such printing processes are a likely route to such thermoelectric applications as micro-generators for wireless sensor networks and medical devices, but require the development of materials that can be sintered at ambient pressure and low temperatures. Using a rapid screening process, we identify the eutectic combination of antimony and tellurium as an additive for bismuth-antimony-telluride that enables good thermoelectric performance without a high pressure step. An optimized composite of 15 weight percent Sb7.5Te92.5 in Bi0.5Sb1.5Te3 is scaled up and formulated into a screen-printable paste. Samples fabricated from this paste achieve a thermoelectric figure of merit (ZT) of 0.74 using a maximum processing temperature of 748 K and a total thermal processing budget of 12 K-hours.

  6. Trace analysis in cadmium telluride by heavy ion induced X-ray emission and by SIMS

    International Nuclear Information System (INIS)

    Scharager, C.; Stuck, R.; Siffert, P.; Cailleret, J.; Heitz, Ch.; Lagarde, G.; Tenorio, D.

    1979-01-01

    The possibilities of using both selective heavy ion induced X-ray emission and secondary ion mass spectroscopy (SIMS), for the identification of impurities present at low concentrations in cadmium telluride are examined. The relative concentrations of the impurities along CdTe crystals have been determined by exciting the X-ray emission of the elements in several slices with Ar and Kr ions and by comparing the relative characteristic X-ray emission yields. As a consequence of the quasimolecular inner shell ionization mechanism in heavy ion-atom collisions, Ar and Kr ions allow a strong excitation of the main impurities seen by SIMS namely Si, Cl and Ge, As, with only a minor contribution of Cd and Te. From the changes of the concentrations of the various impurities along the crystal, informations about segregation coefficients and compensation can be obtained

  7. Angular dependence of magnetization reversal in epitaxial chromium telluride thin films with perpendicular magnetic anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Pramanik, Tanmoy, E-mail: pramanik.tanmoy@utexas.edu; Roy, Anupam, E-mail: anupam@austin.utexas.edu; Dey, Rik, E-mail: rikdey@utexas.edu; Rai, Amritesh; Guchhait, Samaresh; Movva, Hema C.P.; Hsieh, Cheng-Chih; Banerjee, Sanjay K.

    2017-09-01

    Highlights: • Perpendicular magnetic anisotropy in epitaxial Cr{sub 2}Te{sub 3} has been investigated. • Presence of a relatively strong second order anisotropy contribution is observed. • Magnetization reversal is explained quantitatively using a 1D defect model. • Relative roles of nucleation and pinning in magnetization reversal are discussed. • Domain structures and switching process are visualized by micromagnetic simulation. - Abstract: We investigate magnetic anisotropy and magnetization reversal mechanism in chromium telluride thin films grown by molecular beam epitaxy. We report existence of strong perpendicular magnetic anisotropy in these thin films, along with a relatively strong second order anisotropy contribution. The angular variation of the switching field observed from the magnetoresistance measurement is explained quantitatively using a one-dimensional defect model. The model reveals the relative roles of nucleation and pinning in the magnetization reversal, depending on the applied field orientation. Micromagnetic simulations are performed to visualize the domain structure and switching process.

  8. First operation of cesium telluride photocathodes in the TTF injector RF gun

    CERN Document Server

    Sertore, D; Flöttmann, K; Stephan, F; Zapfe, K; Michelato, P

    2000-01-01

    During the run 1998/1999 a new injector based on a laser-driven RF gun was brought in operation at the TESLA Test Facility (TTF) linac at DESY, in order to produce the beam structure and quality required either by TeV collider and SASE FEL experiments. High quantum efficiency cesium telluride photocathodes, prepared at Milano and transferred to DESY, have been successfully operated in the RF gun. A bunch charge of 50 nC, only limited by space charge effects, was achieved. The photocathodes have shown an operative lifetime of several months. A new cathode surface finishing has showed a promising decrease of the photocathode dark current. Measurements of dark current, quantum efficiency and lifetime are reported.

  9. Zinc in diet

    Science.gov (United States)

    ... Effects Symptoms of zinc deficiency include: Frequent infections Hypogonadism in males Loss of hair Poor appetite Problems with the ... any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should ...

  10. Novel aspects of application of cadmium telluride quantum dots nanostructures in radiation oncology

    Energy Technology Data Exchange (ETDEWEB)

    Fazaeli, Yousef; Feizi, Shahzad [Nuclear Science and Technology Research Institute (NSTRI), Radiation Application Research School, Karaj (Iran, Islamic Republic of); Zare, Hakimeh; Karimi, Shokufeh [Yazd University, Department of Physics, Yazd (Iran, Islamic Republic of); Rahighi, Reza [Sharif University of Technology, Department of Physics, Tehran (Iran, Islamic Republic of)

    2017-08-15

    In the last two decades, quantum dots nanomaterials have garnered a great deal of scientific interest because of their unique properties. Quantum dots (QDs) are inorganic fluorescent nanocrystals in the size range between 1 and 20 nm. Due to their structural properties, they possess distinctive properties and behave in different way from crystals in macro scale, in many branches of human life. Cadmium telluride quantum dots (CdTe QDs) were labeled with {sup 68}Ga radio nuclide for fast in vivo targeting and coincidence imaging of tumors. Using instant paper chromatography, the physicochemical properties of the Cadmium telluride quantum dots labeled with {sup 68}Ga NPs ({sup 68}Ga rate at CdTe QDs) were found high enough stable in organic phases, e.g., a human serum, to be reliably used in bioapplications. In vivo biodistribution of the {sup 68}Ga rate at CdTe QDs nanoconposite was investigated in rats bearing fibro sarcoma tumor after various post-injection periods of time. The {sup 68}Ga NPs exhibited a rapid as well as high tumor uptake in a very short period of time (less than 10 min), resulting in an efficient tumor targeting/imaging agent. Meantime, the low lipophilicity of the {sup 68}Ga NPs caused to their fast excretion throughout the body by kidneys (as also confirmed by the urinary tract). Because of the short half-life of {sup 68}Ga radionuclide, the {sup 68}Ga rate at CdTe QDs with an excellent tumor targeting/imaging and fast washing out from the body can be suggested as one of the most effective and promising nanomaterials in nanotechnology-based cancer diagnosis and therapy. (orig.)

  11. Novel aspects of application of cadmium telluride quantum dots nanostructures in radiation oncology

    Science.gov (United States)

    Fazaeli, Yousef; Zare, Hakimeh; Karimi, Shokufeh; Rahighi, Reza; Feizi, Shahzad

    2017-08-01

    In the last two decades, quantum dots nanomaterials have garnered a great deal of scientific interest because of their unique properties. Quantum dots (QDs) are inorganic fluorescent nanocrystals in the size range between 1 and 20 nm. Due to their structural properties, they possess distinctive properties and behave in different way from crystals in macro scale, in many branches of human life. Cadmium telluride quantum dots (CdTe QDs) were labeled with 68Ga radio nuclide for fast in vivo targeting and coincidence imaging of tumors. Using instant paper chromatography, the physicochemical properties of the Cadmium telluride quantum dots labeled with 68Ga NPs (68Ga@ CdTe QDs) were found high enough stable in organic phases, e.g., a human serum, to be reliably used in bioapplications. In vivo biodistribution of the 68Ga@ CdTe QDs nanoconposite was investigated in rats bearing fibro sarcoma tumor after various post-injection periods of time. The 68Ga NPs exhibited a rapid as well as high tumor uptake in a very short period of time (less than 10 min), resulting in an efficient tumor targeting/imaging agent. Meantime, the low lipophilicity of the 68Ga NPs caused to their fast excretion throughout the body by kidneys (as also confirmed by the urinary tract). Because of the short half-life of 68Ga radionuclide, the 68Ga@ CdTe QDs with an excellent tumor targeting/imaging and fast washing out from the body can be suggested as one of the most effective and promising nanomaterials in nanotechnology-based cancer diagnosis and therapy.

  12. Two dimensional self-assembly zinc porphyrin and zinc phthalocyanine heterojunctions with record high power conversion efficiencies

    Science.gov (United States)

    Yu, Junting; Jiang, Zhou; Hao, Yifan; Zhu, Qianhong; Zhao, Mingliang; Jiang, Xue; Zhao, Jijun

    2018-06-01

    Compared to inorganic solar cells, the power conversion efficiencies (PCEs) of organic solar cells are much lower, but they are compensated by many merits such as lower cost, less weight, and tunable structures, making them prospective for further applications. Porphyrin and phthalocyanine are the two most significant materials for organic solar cells due to their strong light-absorbing properties and semiconductor characteristics. However, there is little research on the 2D heterojunction solar cells based on these two materials, meanwhile the PCEs of them are still low. Here we have self-assembled several 2D zinc porphyrins (ZnPors) and performed first-principles simulation to demonstrate their good stability, suitable light harvesting, and high charge carrier mobility. By perfectly matching lattice constants and molecular energy levels between those 2D ZnPors and our previous proposed zinc phthalocyanines (ZnPcs), 11 type-II organic heterojunctions are constructed to further improve their charge separation capability. Those advantages endow 2D ZnPors and ZnPcs appreciable PCEs for solar cells. Among them, the theoretical PCE of 2D ZnPors/ZnPcs heterojunctions achieves as high as 19.84%, which exceeds all reported organic solar cells, and even approaches the PCEs of inorganic solar cells. These results indicate that our 2D ZnPors and 2D ZnPcs are good candidate materials for future organic solar cells.

  13. The bioavailability of four zinc oxide sources and zinc sulphate in broiler chickens

    OpenAIRE

    Veldkamp, T.; Diepen, van, J.T.M.; Bikker, P.

    2014-01-01

    Zinc is an essential trace element for all farm animal species. It is commonly included in animal diets as zinc oxide, zinc sulphate or organically bound zinc. Umicore Zinc Chemicals developed zinc oxide products with different mean particle sizes. Umicore Zinc Chemicals requested Wageningen UR Livestock Research to determine the bioavailability of four zinc oxide sources and zinc sulphate in broiler chickens. A precise estimate of the bioavailability of zinc sources is required both for fulf...

  14. Synthesis of zinc sulfide by chemical vapor deposition using an organometallic precursor: Di-tertiary-butyl-disulfide

    International Nuclear Information System (INIS)

    Vasekar, Parag; Dhakal, Tara; Ganta, Lakshmikanth; Vanhart, Daniel; Desu, Seshu

    2012-01-01

    Zinc sulfide has gained popularity in the last few years as a cadmium-free heterojunction partner for thin film solar cells and is seen as a good replacement for cadmium sulfide due to better blue photon response and non-toxicity. In this work, zinc sulfide films are prepared using an organic sulfur source. We report a simple and repeatable process for development of zinc sulfide using a cost-effective and less hazardous organic sulfur source. The development of zinc sulfide has been studied on zinc oxide-coated glass where the zinc oxide is converted into zinc sulfide. Zinc oxide grown by atomic layer deposition as well as commercially available zinc oxide-coated glass was used. The zinc sulfide synthesis has been studied and the films are characterized using scanning electron microscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and a UV–VIS spectrophotometer. XRD, XPS and optical characterization confirm the zinc sulfide phase formation. - Highlights: ► Synthesis of ZnS using a less-hazardous precursor, di-tertiary-butyl-disulfide. ► ZnS process optimized for two types of ZnO films. ► Preliminary results for a solar cell show an efficiency of 1.09%.

  15. Morphological evolution of the poly(3-hexylthiophene)/[6,6]-phenyl-C61-butyric acid methyl ester, oxidation of the silver electrode, and their influences on the performance of inverted polymer solar cells with a sol-gel derived zinc oxide electron selective layer

    International Nuclear Information System (INIS)

    Liu, Meng-Yueh; Chang, Chin-Hsiang; Chang, Chih-Hua; Tsai, Kao-Hua; Huang, Jing-Shun; Chou, Chen-Yu; Wang, Ing-Jye; Wang, Po-Sheng; Lee, Chun-Yu; Chao, Cha-Hsin; Yeh, Chin-Liang; Wu, Chih-I; Lin, Ching-Fuh

    2010-01-01

    The inverted polymer solar cell (PSC) based on a sol-gel derived zinc oxide (ZnO) thin film as an electron selective layer is investigated. The device performance is improved after the fabricated device is placed in air for a few days. The improvement is attributed to the self-organization of the poly(3-hexylthiophene)/[6,6]-phenyl-C 61 -butyric acid methyl ester layer and oxidation of the silver electrode with time, resulting in a significant enhancement in the short circuit current, fill factor and open circuit voltage. The investigation shows that the inverted PSC based on ZnO thin film exhibits a high efficiency of 3.8% on the 6th day after fabrication without the use of poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) and encapsulation.

  16. Processing of semiconductors and thin film solar cells using electroplating

    Science.gov (United States)

    Madugu, Mohammad Lamido

    The global need for a clean, sustainable and affordable source of energy has triggered extensive research especially in renewable energy sources. In this sector, photovoltaic has been identified as a cheapest, clean and reliable source of energy. It would be of interest to obtain photovoltaic material in thin film form by using simple and inexpensive semiconductor growth technique such as electroplating. Using this growth technique, four semiconductor materials were electroplated on glass/fluorine-doped tin oxide (FTO) substrate from aqueous electrolytes. These semiconductors are indium selenide (In[x]Sey), zinc sulphide (ZnS), cadmium sulphide (CdS) and cadmium telluride (CdTe). In[x]Se[y] and ZnS were incorporated as buffer layers while CdS and CdTe layers were utilised as window and absorber layers respectively. All materials were grown using two-electrode (2E) system except for CdTe which was grown using 3E and 2E systems for comparison. To fully optimise the growth conditions, the as-deposited and annealed layers from all the materials were characterised for their structural, morphological, optical, electrical and defects structures using X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), optical absorption (UV-Vis spectroscopy), photoelectrochemical (PEC) cell measurements, current-voltage (I-V), capacitance-voltage (C-V), DC electrical measurements, ultraviolet photoelectron spectroscopy (UPS) and photoluminescence (PL) techniques. Results show that InxSey and ZnS layers were amorphous in nature and exhibit both n-type and p-type in electrical conduction. CdS layers are n-type in electrical conduction and show hexagonal and cubic phases in both the as-deposited and after annealing process. CdTe layers show cubic phase structure with both n-type and p-type in electrical conduction. CdTe-based solar cell structures with a n-n heterojunction plus large Schottky barrier, as well as multi-layer graded

  17. Structure impact on the thermal and electronic properties of bismuth telluride by ab-initio and molecular dynamics calculations

    International Nuclear Information System (INIS)

    Termentzidis, K; Pokropivny, A; Xiong, S-Y; Chumakov, Y; Volz, S; Woda, M; Cortona, P

    2012-01-01

    We use molecular dynamics and ab-initio methods to predict the thermal and electronic properties of new materials with high figures of merit. The simulated systems are bulk bismuth tellurides with antisite and vacancy defects. Optimizations of the materials under investigation are performed by the SIESTA code for subsequent calculations of force constants, electronic properties, and Seebeck coefficients. The prediction of the thermal conductivity is made by Non-Equilibrium Molecular Dynamics (NEMD) using the LAMMPS code. The thermal conductivity of bulk bismuth telluride with different stoichiometry and with a number of substitution defects is calculated. We have found that the thermal conductivity can be decreased by 60% by introducing vacancy defects. The calculated thermal conductivities for the different structures are compared with the available experimental and theoretical results.

  18. Relationship between maternal serum zinc, cord blood zinc and ...

    African Journals Online (AJOL)

    Background: Adequate in utero supply of zinc is essential for optimal fetal growth because of the role of zinc in cellular division, growth and differentiation. Low maternal serum zinc has been reported to be associated with low birth weight and the later is associated with increased morbidity and mortality in newborns.

  19. The study and microstructure analysis of zinc and zinc oxide

    Czech Academy of Sciences Publication Activity Database

    Luptáková, Natália; Pešlová, F.; Kliber, J.

    2015-01-01

    Roč. 54, č. 1 (2015), s. 43-46 ISSN 0543-5846 Grant - others:KEGA(SK) KEGA 007 TnUAD-4/2013 Institutional support: RVO:68081723 Keywords : zinc * production of zinc oxide * microstructure * chemical composition * zinc slag Subject RIV: JG - Metal lurgy Impact factor: 0.959, year: 2014

  20. Effects of chemical intermixing on electrical and thermal contact conductances at metallized bismuth and antimony telluride interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Devender,; Mehta, Rutvik J.; Ramanath, Ganpati, E-mail: Ramanath@rpi.edu [Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Lofgreen, Kelly; Mahajan, Ravi [Intel Corporation, Assembly Test and Technology Development, Chandler, Arizona 85226 (United States); Yamaguchi, Masashi [Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Borca-Tasciuc, Theodorian [Department of Mechanical Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

    2015-03-15

    Tailoring electrical and thermal contact conductivities (Σ{sub c} and Γ{sub c}) across metallized pnictogen chalcogenide interfaces is key for realizing efficient thermoelectric devices. The authors report that Cu, Ni, Ti, and Ta diffusion and interfacial telluride formation with n-Bi{sub 2}Te{sub 3} and p-Sb{sub 2}Te{sub 3} influence both Σ{sub c} and Γ{sub c}. Cu metallization yields the highest Γ{sub c} and the lowest Σ{sub c}, correlating with maximal metal diffusion and copper telluride formation. Ni diffuses less and yields the highest Σ{sub c} with Sb{sub 2}Te{sub 3} due to p-type nickel telluride formation, which diminishes Σ{sub c} improvement with n-Bi{sub 2}Te{sub 3} interfaces. Ta and Ti contacts yield the lowest properties similar to that in Ni-metallized structures. These correlations between interfacial diffusion and phase formation on electronic and thermal transport properties will be important for devising suitable metallization for thermoelectric devices.

  1. Diffusion of iron in β-iron telluride (Fe1.12Te) by Moessbauer spectroscopy and tracer method

    International Nuclear Information System (INIS)

    Magara, Masaaki; Tsuji, Toshihide; Naito, Keiji

    1993-01-01

    The diffusion coefficient of iron in a β-iron telluride (Fe 1.12 Te) polycrystalline sample was measured by Moessbauer diffusional line broadening method which relates to the collapse of coherence in gamma-ray photon by the atomic jump at local sites. The diffusion coefficient of iron along the c-axis in nearly single crystal of β-iron telluride was also measured by tracer technique which shows the results of an atom transport in long distance. The activation energies for the diffusion of iron in Fe 1.12 Te obtained by the Moessbauer spectroscopy and the tracer method were 91.5±5.4 and 106±23 kJ/mol, respectively. The diffusion coefficients of iron in β-iron telluride obtained by Moessbauer line broadening are in fair agreement with the values averaged from that along c-axis obtained by tracer method and that along a- and b-axes obtained from reaction rate constant between iron and tellurium by the previous study of the present authors. (orig.)

  2. Zinc biofortification of cereals

    DEFF Research Database (Denmark)

    Palmgren, Michael; Clemens, Stephan; Williams, Lorraine E.

    2008-01-01

    The goal of biofortification is to develop plants that have an increased content of bioavailable nutrients in their edible parts. Cereals serve as the main staple food for a large proportion of the world population but have the shortcoming, from a nutrition perspective, of being low in zinc...... and other essential nutrients. Major bottlenecks in plant biofortification appear to be the root-shoot barrier and - in cereals - the process of grain filling. New findings demonstrate that the root-shoot distribution of zinc is controlled mainly by heavy metal transporting P1B-ATPases and the metal...... tolerance protein (MTP) family. A greater understanding of zinc transport is important to improve crop quality and also to help alleviate accumulation of any toxic metals....

  3. Enhanced thermoelectric properties of bismuth telluride-organic hybrid films via graphene doping

    International Nuclear Information System (INIS)

    Rahman, Airul Azha Abd; Umar, Akrajas Ali; Salleh, Muhamad Mat; Chen, Xiaomei; Oyama, Munetaka

    2016-01-01

    The thermoelectric properties of graphene-doped bismuth telluride-PEDOT:PSS-glycerol (hybrid) films were investigated. Prior to the study, p-type and n-type hybrid films were prepared by doping the PEDOT:PSS-glycerol with the p- and n-type bismuth telluride. Graphene-doped hybrid films were prepared by adding graphene particles of concentration ranging from 0.02 to 0.1 wt% into the hybrid films. Films of graphene-doped hybrid system were then prepared on a glass substrate using a spin-coating technique. It was found that the electrical conductivity of the hybrid films increases with the increasing of the graphene-dopant concentration and optimum at 0.08 wt% for both p- and n-type films, namely 400 and 195 S/cm, respectively. Further increasing in the concentration caused a decreasing in the electrical conductivity. Analysis of the thermoelectric properties of the films obtained that the p-type film exhibited significant improvement in its thermoelectric properties, where the thermoelectric properties increased with the increasing of the doping concentration. Meanwhile, for the case of n-type film, graphene doping showed a negative effect to the thermoelectrical properties, where the thermoelectric properties decreased with the increasing of doping concentration. Seebeck coefficient (and power factor) for optimum p-type and n-type hybrid thin films, i.e., doped with 0.08 wt% of graphene, is 20 μV/K (and 160 μW m -1 K -2 ) and 10 μV/K (and 19.5 μW m -1 K -2 ), respectively. The obtained electrical conductivity and thermoelectric properties of graphene-doped hybrid film are interestingly several orders higher than the pristine hybrid films. A thermocouple device fabricated utilizing the p- and n-type graphene-doped hybrid films can generate an electric voltage as high as 2.2 mV under a temperature difference between the hot-side and the cold-side terminal as only low as 55 K. This is equivalent to the output power as high as 24.2 nW (for output load as high as 50

  4. Photovoltaic cells employing zinc phosphide

    Science.gov (United States)

    Barnett, Allen M.; Catalano, Anthony W.; Dalal, Vikram L.; Masi, James V.; Meakin, John D.; Hall, Robert B.

    1984-01-01

    A photovoltaic cell having a zinc phosphide absorber. The zinc phosphide can be a single or multiple crystal slice or a thin polycrystalline film. The cell can be a Schottky barrier, heterojunction or homojunction device. Methods for synthesizing and crystallizing zinc phosphide are disclosed as well as a method for forming thin films.

  5. Environmental risk limits for zinc

    NARCIS (Netherlands)

    Bodar CWM; SEC

    2007-01-01

    Environmental Riks Limits (ERLs) were derived for zinc. ERLs serve as advisory values to set environmental quality standards in the Netherlands. The ERLs for zinc closely follow the outcomes of earlier discussions on zinc within the Water Framework Directive and EC Regulation 793/93. The ERLs

  6. Environmental risk limits for zinc

    NARCIS (Netherlands)

    Bodar CWM; SEC

    2007-01-01

    Environmental Riks Limits (ERLs) were derived for zinc. ERLs serve as advisory values to set environmental quality standards in the Netherlands. The ERLs for zinc closely follow the outcomes of earlier discussions on zinc within the Water Framework Directive and EC Regulation 793/93. The ERLs refer

  7. The bioavailability of four zinc oxide sources and zinc sulphate in broiler chickens

    NARCIS (Netherlands)

    Veldkamp, T.; Diepen, van J.T.M.; Bikker, P.

    2014-01-01

    Zinc is an essential trace element for all farm animal species. It is commonly included in animal diets as zinc oxide, zinc sulphate or organically bound zinc. Umicore Zinc Chemicals developed zinc oxide products with different mean particle sizes. Umicore Zinc Chemicals requested Wageningen UR

  8. Zinc in multiple sclerosis

    DEFF Research Database (Denmark)

    Bredholt, Mikkel; Fredriksen, Jette Lautrup

    2016-01-01

    In the last 35 years, zinc (Zn) has been examined for its potential role in the disease multiple sclerosis (MS). This review gives an overview of the possible role of Zn in the pathogenesis of MS as well as a meta-analysis of studies having measured Zn in serum or plasma in patients with MS...

  9. Influence of germanium nano-inclusions on the thermoelectric power factor of bulk bismuth telluride alloy

    International Nuclear Information System (INIS)

    Satyala, Nikhil; Zamanipour, Zahra; Norouzzadeh, Payam; Krasinski, Jerzy S.; Vashaee, Daryoosh; Tahmasbi Rad, Armin; Tayebi, Lobat

    2014-01-01

    Nanocomposite thermoelectric compound of bismuth telluride (Bi 2 Te 3 ) with 5 at. % germanium nano-inclusions was prepared via mechanically alloying and sintering techniques. The influence of Ge nano-inclusions and long duration annealing on the thermoelectric properties of nanostructured Bi 2 Te 3 were investigated. It was found that annealing has significant effect on the carrier concentration, Seebeck coefficient, and the power factor of the thermoelectric compound. The systematic heat treatment also reduced the density of donor type defects thereby decreasing the electron concentration. While the as-pressed nanocomposite materials showed n-type properties, it was observed that with the increase of annealing time, the nanocomposite gradually transformed to an abundantly hole-dominated (p-type) sample. The long duration annealing (∼500 h) resulted in a significantly enhanced electrical conductivity pertaining to the augmentation in the density and the structural properties of the sample. Therefore, a simultaneous enhancement in both electrical and Seebeck coefficient characteristics resulted in a remarkable increase in the thermoelectric power factor.

  10. N-hydroxysuccinimide-mediated photoelectrooxidation of aliphatic alcohols based on cadmium telluride nanoparticles decorated graphene nanosheets

    International Nuclear Information System (INIS)

    Navaee, Aso; Salimi, Abdollah

    2013-01-01

    A simple nonenzymatic electrochemical protocol is proposed for the oxidation of aliphatic alcohols using formed N-hydroxysuccinimide (NHS) radical cation on the graphene nanosheets/L-cysteine/cadmium telluride quantum dot (QD) nanocomposite (GNs/Cys/CdTe) modified glassy carbon (GC) electrode. At first, graphene oxide (GO) is chemically synthesized from graphite after which Cys is covalently functionalized to GO through formation of amide bonds between carboxylic acid groups of GO and amine groups of Cys. The resulting GNs/Cys is used as a capping agent to synthesize CdTe QD nanoparticles. After the characterization of the as-made nanocomposite which confirmed the successful attachment of CdTe nanoparticles to the GNs, the ability of the GNs/Cys/CdTe modified GC electrode toward the nonenzymatic ethanol electrooxidation is examined in the presence of NHS as an effective mediating system. Our results revealed that the proposed system possess a good activity to NHS electrooxidation and subsequently, ethanol oxidation. Moreover, the GNs/Cys/CdTe modified electrode displayed a significant photoelectrocatalytic activity toward the ethanol oxidation upon illumination by visible light. The photoactive GNs/Cys/CdTe nanohybrid presented here showing favorable photoelectrochemical features for nonenzymatic aliphatic alcohols oxidation may hold great promise to the development of electrochemical sensors and biofuel cells

  11. Heart imaging by cadmium telluride gamma camera European Program 'BIOMED' consortium

    CERN Document Server

    Scheiber, C; Chambron, J; Prat, V; Kazandjan, A; Jahnke, A; Matz, R; Thomas, S; Warren, S; Hage-Hali, M; Regal, R; Siffert, P; Karman, M

    1999-01-01

    Cadmium telluride semiconductor detectors (CdTe) operating at room temperature are attractive for medical imaging because of their good energy resolution providing excellent spatial and contrast resolution. The compactness of the detection system allows the building of small light camera heads which can be used for bedside imaging. A mobile pixellated gamma camera based on 2304 CdTe (pixel size: 3x3 mm, field of view: 15 cmx15 cm) has been designed for cardiac imaging. A dedicated 16-channel integrated circuit has also been designed. The acquisition hardware is fully programmable (DSP card, personal computer-based system). Analytical calculations have shown that a commercial parallel hole collimator will fit the efficiency/resolution requirements for cardiac applications. Monte-Carlo simulations predict that the Moire effect can be reduced by a 15 deg. tilt of the collimator with respect to the detector grid. A 16x16 CdTe module has been built for the preliminary physical tests. The energy resolution was 6.16...

  12. Measurement and Modeling of Blocking Contacts for Cadmium Telluride Gamma Ray Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Beck, Patrick R. [California Polytechnic State Univ. (CalPoly), San Luis Obispo, CA (United States)

    2010-01-07

    Gamma ray detectors are important in national security applications, medicine, and astronomy. Semiconductor materials with high density and atomic number, such as Cadmium Telluride (CdTe), offer a small device footprint, but their performance is limited by noise at room temperature; however, improved device design can decrease detector noise by reducing leakage current. This thesis characterizes and models two unique Schottky devices: one with an argon ion sputter etch before Schottky contact deposition and one without. Analysis of current versus voltage characteristics shows that thermionic emission alone does not describe these devices. This analysis points to reverse bias generation current or leakage through an inhomogeneous barrier. Modeling the devices in reverse bias with thermionic field emission and a leaky Schottky barrier yields good agreement with measurements. Also numerical modeling with a finite-element physics-based simulator suggests that reverse bias current is a combination of thermionic emission and generation. This thesis proposes further experiments to determine the correct model for reverse bias conduction. Understanding conduction mechanisms in these devices will help develop more reproducible contacts, reduce leakage current, and ultimately improve detector performance.

  13. Cadmium telluride nanoparticles loaded on activated carbon as adsorbent for removal of sunset yellow

    Science.gov (United States)

    Ghaedi, M.; Hekmati Jah, A.; Khodadoust, S.; Sahraei, R.; Daneshfar, A.; Mihandoost, A.; Purkait, M. K.

    2012-05-01

    Adsorption is a promising technique for decolorization of effluents of textile dyeing industries but its application is limited due to requirement of high amounts of adsorbent required. The objective of this study was to assess the potential of cadmium telluride nanoparticles loaded onto activated carbon (CdTN-AC) for the removal of sunset yellow (SY) dye from aqueous solution. Adsorption studies were conducted in a batch mode varying solution pH, contact time, initial dye concentration, CdTN-AC dose, and temperature. In order to investigate the efficiency of SY adsorption on CdTN-AC, pseudo-first-order, pseudo-second-order, Elovich, and intra-particle diffusion kinetic models were studied. It was observed that the pseudo-second-order kinetic model fits better than other kinetic models with good correlation coefficient. Equilibrium data were fitted to the Langmuir model. Thermodynamic parameters such as enthalpy, entropy, activation energy, and sticking probability were also calculated. It was found that the sorption of SY onto CdTN-AC was spontaneous and endothermic in nature. The proposed adsorbent is applicable for SY removal from waste of real effluents including pea-shooter, orange drink and jelly banana with efficiency more than 97%.

  14. Fluorescence Stability of Mercaptopropionic Acid Capped Cadmium Telluride Quantum Dots in Various Biochemical Buffers.

    Science.gov (United States)

    Borse, Vivek; Kashikar, Adisha; Srivastava, Rohit

    2018-04-01

    Quantum dots are the semiconductor nanocrystals having unique optical and electronic properties. Quantum dots are category of fluorescent labels utilized for biological tagging, biosensing, bioassays, bioimaging and in vivo imaging as they exhibit very small size, signal brightness, photostability, tuning of light emission range, longer photoluminescence decay time as compared to organic dyes. In this work, we have synthesized and characterized mercaptopropionic acid capped cadmium telluride quantum dots (MPA-CdTe QDs) using hydrothermal method. The study further reports fluorescence intensity stability of quantum dots suspended in different buffers of varying concentration (1-100 mM), stored at various photophysical conditions. Fluorescence intensity values were reduced with increase in buffer concentration. When the samples were stored at room temperature in ambient light condition the quantum dots suspended in different buffers lost the fluorescence intensity after day 15 (except TRIS II). Fluorescence intensity values were found stable for more than 30 days when the samples were stored in dark condition. Samples stored in refrigerator displayed modest fluorescence intensity even after 300 days of storage. Thus, storage of MPA-CdTe QDs in refrigerator may be the suitable choice to maintain its fluorescence stability for longer time for further application.

  15. Effect of reducing agent strength on the growth and thermoelectric performance of nanocrystalline bismuth telluride

    Science.gov (United States)

    Nour, Asmaa; Hassan, Nazly; Refaat, Heba M.; Soliman, Hesham M. A.; El-Dissouky, A.

    2018-03-01

    A novel combination of Trizma, as an environmentally friendly chelating agent, with either weak or strong reducing agent was used to produce n-type bismuth telluride (Bi2Te3) nanocrystals via water-based chemical route. The synthesized powders were consolidated into pellets utilizing spark plasma sintering (SPS). The sintered n-type pellets exhibited potentially high electrical conductivities (5.29 × 105 and 5.23 × 105 S.m‑1) and low lattice thermal conductivities (0.12 and 0.25 Wm‑1K‑1) respectively. These thermoelectric (TE) properties suggested that the partially coherent boundaries permitted significant phonons scattering and electrons transfer. These led to an enhanced figure-of-merit (ZT) values (0.52 and 0.97), which are considered to be significant among the reported ZT values at room-temperature for the undoped synthesized n-type Bi2Te3 nanoparticles. Therefore, the current investigation displayed an efficient method to improve ZT of TE materials via nanostructure orchestrating, resulting in a worthy candidate n-type nanostructured Bi2Te3 for room-temperature TE applications.

  16. Effect of the interface on the mechanical properties and thermal conductivity of bismuth telluride films

    Science.gov (United States)

    Lai, Tang-Yu; Wang, Kuan-Yu; Fang, Te-Hua; Huang, Chao-Chun

    2018-02-01

    Bismuth telluride (Bi2Te3) is a type of thermoelectric material used for energy generation that does not cause pollution. Increasing the thermoelectric conversion efficiency (ZT) is one of the most important steps in the development of thermoelectric components. In this study, we use molecular dynamics to investigate the mechanical properties and thermal conductivity of quintuple layers of Bi2Te3 nanofilms with different atomic arrangements at the interface and study the effects of varying layers, angles, and grain boundaries. The results indicate that the Bi2Te3 nanofilm perfect substrate has the ideal Young’s modulus and thermal conductivity, and the maximum yield stress is observed for a thickness of ∼90 Å. As the interface changed, the structural disorder of atomic arrangement affected the mechanical properties; moreover, the phonons encounter lattice disordered atomic region will produce scattering reduce heat conduction. The results of this investigation are helpful for the application of Bi2Te3 nanofilms as thermoelectric materials.

  17. Investigation of the electrochemical deposition of thick layers of cadmium telluride

    International Nuclear Information System (INIS)

    Rousset, J.

    2007-04-01

    This research thesis deals with the problem of electrochemical deposition of thick layers of cadmium telluride (CdTe) meeting the requirements of high energy radiation detection. The author first recalls the physicochemical properties of CdTe and the basic principles of radiology. He details the different criteria which define a material for X ray detection. He describes the experimental conditions, the nature and preparation of substrates, and the different electrochemical systems used in this research. He studies the impact of the applied potential on the material properties, and compares previously obtained results available in the literature with those obtained in the chosen pool conditions. He discusses the synthesis of CdTe thick layers for which different methods are tested: static in potential, static in intensity, pulsed. The coatings obtained with a given potential and then with a given current are investigated. Finally, the influence of a thermal treatment in presence or absence of a sintering agent on the morphology, the chemical composition, and the crystalline and electric properties of the deposited material is discussed, and the results of the behaviour under X rays of a electrodeposited layer are presented

  18. Zinc bioavailability in the chick

    International Nuclear Information System (INIS)

    Hempe, J.M.

    1987-01-01

    Methods for assessing zinc bioavailability were evaluated in the chick. A low-zinc chick diet was developed using rehydrated, spray-dried egg white autoclaved at 121 C for 30 min as the primary protein source. The relative bioavailability of zinc from soy flour and beef was determined by whole-body retention of extrinsic 65 Zn, and in slope ratio assays for growth rate and tissue zinc. Compared to zinc carbonate added to an egg white-based diet, all methods gave similar estimates of approximately 100% zinc bioavailability for beef but estimates for soy flour varied widely. The slope ratio assay for growth rate gave the best estimate of zinc bioavailability for soy flour. True absorption, as measured by percent isotope retention from extrinsically labeled soy flour, was 47%

  19. The performance of a combined solar photovoltaic (PV) and thermoelectric generator (TEG) system

    DEFF Research Database (Denmark)

    Bjørk, Rasmus; Nielsen, Kaspar Kirstein

    2015-01-01

    The performance of a combined solar photovoltaic (PV) and thermoelectric generator (TEG) system is examined using an analytical model for four different types of commercial PVs and a commercial bismuth telluride TEG. The TEG is applied directly on the back of the PV, so that the two devices have...... the same temperature. The PVs considered are crystalline Si (c-Si), amorphous Si (a-Si), copper indium gallium (di) selenide (CIGS) and cadmium telluride (CdTe) cells. The degradation of PV performance with temperature is shown to dominate the increase in power produced by the TEG, due to the low...... efficiency of the TEG. For c-Si, CIGS and CdTe PV cells the combined system produces a lower power and has a lower efficiency than the PV alone, whereas for an a-Si cell the total system performance may be slightly increased by the TEG....

  20. Interaction Between Yeasts and Zinc

    Science.gov (United States)

    Nicola, Raffaele De; Walker, Graeme

    Zinc is an essential trace element in biological systems. For example, it acts as a cellular membrane stabiliser, plays a critical role in gene expression and genome modification and activates nearly 300 enzymes, including alcohol dehydrogenase. The present chapter will be focused on the influence of zinc on cell physiology of industrial yeast strains of Saccharomyces cerevisiae, with special regard to the uptake and subsequent utilisation of this metal. Zinc uptake by yeast is metabolism-dependent, with most of the available zinc translocated very quickly into the vacuole. At cell division, zinc is distributed from mother to daughter cells and this effectively lowers the individual cellular zinc concentration, which may become zinc depleted at the onset of the fermentation. Zinc influences yeast fermentative performance and examples will be provided relating to brewing and wine fermentations. Industrial yeasts are subjected to several stresses that may impair fermentation performance. Such stresses may also impact on yeast cell zinc homeostasis. This chapter will discuss the practical implications for the correct management of zinc bioavailability for yeast-based biotechnologies aimed at improving yeast growth, viability, fermentation performance and resistance to environmental stresses

  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

    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

  2. Material and Energy Flows Associated with Select Metals in GREET 2. Molybdenum, Platinum, Zinc, Nickel, Silicon

    Energy Technology Data Exchange (ETDEWEB)

    Benavides, Pahola T. [Argonne National Lab. (ANL), Argonne, IL (United States); Dai, Qiang [Argonne National Lab. (ANL), Argonne, IL (United States); Sullivan, John L. [Argonne National Lab. (ANL), Argonne, IL (United States); Kelly, Jarod C. [Argonne National Lab. (ANL), Argonne, IL (United States); Dunn, Jennifer B. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-09-01

    In this work, we analyzed the material and energy consumption from mining to production of molybdenum, platinum, zinc, and nickel. We also analyzed the production of solar- and semiconductor-grade silicon. We described new additions to and expansions of the data in GREET 2. In some cases, we used operating permits and sustainability reports to estimate the material and energy flows for molybdenum, platinum, and nickel, while for zinc and silicon we relied on information provided in the literature.

  3. Does the oral zinc tolerance test measure zinc absorption

    Energy Technology Data Exchange (ETDEWEB)

    Valberg, L.S.; Flanagan, P.R.; Brennan, J.; Chamberlain, M.J.

    1985-01-01

    Increases in plasma zinc concentration were compared with radiozinc absorption after oral test doses. Ten healthy, fasting subjects were each given 385 mumol zinc chloride (25 mg Zn) labelled with 0.5 muCi /sup 65/ZnCl/sub 2/ and a non-absorbed marker, /sup 51/CrCl/sub 3/, dissolved in 100 ml of water; another 10 persons were given 354 mumol zinc chloride and 125 g of minced turkey containing 31 mumol zinc also labelled with /sup 65/Zn and /sup 51/Cr. Measurements were made of plasma zinc concentration at hourly intervals for 5 hours, radiozinc absorption by stool counting of unabsorbed radioactivity 12-36 hours later, and radiozinc retention by whole body counting at 7 days. The mean percentage of radiozinc absorbed and retained in the body from the two test meals was found to be identical (42%). In contrast the increased area under the plasma zinc curve up to 5 hours after the turkey meal, 28 +/- 9 mumol/L (mean +/- SD) was significantly less than that for zinc chloride alone, 47 +/- 15 mumol/L, p less than 0.005. Despite this difference, a good correlation was found between the area under the plasma zinc curve and /sup 65/Zn absorption in individual subjects after each meal. The discrepancy between the results of zinc absorption derived from the plasma zinc curve and /sup 65/Zn absorption for the liquid and solid test meals was most likely explained by binding of zinc to food and delayed gastric emptying of the solid meal. With a test meal of turkey meat at least this dampened the plasma appearance of zinc but did not affect its overall absorption.

  4. Does the oral zinc tolerance test measure zinc absorption

    International Nuclear Information System (INIS)

    Valberg, L.S.; Flanagan, P.R.; Brennan, J.; Chamberlain, M.J.

    1985-01-01

    Increases in plasma zinc concentration were compared with radiozinc absorption after oral test doses. Ten healthy, fasting subjects were each given 385 mumol zinc chloride (25 mg Zn) labelled with 0.5 muCi 65 ZnCl 2 and a non-absorbed marker, 51 CrCl 3 , dissolved in 100 ml of water; another 10 persons were given 354 mumol zinc chloride and 125 g of minced turkey containing 31 mumol zinc also labelled with 65 Zn and 51 Cr. Measurements were made of plasma zinc concentration at hourly intervals for 5 hours, radiozinc absorption by stool counting of unabsorbed radioactivity 12-36 hours later, and radiozinc retention by whole body counting at 7 days. The mean percentage of radiozinc absorbed and retained in the body from the two test meals was found to be identical (42%). In contrast the increased area under the plasma zinc curve up to 5 hours after the turkey meal, 28 +/- 9 mumol/L (mean +/- SD) was significantly less than that for zinc chloride alone, 47 +/- 15 mumol/L, p less than 0.005. Despite this difference, a good correlation was found between the area under the plasma zinc curve and 65 Zn absorption in individual subjects after each meal. The discrepancy between the results of zinc absorption derived from the plasma zinc curve and 65 Zn absorption for the liquid and solid test meals was most likely explained by binding of zinc to food and delayed gastric emptying of the solid meal. With a test meal of turkey meat at least this dampened the plasma appearance of zinc but did not affect its overall absorption

  5. Solar Indices - Solar Flares

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  6. Solar Indices - Solar Ultraviolet

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  7. Solar Indices - Solar Corona

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  8. Solar Indices - Solar Irradiance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  9. Solar thermal energy conversion to electrical power

    International Nuclear Information System (INIS)

    Trinh, Anh-Khoi; González, Ivan; Fournier, Luc; Pelletier, Rémi; Sandoval V, Juan C.; Lesage, Frédéric J.

    2014-01-01

    The conversion of solar energy to electricity currently relies primarily on the photovoltaic effect in which photon bombardment of photovoltaic cells drives an electromotive force within the material. Alternatively, recent studies have investigated the potential of converting solar radiation to electricity by way of the Seebeck effect in which charge carrier mobility is generated by an asymmetric thermal differential. The present study builds upon these latest advancements in the state-of-the-art of thermoelectric system management by combining solar evacuated tube technology with commercially available Bismuth Telluride semiconductor modules. The target heat source is solar radiation and the target heat sink is thermal convection into the ambient air relying on wind aided forced convection. These sources of energy are reproduced in a laboratory controlled environment in order to maintain a thermal dipole across a thermoelectric module. The apparatus is then tested in a natural environment. The novelty of the present work lies in a net thermoelectric power gain for ambient environment applications and an experimental validation of theoretical electrical characteristics relative to a varying electrical load. - Highlights: • Solar radiation maintains a thermal tension which drives an electromotive force. • Voltage, current and electric power are reported and discussed. • Theoretical optimal thermoelectric conversion predictions are presented. • Theory is validated with experimentally measured data

  10. Processing and characterization of new oxy-sulfo-telluride glasses in the Ge-Sb-Te-S-O system

    International Nuclear Information System (INIS)

    Smith, C.; Jackson, J.; Petit, L.; Rivero-Baleine, C.; Richardson, K.

    2010-01-01

    New oxy-sulfo-telluride glasses have been prepared in the Ge-Sb-Te-S-O system employing a two-step melting process which involves the processing of a chalcogenide glass (ChG) and subsequent melting with TeO 2 or Sb 2 O 3 . The progressive incorporation of O at the expense of S was found to increase the density and the glass transition temperature and to decrease the molar volume of the investigated oxy-sulfo-telluride glasses. We also observed a shift of the vis-NIR cut-off wavelength to longer wavelength probably due to changes in Sb coordination within the glass matrix and overall matrix polarizability. Using Raman spectroscopy, correlations have been shown between the formation of Ge- and Sb-based oxysulfide structural units and the S/O ratio. Lastly, two glasses with similar composition (Ge 20 Sb 6 S 64 Te 3 O 7 ) processed by melting the Ge 23 Sb 7 S 70 glass with TeO 2 or the Ge 23 Sb 2 S 72 Te 4 glass with Sb 2 O 3 were found to have slightly different physical, thermal, optical and structural properties. These changes are thought to result mainly from the higher moisture content and sensitivity of the TeO 2 starting materials as compared to that of the Sb 2 O 3 . - Graphical abstract: In this paper, we discuss our most recent findings on the processing and characterization of new ChG glasses prepared with small levels of Te, melted either with TeO 2 or Sb 2 O 3 powders. We explain how these new oxy-sulfo-telluride glasses are prepared and we correlate the physical, thermal and optical properties of the investigated glasses to the structure changes induced by the addition of oxygen in the Ge-Sb-S-Te glass network.

  11. Investigations of portable cadmium telluride (CdTe(Cl)) detectors for clinical studies with radioactive indicators

    International Nuclear Information System (INIS)

    Bojsen, J.

    1985-01-01

    The combination of small, portable γ-radiation-sensitive Cadmium Telluride (CdTE(Cl)) crystal detectors and portable solid state data storage memories makes it feasible to extend the measuring period in a number of clinical investigations based on the use of various radioisotopes and external detection. Blood sampling can be avoided in some cases. Continuous ambulatory monitoring of relevant physiological parameters is practicable, e.g. kidney function (GFR), left ventricular ejection fraction, subcutaneous blood flow, muscle blood flow and insulin absorption in diabetic patients. In the present methodological study the applicability of the 133-Xe washout technique to subcutaneous (s.c.) adipose tissue blood flow (SBF) has been investigated and adapted to the use of CdTe(Cl) detectors attached to the skin surface for the measurement of local 133-Xe-disappearance rate constants (k). Physical characterization of CdTe(Cl) detectors as γ-sensitive devices has been performed, and adequate counting sensitivities were found without detector energy-resolution properties. The CdTe(Cl) detectors are therefore suitable for single indicator studies. The measuring geometry of CdTe(Cl) detectors was studied and compared with that of stationary Sodium Iodide (NaI(Tl)) detectors in both phantom and in vivo investigations. The spatial properties of CdTe(Cl) detectors could to some extent be adjusted by pulse height discrimination and lead collimation. When long-term measurements were complicated by for instance physical activity of the patients, the small CdTe(Cl) detectors in general showed equal or better performance than the heavy and voluminous NaI(Tl) detectors. The free movement of the ambulatory patient and the avoidance of cable connections to stationary data-collecting systems gave improved possibilities for measurements of the relevant parameters. From this point of view, portable CdTe(Cl) detectors must be considered an important advance for radioactivity studies in

  12. A Fumonisins Immunosensor Based on Polyanilino-Carbon Nanotubes Doped with Palladium Telluride Quantum Dots

    Science.gov (United States)

    Masikini, Milua; Mailu, Stephen N.; Tsegaye, Abebaw; Njomo, Njagi; Molapo, Kerileng M.; Ikpo, Chinwe O.; Sunday, Christopher Edozie; Rassie, Candice; Wilson, Lindsay; Baker, Priscilla G. L.; Iwuoha, Emmanuel I.

    2015-01-01

    An impedimetric immunosensor for fumonisins was developed based on poly(2,5-dimethoxyaniline)-multi-wall carbon nanotubes doped with palladium telluride quantum dots onto a glassy carbon surface. The composite was assembled by a layer-by-layer method to form a multilayer film of quantum dots (QDs) and poly(2,5-dimethoxyaniline)-multi-wall carbon nanotubes (PDMA-MWCNT). Preparation of the electrochemical immunosensor for fumonisins involved drop-coating of fumonisins antibody onto the composite modified glassy carbon electrode. The electrochemical impedance spectroscopy response of the FB1 immunosensor (GCE/PT-PDMA-MWCNT/anti-Fms-BSA) gave a linear range of 7 to 49 ng L−1 and the corresponding sensitivity and detection limits were 0.0162 kΩ L ng−1 and 0.46 pg L−1, respectively, hence the limit of detection of the GCE/PT-PDMA-MWCNT immunosensor for fumonisins in corn certified material was calculated to be 0.014 and 0.011 ppm for FB1, and FB2 and FB3, respectively. These results are lower than those obtained by ELISA, a provisional maximum tolerable daily intake (PMTDI) for fumonisins (the sum of FB1, FB2, and FB3) established by the Joint FAO/WHO expert committee on food additives and contaminants of 2 μg kg−1 and the maximum level recommended by the U.S. Food and Drug Administration (FDA) for protection of human consumption (2–4 mg L−1). PMID:25558993

  13. Mercury-Cadmium-Telluride Focal Plane Array Performance Under Non-Standard Operating Conditions

    Science.gov (United States)

    Richardson, Brandon S.; Eastwood, Michael L.; Bruce, Carl F.; Green, Robert O.; Coles, J. B.

    2011-01-01

    This paper highlights a new technique that allows the Teledyne Scientific & Imaging LLC TCM6604A Mercury-Cadmium-Telluride (MCT) Focal Plane Array (FPA) to operate at room temperature. The Teledyne MCT FPA has been a standard in Imaging Spectroscopy since its creation in the 1980's. This FPA has been used in applications ranging from space instruments such as CRISM, M3 and ARTEMIS to airborne instruments such as MaRS and the Next Generation AVIRIS Instruments1. Precise focal plane alignment is always a challenge for such instruments. The current FPA alignment process results in multiple cold cycles requiring week-long durations, thereby increasing the risk and cost of a project. These alignment cycles are necessary because optimal alignment is approached incrementally and can only be measured with the FPA and Optics at standard operating conditions, requiring a cold instrument. Instruments using this FPA are normally cooled to temperatures below 150K for the MCT FPA to properly function. When the FPA is run at higher temperatures the dark current increases saturating the output. This paper covers the prospect of warm MCT FPA operation from a theoretical and experimental perspective. We discuss the empirical models and physical laws that govern MCT material properties and predict the optimal settings that will result in the best MCT PA performance at 300K. Theoretical results are then calculated for the proposed settings. We finally present the images and data obtained using the actual system with the warm MCT FPA settings. The paper concludes by emphasizing the strong positive correlation between the measured values and the theoretical results.

  14. Spark plasma sintered bismuth telluride-based thermoelectric materials incorporating dispersed boron carbide

    Energy Technology Data Exchange (ETDEWEB)

    Williams, H.R., E-mail: hugo.williams@leicester.ac.uk [Department of Engineering, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Ambrosi, R.M. [Space Research Centre, Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Chen, K. [School of Engineering and Materials Science, Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom); Friedman, U. [Department of Engineering, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Ning, H.; Reece, M.J. [School of Engineering and Materials Science, Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom); Robbins, M.C.; Simpson, K. [European Thermodynamics Ltd., 8 Priory Business Park, Wistow Road, Kibworth LE8 0R (United Kingdom); Stephenson, K. [European Space Agency, ESTEC TEC-EP, Keplerlaan 1, 2201AZ Noordwijk (Netherlands)

    2015-03-25

    Highlights: • Nano-B{sub 4}C reinforced Bi{sub 0.5}Sb{sub 1.5}Te{sub 3} p-type thermoelectric produced by SPS. • Addition of B{sub 4}C up to 0.2 vol% to SPS’d material has little effect on zT. • Vickers hardness improved by 27% by adding 0.2 vol% B{sub 4}C. • Fracture toughness of SPS material: K{sub IC} = 0.80 MPa m{sup 1/2} by SEVNB. • Mechanical properties much better than commercial directionally solidified material. - Abstract: The mechanical properties of bismuth telluride based thermoelectric materials have received much less attention in the literature than their thermoelectric properties. Polycrystalline p-type Bi{sub 0.5}Sb{sub 1.5}Te{sub 3} materials were produced from powder using spark plasma sintering (SPS). The effects of nano-B{sub 4}C addition on the thermoelectric performance, Vickers hardness and fracture toughness were measured. Addition of 0.2 vol% B{sub 4}C was found to have little effect on zT but increased hardness by approximately 27% when compared to polycrystalline material without B{sub 4}C. The K{sub IC} fracture toughness of these compositions was measured as 0.80 MPa m{sup 1/2} by Single-Edge V-Notched Beam (SEVNB). The machinability of polycrystalline materials produced by SPS was significantly better than commercially available directionally solidified materials because the latter is limited by cleavage along the crystallographic plane parallel to the direction of solidification.

  15. The crystal structures and powder diffraction patterns of the uranium tellurides

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, R.L. (State Univ. of New York, Alfred, NY (USA). Inst. of Ceramic Superconductivity); Nichols, M.C.; Boehme, D.R. (Sandia National Labs., Livermore, CA (USA))

    1990-10-03

    A critical review of all of the reported structures and powder diffraction patterns in the uranium telluride system has been undertaken. Structures that are correct: Cubic -- UTe: no experimental pattern exists. Retain calculated 15--865. Cubic --U{sub 3}Te{sub 4}: retain the poor quality 12--610 but adopt the pattern calculated here. Cubic U{sub 2}Te{sub 3}: no experimental pattern exists. Adopt pattern calculated here. Orthorhombic UTe{sub 2}: Adopt the new pattern of Boehme et al. Monoclinic {alpha}UTe{sub 3} Adopt the new pattern of Boehme et al. Monoclinic {alpha}UTe{sub 3} Adopt the new pattern of Boehme et al. Orthorhombic {beta}UTe{sub 3}: Adopt pattern calculated here. Orthorhombic UTe{sub 5}: Adopt the new pattern of Boehme et al. Structures in need of refinement: Orthorhombic U{sub 2}Te{sub 3}:Adopt pattern calculated here over 34--807. Hexagonal U{sub 7}Te{sub 12}: Adopt pattern calculated here but retain 24--1368. Orthorhombic UTe{sub 1.78}: Adopt pattern calculated here and retain our modified 21--1404 reported for U{sub 4}Te{sub 7}. Orthorhombic UTe{sub 2.5}: Adopt pattern calculated here. Orthorhombic UTe{sub 3.4}: Accept recent pattern of Boehme et al. Phases for which no structures or reliable patterns exist: Orthorhombic U{sub 3}Te{sub 4}: no published pattern. Tetragonal U{sub 3}Te{sub 5}: three patterns 21--1407, 34--766 and 34--896 exit but all are of very poor quality. Phases which probably do not exist: Tetragonal UTe{sub 1.78}, Tetragonal UTe{sub 2}, Cubic UTe{sub 2} U{sub 3}Te{sub 7}(21--1402), U{sub 3}Te{sub 8}(21--1406).

  16. Laser Photolysis and Thermolysis of Organic Selenides and Tellurides for Chemical Gas-phase Deposition of Nanostructured Materials

    Directory of Open Access Journals (Sweden)

    Josef Pola

    2009-03-01

    Full Text Available Laser radiation-induced decomposition of gaseous organic selenides and tellurides resulting in chemical deposition of nanostructured materials on cold surfaces is reviewed with regard to the mechanism of the gas-phase decomposition and properties of the deposited materials. The laser photolysis and laser thermolysis of the Se and Te precursors leading to chalcogen deposition can also serve as a useful approach to nanostructured chalcogen composites and IVA group (Si, Ge, Sn element chalcogenides provided that it is carried out simultaneously with laser photolysis or thermolysis of polymer and IVA group element precursor.

  17. Reaction of 1-bromo-3-chloropropane with tellurium and dimethyl telluride in the system of hydrazine hydrate-alkali

    International Nuclear Information System (INIS)

    Russavskaya, N.V.; Levanova, E.P.; Sukhomazova, Eh.N.; Grabel'nykh, V.A.; Elaev, A.V.; Klyba, L.V.; Zhanchipova, E.R.; Albanov, A.I.; Korotaeva, I.M.; Toryashinova, D.S.D.; Korchevin, N.A.

    2006-01-01

    A synthesis of oligomeric substance of thiocol type, the poly(trimethyleneditelluride), from 1-bromo-3-chloropropane and elemental tellurium is performed using a hydrazine hydrate-alkali system. Reductive splitting of the tellurocol followed by alkylation with methyl iodide give rise to preparation of bis(methyltelluro)propane, which was synthesized also from dimethyl telluride and 1,3-dihalopropanes using the N 2 H 4 ·H 2 O/KOH system. The reaction products were characterized by elementary analysis, NMR, and IR spectra. Mass spectra of the synthesized low molecular weight organotellurium compounds are considered [ru

  18. Aluminium or copper substrate panel for selective absorption of solar energy

    Science.gov (United States)

    Roberts, M. L.; Sharpe, M. H.; Krupnick, A. C. (Inventor)

    1979-01-01

    A method for making panels which selectively absorb solar energy is disclosed. The panels are comprised of an aluminum substrate, a layer of zinc thereon, a layer of nickel over the zinc layer and an outer layer of solar energy absorbing nickel oxide or a copper substrate with a layer of nickel thereon and a layer of solar energy absorbing nickel oxide distal from the copper substrate.

  19. Chloroquine is a zinc ionophore.

    Directory of Open Access Journals (Sweden)

    Jing Xue

    Full Text Available Chloroquine is an established antimalarial agent that has been recently tested in clinical trials for its anticancer activity. The favorable effect of chloroquine appears to be due to its ability to sensitize cancerous cells to chemotherapy, radiation therapy, and induce apoptosis. The present study investigated the interaction of zinc ions with chloroquine in a human ovarian cancer cell line (A2780. Chloroquine enhanced zinc uptake by A2780 cells in a concentration-dependent manner, as assayed using a fluorescent zinc probe. This enhancement was attenuated by TPEN, a high affinity metal-binding compound, indicating the specificity of the zinc uptake. Furthermore, addition of copper or iron ions had no effect on chloroquine-induced zinc uptake. Fluorescent microscopic examination of intracellular zinc distribution demonstrated that free zinc ions are more concentrated in the lysosomes after addition of chloroquine, which is consistent with previous reports showing that chloroquine inhibits lysosome function. The combination of chloroquine with zinc enhanced chloroquine's cytotoxicity and induced apoptosis in A2780 cells. Thus chloroquine is a zinc ionophore, a property that may contribute to chloroquine's anticancer activity.

  20. Innovative uses for zinc in dermatology.

    Science.gov (United States)

    Bae, Yoon Soo; Hill, Nikki D; Bibi, Yuval; Dreiher, Jacob; Cohen, Arnon D

    2010-07-01

    Severe zinc deficiency states, such as acrodermatitis enteropathica, are associated with a variety of skin manifestations, such as perioral, acral, and perineal dermatitis. These syndromes can be reversed with systemic zinc repletion. In addition to skin pathologies that are clearly zinc-dependent, many dermatologic conditions (eg, dandruff, acne, and diaper rash) have been associated and treated with zinc. Success rates for treatment with zinc vary greatly depending on the disease, mode of administration, and precise zinc preparation used. With the exception of systemic zinc deficiency states, there is little evidence that convincingly demonstrates the efficacy of zinc as a reliable first-line treatment for most dermatologic conditions. However, zinc may be considered as an adjunctive treatment modality. Further research is needed to establish the indications for zinc treatment in dermatology, optimal mode of zinc delivery, and best type of zinc compound to be used. Copyright 2010 Elsevier Inc. All rights reserved.

  1. Transformation of zinc hydroxide chloride monohydrate to crystalline zinc oxide.

    Science.gov (United States)

    Moezzi, Amir; Cortie, Michael; McDonagh, Andrew

    2016-04-25

    Thermal decomposition of layered zinc hydroxide double salts provides an interesting alternative synthesis for particles of zinc oxide. Here, we examine the sequence of changes occurring as zinc hydroxide chloride monohydrate (Zn5(OH)8Cl2·H2O) is converted to crystalline ZnO by thermal decomposition. The specific surface area of the resultant ZnO measured by BET was 1.3 m(2) g(-1). A complicating and important factor in this process is that the thermal decomposition of zinc hydroxide chloride is also accompanied by the formation of volatile zinc-containing species under certain conditions. We show that this volatile compound is anhydrous ZnCl2 and its formation is moisture dependent. Therefore, control of atmospheric moisture is an important consideration that affects the overall efficiency of ZnO production by this process.

  2. Uptake and partitioning of zinc in Lemnaceae.

    Science.gov (United States)

    Lahive, Elma; O'Callaghan, Michael J A; Jansen, Marcel A K; O'Halloran, John

    2011-11-01

    Macrophytes provide food and shelter for aquatic invertebrates and fish, while also acting as reservoirs for nutrients and trace elements. Zinc accumulation has been reported for various Lemnaceae species. However, comparative accumulation across species and the link between zinc accumulation and toxicity are poorly understood. Morphological distribution and cellular storage, in either bound or soluble form, are important for zinc tolerance. This study shows differences in the uptake and accumulation of zinc by three duckweed species. Landoltia punctata and Lemna minor generally accumulated more zinc than Lemna gibba. L. minor, but not L. gibba or L. punctata, accumulated greater concentrations of zinc in roots compared to fronds when exposed to high levels of zinc. The proportion of zinc stored in the bound form relative to the soluble-form was higher in L. minor. L. punctata accumulated greater concentrations of zinc in fronds compared to roots and increased the proportion of zinc it stored in the soluble form, when exposed to high zinc levels. L. gibba is the only species that significantly accumulated zinc at low concentrations, and was zinc-sensitive. Overall, internal zinc concentrations showed no consistent correlation with toxic effect. We conclude that relationships between zinc toxicity and uptake and accumulation are species specific reflecting, among others, zinc distribution and storage. Differences in zinc distribution and storage are also likely to have implications for zinc bioavailability and trophic mobility.

  3. Inhibitory zinc-enriched terminals in mouse spinal cord

    DEFF Research Database (Denmark)

    Danscher, G; Jo, S M; Varea, E

    2001-01-01

    The ultrastructural localization of zinc transporter-3, glutamate decarboxylase and zinc ions in zinc-enriched terminals in the mouse spinal cord was studied by zinc transporter-3 and glutamate decarboxylase immunohistochemistry and zinc selenium autometallography, respectively.The distribution...

  4. Zinc: an essential oligoelement

    OpenAIRE

    Rubio, C.; González Weller, D.; Martín-Izquierdo, R. E.; Revert, C.; Rodríguez, I.; Hardisson, A.

    2007-01-01

    En este artículo se hace una revisión exhaustiva del zinc, elemento metálico esencial para el funcionamiento del organismo. Repasamos y reflejamos aspectos relacionados con la farmacocinética, con las fuentes dietéticas más importantes, así como las IDR (Ingestas Dietéticas Recomendadas) del mismo. También se hace mención a los signos y síntomas relacionados tanto con una ingesta deficiente, como con posibles efectos tóxicos, derivados de ingestas excesivas.This article comprehensively review...

  5. Cadmium and zinc

    International Nuclear Information System (INIS)

    Safaya, N.M.; McLean, J.E.; Halverson, G.A.

    1987-01-01

    Cadmium and zinc are naturally occurring trace metals that are often considered together because of their close geochemical association and similarities in chemical reactivity. The loss of two electrons from an atom of Cd or Zn imparts to each an electron configuration with completely filled d orbitals; this results in a highly stable 2/sup +/ oxidation state. But Cd and Zn differ greatly in their significance to biological systems. Whereas Zn is an essential nutrient for plants, animals, and humans, Cd is best known for its toxicity to plants and as a causative agent of several disease syndromes in animals and humans

  6. Solar building

    OpenAIRE

    Zhang, Luxin

    2014-01-01

    In my thesis I describe the utilization of solar energy and solar energy with building integration. In introduction it is also mentioned how the solar building works, trying to make more people understand and accept the solar building. The thesis introduces different types of solar heat collectors. I compared the difference two operation modes of solar water heating system and created examples of solar water system selection. I also introduced other solar building applications. It is conv...

  7. 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.

  8. 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.

  9. Comparative study about Al-doped zinc oxide thin films deposited by Pulsed Electron Deposition and Radio Frequency Magnetron Sputtering as Transparent Conductive Oxide for Cu(In,Ga)Se{sub 2}-based solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Pattini, F., E-mail: pattini@imem.cnr.it [IMEM-CNR, Institute of Materials for Electronics and Magnetism, Parco Area delle Scienze 37/A, 43124 Parma (Italy); Annoni, F.; Bissoli, F.; Bronzoni, M. [IMEM-CNR, Institute of Materials for Electronics and Magnetism, Parco Area delle Scienze 37/A, 43124 Parma (Italy); Garcia, J.P. [Delft University of Technology, Faculty of Applied Sciences, Delft Product and Process Design Institute, Julianalaan 67, 2628 BC Delft (Netherlands); Gilioli, E.; Rampino, S. [IMEM-CNR, Institute of Materials for Electronics and Magnetism, Parco Area delle Scienze 37/A, 43124 Parma (Italy)

    2015-05-01

    In this study, a comparison between Al-doped ZnO (AZO) as Transparent Conductive Oxide for Cu(In,Ga)Se{sub 2}-based solar cells grown by Pulsed Electron Deposition (PED) and Radio Frequency Magnetron Sputtering (RFMS) was performed. PED yielded polycrystalline [002] mono-oriented thin films with low electrical resistivity and high optical transparency with heater temperatures ranging from room temperature (RT) to 250 °C. The electrical resistivity of these films can be tuned by varying the heater temperature, reaching a minimum value of 3.5 × 10{sup −4} Ωcm at 150 °C and an average transmittance over 90% in the visible range. An AZO film grown at RT was deposited by PED on an actual Cu(In,Ga)Se{sub 2}-based solar cell, resulting to an efficiency value of 15.2% on the best device. This result clearly shows that PED is a suitable technique for growing ZnO-based thin films for devices/applications where low deposition temperature is required. On the other hand, an optimized AZO thin film front contact for thin film solar cells was studied and fabricated via RFMS. The parameters of this technique were tweaked to obtain highly conductive and transparent AZO thin films. The lowest resistivity value of 3.7 × 10{sup −4} Ωcm and an average transmittance of 86% in the 400-1100 nm wavelength range was obtained with a heater temperature of 250 °C. A thick sputtered AZO film was deposited at RT onto an identical cell used for PED-grown AZO, reaching the highest conversion efficiency value of 14.7%. In both cases, neither antireflection coatings nor pure ZnO layer was used. - Highlights: • Pulsed Electron Deposition (PED) lets high quality films grow at low temperature. • Al:ZnO (AZO) thin films grown by PED present high optical and electrical quality. • AZO electrical resistivity can be tuned from 10{sup −4} to 10{sup −2} Ωcm in proper condition. • Cu(In,Ga)Se{sub 2}-based simplified solar cells achieved efficiency of 15.2% for PED-grown AZO.

  10. Zinc in Infection and Inflammation

    Directory of Open Access Journals (Sweden)

    Nour Zahi Gammoh

    2017-06-01

    Full Text Available Micronutrient homeostasis is a key factor in maintaining a healthy immune system. Zinc is an essential micronutrient that is involved in the regulation of the innate and adaptive immune responses. The main cause of zinc deficiency is malnutrition. Zinc deficiency leads to cell-mediated immune dysfunctions among other manifestations. Consequently, such dysfunctions lead to a worse outcome in the response towards bacterial infection and sepsis. For instance, zinc is an essential component of the pathogen-eliminating signal transduction pathways leading to neutrophil extracellular traps (NET formation, as well as inducing cell-mediated immunity over humoral immunity by regulating specific factors of differentiation. Additionally, zinc deficiency plays a role in inflammation, mainly elevating inflammatory response as well as damage to host tissue. Zinc is involved in the modulation of the proinflammatory response by targeting Nuclear Factor Kappa B (NF-κB, a transcription factor that is the master regulator of proinflammatory responses. It is also involved in controlling oxidative stress and regulating inflammatory cytokines. Zinc plays an intricate function during an immune response and its homeostasis is critical for sustaining proper immune function. This review will summarize the latest findings concerning the role of this micronutrient during the course of infections and inflammatory response and how the immune system modulates zinc depending on different stimuli.

  11. Zinc in Infection and Inflammation.

    Science.gov (United States)

    Gammoh, Nour Zahi; Rink, Lothar

    2017-06-17

    Micronutrient homeostasis is a key factor in maintaining a healthy immune system. Zinc is an essential micronutrient that is involved in the regulation of the innate and adaptive immune responses. The main cause of zinc deficiency is malnutrition. Zinc deficiency leads to cell-mediated immune dysfunctions among other manifestations. Consequently, such dysfunctions lead to a worse outcome in the response towards bacterial infection and sepsis. For instance, zinc is an essential component of the pathogen-eliminating signal transduction pathways leading to neutrophil extracellular traps (NET) formation, as well as inducing cell-mediated immunity over humoral immunity by regulating specific factors of differentiation. Additionally, zinc deficiency plays a role in inflammation, mainly elevating inflammatory response as well as damage to host tissue. Zinc is involved in the modulation of the proinflammatory response by targeting Nuclear Factor Kappa B (NF-κB), a transcription factor that is the master regulator of proinflammatory responses. It is also involved in controlling oxidative stress and regulating inflammatory cytokines. Zinc plays an intricate function during an immune response and its homeostasis is critical for sustaining proper immune function. This review will summarize the latest findings concerning the role of this micronutrient during the course of infections and inflammatory response and how the immune system modulates zinc depending on different stimuli.

  12. Solar energy

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This chapter discusses the role solar energy may have in the energy future of the US. The topics discussed in the chapter include the solar resource, solar architecture including passive solar design and solar collectors, solar-thermal concentrating systems including parabolic troughs and dishes and central receivers, photovoltaic cells including photovoltaic systems for home use, and environmental, health and safety issues

  13. Inhibition of autophagy contributes to the toxicity of cadmium telluride quantum dots in Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Fan J

    2016-07-01

    Full Text Available Junpeng Fan,1–4 Ming Shao,1–4 Lu Lai,3–5 Yi Liu,3–5 Zhixiong Xie1–4,6 1College of Life Sciences, Wuhan University, 2Hubei Provincial Cooperative Innovation Center of Industrial Fermentation,3State Key Laboratory of Virology, 4Key Laboratory of Analytical Chemistry for Biology and Medicine (MOE, 5College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 6School of Life Science and Technology, Hubei Engineering University, Xiaogan, People’s Republic of China Abstract: Cadmium telluride quantum dots (CdTe QDs are used as near-infrared probes in biologic and medical applications, but their cytological effects and mechanism of potential toxicity are still unclear. In this study, we evaluated the toxicity of CdTe QDs of different sizes and investigated their mechanism of toxicity in the yeast Saccharomyces cerevisiae. A growth inhibition assay revealed that orange-emitting CdTe (O-CdTe QDs (half inhibitory concentration [IC50] =59.44±12.02 nmol/L were more toxic than green-emitting CdTe QDs (IC50 =186.61±19.74 nmol/L to S. cerevisiae. Further studies on toxicity mechanisms using a transmission electron microscope and green fluorescent protein tagged Atg8 processing assay revealed that O-CdTe QDs could partially inhibit autophagy at a late stage, which differs from the results reported in mammalian cells. Moreover, autophagy inhibited at a late stage by O-CdTe QDs could be partially recovered by enhancing autophagy with rapamycin (an autophagy activator, combined with an increased number of living cells. These results indicate that inhibition of autophagy acts as a toxicity mechanism of CdTe QDs in S. cerevisiae. This work reports a novel toxicity mechanism of CdTe QDs in yeast and provides valuable information on the effect of CdTe QDs on the processes of living cells. Keywords: CdTe quantum dots, Saccharomyces cerevisiae, toxicity, autophagy

  14. Enhanced thermoelectric properties of metal film on bismuth telluride-based materials

    International Nuclear Information System (INIS)

    Chao, Wen Hsuan; Chen, Yi Ray; Tseng, Shih Chun; Yang, Ping Hsing; Wu, Ren Jye; Hwang, Jenn Yeu

    2014-01-01

    Diffusion barriers have a significant influence on the reliability and life time of thermoelectric modules. Although nickel is commonly used as a diffusion barrier in commercial thermoelectric modules, several studies have verified that Ni migrates to bismuth telluride-based material during high temperature cycles and causes a loss in efficacy. In this paper, the influence of metal layers coated to p-type and n-type Bi 2 Te 3 on the interface characterization and thermoelectric property is studied using a RF magnetron sputtering. The findings from this study demonstrate the structural and thermoelectric properties of p-type and n-type Bi 2 Te 3 coated with different metal layers. The crystalline phase and compositional change of the interface between the Bi 2 Te 3 materials and the metal layers were determined using an X-ray diffractometer and scanning electron microscopy with energy dispersive spectroscopy. Formation of NiTe was observed in the sample of Ni/p-type Bi 2 Te 3 based films post-annealed in an N 2 atmosphere at 200 °C. In contrast, no Co x Te y was formed in the sample of Co/p-type Bi 2 Te 3 based films post-annealed at 200 °C. For as-deposited Ni/p-type and n-type Bi 2 Te 3 based legs, the Ni slightly diffused into the Bi 2 Te 3 based legs. A similar phenomenon also occurred in the as-deposited Co/p-type and n-type Bi 2 Te 3 based legs. The Seebeck coefficients of the Co contacts on the Bi 2 Te 3 based material displayed better behavior than those of the Ni contacts on the Bi 2 Te 3 based legs. Thus Co could be a suitable diffusion barrier for bulk Bi 2 Te 3 based material. The observed effects on the thermoelectric and structural properties of metal/Bi 2 Te 3 based material are crucial for understanding the interface between the diffusion barrier and thermoelectric materials. - Highlights: • Interface characterization of metal coated to p-type and n-type Bi 2 Te 3 is studied. • We examined the phase transformation of metal/Bi 2 Te 3 based films

  15. Control of p-type and n-type thermoelectric properties of bismuth telluride thin films by combinatorial sputter coating technology

    International Nuclear Information System (INIS)

    Goto, Masahiro; Sasaki, Michiko; Xu, Yibin; Zhan, Tianzhuo; Isoda, Yukihiro; Shinohara, Yoshikazu

    2017-01-01

    Highlights: • p- and n-type bismuth telluride thin films have been synthesized using a combinatorial sputter coating system (COSCOS) while changing only one of the experimental conditions, the RF power. • The dimensionless figure of merit (ZT) was optimized by the technique. • The fabrication of a Π-structured TE device was demonstrated. - Abstract: p- and n-type bismuth telluride thin films have been synthesized by using a combinatorial sputter coating system (COSCOS). The crystal structure and crystal preferred orientation of the thin films were changed by controlling the coating condition of the radio frequency (RF) power during the sputter coating. As a result, the p- and n-type films and their dimensionless figure of merit (ZT) were optimized by the technique. The properties of the thin films such as the crystal structure, crystal preferred orientation, material composition and surface morphology were analyzed by X-ray diffraction, energy-dispersive X-ray spectroscopy and atomic force microscopy. Also, the thermoelectric properties of the Seebeck coefficient, electrical conductivity and thermal conductivity were measured. ZT for n- and p-type bismuth telluride thin films was found to be 0.27 and 0.40 at RF powers of 90 and 120 W, respectively. The proposed technology can be used to fabricate thermoelectric p–n modules of bismuth telluride without any doping process.

  16. Control of p-type and n-type thermoelectric properties of bismuth telluride thin films by combinatorial sputter coating technology

    Energy Technology Data Exchange (ETDEWEB)

    Goto, Masahiro, E-mail: goto.masahiro@nims.go.jp [Thermoelectric Materials Group, Center for Green Research on Energy and Environmental Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Thermal Management and Thermoelectric Materials Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Sasaki, Michiko [Thermal Management and Thermoelectric Materials Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Xu, Yibin [Thermal Management and Thermoelectric Materials Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Materials Database Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Zhan, Tianzhuo [Thermal Management and Thermoelectric Materials Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Isoda, Yukihiro [Thermoelectric Materials Group, Center for Green Research on Energy and Environmental Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Shinohara, Yoshikazu [Thermoelectric Materials Group, Center for Green Research on Energy and Environmental Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Thermal Management and Thermoelectric Materials Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan)

    2017-06-15

    Highlights: • p- and n-type bismuth telluride thin films have been synthesized using a combinatorial sputter coating system (COSCOS) while changing only one of the experimental conditions, the RF power. • The dimensionless figure of merit (ZT) was optimized by the technique. • The fabrication of a Π-structured TE device was demonstrated. - Abstract: p- and n-type bismuth telluride thin films have been synthesized by using a combinatorial sputter coating system (COSCOS). The crystal structure and crystal preferred orientation of the thin films were changed by controlling the coating condition of the radio frequency (RF) power during the sputter coating. As a result, the p- and n-type films and their dimensionless figure of merit (ZT) were optimized by the technique. The properties of the thin films such as the crystal structure, crystal preferred orientation, material composition and surface morphology were analyzed by X-ray diffraction, energy-dispersive X-ray spectroscopy and atomic force microscopy. Also, the thermoelectric properties of the Seebeck coefficient, electrical conductivity and thermal conductivity were measured. ZT for n- and p-type bismuth telluride thin films was found to be 0.27 and 0.40 at RF powers of 90 and 120 W, respectively. The proposed technology can be used to fabricate thermoelectric p–n modules of bismuth telluride without any doping process.

  17. Zinc as a Gatekeeper of Immune Function

    Directory of Open Access Journals (Sweden)

    Inga Wessels

    2017-11-01

    Full Text Available After the discovery of zinc deficiency in the 1960s, it soon became clear that zinc is essential for the function of the immune system. Zinc ions are involved in regulating intracellular signaling pathways in innate and adaptive immune cells. Zinc homeostasis is largely controlled via the expression and action of zinc “importers” (ZIP 1–14, zinc “exporters” (ZnT 1–10, and zinc-binding proteins. Anti-inflammatory and anti-oxidant properties of zinc have long been documented, however, underlying mechanisms are still not entirely clear. Here, we report molecular mechanisms underlying the development of a pro-inflammatory phenotype during zinc deficiency. Furthermore, we describe links between altered zinc homeostasis and disease development. Consequently, the benefits of zinc supplementation for a malfunctioning immune system become clear. This article will focus on underlying mechanisms responsible for the regulation of cellular signaling by alterations in zinc homeostasis. Effects of fast zinc flux, intermediate “zinc waves”, and late homeostatic zinc signals will be discriminated. Description of zinc homeostasis-related effects on the activation of key signaling molecules, as well as on epigenetic modifications, are included to emphasize the role of zinc as a gatekeeper of immune function.

  18. Cathodic hydrogen charging of zinc

    International Nuclear Information System (INIS)

    Panagopoulos, C.N.; Georgiou, E.P.; Chaliampalias, D.

    2014-01-01

    Highlights: •Incorporation of hydrogen into zinc and formation of zinc hydrides. •Investigation of surface residual stresses due to hydrogen diffusion. •Effect of hydrogen diffusion and hydride formation on mechanical properties of Zn. •Hydrogen embrittlement phenomena in zinc. -- Abstract: The effect of cathodic hydrogen charging on the structural and mechanical characteristics of zinc was investigated. Hardening of the surface layers of zinc, due to hydrogen incorporation and possible formation of ZnH 2 , was observed. In addition, the residual stresses brought about by the incorporation of hydrogen atoms into the metallic matrix, were calculated by analyzing the obtained X-ray diffraction patterns. Tensile testing of the as-received and hydrogen charged specimens revealed that the ductility of zinc decreased significantly with increasing hydrogen charging time, for a constant value of charging current density, and with increasing charging current density, for a constant value of charging time. However, the ultimate tensile strength of this material was slightly affected by the hydrogen charging procedure. The cathodically charged zinc exhibited brittle transgranular fracture at the surface layers and ductile intergranular fracture at the deeper layers of the material

  19. Electrodeposition of zinc--nickel alloys coatings

    Energy Technology Data Exchange (ETDEWEB)

    Dini, J W; Johnson, H R

    1977-10-01

    One possible substitute for cadmium in some applications is a zinc--nickel alloy deposit. Previous work by others showed that electrodeposited zinc--nickel coatings containing about 85 percent zinc and 15 percent nickel provided noticeably better corrosion resistance than pure zinc. Present work which supports this finding also shows that the corrosion resistance of the alloy deposit compares favorably with cadmium.

  20. Zinc and cadmium monosalicylates

    International Nuclear Information System (INIS)

    Kharitonov, Yu.Ya.; Tujebakhova, Z.K.

    1984-01-01

    Zinc and cadmium monosalicylates of the composition MSal, where M-Zn or Cd, Sal - twice deprotonated residue of salicylic acid O-HOC 6 H 4 COOH (H 2 Sal), are singled out and characterized. When studying thermograms, thermogravigrams, IR absorption spectra, roentgenograms of cadmium salicylate compounds (Cd(OC 6 H 4 COO) and products of their thepmal transformations, the processes of thermal decomposition of the compounds have been characterized. The process of cadmium monosalicylate decomposition takes place in one stage. Complete loss of salicylate acido group occurs in the range of 320-460 deg. At this decomposition stage cadmium oxide is formed. A supposition is made that cadmium complex has tetrahedral configuration, at that, each salicylate group plays the role of tetradentate-bridge ligand. The compound evidently has a polymer structure

  1. Reduction of arsenite-enhanced ultraviolet radiation-induced DNA damage by supplemental zinc

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, Karen L.; King, Brenee S.; Sandoval, Monica M.; Liu, Ke Jian; Hudson, Laurie G., E-mail: lhudson@salud.unm.edu

    2013-06-01

    Arsenic is a recognized human carcinogen and there is evidence that arsenic augments the carcinogenicity of DNA damaging agents such as ultraviolet radiation (UVR) thereby acting as a co-carcinogen. Inhibition of DNA repair is one proposed mechanism to account for the co-carcinogenic actions of arsenic. We and others find that arsenite interferes with the function of certain zinc finger DNA repair proteins. Furthermore, we reported that zinc reverses the effects of arsenite in cultured cells and a DNA repair target protein, poly (ADP-ribose) polymerase-1. In order to determine whether zinc ameliorates the effects of arsenite on UVR-induced DNA damage in human keratinocytes and in an in vivo model, normal human epidermal keratinocytes and SKH-1 hairless mice were exposed to arsenite, zinc or both before solar-simulated (ss) UVR exposure. Poly (ADP-ribose) polymerase activity, DNA damage and mutation frequencies at the Hprt locus were measured in each treatment group in normal human keratinocytes. DNA damage was assessed in vivo by immunohistochemical staining of skin sections isolated from SKH-1 hairless mice. Cell-based findings demonstrate that ssUVR-induced DNA damage and mutagenesis are enhanced by arsenite, and supplemental zinc partially reverses the arsenite effect. In vivo studies confirm that zinc supplementation decreases arsenite-enhanced DNA damage in response to ssUVR exposure. From these data we can conclude that zinc offsets the impact of arsenic on ssUVR-stimulated DNA damage in cells and in vivo suggesting that zinc supplementation may provide a strategy to improve DNA repair capacity in arsenic exposed human populations. - Highlights: • Low levels of arsenite enhance UV-induced DNA damage in human keratinocytes. • UV-initiated HPRT mutation frequency is enhanced by arsenite. • Zinc supplementation offsets DNA damage and mutation frequency enhanced by arsenite. • Zinc-dependent reduction of arsenite enhanced DNA damage is confirmed in vivo.

  2. Irradiation-induced doping of Bismuth Telluride Bi2Te3

    International Nuclear Information System (INIS)

    Rischau, Carl Willem

    2014-01-01

    Bismuth Telluride Bi 2 Te 3 has attracted enormous attention because of its thermoelectric and topological insulator properties. Regarding its bulk band structure Bi 2 Te 3 is a band insulator with an energy gap of around 150-170 meV. However, the native anti-site defects that are present in real samples always dope this band insulator and shift the chemical potential into the valence or conduction band. In this PhD, the Fermi surface of as-grown and electron irradiated p-type Bi 2 Te 3 single crystals has been investigated extensively using electrical transport experiments. For moderate hole concentrations (p ∼< 5 x 10 18 cm -3 ), it is confirmed that electrical transport can be explained by a six-valley model and the presence of strong Zeeman-splitting. At high doping levels (p≅5 x 10 18 cm -3 ), the hole concentrations determined from Hall and Shubnikov-de Haas (SdH) effect differ significantly which is attributed to an impurity/defect band introduced by the anti-site defects. In this work, we show that it is possible to dope p-type Bi 2 Te 3 in a very controlled manner using electron-irradiation by performing detailed in- and ex-situ electrical transport studies on samples irradiated at room and at low temperatures with 2.5 MeV electrons. These studies show that the defects induced at both irradiation temperatures act as electron donors and can thus be used to convert the conduction from p- to n-type. The point of optimal compensation is accompanied by an increase of the low-temperature resistivity by several orders of magnitude. Irradiation at room temperature showed that both the p-type samples obtained after irradiation to intermediate doses as well as the samples in which the conduction has been converted to n-type by irradiation, still have a well defined Fermi surface as evidenced by SdH oscillations. By studying the Hall coefficient in-situ during low temperature electron irradiation, the coexistence of electron- and hole-type carriers was evidenced

  3. Maternal Zinc Intakes and Homeostatic Adjustments during Pregnancy and Lactation

    OpenAIRE

    Donangelo, Carmen Marino; King, Janet C.

    2012-01-01

    Zinc plays critical roles during embryogenesis, fetal growth, and milk secretion, which increase the zinc need for pregnancy and lactation. Increased needs can be met by increasing the dietary zinc intake, along with making homeostatic adjustments in zinc utilization. Potential homeostatic adjustments include changes in circulating zinc, increased zinc absorption, decreased zinc losses, and changes in whole body zinc kinetics. Although severe zinc deficiency during pregnancy has devastating e...

  4. Effect of zinc from zinc sulfate on trace mineral concentrations of milk ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-11-16

    Nov 16, 2009 ... It suggests that supplementation of ewes diet with zinc sulfate could be an effective way to increase zinc ... alkaline phosphates activity. Zinc supplements were .... Similar results have been reported previously when dairy cows.

  5. Studies on nanocrystalline zinc coating

    Indian Academy of Sciences (India)

    Wintec

    The particles size was also characterized by TEM analysis. Keywords. Electrochemical ... netic materials for magnetic recording, and electrocatalyst for hydrogen .... polarization behaviour was studied in the test electrolyte for zinc deposit of ...

  6. Technical evaluation of Solar Cells, Inc., CdTe module and array at NREL

    Energy Technology Data Exchange (ETDEWEB)

    Kroposki, B.; Strand, T.; Hansen, R. [National Renewable Energy Lab., Golden, CO (United States); Powell, R.; Sasala, R. [Solar Cells, Inc., Toledo, OH (United States)

    1996-05-01

    The Engineering and Technology Validation Team at the National Renewable Energy Laboratory (NREL) conducts in-situ technical evaluations of polycrystalline thin-film photovoltaic (PV) modules and arrays. This paper focuses on the technical evaluation of Solar Cells, Inc., (SCI) cadmium telluride (CdTe) module and array performance by attempting to correlate individual module and array performance. This is done by examining the performance and stability of the modules and array over a period of more than one year. Temperature coefficients for module and array parameters (P{sub max}, V{sub oc}, V{sub max}, I{sub sc}, I{sub max}) are also calculated.

  7. Solar Features - Solar Flares

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A solar flare is a short-lived sudden increase in the intensity of radiation emitted in the neighborhood of sunspots. For many years it was best monitored in the...

  8. Organically pillared layered zinc hydroxides

    International Nuclear Information System (INIS)

    Kongshaug, K.O.; Fjellvaag, Helmer

    2004-01-01

    The two organically pillared layered zinc hydroxides [Zn 2 (OH) 2 (ndc)], CPO-6, and [Zn 3 (OH) 4 (bpdc)], CPO-7, were obtained in hydrothermal reactions between 2,6-naphthalenedicarboxylic acid (ndc) and zinc nitrate (CPO-6) and 4,4'biphenyldicarboxylate (bpdc) and zinc nitrate (CPO-7), respectively. In CPO-6, the tetrahedral zinc atoms are connected by two μ 2 -OH groups and two carboxylate oxygen atoms, forming infinite layers extending parallel to the bc-plane. These layers are pillared by ndc to form a three-dimensional structure. In CPO-7, the zinc hydroxide layers are containing four-, five- and six coordinated zinc atoms, and the layers are built like stairways running along the [001] direction. Each step is composed of three infinite chains running in the [010] direction. Both crystal structures were solved from conventional single crystal data. Crystal data for CPO-6: Monoclinic space group P2 1 /c (No. 14), a=11.9703(7), b=7.8154(5), c=6.2428(4) A, β=90.816(2) deg., V=583.97(6) A 3 and Z=4. Crystal data for CPO-7: Monoclinic space group C2/c (No. 15), a=35.220(4), b=6.2658(8), c=14.8888(17) A, β=112.580(4) deg., V=3033.8(6) A 3 and Z=8. The compounds were further characterized by thermogravimetric- and chemical analysis

  9. Solar storms; Tormentas solares

    Energy Technology Data Exchange (ETDEWEB)

    Collaboration: Pereira Cuesta, S.; Pereira Pagan, B.

    2016-08-01

    Solar storms begin with an explosion, or solar flare, on the surface of the sun. The X-rays and extreme ultraviolet radiation from the flare reach the Earths orbit minutes later-travelling at light speed. The ionization of upper layers of our atmosphere could cause radio blackouts and satellite navigation errors (GPS). Soon after, a wave of energetic particles, electrons and protons accelerated by the explosion crosses the orbit of the Earth, and can cause real and significant damage. (Author)

  10. Strong blue emission from zinc hydroxide carbonate nanosheets

    International Nuclear Information System (INIS)

    Mao, Jing; Chen, Xuemin; Ling, Tao; Du, Xiwen

    2016-01-01

    Zinc hydroxide carbonate (ZHC) is a typical layered salt composed of zinc hydroxide layers separated with carbonate ions and water molecules. Studies of morphology control and the constitution of functional ZHC material with intercalated ions has been widely developed. Also, ZnO can be easily obtained by anneal treatment of ZHC, and the porous structure as synthesized had great potential in gas sensors, photocatalysts and dye-sensitized solar cells. However, the optical of ZHC have rarely been investigated. In our research, a strong blue emission of ZHC is reported. The effect of growth time, annealing treatment and modification of surfactants on blue emission have been systematically studied. Combined with information of interior effect of OH groups, crystal structure and electronegativity of surfactants, a possible emission mechanism of ZHC has been proposed.

  11. Effect of zinc sources on yield and utilization of zinc in rice-wheat sequence

    International Nuclear Information System (INIS)

    Deb, D.L.

    1990-01-01

    A field experiment was conducted on an inceptisol of Delhi to evaluate three sources of zinc, namely, zinc sulphate, zincated urea and zinc oxide on yield and utilization of zinc in rice-wheat sequence. Results indicated that, amongst the three zinc sources, zinc sulphate and zincated urea gave the best performance in increasing the grain yield of rice whereas zinc oxide depressed the grain yield of wheat significantly when compared to other treatments. The highest Zn derived from fertilizer and its utilization was obtained with zinc sulphate for both rice and wheat crops. (author). 9 refs., 4 tabs

  12. Economic viability of thin-film tandem solar modules in the United States

    Science.gov (United States)

    Sofia, Sarah E.; Mailoa, Jonathan P.; Weiss, Dirk N.; Stanbery, Billy J.; Buonassisi, Tonio; Peters, I. Marius

    2018-05-01

    Tandem solar cells are more efficient but more expensive per unit area than established single-junction (SJ) solar cells. To understand when specific tandem architectures should be utilized, we evaluate the cost-effectiveness of different II-VI-based thin-film tandem solar cells and compare them to the SJ subcells. Levelized cost of electricity (LCOE) and energy yield are calculated for four technologies: industrial cadmium telluride and copper indium gallium selenide, and their hypothetical two-terminal (series-connected subcells) and four-terminal (electrically independent subcells) tandems, assuming record SJ quality subcells. Different climatic conditions and scales (residential and utility scale) are considered. We show that, for US residential systems with current balance-of-system costs, the four-terminal tandem has the lowest LCOE because of its superior energy yield, even though it has the highest US per watt (US W-1) module cost. For utility-scale systems, the lowest LCOE architecture is the cadmium telluride single junction, the lowest US W-1 module. The two-terminal tandem requires decreased subcell absorber costs to reach competitiveness over the four-terminal one.

  13. Enhancement of device performance of organic solar cells by an interfacial perylene derivative layer

    KAUST Repository

    Kim, Inho; Haverinen, Hanna M.; Li, Jian; Jabbour, Ghassan E.

    2010-01-01

    We report that device performance of organic solar cells consisting of zinc phthalocyanine and fullerene (C60) can be enhanced by insertion of a perylene derivative interfacial layer between fullerene and bathocuproine (BCP) exciton blocking layer

  14. EDITORIAL Solar harvest Solar harvest

    Science.gov (United States)

    Demming, Anna

    2010-12-01

    into the charge transport mechanism and trap distribution in these composites [3]. An advantage of investigating solar cell technology based on organic materials rather than silicon is that silicon photovoltaics requires high-purity silicon, whereas the material demands of organic technology are not nearly so strict. Work by researchers in Denmark and Germany highlights the simplicity and tolerance to ambient conditions of organic photovoltaic fabrication in the demonstration of a nanostructured polymer solar cell made from a thermocleavable polymer material and zinc oxide nanoparticles. All the manipulations during device preparation could be carried out in air at around 20 °C and 35% humidity [4]. A possible route to enhancing cell performance is through the improvment of the transport efficiency. Researchers in Taiwan demonstrate how effectively this can be implemented in a hybrid device comprising TiO2 nanorods and poly[2-methoxy-5-(2-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) [5]. In addition, inorganic semiconductor nanocrystals that have tunable optical bandgaps can be combined with organic semiconductors for the fabrication of hybrid photovoltaic devices with broad spectral sensitivity. A collaboration of researchers in the UK and the US has now developed a near-infrared sensitive hybrid photovoltaic system with PbS nanocrystals and C60. The reported improvement in device performance is attributed to increased carrier mobility of the PbS nanocrystal film [6]. In this issue, Patrick G Nicholson and Fernando A Castro from the National Physical Laboratory in the UK present a topical review on the principles and techniques for the characterization of organic photovoltaics [7]. The review presents a comprehensive picture of the current state-of-the-art understanding of the working mechanisms behind organic solar cells, and also describes electronic morphological considerations relevant to optimizing the devices, as well as different nanoscale techniques for

  15. Zinc content of selected tissues and taste perception in rats fed zinc deficient and zinc adequate rations

    International Nuclear Information System (INIS)

    Boeckner, L.S.; Kies, C.

    1986-01-01

    The objective of the study was to determine the effects of feeding zinc sufficient and zinc deficient rations on taste sensitivity and zinc contents of selected organs in rats. The 36 Sprague-Dawley male weanling rats were divided into 2 groups and fed zinc deficient or zinc adequate rations. The animals were subjected to 4 trial periods in which a choice of deionized distilled water or a solution of quinine sulfate at 1.28 x 10 -6 was given. A randomized schedule for rat sacrifice was used. No differences were found between zinc deficient and zinc adequate rats in taste preference aversion scores for quinine sulfate in the first three trial periods; however, in the last trial period rats in the zinc sufficient group drank somewhat less water containing quinine sulfate as a percentage of total water consumption than did rats fed the zinc deficient ration. Significantly higher zinc contents of kidney, brain and parotid salivary glands were seen in zinc adequate rats compared to zinc deficient rats at the end of the study. However, liver and tongue zinc levels were lower for both groups at the close of the study than were those of rats sacrificed at the beginning of the study

  16. Crystalline perfection and mechanical investigations on vertical Bridgman grown Bismuth telluride (Bi{sub 2}Te{sub 3}) single crystals for thermoelectric applications

    Energy Technology Data Exchange (ETDEWEB)

    Krishna, Anuj [Academy of Scientific and Innovative Research, CSIR- National Physical Laboratory, New Delhi 110012 (India); X-ray Analysis and Crystal Growth Section, CSIR-National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012 (India); Vijayan, N., E-mail: nvijayan@nplindia.org [X-ray Analysis and Crystal Growth Section, CSIR-National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012 (India); Singh, Budhendra [TEMA-NRD, Mechanical Engineering Department and Aveiro Institute of Nanotechnology (AIN), University of Aveiro, 3810-193 Aveiro (Portugal); Thukral, Kanika [Academy of Scientific and Innovative Research, CSIR- National Physical Laboratory, New Delhi 110012 (India); X-ray Analysis and Crystal Growth Section, CSIR-National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012 (India); Maurya, K.K. [X-ray Analysis and Crystal Growth Section, CSIR-National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012 (India)

    2016-03-07

    High efficiency thermoelectric materials plays a vital role in power generation and refrigeration applications. Bismuth telluride (Bi{sub 2}Te{sub 3}) is one among them. In the present work single crystal of bismuth telluride was grown using vertical Bridgman technique. The phase of grown crystals was analysed using a powder X-ray diffractometer. Quality of the grown crystal was assessed by using high resolution X-ray diffractometer and observed that it is fairly good. Further mechanical investigations on grown crystal was carried out using nano-indentation technique and various mechanical properties like hardness, stiffness and Young’s modulus were evaluated. Observed results clearly indicate its suitability for thermoelectric applications.

  17. The study and microstructure analysis of zinc and zinc oxide

    Directory of Open Access Journals (Sweden)

    N. Luptáková

    2015-01-01

    Full Text Available The given paper is closely connected with the process of the manufacturing of ZnO. The purity of the metal zinc has crucial influence on the quality of ZnO. ZnO can be produced by pyrometallurgical combustion of zinc and hard zinc. But this mentioned method of preparation leads to the creation of the enormous amount of waste including chemical complexes. On the basis of the occurrence of the residual content of other elements, it is possible to make prediction about the material behavior in the metallographic process. The input and finally materials were investigated and this investigation was done from the aspect of structural and chemical composition of the materials.

  18. Vapor transport deposition of antimony selenide thin film solar cells with 7.6% efficiency.

    Science.gov (United States)

    Wen, Xixing; Chen, Chao; Lu, Shuaicheng; Li, Kanghua; Kondrotas, Rokas; Zhao, Yang; Chen, Wenhao; Gao, Liang; Wang, Chong; Zhang, Jun; Niu, Guangda; Tang, Jiang

    2018-06-05

    Antimony selenide is an emerging promising thin film photovoltaic material thanks to its binary composition, suitable bandgap, high absorption coefficient, inert grain boundaries and earth-abundant constituents. However, current devices produced from rapid thermal evaporation strategy suffer from low-quality film and unsatisfactory performance. Herein, we develop a vapor transport deposition technique to fabricate antimony selenide films, a technique that enables continuous and low-cost manufacturing of cadmium telluride solar cells. We improve the crystallinity of antimony selenide films and then successfully produce superstrate cadmium sulfide/antimony selenide solar cells with a certified power conversion efficiency of 7.6%, a net 2% improvement over previous 5.6% record of the same device configuration. We analyze the deep defects in antimony selenide solar cells, and find that the density of the dominant deep defects is reduced by one order of magnitude using vapor transport deposition process.

  19. Ag-tellurides at the site Treibolc near the village Hodrusa-Hamre; Ag-teluridy na lokalite Treibolc pri obci Hodrusa-Hamre

    Energy Technology Data Exchange (ETDEWEB)

    Kozak, J [Univerzita Komenskeho v Bratislave, Prirodovedecka fakulta, Katedra mineralogie a petrologie, 84215 Bratislava (Slovakia)

    2012-04-25

    Ag-tellurides were described in association with galenite, sphalerite, chalcopyrite and bornite samples during examining hydrothermal mineralization of Stiavnica stratovolcano (Hodrusa-Hamre settlement) in heavily silicified sediments of Permian age. They were found and confirmed by WDS analysis. Their presence on the site is very unique with no economic use. Paragenesis originated at 250-270 grad C in the presence of fluid and zero salinity. (authors)

  20. Solar Energy.

    Science.gov (United States)

    Eaton, William W.

    Presented is the utilization of solar radiation as an energy resource principally for the production of electricity. Included are discussions of solar thermal conversion, photovoltic conversion, wind energy, and energy from ocean temperature differences. Future solar energy plans, the role of solar energy in plant and fossil fuel production, and…

  1. Influence of DNA-methylation on zinc homeostasis in myeloid cells: Regulation of zinc transporters and zinc binding proteins.

    Science.gov (United States)

    Kessels, Jana Elena; Wessels, Inga; Haase, Hajo; Rink, Lothar; Uciechowski, Peter

    2016-09-01

    The distribution of intracellular zinc, predominantly regulated through zinc transporters and zinc binding proteins, is required to support an efficient immune response. Epigenetic mechanisms such as DNA methylation are involved in the expression of these genes. In demethylation experiments using 5-Aza-2'-deoxycytidine (AZA) increased intracellular (after 24 and 48h) and total cellular zinc levels (after 48h) were observed in the myeloid cell line HL-60. To uncover the mechanisms that cause the disturbed zinc homeostasis after DNA demethylation, the expression of human zinc transporters and zinc binding proteins were investigated. Real time PCR analyses of 14 ZIP (solute-linked carrier (SLC) SLC39A; Zrt/IRT-like protein), and 9 ZnT (SLC30A) zinc transporters revealed significantly enhanced mRNA expression of the zinc importer ZIP1 after AZA treatment. Because ZIP1 protein was also enhanced after AZA treatment, ZIP1 up-regulation might be the mediator of enhanced intracellular zinc levels. The mRNA expression of ZIP14 was decreased, whereas zinc exporter ZnT3 mRNA was also significantly increased; which might be a cellular reaction to compensate elevated zinc levels. An enhanced but not significant chromatin accessibility of ZIP1 promoter region I was detected by chromatin accessibility by real-time PCR (CHART) assays after demethylation. Additionally, DNA demethylation resulted in increased mRNA accumulation of zinc binding proteins metallothionein (MT) and S100A8/S100A9 after 48h. MT mRNA was significantly enhanced after 24h of AZA treatment also suggesting a reaction of the cell to restore zinc homeostasis. These data indicate that DNA methylation is an important epigenetic mechanism affecting zinc binding proteins and transporters, and, therefore, regulating zinc homeostasis in myeloid cells. Copyright © 2016 Elsevier GmbH. All rights reserved.

  2. Solar energy

    Science.gov (United States)

    Rapp, D.

    1981-01-01

    The book opens with a review of the patterns of energy use and resources in the United States, and an exploration of the potential of solar energy to supply some of this energy in the future. This is followed by background material on solar geometry, solar intensities, flat plate collectors, and economics. Detailed attention is then given to a variety of solar units and systems, including domestic hot water systems, space heating systems, solar-assisted heat pumps, intermediate temperature collectors, space heating/cooling systems, concentrating collectors for high temperatures, storage systems, and solar total energy systems. Finally, rights to solar access are discussed.

  3. Solar Combisystems

    DEFF Research Database (Denmark)

    Thür, Alexander

    2006-01-01

    This note first introduces what is a solar combisystem, the structure how a solar combisystem is build up and what are criteria’s to evaluate a solar combisystem concept. Further on the main components of a solar combisystem, the main characteristics and possible advantages and disadvantages...... compared to each other are described. It is not the goal of this note to explain the technical details how to design all components of a solar combisystem. This is done during other lectures of the solar course and in other basic courses as well. This note tries to explain how a solar combisystem...

  4. Solar Systems

    Science.gov (United States)

    1979-01-01

    The solar collectors shown are elements of domestic solar hot water systems produced by Solar One Ltd., Virginia Beach, Virginia. Design of these systems benefited from technical expertise provided Solar One by NASA's Langley Research Center. The company obtained a NASA technical support package describing the d e sign and operation of solar heating equipment in NASA's Tech House, a demonstration project in which aerospace and commercial building technology are combined in an energy- efficient home. Solar One received further assistance through personal contact with Langley solar experts. The company reports that the technical information provided by NASA influenced Solar One's panel design, its selection of a long-life panel coating which increases solar collection efficiency, and the method adopted for protecting solar collectors from freezing conditions.

  5. Impact of residual elements on zinc quality in the production of zinc oxide

    Czech Academy of Sciences Publication Activity Database

    Luptáková, Natália; Dymáček, Petr; Pešlová, F.; Jurkovič, Z.; Barborák, O.; Stodola, J.

    2016-01-01

    Roč. 55, č. 3 (2016), s. 407-410 ISSN 0543-5846 Institutional support: RVO:68081723 Keywords : zinc * metallography * microstructure of zinc * zinc oxide * production of zinc oxide Subject RIV: JG - Metallurgy Impact factor: 0.959, year: 2014

  6. Zinc Biochemistry: From a Single Zinc Enzyme to a Key Element of Life12

    Science.gov (United States)

    Maret, Wolfgang

    2013-01-01

    The nutritional essentiality of zinc for the growth of living organisms had been recognized long before zinc biochemistry began with the discovery of zinc in carbonic anhydrase in 1939. Painstaking analytical work then demonstrated the presence of zinc as a catalytic and structural cofactor in a few hundred enzymes. In the 1980s, the field again gained momentum with the new principle of “zinc finger” proteins, in which zinc has structural functions in domains that interact with other biomolecules. Advances in structural biology and a rapid increase in the availability of gene/protein databases now made it possible to predict zinc-binding sites from metal-binding motifs detected in sequences. This procedure resulted in the definition of zinc proteomes and the remarkable estimate that the human genome encodes ∼3000 zinc proteins. More recent developments focus on the regulatory functions of zinc(II) ions in intra- and intercellular information transfer and have tantalizing implications for yet additional functions of zinc in signal transduction and cellular control. At least three dozen proteins homeostatically control the vesicular storage and subcellular distribution of zinc and the concentrations of zinc(II) ions. Novel principles emerge from quantitative investigations on how strongly zinc interacts with proteins and how it is buffered to control the remarkably low cellular and subcellular concentrations of free zinc(II) ions. It is fair to conclude that the impact of zinc for health and disease will be at least as far-reaching as that of iron. PMID:23319127

  7. Outdoor fate and environmental impact of polymer solar cells through leaching and emission to rainwater and soil

    NARCIS (Netherlands)

    Espinosa, Nieves; Zimmermann, Yannick-Serge; Reis Benatto, Dos Gisele A.; Lenz, Markus; Krebs, Frederik C.

    2016-01-01

    The emission of silver and zinc to the aqueous environment (rain, fog, dew) from polymer solar cells installed outdoors is presented. Studies included pristine solar cells and solar cells subjected to mechanical damage under natural weather conditions in Denmark. We find the emission of silver and

  8. Outdoor fate and environmental impact of polymer solar cells through leaching and emission to rainwater and soil

    DEFF Research Database (Denmark)

    Espinosa Martinez, Nieves; Zimmermann, Yannick-Serge; Benatto, Gisele Alves dos Reis

    2016-01-01

    The emission of silver and zinc to the aqueous environment (rain, fog, dew) from polymer solar cells installed outdoors is presented. Studies included pristine solar cells and solar cells subjected to mechanical damage under natural weather conditions in Denmark. We find the emission of silver...

  9. Solar radiophysics

    International Nuclear Information System (INIS)

    McLean, D.J.; Labrum, N.R.

    1985-01-01

    This book treats all aspects of solar radioastronomy at metre wavelengths, particularly work carried out on the Australian radioheliograph at Culgoora, with which most of the authors have been associated in one way or another. After an introductory section on historical aspects, the solar atmosphere, solar flares, and coronal radio emission, the book deals with instrumentation, theory, and details of observations and interpretations of the various aspects of metrewave solar radioastronomy, including burst types, solar storms, and the quiet sun. (U.K.)

  10. Zinc: a multipurpose trace element

    Energy Technology Data Exchange (ETDEWEB)

    Stefanidou, M.; Maravelias, C.; Dona, A.; Spiliopoulou, C. [University of Athens, Department of Forensic Medicine and Toxicology, Athens (Greece)

    2006-01-01

    Zinc (Zn) is one of the most important trace elements in the body and it is essential as a catalytic, structural and regulatory ion. It is involved in homeostasis, in immune responses, in oxidative stress, in apoptosis and in ageing. Zinc-binding proteins (metallothioneins, MTs), are protective in situations of stress and in situations of exposure to toxic metals, infections and low Zn nutrition. Metallothioneins play a key role in Zn-related cell homeostasis due to their high affinity for Zn, which is in turn relevant against oxidative stress and immune responses, including natural killer (NK) cell activity and ageing, since NK activity and Zn ion bioavailability decrease in ageing. Physiological supplementation of Zn in ageing and in age-related degenerative diseases corrects immune defects, reduces infection relapse and prevents ageing. Zinc is not stored in the body and excess intakes result in reduced absorption and increased excretion. Nevertheless, there are cases of acute and chronic Zn poisoning. (orig.)

  11. [Improvement in zinc nutrition due to zinc transporter-targeting strategy].

    Science.gov (United States)

    Kambe, Taiho

    2016-07-01

    Adequate intake of zinc from the daily diet is indispensable to maintain health. However, the dietary zinc content often fails to fulfill the recommended daily intake, leading to zinc deficiency and also increases the risk of developing chronic diseases, particularly in elderly individuals. Therefore, increased attention is required to overcome zinc deficiency and it is important to improve zinc nutrition in daily life. In the small intestine, the zinc transporter, ZIP4, functions as a component that is essential for zinc absorption. In this manuscript, we present a brief overview regarding zinc deficiency. Moreover, we review a novel strategy, called "ZIP4-targeting", which has the potential to enable efficient zinc absorption from the diet. ZIP4-targeting strategy is possibly a major step in preventing zinc deficiency and improving human health.

  12. Zinc blotting assay for detection of zinc binding prolamin in barley (Hordeum vulgare) grain

    DEFF Research Database (Denmark)

    Uddin, Mohammad Nasir; Nielsen, Ane Langkilde-Lauesen; Vincze, Eva

    2014-01-01

    In plants, zinc is commonly found bound to proteins. In barley (Hordeum vulgare), major storage proteins are alcohol-soluble prolamins known as hordeins, and some of them have the potential to bind or store zinc. 65Zn overlay and blotting techniques have been widely used for detecting zinc......-binding protein. However, to our knowledge so far this zinc blotting assay has never been applied to detect a prolamin fraction in barley grains. A radioactive zinc (65ZnCl2) blotting technique was optimized to detect zinc-binding prolamins, followed by development of an easy-to-follow nonradioactive colorimetric...... zinc blotting method with a zinc-sensing dye, dithizone. Hordeins were extracted from mature barley grain, separated by SDS-PAGE, blotted on a membrane, renatured, overlaid, and probed with zinc; subsequently, zinc-binding specificity of certain proteins was detected either by autoradiography or color...

  13. 21 CFR 582.5985 - Zinc chloride.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Zinc chloride. 582.5985 Section 582.5985 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5985 Zinc chloride. (a) Product. Zinc chloride. (b) Conditions of use. This substance is...

  14. 21 CFR 182.8985 - Zinc chloride.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Zinc chloride. 182.8985 Section 182.8985 Food and... CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8985 Zinc chloride. (a) Product. Zinc chloride. (b) Conditions of use. This substance is generally recognized as safe when used in...

  15. 21 CFR 558.78 - Bacitracin zinc.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Bacitracin zinc. 558.78 Section 558.78 Food and... in Animal Feeds § 558.78 Bacitracin zinc. (a) Specifications. Type A medicated articles containing bacitracin zinc equivalent to 10, 25, 40, or 50 grams per pound bacitracin. (b) Approvals. See No. 046573 in...

  16. relationship between maternal serum zinc, cord blood zinc and birth

    African Journals Online (AJOL)

    FOBUR

    those obtained by Okonofua et al in Ile-Ife and. 17. Iqbal et al in Bangladesh but lower than the values. 18. 11 reported in studies in India and the United States. The similarity in the mean maternal serum zinc obtained in this study with the studies in Ife and. Bangladesh could be a reflection of the similarity among the study ...

  17. Rational Design of Zinc Phosphide Heterojunction Photovoltaics

    Science.gov (United States)

    Bosco, Jeffrey Paul

    The prospect of terawatt-scale electricity generation using a photovoltaic (PV) device places strict requirements on the active semiconductor optoelectronic properties and elemental abundance. After reviewing the constraints placed on an ``earth-abundant'' solar absorber, we find zinc phosphide (α-Zn 3P2) to be an ideal candidate. In addition to its near-optimal direct band gap of 1.5 eV, high visible-light absorption coefficient (>10. 4cm-1), and long minority-carrier diffusion length (>5 μm), Zn3P 2 is composed of abundant Zn and P elements and has excellent physical properties for scalable thin-film deposition. However, to date, a Zn 3P2 device of sufficient efficiency for commercial applications has not been demonstrated. Record efficiencies of 6.0% for multicrystalline and 4.3% for thin-film cells have been reported, respectively. Performance has been limited by the intrinsic p-type conductivity of Zn3P 2 which restricts us to Schottky and heterojunction device designs. Due to our poor understanding of Zn3P2 interfaces, an ideal heterojunction partner has not yet been found. The goal of this thesis is to explore the upper limit of solar conversion efficiency achievable with a Zn3P2 absorber through the design of an optimal heterojunction PV device. To do so, we investigate three key aspects of material growth, interface energetics, and device design. First, the growth of Zn3P2 on GaAs(001) is studied using compound-source molecular-beam epitaxy (MBE). We successfully demonstrate the pseudomorphic growth of Zn3P2 epilayers of controlled orientation and optoelectronic properties. Next, the energy-band alignments of epitaxial Zn3P2 and II-VI and III-V semiconductor interfaces are measured via high-resolution x-ray photoelectron spectroscopy in order to determine the most appropriate heterojunction partner. From this work, we identify ZnSe as a nearly ideal n-type emitter for a Zn3P 2 PV device. Finally, various II-VI/Zn3P2 heterojunction solar cells designs are

  18. Effect of resveratrol and zinc on intracellular zinc status in normal human prostate epithelial cells

    Science.gov (United States)

    To evaluate the influence of resveratrol on cellular zinc status, normal human prostate epithelial (NHPrE) cells were treated with 6 levels of resveratrol (0, 0.5, 1, 2.5, 5 and 10 microM) and 4 levels of zinc [0, 4, 16, and 32 microM for zinc-deficient (ZD), zinc-normal (ZN), zinc-adequate (ZA), an...

  19. Helios: Understanding Solar Evolution Through Text Analytics

    Energy Technology Data Exchange (ETDEWEB)

    Randazzese, Lucien [SRI International, Menlo Park, CA (United States)

    2016-12-02

    This proof-of-concept project focused on developing, testing, and validating a range of bibliometric, text analytic, and machine-learning based methods to explore the evolution of three photovoltaic (PV) technologies: Cadmium Telluride (CdTe), Dye-Sensitized solar cells (DSSC), and Multi-junction solar cells. The analytical approach to the work was inspired by previous work by the same team to measure and predict the scientific prominence of terms and entities within specific research domains. The goal was to create tools that could assist domain-knowledgeable analysts in investigating the history and path of technological developments in general, with a focus on analyzing step-function changes in performance, or “breakthroughs,” in particular. The text-analytics platform developed during this project was dubbed Helios. The project relied on computational methods for analyzing large corpora of technical documents. For this project we ingested technical documents from the following sources into Helios: Thomson Scientific Web of Science (papers), the U.S. Patent & Trademark Office (patents), the U.S. Department of Energy (technical documents), the U.S. National Science Foundation (project funding summaries), and a hand curated set of full-text documents from Thomson Scientific and other sources.

  20. Cyclic AMP Pathway Activation and Extracellular Zinc Induce Rapid Intracellular Zinc Mobilization in Candida albicans

    Science.gov (United States)

    Kjellerup, Lasse; Winther, Anne-Marie L.; Wilson, Duncan; Fuglsang, Anja T.

    2018-01-01

    Zinc is an essential micronutrient, required for a range of zinc-dependent enzymes and transcription factors. In mammalian cells, zinc serves as a second messenger molecule. However, a role for zinc in signaling has not yet been established in the fungal kingdom. Here, we used the intracellular zinc reporter, zinbo-5, which allowed visualization of zinc in the endoplasmic reticulum and other components of the internal membrane system in Candida albicans. We provide evidence for a link between cyclic AMP/PKA- and zinc-signaling in this major human fungal pathogen. Glucose stimulation, which triggers a cyclic AMP spike in this fungus resulted in rapid intracellular zinc mobilization and this “zinc flux” could be stimulated with phosphodiesterase inhibitors and blocked via inhibition of adenylate cyclase or PKA. A similar mobilization of intracellular zinc was generated by stimulation of cells with extracellular zinc and this effect could be reversed with the chelator EDTA. However, zinc-induced zinc flux was found to be cyclic AMP independent. In summary, we show that activation of the cyclic AMP/PKA pathway triggers intracellular zinc mobilization in a fungus. To our knowledge, this is the first described link between cyclic AMP signaling and zinc homeostasis in a human fungal pathogen. PMID:29619016

  1. Landfill waste and recycling: Use of a screening-level risk assessment tool for end-of-life cadmium telluride (CdTe) thin-film photovoltaic (PV) panels

    International Nuclear Information System (INIS)

    Cyrs, William D.; Avens, Heather J.; Capshaw, Zachary A.; Kingsbury, Robert A.; Sahmel, Jennifer; Tvermoes, Brooke E.

    2014-01-01

    Grid-connected solar photovoltaic (PV) power is currently one of the fastest growing power-generation technologies in the world. While PV technologies provide the environmental benefit of zero emissions during use, the use of heavy metals in thin-film PV cells raises important health and environmental concerns regarding the end-of-life disposal of PV panels. To date, there is no published quantitative assessment of the potential human health risk due to cadmium leaching from cadmium telluride (CdTe) PV panels disposed in a landfill. Thus, we used a screening-level risk assessment tool to estimate possible human health risk associated with disposal of CdTe panels into landfills. In addition, we conducted a literature review of potential cadmium release from the recycling process in order to contrast the potential health risks from PV panel disposal in landfills to those from PV panel recycling. Based on the results of our literature review, a meaningful risk comparison cannot be performed at this time. Based on the human health risk estimates generated for PV panel disposal, our assessment indicated that landfill disposal of CdTe panels does not pose a human health hazard at current production volumes, although our results pointed to the importance of CdTe PV panel end-of-life management. - Highlights: • Analysis of possible human health risk posed by disposal of CdTe panels into landfills. • Qualitative comparison of risks associated with landfill disposal and recycling of CdTe panels. • Landfill disposal of CdTe panels does not pose a human health hazard at current production volumes. • There could be potential risks associated with recycling if not properly managed. • Factors other than concerns over toxic substances will likely drive the decisions of how to manage end-of-life PV panels

  2. Copper, lead and zinc production

    International Nuclear Information System (INIS)

    Ayers, J.; Ternan, S.

    2001-01-01

    This chapter provides information on the by-products and residues generated during the production of copper, lead and zinc. The purpose of this chapter is to describe by-products and residues which are generated, how these may be avoided or minimised, and available options for the utilization and management of residues. (author)

  3. Serum zinc level in thalassemia

    International Nuclear Information System (INIS)

    Keikhaei, B.; Badavi, M.; Pedram, M.; Zandian, K.

    2010-01-01

    To compare serum zinc level between Thalassemia Major (TM) patients and normal population at Shafa Hospital in South West of Iran. A total of 25 male and 36 female of TM patients were enrolled in this study. Out of 61 patients thirty were treated by deferroxamine (DFO) and 31 were on the combination of DFO and deferiprone (DEF) protocol therapy. Sixty normal subjects of the matching age and gender were recruited as controls. From each patient and control group 2 ml of blood was taken in fasting condition. Cell blood count and serum zinc were carried out for both thalassemia patients and normal subjects. The mean age of patients and control group was 15+- 5 years. Mean serum zinc level was 68.97+- 21.12 mu g/dl, 78.10-28.50 mu g/dl, and 80.16+- 26.54 mu g/dl in the TM with DFO, TM with DFO + DEF combination protocol and control group respectively. There was no significant correlation between patients and control group. However 50 percent of TM with DFO, 38.7 percent of TM with DFO + DEF and 32.8 percent of control group had hypozincemia. Nearly 40 to 50 percent of TM patients and one third of normal subjects are suffering from hypozincemia. This study shows that low level of serum zinc is a health problem in both thalassemia patients and normal population in South West of Iran. (author)

  4. Molybdate based passivation of zinc

    DEFF Research Database (Denmark)

    Tang, Peter Torben; Bech-Nielsen, Gregers; Møller, Per

    1997-01-01

    In order to reduce corrosion rates, zinc plated parts are usually chromated. Recently chromates have caused increasingly environmental concern, for both allergic effects among workers touching chro-mated parts and toxic effects on fish, plants and bacteria. A molybdate based alternative has been...

  5. Modelling of illuminated current–voltage characteristics to evaluate leakage currents in long wavelength infrared mercury cadmium telluride photovoltaic detectors

    International Nuclear Information System (INIS)

    Gopal, Vishnu; Qiu, WeiCheng; Hu, Weida

    2014-01-01

    The current–voltage characteristics of long wavelength mercury cadmium telluride infrared detectors have been studied using a recently suggested method for modelling of illuminated photovoltaic detectors. Diodes fabricated on in-house grown arsenic and vacancy doped epitaxial layers were evaluated for their leakage currents. The thermal diffusion, generation–recombination (g-r), and ohmic currents were found as principal components of diode current besides a component of photocurrent due to illumination. In addition, both types of diodes exhibited an excess current component whose growth with the applied bias voltage did not match the expected growth of trap-assisted-tunnelling current. Instead, it was found to be the best described by an exponential function of the type, I excess  = I r0  + K 1 exp (K 2 V), where I r0 , K 1 , and K 2 are fitting parameters and V is the applied bias voltage. A study of the temperature dependence of the diode current components and the excess current provided the useful clues about the source of origin of excess current. It was found that the excess current in diodes fabricated on arsenic doped epitaxial layers has its origin in the source of ohmic shunt currents. Whereas, the source of excess current in diodes fabricated on vacancy doped epitaxial layers appeared to be the avalanche multiplication of photocurrent. The difference in the behaviour of two types of diodes has been attributed to the difference in the quality of epitaxial layers

  6. A simple fast microwave-assisted synthesis of thermoelectric bismuth telluride nanoparticles from homogeneous reaction-mixture

    Energy Technology Data Exchange (ETDEWEB)

    Pradhan, Susmita [Jadavpur University, Department of Instrumentation Science (India); Das, Rashmita [Jadavpur University, Department of Instrumentation and Electronics Engineering (India); Bhar, Radhaballabh [Jadavpur University, Department of Instrumentation Science (India); Bandyopadhyay, Rajib [Jadavpur University, Department of Instrumentation and Electronics Engineering (India); Pramanik, Panchanan, E-mail: pramanik1946@gmail.com [GLA University, Department of Chemistry and Nanoscience (India)

    2017-02-15

    A new simple chemical method for synthesis of nanocrystalline bismuth telluride (Bi{sub 2}Te{sub 3}) has been developed by microwave assisted reduction of homogeneous tartrate complexes of bismuth and tellurium metal ions with hydrazine. The reaction is performed at pH 10. The nano-crystallites have rhombohedral phase identified by XRD. The size distribution of nanoparticle is narrow and it ranges between 50 to 70 nm. FESEM shows that the fine powders are composed of small crystallites. The TEM micrographs show mostly deformed spherical particles and the lattice fringes are found to be 0.137 nm. Energy dispersive X-ray spectroscopy (EDX) analysis shows the atomic composition ratio between bismuth and tellurium is 2:3. Thermoelectric properties of the materials are studied after sintering by spark plasma sintering method (SPS). The grain size of the material after sintering is in the nanometer range. The material shows enhanced Seebeck coefficient and electrical conductivity value at 300 K. The figure of merit is found to be 1.18 at 300 K.

  7. CsAg{sub 5}Te{sub 3}: a new metal-rich telluride with a unique tunnel structure

    Energy Technology Data Exchange (ETDEWEB)

    Jing, Li [Rutgers Univ., Camden, NJ (United States). Dept. of Chem.; Hongyou, Guo [Rutgers Univ., Camden, NJ (United States). Dept. of Chem.; Xiang, Zhang [Michigan State Univ., East Lansing, MI (United States). Dept. of Chemistry; Kanatzidis, M G [Michigan State Univ., East Lansing, MI (United States). Dept. of Chemistry

    1995-02-15

    The synthesis and structure of a new ternary silver telluride, CsAg{sub 5}Te{sub 3}, is described. The compound was prepared from a Cs{sub 2}Te-CaTe-Te flux but it can also be prepared from a direct combination of Cs{sub 2}Te and Ag{sub 2}Te under vacuum at 600 C. The crystal data for CsAg{sub 5}Te{sub 3} at 20 C (Mo K{alpha} radiation) are as follows: a=14.672(2) A and c=4.601(3) A; V=990.5(8) A{sup 3}; Z=4; D{sub calc}=7.075 g cm{sup -3}; space group, P4{sub 2} /mnm (No. 136); 2{theta}{sub max}=50 ; number of independent data collected, 572; number of data observed with I>3{sigma}(I), 267; number of variables, 32; {mu}=218.51 cm{sup -1}; extinction coefficient, 0.585x10{sup -7}; final R=0.040; R{sub w}=0.046; goodness of fit, 1.42. The compound features a new structure type with Cs{sup +}-filled, relatively large tunnels running through the lattice. The material is a semiconductor with a band gap of about 0.65 eV. ((orig.))

  8. Synthesis, characterization and enhanced thermoelectric performance of structurally ordered cable-like novel polyaniline–bismuth telluride nanocomposite

    International Nuclear Information System (INIS)

    Chatterjee, Krishanu; Mitra, Mousumi; Banerjee, Dipali; Kargupta, Kajari; Ganguly, Saibal

    2013-01-01

    Bismuth telluride (Bi 2 Te 3 ) nanorods and polyaniline (PANI) nanoparticles have been synthesized by employing solvothermal and chemical oxidative processes, respectively. Nanocomposites, comprising structurally ordered PANI preferentially grown along the surface of a Bi 2 Te 3 nanorods template, are synthesized using in situ polymerization. X-ray powder diffraction, UV–vis and Raman spectral analysis confirm the highly ordered chain structure of PANI on Bi 2 Te 3 nanorods, leading to a higher extent of doping, higher chain mobility and enhancement of the thermoelectric performance. Above 380 K, the PANI–Bi 2 Te 3 nanocomposite with a core–shell/cable-like structure exhibits a higher thermoelectric power factor than either pure PANI or Bi 2 Te 3 . At room temperature the thermal conductivity of the composite is lower than that of its pure constituents, due to selective phonon scattering by the nanointerfaces designed in the PANI–Bi 2 Te 3 nanocable structures. The figure of merit of the nanocomposite at room temperature is comparable to the values reported in the literature for bulk polymer-based composite thermoelectric materials. (paper)

  9. Bismuth telluride topological insulator nanosheet saturable absorbers for q-switched mode-locked Tm:ZBLAN waveguide lasers

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Xiantao; Gross, Simon; Withford, Michael J.; Fuerbach, Alexander [Centre for Ultrahigh bandwidth Devices for Optical Systems (CUDOS) and MQ Photonics Research Centre, Dept. of Physics and Astronomy, Macquarie Univ., NSW (Australia); Zhang, Han; Guo, Zhinan [SZU-NUS Collaborative Innovation Centre for Optoelectronic Science and Technology, Key Lab. of Optoelectronic Devices and Systems of Ministry of Education, College of Optoelectronic Engineering, Shenzhen Univ. (China)

    2016-08-15

    Nanosheets of bismuth telluride (Bi{sub 2}Te{sub 3}), a topological insulator material that exhibits broadband saturable absorption due to its non-trivial Dirac-cone like energy structure, are utilized to generate short pulses from Tm:ZBLAN waveguide lasers. By depositing multiple layers of a carefully prepared Bi{sub 2}Te{sub 3} solution onto a glass substrate, the modulation depth and the saturation intensity of the fabricated devices can be controlled and optimized. This approach enables the realization of saturable absorbers that feature a modulation depth of 13% and a saturation intensity of 997 kW/cm{sup 2}. For the first time to our knowledge, Q-switched mode-locked operation of a linearly polarized mid-IR ZBLAN waveguide chip laser was realized in an extended cavity configuration using the topological insulator Bi{sub 2}Te{sub 3}. The maximum average output power of the laser is 16.3 mW and the Q-switched and mode-locked repetition rates are 44 kHz and 436 MHz, respectively. (copyright 2016 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Regulatory policy governing cadmium-telluride photovoltaics: A case study contrasting life cycle management with the precautionary principle

    International Nuclear Information System (INIS)

    Sinha, Parikhit; Kriegner, Christopher J.; Schew, William A.; Kaczmar, Swiatoslav W.; Traister, Matthew; Wilson, David J.

    2008-01-01

    Market projections for cadmium-telluride (CdTe) thin-film photovoltaics (PV) are tempered by global environmental policies based on the precautionary principle which restrict electronic products containing cadmium, a known human carcinogen. An alternative to the precautionary principle is life cycle management, which involves manufacturers assuming product stewardship from beginning to end of product life. Both approaches have the aim of minimizing environmental contamination, but attempt to do so in different ways. Restrictions on electronic products containing cadmium by the precautionary principle-based restriction of hazardous substances (RoHS) directive in the European Union and a similar policy in China are presented, relative to their potential impact on CdTe PV. Life cycle environmental risks with respect to potential release of cadmium to the environment are also presented for routine operation of CdTe PV panels, potential catastrophic release of cadmium from a residential fire, and at the end of the product life. There is negligible risk of environmental cadmium contamination during routine operation and insignificant risk during catastrophic exposure events such as fire. At the end of the product life, risks of contamination are minimized by take-back programs that may be paid for by insurance premiums incorporated into the cost of the product. Therefore, policies based on the precautionary principle that could potentially ban the product based on its cadmium content may not be warranted

  11. Regulatory policy governing cadmium-telluride photovoltaics: A case study contrasting life cycle management with the precautionary principle

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, Parikhit; Kriegner, Christopher J.; Schew, William A.; Kaczmar, Swiatoslav W.; Traister, Matthew; Wilson, David J. [O' Brien and Gere, Ecological Sciences, E. 512 Township Line Road, Two Valley Square, Suite 120, Blue Bell, PA 19422 (United States)

    2008-01-15

    Market projections for cadmium-telluride (CdTe) thin-film photovoltaics (PV) are tempered by global environmental policies based on the precautionary principle which restrict electronic products containing cadmium, a known human carcinogen. An alternative to the precautionary principle is life cycle management, which involves manufacturers assuming product stewardship from beginning to end of product life. Both approaches have the aim of minimizing environmental contamination, but attempt to do so in different ways. Restrictions on electronic products containing cadmium by the precautionary principle-based restriction of hazardous substances (RoHS) directive in the European Union and a similar policy in China are presented, relative to their potential impact on CdTe PV. Life cycle environmental risks with respect to potential release of cadmium to the environment are also presented for routine operation of CdTe PV panels, potential catastrophic release of cadmium from a residential fire, and at the end of the product life. There is negligible risk of environmental cadmium contamination during routine operation and insignificant risk during catastrophic exposure events such as fire. At the end of the product life, risks of contamination are minimized by take-back programs that may be paid for by insurance premiums incorporated into the cost of the product. Therefore, policies based on the precautionary principle that could potentially ban the product based on its cadmium content may not be warranted. (author)

  12. Derived reference doses for three compounds used in the photovoltaics industry: Copper indium diselenide, copper gallium diselenide, and cadmium telluride

    Energy Technology Data Exchange (ETDEWEB)

    Moskowitz, P.D.; Bernholc, N.; DePhillips, M.P.; Viren, J.

    1995-07-06

    Polycrystalline thin-film photovoltaic modules made from copper indium diselenide (CIS), copper gallium diselenide (CGS), and cadmium telluride (CdTe) arc nearing commercial development. A wide range of issues are being examined as these materials move from the laboratory to large-scale production facilities to ensure their commercial success. Issues of traditional interest include module efficiency, stability and cost. More recently, there is increased focus given to environmental, health and safety issues surrounding the commercialization of these same devices. An examination of the toxicological properties of these materials, and their chemical parents is fundamental to this discussion. Chemicals that can present large hazards to human health or the environment are regulated often more strictly than those that are less hazardous. Stricter control over how these materials are handled and disposed can increase the costs associated with the production and use of these modules dramatically. Similarly, public perception can be strongly influenced by the inherent biological hazard that these materials possess. Thus, this report: presents a brief background tutorial on how toxicological data are developed and used; overviews the toxicological data available for CIS, CGS and CdTe; develops ``reference doses`` for each of these compounds; compares the reference doses for these compounds with those of their parents; discusses the implications of these findings to photovoltaics industry.

  13. Improved colorimetric determination of serum zinc.

    Science.gov (United States)

    Johnson, D J; Djuh, Y Y; Bruton, J; Williams, H L

    1977-07-01

    We show how zinc may easily be quantified in serum by first using an optimum concentration of guanidine hydrochloride to cause release of zinc from proteins, followed by complexation of released metals with cyanide. The cyanide complex of zinc is preferentially demasked with chloral hydrate, followed by a colorimetric reaction between zinc and 4-(2-pyridylazo)resorcinol. This is a sensitive water-soluble ligand; its complex with zinc has an absorption maximum at 497 nm. Values found by this technique compare favorably with those obtained by atomic absorption spectroscopy.

  14. Polycrystalline CdTe solar cells on elastic substrates

    International Nuclear Information System (INIS)

    Sibinski, M.; Lisik, Z.

    2007-01-01

    The presented article is a report on progress in photovoltaic devices and material processing. A cadmium telluride solar cell as one of the most attractive option for thin-film polycrystalline cell constructions is presented. All typical manufacturing steps of this device, including recrystallisation and junction activation are explained. A new potential field of application for this kind of device - the BIPV (Building Integrated Photovoltaic) is named and discussed. All possible configuration options for this application, according to material properties and exploitation demands are considered. The experimental part of the presented paper is focused on practical implementation of the high - temperature polymer foil as the substrate of the newly designed device by the help of ICSVT (Isothermal Close Space Vapour Transport) technique. The evaluation of the polyester and polyamide foils according to the ICSVT/CSS manufacturing process parameters is described and discussed. A final conclusion on practical verification of these materials is also given. (authors)

  15. Zinc-The key to preventing corrosion

    Science.gov (United States)

    Kropschot, S.J.; Doebrich, Jeff L.

    2011-01-01

    Centuries before it was identified as an element, zinc was used to make brass (an alloy of zinc and copper) and for medicinal purposes. Metallic zinc and zinc oxide were produced in India sometime between the 11th and 14th centuries and in China in the 17th century, although the discovery of pure metallic zinc is credited to the German chemist Andreas Marggraf, who isolated the element in 1746. Refined zinc metal is bluish-white when freshly cast; it is hard and brittle at most temperatures and has relatively low melting and boiling points. Zinc alloys readily with other metals and is chemically active. On exposure to air, it develops a thin gray oxide film (patina), which inhibits deeper oxidation (corrosion) of the metal. The metal's resistance to corrosion is an important characteristic in its use.

  16. Solar energy

    International Nuclear Information System (INIS)

    Kruisheer, N.

    1992-01-01

    In five brief articles product information is given on solar energy applications with special attention to the Netherlands. After an introduction on solar energy availability in the Netherlands the developments in solar boiler techniques are dealt with. Solar water heaters have advantages for the environment, and government subsidies stimulate different uses of such water heaters. Also the developments of solar cells show good prospects, not only for developing countries, but also for the industrialized countries. In brief the developments in solar energy storage and the connection of solar equipment to the grid are discussed. Finally attention is paid to the applications of passive solar energy in the housing construction, the use of transparent thermal insulation and the developments of translucent materials. 18 figs., 18 ills

  17. Solar Imagery

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of solar photographic and illustrated datasets contributed by a number of national and private solar observatories located worldwide....

  18. Solar Features

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of solar feature datasets contributed by a number of national and private solar observatories located worldwide.

  19. Solar Indices

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  20. Effects of serum zinc level on tinnitus.

    Science.gov (United States)

    Berkiten, Güler; Kumral, Tolgar Lütfi; Yıldırım, Güven; Salturk, Ziya; Uyar, Yavuz; Atar, Yavuz

    2015-01-01

    The aim of this study was to assess zinc levels in tinnitus patients, and to evaluate the effects of zinc deficiency on tinnitus and hearing loss. One-hundred patients, who presented to an outpatient clinic with tinnitus between June 2009 and 2014, were included in the study. Patients were divided into three groups according to age: Group I (patients between 18 and 30years of age); Group II (patients between 31 and 60years of age); and Group III (patients between 61 and 78years of age). Following a complete ear, nose and throat examination, serum zinc levels were measured and the severity of tinnitus was quantified using the Tinnitus Severity Index Questionnaire (TSIQ). Patients were subsequently asked to provide a subjective judgment regarding the loudness of their tinnitus. The hearing status of patients was evaluated by audiometry and high-frequency audiometry. An average hearing sensitivity was calculated as the mean value of hearing thresholds between 250 and 20,000Hz. Serum zinc levels between 70 and 120μg/dl were considered normal. The severity and loudness of tinnitus, and the hearing thresholds of the normal zinc level and zinc-deficient groups, were compared. Twelve of 100 (12%) patients exhibited low zinc levels. The mean age of the zinc-deficient group was 65.41±12.77years. Serum zinc levels were significantly lower in group III (p<0.01). The severity and loudness of tinnitus were greater in zinc-deficient patients (p=0.011 and p=0.015, respectively). Moreover, the mean thresholds of air conduction were significantly higher in zinc-deficient patients (p=0.000). We observed that zinc levels decrease as age increases. In addition, there was a significant correlation between zinc level and the severity and loudness of tinnitus. Zinc deficiency was also associated with impairments in hearing thresholds. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Solar Special

    International Nuclear Information System (INIS)

    Van Roekel, A.; Osborne, J.; Schroeter, S.; De Jong, R.; De Saint Jacob, Y.

    2009-01-01

    Solar power is growing much faster than most policymakers and analysts realise. As costs come down and feed-in tariffs go up across Europe, a number of countries have started in pursuit of market leader Germany. But in Germany criticism is growing of the multi-billion-euro support schemes that keep the solar industry booming. In this section of the magazine several articles are dedicated to developments in solar energy in Europe. The first article is an overview story on the strong growing global market for solar cells, mainly thanks to subsidy schemes. The second article is on the position of foreign companies in the solar market in Italy. Article number three is dedicated to the conditions for solar technology companies to establish themselves in the German state of Saxony. Also the fifth article deals with the development of solar cells in Saxony: scientists, plant manufacturers and module producers in Saxony are working on new technologies that can be used to produce solar electricity cost-effectively. The goal is to bring the price down to match that of conventionally generated electricity within the next few years. The sixth article deals with the the solar power market in Belgium, which may be overheated or 'oversubsidized'. Article seven is on France, which used to be a pioneer in solar technology, but now produces only a fraction of the solar output of market leader Germany. However, new attractive feed-in-tariffs are changing the solar landscape drastically

  2. Hybrid zinc oxide conjugated polymer bulk heterojunction solar cells

    NARCIS (Netherlands)

    Beek, W.J.E.; Wienk, M.M.; Kemerink, M.; Yang, X.N.; Janssen, R.A.J.

    2005-01-01

    Bulk heterojunction photovoltaic devices based on blends of a conjugated polymer poly[2-methoxy-5-(3‘,7‘-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) as electron donor and crystalline ZnO nanoparticles (nc-ZnO) as electron acceptor have been studied. Composite nc-ZnO:MDMO-PPV films were cast

  3. Reactivation in vitro of zinc-requiring apo-enzymes by rat liver zinc-thionein

    OpenAIRE

    Udom, Albert O.; Brady, Frank O.

    1980-01-01

    The ability of rat liver zinc-thionein to donate its metal to the apo-enzymes of the zinc enzymes horse liver alcohol dehydrogenase, yeast aldolase, thermolysin, Escherichia coli alkaline phosphatase and bovine erythrocyte carbonic anhydrase was investigated. Zinc-thionein was as good as, or better than, ZnSO4, Zn(CH3CO2)2 or Zn(NO3)2 in donating its zinc to these apo-enzymes. Apo-(alcohol dehydrogenase) could not be reactivated by zinc salts or by zinc-thionein. Incubation of the other apo-e...

  4. Solar Indices - Solar Radio Flux

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  5. A solution process for inverted tandem solar cells

    DEFF Research Database (Denmark)

    Larsen-Olsen, Thue Trofod; Bundgaard, Eva; Sylvester-Hvid, Kristian O.

    2011-01-01

    Tandem solar cells with normal and inverted device geometries were prepared by a solution process. Both device types were based on the use of zinc(II)oxide as the electron transporting layer (ETL). The hole transporting layer (HTL) was either PEDOT:PSS for normal geometry tandem solar cells...... or vanadium(V)oxide in the case of inverted tandem cells. It was found that the inverted tandem solar cells performed comparable or better than the normal geometry devices, showing that the connection structure of vanadium(V)oxide, Ag nanoparticles and zinc(II)oxide functions both as a good recombination...... layer, ensuring serial connection, and as a solvent barrier, protecting the first photoactive layer from processing of the second layer. This successfully demonstrates a tandem solar cell fabrication process fully compatible with state-of-the-art solution based automated production procedures....

  6. Hybrid solar cells from regioregular polythiophene and ZnO nanoparticles

    NARCIS (Netherlands)

    Beek, W.J.E.; Wienk, M.M.; Janssen, R.A.J.

    2006-01-01

    Blends of nanocryst. zinc oxide nanoparticles (nc-ZnO) and regioregular poly(3-hexylthiophene) (P3HT) processed from soln. have been used to construct hybrid polymer-metal oxide bulk-heterojunction solar cells. Thermal annealing of the spin-cast films significantly improves the solar-energy

  7. BWR fuel experience with zinc injection

    International Nuclear Information System (INIS)

    Levin, H.A.; Garcia, S.E.

    1995-01-01

    In 1982 a correlation between low primary recirculation system dose rates in BWR's and the presence of ionic zinc in reactor water was identified. The source of the zinc was primarily from Admiralty brass condensers. Plants with brass condensers are called ''natural zinc'' plants. Brass condensers were also a source of copper that was implicated in crude induced localized corrosion (CILC) fuel failures. In 1986 the first BWR intentionally injected zinc for the benefits of dose rate control. Although zinc alone was never implicated in fuel degradation of failures, a comprehensive fuel surveillance program was initiated to monitor fuel performance. Currently there are 14 plants that are injecting zinc. Six of these plants are also on hydrogen water chemistry. This paper describes the effect on both Zircaloy corrosion and the cruding characteristics as a result of these changes in water chemistry. Fuel rod corrosion was found to be independent of the specific water chemistry of the plants. The corrosion behavior was the same with the additions of zinc alone or zinc plus hydrogen and well within the operating experience for fuel without either of these additions. No change was observed in the amounts of crude deposited on the fuel rods, both for the adherent and loosely held deposits. One of the effects of the zinc addition was the trend to form more of the zinc rich iron spinel in the fuel deposits rather than the hematite deposits that are predominantly formed with non additive water chemistry

  8. Zinc and the modulation of redox homeostasis

    Science.gov (United States)

    Oteiza, Patricia I.

    2012-01-01

    Zinc, a redox inactive metal, has been long viewed as a component of the antioxidant network, and growing evidence points to its involvement in redox-regulated signaling. These actions are exerted through several mechanisms based on the unique chemical and functional properties of zinc. Overall, zinc contributes to maintain the cell redox balance through different mechanisms including: i) the regulation of oxidant production and metal-induced oxidative damage; ii) the dynamic association of zinc with sulfur in protein cysteine clusters, from which the metal can be released by nitric oxide, peroxides, oxidized glutathione and other thiol oxidant species; iii) zinc-mediated induction of the zinc-binding protein metallothionein, which releases the metal under oxidative conditions and act per se scavenging oxidants; iv) the involvement of zinc in the regulation of glutathione metabolism and of the overall protein thiol redox status; and v) a direct or indirect regulation of redox signaling. Findings of oxidative stress, altered redox signaling, and associated cell/tissue disfunction in cell and animal models of zinc deficiency, stress the relevant role of zinc in the preservation of cell redox homeostasis. However, while the participation of zinc in antioxidant protection, redox sensing, and redox-regulated signaling is accepted, the involved molecules, targets and mechanisms are still partially known and the subject of active research. PMID:22960578

  9. Coupled solar still, solar heater

    Energy Technology Data Exchange (ETDEWEB)

    Davison, R R; Harris, W B; Moor, D H; Delyannis, A; Delyannis, E [eds.

    1976-01-01

    Computer simulation of combinations of solar stills and solar heaters indicates the probable economic advantage of such an arrangement in many locations if the size of the heater is optimized relative to that of the still. Experience with various low cost solar heaters is discussed.

  10. Solar Sailing

    Science.gov (United States)

    Johnson, Les

    2009-01-01

    Solar sailing is a topic of growing technical and popular interest. Solar sail propulsion will make space exploration more affordable and offer access to destinations within (and beyond) the solar system that are currently beyond our technical reach. The lecture will describe solar sails, how they work, and what they will be used for in the exploration of space. It will include a discussion of current plans for solar sails and how advanced technology, such as nanotechnology, might enhance their performance. Much has been accomplished recently to make solar sail technology very close to becoming an engineering reality and it will soon be used by the world s space agencies in the exploration of the solar system and beyond. The first part of the lecture will summarize state-of-the-art space propulsion systems and technologies. Though these other technologies are the key to any deep space exploration by humans, robots, or both, solar-sail propulsion will make space exploration more affordable and offer access to distant and difficult destinations. The second part of the lecture will describe the fundamentals of space solar sail propulsion and will describe the near-, mid- and far-term missions that might use solar sails as a propulsion system. The third part of the lecture will describe solar sail technology and the construction of current and future sailcraft, including the work of both government and private space organizations.

  11. 65Zinc and endogenous zinc content and distribution in islets in relationship to insulin content

    International Nuclear Information System (INIS)

    Figlewicz, D.P.; Forhan, S.E.; Hodgson, A.T.; Grodsky, G.M.

    1984-01-01

    Uptake of 65 Zn and distribution of 65 Zn, total zinc, and insulin were measured in rat islets and islet granules under different conditions of islet culture. Specific activity of islet zinc ( 65 Zn/zinc) was less than 15% that of extracellular zinc even after 48 h. In contrast, once in the islet, 65 Zn approached 70% of equilibrium with granular zinc in 24 h and apparent equilibrium by 48 h. During a 24-h culture, at either high or low glucose, reduction of both islet zinc and insulin occurred. However, zinc depletion was greater than that predicted if zinc loss was proportional to insulin depletion and occurred only from the granular compartment, which represents only one third of the total islet zinc. Extension of culture to 48 h caused additional insulin depletion, but islet zinc was unchanged. Omission of calcium during the 48-h culture caused a predicted increase in insulin retention, presumably by inhibiting secretion; however, zinc retention was not increased proportionately. Pretreatment of rats with tolbutamide caused a massive depletion of insulin stored in isolated islets, with little change in total islet zinc; subsequent culture of these islets resulted in a greater loss of granular zinc than predicted from the small loss of granular insulin. None of the conditions tested affected the percentage of either 65 Zn or total zinc that was distributed in the islet granules. Results show that zinc exists in a metabolically labile islet compartment(s) as well as in secretory granules; and extra-granular zinc, although not directly associated with insulin storage, may act as a reservoir for granular zinc and may regulate insulin synthesis, storage, and secretion in ways as yet unknown

  12. Neodymium conversion layers formed on zinc powder for improving electrochemical properties of zinc electrodes

    International Nuclear Information System (INIS)

    Zhu Liqun; Zhang Hui; Li Weiping; Liu Huicong

    2008-01-01

    Zinc powder, as active material of secondary alkaline zinc electrode, can greatly limit the performance of zinc electrode due to corrosion and dendritic growth of zinc resulting in great capacity-loss and short cycle life of the electrode. This work is devoted to modification study of zinc powder with neodymium conversion films coated directly onto it using ultrasonic immersion method for properties improvement of zinc electrodes. Scanning electron microscopy and other characterization techniques are applied to prove that neodymium conversion layers are distributing on the surface of modified zinc powder. The electrochemical performance of zinc electrodes made of such modified zinc powder is investigated through potentiodynamic polarization, potentiostatic polarization and cyclic voltammetry. The neodymium conversion films are found to have a significant effect on inhibition corrosion capability of zinc electrode in a beneficial way. It is also confirmed that the neodymium conversion coatings can obviously suppress dendritic growth of zinc electrode, which is attributed to the amelioration of deposition state of zinc. Moreover, the results of cyclic voltammetry reveal that surface modification of zinc powder enhances the cycle performance of the electrode mainly because the neodymium conversion films decrease the amounts of ZnO or Zn(OH) 2 dissolved in the electrolyte

  13. Quadrupole interaction in zinc metal

    International Nuclear Information System (INIS)

    Vetterling, W.T.; Pound, R.V.

    1977-01-01

    To allow measurement of the quadrupole interaction in zinc metal, the enriched ZnO was reduced to zinc metal powder and compressed into a pill of thickness 1.4 gm/cm 2 . Sources were made by diffusing 20 mCi of 67 Ga into sintered copper pills. The transducer was based on a cylinder of PZT-4 with 1 / 2 -inch length and could cover linearly a velocity range of +-100 μ/s at 200 Hz. The multiscalar was a modified Northern model NS600, with a minimum dwell time of 20 μs, and with a 10-count buffer at the input to eliminate deadtime from memory cycling

  14. Thermo-electro-chemical storage (TECS) of solar energy

    International Nuclear Information System (INIS)

    Wenger, Erez; Epstein, Michael; Kribus, Abraham

    2017-01-01

    Highlights: • A solar plant with thermally regenerative battery unifies energy conversion and storage. • Storage is a flow battery with thermo-chemical charging and electro-chemical discharging. • Sodium-sulfur and zinc-air systems are investigated as candidate storage materials. • Theoretical solar to electricity efficiencies of over 60% are predicted. • Charging temperature can be lowered with hybrid carbothermic reduction. - Abstract: A new approach for solar electricity generation and storage is proposed, based on the concept of thermally regenerative batteries. Concentrated sunlight is used for external thermo-chemical charging of a flow battery, and electricity is produced by conventional electro-chemical discharge of the battery. The battery replaces the steam turbine, currently used in commercial concentrated solar power (CSP) plants, potentially leading to much higher conversion efficiency. This approach offers potential performance, cost and operational advantages compared to existing solar technologies, and to existing storage solutions for management of an electrical grid with a significant contribution of intermittent solar electricity generation. Here we analyze the theoretical conversion efficiency for new thermo-electro-chemical storage (TECS) plant schemes based on the electro-chemical systems of sodium-sulfur (Na-S) and zinc-air. The thermodynamic upper limit of solar to electricity conversion efficiency for an ideal TECS cycle is about 60% for Na-S at reactor temperature of 1550 K, and 65% for the zinc-air system at 1750 K, both under sunlight concentration of 3000. A hybrid process with carbothermic reduction in the zinc-air system reaches 60% theoretical efficiency at the more practical conditions of reaction temperature <1200 K and concentration <1000. Practical TECS plant efficiency, estimated from these upper limits, may then be much higher compared to existing solar electricity technologies. The technical and economical

  15. Optimization of material/device parameters of CdTe photovoltaic for solar cells applications

    Science.gov (United States)

    Wijewarnasuriya, Priyalal S.

    2016-05-01

    Cadmium telluride (CdTe) has been recognized as a promising photovoltaic material for thin-film solar cell applications due to its near optimum bandgap of ~1.5 eV and high absorption coefficient. The energy gap is near optimum for a single-junction solar cell. The high absorption coefficient allows films as thin as 2.5 μm to absorb more than 98% of the above-bandgap radiation. Cells with efficiencies near 20% have been produced with poly-CdTe materials. This paper examines n/p heterostructure device architecture. The performance limitations related to doping concentrations, minority carrier lifetimes, absorber layer thickness, and surface recombination velocities at the back and front interfaces is assessed. Ultimately, the paper explores device architectures of poly- CdTe and crystalline CdTe to achieve performance comparable to gallium arsenide (GaAs).

  16. Recent developments in low cost silicon solar cells for terrestrial applications. [sheet production methods

    Science.gov (United States)

    Leipold, M. H.

    1978-01-01

    A variety of techniques may be used for photovoltaic energy systems. Concentrated or not concentrated sunlight may be employed, and a number of materials can be used, including silicon, gallium arsenide, cadmium sulfide, and cadmium telluride. Most of the experience, however, has been obtained with silicon cells employed without sunlight concentration. An industrial base exists at present for producing solar cells at a price in the range from $15 to $30 per peak watt. A major federal program has the objective to reduce the price of power provided by silicon solar systems to approximately $1 per peak watt in the early 1980's and $0.50 per watt by 1986. The approaches considered for achieving this objective are discussed.

  17. Electroplated zinc-cobalt alloy

    International Nuclear Information System (INIS)

    Carpenter, D.E.O.S.; Farr, J.P.G.

    2005-01-01

    Recent work on the deposition and use of ectrodeposited zinc-cobalt alloys is surveyed. Alloys containing lower of Nuclear quantities of cobalt are potentially more useful. The structures of the deposits is related to their chemical and mechanical properties. The inclusion of oxide and its role in the deposition mechanism may be significant. Chemical and engineering properties relate to the metallurgical structure of the alloys, which derives from the mechanism of deposition. The inclusion of oxides and hydroxides in the electroplate may provide evidence for this mechanism. Electrochemical impedance measurements have been made at significant deposition potentials, in alkaline electrolytes. These reveal a complex electrode behaviour which depends not only on the electrode potential but on the Co content of the electrolyte. For the relevant range of cathodic potential zinc-cobalt alloy electrodeposition occurs through a stratified interface. The formation of an absorbed layer ZnOH/sup +/ is the initial step, this inhibits the deposition of cobalt at low cathodic potentials, so explaining its 'anomalous deposition'. A porous layer of zinc forms on the adsorbed ZnOH/sup +/ at underpotential. As the potential becomes more cathodic, cobalt co- deposits from its electrolytic complex forming a metallic solid solution of Co in Zn. In electrolytes containing a high concentration of cobalt a mixed entity (ZnCo)/sub +/ is assumed to adsorb at the cathode from which a CoZn intermetallic deposits. (author)

  18. Effects of dietary zinc status on seizure susceptibility and hippocampal zinc content in the El (epilepsy) mouse.

    Science.gov (United States)

    Fukahori, M; Itoh, M

    1990-10-08

    The effects of dietary zinc status on the development of convulsive seizures, and zinc concentrations in discrete hippocampal areas and other parts of the limbic system were studied in the El mouse model receiving zinc-adequate, zinc-deficient or zinc-loaded diets. Seizure susceptibility of the El mouse was increased by zinc deficiency, and decreased by zinc loading, while an adequate diet had no effect. Zinc loading was accompanied by a marked increase in hippocampal zinc content in the El mouse. Conversely, hippocampal zinc content declined in the El mouse fed a zinc-deficient diet. These results suggest that zinc may have a preventive effect on the development of seizures in the El mouse, and hippocampal zinc may play an important role in the pathophysiology of convulsive seizures of epilepsy.

  19. Acetic acid-confined synthesis of uniform three-dimensional (3D) bismuth telluride nanocrystals consisting of few-quintuple-layer nanoplatelets

    KAUST Repository

    Yuan, Qiang; Radar, Kelly; Hussain, Muhammad Mustafa

    2011-01-01

    High-selectivity, uniform three-dimensional (3D) flower-like bismuth telluride (Bi2Te3) nanocrystals consisting of few-quintuple-layer nanoplatelets with a thickness down to 4.5 nm were synthesized for the first time by a facile, one-pot polyol method with acetic acid as the structure-director. Micrometre-sized 2D films and honeycomb-like spheres can be obtained using the uniform 3D Bi2Te3 nanocrystals as building blocks. © The Royal Society of Chemistry 2011.

  20. Zinc in Cellular Regulation: The Nature and Significance of "Zinc Signals".

    Science.gov (United States)

    Maret, Wolfgang

    2017-10-31

    In the last decade, we witnessed discoveries that established Zn 2+ as a second major signalling metal ion in the transmission of information within cells and in communication between cells. Together with Ca 2+ and Mg 2+ , Zn 2+ covers biological regulation with redox-inert metal ions over many orders of magnitude in concentrations. The regulatory functions of zinc ions, together with their functions as a cofactor in about three thousand zinc metalloproteins, impact virtually all aspects of cell biology. This article attempts to define the regulatory functions of zinc ions, and focuses on the nature of zinc signals and zinc signalling in pathways where zinc ions are either extracellular stimuli or intracellular messengers. These pathways interact with Ca 2+ , redox, and phosphorylation signalling. The regulatory functions of zinc require a complex system of precise homeostatic control for transients, subcellular distribution and traffic, organellar homeostasis, and vesicular storage and exocytosis of zinc ions.

  1. Zinc and immunity: An essential interrelation.

    Science.gov (United States)

    Maares, Maria; Haase, Hajo

    2016-12-01

    The significance of the essential trace element zinc for immune function has been known for several decades. Zinc deficiency affects immune cells, resulting in altered host defense, increased risk of inflammation, and even death. The micronutrient zinc is important for maintenance and development of immune cells of both the innate and adaptive immune system. A disrupted zinc homeostasis affects these cells, leading to impaired formation, activation, and maturation of lymphocytes, disturbed intercellular communication via cytokines, and weakened innate host defense via phagocytosis and oxidative burst. This review outlines the connection between zinc and immunity by giving a survey on the major roles of zinc in immune cell function, and their potential consequences in vivo. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. BWR radiation buildup control with ionic zinc

    International Nuclear Information System (INIS)

    Marble, W.J.; Wood, C.J.; Leighty, C.E.; Green, T.A.

    1986-01-01

    In 1983 a hypothesis was disclosed which suggested that the presence of ionic zinc in the reactor water of the BWR could reduce radiation buildup. This hypothesis was developed from correlations of plant data, and subsequently, from laboratory experiments which demonstrated clearly that ionic zinc inhibits the corrosion of stainless steel. The benefits of zinc addition have been measured at the Vallecitos Nuclear Center under and EPRI/GE project. Experimentation and analyses have been performed to evaluate the impact of intentional zinc addition on the IGSCC characteristics of primary system materials and on the performance of the nuclear fuel. It has been concluded that no negative effects are expected. The author conclude that the intentional addition of ionic zinc to the BWR reactor water at a concentration of approximately 10 ppb will provide major benefits in controlling the Co-60 buildup on primary system stainless steel surfaces. The intentional addition of zinc is now a qualified technique for use in BWRs

  3. Preparation of transparent conducting zinc oxide films by rf reactive sputtering

    International Nuclear Information System (INIS)

    Vasanelli, L.; Valentini, A.; Losacco, A.

    1986-01-01

    Transparent conducting zinc oxide films have been prepared by reactive sputtering in a Ar/H/sub 2/ mixture. The optical and electrical properties of the films are presented and discussed. The effects of some post-deposition thermal treatment have been also investigated. ZnO/CdTe heterojunctions have been prepared by sputtering ZnO films on CdTe single crystals. The photovoltaic conversion efficiencies of the obtained solar cells was 6.8%

  4. Directed spatial organization of zinc oxide nanostructures

    Science.gov (United States)

    Hsu, Julia [Albuquerque, NM; Liu, Jun [Richland, WA

    2009-02-17

    A method for controllably forming zinc oxide nanostructures on a surface via an organic template, which is formed using a stamp prepared from pre-defined relief structures, inking the stamp with a solution comprising self-assembled monolayer (SAM) molecules, contacting the stamp to the surface, such as Ag sputtered on Si, and immersing the surface with the patterned SAM molecules with a zinc-containing solution with pH control to form zinc oxide nanostructures on the bare Ag surface.

  5. Activity incorporation into zinc doped PWR oxides

    International Nuclear Information System (INIS)

    Maekelae, Kari

    1998-01-01

    Activity incorporation into the oxide layers of PWR primary circuit constructional materials has been studied in Halden since 1993. The first zinc injection tests showed that zinc addition resulted in thinner oxide layers on new metal surfaces and reduced further incorporation of activity into already existing oxides. These tests were continued to find out the effects of previous zinc additions on the pickup of activity onto the surface oxides which were subsequently exposed to zinc-free coolant. The results showed that previous zinc addition will continue to reduce the rate of Co-60 build-up on out-of-core surfaces in subsequent exposure to zinc-free coolants. However, the previous Zn free test was performed for a relatively short period of time and the water chemistry programme was continued to find out the long term effects for extended periods without zinc. The activity incorporation into the stainless steel oxides started to increase as soon as zinc dosing to the coolant was stopped. The Co-60 concentration was lowest on all of the coupons which were first oxidised in Zn containing primary coolant. After the zinc injection period the thickness of the oxides increased, but activity in the oxide films did not increase at the same rate. This could indicate that zinc in the oxide blocks the adsorption sites for Co-60 incorporation. The Co-60 incorporation rate into the oxides on Inconel 600 seemed to be linear whether the oxide was pre-oxidised with or without Zn. The results indicate that zinc can either replace or prevent cobalt transport in the oxides. The results show that for zinc injection to be effective it should be carried out continuously. Furthermore the actual mechanism by which Zn inhibits the activity incorporation into the oxides is still not clear. Therefore, additional work has to follow with specified materials to verify the conclusions drawn in this work. (author)

  6. Plasmonic silicon solar cells : Impact of material quality and geometry

    NARCIS (Netherlands)

    Pahud, C.; Isabella, O.; Naqavi, A.; Haug, F.J.; Zeman, M.; Herzig, H.P.; Ballif, C.

    2013-01-01

    We study n-i-p amorphous silicon solar cells with light-scattering nanoparticles in the back reflector. In one configuration, the particles are fully embedded in the zinc oxide buffer layer; In a second configuration, the particles are placed between the buffer layer and the flat back electrode. We

  7. Power losses in bilayer inverted small molecule organic solar cells

    KAUST Repository

    Trinh, Cong; Bakke, Jonathan R.; Brennan, Thomas P.; Bent, Stacey F.; Navarro, Francisco; Bartynski, Andrew; Thompson, Mark E.

    2012-01-01

    Inverted bilayer organic solar cells using copper phthalocyanine (CuPc) as a donor and C60 as an acceptor with the structure: glass/indium tin oxide (ITO)/ZnO/C60/CuPc/MoO3/Al, in which the zinc oxide (ZnO) was deposited by atomic layer deposition

  8. Non-Chromate Passivation of Zinc

    DEFF Research Database (Denmark)

    Tang, Peter Torben; Bech-Nielsen, G.

    1993-01-01

    Phos). The treatments are within the same concentration region, and they have a mutual pat-ent pending. Although some tests still need to be conducted, the following aspects are clear at the present time: The general appearance of the passivated zinc surface is very similar to a standard yellow chromate treatment...... successfully. The corrosion resistance against white rust on zinc and zinc alloys is just as good as that of yellow chromate, although the result de-pends on the corrosion test method as well as on the nature of the zinc substrate pas-sivated. The passivation procedure is simply a dip for approxi-mately 2...

  9. Status of zinc injection in PWRs

    Energy Technology Data Exchange (ETDEWEB)

    Bergmann, C.A. [Westinghouse Electric Co., Pittsburgh, PA (United States)

    1995-03-01

    Based on laboratory and other studies, it was concluded that zinc addition in a PWR primary coolant should result in reduced Alloy 600 PWSCC and general corrosion rates of the materials of construction. Because of these positive results, a Westinghouse Owner`s Subgroup, EPRI, and Westinghouse provided funds to continue the development and application of zinc in an operating plant. As part of the program, Southern Operating Nuclear Company agreed to operate the Farley 2 plant with zinc addition as a demonstration test of the effectiveness of zinc. Since zinc is incorporated in the corrosion oxide film on the primary system surfaces and Farley 2 is a mature plant, it was estimated that about 10 kgs of zinc would be needed to condition the plant before an equilibrium value in the coolant would be reached. The engineered aspects of a Zinc Addition and Monitoring System (ZAMS) considered such items as the constitutents, location, sizing and water supply of the ZAMS. Baseline data such as the PWSCC history of the Alloy 600 steam generator tubing, fuel oxide thickness, fuel crud deposits, radiation levels, and RCP seal leak-off rates were obtained before zinc addition is initiated. This presentation summarizes some of the work performed under the program, and the status of zinc injection in the Farley 2 plant.

  10. Zinc absorption in inflammatory bowel disease

    International Nuclear Information System (INIS)

    Valberg, L.S.; Flanagan, P.R.; Kertesz, A.; Bondy, D.C.

    1986-01-01

    Zinc absorption was measured in 29 patients with inflammatory bowel disease and a wide spectrum of disease activity to determine its relationship to disease activity, general nutritional state, and zinc status. Patients with severe disease requiring either supplementary oral or parenteral nutrition were excluded. The mean 65ZnCl2 absorption, in the patients, determined using a 65Zn and 51Cr stool-counting test, 45 +/- 17% (SD), was significantly lower than the values, 54 +/- 16%, in 30 healthy controls, P less than 0.05. Low 65ZnCl2 absorption was related to undernutrition, but not to disease activity in the absence of undernutrition or to zinc status estimated by leukocyte zinc measurements. Mean plasma zinc or leukocyte zinc concentrations in patients did not differ significantly from controls, and only two patients with moderate disease had leukocyte zinc values below the 5th percentile of normal. In another group of nine patients with inflammatory bowel disease of mild-to-moderate severity and minimal nutritional impairment, 65Zn absorption from an extrinsically labeled turkey test meal was 31 +/- 10% compared to 33 +/- 7% in 17 healthy controls, P greater than 0.1. Thus, impairment in 65ZnCl2 absorption in the patients selected for this study was only evident in undernourished persons with moderate or severe disease activity, but biochemical evidence of zinc deficiency was uncommon, and clinical features of zinc depletion were not encountered

  11. Maternal Zinc Intakes and Homeostatic Adjustments during Pregnancy and Lactation

    Science.gov (United States)

    Donangelo, Carmen Marino; King, Janet C.

    2012-01-01

    Zinc plays critical roles during embryogenesis, fetal growth, and milk secretion, which increase the zinc need for pregnancy and lactation. Increased needs can be met by increasing the dietary zinc intake, along with making homeostatic adjustments in zinc utilization. Potential homeostatic adjustments include changes in circulating zinc, increased zinc absorption, decreased zinc losses, and changes in whole body zinc kinetics. Although severe zinc deficiency during pregnancy has devastating effects, systematic reviews and meta-analysis of the effect of maternal zinc supplementation on pregnancy outcomes have consistently shown a limited benefit. We hypothesize, therefore, that zinc homeostatic adjustments during pregnancy and lactation improve zinc utilization sufficiently to provide the increased zinc needs in these stages and, therefore, mitigate immediate detrimental effects due to a low zinc intake. The specific questions addressed are the following: How is zinc utilization altered during pregnancy and lactation? Are those homeostatic adjustments influenced by maternal zinc status, dietary zinc, or zinc supplementation? These questions are addressed by critically reviewing results from published human studies on zinc homeostasis during pregnancy and lactation carried out in different populations worldwide. PMID:22852063

  12. Development of zinc oxide nanoparticle by sonochemical method and study of their physical and optical properties

    International Nuclear Information System (INIS)

    Khan, Samreen Heena; Suriyaprabha, R.; Pathak, Bhawana; Fulekar, M. H.

    2016-01-01

    With the miniaturization of crystal size, the fraction of under-coordinated surface atoms becomes dominant, and hence, materials in the nano-regime behave very differently from the similar material in a bulk. Zinc oxide (ZnO), particularly, exhibits extraordinary properties such as a wide direct band gap (3.37 eV), large excitation binding energy (60 meV), low refractive index (1.9), stability to intense ultraviolet (UV) illumination, resistance to high-energy irradiation, and lower toxicity as compared to other semiconductors. This very property makes Zinc Oxide a potential candidate in many application fields, particularly as a prominent semiconductor. Zinc Oxide plays a significant role in many technological advances with its application in semiconductor mediated photocatalytic processes and sensor, solar cells and others. In present study, Zinc Oxide (ZnO) has been synthesized using three different precursors by sonochemical method. Zinc Acetate Dihydrate, Zinc Nitrate Hexahydrate and Zinc Sulphate Heptahydrate used as a precursor for the synthesis process. The synthesized ZnO nanoparticle has been found under the range of ∼50 nm. Zinc oxide nanoparticles were characterized using different characterizing tools. The as-synthesized ZnO was characterized by Fourier Transform-Infrared Spectroscopy (FT-IR) for the determination of functional group; Scanning Electron Microscopy equipped with Energy Dispersive Spectroscopy (SEM-EDS) for Morphology and elemental detection respectively, Transmission Electron Microscopy for Particle size distribution and morphology and X-Ray Diffraction (XRD) for the confirmation of crystal structure of the nanomaterial. The optical properties of the ZnO were examined by UV-VIS spectroscopy equipped with Diffuse Reflectance spectroscopy (DRS) confirmed the optical band gap of ZnO-3 around 3.23 eV resembles with the band gap of bulk ZnO (3.37eV). The TEM micrograph of the as-synthesized material showed perfectly spherical shaped

  13. Development of zinc oxide nanoparticle by sonochemical method and study of their physical and optical properties

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Samreen Heena, E-mail: samreen.heena.khan@gmail.com; Suriyaprabha, R. [Centre for Nanosciences, Central University of Gujarat, Gandhinagar, India- 382030 (India); Pathak, Bhawana, E-mail: bhawana.pathak@cug.ac.in; Fulekar, M. H., E-mail: mhfulekar@yahoo.com [School of Environment and Sustainable Development, Central University of Gujarat, Gandhinagar, India- 382030 (India)

    2016-04-13

    With the miniaturization of crystal size, the fraction of under-coordinated surface atoms becomes dominant, and hence, materials in the nano-regime behave very differently from the similar material in a bulk. Zinc oxide (ZnO), particularly, exhibits extraordinary properties such as a wide direct band gap (3.37 eV), large excitation binding energy (60 meV), low refractive index (1.9), stability to intense ultraviolet (UV) illumination, resistance to high-energy irradiation, and lower toxicity as compared to other semiconductors. This very property makes Zinc Oxide a potential candidate in many application fields, particularly as a prominent semiconductor. Zinc Oxide plays a significant role in many technological advances with its application in semiconductor mediated photocatalytic processes and sensor, solar cells and others. In present study, Zinc Oxide (ZnO) has been synthesized using three different precursors by sonochemical method. Zinc Acetate Dihydrate, Zinc Nitrate Hexahydrate and Zinc Sulphate Heptahydrate used as a precursor for the synthesis process. The synthesized ZnO nanoparticle has been found under the range of ∼50 nm. Zinc oxide nanoparticles were characterized using different characterizing tools. The as-synthesized ZnO was characterized by Fourier Transform-Infrared Spectroscopy (FT-IR) for the determination of functional group; Scanning Electron Microscopy equipped with Energy Dispersive Spectroscopy (SEM-EDS) for Morphology and elemental detection respectively, Transmission Electron Microscopy for Particle size distribution and morphology and X-Ray Diffraction (XRD) for the confirmation of crystal structure of the nanomaterial. The optical properties of the ZnO were examined by UV-VIS spectroscopy equipped with Diffuse Reflectance spectroscopy (DRS) confirmed the optical band gap of ZnO-3 around 3.23 eV resembles with the band gap of bulk ZnO (3.37eV). The TEM micrograph of the as-synthesized material showed perfectly spherical shaped

  14. Solar Photovoltaic

    OpenAIRE

    Wang, Chen; Lu, Yuefeng

    2016-01-01

    In the 21st century, human demand for new energy sources is urgent, because the traditional fossil energy is unable to meet human needs, and the fossil resource will make pollution, in this situation, solar energy gradually into the vision of scientists. As science advances, humans can already extensive use of solar energy to generate electricity. Solar energy is an inexhaustible and clean energy. In the global energy crisis, environmental pollution is the growing problem of today. The us...

  15. Solar magnetohydrodynamics

    International Nuclear Information System (INIS)

    Priest, E.R.

    1982-01-01

    The book serves several purposes. First set of chapters gives a concise general introduction to solar physics. In a second set the basic methods of magnetohydrodynamics are developed. A third set of chapters is an account of current theories for observed phenomena. The book is suitable for a course in solar physics and it also provides a comprehensive review of present magnetohydrodynamical models in solar physics. (SC)

  16. Solar constraints

    International Nuclear Information System (INIS)

    Provost, J.

    1984-01-01

    Accurate tests of the theory of stellar structure and evolution are available from the Sun's observations. The solar constraints are reviewed, with a special attention to the recent progress in observing global solar oscillations. Each constraint is sensitive to a given region of the Sun. The present solar models (standard, low Z, mixed) are discussed with respect to neutrino flux, low and high degree five-minute oscillations and low degree internal gravity modes. It appears that actually there do not exist solar models able to fully account for all the observed quantities. (Auth.)

  17. Solar Simulator

    Science.gov (United States)

    1981-01-01

    Oriel Corporation's simulators have a high pressure xenon lamp whose reflected light is processed by an optical system to produce a uniform solar beam. Because of many different types of applications, the simulators must be adjustable to replicate many different areas of the solar radiation spectrum. Simulators are laboratory tools for such purposes as testing and calibrating solar cells, or other solar energy systems, testing dyes, paints and pigments, pharmaceuticals and cosmetic preparations, plant and animal studies, food and agriculture studies and oceanographic research.

  18. Monodispersed Zinc Oxide Nanoparticle-Dye Dyads and Triads

    Energy Technology Data Exchange (ETDEWEB)

    Gladfelter, Wayne L. [Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Chemistry; Blank, David A. [Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Chemistry; Mann, Kent R. [Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Chemistry

    2017-06-22

    The overall energy conversion efficiency of photovoltaic cells depends on the combined efficiencies of light absorption, charge separation and charge transport. Dye-sensitized solar cells are photovoltaic devices in which a molecular dye absorbs light and uses this energy to initiate charge separation. The most efficient dye-sensitized solar cells (DSSCs) use nanocrystal titanium dioxide films to which are attached ruthenium complexes. Numerous studies have provided valuable insight into the dynamics of these and analogous photosystems, but the lack of site homogeneity in binding dye molecules to metal oxide films and nanocrystals (NCs) is a significant impediment to extracting fundamental details about the electron transfer across the interface. Although zinc oxide is emerging as a potential semiconducting component in DSSCs, there is less known about the factors controlling charge separation across the dye/ZnO interface. Zinc oxide crystallizes in the wurtzite lattice and has a band gap of 3.37 eV. One of the features that makes ZnO especially attractive is the remarkable ability to control the morphology of the films. Using solution deposition processes, one can prepare NCs, nanorods and nanowires having a variety of shapes and dimensions. This project solved problems associated with film heterogeneity through the use of dispersible sensitizer/ZnO NC ensembles. The overarching goal of this research was to study the relationship between structure, energetics and dynamics in a set of synthetically controlled donor-acceptor dyads and triads. These studies provided access to unprecedented understanding of the light absorption and charge transfer steps that lie at the heart of DSSCs, thus enabling significant future advances in cell efficiencies. The approach began with the construction of well-defined dye-NC dyads that were sufficiently dispersible to allow the use of state of the art pulsed laser spectroscopic and kinetic methods to understand the charge transfer

  19. Comparative effects of zinc oxide nanoparticles and dissolved zinc on zebrafish embryos and eleuthero-embryos: Importance of zinc ions

    NARCIS (Netherlands)

    Brun, N.R.; Lenz, M.; Wehrli, B.; Fent, K.

    2014-01-01

    The increasing use of zinc oxide nanoparticles (nZnO) and their associated environmental occurrence make it necessary to assess their potential effects on aquatic organisms. Upon water contact, nZnO dissolve partially to zinc (Zn(II)). To date it is not yet completely understood, whether effects of

  20. Effect of Consuming Zinc-fortified Bread on Serum Zinc and Iron Status of Zinc-deficient Women: A Double Blind, Randomized Clinical Trial.

    Science.gov (United States)

    Badii, Akbar; Nekouei, Niloufar; Fazilati, Mohammad; Shahedi, Mohammad; Badiei, Sajad

    2012-03-01

    After iron deficiency, zinc deficiency is the major micronutrient deficiency in developing countries, and staple food fortification is an effective strategy to prevent and improve it among at-risk-populations. No action has been taken to reduce zinc deficiency via flour fortification so far in Iran, and little is known about the influence of zinc fortification of flour on serum zinc and the iron status, and also about the optimum and effective amount of zinc compound that is used in food fortification. The objective of this study is to evaluate the influence of consuming zinc-fortified breads on the zinc and iron status in the blood serum. In this study, three types of bread were prepared from non-fortified and fortified flours, with 50 and 100 ppm elemental zinc in the form of sulfate. Eighty zinc-deficient women aged 19 to 49 years were randomly assigned to three groups; The volunteers received, daily, (1) a non-fortified bread, (2) a high-zinc bread, and (3) a low-zinc bread for one month. Serum zinc and iron were measured by Atomic Absorption before and after the study. Results showed a significant increase in serum zinc and iron levels in all groups (p 0.05). Absorption of zinc and iron in the group that consumed high-zinc bread was significantly greater than that in the group that received low-zinc bread (p bread improved iron absorption.

  1. Large-scale synthesis of lead telluride (PbTe) nanotube-based nanocomposites with tunable morphology, crystallinity and thermoelectric properties

    Science.gov (United States)

    Park, Kee-Ryung; Cho, Hong-Baek; Song, Yoseb; Kim, Seil; Kwon, Young-Tae; Ryu, Seung Han; Lim, Jae-Hong; Lee, Woo-Jin; Choa, Yong-Ho

    2018-04-01

    A few millimeter-long lead telluride (PbTe) hollow nanofibers with thermoelectric properties was synthesized for the first time with high through manner via three-step sequential process of electrospinning, electrodeposition and cationic exchange reaction. As-synthesized electrospun Ag nanofibers with ultra-long aspect ratio of 10,000 were Te electrodeposited to obtain silver telluride nanotubes and underwent cationic exchange reaction in Pb(NO3)2 solution to obtain polycrystalline PbTe nanotubes with average diameter of 100 nm with 20 nm of wall thickness. Variation of the Ag-to-Pb ratio in the AgxTey-PbTe nanocomposites during the cationic exchange reaction enabled to control the thermoelectric properties of resulting 1D hollow nanofibers. The diameter of Ag nanofiber is the key factor to determine the final dimension of the PbTe nanotubes in the topotactic transformation and the content of Ag ion leads to the enhancement of thermoelectric properties in the AgxTey-PbTe nanocomposites. The synthesized 1D nanocomposite mats showed the highest value of Seebeck coefficient of 433 μV/K (at 300 K) when the remained Ag content was 30%, while the power factor reached highest to 0.567 μW/mK2 for the pure PbTe nanotubes. The enhancement of thermoelectric properties and the composite crystallinity are elucidated with relation to Ag contents in the resulting 1D nanocomposites.

  2. The Potential for Zinc Stable Isotope Techniques and Modelling to Determine Optimal Zinc Supplementation

    Directory of Open Access Journals (Sweden)

    Cuong D. Tran

    2015-05-01

    Full Text Available It is well recognised that zinc deficiency is a major global public health issue, particularly in young children in low-income countries with diarrhoea and environmental enteropathy. Zinc supplementation is regarded as a powerful tool to correct zinc deficiency as well as to treat a variety of physiologic and pathologic conditions. However, the dose and frequency of its use as well as the choice of zinc salt are not clearly defined regardless of whether it is used to treat a disease or correct a nutritional deficiency. We discuss the application of zinc stable isotope tracer techniques to assess zinc physiology, metabolism and homeostasis and how these can address knowledge gaps in zinc supplementation pharmacokinetics. This may help to resolve optimal dose, frequency, length of administration, timing of delivery to food intake and choice of zinc compound. It appears that long-term preventive supplementation can be administered much less frequently than daily but more research needs to be undertaken to better understand how best to intervene with zinc in children at risk of zinc deficiency. Stable isotope techniques, linked with saturation response and compartmental modelling, also have the potential to assist in the continued search for simple markers of zinc status in health, malnutrition and disease.

  3. Influence of soil zinc concentrations on zinc sensitivity and functional diversity of microbial communities

    International Nuclear Information System (INIS)

    Lock, K.; Janssen, C.R.

    2005-01-01

    Pollution induced community tolerance (PICT) is based on the phenomenon that toxic effects reduce survival of the most sensitive organisms, thus increasing community tolerance. Community tolerance for a contaminant is thus a strong indicator for the presence of that contaminant at the level of adverse concentrations. Here we assessed PICT in 11 soils contaminated with zinc runoff from galvanised electricity pylons and 11 reference soils sampled at 10 m distance from these pylons. Using PICT, the influence of background concentration and bioavailability of zinc on zinc sensitivity and functional diversity of microbial communities was assessed. Zinc sensitivity of microbial communities decreased significantly with increasing zinc concentrations in pore water and calcium chloride extracted fraction while no significant relationship was found with total zinc concentration in the soil. It was also found that functional diversity of microbial communities decreased with increasing zinc concentrations, indicating that increased tolerance is indeed an undesirable phenomenon when environmental quality is considered. The hypothesis that zinc sensitivity of microbial communities is related to background zinc concentration in pore water could not be confirmed. - Zinc sensitivity of microbial communities and functional diversity decrease with increasing zinc concentration in the pore water

  4. The Potential for Zinc Stable Isotope Techniques and Modelling to Determine Optimal Zinc Supplementation

    Science.gov (United States)

    Tran, Cuong D.; Gopalsamy, Geetha L.; Mortimer, Elissa K.; Young, Graeme P.

    2015-01-01

    It is well recognised that zinc deficiency is a major global public health issue, particularly in young children in low-income countries with diarrhoea and environmental enteropathy. Zinc supplementation is regarded as a powerful tool to correct zinc deficiency as well as to treat a variety of physiologic and pathologic conditions. However, the dose and frequency of its use as well as the choice of zinc salt are not clearly defined regardless of whether it is used to treat a disease or correct a nutritional deficiency. We discuss the application of zinc stable isotope tracer techniques to assess zinc physiology, metabolism and homeostasis and how these can address knowledge gaps in zinc supplementation pharmacokinetics. This may help to resolve optimal dose, frequency, length of administration, timing of delivery to food intake and choice of zinc compound. It appears that long-term preventive supplementation can be administered much less frequently than daily but more research needs to be undertaken to better understand how best to intervene with zinc in children at risk of zinc deficiency. Stable isotope techniques, linked with saturation response and compartmental modelling, also have the potential to assist in the continued search for simple markers of zinc status in health, malnutrition and disease. PMID:26035248

  5. Impact of anode substrates on electrodeposited zinc over cycling in zinc-anode rechargeable alkaline batteries

    International Nuclear Information System (INIS)

    Wei, Xia; Desai, Divyaraj; Yadav, Gautam G.; Turney, Damon E.; Couzis, Alexander; Banerjee, Sanjoy

    2016-01-01

    Electrochemical behavior of Ag, Bi, Cu, Fe, Ni and Sn substrates on zinc deposition was evaluated over battery cycling by cyclic voltammetry and electrochemical impedance spectroscopy. The effect of Bi, Cu, Ni, and Sn substrates on zinc electrodeposition during battery cycling was investigated using scanning electron microscopy and X-ray diffraction. The corrosion behavior of each metal in 9 M KOH and the corrosion rates of zinc plated on each substrate were analyzed by Tafel extrapolation method from the potentiodynamic polarization curves and electrochemical impedance spectroscopy. Although the charge-transfer resistance (R_c_t) of zinc electrodeposition is lowest on Sn, Sn eventually corrodes on cycling in alkaline media. Use of Ni as a substrate causes zinc to deteriorate on account of rapid hydrogen evolution. Bi and Cu substrates are more suitable for use as current collectors in zinc-anode alkaline rechargeable batteries because of their low corrosion rate and compact zinc deposition over battery cycling.

  6. Serum zinc status of neonates with seizure

    Directory of Open Access Journals (Sweden)

    Olia Sharmeen

    2016-08-01

    Full Text Available Background: Seizure is a common neurological disorder in neonatal age group!. Primary metabolic derangement is one of the important reason behind this convulsion during this period. Among primary metabolic derangement hypoglycemia, is most common followed by bypocalcaemia, hypomagnesaemia, low zinc status etc. As causes of many cases of convul­sion remain unknown in neonate. Objectives: To see the zinc status in the sera of neonate with convulsion. So that if needed early intervention can be taken up and thereby prevent complications. Method: A total of 50 neonates (1-28 days who had convulsion with no apparent reasons of convulsion were enrolled as cases and 50 healthy age and sex matched neonates were enrolled as controls. After a quick clinical evaluation serum zinc status was estimated from venous blood by atomic absorption method in Chemistry Division, Atomic Energy Centre. Low zinc was considered if serum value was <0.7mg/L. Results: Among a total of 50 cases 6% had low zinc value & 2% of controls also had low zinc level. The mean serwu zinc level of cases and controls were 1.57±0.95 and 2.37±1.06 mmol/1 respectively (p<0.01. Conclusion: From the study it is seen that low zinc value is an important cause of neonatal seizure due to primary metabolic abnormalities. So early recognition and treatment could save these babies from long term neurological sequelies.

  7. Bioavailability of zinc to aerobic rice

    NARCIS (Netherlands)

    Gao, X.

    2007-01-01

    Keywords:Arbuscular mycorrhiza, Exudation, Oryza sativa , Rhizosphere, Rice, Soil, ZincZinc deficiency is a wide-spread constraint for crop production and human health. This thesis should contribute to alleviation of Zn deficiency problems and aimed at identifying soil

  8. 21 CFR 582.5994 - Zinc stearate.

    Science.gov (United States)

    2010-04-01

    ..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5994 Zinc stearate. (a) Product. Zinc stearate prepared from stearic acid free from chick-edema factor. (b) Conditions of use. This substance is generally recognized as safe when used in...

  9. Zinc dosing and glucose tolerance in humans

    International Nuclear Information System (INIS)

    Greenley, S.; Taylor, M.

    1986-01-01

    Animal data suggest the existence of a physiologic relationship between glucoregulatory hormones and zinc metabolism. In order to investigate this proposed relationship in humans, they examined the effect of moderately elevated plasma zinc levels on blood glucose clearance. Eight women (24-37 yrs) served as subjects for the study. Fasted volunteers were tested under two experimental conditions (a) ingestion of 50 g D-glucose (b) ingestion of 25 mg zinc followed 60 min later by ingestion of 50 g D-glucose. Five ml venous blood was drawn into trace-metal-free, fluoride-containing vacutainer tubes prior to and 15, 30, 45, 60, 90, and 120 min after glucose ingestion. Plasma was analyzed for glucose and zinc; glycemic responses were quantified by computing areas under the curves and times to peak concentration. Their human data indicate varied glycemic responses to the acute elevation of plasma zinc: 4 subjects showed little apparent effect; 3 subjects marginally increased either the area under the curve or time to peak and 1 subject (classified as suspect diabetic in the non-zinc condition) showed marked improvement in glycemic response following zinc ingestion. Their preliminary results suggest that blood glucose clearance may be affected in some individuals by the acute elevation of plasma zinc

  10. Solar cooking

    Science.gov (United States)

    Over two billion people face fuel wood shortages, causing tremendous personal and environmental stress. Over 4 million people die prematurely from indoor air pollution. Solar cooking can reduce fuel wood consumption and indoor air pollution. Solar cooking has been practiced and published since th...

  11. Solar Sprint

    Science.gov (United States)

    Tabor, Richard; Anderson, Stephen

    2007-01-01

    In the "Solar Sprint" activity, students design, test, and race a solar-powered car built with Legos. The use of ratios is incorporated to simulate the actual work of scientists and engineers. This method encourages fourth-grade students to think about multiple variables and stimulates their curiosity when an activity doesn't come out as…

  12. Effect of consuming zinc-fortified bread on serum zinc and iron status of zinc-deficient women: A double blind, randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Akbar Badii

    2012-01-01

    Full Text Available After iron deficiency, zinc deficiency is the major micronutrient deficiency in developing countries, and staple food fortification is an effective strategy to prevent and improve it among at-risk-populations. No action has been taken to reduce zinc deficiency via flour fortification so far in Iran, and little is known about the influence of zinc fortification of flour on serum zinc and the iron status, and also about the optimum and effective amount of zinc compound that is used in food fortification. The objective of this study is to evaluate the influence of consuming zinc-fortified breads on the zinc and iron status in the blood serum. In this study, three types of bread were prepared from non-fortified and fortified flours, with 50 and 100 ppm elemental zinc in the form of sulfate. Eighty zinc-deficient women aged 19 to 49 years were randomly assigned to three groups; The volunteers received, daily, (1 a non-fortified bread, (2 a high-zinc bread, and (3 a low-zinc bread for one month. Serum zinc and iron were measured by Atomic Absorption before and after the study. Results showed a significant increase in serum zinc and iron levels in all groups (p 0.05. Absorption of zinc and iron in the group that consumed high-zinc bread was significantly greater than that in the group that received low-zinc bread (p < 0.01. It was concluded that fortification of flour with 50-100 ppm zinc was an effective way to achieve adequate zinc intake and absorption in zinc-deficient people. It also appeared that consuming zinc-fortified bread improved iron absorption.

  13. Tracing of Zinc Nanocrystals in the Anterior Pituitary of Zinc-Deficient Wistar Rats.

    Science.gov (United States)

    Kuldeep, Anjana; Nair, Neena; Bedwal, Ranveer Singh

    2017-06-01

    The aim of this study was to trace zinc nanocrystals in the anterior pituitary of zinc-deficient Wistar rats by using autometallographic technique. Male Wistar rats (30-40 days of age, pre-pubertal period) of 40-50 g body weight were divided into the following: the ZC (zinc control) group-fed with 100 ppm zinc in diet, the ZD (zinc-deficient) group-fed with zinc-deficient (1.00 ppm) diet and the PF (pair-fed) group-received 100 ppm zinc in diet. The experiments were set for 2 and 4 weeks. Pituitary was removed and processed for the autometallographic technique. The control and pair-fed groups retained their normal morphological features. However, male Wistar rats fed on zinc-deficient diet for 2 and 4 weeks displayed a wide range of symptoms such as significant (P zinc nanocrystals in the nuclei. The present findings suggest that the dietary zinc deficiency causes decreased intensity of zinc nanocrystals localization and their distribution in the pituitary thereby contributing to the dysfunction of the pituitary of the male Wistar rats. The severity of zinc deficiency symptoms progressed after the second week of the experiment. Decreased intensity of zinc nanocrystals attenuates the pituitary function which would exert its affect on other endocrine organs impairing their functions indicating that the metabolic regulation of pituitary is mediated to a certain extent by zinc and/or hypothalamus-hypophysial system which also reflects its essentiality during the period of growth.

  14. Iron and zinc concentrations and 59Fe retention in developing fetuses of zinc-deficient rats

    International Nuclear Information System (INIS)

    Rogers, J.M.; Loennerdal, B.H.; Hurley, L.S.; Keen, C.L.

    1987-01-01

    Because disturbances in iron metabolism might contribute to the teratogenicity of zinc deficiency, we examined the effect of zinc deficiency on fetal iron accumulation and maternal and fetal retention of 59 Fe. Pregnant rats were fed from mating a purified diet containing 0.5, 4.5 or 100 micrograms Zn/g. Laparotomies were performed on d 12, 16, 19 and 21 of gestation. Maternal blood and concepti were analyzed for zinc and iron. Additional groups of dams fed 0.5 or 100 micrograms Zn/g diet were gavaged on d 19 with a diet containing 59 Fe. Six hours later maternal blood and tissues, fetuses and placentas were counted for 59 Fe. Maternal plasma zinc, but not iron, concentration was affected by zinc deficiency on d 12. Embryo zinc concentration on d 12 increased with increasing maternal dietary zinc, whereas iron concentration was not different among groups. On d 16-21 plasma iron was higher in dams fed 0.5 micrograms Zn/g diet than in those fed 4.5 or 100 micrograms/g, whereas plasma zinc was lower in dams fed 0.5 or 4.5 micrograms Zn/g than in those fed 100 micrograms Zn/g diet. On d 19 zinc concentration in fetuses from dams fed 0.5 micrograms/g zinc was not different from that of those fed 4.5 micrograms/g zinc, and iron concentration was higher in the 0.5 microgram Zn/g diet group. The increase in iron concentration in zinc-deficient fetuses thus occurs too late to be involved in major structural teratogenesis. Although whole blood concentration of 59 Fe was not different in zinc-deficient and control dams, zinc-deficient dams had more 59 Fe in the plasma fraction

  15. Diaroyl Tellurides: Synthesis, Structure and NBO Analysis of (2-MeOC6H4CO2Te – Comparison with Its Sulfur and Selenium Isologues. The First Observation of [MgBr][R(C=TeO] Salts

    Directory of Open Access Journals (Sweden)

    Fumio Ando

    2009-07-01

    Full Text Available A series of aromatic diacyl tellurides were prepared in moderate to good yields by the reactions of sodium orpotassium arenecarbotelluroates with acyl chlorides in acetonitrile. X-ray structure analyses and theoretical calculations of 2-methoxybenzoic anhydride and bis(2-methoxybenzoyl sulfide, selenide and telluride were carried out. The two 2-MeOC6H4CO moieties of bis(2-methoxybenzoyl telluride are nearly planar and the two methoxy oxygen atoms intramolecularly coordinate to the central tellurium atom from both side of C(11-Te(11-C(22 plane. In contrast, the oxygen and sulfur isologues (2-MeOC6H4CO2E (E = O, S, show that one of the two methoxy oxygen atoms contacts with the oxygen atom of the carbonyl group connected to the same benzene ring. The structure of di(2-methoxybenzoyl selenide which was obtained by MO calculation resembles that of tellurium isologues rather than the corresponding oxygen and sulfur isologues. The reactions of di(aroyl tellurides with Grignard reagents lead to the formation of tellurocarboxylato magnesium complexes [MgBr][R(C=TeO].

  16. Solar thermal

    International Nuclear Information System (INIS)

    Jones, J.

    2006-01-01

    While wind power is widely acknowledged as the most developed of the 'new' renewables, the number two technology, in terms of installed capacity functioning worldwide, is solar heating, or solar thermal. The author has investigated recent industry reports on how these markets are developing. The authors of an International Energy Agency (IEA) survey studied 41 countries in depth at the end of 2004, revealing that 141 million m 3 - corresponding to an installed capacity of 98.4 GWth - were installed in the sample countries (these nations represent 3.74 billion people, about 57% of the world's population). The installed capacity within the areas studied represents approximately 85%-90% of the solar thermal market worldwide. The use of solar heating varies greatly between countries - even close neighbours - and between economic regions. Its uptake often has more to do with policy than solar resource. There is also different uptake of technology. In China, Europe and Japan, plants with flat-plate and evacuated tube collectors are used, mainly to heat water and for space heating. Unglazed plastic collectors, used mainly for swimming pool heating, meanwhile, dominate the North American markets. Though the majority of solar heating installations today are installed on domestic rooftops, the larger-scale installations should not be overlooked. One important part of the market is the hotel sector - in particular hotels in locations that serve the seasonal summer holiday market, where solar is extremely effective. Likewise hospitals and residential homes, multi-family apartment blocks and sports centres are all good examples of places where solar thermal can deliver results. There are also a growing number of industrial applications, where solar thermal can meet the hot water needs (and possibly more) of a range of industries, such as food processing and agriculture. The ability of solar to provide a heat source for cooling is expected to become increasingly important as

  17. Solar thermal

    Energy Technology Data Exchange (ETDEWEB)

    Jones, J.

    2006-07-15

    While wind power is widely acknowledged as the most developed of the 'new' renewables, the number two technology, in terms of installed capacity functioning worldwide, is solar heating, or solar thermal. The author has investigated recent industry reports on how these markets are developing. The authors of an International Energy Agency (IEA) survey studied 41 countries in depth at the end of 2004, revealing that 141 million m{sup 3} - corresponding to an installed capacity of 98.4 GWth - were installed in the sample countries (these nations represent 3.74 billion people, about 57% of the world's population). The installed capacity within the areas studied represents approximately 85%-90% of the solar thermal market worldwide. The use of solar heating varies greatly between countries - even close neighbours - and between economic regions. Its uptake often has more to do with policy than solar resource. There is also different uptake of technology. In China, Europe and Japan, plants with flat-plate and evacuated tube collectors are used, mainly to heat water and for space heating. Unglazed plastic collectors, used mainly for swimming pool heating, meanwhile, dominate the North American markets. Though the majority of solar heating installations today are installed on domestic rooftops, the larger-scale installations should not be overlooked. One important part of the market is the hotel sector - in particular hotels in locations that serve the seasonal summer holiday market, where solar is extremely effective. Likewise hospitals and residential homes, multi-family apartment blocks and sports centres are all good examples of places where solar thermal can deliver results. There are also a growing number of industrial applications, where solar thermal can meet the hot water needs (and possibly more) of a range of industries, such as food processing and agriculture. The ability of solar to provide a heat source for cooling is expected to become

  18. Solar energy: photovoltaics

    International Nuclear Information System (INIS)

    Goetzberger, A.; Voss, B.; Knobloch, J.

    1994-01-01

    This textbooks covers the following topics: foundations of photovoltaics, solar energy, P-N junctions, physics of solar cells, high-efficiency solar cells, technology of Si solar cells, other solar cells, photovoltaic applications. (orig.)

  19. Electrochemical Reduction of Zinc Phosphate

    International Nuclear Information System (INIS)

    Kim, Chang Hwan; Lee, Jung Hyun; Shin, Woon Sup

    2010-01-01

    We demonstrated first that the electrochemical reduction of zinc phosphate in neutral phosphate buffer is possible and potentially applicable to bio-compatible rechargeable battery. The actual redox component is Zn(s)/Zn phosphate(s) and the future research about the control of crystal formation for the better cyclability is required. In lead-acid battery, the electrochemical redox reaction of Pb (s) /PbSO 4(s) is used by reducing Pb(II) and oxidizing Pb(0) in sulfate rich solution. Since both reduced form and oxidized form are insoluble, they cannot diffuse to the opposite electrodes and react. It is a very common strategy to make a stable battery electrode that a metal element is reduced and oxidized in solution containing an abundance of anion readily precipitating with the metal ion. For the application of this strategy to construction of rechargeable battery using bio-compatible electrode materials and electrolytes, the use of phosphate ion can be considered as anion readily precipitating with metal ions. If phosphate buffer with neutral pH is used as electrolyte, the better bio-compatibility will be achieved than most of rechargeable battery using strong acid, strong base or organic solvent as electrolyte solution. There are many metal ions readily precipitating with phos-phate ion, and zinc is one of them

  20. Solution growth, characterization and applications of zinc sulphide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Ndukwe, I C [School of Physical Sciences, Abia State University, Uturu, Abia State (Nigeria)

    1996-04-29

    Zinc sulphide (ZnS) thin films were successfully deposited on glass substrates under varying deposition conditions using the electroless or solution growth technique. The film properties investigated include their transmittance/reflectance/absorbance spectra, bandgap, optical constants, and thicknesses. Films grown under certain parametric conditions were found to exhibit high transmittance (64-98%), low absorbance, and low reflectance in the ultraviolet (uv)/visible/near infrared (nir) regions up to 1.00 {mu}m. Those obtained under other conditions exhibited high transmittance (78-98%) and low absorbance (0.01-0.1) in the uv/visible regions but low transmittance (30-37) and high absorbance (0.56) in the nir region. These characteristics revealed their suitability for various solar device applications. Bandgap range E{sub g}=3.7-3.8 eV and thickness range t=0.07 - 0.73 {mu}m were obtained.

  1. Solar powered vehicles: From dream to reality

    Energy Technology Data Exchange (ETDEWEB)

    1986-09-01

    The initiatives of the 'Schweizer Vereinigung fuer Sonnenenergie' (Swiss Association for Solar Energy) has added new impetus worldwide for the utilisation of solar energy. The Association organised the 'Tour de Sol', a race for vehicles propelled with the aid of solar energy. Solar vehicles with and without supplementary power, both standard production models and prototypes were eligible for the race. Before the start of the race, the solar-powered vehicles were 'filled up' with solar energy at a 'solar filling station'. The winner in the 'standard' section (a 2-seater small car for short distances) weighed in at 240 kg and attained a top speed of 100 km/h and a range of 150 km. The rear-wheel drive of this battery-powered vehicle was provided by 2 permanent magnet motors. A newly-developed nickel-zinc battery from the USA was available to power the twin engines. The energy requirement was the equivalent of less than 1 liter of petrol per 100 km.

  2. Solar Newsletter | Solar Research | NREL

    Science.gov (United States)

    more about work by this consortium, which crosses national laboratories, on new materials and designs information on NREL's research and development of solar technologies. To receive new issues by email prize, focused on solar energy technologies, and will release the prize rules and open registration

  3. Solar electricity and solar fuels

    Science.gov (United States)

    Spiers, David J.

    1989-04-01

    The nature of solar radiation and its variation with location is described. The distribution of energy in the solar spectrum places immediate limits on the theoretical efficiency of conversion processes, since practical absorbers cannot convert all wavelengths received to useful energy. The principles of solar energy conversion methods are described. Absorption of solar energy can give rise to direct electrical generation, heating, or chemical change. Electrical generation from sunlight can be achieved by photovoltaic systems directly or by thermal systems which use solar heat to drive a heat engine and generator. The technology used and under research for promising ways of producing electricity or fuel from solar energy is described. Photovoltaic technology is established today for remote area, small power applications, and photovoltaic module sales alone are over 100 million dollars per year at present. The photovoltaic market has grown steadily since the mid-1970's, as prices have fallen continuously. Future energy options are briefly described. The merits of a sustainable energy economy, based on renewable energy resources, including solar energy, are emphasized, as this seems to provide the only hope of eliminating the problems caused by the build-up of atmospheric carbon dioxide, acid rain pollution and nuclear waste disposal. There is no doubt that clean fuels which were derived from solar energy and either did not involve carbon dioxide and used atmospheric carbon dioxide as the source dioxide as the source of carbon would be a worthy ideal. Methods described could one day achieve this.

  4. Effects of zinc supplementation and zinc chelation on in vitro β-cell function in INS-1E cells

    DEFF Research Database (Denmark)

    Nygaard, Sanne Bjørn; Larsen, Agnete; Knuhtsen, Astrid

    2014-01-01

    BACKGROUND: Zinc is essential for the activities of pancreatic β-cells, especially insulin storage and secretion. Insulin secretion leads to co-release of zinc which contributes to the paracrine communication in the pancreatic islets. Zinc-transporting proteins (zinc-regulated transporter, iron......-regulated transporter-like proteins [ZIPs] and zinc transporters [ZnTs]) and metal-buffering proteins (metallothioneins, MTs) tightly regulate intracellular zinc homeostasis. The present study investigated how modulation of cellular zinc availability affects β-cell function using INS-1E cells. RESULTS: Using INS-1E...... cells, we found that zinc supplementation and zinc chelation had significant effects on insulin content and insulin secretion. Supplemental zinc within the physiological concentration range induced insulin secretion. Insulin content was reduced by zinc chelation with N,N,N',N-tektrakis(2-pyridylmethyl...

  5. Solar magnetohydrodynamics

    International Nuclear Information System (INIS)

    Priest, E.R.

    1982-01-01

    Solar MHD is an important tool for understanding many solar phenomena. It also plays a crucial role in explaining the behaviour of more general cosmical magnetic fields and plasmas, since the Sun provides a natural laboratory in which such behaviour may be studied. While terrestrial experiments are invaluable in demonstrating general plasma properties, conclusions from them cannot be applied uncritically to solar plasmas and have in the past given rise to misconceptions about solar magnetic field behaviour. Important differences between a laboratory plasma on Earth and the Sun include the nature of boundary conditions, the energy balance, the effect of gravity and the size of the magnetic Reynolds number (generally of order unity on the Earth and very much larger on the Sun). The overall structure of the book is as follows. It begins with two introductory chapters on solar observations and the MHD equations. Then the fundamentals of MHD are developed in chapters on magnetostatics, waves, shocks, and instabilities. Finally, the theory is applied to the solar phenomena of atmospheric heating, sunspots, dynamos, flares, prominences, and the solar wind. (Auth.)

  6. Serum zinc levels in gestational diabetes

    Directory of Open Access Journals (Sweden)

    Rahimi Sharbaf F

    2008-12-01

    Full Text Available "nBackground: Maternal zinc deficiency during pregnancy has been related to adverse pregnancy outcomes. Most studies in which pregnant women have been supplemented with zinc to examine its effects on the outcome of the pregnancy have been carried out in industrialized countries and the results have been inconclusive. It has been shown that women with gestational diabetes (GDM have lower serum zinc levels than healthy pregnant women, and higher rates of macrosomia. Zinc is required for normal glucose metabolism, and strengthens the insulin-induced transportation of glucose into cells by its effect on the insulin signaling pathway. The purpose of this study was to assess the serum zinc levels of GDM patients and evaluate the effect of zinc supplementation. "nMethods: In the first stage of this prospective controlled study, we enrolled 70 women who were 24-28 weeks pregnant at the Prenatal Care Center of Mirza Kochak Khan Hospital, Tehran, Iran. The serum zinc level of each subject was determined. In the second stage, among these 70 subjects, the diabetics receiving insulin were divided into two groups, only one of which received a zinc supplement and the other group was the control group. Birth weight of neonates and insulin dosages were recorded. "nResults: The mean serum zinc level in the GDM group was lower than that of the control group (94.83 vs. 103.49mg/dl, respectively and the mean birth weight of neonates from the GDM women who received the zinc supplement was lower than that of the control group (3849g vs. 4136g. The rate of macrosomia was lower in the zinc supplemented group (20% vs. 53%. The mean of increase of insulin after receiving the zinc supplement was lower (8.4u vs. 13.53. "nConclusion: Maternal insulin resistance is associated with the accumulation of maternal fat tissue during early stages of pregnancy and greater fetoplacental nutrient availability in later stages, when 70% of fetal growth occurs, resulting in macrosomia. In

  7. Effect of zinc gluconate, sage oil on inflammatory patterns and hyperglycemia in zinc deficient diabetic rats.

    Science.gov (United States)

    Elseweidy, Mohamed M; Ali, Abdel-Moniem A; Elabidine, Nabila Zein; Mursey, Nada M

    2017-11-01

    The relationship between zinc homeostasis and pancreatic function had been established. In this study we aimed firstly to configure the inflammatory pattern and hyperglycemia in zinc deficient diabetic rats. Secondly to illustrate the effect of two selected agents namely Zinc gluconate and sage oil (Salvia Officinalis, family Lamiaceae). Rats were fed on Zinc deficient diet, deionized water for 28days along with Zinc level check up at intervals to achieve zinc deficient state then rats were rendered diabetic through receiving one dose of alloxan monohydrate (120mg/kg) body weight, classified later into 5 subgroups. Treatment with sage oil (0.042mg/kg IP) and Zinc gluconate orally (150mg/kg) body weight daily for 8 weeks significantly reduced serum glucose, C-reactive protein (CRP), Tumor necrosis factor alpha (TNF- α), interleukins-6 1 β, inflammatory8 (IFN ȣ), pancreatic 1L1-β along with an increase in serum Zinc and pancreatic Zinc transporter 8 (ZNT8). Histopathological results of pancreatic tissues showed a good correlation with the biochemical findings. Both sage oil and zinc gluconate induced an improvement in the glycemic and inflammatory states. This may be of value like the therapeutic agent for diabetes. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  8. PREPARATION OF ZINC ENRICHED YEAST (SACCHAROMYCES CEREVISIAE BY CULTIVATION WITH DIFFERENT ZINC SALTS

    Directory of Open Access Journals (Sweden)

    Ľuboš Harangozo

    2012-02-01

    Full Text Available The yeast Saccharomyces cerevisiae is the best known microorganism and therefore widely used in many branches of industry. This study aims to investigate the accumulation of three inorganic zinc salts. Our research presents the ability of this yeast to absorb zinc from liquid medium and such enriched biomass use as a potential source of microelements in animal and/or human nutrition. It was found that the addition of different zinc forms, i.e. zinc nitrate, zinc sulphate and zinc chloride in fixed concentrations of 0, 25, 50 and 100 mg.100 ml-1 did not affect the amount of dry yeast biomass yielded, i.e. 1.0 – 1.2 g of yeast cells from 100 ml of cultivation medium, while higher presence of zinc solutions caused significantly lower yield of yeast biomass. The highest amount of zinc in yeast cells was achieved when added in the form of zinc nitrate in concentration of 200 mg.100 ml-1 YPD medium. The increment of intracellular zinc was up to 18.5 mg.g-1 of yeast biomass.

  9. [Advances in the research of zinc deficiency and zinc supplementation treatment in patients with severe burns].

    Science.gov (United States)

    Wang, X X; Zhang, M J; Li, X B

    2018-01-20

    Zinc is one of the essential trace elements in human body, which plays an important role in regulating acute inflammatory response, glucose metabolism, anti-oxidation, immune and gastrointestinal function of patients with severe burns. Patients with severe burns may suffer from zinc deficiency because of insufficient amount of zinc intake from the diet and a large amount of zinc lose through wounds and urine. Zinc deficiency may affect their wound healing process and prognosis. This article reviews the characteristics of zinc metabolism in patients with severe burns through dynamic monitoring the plasma and urinary concentration of zinc. An adequate dosage of zinc supplemented to patients with severe burns by an appropriate method can increase the level of zinc in plasma and skin tissue and improve wound healing, as well as reduce the infection rates and mortality. At the same time, it is important to observe the symptoms and signs of nausea, dizziness, leukopenia and arrhythmia in patients with severe burns after supplementing excessive zinc.

  10. Solar collectors

    Energy Technology Data Exchange (ETDEWEB)

    Hullmann, H; Schmidt, B [Technische Univ. Hannover (Germany, F.R.). Inst. fuer Industrialisierung des Bauens

    1976-01-01

    The utilisation possibilities of solar energy for the energy supplying of buildings are becoming increasingly more significant. Solar research at the moment aims predominantly with a high level of efficiency and therefore making accessible a significant range of applications for solar technology. Parallel to this are attempts to effect the saving of energy, be it in the demand for energy-saving constructions or in the increasing development and application of rational energy utilisation by technologists. The most important point of these activities at the moment, is still technological methods.

  11. Solar neutrinos

    International Nuclear Information System (INIS)

    Schatzman, E.

    1983-01-01

    The solar energy is produced by a series of nuclear reactions taking place in the deep interior of the sun. Some of these reactions produce neutrinos which may be detected, the proper detection system being available. The results of the Davis experiment (with 37 Cl) are given, showing a deficiency in the solar neutrino flux. The relevant explanation is either a property of the neutrino or an important change in the physics of the solar models. The prospect of a new experiment (with 71 Ga) is important as it will decide which of the two explanations is correct [fr

  12. Concentrating Solar Power Projects - Planta Solar 20 | Concentrating Solar

    Science.gov (United States)

    Power | NREL 20 This page provides information on Planta Solar 20, a concentrating solar power Solar's Planta Solar 20 (PS20) is a 20-megawatt power tower plant being constructed next to the PS10 tower and increasing incident solar radiation capture will increase net electrical power output by 10

  13. Zinc-Laccase Biofuel Cell

    Directory of Open Access Journals (Sweden)

    Abdul Aziz Ahmad

    2011-12-01

    Full Text Available A zinc-laccase biofuel cell adapting the zinc-air cell design features is investigated. A simple cell design configuration is employed: a membraneless single chamber and a freely suspended laccase in a quasi-neutral buffer electrolyte. The cell is characterised according to its open-circuit voltage, polarization profile, power density plot and discharge capacity at constant current. The biocatalytic role of laccase is evident from the polarization profile and power output plot. Performance comparison between a single chamber and dual chamber cell design is also presented. The biofuel cell possessed an open-circuit voltage of 1.2 V and delivered a maximum power density of 0.9 mW/cm2 at current density of 2.5 mA/cm2. These characteristics are comparable to biofuel cell utilising a much more complex system design.KEY WORDS (keyword:  Biofuel cell, Bioelectrochemical cell, Zinc anode, Laccase and Oxidoreductase.ABSTRAK: Sel bio-bahan api zink-laccase dengan adaptasi daripada ciri-ciri rekabentuk sel zink-udara telah dikaji. Sel dengan konfigurasi rekabentuk yang mudah digunapakai: ruangan tunggal tanpa membran dan laccase diampaikan secara bebas di dalam elektrolit pemampan quasi-neutral. Sel dicirikan berdasarkan voltan litar terbuka, profil polarisasi, plot ketumpatan kuasa dan kapasiti discas pada arus malar. Peranan laccase sebagai bio-pemangkin adalah amat ketara daripada profil polarisasi dan plot ketumpatan kuasa. Perbandingan prestasi di antara sel dengan rekabentuk ruangan tunggal and dwi-ruangan turut diketengahkan. Seperti dijangkakan, sel dengan rekabentuk ruangan tunggal menunjukkan kuasa keluaran yang lebih rendah jika dibandingkan dengan rekabentuk dwi-ruangan kemungkinan disebabkan fenomena cas bocor. Sel bio-bahan api ini mempunyai voltan litar terbuka 1.2 V dan memberikan ketumpatan kuasa maksima 0.9 mW/cm2 pada ketumpatan arus 2.5 mA/cm2. Ciri-ciri ini adalah sebanding dengan sel bio-bahan api yang menggunapakai rekabentuk sel

  14. Growth and Characterization of (211)B Cadmium Telluride Buffer Layer Grown by Metal-organic Vapor Phase Epitaxy on Nanopatterned Silicon for Mercury Cadmium Telluride Based Infrared Detector Applications

    Science.gov (United States)

    Shintri, Shashidhar S.

    Mercury cadmium telluride (MCT or Hg1-xCdxTe) grown by molecular beam epitaxy (MBE) is presently the material of choice for fabricating infrared (IR) detectors used in night vision based military applications. The focus of MCT epitaxy has gradually shifted since the last decade to using Si as the starting substrate since it offers several advantages. But the ˜19 % lattice mismatch between MCT and Si generates lots of crystal defects some of which degrade the performance of MCT devices. Hence thick CdTe films are used as buffer layers on Si to accommodate the defects. However, growth of high quality single crystal CdTe on Si is challenging and to date, the best MBE CdTe/Si reportedly has defects in the mid-105 cm -2 range. There is a critical need to reduce the defect levels by at least another order of magnitude, which is the main motivation behind the present work. The use of alternate growth technique called metal-organic vapor phase epitaxy (MOVPE) offers some advantages over MBE and in this work MOVPE has been employed to grow the various epitaxial films. In the first part of this work, conditions for obtaining high quality (211)B CdTe epitaxy on (211)Si were achieved, which also involved studying the effect of having additional intermediate buffer layers such as Ge and ZnTe and incorporation of in-situ thermal cyclic annealing (TCA) to reduce the dislocation density. A critical problem of Si cross-contamination due to 'memory effect' of different reactant species was minimized by introducing tertiarybutylArsine (TBAs) which resulted in As-passivation of (211)Si. The best 8-10 µm thick CdTe films on blanket (non-patterned) Si had dislocations around 3×105 cm-2, which are the best reported by MOVPE till date and comparable to the highest quality films available by MBE. In the second part of the work, nanopatterned (211)Si was used to study the effect of patterning on the crystal quality of epitaxial CdTe. In one such study, patterning of ˜20 nm holes in SiO2

  15. ZINC MITIGATION INTERIM REPORT - THERMODYNAMIC STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Korinko, P.

    2010-12-17

    An experimental program was initiated in order to develop and validate conditions that will effectively trap Zn vapors that are released during extraction. The proposed work is broken down into three tasks. The first task is to determine the effectiveness of various pore sizes of filter elements. The second task is to determine the effect of filter temperature on zinc vapor deposition. The final task is to determine whether the zinc vapors can be chemically bound. The approach for chemically binding the zinc vapors has two subtasks, the first is a review of literature and thermodynamic calculations and the second is an experimental approach using the best candidates. This report details the results of the thermodynamic calculations to determine feasibility of chemically binding the zinc vapors within the furnace module, specifically the lithium trap (1). A review of phase diagrams, literature, and thermodynamic calculations was conducted to determine if there are suitable materials to capture zinc vapor within the lithium trap of the extraction basket. While numerous elements exist that form compounds with zinc, many of these also form compounds with hydrogen or the water that is present in the TPBARs. This relatively comprehensive review of available data indicates that elemental cobalt and copper and molybdenum trioxide (MoO3) may have the requisite properties to capture zinc and yet not be adversely affected by the extraction gases and should be considered for testing.

  16. Zinc Binding by Lactic Acid Bacteria

    Directory of Open Access Journals (Sweden)

    Jasna Mrvčić

    2009-01-01

    Full Text Available Zinc is an essential trace element in all organisms. A common method for the prevention of zinc deficiency is pharmacological supplementation, especially in a highly available form of a metalloprotein complex. The potential of different microbes to bind essential and toxic heavy metals has recently been recognized. In this work, biosorption of zinc by lactic acid bacteria (LAB has been investigated. Specific LAB were assessed for their ability to bind zinc from a water solution. Significant amount of zinc ions was bound, and this binding was found to be LAB species-specific. Differences among the species in binding performance at a concentration range between 10–90 mg/L were evaluated with Langmuir model for biosorption. Binding of zinc was a fast process, strongly influenced by ionic strength, pH, biomass concentration, and temperature. The most effective metal-binding LAB species was Leuconostoc mesenteroides (27.10 mg of Zn2+ per gram of dry mass bound at pH=5 and 32 °C, during 24 h. FT-IR spectroscopy analysis and electron microscopy demonstrated that passive adsorption and active uptake of the zinc ions were involved.

  17. Pseudomonas aeruginosa Trent and zinc homeostasis.

    Science.gov (United States)

    Davies, Corey B; Harrison, Mark D; Huygens, Flavia

    2017-09-01

    Pseudomonas aeruginosa is a Gram-negative pathogen and the major cause of mortality in patients with cystic fibrosis. The mechanisms that P. aeruginosa strains use to regulate intracellular zinc have an effect on infection, antibiotic resistance and the propensity to form biofilms. However, zinc homeostasis in P. aeruginosa strains of variable infectivity has not been compared. In this study, zinc homeostasis in P. aeruginosa Trent, a highly infectious clinical strain, was compared to that of a laboratory P. aeruginosa strain, ATCC27853. Trent was able to tolerate higher concentrations of additional zinc in rich media than ATCC27853. Further, pre-adaptation to additional zinc enhanced the growth of Trent at non-inhibitory concentrations but the impact of pre-adaption on the growth of ATCC27853 under the same conditions was minimal. The results establish clear differences in zinc-induced responses in Trent and ATCC27853, and how zinc homeostasis can be a promising target for the development of novel antimicrobial strategies for P. aeruginosa infection in cystic fibrosis patients. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Zinc-enriched boutons in rat spinal cord

    DEFF Research Database (Denmark)

    Schrøder, H D; Danscher, G; Jo, S M

    2000-01-01

    The rat spinal cord reveals a complex pattern of zinc-enriched (ZEN) boutons. As a result of in vivo exposure to selenide ions, nanosized clusters of zinc selenide are created in places where zinc ions are present, including the zinc-containing synaptic vesicles of ZEN boutons. The clusters can...

  19. Zinc, nitrogen and salinity interaction on agronomic traits and some ...

    African Journals Online (AJOL)

    use

    2011-11-23

    Nov 23, 2011 ... percentage decreased due to nitrogen, zinc and salinity in the first year but .... Analysis of variance on canola traits affected by nitrogen, zinc and salinity at ...... a result less of the latter are available for fat synthesis ... Na+ and Cl- in plant tissues, effects of nitrogen and zinc ... Zinc alleviates cadmium-induced.

  20. Zinc electrode shape change II. Process and mechanism

    NARCIS (Netherlands)

    Einerhand, R.E.F.; Visscher, W.; de Goeij, J.J.M.; Barendrecht, E.

    1991-01-01

    The process and mechanism of zinc electrode shape change is investigated with the radiotracer technique. It is shownthat during repeated cycling of the nickel oxide/zinc battery zinc material is transported over the zinc electrode via the battery electrolyte. During charge as well as during

  1. Polycrystalline Thin-Film Cadmium Telluride Solar Cells Fabricated by Electrodeposition; Final Technical Report, 20 March 1995-15 June 1998

    Energy Technology Data Exchange (ETDEWEB)

    Trefny, J. U.; Mao, D.; Kaydanov, V.; Ohno, T. R.; Williamson, D. L.; Collins, R.; Furtak, T. E.

    1999-01-27

    This report summarizes work performed by the Colorado School of Mines Department of Physics under this subcontract. Based on the studies conducted, researchers increased the efficiency of the cells with electrodeposited CdTe and CBD CdS by 3% on average ({approx}30 relative %). The improvement came from 1. Optimization of CdS initial thickness taking into account CdS consumption of CdTe during the CdTe/CdS post-deposition treatment; optimization of CdS post-deposition treatment with CdCl2 aimed at prevention of Te diffusion into CdS and improvement of the CdS film morphology and electronic properties. That led to a considerable increase in short circuit current, by 13% on average. 2. Optimization of CdTe thickness and post-deposition treatment which led to a significant increase in Voc, by {approx}70 mV. The highest Voc obtained exceeded 800 mV. 3. Development of a ZnTe:Cu/Metal back contact processing procedure that included selection of optimal Cu content, deposition regime and post-deposition treatment conditions. As a result, back contact resistance as low as 0.1W-cm2 was obtained. The cell stability was measured on exposure to accelerated stress conditions. Preliminary studies of some new approaches to improvement of CdS/CdTe structure were conducted.

  2. Implication of zinc excess on soil health.

    Science.gov (United States)

    Wyszkowska, Jadwiga; Boros-Lajszner, Edyta; Borowik, Agata; Baćmaga, Małgorzata; Kucharski, Jan; Tomkiel, Monika

    2016-01-01

    This study was undertaken to evaluate zinc's influence on the resistance of organotrophic bacteria, actinomyces, fungi, dehydrogenases, catalase and urease. The experiment was conducted in a greenhouse of the University of Warmia and Mazury (UWM) in Olsztyn, Poland. Plastic pots were filled with 3 kg of sandy loam with pHKCl - 7.0 each. The experimental variables were: zinc applied to soil at six doses: 100, 300, 600, 1,200, 2,400 and 4,800 mg of Zn(2+) kg(-1) in the form of ZnCl2 (zinc chloride), and species of plant: oat (Avena sativa L.) cv. Chwat and white mustard (Sinapis alba) cv. Rota. Soil without the addition of zinc served as the control. During the growing season, soil samples were subjected to microbiological analyses on experimental days 25 and 50 to determine the abundance of organotrophic bacteria, actinomyces and fungi, and the activity of dehydrogenases, catalase and urease, which provided a basis for determining the soil resistance index (RS). The physicochemical properties of soil were determined after harvest. The results of this study indicate that excessive concentrations of zinc have an adverse impact on microbial growth and the activity of soil enzymes. The resistance of organotrophic bacteria, actinomyces, fungi, dehydrogenases, catalase and urease decreased with an increase in the degree of soil contamination with zinc. Dehydrogenases were most sensitive and urease was least sensitive to soil contamination with zinc. Zinc also exerted an adverse influence on the physicochemical properties of soil and plant development. The growth of oat and white mustard plants was almost completely inhibited in response to the highest zinc doses of 2,400 and 4,800 mg Zn(2+) kg(-1).

  3. Solar prominences

    CERN Document Server

    Engvold, Oddbjørn

    2015-01-01

    This volume presents the latest research results on solar prominences, including new developments on e.g. chirality, fine structure, magnetism, diagnostic tools and relevant solar plasma physics. In 1875 solar prominences, as seen out of the solar limb, were described by P.A. Secchi in his book Le Soleil as "gigantic pink or peach-flower coloured flames". The development of spectroscopy, coronagraphy and polarimetry brought tremendous observational advances in the twentieth century. The authors present and discuss exciting new challenges (resulting from observations made by space and ground-based telescopes in the 1990s and the first decade of the 21st century) concerning the diagnostics of prominences, their formation, their life time and their eruption along with their impact in the heliosphere (including the Earth). The book starts with a general introduction of the prominence “object” with some historical background on observations and instrumentation. In the next chapter, the various forms of promine...

  4. Solar chulha

    Energy Technology Data Exchange (ETDEWEB)

    Jadhao, P. H. [Department of Physics J.D. Institute of Engg. & Tech. Yavatmal (India); Patrikar, S. R. [Department of Physics VNIT, Nagpur (India)

    2016-05-06

    The main goal of the proposed system is to transfer energy from sun to the cooking load that is located in the kitchen. The energy is first collected by the solar collector lens system and two curve bars of same radius of curvature are mounted parallel and adjacent to each other at different height the solar collector is clamed on this two bars such that solar collector is exactly perpendicular to sunlight. The topology includes an additional feature which is window in the wall through which the beam is collimated is directed in the of kitchen. The solar energy that is collected is directed by the mirror system into the kitchen, where it is redirected to cooking platform located in the kitchen. The special feature in this system full Indian meal can be made since cooking platform is indoors.

  5. Solar Radio

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Scientists monitor the structure of the solar corona, the outer most regions of the Sun's atmosphere, using radio waves (100?s of MHz to 10?s of GHz). Variations in...

  6. Solar Energy

    Science.gov (United States)

    Building Design and Construction, 1977

    1977-01-01

    Describes 21 completed projects now using solar energy for heating, cooling, or electricity. Included are elementary schools in Atlanta and San Diego, a technical school in Detroit, and Trinity University in San Antonio, Texas. (MLF)

  7. Study of iron-zinc catalysts by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Arriola, S.H.

    1990-01-01

    The Moessbauer parameters were determined on a series of catalyst mixtures of iron and zinc oxides with variable quantities of zinc. A change in the crystal structure of the iron oxide when introducing zinc into the samples was observed. The corundum structure of the α-Fe 2 O 3 phase was transformed into the spinel type of zinc ferrite when zinc oxide was present in any quantity. A strong electronic interaction between the zinc ferrite and the zinc oxide present in excess was evident. The catalysts were analyzed using x-ray fluorescence and x-ray diffraction methods. (author) 10 refs.; 4 figs.; 2 tabs

  8. Electrochemical energy storage systems for solar thermal applications

    Science.gov (United States)

    Krauthamer, S.; Frank, H.

    1980-01-01

    Existing and advanced electrochemical storage and inversion/conversion systems that may be used with terrestrial solar-thermal power systems are evaluated. The status, cost and performance of existing storage systems are assessed, and the cost, performance, and availability of advanced systems are projected. A prime consideration is the cost of delivered energy from plants utilizing electrochemical storage. Results indicate that the five most attractive electrochemical storage systems are the: iron-chromium redox (NASA LeRC), zinc-bromine (Exxon), sodium-sulfur (Ford), sodium-sulfur (Dow), and zinc-chlorine (EDA).

  9. The zinc dyshomeostasis hypothesis of Alzheimer's disease.

    Directory of Open Access Journals (Sweden)

    Travis J A Craddock

    Full Text Available Alzheimer's disease (AD is the most common form of dementia in the elderly. Hallmark AD neuropathology includes extracellular amyloid plaques composed largely of the amyloid-β protein (Aβ, intracellular neurofibrillary tangles (NFTs composed of hyper-phosphorylated microtubule-associated protein tau (MAP-tau, and microtubule destabilization. Early-onset autosomal dominant AD genes are associated with excessive Aβ accumulation, however cognitive impairment best correlates with NFTs and disrupted microtubules. The mechanisms linking Aβ and NFT pathologies in AD are unknown. Here, we propose that sequestration of zinc by Aβ-amyloid deposits (Aβ oligomers and plaques not only drives Aβ aggregation, but also disrupts zinc homeostasis in zinc-enriched brain regions important for memory and vulnerable to AD pathology, resulting in intra-neuronal zinc levels, which are either too low, or excessively high. To evaluate this hypothesis, we 1 used molecular modeling of zinc binding to the microtubule component protein tubulin, identifying specific, high-affinity zinc binding sites that influence side-to-side tubulin interaction, the sensitive link in microtubule polymerization and stability. We also 2 performed kinetic modeling showing zinc distribution in extra-neuronal Aβ deposits can reduce intra-neuronal zinc binding to microtubules, destabilizing microtubules. Finally, we 3 used metallomic imaging mass spectrometry (MIMS to show anatomically-localized and age-dependent zinc dyshomeostasis in specific brain regions of Tg2576 transgenic, mice, a model for AD. We found excess zinc in brain regions associated with memory processing and NFT pathology. Overall, we present a theoretical framework and support for a new theory of AD linking extra-neuronal Aβ amyloid to intra-neuronal NFTs and cognitive dysfunction. The connection, we propose, is based on β-amyloid-induced alterations in zinc ion concentration inside neurons affecting stability of

  10. The zinc dyshomeostasis hypothesis of Alzheimer's disease.

    Science.gov (United States)

    Craddock, Travis J A; Tuszynski, Jack A; Chopra, Deepak; Casey, Noel; Goldstein, Lee E; Hameroff, Stuart R; Tanzi, Rudolph E

    2012-01-01

    Alzheimer's disease (AD) is the most common form of dementia in the elderly. Hallmark AD neuropathology includes extracellular amyloid plaques composed largely of the amyloid-β protein (Aβ), intracellular neurofibrillary tangles (NFTs) composed of hyper-phosphorylated microtubule-associated protein tau (MAP-tau), and microtubule destabilization. Early-onset autosomal dominant AD genes are associated with excessive Aβ accumulation, however cognitive impairment best correlates with NFTs and disrupted microtubules. The mechanisms linking Aβ and NFT pathologies in AD are unknown. Here, we propose that sequestration of zinc by Aβ-amyloid deposits (Aβ oligomers and plaques) not only drives Aβ aggregation, but also disrupts zinc homeostasis in zinc-enriched brain regions important for memory and vulnerable to AD pathology, resulting in intra-neuronal zinc levels, which are either too low, or excessively high. To evaluate this hypothesis, we 1) used molecular modeling of zinc binding to the microtubule component protein tubulin, identifying specific, high-affinity zinc binding sites that influence side-to-side tubulin interaction, the sensitive link in microtubule polymerization and stability. We also 2) performed kinetic modeling showing zinc distribution in extra-neuronal Aβ deposits can reduce intra-neuronal zinc binding to microtubules, destabilizing microtubules. Finally, we 3) used metallomic imaging mass spectrometry (MIMS) to show anatomically-localized and age-dependent zinc dyshomeostasis in specific brain regions of Tg2576 transgenic, mice, a model for AD. We found excess zinc in brain regions associated with memory processing and NFT pathology. Overall, we present a theoretical framework and support for a new theory of AD linking extra-neuronal Aβ amyloid to intra-neuronal NFTs and cognitive dysfunction. The connection, we propose, is based on β-amyloid-induced alterations in zinc ion concentration inside neurons affecting stability of polymerized

  11. Sensores de zinc para aplicaciones en neurociencias

    OpenAIRE

    Estela Falla, Aldo David; Estela Falla, Aldo David; Estela Falla, Aldo David

    2011-01-01

    En los últimos años, los estudios realizados con respecto a la química involucrada en los procesos neurológicos han logrado dar una idea de la importancia del zinc en las funciones nerviosas, así como también en el estudio de enfermedades neurodegenerativas tales como la Enfermedad de Alzheimer. A nivel biológico, el zinc tiene representantes en los seis grupos de enzimas que existen, lo cual demuestra su gran importancia en los sistemas biológicos. En estas enzimas, el zinc como ion metál...

  12. Zinc Deficiency in Humans and its Amelioration

    OpenAIRE

    Yashbir Singh Shivay

    2015-01-01

    Zinc (Zn) deficiency in humans has recently received considerable attention. Global mortality in children under 5 years of age in 2004 due to Zn deficiency was estimated at 4,53,207 as against 6,66,771 for vitamin A deficiency; 20,854 for iron deficiency and 3,619 for iodine deficiency. In humans 2800-3000 proteins contain Zn prosthetic group and Zn is an integral component of zinc finger prints that regulate DNA transcription. Zinc is a Type-2 nutrient, which means that its concentration in ...

  13. Spectrophotometric determination of zinc in impure solutions

    International Nuclear Information System (INIS)

    Rodriguez Hernandez, B.; Reyes Tamaral, A.

    1972-01-01

    A dithizone colorimetric method is described for determining zinc concentrations of 0.001 to 5 g/l in aqueous solutions from Rio Tinto Mines, containing copper, iron and other impurities. Citrate, cyanide and bis-2hydroxyethyl)-dithiocarbamate are added to the aqueous sample of masking several metals, and zinc is extracted at pH 5 with a solution of dithizone in carbon tetrachloride. Excess of dithizone is removed with sodium sulphide, and optical density of zinc dithionate in organic solution is measured at 5.35 nm. Calibration curves obey Beer's law up to 0.5 micro Zn/ml. (Author) 5 refs

  14. Zinc oxide nanoparticles for water disinfection

    Directory of Open Access Journals (Sweden)

    Emelita Asuncion S. Dimapilis

    2018-03-01

    Full Text Available The world faces a growing challenge for adequate clean water due to threats coming from increasing demand and decreasing supply. Although there are existing technologies for water disinfection, their limitations, particularly the formation of disinfection-by-products, have led to researches on alternative methods. Zinc oxide, an essential chemical in the rubber and pharmaceutical industries, has attracted interest as antimicrobial agent. In nanoscale, zinc oxide has shown antimicrobial properties which make its potential great for various applications. This review discusses the synthesis of zinc oxide with focus on precipitation method, its antimicrobial property and the factors affecting it, disinfection mechanisms, and the potential application to water disinfection.

  15. Solar Pump

    Science.gov (United States)

    Pique, Charles

    1987-01-01

    Proposed pump moves liquid by action of bubbles formed by heat of sun. Tube of liquid having boiling point of 100 to 200 degrees F placed at focal axis of cylindrical reflector. Concentrated sunlight boils liquid at focus, and bubbles of vapor rise in tube, carrying liquid along with them. Pressure difference in hot tube sufficient to produce flow in large loop. Used with conventional flat solar heating panel in completely solar-powered heat-storage system.

  16. Clinical Aspects of Trace Elements: Zinc in Human Nutrition – Zinc Deficiency and Toxicity

    Directory of Open Access Journals (Sweden)

    Michelle M Pluhator

    1996-01-01

    Full Text Available Available evidence suggests that trace elements, such as zinc, once thought to have no nutritional relevance, are possibly deficient in large sections of the human population. Conditioned deficiencies have been reported to result from malabsorption syndromes, acrodermatitis enteropathica, alcoholism, gastrointestinal disease, thermal injury, chronic diseases (eg, diabetes, sickle cell anemia, and in total parenteral nutrition therapy. Awareness that patients with these problems are at risk has led health professionals to focus increasingly on the importance of zinc therapy in the prevention and treatment of deficiency. More recently zinc toxicity and its role in human nutrition and well-being have come under investigation. Reports have focused on the role of zinc toxicity in causes of copper deficiency, changes in the immune system and alterations in blood lipids. As the numerous challenges presented by the study of zinc in human nutrition are met, more appropriate recommendations for dietary and therapeutic zinc intake are being made.

  17. Solar Schematic

    Science.gov (United States)

    1979-01-01

    The home shown at right is specially designed to accommodate solar heating units; it has roof planes in four directions, allowing placement of solar collectors for best exposure to the sun. Plans (bottom) and complete working blueprints for the solar-heated house are being marketed by Home Building Plan Service, Portland, Oregon. The company also offers an inexpensive schematic (center) showing how a homeowner only moderately skilled in the use of tools can build his own solar energy system, applicable to new or existing structures. The schematic is based upon the design of a low-cost solar home heating system built and tested by NASA's Langley Research Center; used to supplement a warm-air heating system, it can save the homeowner about 40 percent of his annual heating bill for a modest investment in materials and components. Home Building Plan Service saved considerable research time by obtaining a NASA technical report which details the Langley work. The resulting schematic includes construction plans and simplified explanations of solar heat collection, collectors and other components, passive heat factors, domestic hot water supply and how to work with local heating engineers.

  18. Intestinal absorption and excretion of zinc in streptozotocin-diabetic rats as affected by dietary zinc and protein

    International Nuclear Information System (INIS)

    Johnson, W.T.; Canfield, W.K.

    1985-01-01

    65 Zn was used to examine the effects of dietary zinc and protein on true zinc absorption and intestinal excretion of endogenous zinc by an isotope dilution technique in streptozotocin-diabetic and control rats. Four groups each of diabetic and control rats were fed diets containing 20 ppm Zn, 20% egg white protein (HMHP); 20 ppm Zn, 10% egg white protein (HMLP); 10 ppm Zn, 20% egg white protein (LMHP); and 10 ppm Zn, 10% egg white protein (LMLP). Measurement of zinc balance was begun 9 d after an i.m. injection of 65 Zn. True zinc absorption and the contribution of endogenous zinc to fecal zinc excretion were calculated from the isotopically labeled and unlabeled zinc in the feces, duodenum and kidney. Results from the isotope dilution study indicated that diabetic rats, but not control rats, absorbed more zinc from 20 ppm zinc diets than from 10ppm zinc diets and that all rats absorbed more zinc from 20% protein diets than from 10% protein diets. Furthermore, all rats excreted more endogenous zinc from their intestines when dietary zinc and protein levels resulted in greater zinc absorption. In diabetic and control rats, consuming equivalent amounts of zinc, the amount of zinc absorbed was not significantly different, but the amount of zinc excreted by the intestine was less in the diabetic rats. Decreased intestinal excretion of endogenous zinc may be a homeostatic response to the increased urinary excretion of endogenous zinc in the diabetic rats and may also lead to the elevated zinc concentrations observed in some organs of the diabetic rats

  19. Nanolithography on mercury telluride

    International Nuclear Information System (INIS)

    Muehlbauer, Mathias Josef

    2015-01-01

    Topological insulators belong to a new quantum state of matter that is currently one of the most recognized research fields in condensed matter physics. Strained bulk HgTe and HgTe/HgCdTe quantum well structures are currently one of few topological insulator material systems suitable to be studied in transport experiments. In addition HgTe quantum wells provide excellent requirements for the conduction of spintronic experiments. A fundamental requirement for most experiments, however, is to reliably pattern these heterostructures into advanced nano-devices. Nano-lithography on this material system proves to be challenging because of inherent temperature limitations, its high reactivity with various metals and due to its properties as a topological insulator. The current work gives an insight into why many established semiconductor lithography processes cannot be easily transferred to HgTe while providing alternative solutions. The presented developments include novel ohmic contacts, the prevention of metal sidewalls and redeposition fences in combination with low temperature (80 C) lithography and an adapted hardmask lithography process utilizing a sacrificial layer. In addition we demonstrate high resolution low energy (2.5 kV) electron beam lithography and present an alternative airbridge gating technique. The feasibility of nano-structures on HgTe quantum wells is exemplarily verified in two separate transport experiments. We are first to realize physically etched quantum point contacts in HgTe/HgCdTe high mobility 2DEGs and to prove their controllability via external top-gate electrodes. So far quantum point contacts have not been reported in TI materials. However, these constrictions are part of many proposals to probe the nature of the helical quantum spin Hall edge channels and are suggested as injector and detector devices for spin polarized currents. To confirm their functionality we performed four-terminal measurements of the point contact conductance as a function of external gate voltage. Our measurements clearly exhibit quantized conductance steps in 2e"2/h, which is a fundamental characteristic of quantum point contacts. Furthermore we conducted measurements on the formation and control of collimated electron beams, a key feature to realize an all electrical spin-optic device. In a second study several of the newly developed lithography techniques were implemented to produce arrays of nano-wires on inverted and non-inverted HgTe quantum well samples. These devices were used in order to probe and compare the weak antilocalization (WAL) in these structures as a function of magnetic field and temperature. Our measurements reveal that the WAL is almost an order of magnitude larger in inverted samples. This observation is attributed to the Dirac-like dispersion of the energy bands in HgTe quantum wells. The described lithography has already been successfully implemented and adapted in several published studies. All processes have been optimized to guarantee a minimum effect on the heterostructure's properties and the sample surface, which is especially important for probing the topological surface states of strained HgTe bulk layers. Our developments therefore serve as a base for continuous progress to further establish HgTe as a topological insulator and give access to new experiments.

  20. Prevalence of zinc deficiency among primary school children in a ...

    African Journals Online (AJOL)

    Few zinc-rich sources appeared in the diet that was predominantly plant-based. Mean dietary zinc intake was 4.6±2.2 mg/day. The mean value of serum zinc was 66.4±21.5 μg/dL, with 46% of the children having values less than the 70 μg/dL cutoff. The findings indicate a high risk of zinc deficiency and suboptimal zinc ...

  1. Potential ecological risk assessment and predicting zinc accumulation in soils

    OpenAIRE

    Baran, Agnieszka; Wieczorek, Jerzy; Mazurek, Ryszard; Urbański, Krzysztof; Klimkowicz-Pawlas, Agnieszka

    2017-01-01

    The aims of this study were to investigate zinc content in the studied soils; evaluate the efficiency of geostatistics in presenting spatial variability of zinc in the soils; assess bioavailable forms of zinc in the soils and to assess soil–zinc binding ability; and to estimate the potential ecological risk of zinc in soils. The study was conducted in southern Poland, in the Malopolska Province. This area is characterized by a great diversity of geological structures and types of land use and...

  2. Modulation of extrasynaptic NMDA receptors by synaptic and tonic zinc.

    Science.gov (United States)

    Anderson, Charles T; Radford, Robert J; Zastrow, Melissa L; Zhang, Daniel Y; Apfel, Ulf-Peter; Lippard, Stephen J; Tzounopoulos, Thanos

    2015-05-19

    Many excitatory synapses contain high levels of mobile zinc within glutamatergic vesicles. Although synaptic zinc and glutamate are coreleased, it is controversial whether zinc diffuses away from the release site or whether it remains bound to presynaptic membranes or proteins after its release. To study zinc transmission and quantify zinc levels, we required a high-affinity rapid zinc chelator as well as an extracellular ratiometric fluorescent zinc sensor. We demonstrate that tricine, considered a preferred chelator for studying the role of synaptic zinc, is unable to efficiently prevent zinc from binding low-nanomolar zinc-binding sites, such as the high-affinity zinc-binding site found in NMDA receptors (NMDARs). Here, we used ZX1, which has a 1 nM zinc dissociation constant and second-order rate constant for binding zinc that is 200-fold higher than those for tricine and CaEDTA. We find that synaptic zinc is phasically released during action potentials. In response to short trains of presynaptic stimulation, synaptic zinc diffuses beyond the synaptic cleft where it inhibits extrasynaptic NMDARs. During higher rates of presynaptic stimulation, released glutamate activates additional extrasynaptic NMDARs that are not reached by synaptically released zinc, but which are inhibited by ambient, tonic levels of nonsynaptic zinc. By performing a ratiometric evaluation of extracellular zinc levels in the dorsal cochlear nucleus, we determined the tonic zinc levels to be low nanomolar. These results demonstrate a physiological role for endogenous synaptic as well as tonic zinc in inhibiting extrasynaptic NMDARs and thereby fine tuning neuronal excitability and signaling.

  3. Modulation of extrasynaptic NMDA receptors by synaptic and tonic zinc

    Science.gov (United States)

    Anderson, Charles T.; Radford, Robert J.; Zastrow, Melissa L.; Zhang, Daniel Y.; Apfel, Ulf-Peter; Lippard, Stephen J.; Tzounopoulos, Thanos

    2015-01-01

    Many excitatory synapses contain high levels of mobile zinc within glutamatergic vesicles. Although synaptic zinc and glutamate are coreleased, it is controversial whether zinc diffuses away from the release site or whether it remains bound to presynaptic membranes or proteins after its release. To study zinc transmission and quantify zinc levels, we required a high-affinity rapid zinc chelator as well as an extracellular ratiometric fluorescent zinc sensor. We demonstrate that tricine, considered a preferred chelator for studying the role of synaptic zinc, is unable to efficiently prevent zinc from binding low-nanomolar zinc-binding sites, such as the high-affinity zinc-binding site found in NMDA receptors (NMDARs). Here, we used ZX1, which has a 1 nM zinc dissociation constant and second-order rate constant for binding zinc that is 200-fold higher than those for tricine and CaEDTA. We find that synaptic zinc is phasically released during action potentials. In response to short trains of presynaptic stimulation, synaptic zinc diffuses beyond the synaptic cleft where it inhibits extrasynaptic NMDARs. During higher rates of presynaptic stimulation, released glutamate activates additional extrasynaptic NMDARs that are not reached by synaptically released zinc, but which are inhibited by ambient, tonic levels of nonsynaptic zinc. By performing a ratiometric evaluation of extracellular zinc levels in the dorsal cochlear nucleus, we determined the tonic zinc levels to be low nanomolar. These results demonstrate a physiological role for endogenous synaptic as well as tonic zinc in inhibiting extrasynaptic NMDARs and thereby fine tuning neuronal excitability and signaling. PMID:25947151

  4. Effect of Zinc Oxide Nanoparticles and Sodium Hydroxide on the Self-Cleaning and Antibacterial Properties of Polyethylene Terephthalate

    Directory of Open Access Journals (Sweden)

    Mohammad Mirjalili

    2017-12-01

    Full Text Available In this study, the synthesis of zinc oxide nanoparticles was carried out, together with the hydrolysis of polyethylene terephthalate, using sodium hydroxide to increase surface activity and enhance nanoparticle adsorption. Polyester fabrics were treated with zinc acetate and sodium hydroxide in an ultrasonic bath, resulting in the formation of ZnO nanospheres. The presence of zinc oxide on the surface of the polyethylene terephthalate was confi rmed using scanning electron microscopy (SEM and energy-dispersive X-ray spectroscopy (EDS. The self-cleaning property of treated fabrics was evaluated through discolouring using methylene blue stain under solar irradiation. The antibacterial activities of the samples against common pathogenic bacteria, including Escherichia coli and Staphylococcus aureus, were also assessed. The results indicated that the photocatalytic and antibacterial activities of the ultrasound-treated polyethylene terephthalate improved significantly.

  5. Structure data of elements and intermetallic phases. SubVol. B. Sulfides, selenides, tellurides. Pt. 1. Ag-Al-Cd-S. Cu-Te-Yb

    Energy Technology Data Exchange (ETDEWEB)

    Hellwege, K H; Hellwege, A M [eds.; Eisenmann, B; Schaefer, H

    1986-01-01

    Volume III/14 'Structure data of elements and intermetallic phases' is a supplement to and extension of Volume III/6. Since the publication of III/6 in 1971 (considering original papers up to 1967), the amount of new information for these substances has increased rapidly. Therefore the data had to be divided into several parts. The first part, III/14b1, is presented herewith. In Volume III/6, simple sulfides, selenides and tellurides were treated together with the intermetallic phases. The data are compiled in the same way as in III/6: for each substance the space group, lattice constants, their dependence on temperature and pressure, and other information is listed in the tables. In several cases, mostly for solid solutions, diagrams are given which are added in a separate chapter. Original papers containing a complete structure analysis are referred to in the tables. (orig./GSCH).

  6. Thermochemical properties of silver tellurides including empressite (AgTe) and phase diagrams for Ag-Te and Ag-Te-O

    Science.gov (United States)

    Voronin, Mikhail V.; Osadchii, Evgeniy G.; Brichkina, Ekaterina A.

    2017-10-01

    This study compiles original experimental and literature data on the thermodynamic properties (ΔfG°, S°, ΔfH°) of silver tellurides (α-Ag2Te, β-Ag2Te, Ag1.9Te, Ag5Te3, AgTe) obtained by the method of solid-state galvanic cell with the RbAg4I5 and AgI solid electrolytes. The thermodynamic data for empressite (AgTe, pure fraction from Empress Josephine Mine, Colorado USA) have been obtained for the first time by the electrochemical experiment with the virtual reaction Ag + Te = AgTe. The Ag-Te phase diagrams in the T - x and log fTe2 (gas) - 1/ T coordinates have been refined, and the ternary Ag-Te-O diagrams with Ag-Te-TeO2 (paratellurite) composition range have been calculated.

  7. Molecular precursors for the phase-change material germanium-antimony-telluride, Ge{sub 2}Sb{sub 2}Te{sub 5} (GST)

    Energy Technology Data Exchange (ETDEWEB)

    Harmgarth, Nicole; Zoerner, Florian; Engelhardt, Felix; Edelmann, Frank T. [Chemisches Institut, Otto-von-Guericke-Universitaet Magdeburg (Germany); Liebing, Phil [Laboratorium fuer Anorganische Chemie, ETH Zuerich (Switzerland); Burte, Edmund P.; Silinskas, Mindaugas [Institut fuer Mikro- und Sensorsysteme, Otto-von-Guericke-Universitaet Magdeburg (Germany)

    2017-10-04

    This review provides an overview of the precursor chemistry that has been developed around the phase-change material germanium-antimony-telluride, Ge{sub 2}Sb{sub 2}Te{sub 5} (GST). Thin films of GST can be deposited by employing either chemical vapor deposition (CVD) or atomic layer deposition (ALD) techniques. In both cases, the success of the layer deposition crucially depends on the proper choice of suitable molecular precursors. Previously reported processes mainly relied on simple alkoxides, alkyls, amides and halides of germanium, antimony, and tellurium. More sophisticated precursor design provided a number of promising new aziridinides and guanidinates. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Formation and acceleration of uniformly filled ellipsoidal electron bunches obtained via space-charge-driven expansion from a cesium-telluride photocathode

    Directory of Open Access Journals (Sweden)

    P. Piot

    2013-01-01

    Full Text Available We report the experimental generation, acceleration, and characterization of a uniformly filled electron bunch obtained via space-charge-driven expansion (often referred to as “blow-out regime” in an L-band (1.3-GHz radiofrequency photoinjector. The beam is photoemitted from a cesium-telluride semiconductor photocathode using a short (<200  fs ultraviolet laser pulse. The produced electron bunches are characterized with conventional diagnostics and the signatures of their ellipsoidal character are observed. We especially demonstrate the production of ellipsoidal bunches with charges up to ∼0.5  nC corresponding to a ∼20-fold increase compared to previous experiments with metallic photocathodes.

  9. Thermal Recycling of Waelz Oxide Using Concentrated Solar Energy

    Science.gov (United States)

    Tzouganatos, N.; Matter, R.; Wieckert, C.; Antrekowitsch, J.; Gamroth, M.; Steinfeld, A.

    2013-12-01

    The dominating Zn recycling process is the so-called Waelz process. Waelz oxide (WOX), containing 55-65% Zn in oxidic form, is mainly derived from electric arc furnace dust produced during recycling of galvanized steel. After its wash treatment to separate off chlorides, WOX is used as feedstock along with ZnS concentrates for the electrolytic production of high-grade zinc. Novel and environmentally cleaner routes for the purification of WOX and the production of Zn are investigated using concentrated solar energy as the source of high-temperature process heat. The solar-driven clinkering of WOX and its carbothermal reduction were experimentally demonstrated using a 10 kWth packed-bed solar reactor. Solar clinkering at above 1265°C reduced the amount of impurities below 0.1 wt.%. Solar carbothermal reduction using biocharcoal as reducing agent in the 1170-1320°C range yielded 90 wt.% Zn.

  10. Dietary Zinc Intake and Plasma Zinc Concentrations in Children with Short Stature and Failure to Thrive.

    Science.gov (United States)

    Yazbeck, Nadine; Hanna-Wakim, Rima; El Rafei, Rym; Barhoumi, Abir; Farra, Chantal; Daher, Rose T; Majdalani, Marianne

    2016-01-01

    The burden of zinc deficiency on children includes an increased incidence of diarrhea, failure to thrive (FTT) and short stature. The aim of this study was to assess whether children with FTT and/or short stature have lower dietary zinc intake and plasma zinc concentrations compared to controls. A case-control study conducted at the American University of Beirut Medical Center included 161 subjects from 1 to 10 years of age. Cases had a statistically significant lower energy intake (960.9 vs. 1,135.2 kcal for controls, p = 0.010), lower level of fat (30.3 vs. 36.5 g/day, p = 0.0043) and iron intake (7.4 vs. 9.1 mg/day, p = 0.034). There was no difference in zinc, copper, carbohydrate and protein intake between the 2 groups. The plasma zinc concentration did not differ between the cases and controls (97.4 vs. 98.2 μg/dl, p = 0.882). More cases had mild-to-moderate zinc deficiency when compared to controls with 10.3 vs. 3.6%, p = 0.095. Our study did not show statistically significant difference in dietary zinc intake and plasma zinc concentrations between children with FTT and/or short stature compared to healthy controls. A prospective study is planned to assess the effect of zinc supplementation on growth parameters in FTT children. © 2016 S. Karger AG, Basel.

  11. Associations between Dietary Iron and Zinc Intakes, and between Biochemical Iron and Zinc Status in Women

    Directory of Open Access Journals (Sweden)

    Karen Lim

    2015-04-01

    Full Text Available Iron and zinc are found in similar foods and absorption of both may be affected by food compounds, thus biochemical iron and zinc status may be related. This cross-sectional study aimed to: (1 describe dietary intakes and biochemical status of iron and zinc; (2 investigate associations between dietary iron and zinc intakes; and (3 investigate associations between biochemical iron and zinc status in a sample of premenopausal women aged 18–50 years who were recruited in Melbourne and Sydney, Australia. Usual dietary intakes were assessed using a 154-item food frequency questionnaire (n = 379. Iron status was assessed using serum ferritin and hemoglobin, zinc status using serum zinc (standardized to 08:00 collection, and presence of infection/inflammation using C-reactive protein (n = 326. Associations were explored using multiple regression and logistic regression. Mean (SD iron and zinc intakes were 10.5 (3.5 mg/day and 9.3 (3.8 mg/day, respectively. Median (interquartile range serum ferritin was 22 (12–38 μg/L and mean serum zinc concentrations (SD were 12.6 (1.7 μmol/L in fasting samples and 11.8 (2.0 μmol/L in nonfasting samples. For each 1 mg/day increase in dietary iron intake, zinc intake increased by 0.4 mg/day. Each 1 μmol/L increase in serum zinc corresponded to a 6% increase in serum ferritin, however women with low serum zinc concentration (AM fasting < 10.7 μmol/L; AM nonfasting < 10.1 μmol/L were not at increased risk of depleted iron stores (serum ferritin <15 μg/L; p = 0.340. Positive associations were observed between dietary iron and zinc intakes, and between iron and zinc status, however interpreting serum ferritin concentrations was not a useful proxy for estimating the likelihood of low serum zinc concentrations and women with depleted iron stores were not at increased risk of impaired zinc status in this cohort.

  12. Leptin, NPY, Melatonin and Zinc Levels in Experimental Hypothyroidism and Hyperthyroidism: The Relation to Zinc.

    Science.gov (United States)

    Baltaci, Abdulkerim Kasım; Mogulkoc, Rasim

    2017-06-01

    Since zinc mediates the effects of many hormones or is found in the structure of numerous hormone receptors, zinc deficiency leads to various functional impairments in the hormone balance. And also thyroid hormones have important activity on metabolism and feeding. NPY and leptin are affective on food intake and regulation of appetite. The present study is conducted to determine how zinc supplementation and deficiency affect thyroid hormones (free and total T3 and T4), melatonin, leptin, and NPY levels in thyroid dysfunction in rats. The experiment groups in the study were formed as follows: Control (C); Hypothyroidism (PTU); Hypothyroidism+Zinc (PTU+Zn); Hypothyroidism+Zinc deficient; Hyperthyroidism (H); Hyperthyroidism+Zinc (H+Zn); and Hyperthyroidism+Zinc deficient. Thyroid hormone parameters (FT 3 , FT 4 , TT 3 , and TT 4 ) were found to be reduced in hypothyroidism groups and elevated in the hyperthyroidism groups. Melatonin values increased in hyperthyroidism and decreased in hypothyroidism. Leptin and NPY levels both increased in hypo- and hyperthyroidism. Zinc levels, on the other hand, decreased in hypothyroidism and increased in hyperthyroidism. Zinc supplementation, particularly when thyroid function is impaired, has been demonstrated to markedly prevent these changes.

  13. Availability of native and fertilizer zinc in some Indian soils: studies with 65Zinc

    International Nuclear Information System (INIS)

    Chaudhury, J.; Deb, D.L.

    1979-01-01

    Isotopically exchangeable zinc (Et values) was determined by different methods in some soils having pH(H 2 O) varying from 3.05 to 8.40 using 65 Zn. The Et values obtained using different extractants showed significant correlation with available zinc, organic carbon and soil pH. The recovery of applied zinc in the aqueous phase was less than one percent in most of the soils having pH higher than 7.0. Application of zinc with complexing agents like DTPA and EDTA increased the recovery of applied zinc in the solution to about 95 percent. Soil pH, organic C and DTPA extractable zinc showed significant relationship with the recovery of applied zinc under different treatments. Use of EDTA and DTPA extractants reduced the zinc buffering capacity of soil to a value less than one, irrespective of the initial pH of the soil, whereas the values were comparatively higher in presence of different levels of zinc carrier. (auth.)

  14. Solar India - 82: national solar energy convention

    Energy Technology Data Exchange (ETDEWEB)

    1982-01-01

    This document is the proceedings of the Solar India - 82 conference, which was held 17-19 December 1982. The papers are organized into functional groupings which include: (1) solar radiation, (2) flat plate solar collectors and solar water heaters, (3) solar concentrators, (4) solar air heaters and dryers, (5) solar ponds and energy storage, (6) solar cookers, (7) solar stills, (8) selective coatings, (9) photovoltaics, (10) space heating and cooling, (11) bio-energy, and (12) miscellaneous papers. The vast majority of the papers describe work carried out in India, the vast majority of the papers also contain relatively readable abstracts.

  15. Solar Features - Solar Flares - Patrol

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The H-alpha Flare Patrol identifies time periods each day when the sun is being continuously monitored by select ground-based solar observatories.

  16. Solar Features - Solar Flares - SIDS

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Sudden Ionospheric Disturbance (SID) is any of several radio propagation anomalies due to ionospheric changes resulting from solar or geophysical events.

  17. The protective nature of passivation films on zinc: surface charge

    International Nuclear Information System (INIS)

    Muster, Tim H.; Cole, Ivan S.

    2004-01-01

    The influence of oxide surface charge on the corrosion performance of zinc metals was investigated. Oxidised zinc species (zinc oxide, zinc hydroxychloride, zinc hydroxysulfate and zinc hydroxycarbonate) with chemical compositions similar to those produced on zinc during atmospheric corrosion were formed as particles from aqueous solution, and as passive films deposited onto zinc powder, and rolled zinc, surfaces. Synthesized oxides were characterised by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and electron probe X-ray microanalysis. The zeta potentials of various oxide particles, as determined by microelectrophoresis, are reported as a function of pH. Particulates containing a majority of zinc hydroxycarbonate and zinc hydroxysulfate crystallites were found to possess a negative surface charge below pH 6, whilst zinc oxide-hydroxide and zinc hydroxychloride crystallites possessed isoelectric points (IEP's) higher than pH 8. The ability of chloride species to pass through a bed of 3 μm diameter zinc powder was found to increase for surfaces possessing carboxy and sulfate surface species, suggesting that negatively charged surfaces can aid in the repulsion of chloride ions. Electrochemical analysis of the open-circuit potential as a function of time at a fixed pH of 6.5 showed that the chemical composition of passive films on zinc plates influenced the ability of chloride ions to access anodic sites for periods of approximately 1 h

  18. Solar Energy Innovation Network | Solar Research | NREL

    Science.gov (United States)

    Energy Innovation Network Solar Energy Innovation Network The Solar Energy Innovation Network grid. Text version The Solar Energy Innovation Network is a collaborative research effort administered (DOE) Solar Energy Technologies Office to develop and demonstrate new ways for solar energy to improve

  19. Zinc-induced protection against cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Early, J.L.; Schnell, R.C.

    1978-02-01

    Pretreatment of male rats with cadmium acetate potentiates the duration of hexobarbital hypnosis and inhibits the rate of hepatic microsomal drug metabolism. Pretreatment of rats with zinc acetate protects against these alterations in drug action elicited by cadmium.

  20. Anaerobic Digestion Alters Copper and Zinc Speciation.

    Science.gov (United States)

    Legros, Samuel; Levard, Clément; Marcato-Romain, Claire-Emmanuelle; Guiresse, Maritxu; Doelsch, Emmanuel

    2017-09-19

    Anaerobic digestion is a widely used organic waste treatment process. However, little is known on how it could alter the speciation of contaminants in organic waste. This study was focused on determining the influence of anaerobic digestion on the speciation of copper and zinc, two metals that generally occur at high concentration in organic waste. Copper and zinc speciation was investigated by X-ray absorption spectroscopy in four different raw organic wastes (predigestion) and their digested counterparts (postdigestion, i.e., digestates). The results highlighted an increase in the digestates of the proportion of amorphous or nanostructured copper sulfides as well as amorphous or nanostructured zinc sulfides and zinc phosphate as compared to raw waste. We therefore suggest that the environmental fate of these elements would be different when spreading either digestates or raw waste on cropland.