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Sample records for cadmium arsenide solar cells

  1. Heat blocking gallium arsenide solar cells

    Science.gov (United States)

    Rahman, F.; Farmer, C. D.; Schmidt, C.; Pfaff, G.; Stanley, C. R.

    2008-02-01

    The solar cell industry is witnessing an era of unprecedented growth and this trend is set to continue for the foreseeable future. Here we describe a heat reflection pigment-coated single-junction gallium arsenide solar cell that is capable of reflecting heat-inducing near-infrared radiation. The cell maintains its performance better than non-coated cells when exposed to infrared-rich radiant flux. In situations where solar cells get heated mainly from incident infrared radiation, these cells exhibit superior performance. The heat reflecting pigment, cell structure, coating process and cell performance have been described.

  2. Window structure for passivating solar cells based on gallium arsenide

    Science.gov (United States)

    Barnett, Allen M. (Inventor)

    1985-01-01

    Passivated gallium arsenide solar photovoltaic cells with high resistance to moisture and oxygen are provided by means of a gallium arsenide phosphide window graded through its thickness from arsenic rich to phosphorus rich.

  3. Superlattice Intermediate Band Solar Cell on Gallium Arsenide

    Science.gov (United States)

    2015-02-09

    AFRL-RV-PS- AFRL-RV-PS- TR-2015-0048 TR-2015-0048 SUPERLATTICE INTERMEDIATE BAND SOLAR CELL ON GALLIUM ARSENIDE Alexandre Freundlich...SUBTITLE 5a. CONTRACT NUMBER FA9453-13-1-0232 Superlattice Intermediate Band Solar Cell on Gallium Arsenide 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER

  4. Gallium Arsenide solar cell radiation damage experiment

    Science.gov (United States)

    Maurer, R. H.; Kinnison, J. D.; Herbert, G. A.; Meulenberg, A.

    1991-01-01

    Gallium arsenide (GaAs) solar cells for space applications from three different manufactures were irradiated with 10 MeV protons or 1 MeV electrons. The electrical performance of the cells was measured at several fluence levels and compared. Silicon cells were included for reference and comparison. All the GaAs cell types performed similarly throughout the testing and showed a 36 to 56 percent power areal density advantage over the silicon cells. Thinner (8-mil versus 12-mil) GaAs cells provide a significant weight reduction. The use of germanium (Ge) substrates to improve mechanical integrity can be implemented with little impact on end of life performance in a radiation environment.

  5. Development of a Multi-layer Anti-reflective Coating for Gallium Arsenide/Aluminum Gallium Arsenide Solar Cells

    Science.gov (United States)

    2015-07-01

    Aluminum Gallium Arsenide Solar Cells by Kimberley A Olver Approved for public release; distribution unlimited...Development of a Multi-layer Anti-reflective Coating for Gallium Arsenide/Aluminum Gallium Arsenide Solar Cells by Kimberley A Olver...Aluminum Gallium Arsenide (AlGaAs) Solar Cells 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Kimberley A Olver

  6. Testing of gallium arsenide solar cells on the CRRES vehicle

    Science.gov (United States)

    Trumble, T. M.

    A flight experiment was designed to determine the optimum design for gallium arsenide (GaAs) solar cell panels in a radiation environment. Elements of the experiment design include, different coverglass material and thicknesses, welded and soldered interconnects, different solar cell efficiencies, different solar cell types, and measurement of annealing properties. This experiment is scheduled to fly on the Combined Release and Radiation Effects Satellite (CRRES). This satellite will simultaneously measure the radiation environment and provide engineering data on solar cell degradation that can be directly related to radiation damage.

  7. Cadmium sulfide solar cells

    Science.gov (United States)

    Stanley, A. G.

    1975-01-01

    Development, fabrication and applications of CdS solar cells are reviewed in detail. The suitability of CdS cells for large solar panels and microcircuitry, and their low cost, are emphasized. Developments are reviewed by manufacturer-developer. Vapor phase deposition of thin-film solar cells, doping and co-evaporation, sputtering, chemical spray, and sintered layers are reviewed, in addition to spray deposition, monograin layer structures, and silk screening. Formation of junctions by electroplating, evaporation, brushing, CuCl dip, and chemiplating are discussed, along with counterelectrode fabrication, VPD film structures, the Cu2S barrier layer, and various photovoltaic effects (contact photovoltage, light intensity variation, optical enhancement), and various other CdS topics.

  8. Indium Phosphide Window Layers for Indium Gallium Arsenide Solar Cells

    Science.gov (United States)

    Jain, Raj K.

    2005-01-01

    Window layers help in reducing the surface recombination at the emitter surface of the solar cells resulting in significant improvement in energy conversion efficiency. Indium gallium arsenide (In(x)Ga(1-x)As) and related materials based solar cells are quite promising for photovoltaic and thermophotovoltaic applications. The flexibility of the change in the bandgap energy and the growth of InGaAs on different substrates make this material very attractive for multi-bandgap energy, multi-junction solar cell approaches. The high efficiency and better radiation performance of the solar cell structures based on InGaAs make them suitable for space power applications. This work investigates the suitability of indium phosphide (InP) window layers for lattice-matched In(0.53)Ga(0.47)As (bandgap energy 0.74 eV) solar cells. We present the first data on the effects of the p-type InP window layer on p-on-n lattice-matched InGaAs solar cells. The modeled quantum efficiency results show a significant improvement in the blue region with the InP window. The bare InGaAs solar cell performance suffers due to high surface recombination velocity (10(exp 7) cm/s). The large band discontinuity at the InP/InGaAs heterojunction offers a great potential barrier to minority carriers. The calculated results demonstrate that the InP window layer effectively passivates the solar cell front surface, hence resulting in reduced surface recombination and therefore, significantly improving the performance of the InGaAs solar cell.

  9. The comparison between gallium arsenide and indium gallium arsenide as materials for solar cell performance using Silvaco application

    Energy Technology Data Exchange (ETDEWEB)

    Zahari, Suhaila Mohd; Norizan, Mohd Natashah; Mohamad, Ili Salwani; Osman, Rozana Aina Maulat; Taking, Sanna [School of Microelectronic Engineering, Universiti Malaysia Perlis, Kampus Pauh Putra, 02600 Arau, Perlis (Malaysia)

    2015-05-15

    The work presented in this paper is about the development of single and multilayer solar cells using GaAs and InGaAs in AM1.5 condition. The study includes the modeling structure and simulation of the device using Silvaco applications. The performance in term of efficiency of Indium Gallium Arsenide (InGaAs) and GaAs material was studied by modification of the doping concentration and thickness of material in solar cells. The efficiency of the GaAs solar cell was higher than InGaAs solar cell for single layer solar cell. Single layer GaAs achieved an efficiency about 25% compared to InGaAs which is only 2.65% of efficiency. For multilayer which includes both GaAs and InGaAs, the output power, P{sub max} was 8.91nW/cm² with the efficiency only 8.51%. GaAs is one of the best materials to be used in solar cell as a based compared to InGaAs.

  10. The comparison between gallium arsenide and indium gallium arsenide as materials for solar cell performance using Silvaco application

    Science.gov (United States)

    Zahari, Suhaila Mohd; Norizan, Mohd Natashah; Mohamad, Ili Salwani; Osman, Rozana Aina Maulat; Taking, Sanna

    2015-05-01

    The work presented in this paper is about the development of single and multilayer solar cells using GaAs and InGaAs in AM1.5 condition. The study includes the modeling structure and simulation of the device using Silvaco applications. The performance in term of efficiency of Indium Gallium Arsenide (InGaAs) and GaAs material was studied by modification of the doping concentration and thickness of material in solar cells. The efficiency of the GaAs solar cell was higher than InGaAs solar cell for single layer solar cell. Single layer GaAs achieved an efficiency about 25% compared to InGaAs which is only 2.65% of efficiency. For multilayer which includes both GaAs and InGaAs, the output power, Pmax was 8.91nW/cm² with the efficiency only 8.51%. GaAs is one of the best materials to be used in solar cell as a based compared to InGaAs.

  11. Two years of on-orbit gallium arsenide performance from the LIPS solar cell panel experiment

    Science.gov (United States)

    Francis, R. W.; Betz, F. E.

    1985-01-01

    The LIPS on-orbit performance of the gallium arsenide panel experiment was analyzed from flight operation telemetry data. Algorithms were developed to calculate the daily maximum power and associated solar array parameters by two independent methods. The first technique utilizes a least mean square polynomial fit to the power curve obtained with intensity and temperature corrected currents and voltages; whereas, the second incorporates an empirical expression for fill factor based on an open circuit voltage and the calculated series resistance. Maximum power, fill factor, open circuit voltage, short circuit current and series resistance of the solar cell array are examined as a function of flight time. Trends are analyzed with respect to possible mechanisms which may affect successive periods of output power during 2 years of flight operation. Degradation factors responsible for the on-orbit performance characteristics of gallium arsenide are discussed in relation to the calculated solar cell parameters. Performance trends and the potential degradation mechanisms are correlated with existing laboratory and flight data on both gallium arsenide and silicon solar cells for similar environments.

  12. One-Dimensional Fast Transient Simulator for Modeling Cadmium Sulfide/Cadmium Telluride Solar Cells

    Science.gov (United States)

    Guo, Da

    Solar energy, including solar heating, solar architecture, solar thermal electricity and solar photovoltaics, is one of the primary alternative energy sources to fossil fuel. Being one of the most important techniques, significant research has been conducted in solar cell efficiency improvement. Simulation of various structures and materials of solar cells provides a deeper understanding of device operation and ways to improve their efficiency. Over the last two decades, polycrystalline thin-film Cadmium-Sulfide and Cadmium-Telluride (CdS/CdTe) solar cells fabricated on glass substrates have been considered as one of the most promising candidate in the photovoltaic technologies, for their similar efficiency and low costs when compared to traditional silicon-based solar cells. In this work a fast one dimensional time-dependent/steady-state drift-diffusion simulator, accelerated by adaptive non-uniform mesh and automatic time-step control, for modeling solar cells has been developed and has been used to simulate a CdS/CdTe solar cell. These models are used to reproduce transients of carrier transport in response to step-function signals of different bias and varied light intensity. The time-step control models are also used to help convergence in steady-state simulations where constrained material constants, such as carrier lifetimes in the order of nanosecond and carrier mobility in the order of 100 cm2/Vs, must be applied.

  13. Improved defect analysis of Gallium Arsenide solar cells using image enhancement

    Science.gov (United States)

    Kilmer, Louis C.; Honsberg, Christiana; Barnett, Allen M.; Phillips, James E.

    1989-01-01

    A new technique has been developed to capture, digitize, and enhance the image of light emission from a forward biased direct bandgap solar cell. Since the forward biased light emission from a direct bandgap solar cell has been shown to display both qualitative and quantitative information about the solar cell's performance and its defects, signal processing techniques can be applied to the light emission images to identify and analyze shunt diodes. Shunt diodes are of particular importance because they have been found to be the type of defect which is likely to cause failure in a GaAs solar cell. The presence of a shunt diode can be detected from the light emission by using a photodetector to measure the quantity of light emitted at various current densities. However, to analyze how the shunt diodes affect the quality of the solar cell the pattern of the light emission must be studied. With the use of image enhancement routines, the light emission can be studied at low light emission levels where shunt diode effects are dominant.

  14. Gallium arsenide single crystal solar cell structure and method of making

    Science.gov (United States)

    Stirn, Richard J. (Inventor)

    1983-01-01

    A production method and structure for a thin-film GaAs crystal for a solar cell on a single-crystal silicon substrate (10) comprising the steps of growing a single-crystal interlayer (12) of material having a closer match in lattice and thermal expansion with single-crystal GaAs than the single-crystal silicon of the substrate, and epitaxially growing a single-crystal film (14) on the interlayer. The material of the interlayer may be germanium or graded germanium-silicon alloy, with low germanium content at the silicon substrate interface, and high germanium content at the upper surface. The surface of the interface layer (12) is annealed for recrystallization by a pulsed beam of energy (laser or electron) prior to growing the interlayer. The solar cell structure may be grown as a single-crystal n.sup.+ /p shallow homojunction film or as a p/n or n/p junction film. A Ga(Al)AS heteroface film may be grown over the GaAs film.

  15. Radiation and temperature effects in gallium arsenide, indium phosphide, and silicon solar cells

    Science.gov (United States)

    Weinberg, I.; Swartz, C. K.; Hart, R. E., Jr.; Statler, R. L.

    1987-01-01

    The effects of radiation on performance are determined for both n+p and p+n GaAs and InP cells and for silicon n+p cells. It is found that the radiation resistance of InP is greater than that of both GaAs and Si under 1-MeV electron irradiation. For silicon, the observed decreased radiation resistance with decreased resistivity is attributed to the presence of a radiation-induced boron-oxygen defect. Comparison of radiation damage in both p+n and n+p GaAs cells yields a decreased radiation resistance for the n+p cell attributable to increased series resistance, decreased shunt resistance, and relatively greater losses in the cell's p-region. For InP, the n+p configuration is found to have greater radiation resistance than the p+n cell. The increased loss in this latter cell is attributed to losses in the cell's emitter region. Temperature dependency results are interpreted using a theoretical relation for dVoc/dT, which predicts that increased Voc should result in decreased numerical values for dPm/dT. The predicted correlation is observed for GaAs but not for InP, a result which is attributed to variations in cell processing.

  16. A Novel Approach to Modeling the Effects of Radiation in Gallium-Arsenide Solar Cells Using Silvaco's ATLAS Software

    National Research Council Canada - National Science Library

    Crespin, Aaron

    2004-01-01

    The effects of radiation in GaAs solar cells has been extensively researched and the results of numerous investigation have yielded a considerable amount of information about the degradation in irradiated solar cells...

  17. Use of solar cell in electrokinetic remediation of cadmium-contaminated soil.

    Science.gov (United States)

    Yuan, Songhu; Zheng, Zhonghua; Chen, Jing; Lu, Xiaohua

    2009-03-15

    This preliminary study used a solar cell, instead of direct current (DC) power supply, to generate electric field for electrokinetic (EK) remediation of cadmium-contaminated soil. Three EK tests were conducted and compared; one was conducted on a cloudy and rainy day with solar cell, one was conducted on a sunny day with solar cell and another was conducted periodically with DC power supply. It was found that the output potential of solar cell depended on daytime and was influenced by weather conditions; the applied potential in soil was affected by the output potential and weather conditions, and the current achieved by solar cell was comparable with that achieved by DC power supply. Solar cell could be used to drive the electromigration of cadmium in contaminated soil, and removal efficiency achieved by solar cell was comparable with that achieved by DC power supply. Compared with traditional DC power supply, using solar cell as power supply for EK remediation can greatly reduce energy expenditure. This study provided an alternative to improve the EK soil remediation and expanded the use of solar cell in environmental remediation.

  18. Photoluminescence Excitation Spectroscopy Characterization of Cadmium Telluride Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Moore, James E.; Wang, Xufeng; Grubbs, Elizabeth K.; Drayton, Jennifer; Johnston, Steve; Levi, Dean; Lundstrom, Mark S.; Bermel, Peter

    2016-11-21

    The use of steady-state photoluminescence spectroscopy as a contactless characterization tool, suitable for inline optical characterization, has been previously demonstrated for high efficiency solar cells such as GaAs. In this paper, we demonstrate the use of PLE characterization on a thin film CdS/CdTe np heterojunction solar cell, and compare the results to measured EQE and I-V data. In contrast to previous work on high-quality GaAs, the PLE and EQE spectra do not match closely here. We still find, however, that reliable material parameters can be extracted from the PLE measurements. We also provide a physical explanation of the limits defining the cases when the PLE and EQE spectra may be expected to match.

  19. Back contact formation in thin cadmium telluride solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Haedrich, M., E-mail: mathias.haedrich@uni-jena.de; Heisler, C.; Reisloehner, U.; Kraft, C.; Metzner, H.

    2011-08-31

    We present a model describing the undesired roll-over which is a well-known phenomenon in the current-voltage characteristics of CdTe solar cells. Therein, the roll-over is ascribed to a Schottky barrier at the back contact which is effective as a reverse diode. The formation of this barrier is investigated depending on the CdTe absorber thickness as well as on the employed back contact metal. Computer simulations of the energy band diagram reveal that the back contact barrier can be reduced and even eliminated for sufficiently thin absorbers. The reason is the spatial overlap between the space-charge regions of the p-n heterojunction with the one of the back contact. This behaviour correlates with experimental current-voltage data of solar cells with a simple gold back contact. In the latter, the roll-over is considerable for absorbers with 3 to 5 {mu}m thickness, diminishes when the absorber thickness is reduced and finally vanishes when the absorber thickness is approximately 1 {mu}m. The investigations show that thickness reduction can be employed in order to suppress the roll-over phenomenon in CdTe solar cells.

  20. A COMPARATIVE ANALYSIS OF SILICON AND CADMIUM TELLURIDE BASED SOLAR CELLS

    Directory of Open Access Journals (Sweden)

    Amjad Al QASSEM

    2016-12-01

    Full Text Available A compartive analzsis of silicon solar cells and of those containing a CdTe thin film which are widely used in solar energetics, particullarilly, in photovoltaic modules fabrication, is brought in this paper. The silicon is largely used in solar cells fabrication due to the low cost of solar cells production related to the low cost of the semiconductor fabrication and to the advanced material processing technology, when at the same time cadmium telluride has the wide use due to the fact that its fundamental parameters can provide theoretically a high value of efficiency of solar energy conversion into electrical one of 30%. The structure and photoelectrical parameters of silicon solar cells and of those cotaining a thin cadmium telluride layer are considered.ANALIZA COMPARATIVĂ A CELULELOR SOLARE DIN SILICIU ŞI TELURURA DE CADMIUÎn lucrarea de faţă este prezentată analiza comparativă a celulelor solare fabricate din siliciu şi a celor cu strat subţire de CdTe, care sunt pe larg utilizate în energetica solară, în particular la producerea modulelor fotovoltaice. Siliciul este intens folosit în fabricarea celulelor solare datorită costului redus al materialului semiconductor şi tehnologiei avansate de procesare, pe când telurura de cadmiu are o utilizare tot mai largă care, datorită parametrilor fundamentali, poate asigura teoretic o valoare înaltă a eficienţei conversiei energiei solare în cea electrică de (30%. Sunt considerate structura şi parametrii fotoelectrici ai celulelor solare din siliciu şi ai celor cu strat subţire de telurură de cadmiu.

  1. Influence of a front buffer layer on the performance of flexible Cadmium sulfide/Cadmium telluride solar cells

    Science.gov (United States)

    Mahabaduge, Hasitha Padmika

    Cadmium telluride (CdTe) solar cells have been developing as a promising candidate for large-scale application of photovoltaic energy conversion and have become the most commercially successful polycrystalline thin-film solar module material. In scaling up from small cells to large-area modules, inevitably non-uniformities across the large area will limit the performance of the large cell or module. The effects of these non-uniformities can be reduced by introducing a thin, high-resistivity transparent buffer layer between the conductive electrodes and the semiconductor diode. ZnO is explored in this dissertation as a high-resistivity transparent buffer layer for sputtered CdTe solar cells and efficiencies over 15% have been achieved on commercially available Pilkington TEC15M glass substrates. The highest open-circuit voltage of 0.858V achieved using the optimized ZnO buffer layer is among the best reported in the literature. The properties of ZnO:Al as a buffer are also investigated. We have shown that ZnO:Al can serve both as a transparent conducting oxide layer as well as a high-resistivity transparent layer for CdTe solar cells. ZnO:Al reactively sputtered with oxygen can give the necessary resistivities that allow it to be used as a high-resistivity transparent layer. Glass is the most common choice as the substrate for solar cells fabricated in the superstrate configuration due to its transparency and mechanical rigidity. However flexible substrates offer the advantages of light weight, high flexibility, ease of integrability and higher throughput through roll-to-roll processing over glass. This dissertation presents significant improvements made to flexible CdTe solar cells reporting an efficiency of 14% on clear KaptonRTM flexible polyimide substrates. Our efficiency of 14% is, to our knowledge, the best for any flexible CdTe cell reported in literature.

  2. Optimization and Characterization of Indium Arsenide Quantum Dots for Application in III-V Material Solar Cells

    Science.gov (United States)

    Podell, Adam P.

    In this work, InAs quantum dots grown by organometallic vapor-phase epitaxy (OMVPE) are investigated for application in III - V material solar cells. The first focus is on the opti- mization of growth parameters to produce high densities of uniform defect-free quantum dots via growth on 2" vicinal GaAs substrates. Parameters studied are InAs coverage, V/III ratio and growth rate. QDs are grown by the Stranski-Krastanov (SK) growth mode on (100) GaAs substrates misoriented toward (110) or (111) planes with various degrees of misorientation from 0° to 6°. Atomic force microscopy results indicated that as misorientation angle increased toward(110),critical thickness for quantum dot formation increased with theta c =1.8ML,1.9ML and 2.0 ML corresponding to 0°, 2° and 6°, respectively. Results for quantum dots grown on (111) misoriented substrates indicated, on average, that higher densities of quantum dots were achieved, compared with similar growths on substrates misoriented toward (110). Most notably, a stable average number density of 8 x 1010cm -2 was observed over a range of growth rates of 0.1ML/s - 0.4ML/s on (111) misoriented substrates compared with a decreasing number density as low as 2.85 x 1010cm -2 corresponding to a growth rate of 0.4ML/s grown on (110) misoriented substrates. p-i-n solar cell devices with a 10-layer quantum dot super- lattice imbedded in the i-region were also grown on (100) GaAs substrates misoriented 0°, 2° and 6° toward (110) as well as a set of devices grown on substrates misoriented toward (111). Device results showed a 1.0mA/cm2 enhancement to the short-circuit current for a v 2° misoriented device with 2.2 ML InAs coverage per quantum dot layer. Spectral response measurements were performed and integrated spectral response showed sub-GaAs bandgap short-circuit contribution which increased with increasing InAs coverage in the quantum dot layers from 0.04mA/cm2/ML, 0.28mA/cm2/ ML and 0.19mA/cm2/ML corresponding to 0°, 2

  3. Enhanced performance of hybrid solar cells using longer arms of quantum cadmium selenide tetrapods

    KAUST Repository

    Lee, Kyu-Sung

    2011-12-01

    We demonstrate that enhanced device performance of hybrid solar cells based on tetrapod (TP)-shaped cadmium selenide (CdSe) nanoparticles and conjugated polymer of poly (3-hexylthiophene) (P3HT) can be obtained by using longer armed tetrapods which aids in better spatial connectivity, thus decreasing charge hopping events which lead to better charge transport. Longer tetrapods with 10 nm arm length lead to improved power conversion efficiency of 1.12% compared to 0.80% of device having 5 nm short-armed tetrapods:P3HT photoactive blends.

  4. Cadmium Sulfide Nanoparticles Synthesized by Microwave Heating for Hybrid Solar Cell Applications

    Directory of Open Access Journals (Sweden)

    Claudia Martínez-Alonso

    2014-01-01

    Full Text Available Cadmium sulfide nanoparticles (CdS-n are excellent electron acceptor for hybrid solar cell applications. However, the particle size and properties of the CdS-n products depend largely on the synthesis methodologies. In this work, CdS-n were synthetized by microwave heating using thioacetamide (TA or thiourea (TU as sulfur sources. The obtained CdS-n(TA showed a random distribution of hexagonal particles and contained TA residues. The latter could originate the charge carrier recombination process and cause a low photovoltage (Voc, 0.3 V in the hybrid solar cells formed by the inorganic particles and poly(3-hexylthiophene (P3HT. Under similar synthesis conditions, in contrast, CdS-n synthesized with TU consisted of spherical particles with similar size and contained carbonyl groups at their surface. CdS-n(TU could be well dispersed in the nonpolar P3HT solution, leading to a Voc of about 0.6–0.8 V in the resulting CdS-n(TU : P3HT solar cells. The results of this work suggest that the reactant sources in microwave methods can affect the physicochemical properties of the obtained inorganic semiconductor nanoparticles, which finally influenced the photovoltaic performance of related hybrid solar cells.

  5. Space-based solar power conversion and delivery systems study. Volume 4: Energy conversion systems studies

    Science.gov (United States)

    1977-01-01

    Solar cells and optical configurations for the SSPS were examined. In this task, three specific solar cell materials were examined: single crystal silicon, single crystal gallium arsenide, and polycrystalline cadmium sulfide. The comparison of the three different cells on the basis of a subsystem parametric cost per kW of SSPS-generated power at the terrestrial utility interface showed that gallium arsenide was the most promising solar cell material at high concentration ratios. The most promising solar cell material with no concentration, was dependent upon the particular combination of parameters representing cost, mass and performance that were chosen to represent each cell in this deterministic comparative analysis. The potential for mass production, based on the projections of the present state-of-the-art would tend to favor cadmium sulfide in lieu of single crystal silicon or gallium arsenide solar cells.

  6. Efficient solution-processed small molecule: Cadmium selenide quantum dot bulk heterojunction solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Vinay, E-mail: drvinaygupta@netscape.net [Physics of Energy Harvesting Division, Organic and Hybrid Solar Cell Group, CSIR-National Physical Laboratory, New Delhi-110012 (India); Department of Physics, University of California, Santa Barbara, California 93106 (United States); Upreti, Tanvi; Chand, Suresh [Physics of Energy Harvesting Division, Organic and Hybrid Solar Cell Group, CSIR-National Physical Laboratory, New Delhi-110012 (India)

    2013-12-16

    We report bulk heterojunction solar cells based on blends of solution-processed small molecule [7,7′-(4,4-bis(2-ethylhexyl)-4H-silolo[3,2-b:4,5-b′]dithiophene-2,6-diyl) bis(6-fluoro-4-(5′-hexyl-[2,2′-bithiophen]-5yl)benzo[c] [1,2,5] thiadiazole)] p-DTS(FBTTh{sub 2}){sub 2}: Cadmium Selenide (CdSe) (70:30, 60:40, 50:50, and 40:60) in the device configuration: Indium Tin Oxide /poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/p-DTS(FBTTh{sub 2}){sub 2}: CdSe/Ca/Al. The optimized ratio of p-DTS(FBTTh{sub 2}){sub 2}:CdSe::60:40 leads to a short circuit current density (J{sub sc}) = 5.45 mA/cm{sup 2}, open circuit voltage (V{sub oc}) = 0.727 V, and fill factor (FF) = 51%, and a power conversion efficiency = 2.02% at 100 mW/cm{sup 2} under AM1.5G illumination. The J{sub sc} and FF are sensitive to the ratio of p-DTS(FBTTh{sub 2}){sub 2}:CdSe, which is a crucial factor for the device performance.

  7. Theoretical simulation of performances in CIGS thin-film solar cells with cadmium-free buffer layer

    Science.gov (United States)

    Luo, Kang; Sun, Yulin; Zhou, Liyu; Wang, Fang; Wu, Fang

    2017-08-01

    Copper indium gallium selenium (CIGS) thin film solar cells have become one of the hottest topics in solar energy due to their high photoelectric transformation efficiency. To real applications, CIGS thin film is covered by the buffer layer and absorption layer. Traditionally, cadmium sulfide (CdS) is inserted into the middle of the window layer (ZnO) and absorption layer (CIGS) as a buffer layer. However, the application of the GIGS/CdS thin film solar cells has been limited because of the environmental pollution resulting from the toxic cadmium atom. Although zinc sulfide (ZnS) has been proposed to be one of the candidates, the performance of such battery cells has not been investigated. Here, in this paper, we systematically study the possibility of using zinc sulfide (ZnS) as a buffer layer. By including the effects of thickness, concentration of a buffer layer, intrinsic layer and the absorbing layer, we find that photoelectric transformation efficiency of ZnO/ZnS(n)/CIGS(i)/CIGS(p) solar cell is about 17.22%, which is qualified as a commercial solar cell. Moreover, we also find that the open-circuit voltage is ∼0.60 V, the short-circuit current is ∼36.99 mA/cm2 and the filled factor is ∼77.44%. Therefore, our results suggest that zinc sulfide may be the potential candidate of CdS as a buffer layer. Project supported by the NSF of Jiangsu Province (No. BK20131420), the Postgraduate Innovation Project of Jiangsu Province (No. KYLX15_0926), and the NJFU Outstanding Young Scholars Funding.

  8. Superstrate and substrate type cadmium telluride solar cells and monolithic integration of photovoltaic modules

    Science.gov (United States)

    Matulionis, Ilvydas

    This dissertation describes the fabrication of polycrystalline CdTe-based solar cells and monolithic integration of photovoltaic devices into modules using laser scribing. We have improved the efficiency of sputtered superstrate type CdTe solar cells, including devices with unconventionally thin absorber, built world-record efficiency substrate type CdTe solar cells, observed effects related to interfacial layers, and investigated the use of 7 different types of lasers for scribing of materials used for CdTe and CuInGaSe2 solar cells. We have fabricated CdTe/CdS solar cells using magnetron sputtering with conversion efficiencies of 12.5%. As the thickness of CdTe is reduced to less than 1 mum, devices still maintain efficiencies near 10%. Thinning of the CdTe layer would make manufacturing of solar modules more economical. We have built inverted (substrate) configuration CdTe solar cells with state-of-the-art efficiencies of 7.8%. We find that tellurium and sulfur interdiffusion is strongly inhibited in substrate type cells due to the fact that the CdS is grown on fully formed CdTe grains. We have optimized a sputtering process for aluminum-doped ZnO, achieved a resistivity of 5 x 10-4 O-cm, and fabricated 5.8% efficient substrate type CdTe solar cells with the ZnO:Al top contact. We have researched the effect of a high resistivity (HR) layer between the CdS and a transparent conducting oxide. Cells with the HR layer maintain higher efficiencies as the thickness of the CdS is reduced to 60 nm and less. We have investigated the use of 7 different types of lasers for scribing of the polycrystalline materials used for CdTe and CuIn(Ga)Se2 (CIGS) thin-film solar cells. The lasers included four different Nd:YAG (532 and 1064 nm), a Cu vapor (511 and 578 nm) and two excimers (308 and 248 nm). Pulse durations ranged from 0.1 to 250 ns. We find that most wavelength and pulse duration combinations work well for the thin-film materials. ZnO should be scribed with an

  9. Solar Photovoltaic Cells.

    Science.gov (United States)

    Mickey, Charles D.

    1981-01-01

    Reviews information on solar radiation as an energy source. Discusses these topics: the key photovoltaic material; the bank theory of solids; conductors, semiconductors, and insulators; impurity semiconductors; solid-state photovoltaic cell operation; limitations on solar cell efficiency; silicon solar cells; cadmium sulfide/copper (I) sulfide…

  10. Prospects of novel front and back contacts for high efficiency cadmium telluride thin film solar cells from numerical analysis

    Energy Technology Data Exchange (ETDEWEB)

    Matin, M.A. [Department of Electrical, Electronic and System Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Department of Electrical and Electronics Engineering, Chittagong University of Engineering and Technology (CUET), Chittagong (Bangladesh); Mannir Aliyu, M.; Quadery, Abrar H. [Department of Electrical, Electronic and System Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Amin, Nowshad [Department of Electrical, Electronic and System Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Solar Energy Research Institute, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Center of Excellence for Research in Engineering Materials (CEREM), College of Engineering, King Saud University, Riyadh 11421 (Saudi Arabia)

    2010-09-15

    Cadmium telluride (CdTe) thin film solar cell has long been recognized as a leading photovoltaic candidate for its high efficiency and low cost. A numerical simulation has been performed using AMPS-1D simulator to explore the possibility of higher efficiency and stable CdS/CdTe cell among several cell structures with indium tin oxide (ITO) and cadmium stannate (Cd{sub 2}SnO{sub 4}) as front contact material, tin oxide (SnO{sub 2}), zinc oxide (ZnO) and zinc stannate (Zn{sub 2}SnO{sub 4}) as buffer layer, and silver (Ag) or antimony telluride (Sb{sub 2}Te{sub 3}) with molybdenum (Mo) or zinc telluride (ZnTe) with aluminium (Al) as back contact material. The cell structure ITO/i-ZnO/CdS/CdS{sub x}Te{sub 1-x}/CdTe/Ag has shown the best conversion efficiency of 16.9% (Voc=0.9 V, Jsc=26.35 mA/cm{sup 2}, FF=0.783). This analysis has shown that ITO as front contact material, ZnO as buffer layer and ZnTe or Sb{sub 2}Te{sub 3} back surface reflector (BSR) are suitable material system for high efficiency (>15%) and stable CdS/CdTe cells. The cell normalized efficiency linearly decreased at a temperature gradient of -0.25%/ C for ZnTe based cells, and at -0.40%/ C for other cells. (author)

  11. Non-Uniformities in Thin-Film Cadmium Telluride Solar Cells Using Electroluminescence and Photoluminescence: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Zaunbrecher, K.; Johnston, S.; Yan, F.; Sites, J.

    2011-07-01

    It is the purpose of this research to develop specific imaging techniques that have the potential to be fast, in-line tools for quality control in thin-film CdTe solar cells. Electroluminescence (EL) and photoluminescence (PL) are two techniques that are currently under investigation on CdTe small area devices made at Colorado State University. It is our hope to significantly advance the understanding of EL and PL measurements as applied to CdTe. Qualitative analysis of defects and non-uniformities is underway on CdTe using EL, PL, and other imaging techniques.

  12. High efficiency cadmium telluride and zinc telluride based thin-film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Rohatgi, A.; Sudharsanan, R.; Ringel, S.A.; Chou, H.C. (Georgia Inst. of Tech., Atlanta, GA (United States))

    1992-10-01

    This report describes work to improve the basic understanding of CdTe and ZnTe alloys by growing and characterizing these films along with cell fabrication. The major objective was to develop wide-band-gap (1.6--1.8 eV) material for the top cell, along with compatible window material and transparent ohmic contacts, so that a cascade cell design can be optimized. Front-wall solar cells were fabricated with a glass/SnO{sub 2}/CdS window, where the CdS film is thin to maximize transmission and current. Wide-band-gap absorber films (E{sub g} = 1.75 eV) were grown by molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD) techniques, which provided excellent control for tailoring the film composition and properties. CdZnTe films were grown by both MBE and MOCVD. All the as-grown films were characterized by several techniques (surface photovoltage spectroscopy, Auger electron spectroscopy (AES), and x-ray photoelectron spectroscopy (XPS)) for composition, bulk uniformity, thickness, and film and interface quality. Front-wall-type solar cells were fabricated in collaboration with Ametek Materials Research Laboratory using CdTe and CdZnTe polycrystalline absorber films. The effects of processing on ternary film were studied by AES and XPS coupled with capacitance voltage and current voltage measurements as a function of temperature. Bias-dependent spectral response and electrical measurements were used to test some models in order to identify and quantify dominant loss mechanisms.

  13. Development of copper sulfide/cadmium sulfide thin-film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Szedon, J.R.; Biter, W.J.; Abel, J.A.; Dickey, H.C.; Shirland, F.A.

    1981-02-27

    The purpose of this work has been to identify aspects of cell fabrication and treatment which are critical for achieving high efficiency Cu/sub 2/S/CdS solar cells. In approaching the problem several comparisons were made of the effects of specific steps in two methods of cell fabrication. These methods had previously given cells of about 6% and a maximum of 9% efficiency. Three areas requiring special attention and specific means to achieve acceptable results were identified. (1) The Cu/sub 2/S/CdS heterojunction area must be minimized. If single source evaporations of CdS are made on substrates whose temperatures (approx. 220/sup 0/C) are monitored and controlled using welded thermocouples, the CdS films will have adequately large grains (grain diameter greater than or equal to 2 ..mu..m) and will not develop significant etch pits during texturing in a mild etchant solution. (2) The termination of the wet barrier processing steps must be done carefully. An acceptable termination involves minimizing the amount of cuprous chloride retained on the cell surface during transfer to a rinsing stage while providing adequate exclusion of air from the space above the surface of the cuprous chloride solution. (3) Once formed, the Cu/sub 2/S layer should not be exposed to high temperatures (>100/sup 0/C) for long periods of time (> 5 min) if surface adsorbed moisture or oxygen are present. Heat treatments in ampoules under flowing hydrogen atmospheres should be preceded and followed by periods of at least 30 minutes at room temperature in the reducing ambient. If all these precautions are taken, wet chemical barrier processing of thermally evaporated CdS films on zinc-plated copper foil substrates yields cells of nearly 8% conversion efficiency without AR coating.

  14. Development of copper sulfide/cadmium sulfide thin-film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Szedon, J.R.; Biter, W.J.; Dickey, H.C.

    1982-03-01

    Unencapsulated thin-film solar cells of the Cu/sub 2/S/CdS type have been aged in controlled flowing-gas ambients to characterize changes in their photovoltaic properties. Severe degradation occurring in wet O/sub 2/ ambients at room temperature probably accounts for the large short-circuit current losses reported earlier. Limited loss (<15% of initial values) in J/sub sc/ occurs at RT in dry oxygen. No loss can be attributed to moisture in Ar or N/sub 2/ ambients for exposure times greater than approx. 2 hrs. Direct measurements of optical absorption in the front Cu/sub 2/S layer would be facilitated by an integral CdS/Cu/sub 2/S detector on the back surface. Several techniques for making such a detector were successfully demonstrated.

  15. Evolution of oxygenated cadmium sulfide (CdS:O) during high-temperature CdTe solar cell fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Meysing, Daniel M.; Reese, Matthew O.; Warren, Charles W.; Abbas, Ali; Burst, James M.; Mahabaduge, Hasitha P.; Metzger, Wyatt K.; Walls, John M.; Lonergan, Mark C.; Barnes, Teresa M.; Wolden, Colin A.

    2016-12-01

    Oxygenated cadmium sulfide (CdS:O) produced by reactive sputtering has emerged as a promising alternative to conventional CdS for use as the n-type window layer in CdTe solar cells. Here, complementary techniques are used to expose the window layer (CdS or CdS:O) in completed superstrate devices and combined with a suite of materials characterization to elucidate its evolution during high temperature device processing. During device fabrication amorphous CdS:O undergoes significant interdiffusion with CdTe and recrystallization, forming CdS1-yTey nanocrystals whose Te fraction approaches solubility limits. Significant oxygen remains after processing, concentrated in sulfate clusters dispersed among the CdS1-yTey alloy phase, accounting for ~30% of the post-processed window layer based on cross-sectional microscopy. Interdiffusion and recrystallization are observed in devices with un-oxygenated CdS, but to a much lesser extent. Etching experiments suggest that the CdS thickness is minimally changed during processing, but the CdS:O window layer is reduced from 100 nm to 60-80 nm, which is confirmed by microscopy. Alloying reduces the band gap of the CdS:O window layer to 2.15 eV, but reductions in thickness and areal density improve its transmission spectrum, which is well matched to device quantum efficiency. The changes to the window layer in the reactive environments of device fabrication are profoundly different than what occurs by thermal annealing in an inert environment, which produced films with a band gap of 2.4 eV for both CdS and CdS:O. These results illustrate for the first time the significant changes that occur to the window layer during processing that are critical to the performance of CdTe solar cells.

  16. Enhanced Performance of Nanoporous Titanium Dioxide Solar Cells Using Cadmium Sulfide and Poly(3-hexylthiophene Co-Sensitizers

    Directory of Open Access Journals (Sweden)

    Murugathas Thanihaichelvan

    2017-09-01

    Full Text Available This work reports the effect of co-sensitization of nanoporous titanium dioxide using Cadmium Sulfide (CdS and poly(3-hexylthiophene (P3HT on the performance of hybrid solar cells. CdS nanolayer with different thicknesses was grown on Titanium Dioxide (TiO2 nanoparticles by chemical bath deposition technique with varying deposition times. Both atomic force microscopy (AFM and UV–Vis–NIR spectroscopy measurements of TiO2 electrode sensitized with and without CdS layer confirm that the existence of CdS layer on TiO2 nanoparticles. AFM images of CdS-coated TiO2 nanoparticles show that the surface roughness of the TiO2 nanoparticle samples decreases with increasing CdS deposition times. Current density–voltage and external quantum efficiency (EQE measurements were carried out for corresponding solar cells. Both short circuit current density (JSC and fill factor were optimized at the CdS deposition time of 12 min. On the other hand, a steady and continuous increment in the open circuit voltage (VOC was observed with increasing CdS deposition time and increased up to 0.81 V when the deposition time was 24 min. This may be attributed to the increased gradual separation of P3HT and TiO2 phases and their isolation at the interfaces. The higher VOC of 0.81 V was due to the higher built-in voltage at the CdS–P3HT interface when compared to that at the TiO2–P3HT interface. Optimized nanoporous TiO2 solar cells with CdS and P3HT co-sensitizers showed external quantum efficiency (EQE of over 40% and 80% at the wavelengths corresponding to strong absorption of the polymer and CdS, respectively. The cells showed an overall average efficiency of over 2.4% under the illumination of 70 mW/cm2 at AM 1.5 condition.

  17. Occupational exposure to arsenic and cadmium in thin-film solar cell production.

    Science.gov (United States)

    Spinazzè, Andrea; Cattaneo, Andrea; Monticelli, Damiano; Recchia, Sandro; Rovelli, Sabrina; Fustinoni, Silvia; Cavallo, Domenico M

    2015-06-01

    Workers involved in the production of Cd/As-based photovoltaic modules may be routinely or accidentally exposed to As- or Cd-containing inorganic compounds. Workers' exposure to As and Cd was investigated by environmental monitoring following a worst-case approach and biological monitoring from the preparation of the working facility to its decommissioning. Workplace surface contamination was also evaluated through wipe-test sampling. The highest mean airborne concentrations were found during maintenance activities (As = 0.0068 µg m(-3); Cd = 7.66 µg m(-3)) and laboratory simulations (As = 0.0075 µg m(-3); Cd = 11.2 µg m(-3)). These types of operations were conducted for a limited time during a typical work shift and only in specifically suited containment areas, where the highest surface concentrations were also found (laboratory: As = 2.94 µg m(-2), Cd = 167 µg m(-2); powder containment booth: As = 4.35 µg m(-2), Cd = 1500 µg m(-2)). The As and Cd urinary levels (As_u; Cd_u) were not significantly different for exposed (As_u = 6.11±1.74 µg l(-1); Cd_u = 0.24±2.36 µg g(-1) creatinine) and unexposed workers (As_u = 6.11±1.75 µg l(-1); Cd_u = 0.22±2.08 µg g(-1) creatinine). Despite airborne arsenic and cadmium exposure well below the threshold limit value (TLV) when the operation is appropriately maintained in line, workers who are involved in various operations (maintenance, laboratory test) could potentially be at risk of significant exposure, well in excess of the TLV. Nevertheless, the biological monitoring data did not show significant occupationally related arsenic and cadmium intake in workers and no significant changes or differences in arsenic and cadmium urinary level among the exposed and unexposed workers were found. © The Author 2015. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

  18. An advanced space photovoltaic concentrator array using Fresnel lenses, gallium arsenide cells, and prismatic cell covers

    Science.gov (United States)

    O'Neill, Mark J.; Piszczor, Michael F.

    1988-01-01

    The current status of a space concentrator array which uses refractive optics, gallium arsenide cells, and prismatic cell covers to achieve excellent performance at a very low array mass is documented. The prismatically covered cells have established records for space cell performance (24.2 percent efficient at 100 AM0 suns and 25 C) and terrestrial single-junction cell performance (29.3 percent efficient at 200 AM1.5 suns and 25 C).

  19. High Efficiency Solar Panel. Phase II. Gallium Arsenide.

    Science.gov (United States)

    1981-03-01

    distance apartare lowered onto an interconnect/cell assembly with a calibrated force. Activation of an electrical switch introduces a voltage and current...the working area of the parallel gap Aelder is shown in Figure 8. Here two electrodes, a set distance apartare lowered onto an interconnect/cell

  20. Spectral analysis of the effects of 1.7 MeV electron irradiation on the current transfer characteristic of cadmium telluride solar cells.

    Science.gov (United States)

    Tian, Jin-Xiu; Zeng, Guang-Gen; He, Xu-Lin; Zhang, Jing-Quan; Wu, Li-Li; Li, Wei; Li, Bing; Wang, Wen-Wu; Feng, Liang-Huan

    2014-04-01

    The effects of device performance of 1.7 MeV electron irradiation on cadmium telluride polycrystalline thin film solar cells with the structure of anti-radiation glass/ITO/ZnO/CdS/CdTe/ZnTe/ZnTe : Cu/Ni have been studied. Light and dark I-V characteristics, dark C-V characteristics, quantum efficiency (QE), admittance spectrum (AS) and other testing methods were used to analyze cells performance such as the open-circuit voltage (Voc), short-circuit current (Isc), fill factor (FF) and conversion efficiency (eta). It was explored to find out the effects of irradiation on the current transfer characteristic of solar cells combined with the dark current density (Jo), diode ideal factor (A), quantum efficiency, carrier concentration and the depletion layer width. The decline in short-circuit current was very large and the efficiency of solar cells decreased obviously after irradiation. Reverse saturation current density increased, which indicates that p-n junction characteristics of solar cells were damaged, and diode ideal factor was almost the same, so current transport mechanism of solar cells has not changed. Quantum efficiency curves proved that the damage of solar cells' p-n junction influenced the collection of photo-generated carriers. Irradiation made carrier concentration reduce to 40.6%. The analyses have shown that. A new defect was induced by electron irradiation, whose position is close to 0.58 eV above the valence band in the forbidden band, and capture cross section is 1.78 x 10(-16) cm2. These results indicate that irradiation influences the generation of photo-generated carriers, increases the risk of the carrier recombination and the reverse dark current, and eventually makes the short-circuit current of solar cells decay.

  1. Modeling of High Efficiency Solar Cells Under Laser Pulse for Power Beaming Applications

    Science.gov (United States)

    Jain, Raj K.; Landis, Geoffrey A.

    1994-01-01

    Solar cells may be used as receivers for laser power beaming. To understand the behavior of solar cells when illuminated by a pulsed laser, the time response of gallium arsenide and silicon solar cells to pulsed monochromatic input has been modeled using a finite element solar cell model.

  2. Thin film cadmium telluride, zinc telluride, and mercury zinc telluride solar cells. Final subcontract report, 1 July 1988--31 December 1991

    Energy Technology Data Exchange (ETDEWEB)

    Chu, T.L. [University of South Florida, Tampa, FL (United States)

    1992-04-01

    This report describes research to demonstrate (1) thin film cadmium telluride solar cells with a quantum efficiency of 75% or higher at 0. 44 {mu}m and a photovoltaic efficiency of 11.5% or greater, and (2) thin film zinc telluride and mercury zinc telluride solar cells with a transparency to sub-band-gap radiation of 65% and a photovoltaic conversion efficiency of 5% and 8%, respectively. Work was directed at (1) depositing transparent conducting semiconductor films by solution growth and metal-organic chemical vapor deposition (MOCVD) technique, (2) depositing CdTe films by close-spaced sublimation (CSS) and MOCVD techniques, (3) preparing and evaluating thin film CdTe solar cells, and (4) preparing and characterizing thin film ZnTe, CD{sub 1-x}Zn{sub 1-x}Te, and Hg{sub 1-x}Zn{sub x}Te solar cells. The deposition of CdS films from aqueous solutions was investigated in detail, and their crystallographic, optical, and electrical properties were characterized. CdTe films were deposited from DMCd and DIPTe at 400{degrees}C using TEGa and AsH{sub 3} as dopants. CdTe films deposited by CSS had significantly better microstructures than those deposited by MOCVD. Deep energy states in CdTe films deposited by CSS and MOCVD were investigated. Thin films of ZnTe, Cd{sub 1- x}Zn{sub x}Te, and Hg{sub 1-x}Zn{sub x}Te were deposited by MOCVD, and their crystallographic, optical, and electrical properties were characterized. 67 refs.

  3. Properties of reactively sputtered oxygenated cadmium sulfide (CdS:O) and their impact on CdTe solar cell performance

    Energy Technology Data Exchange (ETDEWEB)

    Meysing, Daniel M., E-mail: dmeysing@mines.edu; Wolden, Colin A. [Chemical and Biological Engineering Department, Colorado School of Mines, 1613 Illinois St., Golden, Colorado 80401 (United States); Griffith, Michelle M. [Department of Physics, Colorado School of Mines, 1523 Illinois St., Golden, Colorado 80401 (United States); Mahabaduge, Hasitha; Pankow, Joel; Reese, Matthew O.; Burst, James M.; Rance, William L.; Barnes, Teresa M. [National Renewable Energy Laboratory, 15013 Denver West Pkwy., Golden, Colorado 80401 (United States)

    2015-03-15

    Oxygenated cadmium sulfide (CdS:O) is commonly used as the n-type window layer in high-performance CdTe heterojunction solar cells. This layer is deposited by reactive sputtering, but the optimal amount of oxygen in the sputtering ambient is highly dependent on the specific system and process employed. In this work, the intrinsic properties of CdS:O were measured as a function of the oxygen content (0%–10%) in the sputtering ambient and correlated to device performance with the goal of better defining optimal CdS:O properties for CdTe solar cells. Optimal performance was found using CdS:O films that contained ∼40 at. % oxygen as measured by Rutherford backscattering spectrometry. X-ray photoelectron spectroscopy confirmed these results and showed that oxygen is incorporated primarily as oxygenated sulfur compounds (SO{sub x}). Device efficiency improved from 10.5% using CdS to >14% with CdS:O due largely to increases in short-circuit current density as well as a modest improvement in open-circuit voltage. The transparency of the CdS:O films was well correlated with observed improvements in blue quantum efficiency with increasing oxygen content. The optical bandgap of as-deposited CdS:O was identified as a simple metric for process optimization and transfer, with 2.8 eV being ideal for the device architecture employed.

  4. Polycrystalline thin film cadmium telluride solar cells fabricated by electrodeposition. Annual technical report, 20 March 1995--19 March 1996

    Energy Technology Data Exchange (ETDEWEB)

    Trefny, J U; Mao, D [Colorado School of Mines, Golden, CO (United States)

    1997-04-01

    The objective of this project is to develop improved processes for fabricating CdTe/CdS polycrystalline thin-film solar cells. Researchers used electrodeposition to form CdTe; electrodeposition is a non-vacuum, low-cost technique that is attractive for economic, large-scale production. During the past year, research and development efforts focused on several steps that are most critical to the fabricating high-efficiency CdTe solar cells. These include the optimization of the CdTe electrodeposition process, the effect of pretreatment of CdS substrates, the post-deposition annealing of CdTe, and back-contact formation using Cu-doped ZnTe. Systematic investigations of these processing steps have led to a better understanding and improved performance of the CdTe-based cells. Researchers studied the structural properties of chemical-bath-deposited CdS thin films and their growth mechanisms by investigating CdS samples prepared at different deposition times; investigated the effect of CdCl{sub 2} treatment of CdS films on the photovoltaic performance of CdTe solar cells; studied Cu-doped ZnTe as a promising material for forming stable, low-resistance contacts to the p-type CdTe; and investigated the effect of CdTe and CdS thickness on the photovoltaic performance of the resulting cells. As a result of their systematic investigation and optimization of the processing conditions, researchers improved the efficiency of CdTe/CdS cells using ZnTe back-contact and electrodeposited CdTe. The best CdTe/CdS cell exhibited a V{sub oc} of 0.778 V, a J{sub sc} of 22.4 mA/cm{sup 2}, a FF of 74%, and an efficiency of 12.9% (verified at NREL). In terms of individual parameters, researchers obtained a V{sub oc} over 0.8 V and a FF of 76% on other cells.

  5. Solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Tsukamoto, Moriaki; Hayashibara, Mitsuo

    1988-08-18

    Concerning the exsisting solar cell utilizing wavelength transition, the area of the solar cell element necessary for unit electric power output can be made small, but transition efficiency of the solar cell as a whole including a plastic plate with phosphor is not high. This invention concerns a solar cell which is appropriate for transferring the light within a wide spectrum range of the sunlight to electricilty efficiently, utilizes wavelength transition and has high efficiency per unit area. In other words, the solar cell of this invention has the feature of providing in parallel with a photoelectric transfer layer a layer of wavelength transitioning material (phosphor) which absorbs the light within the range of wavelength of low photoelectric transfer efficiency at the photoelectric transfer layer and emits the light within the range of wavelength in which the photoelectric transfer rate is high on the light incident side of the photoelectric transfer layer. (5 figs)

  6. Solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Yoshiyuki.

    1989-07-06

    In this invention, in a solar cell which has an electrode consisting of a superconductor, the superconductor electrode is partly or entirely covered with a metal or light reflecting material. In the above, the pattern on the substrate at the junction of the electrode and the semiconductor is the same as that of a comb-type electrode formed at the top of the semiconductor. By this, a solar cell was provided wherein a superconductive electrode which is not subject to degradation of the superconductive characteristics even in the light of high intensity, operating stably at high efficiency, indicating very high practical effect. In addition to the use of amorphous silicon as a semiconductor of the soalr cell, such other material as Si-single crystal, Ge and Ge/As can be used. For the superconductor electrode, such other material as YBaCuO can also be used. 2 figs.

  7. Inhalation developmental toxicology studies: Gallium arsenide in mice and rats

    Energy Technology Data Exchange (ETDEWEB)

    Mast, T.J.; Greenspan, B.J.; Dill, J.A.; Stoney, K.H.; Evanoff, J.J.; Rommereim, R.L.

    1990-12-01

    Gallium arsenide is a crystalline compound used extensively in the semiconductor industry. Workers preparing solar cells and gallium arsenide ingots and wafers are potentially at risk from the inhalation of gallium arsenide dust. The potential for gallium arsenide to cause developmental toxicity was assessed in Sprague- Dawley rats and CD-1 (Swiss) mice exposed to 0, 10, 37, or 75 mg/m{sup 3} gallium arsenide, 6 h/day, 7 days/week. Each of the four treatment groups consisted of 10 virgin females (for comparison), and {approx}30 positively mated rats or {approx}24 positively mated mice. Mice were exposed on 4--17 days of gestation (dg), and rats on 4--19 dg. The day of plug or sperm detection was designated as 0 dg. Body weights were obtained throughout the study period, and uterine and fetal body weights were obtained at sacrifice (rats, 20 dg; mice, 18 dg). Implants were enumerated and their status recorded. Live fetuses were sexed and examined for gross, visceral, skeletal, and soft-tissue craniofacial defects. Gallium and arsenic concentrations were determined in the maternal blood and uterine contents of the rats (3/group) at 7, 14, and 20 dg. 37 refs., 11 figs., 30 tabs.

  8. Enhancing Solar Cell Efficiency Using Photon Upconversion Materials

    Science.gov (United States)

    Shang, Yunfei; Hao, Shuwei; Yang, Chunhui; Chen, Guanying

    2015-01-01

    Photovoltaic cells are able to convert sunlight into electricity, providing enough of the most abundant and cleanest energy to cover our energy needs. However, the efficiency of current photovoltaics is significantly impeded by the transmission loss of sub-band-gap photons. Photon upconversion is a promising route to circumvent this problem by converting these transmitted sub-band-gap photons into above-band-gap light, where solar cells typically have high quantum efficiency. Here, we summarize recent progress on varying types of efficient upconversion materials as well as their outstanding uses in a series of solar cells, including silicon solar cells (crystalline and amorphous), gallium arsenide (GaAs) solar cells, dye-sensitized solar cells, and other types of solar cells. The challenge and prospect of upconversion materials for photovoltaic applications are also discussed. PMID:28347095

  9. 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.

  10. 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 ...

  11. Quantum mechanical effects analysis of nanostructured solar cell models

    Directory of Open Access Journals (Sweden)

    Badea Andrei

    2016-01-01

    Full Text Available The quantum mechanical effects resulted from the inclusion of nanostructures, represented by quantum wells and quantum dots, in the i-layer of an intermediate band solar cell will be analyzed. We will discuss the role of these specific nanostructures in the increasing of the solar cells efficiency. InAs quantum wells being placed in the i-layer of a gallium arsenide (GaAs p-i-n cell, we will analyze the quantum confined regions and determine the properties of the eigenstates located therein. Also, we simulate the electroluminescence that occurs due to the nanostructured regions.

  12. The AMOS cell - An improved metal-semiconductor solar cell. [Antireflection coated Metal Oxide Semiconductor

    Science.gov (United States)

    Stirn, R. J.; Yeh, Y.-C. M.

    1975-01-01

    A new fabrication process is being developed which significantly improves the efficiency of metal-semiconductor solar cells. The resultant effect, a marked increase in the open-circuit voltage, is produced by the addition of an interfacial layer oxide on the semiconductor. Cells using gold on n-type gallium arsenide have been made in small areas (0.17 sq cm) with conversion efficiencies of 15% in terrestrial sunlight.

  13. 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.

  14. A strategy to improve the energy conversion efficiency and stability of quantum dot-sensitized solar cells using manganese-doped cadmium sulfide quantum dots.

    Science.gov (United States)

    Gopi, Chandu V V M; Venkata-Haritha, M; Kim, Soo-Kyoung; Kim, Hee-Je

    2015-01-14

    This article describes the effect of manganese (Mn) doping in CdS to improve the photovoltaic performance of quantum dot sensitized solar cells (QDSSCs). The performances of the QDSSCs are examined in detail using a polysulfide electrolyte with a copper sulfide (CuS) counter electrode. Under the illumination of one sun (AM 1.5 G, 100 mW cm(-2)), 10 molar% Mn-doped CdS QDSSCs exhibit a power conversion efficiency (η) of 2.85%, which is higher than the value of 2.11% obtained with bare CdS. The improved photovoltaic performance is due to the impurities from Mn(2+) doping of CdS, which have an impact on the structure of the host material and decrease the surface roughness. The surface roughness and morphology of Mn-doped CdS nanoparticles can be characterised from atomic force microscopy images. Furthermore, the cell device based on the Mn-CdS electrode shows superior stability in the sulfide/polysulfide electrolyte in a working state for over 10 h, resulting in a highly reproducible performance, which is a serious challenge for the Mn-doped solar cell. Our finding provides an effective method for the fabrication of Mn-doped CdS QDs, which can pave the way to further improve the efficiency of future QDSSCs.

  15. Mutagenic effect of cadmium on tetranucleotide repeats in human cells

    Energy Technology Data Exchange (ETDEWEB)

    Slebos, Robbert J.C. [Department of Cancer Biology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN 37232 (United States) and Department of Otolaryngology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN 37232 (United States)]. E-mail: r.slebos@vanderbilt.edu; Li Ming [Department of Biostatistics, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN 37232 (United States); Evjen, Amy N. [Department of Cancer Biology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN 37232 (United States); Coffa, Jordy [Department of Cancer Biology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN 37232 (United States); Shyr, Yu [Department of Biostatistics, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN 37232 (United States); Yarbrough, Wendell G. [Department of Cancer Biology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN 37232 (United States); Department of Otolaryngology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN 37232 (United States)

    2006-12-01

    Cadmium is a human carcinogen that affects cell proliferation, apoptosis and DNA repair processes that are all important to carcinogenesis. We previously demonstrated that cadmium inhibits DNA mismatch repair (MMR) in yeast cells and in human cell-free extracts (H.W. Jin, A.B. Clark, R.J.C. Slebos, H. Al-Refai, J.A. Taylor, T.A. Kunkel, M.A. Resnick, D.A. Gordenin, Cadmium is a mutagen that acts by inhibiting mismatch repair, Nat. Genet. 34 (3) (2003) 326-329), but cadmium also inhibits DNA excision repair. For this study, we selected a panel of three hypermutable tetranucleotide markers (MycL1, D7S1482 and DXS981) and studied their suitability as readout for the mutagenic effects of cadmium. We used a clonal derivative of the human fibrosarcoma cell line HT1080 to assess mutation levels in microsatellites after cadmium and/or N-methyl-N-nitro-N-nitrosoguanidine (MNNG) exposure to study effects of cadmium in the presence or absence of base damage. Mutations were measured in clonally expanded cells obtained by limiting dilution after exposure to zero dose, 0.5 {mu}M cadmium, 5 nM MNNG or a combination of 0.5 {mu}M cadmium and 5 nM MNNG. Exposure of HT1080-C1 to cadmium led to statistically significant increases in microsatellite mutations, either with or without concurrent exposure to MNNG. A majority of the observed mutant molecules involved 4-nucleotide shifts consistent with DNA slippage mutations that are normally repaired by MMR. These results provide evidence for the mutagenic effects of low, environmentally relevant levels of cadmium in intact human cells and suggest that inhibition of DNA repair is involved.

  16. Nanostructured Organic Solar Cells

    DEFF Research Database (Denmark)

    Radziwon, Michal Jędrzej; Rubahn, Horst-Günter; Madsen, Morten

    Recent forecasts for alternative energy generation predict emerging importance of supporting state of art photovoltaic solar cells with their organic equivalents. Despite their significantly lower efficiency, number of application niches are suitable for organic solar cells. This work reveals...... the principles of bulk heterojunction organic solar cells fabrication as well as summarises major differences in physics of their operation....

  17. PEROVSKITE SOLAR CELLS (REVIEW ARTICLE)

    OpenAIRE

    Benli, Deniz

    2015-01-01

    A solar cell is a device that converts sunlight into electricity. There are different types of solar cells but this report mainly focuses on a type of new generation solar cell that has the name organo-metal halide perovskite, shortly perovskite solar cells. In this respect, the efficiency of power conversion is taken into account to replace the dominancy of traditional and second generation solar cell fields by perovskite solar cells. Perovskite solar cell is a type of solar cell including a...

  18. 31% European InGaP/GaAs/InGaAs Solar Cells for Space Application

    Directory of Open Access Journals (Sweden)

    Campesato Roberta

    2017-01-01

    Full Text Available We report a triple junction InGaP/GaAs/InGaNAs solar cell with efficiency of ~31% at AM0, 25 °C fabricated using a combined molecular beam epitaxy (MBE and metal-organic chemical vapour deposition (MOCVD processes. The prototype cells comprise of InGaNAs (Indium Gallium Nitride Arsenide bottom junction grown on a GaAs (Gallium Arsenide substrate by MBE and middle and top junctions deposited by MOCVD. Repeatable cell characteristics and uniform efficiency pattern over 4-inch wafers were obtained. Combining the advantages offered by MBE and MOCVD opens a new perspective for fabrication of high-efficiency space tandem solar cells with three or more junctions. Results of radiation resistance of the sub-cells are also presented and critically evaluated to achieve high efficiency in EOL conditions.

  19. Polycrystalline thin-film cadmium telluride solar cells fabricated by electrodeposition. Annual subcontract report, 20 March 1992--19 March 1993

    Energy Technology Data Exchange (ETDEWEB)

    Trefny, J.U.; Furtak, T.E.; Wada, N.; Williamson, D.L.; Kim, D. [Colorado School of Mines, Golden, CO (US)

    1993-08-01

    This report describes progress during the first year of a 3-year program at Colorado School of Mines, based upon earlier studies performed by Ametek Corporation, to develop specific layers of the Ametek n-i-p structure as well as additional studies of several transparent conducting oxides. Thin films of ZnO and ZnO:Al were deposited under various conditions. For the n-layer of the Ametek structure, a dip-coating method was developed for the deposition of CdS films. The authors also present data on the characterization of these films by X-ray diffraction, Raman spectroscopy, scanning tunneling microscopy, small-angle X-ray scattering, and other techniques. They made progress in the electrodeposition of the CdTe i-layer of the Ametek structure. They developed appropriate electrochemical baths and are beginning to understand the role of the many experimental parameters that must be controlled to obtain high-quality films of this material. They explored the possibility of using an electrochemical process for fabricating the ZnTe p-layer. Some preliminary success was achieved, and this step will be pursued in the next phase. Finally, they fabricated a number of ``dot`` solar cells with the structure glass/SnO{sub 2}/CdS/CdTe/Au. Several cells with efficiencies in the range of 5%-6% were obtained, and they are confident, given recent progress, that cells with efficiencies in excess of 10% will be achieved in the near future.

  20. Cadmium

    NARCIS (Netherlands)

    Meulenbelt, Jan

    2017-01-01

    Together with zinc and mercury, cadmium belongs to group IIb of the periodic table. It can be found in rocks, soil, water, coal, zinc ore, lead ore, and copper ore. In the environment, cadmium is present predominantly as the oxide or as the chloride, sulfide, or sulfate salt. It has no recognizable

  1. 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.

  2. Photovoltaic solar cell

    Science.gov (United States)

    Nielson, Gregory N.; Gupta, Vipin P.; Okandan, Murat; Watts, Michael R.

    2015-09-08

    A photovoltaic solar concentrator is disclosed with one or more transverse-junction solar cells (also termed point contact solar cells) and a lens located above each solar cell to concentrate sunlight onto the solar cell to generate electricity. Piezoelectric actuators tilt or translate each lens to track the sun using a feedback-control circuit which senses the electricity generated by one or more of the solar cells. The piezoelectric actuators can be coupled through a displacement-multiplier linkage to provide an increased range of movement of each lens. Each lens in the solar concentrator can be supported on a frame (also termed a tilt plate) having three legs, with the movement of the legs being controlled by the piezoelectric actuators.

  3. A novel three-jet microreactor for localized metal-organic chemical vapour deposition of gallium arsenide : Design and simulation

    NARCIS (Netherlands)

    Konakov, S.A.; Krzhizhanovskaya, V.V.

    2016-01-01

    We present a novel three-jet microreactor design for localized deposition of gallium arsenide (GaAs) by low-pressure Metal-Organic Chemical Vapour Deposition (MOCVD) for semiconductor devices, microelectronics and solar cells. Our approach is advantageous compared to the standard lithography and

  4. 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.

  5. Efficiency Enhancement of Gallium Arsenide Photovoltaics Using Solution-Processed Zinc Oxide Nanoparticle Light Scattering Layers

    Directory of Open Access Journals (Sweden)

    Yangsen Kang

    2015-01-01

    Full Text Available We demonstrate a high-throughput, solution-based process for subwavelength surface texturing of a III-V compound solar cell. A zinc oxide (ZnO nanoparticle ink is spray-coated directly on top of a gallium arsenide (GaAs solar cell. The nanostructured ZnO films have demonstrated antireflection and light scattering properties over the visible/near-infrared (NIR spectrum. The results show a broadband spectral enhancement of the solar cell external quantum efficiency (EQE, a 16% enhancement of short circuit current, and a 10% increase in photovoltaic efficiency.

  6. Solar cell. Taiyo denchi

    Energy Technology Data Exchange (ETDEWEB)

    Mitsui, K.; Shitsutani, T. (Mitsubishi electric Corp., Tokyo (Japan))

    1991-09-10

    This invention provides a highly efficient soalr cell which requires no accurate conformity of collector electrodes, especially a highly efficient tandem solar cell. This invention comprises a collector electrode placed in an effective light receiving zone on the surface of the 2nd electroconductive semiconductor layer formed on the 1st electroconductive semiconductor substrate, the 1st electrode placed in the periphery of light receiving zone and comprising a common electrode connected to the above-mentioned collector electrode, and the 2nd electrode formed on the back side of above-mentioned semiconductor substrate in zones except the zone facing the effective light-receiving zone. In case of using as a tandem solar cell, the above-mentioned solar cell is used as the 1st solar cell, and, as the 2nd solar cell which is incidented by solar light which passed through it, a solar cell having no electrode is used on the surface which faces the 1st solar cell. 4 figs.

  7. Laser and electron beam processing of silicon and gallium arsenide

    Energy Technology Data Exchange (ETDEWEB)

    Narayan, J.

    1979-10-01

    Laser (photon) and electron beams provide a controlled source of heat by which surface layers of silicon and gallium arsenide can be rapidly melted and cooled with rates exceeding 10/sup 80/C/sec. The melting process has been used to remove displacement damage in ion implanted Si and GaAs, to remove dislocations, loops and precipitates in silicon and to study impurity segregation and solubility limits. The mechanisms associated with various phenomena will be examined. The possible impact of laser and electron beam processing on device technology, particularly with respect to solar cells is discussed.

  8. Rectenna solar cells

    CERN Document Server

    Moddel, Garret

    2013-01-01

    Rectenna Solar Cells discusses antenna-coupled diode solar cells, an emerging technology that has the potential to provide ultra-high efficiency, low-cost solar energy conversion. This book will provide an overview of solar rectennas, and provide thorough descriptions of the two main components: the diode, and the optical antenna. The editors discuss the science, design, modeling, and manufacturing of the antennas coupled with the diodes. The book will provide concepts to understanding the challenges, fabrication technologies, and materials required to develop rectenna structures. Written by e

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-07-31

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

  10. Dye Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Di Wei

    2010-03-01

    Full Text Available Dye sensitized solar cell (DSSC is the only solar cell that can offer both the flexibility and transparency. Its efficiency is comparable to amorphous silicon solar cells but with a much lower cost. This review not only covers the fundamentals of DSSC but also the related cutting-edge research and its development for industrial applications. Most recent research topics on DSSC, for example, applications of nanostructured TiO2, ZnO electrodes, ionic liquid electrolytes, carbon nanotubes, graphene and solid state DSSC have all been included and discussed.

  11. Quantum dot solar cells

    CERN Document Server

    Wu, Jiang

    2013-01-01

    The third generation of solar cells includes those based on semiconductor quantum dots. This sophisticated technology applies nanotechnology and quantum mechanics theory to enhance the performance of ordinary solar cells. Although a practical application of quantum dot solar cells has yet to be achieved, a large number of theoretical calculations and experimental studies have confirmed the potential for meeting the requirement for ultra-high conversion efficiency. In this book, high-profile scientists have contributed tutorial chapters that outline the methods used in and the results of variou

  12. Nanostructured inorganic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Musselman, Kevin P. [Cambridge Univ. (United Kingdom). Dept. of Physics; Schmidt-Mende, Lukas [Ludwig-Maximilians Univ. Muenchen (DE). Dept. of Physics and Center for NanoScience (CeNS)

    2011-07-01

    Recent progress in the development of nanostructured inorganic solar cells is reviewed. Nanostructuring of inorganic solar cells offers the possibility of reducing the cost of photovoltaics by allowing smaller amounts of lower-grade photovoltaic semiconductors to be used. Various fabrication methods used to nanostructure traditional photovoltaic semiconductors are detailed and the performance of resulting devices is discussed. The synthesis of solar cells by solution-based methods using less traditional, abundant materials is identified as a promising route to widescale photovoltaic electricity generation, and nanostructured solar cell geometries are highlighted as essential in this approach. Templating and self-assembling methods used to produce appropriate low-cost nanostructures from solutions are detailed, and the performance of preliminary ultra-low-cost cells made with these structures is reviewed. (orig.)

  13. Solar cell radiation handbook

    Science.gov (United States)

    Tada, H. Y.; Carter, J. R., Jr.; Anspaugh, B. E.; Downing, R. G.

    1982-01-01

    The handbook to predict the degradation of solar cell electrical performance in any given space radiation environment is presented. Solar cell theory, cell manufacturing and how they are modeled mathematically are described. The interaction of energetic charged particles radiation with solar cells is discussed and the concept of 1 MeV equivalent electron fluence is introduced. The space radiation environment is described and methods of calculating equivalent fluences for the space environment are developed. A computer program was written to perform the equivalent fluence calculations and a FORTRAN listing of the program is included. Data detailing the degradation of solar cell electrical parameters as a function of 1 MeV electron fluence are presented.

  14. Temperature Effect of Electrical Properties of Cigs Solar Cell ...

    African Journals Online (AJOL)

    In this paper we are interested in studying the copper–indium–gallium–selenium (CIGS) solar cells sandwiched between cadmium sulfide (CdS) and ZnO as buffer layers, and Molybdenum (Mo). Thus, we report our simulation results using the capacitance simulator (SCAPS) in terms of layer thickness, absorber layer band ...

  15. A membrane electrode assembled photoelectrochemical cell with a solar-responsive cadmium sulfide-zinc sulfide-titanium dioxide/mesoporous silica photoanode

    Science.gov (United States)

    Chen, Ming; Chen, Rong; Zhu, Xun; Liao, Qiang; An, Liang; Ye, Dingding; Zhou, Yuan; He, Xuefeng; Zhang, Wei

    2017-12-01

    In this work, a membrane electrode assembled photoelectrochemical cell (PEC) is developed for the electricity generation by degrading the organic compounds. The photocatalyst is prepared by the incorporation of mesoporous silica SBA-15 into TiO2 and the photosensitization of CdS-ZnS to enhance the photoanode performance, while the cathode employs the air-breathing mode to enhance the oxygen transport. The experimental results show that the developed PEC exhibits good photoresponse to the illumination and the appropriate SBA-15 mass ratio in the photoanode enables the enhancement of the performance. It is also shown that the developed PEC yields better performance in the alkaline environment than that in the neutral environment. Increasing the KOH concentration can improve the cell performance. There exist optimal liquid flow rate and organics concentration leading to the best performance. Besides, it is found that increasing the light intensity can generate more electron-hole pairs and thus enhance the cell performance. These results are helpful for optimizing the design.

  16. Photovoltaic solar cell

    Science.gov (United States)

    Nielson, Gregory N; Okandan, Murat; Cruz-Campa, Jose Luis; Resnick, Paul J

    2013-11-26

    A photovoltaic solar cell for generating electricity from sunlight is disclosed. The photovoltaic solar cell comprises a plurality of spaced-apart point contact junctions formed in a semiconductor body to receive the sunlight and generate the electicity therefrom, the plurality of spaced-apart point contact junctions having a first plurality of regions having a first doping type and a second plurality of regions having a second doping type. In addition, the photovoltaic solar cell comprises a first electrical contact electrically connected to each of the first plurality of regions and a second electrical contact electrically connected to each of the second plurality of regions, as well as a passivation layer covering major surfaces and sidewalls of the photovoltaic solar cell.

  17. Photovoltaic solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Nielson, Gregory N; Cruz-Campa, Jose Luis; Okandan, Murat; Resnick, Paul J

    2014-05-20

    A photovoltaic solar cell for generating electricity from sunlight is disclosed. The photovoltaic solar cell comprises a plurality of spaced-apart point contact junctions formed in a semiconductor body to receive the sunlight and generate the electricity therefrom, the plurality of spaced-apart point contact junctions having a first plurality of regions having a first doping type and a second plurality of regions having a second doping type. In addition, the photovoltaic solar cell comprises a first electrical contact electrically connected to each of the first plurality of regions and a second electrical contact electrically connected to each of the second plurality of regions, as well as a passivation layer covering major surfaces and sidewalls of the photovoltaic solar cell.

  18. Nanocrystal Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Gur, Ilan [Univ. of California, Berkeley, CA (United States)

    2006-01-01

    This dissertation presents the results of a research agenda aimed at improving integration and stability in nanocrystal-based solar cells through advances in active materials and device architectures. The introduction of 3-dimensional nanocrystals illustrates the potential for improving transport and percolation in hybrid solar cells and enables novel fabrication methods for optimizing integration in these systems. Fabricating cells by sequential deposition allows for solution-based assembly of hybrid composites with controlled and well-characterized dispersion and electrode contact. Hyperbranched nanocrystals emerge as a nearly ideal building block for hybrid cells, allowing the controlled morphologies targeted by templated approaches to be achieved in an easily fabricated solution-cast device. In addition to offering practical benefits to device processing, these approaches offer fundamental insight into the operation of hybrid solar cells, shedding light on key phenomena such as the roles of electrode-contact and percolation behavior in these cells. Finally, all-inorganic nanocrystal solar cells are presented as a wholly new cell concept, illustrating that donor-acceptor charge transfer and directed carrier diffusion can be utilized in a system with no organic components, and that nanocrystals may act as building blocks for efficient, stable, and low-cost thin-film solar cells.

  19. A Model of Cadmium Uptake and Transport in Caco-2 Cells.

    Science.gov (United States)

    Gerasimenko, T N; Senyavina, N V; Anisimov, N U; Tonevitskaya, S A

    2016-05-01

    We created a physiologically substantiated kinetic model of cadmium transport and toxicity in intestinal cell model (Caco-2 cells). Transcriptome profiling of Caco-2 cells revealed high content of transporter DMT1 and ZIP14 and intensive expression of some calcium channels of the CACN family. The mathematical model describing three types of transporters, as well as intracellular cadmium binding with metallothionein and excretion through the basolateral membrane allowed us to construct cadmium uptake and transport curves that approximated the previously obtained experimental data. Using the proposed model, we determined toxic intracellular cadmium concentration leading to cell death and impairing the integrity of cell monolayer and described cadmium transport in this case.

  20. Polymer Substrates For Lightweight, Thin-Film Solar Cells

    Science.gov (United States)

    Lewis, Carol R.

    1993-01-01

    Substrates survive high deposition temperatures. High-temperature-resistant polymers candidate materials for use as substrates of lightweight, flexible, radiation-resistant solar photovoltaic cells. According to proposal, thin films of copper indium diselenide or cadmium telluride deposited on substrates to serve as active semiconductor layers of cells, parts of photovoltaic power arrays having exceptionally high power-to-weight ratios. Flexibility of cells exploited to make arrays rolled up for storage.

  1. Characterization of solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Haerkoenen, J.; Tuominen, E.; Nybergh, K.; Ezer, Y.; Yli-Koski, M.; Sinkkonen, J. [Helsinki Univ. of Technology, Otaniemi (Finland). Dept. of Electrical and Communications Engineering

    1998-10-01

    Photovoltaic research in the Electron Physics Laboratory started in 1993, when laboratory joined the national TEKES/NEMO 2 research program. Since the beginning of the project, characterization as well as experimentally orientated development of the fabrication process of the solar cells were carried out parallery. The process development research started by the initiatives of the Finnish industry. At the moment a large amount of the laboratory personnel works on solar cell research and the financing comes mainly from external projects. The funding for the research has come from TEKES, Ministry of Education, Finnish Academy, GETA graduate school, special equipment grants of the university, and from the laboratory

  2. Nature's Solar Cell

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 2. Nature's Solar Cell. Stephen Suresh Gautham Nadig. Research News Volume 1 Issue 2 February 1996 pp 102-104. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/001/02/0102-0104 ...

  3. NASA Facts, Solar Cells.

    Science.gov (United States)

    National Aeronautics and Space Administration, Washington, DC.

    The design and function of solar cells as a source of electrical power for unmanned space vehicles is described in this pamphlet written for high school physical science students. The pamphlet is one of the NASA Facts Science Series (each of which consists of four pages) and is designed to fit in the standard size three-ring notebook. Review…

  4. Characterization of solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Haerkoenen, J.; Tuominen, E.; Nybergh, K.; Ezer, Y.; Yli-Koski, M.; Sinkkonen, J. [Helsinki Univ. of Technology (Finland). Dept. of Electrical and Communications Engineering

    1998-12-31

    Photovoltaic research began at the Electron Physics Laboratory of the Helsinki University of Tehnology in 1993, when the laboratory joined the national NEMO 2 research program. During the early stages of the photovoltaic research the main objective was to establish necessary measurement and characterisation routines, as well as to develop the fabrication process. The fabrication process development work has been supported by characterisation and theoretical modelling of the solar cells. Theoretical investigations have been concerned with systematic studies of solar cell parameters, such as diffusion lengths, surface recombination velocities and junction depths. The main result of the modelling and characterisation work is a method which is based on a Laplace transform of the so-called spatial collection efficiency function of the cell. The basic objective of the research has been to develop a fabrication process cheap enough to be suitable for commercial production

  5. A 15% efficient antireflection-coated metal-oxide-semiconductor solar cell

    Science.gov (United States)

    Stirn, R. J.; Yeh, Y. C. M.

    1975-01-01

    A new effect is being developed which significantly improves the conversion efficiency of antireflection-coated metal-oxide-semiconductor (AMOS) solar cells. The effect, a marked increase in the open-circuit voltage, is produced by the addition of an oxide layer to the semiconductor. Cells using gold on n-type gallium arsenide have been made with efficiencies up to 15% in terrestrial sunlight. All processing steps are amenable to the use of low-cost polycrystalline films of GaAs in place of the single crystals now used.

  6. Development of high band gap materials for tandem solar cells and simulation studies on mechanical tandem solar cells

    Science.gov (United States)

    Vijayakumar, Vishnuvardhanan

    the various theoretical and practical loss mechanisms in tandem devices. Two configurations were evaluated, first was silicon / germanium tandem cell and the second was gallium arsenide / silicon tandem cell. The simulation models were validated by their close match to the performance of experimental standalone solar cells devices reported in the literature. Finally the efficiency limits of the present generation of high band gap solar cells were discussed. Voltage and current loss of the high band gap solar cells were compared with present generation silicon solar cells and challenges in improving their efficiencies were described.

  7. EDITORIAL: Nanostructured solar cells Nanostructured solar cells

    Science.gov (United States)

    Greenham, Neil C.; Grätzel, Michael

    2008-10-01

    Conversion into electrical power of even a small fraction of the solar radiation incident on the Earth's surface has the potential to satisfy the world's energy demands without generating CO2 emissions. Current photovoltaic technology is not yet fulfilling this promise, largely due to the high cost of the electricity produced. Although the challenges of storage and distribution should not be underestimated, a major bottleneck lies in the photovoltaic devices themselves. Improving efficiency is part of the solution, but diminishing returns in that area mean that reducing the manufacturing cost is absolutely vital, whilst still retaining good efficiencies and device lifetimes. Solution-processible materials, e.g. organic molecules, conjugated polymers and semiconductor nanoparticles, offer new routes to the low-cost production of solar cells. The challenge here is that absorbing light in an organic material produces a coulombically bound exciton that requires dissociation at a donor-acceptor heterojunction. A thickness of at least 100 nm is required to absorb the incident light, but excitons only diffuse a few nanometres before decaying. The problem is therefore intrinsically at the nano-scale: we need composite devices with a large area of internal donor-acceptor interface, but where each carrier has a pathway to the respective electrode. Dye-sensitized and bulk heterojunction cells have nanostructures which approach this challenge in different ways, and leading research in this area is described in many of the articles in this special issue. This issue is not restricted to organic or dye-sensitized photovoltaics, since nanotechnology can also play an important role in devices based on more conventional inorganic materials. In these materials, the electronic properties can be controlled, tuned and in some cases completely changed by nanoscale confinement. Also, the techniques of nanoscience are the natural ones for investigating the localized states, particularly at

  8. Solar cell. Taiyo denchi

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Hideo; Sato, Katsumi; Hokuyo, Shigeru.

    1989-08-09

    In the conventional soalr cell, adhesives flow out to outside of the interconnector before it cures when the glass covers are fitted, causing the stress relief part going out of function; this results in the damage of the cell, the expansion of the distance between the cells at assembling, which means a trend for larger size of the cell. This is especially a demerit when mounted onto the artificial satellite. This invention aims to prevent the break of the elements and the interconnectors by making the assembled unit smaller. In other words, it contains a solar cell element having electrodes on a the light-receiving surface, a transparent cover adhered onto the electrode and the light receiving surface, and an interconnector at the bottom of this cover; numerous throughholes at the parts from the element-contact part to the externally exposed edge. This prevented the flow out of the adhesive. 3 figs.

  9. Oxidative stress and DNA damage induced by cadmium in the human keratinocyte HaCaT cell line: role of glutathione in the resistance to cadmium.

    Science.gov (United States)

    Nzengue, Yves; Steiman, Régine; Garrel, Catherine; Lefèbvre, Emmanuel; Guiraud, Pascale

    2008-01-14

    Cadmium affects the cellular homeostasis and generates damage via complex mechanisms involving interactions with other metals and oxidative stress induction. In this work we used a human keratinocyte cell line (HaCaT) as a model to study the oxidative damage induced by cadmium to cellular macromolecules, its effect on the antioxidant systems and the role of glutathione in cell protection toward cadmium toxicity. The cells were incubated for 24 and 48 h with cadmium (3, 15, 50 and 100 microM). High doses of cadmium were required to induce a cytotoxicity: 100 microM lead to 30% mortality after 24h and 50% after 48 h. The oxidation of lipids and proteins and the DNA damage, respectively, assessed by thiobarbituric acid reactants determination, thiol group measurement and comet assay, were observed for 50-100 microM cadmium. The cytotoxic effects were strongly correlated to the cellular cadmium content. The glutathione peroxidase and the catalase activities were decreased, while the glutathione reductase activity and the glutathione concentration were increased after cadmium treatment. The superoxide dismutases activities were unchanged. A depletion in glutathione prior to cadmium exposure increased the cytotoxic effects and provoked DNA damage. Our results suggested that the hydroxyl radical could be the major compound involved in the oxidative stress generated by cadmium and that glutathione could play a major role in the protection of HaCaT cells from cytotoxicity but mostly from DNA damage induced by cadmium.

  10. Silicon Solar Cell Turns 50

    Energy Technology Data Exchange (ETDEWEB)

    Perlin, J.

    2004-08-01

    This short brochure describes a milestone in solar (or photovoltaic, PV) research-namely, the 50th anniversary of the invention of the first viable silicon solar cell by three researchers at Bell Laboratories.

  11. Silicon heterojunction solar cells

    CERN Document Server

    Fahrner, W R; Neitzert, H C

    2006-01-01

    The world of today must face up to two contradictory energy problems: on the one hand, there is the sharply growing consumer demand in countries such as China and India. On the other hand, natural resources are dwindling. Moreover, many of those countries which still possess substantial gas and oil supplies are politically unstable. As a result, renewable natural energy sources have received great attention. Among these, solar-cell technology is one of the most promising candidates. However, there still remains the problem of the manufacturing costs of such cells. Many attempts have been made

  12. Solar-Cell String Conveyor

    Science.gov (United States)

    Frasch, W.; Ciavola, S.

    1982-01-01

    String-conveyor portion of solar-array assembly line holds silicon solar cells while assembled into strings and tested. Cells are transported collector-side-down, while uniform cell spacing and registration are maintained. Microprocessor on machine controls indexing of cells.

  13. Emerging Solar Technologies: Perovskite Solar Cell

    Indian Academy of Sciences (India)

    High efficiency, flexibility, and cell architecture of the emerging hybrid halide perovskite have caught the attention of researchers and technologists in the field. This article fo- cuses on the emergence, properties, and current research sta- tus of hybrid perovskite solar cells. 1. Introduction. Gradually, primary energy resources ...

  14. Emerging Solar Technologies: Perovskite Solar Cell

    Indian Academy of Sciences (India)

    Organic–inorganic halide perovskite, a newcomerin the solar cell industry has proved its potential forincreasing efficiency rapidly from 3.8% in 2009 to 22.1% in2016. High efficiency, flexibility, and cell architecture of theemerging hybrid halide perovskite have caught the attentionof researchers and technologists in the field.

  15. Improving efficiency (optimization) of CIGS thin film solar cell using ...

    African Journals Online (AJOL)

    Layers of this type of solar cell are: 1-TCO made of ZnO (zinc oxide) 2- CdS layer gate (cadmium sulphate) with impurities of n 3-CIGS absorber layer with the impurity of p, 4- 5 glass substrate molybdenum layer made of soda. Reduced thickness of the absorbent layer makes the back connection to be closer to the discharge ...

  16. TEMPERATUREEFFECT OFELECTRICALPROPERTIES OF CIGS SOLAR CELL

    Directory of Open Access Journals (Sweden)

    A. M. Ferouani

    2015-07-01

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

  17. Cadmium-induced programmed cell death signaling in tomato suspension cells

    NARCIS (Netherlands)

    Yakimova, E.T.; Woltering, E.J.; Kapchina-Toteva, V.M.

    2009-01-01

    Here we present a summary of our study on cadmium-induced cell death signaling in a model system of suspension-cultured tomato cells. Exposure of the cells to CdSO4 induced typical for PCD (cytoplasm shrinkage and nuclear condensation) morphological changes of the dead cells. Ethylene and hydrogen

  18. Solar cell. Taiyo denchi

    Energy Technology Data Exchange (ETDEWEB)

    Nunoi, Toru.

    1989-08-18

    This invention aims to improve the photovoltaic conversion efficiency with less electrode ares of the solar cell. In this invention, the cell consists of plural number of electrodes for collecting the current from tiny sections distributed on the light-receiving surface and a wiring installed at outside of the light-receiving surface for collecting the current from these electrodes. As a result, it becomes unnecessary to equip an electrode to gather the currents from the electrode to collect the currents from the tiny sections; this increases the light projected area, thus improving the characteristics of the soalr cell. In other words, values of voltage and current are improved in comparison with the conventional construction. 4 figs.

  19. Cascade Organic Solar Cells

    KAUST Repository

    Schlenker, Cody W.

    2011-09-27

    We demonstrate planar organic solar cells consisting of a series of complementary donor materials with cascading exciton energies, incorporated in the following structure: glass/indium-tin-oxide/donor cascade/C 60/bathocuproine/Al. Using a tetracene layer grown in a descending energy cascade on 5,6-diphenyl-tetracene and capped with 5,6,11,12-tetraphenyl- tetracene, where the accessibility of the π-system in each material is expected to influence the rate of parasitic carrier leakage and charge recombination at the donor/acceptor interface, we observe an increase in open circuit voltage (Voc) of approximately 40% (corresponding to a change of +200 mV) compared to that of a single tetracene donor. Little change is observed in other parameters such as fill factor and short circuit current density (FF = 0.50 ± 0.02 and Jsc = 2.55 ± 0.23 mA/cm2) compared to those of the control tetracene-C60 solar cells (FF = 0.54 ± 0.02 and Jsc = 2.86 ± 0.23 mA/cm2). We demonstrate that this cascade architecture is effective in reducing losses due to polaron pair recombination at donor-acceptor interfaces, while enhancing spectral coverage, resulting in a substantial increase in the power conversion efficiency for cascade organic photovoltaic cells compared to tetracene and pentacene based devices with a single donor layer. © 2011 American Chemical Society.

  20. Solar cell materials developing technologies

    CERN Document Server

    Conibeer, Gavin J

    2014-01-01

    This book presents a comparison of solar cell materials, including both new materials based on organics, nanostructures and novel inorganics and developments in more traditional photovoltaic materials. It surveys the materials and materials trends in the field including third generation solar cells (multiple energy level cells, thermal approaches and the modification of the solar spectrum) with an eye firmly on low costs, energy efficiency and the use of abundant non-toxic materials.

  1. Dye solar cell research

    CSIR Research Space (South Africa)

    Cummings, F

    2009-11-01

    Full Text Available Cummings Energy and Processes Materials Science and Manufacturing Council for Scientific and Industrial Research P.O. Box 395 Pretoria 0001, South Africa 27 November 2009 CONTENT head2rightBackground head2rightCSIR Dye Solar Cell Research head2... rightCollaborations and Links © CSIR 2007 www.csir.co.za head2rightAcknowledgements BACKGROUND head2rightSA is dry: Annual rainfall average of 450 mm compared with a world average of 860 mm head2rightOn upside, we have some...

  2. Floating emitter solar cell

    Science.gov (United States)

    Chih, Sah (Inventor); Cheng, Li-Jen (Inventor)

    1987-01-01

    A front surface contact floating emitter solar cell transistor is provided in a semiconductor body (n-type), in which floating emitter sections (p-type) are diffused or implanted in the front surface. Between the emitter sections, a further section is diffused or implanted in the front surface, but isolated from the floating emitter sections, for use either as a base contact to the n-type semiconductor body, in which case the section is doped n+, or as a collector for the adjacent emitter sections.

  3. Module of solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Katsuaki; Ohira, Takeo

    1988-04-30

    It is proposed to apply transparent plastics film on the surface of solar cell module as the substitute of the transparent tempered glass. However, weather proof film made of polyester or polyvinyliden fluoride has a drawback of weak bonding with the filler made of ethylen-vinyl acetate copolymer. This invention relates to the improvement of the bonding characteristics without decreasing the transparency of the film, by covering the surface of it with Al or other metals, or inorganic material such as silicon dioxide, by applying sputtering or vapour deposition method. In addition, application of silan coupling agent is mentioned as an improving method of the bonding. (2 figs)

  4. Dye Sensitized Solar Cell, DSSC

    Directory of Open Access Journals (Sweden)

    Pongsatorn Amornpitoksuk

    2003-07-01

    Full Text Available A dye sensitized solar cell is a new type of solar cell. The operating system of this solar cell type is similar to plant’s photosynthesis process. The sensitizer is available for absorption light and transfer electrons to nanocrystalline metal oxide semiconductor. The ruthenium(II complexes with polypyridyl ligands are usually used as the sensitizers in solar cell. At the present time, the complex of [Ru(2,2',2'’-(COOH3- terpy(NCS3] is the most efficient sensitizer. The total photon to current conversion efficiency was approximately 10% at AM = 1.5.

  5. Space Solar Cell Characterization Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Measures, characterizes, and analyzes photovoltaic materials and devices. The primary focus is the measurement and characterization of solar cell response...

  6. Quantum Junction Solar Cells

    KAUST Repository

    Tang, Jiang

    2012-09-12

    Colloidal quantum dot solids combine convenient solution-processing with quantum size effect tuning, offering avenues to high-efficiency multijunction cells based on a single materials synthesis and processing platform. The highest-performing colloidal quantum dot rectifying devices reported to date have relied on a junction between a quantum-tuned absorber and a bulk material (e.g., TiO 2); however, quantum tuning of the absorber then requires complete redesign of the bulk acceptor, compromising the benefits of facile quantum tuning. Here we report rectifying junctions constructed entirely using inherently band-aligned quantum-tuned materials. Realizing these quantum junction diodes relied upon the creation of an n-type quantum dot solid having a clean bandgap. We combine stable, chemically compatible, high-performance n-type and p-type materials to create the first quantum junction solar cells. We present a family of photovoltaic devices having widely tuned bandgaps of 0.6-1.6 eV that excel where conventional quantum-to-bulk devices fail to perform. Devices having optimal single-junction bandgaps exhibit certified AM1.5 solar power conversion efficiencies of 5.4%. Control over doping in quantum solids, and the successful integration of these materials to form stable quantum junctions, offers a powerful new degree of freedom to colloidal quantum dot optoelectronics. © 2012 American Chemical Society.

  7. Curcumin regulates airway epithelial cell cytokine responses to the pollutant cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Rennolds, Jessica; Malireddy, Smitha; Hassan, Fatemat; Tridandapani, Susheela; Parinandi, Narasimham [Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, The Ohio State University, Columbus, OH 43210 (United States); Boyaka, Prosper N. [Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210 (United States); Cormet-Boyaka, Estelle, E-mail: Estelle.boyaka@osumc.edu [Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, The Ohio State University, Columbus, OH 43210 (United States)

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer Cadmium induces secretion of IL-6 and IL-8 by two distinct pathways. Black-Right-Pointing-Pointer Cadmium increases NAPDH oxidase activity leading to Erk activation and IL-8 secretion. Black-Right-Pointing-Pointer Curcumin prevents cadmium-induced secretion of both IL-6 and IL-8 by airway cells. Black-Right-Pointing-Pointer Curcumin could be use to suppress lung inflammation due to cadmium inhalation. -- Abstract: Cadmium is a toxic metal present in the environment and its inhalation can lead to pulmonary disease such as lung cancer and chronic obstructive pulmonary disease. These lung diseases are characterized by chronic inflammation. Here we show that exposure of human airway epithelial cells to cadmium promotes a polarized apical secretion of IL-6 and IL-8, two pivotal pro-inflammatory cytokines known to play an important role in pulmonary inflammation. We also determined that two distinct pathways controlled secretion of these proinflammatory cytokines by human airway epithelial cells as cadmium-induced IL-6 secretion occurs via an NF-{kappa}B dependent pathway, whereas IL-8 secretion involves the Erk1/2 signaling pathway. Interestingly, the natural antioxidant curcumin could prevent both cadmium-induced IL-6 and IL-8 secretion by human airway epithelial cells. In conclusion, curcumin could be used to prevent airway inflammation due to cadmium inhalation.

  8. Nickel-cadmium battery cell reversal from resistive network effects

    Science.gov (United States)

    Zimmerman, A. H.

    1985-07-01

    During the individual cell short-down procedures often used for storing or reconditioning nickel-cadmium (Ni-Cd) batteries, it is possible for significant reversal of the lowest capacity cells to occur. The reversal is caused by the finite resistance of the common current-carrying leads in the resistive network that is generally used during short-down. A model is developed to evaluate the extent of such a reversal in any specific battery, and the model is verified by means of data from the short-down of a f-cell, 3.5-Ah battery. Computer simulations of short-down on a variety of battery configurations indicate the desirability of controlling capacity imbalances arising from cell configuration and battery management, limiting variability in the short-down resistors, minimizing lead resistances, and optimizing lead configurations.

  9. Carbon nanotube solar cells.

    Directory of Open Access Journals (Sweden)

    Colin Klinger

    Full Text Available We present proof-of-concept all-carbon solar cells. They are made of a photoactive side of predominantly semiconducting nanotubes for photoconversion and a counter electrode made of a natural mixture of carbon nanotubes or graphite, connected by a liquid electrolyte through a redox reaction. The cells do not require rare source materials such as In or Pt, nor high-grade semiconductor processing equipment, do not rely on dye for photoconversion and therefore do not bleach, and are easy to fabricate using a spray-paint technique. We observe that cells with a lower concentration of carbon nanotubes on the active semiconducting electrode perform better than cells with a higher concentration of nanotubes. This effect is contrary to the expectation that a larger number of nanotubes would lead to more photoconversion and therefore more power generation. We attribute this to the presence of metallic nanotubes that provide a short for photo-excited electrons, bypassing the load. We demonstrate optimization strategies that improve cell efficiency by orders of magnitude. Once it is possible to make semiconducting-only carbon nanotube films, that may provide the greatest efficiency improvement.

  10. Analysis of aerospace nickel-cadmium battery cells. [cadmium migration as seen by scanning electron microscopy and metallographic analysis

    Science.gov (United States)

    Eliason, R. R.

    1977-01-01

    Various steps followed in analyzing the electrolyte, separator, and electrodes are reviewed. Specific emphasis is given to scanning electron microscopic and metallographic analysis of the plates. Cadmium migration is defined, its effects and causes are examined, and methods for its reduction in cells are suggested.

  11. Cadmium suppresses the proliferation of piglet Sertoli cells and causes their DNA damage, cell apoptosis and aberrant ultrastructure

    Directory of Open Access Journals (Sweden)

    Zhang Ming

    2010-08-01

    Full Text Available Abstract Objective Very little information is known about the toxic effects of cadmium on somatic cells in mammalian testis. The objective of this study is to explore the toxicity of cadmium on piglet Sertoli cells. Methods Sertoli cells were isolated from piglet testes using a two-step enzyme digestion and followed by differential plating. Piglet Sertoli cells were identified by oil red O staining and Fas ligand (FasL expression as assayed by immunocytochemistry and expression of transferrin and androgen binding protein by RT-PCR. Sertoli cells were cultured in DMEM/F12 supplemented with 10% fetal calf serum in the absence or presence of various concentrations of cadmium chloride, or treatment with p38 MAPK inhibitor SB202190 and with cadmium chloride exposure. Apoptotic cells in seminiferous tubules of piglets were also performed using TUNEL assay in vivo. Results Cadmium chloride inhibited the proliferation of Piglet Sertoli cells as shown by MTT assay, and it increased malondialdehyde (MDA but reduced superoxide dismutase (SOD and Glutathione peroxidase (GSH-Px activity. Inhibitor SB202190 alleviated the proliferation inhibition of cadmium on piglet Sertoli cells. Comet assay revealed that cadmium chloride caused DNA damage of Piglet Sertoli cells and resulted in cell apoptosis as assayed by flow cytometry. The in vivo study confirmed that cadmium induced cell apoptosis in seminiferous tubules of piglets. Transmission electronic microscopy showed abnormal and apoptotic ultrastructure in Piglet Sertoli cells treated with cadmium chloride compared to the control. Conclusion cadmium has obvious adverse effects on the proliferation of piglet Sertoli cells and causes their DNA damage, cell apoptosis, and aberrant morphology. This study thus offers novel insights into the toxicology of cadmium on male reproduction.

  12. Cadmium suppresses the proliferation of piglet Sertoli cells and causes their DNA damage, cell apoptosis and aberrant ultrastructure

    Science.gov (United States)

    2010-01-01

    Objective Very little information is known about the toxic effects of cadmium on somatic cells in mammalian testis. The objective of this study is to explore the toxicity of cadmium on piglet Sertoli cells. Methods Sertoli cells were isolated from piglet testes using a two-step enzyme digestion and followed by differential plating. Piglet Sertoli cells were identified by oil red O staining and Fas ligand (FasL) expression as assayed by immunocytochemistry and expression of transferrin and androgen binding protein by RT-PCR. Sertoli cells were cultured in DMEM/F12 supplemented with 10% fetal calf serum in the absence or presence of various concentrations of cadmium chloride, or treatment with p38 MAPK inhibitor SB202190 and with cadmium chloride exposure. Apoptotic cells in seminiferous tubules of piglets were also performed using TUNEL assay in vivo. Results Cadmium chloride inhibited the proliferation of Piglet Sertoli cells as shown by MTT assay, and it increased malondialdehyde (MDA) but reduced superoxide dismutase (SOD) and Glutathione peroxidase (GSH-Px) activity. Inhibitor SB202190 alleviated the proliferation inhibition of cadmium on piglet Sertoli cells. Comet assay revealed that cadmium chloride caused DNA damage of Piglet Sertoli cells and resulted in cell apoptosis as assayed by flow cytometry. The in vivo study confirmed that cadmium induced cell apoptosis in seminiferous tubules of piglets. Transmission electronic microscopy showed abnormal and apoptotic ultrastructure in Piglet Sertoli cells treated with cadmium chloride compared to the control. Conclusion cadmium has obvious adverse effects on the proliferation of piglet Sertoli cells and causes their DNA damage, cell apoptosis, and aberrant morphology. This study thus offers novel insights into the toxicology of cadmium on male reproduction. PMID:20712887

  13. Thin-film solar cell

    NARCIS (Netherlands)

    Metselaar, J.W.; Kuznetsov, V.I.

    1998-01-01

    The invention relates to a thin-film solar cell provided with at least one p-i-n junction comprising at least one p-i junction which is at an angle alpha with that surface of the thin-film solar cell which collects light during operation and at least one i-n junction which is at an angle beta with

  14. An Introduction to Solar Cells

    Science.gov (United States)

    Feldman, Bernard J.

    2010-01-01

    Most likely, solar cells will play a significant role in this country's strategy to address the two interrelated issues of global warming and dependence on imported oil. The purpose of this paper is to present an explanation of how solar cells work at an introductory high school, college, or university physics course level. The treatment presented…

  15. Analysis of the reflective multibandgap solar cell concept

    Science.gov (United States)

    Stern, T. G.

    1983-01-01

    A new and unique approach to improving photovoltaic conversion efficiency, the reflective multiband gap solar cell concept, was examined. This concept uses back surface reflectors and light trapping with several physically separated cells of different bandgaps to make more effective use of energy from different portions of the solar spectrum. Preliminary tests performed under General Dynamics Independent Research and Development (IRAD) funding have demonstrated the capability for achieving in excess of 20% conversion efficiency with aluminum gallium arsenide and silicon. This study analyzed the ultimate potential for high conversion efficiency with 2, 3, 4, and 5 different bandgap materials, determined the appropriate bandgaps needed to achieve this optimized efficiency, and identified potential problems or constraints. The analysis indicated that an improvement in efficiency of better than 40% could be attained in this multibandgap approach, compared to a single bandgap converter under the same assumptions. Increased absorption loss on the back surface reflector was found to incur a minimal penalty on efficiency for two and three bandgap systems. Current models for bulk absorption losses in 3-5 materials were found to be inadequate for explaining laboratory observed transmission losses. Recommendations included the continued development of high bandgap back surface reflector cells and basic research on semiconductor absorption mechanisms.

  16. High Performance Perovskite Solar Cells

    Science.gov (United States)

    Tong, Xin; Lin, Feng; Wu, Jiang

    2015-01-01

    Perovskite solar cells fabricated from organometal halide light harvesters have captured significant attention due to their tremendously low device costs as well as unprecedented rapid progress on power conversion efficiency (PCE). A certified PCE of 20.1% was achieved in late 2014 following the first study of long‐term stable all‐solid‐state perovskite solar cell with a PCE of 9.7% in 2012, showing their promising potential towards future cost‐effective and high performance solar cells. Here, notable achievements of primary device configuration involving perovskite layer, hole‐transporting materials (HTMs) and electron‐transporting materials (ETMs) are reviewed. Numerous strategies for enhancing photovoltaic parameters of perovskite solar cells, including morphology and crystallization control of perovskite layer, HTMs design and ETMs modifications are discussed in detail. In addition, perovskite solar cells outside of HTMs and ETMs are mentioned as well, providing guidelines for further simplification of device processing and hence cost reduction. PMID:27774402

  17. High Performance Perovskite Solar Cells.

    Science.gov (United States)

    Tong, Xin; Lin, Feng; Wu, Jiang; Wang, Zhiming M

    2016-05-01

    Perovskite solar cells fabricated from organometal halide light harvesters have captured significant attention due to their tremendously low device costs as well as unprecedented rapid progress on power conversion efficiency (PCE). A certified PCE of 20.1% was achieved in late 2014 following the first study of long-term stable all-solid-state perovskite solar cell with a PCE of 9.7% in 2012, showing their promising potential towards future cost-effective and high performance solar cells. Here, notable achievements of primary device configuration involving perovskite layer, hole-transporting materials (HTMs) and electron-transporting materials (ETMs) are reviewed. Numerous strategies for enhancing photovoltaic parameters of perovskite solar cells, including morphology and crystallization control of perovskite layer, HTMs design and ETMs modifications are discussed in detail. In addition, perovskite solar cells outside of HTMs and ETMs are mentioned as well, providing guidelines for further simplification of device processing and hence cost reduction.

  18. Cadmium Chloride Induces DNA Damage and Apoptosis of Human Liver Carcinoma Cells via Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Anthony Skipper

    2016-01-01

    Full Text Available Cadmium is a heavy metal that has been shown to cause its toxicity in humans and animals. Many documented studies have shown that cadmium produces various genotoxic effects such as DNA damage and chromosomal aberrations. Ailments such as bone disease, renal damage, and several forms of cancer are attributed to overexposure to cadmium.  Although there have been numerous studies examining the effects of cadmium in animal models and a few case studies involving communities where cadmium contamination has occurred, its molecular mechanisms of action are not fully elucidated. In this research, we hypothesized that oxidative stress plays a key role in cadmium chloride-induced toxicity, DNA damage, and apoptosis of human liver carcinoma (HepG2 cells. To test our hypothesis, cell viability was determined by MTT assay. Lipid hydroperoxide content stress was estimated by lipid peroxidation assay. Genotoxic damage was tested by the means of alkaline single cell gel electrophoresis (Comet assay. Cell apoptosis was measured by flow cytometry assessment (Annexin-V/PI assay. The result of MTT assay indicated that cadmium chloride induces toxicity to HepG2 cells in a concentration-dependent manner, showing a 48 hr-LD50 of 3.6 µg/mL. Data generated from lipid peroxidation assay resulted in a significant (p < 0.05 increase of hydroperoxide production, specifically at the highest concentration tested. Data obtained from the Comet assay indicated that cadmium chloride causes DNA damage in HepG2 cells in a concentration-dependent manner. A strong concentration-response relationship (p < 0.05 was recorded between annexin V positive cells and cadmium chloride exposure. In summary, these in vitro studies provide clear evidence that cadmium chloride induces oxidative stress, DNA damage, and programmed cell death in human liver carcinoma (HepG2 cells.

  19. Vaccinium corymbosum L. (blueberry) extracts exhibit protective action against cadmium toxicity in Saccharomyces cerevisiae cells.

    Science.gov (United States)

    Oprea, Eliza; Ruta, Lavinia L; Nicolau, Ioana; Popa, Claudia V; Neagoe, Aurora D; Farcasanu, Ileana C

    2014-01-01

    Blueberries (Vaccinium corymbosum L.) are a rich source of antioxidants and their consumption is believed to contribute to food-related protection against oxidative stress. In the present study, the chemoprotective action of blueberry extracts against cadmium toxicity was investigated using a cadmium-hypersensitive strain of Saccharomyces cerevisiae. Four varieties of blueberries were used in the study, and it was found that the extracts with high content of total anthocyanidins exhibited significant protective effect against the toxicity of cadmium and H2O2. Both the blueberry extracts and pure cyanidin exhibited protective effects against cadmium in a dose-dependent manner, but without significantly interfering with the cadmium accumulation by the yeast cells. The results imply that the blueberry extracts might be a potentially valuable food supplement for individuals exposed to high cadmium. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Upconversion in solar cells

    Science.gov (United States)

    2013-01-01

    The possibility to tune chemical and physical properties in nanosized materials has a strong impact on a variety of technologies, including photovoltaics. One of the prominent research areas of nanomaterials for photovoltaics involves spectral conversion. Modification of the spectrum requires down- and/or upconversion or downshifting of the spectrum, meaning that the energy of photons is modified to either lower (down) or higher (up) energy. Nanostructures such as quantum dots, luminescent dye molecules, and lanthanide-doped glasses are capable of absorbing photons at a certain wavelength and emitting photons at a different (shorter or longer) wavelength. We will discuss upconversion by lanthanide compounds in various host materials and will further demonstrate upconversion to work for thin-film silicon solar cells. PMID:23413889

  1. Germanium Nanocrystal Solar Cells

    Science.gov (United States)

    Holman, Zachary Charles

    Greenhouse gas concentrations in the atmosphere are approaching historically unprecedented levels from burning fossil fuels to meet the ever-increasing world energy demand. A rapid transition to clean energy sources is necessary to avoid the potentially catastrophic consequences of global warming. The sun provides more than enough energy to power the world, and solar cells that convert sunlight to electricity are commercially available. However, the high cost and low efficiency of current solar cells prevent their widespread implementation, and grid parity is not anticipated to be reached for at least 15 years without breakthrough technologies. Semiconductor nanocrystals (NCs) show promise for cheap multi-junction photovoltaic devices. To compete with photovoltaic materials that are currently commercially available, NCs need to be inexpensively cast into dense thin films with bulk-like electrical mobilities and absorption spectra that can be tuned by altering the NC size. The Group II-VI and IV-VI NC communities have had some success in achieving this goal by drying and then chemically treating colloidal particles, but the more abundant and less toxic Group IV NCs have proven more challenging. This thesis reports thin films of plasma-synthesized Ge NCs deposited using three different techniques, and preliminary solar cells based on these films. Germanium tetrachloride is dissociated in the presence of hydrogen in a nonthermal plasma to nucleate Ge NCs. Transmission electron microscopy and X-ray diffraction indicate that the particles are nearly monodisperse (standard deviations of 10-15% the mean particle diameter) and the mean diameter can be tuned from 4-15 nm by changing the residence time of the Ge NCs in the plasma. In the first deposition scheme, a Ge NC colloid is formed by reacting nanocrystalline powder with 1-dodecene and dispersing the functionalized NCs in a solvent. Films are then formed on substrates by drop-casting the colloid and allowing it to dry

  2. Performace of Dilute Nitride Triple Junction Space Solar Cell Grown by MBE

    Directory of Open Access Journals (Sweden)

    Aho Arto

    2017-01-01

    Full Text Available Dilute nitride arsenide antimonide compounds offer widely tailorable band-gaps, ranging from 0.8 eV to 1.4 eV, for the development of lattice-matched multijunction solar cells with three or more junctions. Here we report on the performance of GaInP/GaAs/GaInNAsSb solar cell grown by molecular beam epitaxy. An efficiency of 27% under AM0 conditions is demonstrated. In addition, the cell was measured at different temperatures. The short circuit current density exhibited a temperature coefficient of 0.006 mA/cm2/°C while the corresponding slope for the open circuit voltage was −6.8 mV/°C. Further efficiency improvement, up to 32%, is projected by better current balancing and structural optimization.

  3. Nanostructuring of Solar Cell Surfaces

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Schmidt, Michael Stenbæk

    Solar energy is by far the most abundant renewable energy source available, but the levelized cost of solar energy is still not competitive with that of fossil fuels. Therefore there is a need to improve the power conversion effciency of solar cells without adding to the production cost. The main...... objective of this PhD thesis is to develop nanostructured silicon (Si) solar cells with higher power conversion efficiency using only scalable and cost-efficient production methods. The nanostructures, known as 'black silicon', are fabricated by single-step, maskless reactive ion etching and used as front....... This result indicates the potential of improved cell performance and higher output power at diffuse light conditions and during daily and yearly operation. A second batch of RIEtextured solar cells with laser-doped selective emitters (LDSE) was fabricated. A power conversion eciency of 18.1% and a ll factor...

  4. Photon management in solar cells

    CERN Document Server

    Rau, Uwe; Gombert, Andreas

    2015-01-01

    Written by renowned experts in the field of photon management in solar cells, this one-stop reference gives an introduction to the physics of light management in solar cells, and discusses the different concepts and methods of applying photon management. The authors cover the physics, principles, concepts, technologies, and methods used, explaining how to increase the efficiency of solar cells by splitting or modifying the solar spectrum before they absorb the sunlight. In so doing, they present novel concepts and materials allowing for the cheaper, more flexible manufacture of solar cells and systems. For educational purposes, the authors have split the reasons for photon management into spatial and spectral light management. Bridging the gap between the photonics and the photovoltaics communities, this is an invaluable reference for materials scientists, physicists in industry, experimental physicists, lecturers in physics, Ph.D. students in physics and material sciences, engineers in power technology, appl...

  5. Effect of Acute Toxicity of Cadmium in Mice Kidney Cells

    Directory of Open Access Journals (Sweden)

    Masoomeh Masoomi Karimi

    2012-11-01

    Full Text Available Background: Cadmium is one of the most toxic heavy metals in our environment having a very strong ability to accumulate in body organs, especially in kidney. The present study was done to determine the genotoxicity and cytotoxicity in kidneys of rats exposed to cadmium. Methods: Male rats (n=30, kept in standard conditions were used in this study. The animals were randomly divided into 2 groups (control and treatment. The treatment group was intraperitoneally injected with Cd (300µm/kg at hours 0, 6, 12, 24, 48. Twenty four hours after the last injection, the rats were sacrificed and their kidneys were obtained. Then oxidative stress markers, malondialdehide (MDA, glutathione (GSH, and superoxide dismutase (SOD, were assayed in homogenized kidney for studying their cytotoxicity. For genotoxicity and DNA damage studies, Comet assay was run on isolated kidney cells. Data analysis was done by t-test and ANOVA using SPSS software version 15. Results: MDA and GSH concentrations in normal and Cd exposed kidney cells were 287.01±37.30nmol/g.pr and 15.61±3.89µmol/g.pr and 609.24±87.87nmol/g.pr and 28.52±5.22µmol/g.pr, respectively. In addition, SOD activity in normal and Cd exposed kidney cells were 77.75±4.12 and 218.91±5.40 U/mg.pr, respectively. Comet assay results (content comet length, tail length, and head diameter showed DNA breakage in the treatment group that was stimulated by Cd which was not seen in the control group. Conclusion: The results demonstrated the genotoxicity effect of Cd on kidney cells as well as the ability of Cd to producing cytotoxicity.

  6. Design and characterization of a dual-band perfect metamaterial absorber for solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Rufangura, Patrick [Sustainable Environment and Energy Systems, Middle East Technical University - Northern Cyprus Campus, Kalkanli, Guzelyurt, 99738, TRNC/Mersin 10 (Turkey); Sabah, Cumali, E-mail: sabah@metu.edu.tr [Department of Electrical and Electronics Engineering, Middle East Technical University - Northern Cyprus Campus, Kalkanli, Guzelyurt, 99738, TRNC/Mersin 10 (Turkey)

    2016-06-25

    This paper proposes a metamaterial absorber design for solar energy harvesting using a simplified and symmetric structure. A unit cell of this design consists of three important layers namely, the bottom metallic layer, which is gold lossy, the intermediate layer: made of a lossy dielectric material that is gallium arsenide and patches which formed by a combination of gold and gallium arsenide. These three important layers are being carefully arranged at the top of a dielectric spacer. The geometric structure was being examined for its contribution towards absorption characteristics. The simulation results show outstanding dual-bands absorption (99.96% and 99.37%) in the visible frequency regime of electromagnetic wave. Due to the excellent symmetric nature of the proposed structure, its absorptance capacity exhibits polarization insensitivity for a wide range of incident angles for electromagnetic radiation. - Highlights: • New and dual-band metamaterial absorber for solar cells. • Geometrically simple and easy to fabricate metamaterial absorber. • Wide range of visible range scavenging applications. • Efficient harvesting for the novel photonic materials and innovative photonic devices.

  7. Module level solutions to solar cell polarization

    Science.gov (United States)

    Xavier, Grace , Li; Bo, [San Jose, CA

    2012-05-29

    A solar cell module includes interconnected solar cells, a transparent cover over the front sides of the solar cells, and a backsheet on the backsides of the solar cells. The solar cell module includes an electrical insulator between the transparent cover and the front sides of the solar cells. An encapsulant protectively packages the solar cells. To prevent polarization, the insulator has resistance suitable to prevent charge from leaking from the front sides of the solar cells to other portions of the solar cell module by way of the transparent cover. The insulator may be attached (e.g., by coating) directly on an underside of the transparent cover or be a separate layer formed between layers of the encapsulant. The solar cells may be back junction solar cells.

  8. Buffer layer between a planar optical concentrator and a solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Solano, Manuel E. [Departamento de Ingeniería Matemática and CI" 2 MA, Universidad de Concepción, Concepción, Casilla 160-C (Chile); Barber, Greg D. [Penn State Institute of Energy and the Environment, Pennsylvania State University, University Park, PA 16802 (United States); Department of Chemistry, Pennsylvania State University, University Park, PA 16802 (United States); Lakhtakia, Akhlesh [Department of Engineering Science and Mechanics, Pennsylvania State University, University Park, PA 16802 (United States); Faryad, Muhammad [Department of Physics, Lahore University of Management Sciences, Lahore 54792 (Pakistan); Monk, Peter B. [Department of Mathematical Sciences, University of Delaware, Newark, DE 19716 (United States); Mallouk, Thomas E. [Department of Chemistry, Pennsylvania State University, University Park, PA 16802 (United States)

    2015-09-15

    The effect of inserting a buffer layer between a periodically multilayered isotropic dielectric (PMLID) material acting as a planar optical concentrator and a photovoltaic solar cell was theoretically investigated. The substitution of the photovoltaic material by a cheaper dielectric material in a large area of the structure could reduce the fabrication costs without significantly reducing the efficiency of the solar cell. Both crystalline silicon (c-Si) and gallium arsenide (GaAs) were considered as the photovoltaic material. We found that the buffer layer can act as an antireflection coating at the interface of the PMLID and the photovoltaic materials, and the structure increases the spectrally averaged electron-hole pair density by 36% for c-Si and 38% for GaAs compared to the structure without buffer layer. Numerical evidence indicates that the optimal structure is robust with respect to small changes in the grating profile.

  9. Phase equilibrium modeling for high temperature metallization on GaAs solar cells

    Science.gov (United States)

    Chung, M. A.; Davison, J. E.; Smith, S. R.

    1991-01-01

    Recent trends in performance specifications and functional requirements have brought about the need for high temperature metallization technology to be developed for survivable DOD space systems and to enhance solar cell reliability. The temperature constitution phase diagrams of selected binary and ternary systems were reviewed to determine the temperature and type of phase transformation present in the alloy systems. Of paramount interest are the liquid-solid and solid-solid transformations. Data are being utilized to aid in the selection of electrical contact materials to gallium arsenide solar cells. Published data on the phase diagrams for binary systems is readily available. However, information for ternary systems is limited. A computer model is being developed which will enable the phase equilibrium predictions for ternary systems where experimental data is lacking.

  10. Effects of growth temperature and device structure on GaP solar cells grown by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Vaisman, M.; Tomasulo, S.; Masuda, T.; Lang, J. R.; Faucher, J.; Lee, M. L. [Department of Electrical Engineering, Yale University, New Haven, Connecticut 06511 (United States)

    2015-02-09

    Gallium phosphide (GaP) is an attractive candidate for wide-bandgap solar cell applications, possessing the largest bandgap of the III-arsenide/phosphides without aluminum. However, GaP cells to date have exhibited poor internal quantum efficiency (IQE), even for photons absorbed by direct transitions, motivating improvements in material quality and device structure. In this work, we investigated GaP solar cells grown by molecular beam epitaxy over a range of substrate temperatures, employing a much thinner emitter than in prior work. Higher growth temperatures yielded the best solar cell characteristics, indicative of increased diffusion lengths. Furthermore, the inclusion of an AlGaP window layer improved both open-circuit voltage and short wavelength IQE.

  11. Sensitivity to cadmium-induced genotoxicity in rat testicular cells is associated with minimal expression of the metallothionein gene.

    Science.gov (United States)

    Shiraishi, N; Hochadel, J F; Coogan, T P; Koropatnick, J; Waalkes, M P

    1995-02-01

    Cadmium is a carcinogenic metal. Although the mechanism of tumor induction is unknown, DNA/metal interactions may be involved. Metallothionein can protect against cadmium toxicity in our previous work it was shown to reduce cadmium genotoxicity in cultured cells. To extend these results, the genotoxicity of cadmium was studied in R2C cells, a rat testicular Leydig cell line. The R2C cells were very sensitive to cadmium-induced single-strand DNA damage (SSD), as measured by alkaline elution. SSD occurred in R2C cells after treatment with 25 and 50 microM CdCl2 for 2 hr. Prior work showed other cells required much higher levels of cadmium (approximately 500 microM) to induce genotoxicity. The genotoxic levels of cadmium (25-50 microM) were not cytotoxic in R2C cells as assessed by a metabolic activity (MTT) assay. Pretreatment of R2C cells with a low cadmium dose (2 microM, 24 hr) had no effect on cadmium-induced SSD, in contrast to prior work in other cells where such pretreatments reduced SSD through metallothionein gene activation. In fact, cadmium or zinc treatments resulted in little or no increase in metallothionein gene expression in R2C cells as determined by Northern blot analysis for metallothionein mRNA using cDNA or oligonucleotide probes and radioimmunoassay for metallothionein protein production. Basal metallothionein mRNA was essentially nondetectable. Induction of a cadmium-binding protein in R2C cells did occur, as determined by Cd-heme assay, but did not induce tolerance to SSD. In vivo, the Leydig cell is a target for cadmium carcinogenicity and its cadmium-binding protein is thought not to be a true metallothionein. These results indicate that R2C cells are sensitive to cadmium-induced genotoxicity and that this sensitivity is associated with minimal expression of the metallothionein gene.

  12. A Biphasic Ligand Exchange Reaction on Cdse Nanoparticles: Introducing Undergraduates to Functionalizing Nanoparticles for Solar Cells

    Science.gov (United States)

    Zemke, Jennifer M.; Franz, Justin

    2016-01-01

    Semiconductor nanoparticles, including cadmium selenide (CdSe) particles, are attractive as light harvesting materials for solar cells. In the undergraduate laboratory, the size-tunable optical and electronic properties can be easily investigated; however, these nanoparticles (NPs) offer another platform for application-based tunability--the NP…

  13. Dust Removal from Solar Cells

    Science.gov (United States)

    Ashpis, David E. (Inventor)

    2015-01-01

    A solar panel cleaning device includes a solar panel having a plurality of photovoltaic cells arranged in rows and embedded in the solar panel with space between the rows. A transparent dielectric overlay is affixed to the solar panel. A plurality of electrode pairs each of which includes an upper and a lower electrode are arranged on opposite sides of the transparent dielectric and are affixed thereto. The electrodes may be transparent electrodes which may be arranged without concern for blocking sunlight to the solar panel. The solar panel may be a dielectric and its dielectric properties may be continuously and spatially variable. Alternatively the dielectric used may have dielectric segments which produce different electrical field and which affects the wind "generated."

  14. A simple model of space radiation damage in GaAs solar cells

    Science.gov (United States)

    Wilson, J. W.; Stith, J. J.; Stock, L. V.

    1983-01-01

    A simple model is derived for the radiation damage of shallow junction gallium arsenide (GaAs) solar cells. Reasonable agreement is found between the model and specific experimental studies of radiation effects with electron and proton beams. In particular, the extreme sensitivity of the cell to protons stopping near the cell junction is predicted by the model. The equivalent fluence concept is of questionable validity for monoenergetic proton beams. Angular factors are quite important in establishing the cell sensitivity to incident particle types and energies. A fluence of isotropic incidence 1 MeV electrons (assuming infinite backing) is equivalent to four times the fluence of normal incidence 1 MeV electrons. Spectral factors common to the space radiations are considered, and cover glass thickness required to minimize the initial damage for a typical cell configuration is calculated. Rough equivalence between the geosynchronous environment and an equivalent 1 MeV electron fluence (normal incidence) is established.

  15. Fundamentals of thin solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Yablonovitch, E. [Univ. of California, Los Angeles, CA (United States)

    1995-08-01

    It is now widely recognized that thin solar cells can present certain advantages for performance and cost. This is particularly the case when light trapping in the semiconductor film is incorporated, as compensation for the diminished single path thickness of the solar cell. In a solar cell thinner than a minority carrier diffusion length, the current collection is of course very easy. More importantly the concentration of an equivalent number of carriers in a thinner volume results in a higher Free Energy, or open circuit voltage. This extra Free Energy may be regarded as due to the concentration factor, just as it would be for photons, electrons, or for any chemical species. The final advantage of a thin solar cell is in the diminished material usage, a factor of considerable importance when we consider the material cost of the high quality semiconductors which we hope to employ.

  16. Solar cell with back side contacts

    Science.gov (United States)

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

    2013-12-24

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

  17. Nanostructures for Organic Solar Cells

    DEFF Research Database (Denmark)

    Goszczak, Arkadiusz Jarosław

    2016-01-01

    The experimental work in this thesis is focused on the fabrication of nanostructures that can be implemented in organic solar cell (OSC) architecture for enhancement of the device performance. Solar devices made from organic material are gaining increased attention, compared to their inorganic...... technique. Resist imprinted Al dimples drag the main focus showing increase in absorption and efficiency enhancement in poly(3-hexylthiophene-2,5-diyl) (P3HT) and Phenyl-C61-butyric acid methyl (PCBM) BHJ devices. Not limited to this, nanostructures by imprinting the organic layer of P3HT:PCBM and imprinted...... for organic solar cell applications, opening new patterning possibilities....

  18. High-efficiency "green" quantum dot solar cells.

    Science.gov (United States)

    Pan, Zhenxiao; Mora-Seró, Iván; Shen, Qing; Zhang, Hua; Li, Yan; Zhao, Ke; Wang, Jin; Zhong, Xinhua; Bisquert, Juan

    2014-06-25

    Semiconductor quantum dots (QDs) are extremely interesting materials for the development of photovoltaic devices, but currently the present the drawback is that the most efficient devices have been prepared with toxic heavy metals of Cd or Pb. Solar cells based on "green" QDs--totally free of Cd or Pb--present a modest efficiency of 2.52%. Herein we achieve effective surface passivation of the ternary CuInS2 (CIS) QDs that provides high photovoltaic quality core/shell CIS/ZnS (CIS-Z) QDs, leading to the development of high-efficiency green QD solar cells that surpass the performance of those based on the toxic cadmium and lead chalcogenides QDs. Using wide absorption range QDs, CIS-Z-based quantum dot sensitized solar cell (QDSC) configuration with high QD loading and with the benefit of the recombination reduction with type-I core/shell structure, we boost the power conversion efficiency of Cd- and Pb-free QDSC to a record of 7.04% (with certified efficiency of 6.66%) under AM 1.5G one sun irradiation. This efficiency is the best performance to date for QDSCs and also demonstrates that it is possible to obtain comparable or even better photovoltaic performance from green CIS QDs to the toxic cadmium and lead chalcogenides QDs.

  19. Industrial Silicon Wafer Solar Cells

    Directory of Open Access Journals (Sweden)

    Dirk-Holger Neuhaus

    2007-01-01

    Full Text Available In 2006, around 86% of all wafer-based silicon solar cells were produced using screen printing to form the silver front and aluminium rear contacts and chemical vapour deposition to grow silicon nitride as the antireflection coating onto the front surface. This paper reviews this dominant solar cell technology looking into state-of-the-art equipment and corresponding processes for each process step. The main efficiency losses of this type of solar cell are analyzed to demonstrate the future efficiency potential of this technology. In research and development, more various advanced solar cell concepts have demonstrated higher efficiencies. The question which arises is “why are new solar cell concepts not transferred into industrial production more frequently?”. We look into the requirements a new solar cell technology has to fulfill to have an advantage over the current approach. Finally, we give an overview of high-efficiency concepts which have already been transferred into industrial production.

  20. Solar electron source and thermionic solar cell

    Directory of Open Access Journals (Sweden)

    Parham Yaghoobi

    2012-12-01

    Full Text Available Common solar technologies are either photovoltaic/thermophotovoltaic, or use indirect methods of electricity generation such as boiling water for a steam turbine. Thermionic energy conversion based on the emission of electrons from a hot cathode into vacuum and their collection by an anode is also a promising route. However, thermionic solar conversion is extremely challenging as the sunlight intensity is too low for heating a conventional cathode to thermionic emission temperatures in a practical manner. Therefore, compared to other technologies, little has been done in this area, and the devices have been mainly limited to large experimental apparatus investigated for space power applications. Based on a recently observed “Heat Trap” effect in carbon nanotube arrays, allowing their efficient heating with low-power light, we report the first compact thermionic solar cell. Even using a simple off-the-shelf focusing lens, the device delivered over 1 V across a load. The device also shows intrinsic storage capacity.

  1. DNA Damage of Lung Cells from Immature Cadmium-Ingested Mice

    Directory of Open Access Journals (Sweden)

    Xue-feng Yang

    2014-01-01

    Full Text Available The objective of this study was to investigate the effects of cadmium on DNA damage of lung cells in immature animals. Seventy-two immature mice were randomly divided into twelve cadmium-ingested groups including low dose (1/100 LD50, 1.87 mg/kg BW, middle dose (1/50 LD50, 3.74 mg/kg BW, high dose (1/25 LD50, 7.48 mg/kg BW and control group, and exposed to cadmium chloride for 10, 20 and 30 days, respectively. Mice were sacrificed after cadmium exposure for different time, and lung cells were collected to investigate DNA damage by comet assay. The results showed that comet tailing ratio, tail length, comet length, tail moment, Olive tail moment and damaged grade of lung cells from immature mice increased along with increasing of cadmium exposure dose and time. In low dose group treated for 30 days, there was significance (P<0.05 in comet length or high significance (P<0.01 in other parameters compared with control group or low dose group treated for 10 days. When mice were exposed to cadmium at high dose for 30 days, DNA of lung cells was damaged most seriously. Our results indicate that cadmium can induce DNA damage of lung cells from immature mice in dose- dependent and time-dependent manners, and DNA will be damaged when immature mice exposed to cadmium for long time even at low dose. Meanwhile, comet assay can be considered as a powerful and sensitive biomarker assay in risk assessment of immature animals exposed to cadmium.

  2. Cadmium Chloride Induces DNA Damage and Apoptosis of Human Liver Carcinoma Cells via Oxidative Stress

    National Research Council Canada - National Science Library

    Skipper, Anthony; Sims, Jennifer N; Yedjou, Clement G; Tchounwou, Paul B

    2016-01-01

    ... mechanisms of action are not fully elucidated. In this research, we hypothesized that oxidative stress plays a key role in cadmium chloride-induced toxicity, DNA damage, and apoptosis of human liver carcinoma (HepG₂) cells...

  3. NREL preprints for the 23rd IEEE Photovoltaic Specialists Conference

    Energy Technology Data Exchange (ETDEWEB)

    Fitzgerald, M. [ed.

    1993-05-01

    Topics covered include various aspects of solar cell fabrication and performance. Aluminium-gallium arsenides, cadmium telluride, amorphous silicon, and copper-indium-gallium selenides are all characterized in their applicability in solar cells.

  4. High Performance Ultrathin GaAs Solar Cells Enabled with Heterogeneously Integrated Dielectric Periodic Nanostructures.

    Science.gov (United States)

    Lee, Sung-Min; Kwong, Anthony; Jung, Daehwan; Faucher, Joseph; Biswas, Roshni; Shen, Lang; Kang, Dongseok; Lee, Minjoo Larry; Yoon, Jongseung

    2015-10-27

    Due to their favorable materials properties including direct bandgap and high electron mobilities, epitaxially grown III-V compound semiconductors such as gallium arsenide (GaAs) provide unmatched performance over silicon in solar energy harvesting. Nonetheless, their large-scale deployment in terrestrial photovoltaics remains challenging mainly due to the high cost of growing device quality epitaxial materials. In this regard, reducing the thickness of constituent active materials under appropriate light management schemes is a conceptually viable option to lower the cost of GaAs solar cells. Here, we present a type of high efficiency, ultrathin GaAs solar cell that incorporates bifacial photon management enabled by techniques of transfer printing to maximize the absorption and photovoltaic performance without compromising the optimized electronic configuration of planar devices. Nanoimprint lithography and dry etching of titanium dioxide (TiO2) deposited directly on the window layer of GaAs solar cells formed hexagonal arrays of nanoscale posts that serve as lossless photonic nanostructures for antireflection, diffraction, and light trapping in conjunction with a co-integrated rear-surface reflector. Systematic studies on optical and electrical properties and photovoltaic performance in experiments, as well as numerical modeling, quantitatively describe the optimal design rules for ultrathin, nanostructured GaAs solar cells and their integrated modules.

  5. Advances in Perovskite Solar Cells.

    Science.gov (United States)

    Zuo, Chuantian; Bolink, Henk J; Han, Hongwei; Huang, Jinsong; Cahen, David; Ding, Liming

    2016-07-01

    Organolead halide perovskite materials possess a combination of remarkable optoelectronic properties, such as steep optical absorption edge and high absorption coefficients, long charge carrier diffusion lengths and lifetimes. Taken together with the ability for low temperature preparation, also from solution, perovskite-based devices, especially photovoltaic (PV) cells have been studied intensively, with remarkable progress in performance, over the past few years. The combination of high efficiency, low cost and additional (non-PV) applications provides great potential for commercialization. Performance and applications of perovskite solar cells often correlate with their device structures. Many innovative device structures were developed, aiming at large-scale fabrication, reducing fabrication cost, enhancing the power conversion efficiency and thus broadening potential future applications. This review summarizes typical structures of perovskite solar cells and comments on novel device structures. The applications of perovskite solar cells are discussed.

  6. Advances in Perovskite Solar Cells

    Science.gov (United States)

    Zuo, Chuantian; Bolink, Henk J.; Han, Hongwei; Huang, Jinsong

    2016-01-01

    Organolead halide perovskite materials possess a combination of remarkable optoelectronic properties, such as steep optical absorption edge and high absorption coefficients, long charge carrier diffusion lengths and lifetimes. Taken together with the ability for low temperature preparation, also from solution, perovskite‐based devices, especially photovoltaic (PV) cells have been studied intensively, with remarkable progress in performance, over the past few years. The combination of high efficiency, low cost and additional (non‐PV) applications provides great potential for commercialization. Performance and applications of perovskite solar cells often correlate with their device structures. Many innovative device structures were developed, aiming at large‐scale fabrication, reducing fabrication cost, enhancing the power conversion efficiency and thus broadening potential future applications. This review summarizes typical structures of perovskite solar cells and comments on novel device structures. The applications of perovskite solar cells are discussed. PMID:27812475

  7. Effect of the cadmium chloride treatment on RF sputtered Cd{sub 0.6}Zn{sub 0.4}Te films for application in multijunction solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Shimpi, Tushar M., E-mail: mechanical.tushar@gmail.com; Kephart, Jason M.; Swanson, Drew E.; Munshi, Amit H.; Sampath, Walajabad S. [Department of Mechanical Engineering, Colorado State University, 1320 Campus Delivery, Fort Collins, Colorado 80523 (United States); Abbas, A.; Walls, John M. [CREST (Centre for Renewable Energy Systems and Technology), Loughborough University, Loughborough LE11 3TU (United Kingdom)

    2016-09-15

    Single phase Cd{sub 0.6}Zn{sub 0.4}Te (CdZnTe) films of 1 μm thickness were deposited by radio frequency planar magnetron sputter deposition on commercial soda lime glass samples coated with fluorine-doped tin oxide and cadmium sulphide (CdS). The stack was then treated with cadmium chloride (CdCl{sub 2}) at different temperatures using a constant treatment time. The effect of the CdCl{sub 2} treatment was studied using optical, materials, and electrical characterization of the samples and compared with the as-deposited CdZnTe film with the same stack configuration. The band gap deduced from Tauc plots on the as-deposited CdZnTe thin film was 1.72 eV. The deposited film had good crystalline quality with a preferred orientation along the {111} plane. After the CdCl{sub 2} treatment, the absorption edge shifted toward longer wavelength region and new peaks corresponding to cadmium telluride (CdTe) emerged in the x-ray diffraction pattern. This suggested loss of zinc after the CdCl{sub 2} treatment. The cross sectional transmission electron microscope images of the sample treated at 400 °C and the energy dispersive elemental maps revealed the absence of chlorine along the grain boundaries of CdZnTe and residual CdTe. The presence of chlorine in the CdTe devices plays a vital role in drastically improving the device performance which was not observed in CdZnTe samples treated with CdCl{sub 2}. The loss of zinc from the surface and incomplete recrystallization of the grains together with the presence of high densities of stacking faults were observed. The surface images using scanning electron microscopy showed that the morphology of the grains changed from small spherical shape to large grains formed due to the fusion of small grains with distinct grain boundaries visible at the higher CdCl{sub 2} treatment temperatures. The absence of chlorine along the grain boundaries, incomplete recrystallization and distinct grain boundaries is understood to cause the poor

  8. Nature's Solar Cell

    Indian Academy of Sciences (India)

    The sun is the principal source of energy for all life on earth. Yet, only green plants and certain bacteria can directly use solar energy by converting the light energy into chemical energy. They do this by photosynthesis in specialised organelles called chloroplasts. The energy then trickles down to all the other organisms ...

  9. Molecular Mechanisms of Malignant Transformation by Low Dose Cadmium in Normal Human Bronchial Epithelial Cells.

    Directory of Open Access Journals (Sweden)

    Laura Cartularo

    Full Text Available Cadmium is a carcinogenic metal, the mechanisms of which are not fully understood. In this study, human bronchial epithelial cells were transformed with sub-toxic doses of cadmium (0.01, 0.05, and 0.1 μM and transformed clones were characterized for gene expression changes using RNA-seq, as well as other molecular measurements. 440 genes were upregulated and 47 genes were downregulated in cadmium clones relative to control clones over 1.25-fold. Upregulated genes were associated mostly with gene ontology terms related to embryonic development, immune response, and cell movement, while downregulated genes were associated with RNA metabolism and regulation of transcription. Several embryonic genes were upregulated, including the transcription regulator SATB2. SATB2 is critical for normal skeletal development and has roles in gene expression regulation and chromatin remodeling. Small hairpin RNA knockdown of SATB2 significantly inhibited growth in soft agar, indicating its potential as a driver of metal-induced carcinogenesis. An increase in oxidative stress and autophagy was observed in cadmium clones. In addition, the DNA repair protein O6-methylguanine-DNA-methyltransferase was depleted by transformation with cadmium. MGMT loss caused significant decrease in cell viability after treatment with the alkylating agent temozolomide, demonstrating diminished capacity to repair such damage. Results reveal various mechanisms of cadmium-induced malignant transformation in BEAS-2B cells including upregulation of SATB2, downregulation of MGMT, and increased oxidative stress.

  10. Development of concentrator solar cells

    Energy Technology Data Exchange (ETDEWEB)

    1994-08-01

    A limited pilot production run on PESC silicon solar cells for use at high concentrations (200 to 400 suns) is summarized. The front contact design of the cells was modified for operation without prismatic covers. The original objective of the contract was to systematically complete a process consolidation phase, in which all the, process improvements developed during the contract would be combined in a pilot production run. This pilot run was going to provide, a basis for estimating cell costs when produced at high throughput. Because of DOE funding limitations, the Photovoltaic Concentrator Initiative is on hold, and Applied Solar`s contract was operated at a low level of effort for most of 1993. The results obtained from the reduced scope pilot run showed the effects of discontinuous process optimization and characterization. However, the run provided valuable insight into the technical areas that can be optimized to achieve the original goals of the contract.

  11. An experimental investigation of the feasibility of using silicone and gallium arsenide solar batteries on space vehicles for receiving energy of laser infrared emission

    Science.gov (United States)

    Bogushevskaya, V. A.; Zhalnin, B. V.; Zayats, O. V.; Maslyakov, Ya. N.; Matsak, I. S.; Nikonov, A. A.; Obrucheva, Ye. V.; Tugaenko, V. Yu.

    2012-12-01

    The feasibility of transmitting electric power in space to solar batteries of space vehicles via the channel of laser infrared emission is shown. Evaluation of the efficiency of solar batteries for the given type of power transmission has been made. Possible methods of optimizing the design of space solar batteries in regard to conditions of detection of energy of laser infrared emission have been discussed.

  12. Solar cell circuit and method for manufacturing solar cells

    Science.gov (United States)

    Mardesich, Nick (Inventor)

    2010-01-01

    The invention is a novel manufacturing method for making multi-junction solar cell circuits that addresses current problems associated with such circuits by allowing the formation of integral diodes in the cells and allows for a large number of circuits to readily be placed on a single silicon wafer substrate. The standard Ge wafer used as the base for multi-junction solar cells is replaced with a thinner layer of Ge or a II-V semiconductor material on a silicon/silicon dioxide substrate. This allows high-voltage cells with multiple multi-junction circuits to be manufactured on a single wafer, resulting in less array assembly mass and simplified power management.

  13. InGaAsP Solar Cells Grown by Hydride Vapor Phase Epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Nikhil; Simon, John; Schulte, Kevin L.; Dippo, Patricia; Young, Michelle; Young, David L.; Ptak, Aaron J.

    2016-11-21

    Hydride vapor phase epitaxy (HVPE) has recently reemerged as a low-cost, high-throughput alternative to metalorganic chemical vapor deposition (MOCVD) for the growth of high-efficiency III-V solar cells. Quaternary InGaAsP solar cells in the bandgap range of ~1.7-1.8 eV are promising top-cell candidates for integration in Ill-V/Si tandem cells with projected one-sun efficiencies exceeding 30%. In this work, we report on the development of lattice-matched InGaAsP solar cells grown on GaAs substrates via HVPE at very high growth rates of ~0.7 um/min. We demonstrate prototype 1.7 eV InGaAsP solar cells with an open-circuit voltage of 1.11 V. The short-circuit current is limited by the lack of a window layer in these early stage devices. The photo response of 1.7 InGaAsP solar cell with ~1.1 um thick base layer is found to be nearly insensitive to variation in p-type base doping concentration in the range from Na - 4x1016 to - 1x1017 cm-3, indicating an effective carrier collection length on the order of - 1.1 um or higher in our devices. These initial InGaAsP cell results are encouraging and highlight the viability of HVPE to produce mixed arsenide-phosphide solar cells grown lattice-matched on GaAs.

  14. Organic and hybrid solar cells

    CERN Document Server

    Huang, Hui

    2014-01-01

    This book delivers a comprehensive evaluation of organic and hybrid solar cells and identifies their fundamental principles and numerous applications. Great attention is given to the charge transport mechanism, donor and acceptor materials, interfacial materials, alternative electrodes, device engineering and physics, and device stability. The authors provide an industrial perspective on the future of photovoltaic technologies.

  15. Fullerene based organic solar cells

    NARCIS (Netherlands)

    Popescu, Lacramioara Mihaela

    2008-01-01

    The direct conversion of the sunlight into electricity is the most elegant process to generate environmentally-friendly renewable energy. Plastic solar cells offer the prospect of flexible, lightweight, lower cost of manufacturing, and hopefully an efficient way to produce electricity from sunlight.

  16. Graded bandgap perovskite solar cells

    Science.gov (United States)

    Ergen, Onur; Gilbert, S. Matt; Pham, Thang; Turner, Sally J.; Tan, Mark Tian Zhi; Worsley, Marcus A.; Zettl, Alex

    2017-05-01

    Organic-inorganic halide perovskite materials have emerged as attractive alternatives to conventional solar cell building blocks. Their high light absorption coefficients and long diffusion lengths suggest high power conversion efficiencies, and indeed perovskite-based single bandgap and tandem solar cell designs have yielded impressive performances. One approach to further enhance solar spectrum utilization is the graded bandgap, but this has not been previously achieved for perovskites. In this study, we demonstrate graded bandgap perovskite solar cells with steady-state conversion efficiencies averaging 18.4%, with a best of 21.7%, all without reflective coatings. An analysis of the experimental data yields high fill factors of ~75% and high short-circuit current densities up to 42.1 mA cm-2. The cells are based on an architecture of two perovskite layers (CH3NH3SnI3 and CH3NH3PbI3-xBrx), incorporating GaN, monolayer hexagonal boron nitride, and graphene aerogel.

  17. Semi-transparent solar cells

    Science.gov (United States)

    Sun, J.; Jasieniak, J. J.

    2017-03-01

    Semi-transparent solar cells are a type of technology that combines the benefits of visible light transparency and light-to-electricity conversion. One of the biggest opportunities for such technologies is in their integration as windows and skylights within energy-sustainable buildings. Currently, such building integrated photovoltaics (BIPV) are dominated by crystalline silicon based modules; however, the opaque nature of silicon creates a unique opportunity for the adoption of emerging photovoltaic candidates that can be made truly semi-transparent. These include: amorphous silicon-, kesterite-, chalcopyrite-, CdTe-, dye-sensitized-, organic- and perovskite- based systems. For the most part, amorphous silicon has been the workhorse in the semi-transparent solar cell field owing to its established, low-temperature fabrication processes. Excitement around alternative classes, particularly perovskites and the inorganic candidates, has recently arisen because of the major efficiency gains exhibited by these technologies. Importantly, each of these presents unique opportunities and challenges within the context of BIPV. This topic review provides an overview into the broader benefits of semi-transparent solar cells as building-integrated features, as well as providing the current development status into all of the major types of semi-transparent solar cells technologies.

  18. Process of making solar cell module

    Science.gov (United States)

    Packer, M.; Coyle, P.J.

    1981-03-09

    A process is presented for the manufacture of solar cell modules. A solution comprising a highly plasticized polyvinyl butyral is applied to a solar cell array. The coated array is dried and sandwiched between at last two sheets of polyvinyl butyral and at least two sheets of a rigid transparent member. The sandwich is laminated by the application of heat and pressure to cause fusion and bonding of the solar cell array with the rigid transparent members to produce a solar cell module.

  19. Perovskite solar cells: an emerging photovoltaic technology

    OpenAIRE

    Park, Nam-Gyu

    2015-01-01

    Perovskite solar cells based on organometal halides represent an emerging photovoltaic technology. Perovskite solar cells stem from dye-sensitized solar cells. In a liquid-based dye-sensitized solar cell structure, the adsorption of methylammonium lead halide perovskite on a nanocrystalline TiO2 surface produces a photocurrent with a power conversion efficiency (PCE) of around 3–4%, as first discovered in 2009. The PCE was doubled after 2 years by optimizing the perovskite coating conditions....

  20. Key Physical Mechanisms in Nanostructured Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Dr Stephan Bremner

    2010-07-21

    The objective of the project was to study both theoretically and experimentally the excitation, recombination and transport properties required for nanostructured solar cells to deliver energy conversion efficiencies well in excess of conventional limits. These objectives were met by concentrating on three key areas, namely, investigation of physical mechanisms present in nanostructured solar cells, characterization of loss mechanisms in nanostructured solar cells and determining the properties required of nanostructured solar cells in order to achieve high efficiency and the design implications.

  1. High Efficiency c-Silicon Solar Cells Based on Micro-Nanoscale Structure

    Science.gov (United States)

    2011-06-01

    growth of solar cell technology. Cell conversion efficiencies for current c-Si approaches vary from 12% to 17% (3). Module efficiencies tend to be...film materials: (1) amorphous Si (a-Si) (4), cadmium telluride ( CdTe ) (5), and copper indium diselenide (CIS) (6), which are the most mature thin...PV module technology—efficiency at the commercial module level, manufacturing cost, and outdoor module reliability. Many challenges must be overcome

  2. Surface Passivation for Silicon Heterojunction Solar Cells

    NARCIS (Netherlands)

    Deligiannis, D.

    2017-01-01

    Silicon heterojunction solar cells (SHJ) are currently one of the most promising solar cell technologies in the world. The SHJ solar cell is based on a crystalline silicon (c-Si) wafer, passivated on both sides with a thin intrinsic hydrogenated amorphous silicon (a-Si:H) layer. Subsequently, p-type

  3. Sheet plastic filters for solar cells

    Science.gov (United States)

    Wizenick, R. J.

    1972-01-01

    Poly(vinylidene fluoride) (PVF) film protects solar cells on Mars surface from radiation and prevents degradation of solar cell surfaces by Martian dust storms. PVF films may replace glass or quartz windows on solar cell arrays used to generate power on earth.

  4. Film adhesion in amorphous silicon solar cells

    Indian Academy of Sciences (India)

    A major issue encountered during fabrication of triple junction -Si solar cells on polyimide substrates is the adhesion of the solar cell thin films to the substrates. Here, we present our study of film adhesion in amorphous silicon solar cells made on different polyimide substrates (Kapton VN, Upilex-S and Gouldflex), and the ...

  5. Film adhesion in amorphous silicon solar cells

    Indian Academy of Sciences (India)

    TECS

    Abstract. A major issue encountered during fabrication of triple junction a-Si solar cells on polyimide sub- strates is the adhesion of the solar cell thin films to the substrates. Here, we present our study of film adhesion in amorphous silicon solar cells made on different polyimide substrates (Kapton VN, Upilex-S and ...

  6. Concentrated sunlight for organic solar cells

    DEFF Research Database (Denmark)

    Tromholt, Thomas

    2010-01-01

    Concentrated sunlight provides a novel approach to the study of the physical and electrical parameters of organic solar cells. The study of performance of organic solar cells at high solar concentrations provides insight into the physics, which cannot be studied with conventional solar simulators....... A high solar intensity study of inverted P3HT:PCBM solar cells is presented. Performance peak positions were found to be in the range of 1-5 suns, with smaller cells peaking at higher solar concentrations. Additionally, concentrated sunlight is demonstrated as a practical tool for accelerated stability...... studies of polymers for organic solar cells. Degradation was monitored by the evolution of the UV-vis absorption over time. Varying the solar intensity from 1 to 200 suns, the degradation rates were increased by more than a factor of 100 relative to degradation at 1 simulated sun. 5 different polymers...

  7. The fatty acid profile of rainbow trout liver cells modulates their tolerance to methylmercury and cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Ferain, Aline, E-mail: aline.ferain@uclouvain.be [Institute of Life Sciences, Université catholique de Louvain, Place Croix du Sud 2/L7.05.08, B-1348 Louvain-la-Neuve (Belgium); Bonnineau, Chloé [Institute of Life Sciences, Université catholique de Louvain, Place Croix du Sud 2/L7.05.08, B-1348 Louvain-la-Neuve (Belgium); Irstea, UR MALY, Centre de Lyon-Villeurbanne, rue de la Doua 5/32108, F-69616 Villeurbanne (France); Neefs, Ineke; Rees, Jean François; Larondelle, Yvan [Institute of Life Sciences, Université catholique de Louvain, Place Croix du Sud 2/L7.05.08, B-1348 Louvain-la-Neuve (Belgium); Schamphelaere, Karel A.C.De [Laboratory of Environmental Toxicology and Aquatic Ecology, Environmental Toxicology Unit, Ghent University, J. Plateaustraat 22, B-9000 Ghent (Belgium); Debier, Cathy [Institute of Life Sciences, Université catholique de Louvain, Place Croix du Sud 2/L7.05.08, B-1348 Louvain-la-Neuve (Belgium)

    2016-08-15

    Highlights: • The phospholipid composition of rainbow trout liver cells was successfully changed. • Cell phospholipids influenced methylmercury (MeHg) and cadmium (Cd) toxicity. • Cells enriched in 18:3n-3, 20:5n-3 or 22:5n-6 were more resistant to MeHg and Cd. • Cell enrichment in 22:6n-3 increased resistance to Cd but not MeHg. - Abstract: The polyunsaturated fatty acid (PUFA) composition of fish tissues, which generally reflects that of the diet, affects various cellular properties such as membrane structure and fluidity, energy metabolism and susceptibility to oxidative stress. Since these cellular parameters can play an important role in the cellular response to organic and inorganic pollutants, a variation of the PUFA supply might modify the toxicity induced by such xenobiotics. In this work, we investigated whether the cellular fatty acid profile has an impact on the in vitro cell sensitivity to two environmental pollutants: methylmercury and cadmium. Firstly, the fatty acid composition of the rainbow trout liver cell line RTL-W1 was modified by enriching the growth medium with either alpha-linolenic acid (ALA, 18:3n-3), eicosapentaenoic acid (EPA, 20:5n-3), docosahexaenoic acid (DHA, 22:6n-3), linoleic acid (LA, 18:2n-6), arachidonic acid (AA, 20:4n-6) or docosapentaenoic acid (DPA, 22:5n-6). These modified cells and their control (no PUFA enrichment) were then challenged for 24 h with increasing concentrations of methylmercury or cadmium. We observed that (i) the phospholipid composition of the RTL-W1 cells was profoundly modulated by changing the PUFA content of the growth medium: major modifications were a high incorporation of the supplemented PUFA in the cellular phospholipids, the appearance of direct elongation and desaturation metabolites in the cellular phospholipids as well as a change in the gross phospholipid composition (PUFA and monounsaturated fatty acid (MUFA) levels and n-3/n-6 ratio); (ii) ALA, EPA and DPA enrichment significantly

  8. Modeling and Design of a Thin-Film CdTe/Ge Tandem Solar Cell

    Science.gov (United States)

    Sharp, James; Pulfrey, David; Umana-Membreno, Gilberto A.; Faraone, Lorenzo; Dell, John M.

    2012-10-01

    Thin-film cadmium telluride (CdTe) solar cells have found widespread application, with current commercially available module efficiencies reaching 14.4% and production costs falling as low as US 0.75/W_p. Despite the proliferation of this technology, there have been comparatively few developments in research circles in recent years. Rather than attempt to further advance the materials science of CdTe solar cells, it is proposed to realize an efficiency improvement over conventional cells by means of a novel tandem structure. Three such structures are examined herein, and results of simulation using Synopsys Sentaurus TCAD are presented.

  9. A novel chlorophyll solar cell

    Science.gov (United States)

    Ludlow, J. C.

    The photosynthetic process is reviewed in order to produce a design for a chlorophyll solar cell. In a leaf, antenna chlorophyll absorbs light energy and conducts it to an energy trap composed of a protein and two chlorophyll molecules, which perform the oxidation-reduction chemistry. The redox potential of the trap changes from 0.4 to -0.6 V, which is sufficient to reduce nearby molecules with redox potentials in that range. The reduction occurs by transfer of an electron, and a chlorophyll solar cell would direct the transferred electron to a current carrier. Chlorophyll antenna and traps are placed on a metallic support immersed in an electron acceptor solution, and resulting electrons from exposure to light are gathered by a metallic current collector. Spinach chlorophyll extracted, purified, and applied in a cell featuring a Pt collector and an octane water emulsion resulted in intensity independent voltages.

  10. Cadmium toxicity in cultured tomato cells - Role of ethylene, proteases and oxidative stress in cell death signaling

    NARCIS (Netherlands)

    Iakimova, E.T.; Woltering, E.J.; Kapchina-Toteva, V.M.; Harren, F.J.M.; Cristescu, S.M.

    2008-01-01

    Our aim was to investigate the ability of cadmium to induce programmed cell death in tomato suspension cells and to determine the involvement of proteolysis, oxidative stress and ethylene. Tomato suspension cells were exposed to treatments with CdSO4 and cell death was calculated after fluorescein

  11. SLAM examination of solar cells and solar cell welds

    Science.gov (United States)

    Stella, P. M.; Vorres, C. L.; Yuhas, D. E.

    The scanning laser acoustic microscope (SLAM) has been evaluated for non-destructive examination of solar cells and interconnector bonds. Using this technique, it is possible to view through materials in order to reveal regions of discontinuity such as microcracks and voids. Of particular interest is the ability to evaluate, in a unique manner, the bonds produced by parallel gap welding. It is possible to not only determine the area and geometry of the bond between the tab and cell, but also to reveal any microcracks incurred during the welding. By correlating the SLAM results with conventional techniques of weld evaluation a more confident weld parameter optimization can be obtained.

  12. Three-Terminal Amorphous Silicon Solar Cells

    Directory of Open Access Journals (Sweden)

    Cheng-Hung Tai

    2011-01-01

    Full Text Available Many defects exist within amorphous silicon since it is not crystalline. This provides recombination centers, thus reducing the efficiency of a typical a-Si solar cell. A new structure is presented in this paper: a three-terminal a-Si solar cell. The new back-to-back p-i-n/n-i-p structure increased the average electric field in a solar cell. A typical a-Si p-i-n solar cell was also simulated for comparison using the same thickness and material parameters. The 0.28 μm-thick three-terminal a-Si solar cell achieved an efficiency of 11.4%, while the efficiency of a typical a-Si p-i-n solar cell was 9.0%. Furthermore, an efficiency of 11.7% was achieved by thickness optimization of the three-terminal solar cell.

  13. Extending the Endurance, Missions and Capabilities of Most UAVs Using Advanced Flexible/Ridged Solar Cells and New High Power Density Batteries Technology

    Science.gov (United States)

    2011-03-01

    Amperes-Hour AM Air mass AM0 Air mass 0 AM1.5 Air mass 1.5 a-Si Amorphous Silicon C/E Capacity/Energy CdS Cadmium Sulfide CdTe Cadmium...polycrystalline cadmium telluride ( CdTe ) and CIGS flexible cells, the back contacts are applied to the p-type semiconductor in both superstrate and...monolithically integrated sub- module CIGS flexible solar cell is shown in Figure 28. Figure 28. Typical process flow for preparing a flexible CIGS

  14. Apoptosis and necroptosis are induced in rainbow trout cell lines exposed to cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Krumschnabel, Gerhard, E-mail: Gerhard.Krumschnabel@i-med.ac.at [Division of Developmental Immunology, Biocenter, Medical University Innsbruck, Fritz-Preglstr. 3, Innsbruck (Austria); Ebner, Hannes L.; Hess, Michael W. [Division of Histology and Embryology, Medical University Innsbruck, Innsbruck (Austria); Villunger, Andreas [Division of Developmental Immunology, Biocenter, Medical University Innsbruck, Fritz-Preglstr. 3, Innsbruck (Austria)

    2010-08-01

    Cadmium is an important environmental toxicant that can kill cells. A number of studies have implicated apoptosis as well as necrosis and, most recently, a form of programmed necrosis termed necroptosis in the process of cadmium-mediated toxicity, but the exact mechanism remains ill-defined and may depend on the affected cell type. This study investigated which mode of cell death may be responsible for cell death induction in cadmium-exposed trout cell lines from gill and liver and if this cell death was sensitive to inhibitors of necroptosis or apoptosis, respectively. It was observed that intermediate levels of cadmium that killed approximately 50% of the cells over 96-120 h of exposure caused cell death that morphologically resembled apoptosis and was associated with an increase of apoptotic markers such as the number of cells with diminished DNA content (sub-G1 cells), condensed or fragmented nuclei, and elevation of caspase-3 activity. At the same time, however, cells also lost plasma membrane integrity, as indicated by uptake of propidium iodide, showed a decrease of ATP levels and mitochondrial membrane potential, and displayed cell swelling, signs associated with secondary necrosis, or equally possible, necroptotic cell death. Importantly, many of these alterations were at least partly inhibited by the necroptosis inhibitor necrostatin-1 and were to a lesser extent also sensitive to the pan-caspase inhibitor zVAD-fmk, indicating that multiple modes of cell death are concurrently induced in cadmium-exposed trout cells, including necroptosis and apoptosis. Cell death appeared to lack concurrent radical formation, consistent with genetically regulated necroptotic cell death, but was characterized by the rapid induction of DNA damage markers, and the early onset of disintegration of the Golgi complex. Comparative experiments evaluating copper-toxicity indicated that in comparison to cadmium much higher concentrations of this metal were required to induce cell

  15. Solar cell element

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Satoru; Matsukuma, Kunihiro; Kokuuchi, Shigeru; Morita, Keiichi; Yagi, Hideyuki.

    1989-07-17

    This invention aims to provide a soalr cell element with an easily formable electrode having an independent BSF and BSR. For this purpose, in this invention, a layer with high concentration of impurities (which functions as BSF on the opposite surface of the light-receiving surface) is partly and adjacently placed; a back electrode is made to have an ohmic resistance to the high-impurity layer; a metal oxide film is forther placed in other parts. By this, the functions of BSF and BSR are sufficiently utilized as a boundary surface between the high-impurity layer (BSF) and the semi-conductor substrate and the metal oxide film (BSR) are separated, thus enhancing the conversion efficiency. As for the patterns on the separated layers of BSF and BSR, various patterns are possible to be relized by using resist printing patterns. 3 figs.

  16. Perovskite Solar Cells: Potentials, Challenges, and Opportunities

    National Research Council Canada - National Science Library

    Ahmed, Muhammad Imran; Habib, Amir; Javaid, Syed Saad

    2015-01-01

      Heralded as a major scientific breakthrough of 2013, organic/inorganic lead halide perovskite solar cells have ushered in a new era of renewed efforts at increasing the efficiency and lowering the cost of solar energy...

  17. Hibiscus sabdariffa extractivities on cadmium-mediated alterations of human U937 cell viability and activation.

    Science.gov (United States)

    Okoko, Tebekeme; Ere, Diepreye

    2012-01-01

    To investigate the effect of the anthocyanin-rich extract of Hibiscus sabdariffa (H. sabdariffa) calyx on the viability of cadmium-treated U937 cells and cadmium-mediated activation of U937-derived macrophages. The macrophage cell line U937 was treated with cadmium (0.1 μ mol/L) and later incubated with the anthocyanin-rich extract and cell viability was assessed via trypan blue staining. In the other experiment, the U937 cells were transformed to the macrophage form by treatment with phorbol 12, myristate 13, and acetate and incubated with cadmium (10 μ mol/L). The anthocyanin-rich extract was added to the cells later and subsequently, the supernatant of each cell culture was analysed for the production of tumour necrosis factor-alpha (TNF-α), interleukin 1 (IL-1), interleukin 6 (IL-6), nitric oxide, and catalase activity as indices for the activation of macrophages. It revealed that the anthocynanin-rich extract significantly (P sabdariffa possesses significant immunoprotective effect. These corroborate the immense reported antioxidant and medicinal potential of the calyces of the plant which could be exploited for pharmacological and neutraceutical advantages. Copyright © 2012 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

  18. Thermochromic halide perovskite solar cells.

    Science.gov (United States)

    Lin, Jia; Lai, Minliang; Dou, Letian; Kley, Christopher S; Chen, Hong; Peng, Fei; Sun, Junliang; Lu, Dylan; Hawks, Steven A; Xie, Chenlu; Cui, Fan; Alivisatos, A Paul; Limmer, David T; Yang, Peidong

    2018-01-22

    Smart photovoltaic windows represent a promising green technology featuring tunable transparency and electrical power generation under external stimuli to control the light transmission and manage the solar energy. Here, we demonstrate a thermochromic solar cell for smart photovoltaic window applications utilizing the structural phase transitions in inorganic halide perovskite caesium lead iodide/bromide. The solar cells undergo thermally-driven, moisture-mediated reversible transitions between a transparent non-perovskite phase (81.7% visible transparency) with low power output and a deeply coloured perovskite phase (35.4% visible transparency) with high power output. The inorganic perovskites exhibit tunable colours and transparencies, a peak device efficiency above 7%, and a phase transition temperature as low as 105 °C. We demonstrate excellent device stability over repeated phase transition cycles without colour fade or performance degradation. The photovoltaic windows showing both photoactivity and thermochromic features represent key stepping-stones for integration with buildings, automobiles, information displays, and potentially many other technologies.

  19. Supramolecular photochemistry and solar cells

    Directory of Open Access Journals (Sweden)

    IHA NEYDE YUKIE MURAKAMI

    2000-01-01

    Full Text Available Supramolecular photochemistry as well as solar cells are fascinating topics of current interest in Inorganic Photochemistry and very active research fields which have attracted wide attention in last two decades. A brief outline of the investigations in these fields carried out in our Laboratory of Inorganic Photochemistry and Energy Conversion is given here with no attempt of an exhaustive coverage of the literature. The emphasis is placed on recent work and information on the above mentioned subjects. Three types of supramolecular systems have been the focus of this work: (i cage-type coordination compounds; (ii second-sphere coordination compounds, exemplified by ion-pair photochemistry of cobalt complexes and (iii covalently-linked systems. In the latter, modulation of the photoluminescence and photochemistry of some rhenium complexes are discussed. Solar energy conversion and development of thin-layer photoelectrochemical solar cells based on sensitization of nanocrystalline semiconductor films by some ruthenium polypyridyl complexes are presented as an important application that resulted from specifically engineered artificial assemblies.

  20. An investigation of arsenic-doped CdS/electrolyte solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Deshmukh, L.P.; Palwe, A.B. (Dept. of Applied Electronics, Shivaji Univ., Centre for Post-Graduate Studies, Solapur (India)); Sawant, V.S. (Dept. of Electronics, Y.C. Inst. of Science, Satara (India))

    1990-01-01

    An investigation of the photovoltaic properties of the cadmium sulphide semiconductor-liquid junction solar cell is presented. A well known chemical bath deposition technique was used for the deposition of thin film cadmium sulphide photoelectrodes. The photoelectrode was doped with trivalent arsenic in the concentration range 0.01-2 wt.%. Current-voltage and capacitance-voltage measurements were performed in a sulphide/polysulphide redox couple using a sensitized carbon counterelectrode. The performance of the electrochemical photovoltaic cell is examined in terms of the cell parameters, namely open-circuit voltage, short-circuit current, series and shunt resistances, efficiency, fill factor, junction ideality factors and flat band potential. An improvement in cell performance has been observed for a cell formed with 0.25 wt.% CdS:As photoelectrode. The results are supported by spectral response and optical absorption studies. (orig.).

  1. Energy Conversion: Nano Solar Cell

    Science.gov (United States)

    Yahaya, Muhammad; Yap, Chi Chin; Mat Salleh, Muhamad

    2009-09-01

    Problems of fossil-fuel-induced climate change have sparked a demand for sustainable energy supply for all sectors of economy. Most laboratories continue to search for new materials and new technique to generate clean energy at affordable cost. Nanotechnology can play a major role in solving the energy problem. The prospect for solar energy using Si-based technology is not encouraging. Si photovoltaics can produce electricity at 20-30 c//kWhr with about 25% efficiency. Nanoparticles have a strong capacity to absorb light and generate more electrons for current as discovered in the recent work of organic and dye-sensitized cell. Using cheap preparation technique such as screen-printing and self-assembly growth, organic cells shows a strong potential for commercialization. Thin Films research group at National University Malaysia has been actively involved in these areas, and in this seminar, we will present a review works on nanomaterials for solar cells and particularly on hybrid organic solar cell based on ZnO nanorod arrays. The organic layer consisting of poly[2-methoxy-5-(2-ethylhexyloxy)-1, 4-phenylenevinylene] (MEHPPV) and [6, 6]-phenyl C61-butyric acid 3-ethylthiophene ester (PCBE) was spin-coated on ZnO nanorod arrays. ZnO nanorod arrays were grown on FTO glass substrates which were pre-coated with ZnO nanoparticles using a low temperature chemical solution method. A gold electrode was used as the top contact. The device gave a short circuit current density of 2.49×10-4 mA/cm2 and an open circuit voltage of 0.45 V under illumination of a projector halogen light at 100 mW/cm2.

  2. Dye solar cells: a different approach to solar energy

    CSIR Research Space (South Africa)

    Le Roux, Lukas J

    2008-11-01

    Full Text Available An attractive and cheaper alternative to siliconbased photovoltaic (PV) cells for the conversion of solar light into electrical energy is to utilise dyeadsorbed, large-band-gap metal oxide materials such as TiO2 to absorb the solar light...

  3. Evaluation of Hybridoma B9 cell line handling of Cadmium in the ...

    African Journals Online (AJOL)

    6 (IL-6) was one of the responses examined to identify the mechanism by which IL-6 (at high concentration) was able to reverse cadmium inhibition of B9 cell line proliferation. Cellular metallothionein was assayed by Cd-haem method.

  4. An Evaluation of Kinetic Parameters of Cadmium and Copper Biosorption by Immobilized Cells

    Directory of Open Access Journals (Sweden)

    Nelly Georgieva

    2007-10-01

    Full Text Available Bioremediation is the use of living organisms to reduce or eliminate environmental hazards resulting from the accumulation of toxic chemicals and other hazardous wastes. This technology is based on the utilization of microorganisms to transform organic and inorganic compounds. The filamentous yeast Trichosporon cutaneum strain R57, immobilized and free cells was cultivated as batch culture on a liquid medium in the presence of various concentrations of cadmium and copper ions. The simultaneous uptake and accumulation of Cd2+ and Cu2+ ions by Tr. cutaneum cells depending on the initial concentration of Cd2+ and Cu2+ in the medium were studied. The potential use of the free and immobilized cells of Trichosporon cutaneum to remove cadmium and copper ions, from aqueous solutions was evaluated. Two important physicochemical aspects for the evaluation of the sorption process as a unit operation are the equilibrium of sorption and the kinetics. The Cd2+ and Cu2+ ions biosorption capacities of all tested adsorbent were presented as a function of the initial concentration of metal ions within the aqueous biosorption medium. The individual, as well as bicomponent sorption kinetics of copper and cadmium ions by immobilised cells of Trichosporon cutaneum R57 is presented. A second order kinetic model obtains kinetic parameters for the copper and cadmium ions.

  5. Design of cascaded low cost solar cell with CuO substrate

    Energy Technology Data Exchange (ETDEWEB)

    Samson, Mil' shtein; Anup, Pillai; Shiv, Sharma; Garo, Yessayan [Advanced Electronic Technology Center, ECE Dept., University of Massachusetts, Lowell, MA-01851 (United States)

    2013-12-04

    For many years the main focus of R and D in solar cells was the development of high-efficiency solar convertors. However with solar technology beginning to be a part of national grids and stand-alone power supplies for variety of individual customers, the emphasis has changed, namely, the cost per kilowatt- hour (kW-hr) started to be an important figure of merit. Although Si does dominate the market of solar convertors, this material has total cost of kilowatt-hour much higher than what the power grid is providing presently to customers. It is well known that the cost of raw semiconductor material is a major factor in formulation of the final cost of a solar cell. That motivated us to search and design a novel solar cell using cheap materials. The new p-i-n solar cell consists of hetero-structure cascade of materials with step by step decreasing energy gap. Since the lattice constant of these three materials do differ not more than 2%, the more expensive epitaxial fabrication methods can be used as well. It should be emphasized that designed solar cell is not a cascade of three solar cells connected in series. Our market study shows that Si solar panel which costs $250–400 / m{sup 2} leads to a cost of $0.12–0.30 / kW-hr. To the contrary, CuO based solar cells with Cadmium compounds on top, would cost $100 / m{sup 2}. This will allow the novel solar cell to produce electricity at a cost of $0.06–0.08 / kW-hr.

  6. Photon radiation effects on CdS/CuInSe2 thin film solar cells

    Science.gov (United States)

    Dursch, H.; Chen, W.; Rusell, D.

    1985-01-01

    The unknown tolerance of CuInSe2 cells to proton irradiation, was tested. It was shown that CdS/CuInSe2 solar cells have an inherent tolerance to irradiation by 1 MeV electrons up to at least 2 x 10 to the 16th power electrons/sq cm. Eleven, unencapsulated, 1 sq cm cells deposited on alumina substrates were irradiated with 1 MeV protons at normal incidence. The cells were exposed to six fluences ranging from 2.5 x 10 to the 10th power protons/sq cm to 5.0 x 10 to the 13th power protons/sq cm. After each interval of exposure, the cells were removed from the radiation chamber to undergo current/voltage characterization. It is shown that none of the cells electrical characteristics exhibited any degradation up to and including a fluence of 1 x 10 to the 11th power protons/sq cm. At fluences greater than this, the damage to the CuInSe2 cells V sub oc and fill factor (FF) was more severe than that exhibited by the Isc. The CuInSe2 cells proved to be approximately a factor of 50 more resistant to 1 MeV proton irradiation than silicon or gallium arsenide cells. Annealing of a CuInSe2 cell at 225 deg C for 6 minutes restored it to within 95% of its initial efficiency.

  7. Bypass diode for a solar cell

    Science.gov (United States)

    Rim, Seung Bum [Palo Alto, CA; Kim, Taeseok [San Jose, CA; Smith, David D [Campbell, CA; Cousins, Peter J [Menlo Park, CA

    2012-03-13

    Bypass diodes for solar cells are described. In one embodiment, a bypass diode for a solar cell includes a substrate of the solar cell. A first conductive region is disposed above the substrate, the first conductive region of a first conductivity type. A second conductive region is disposed on the first conductive region, the second conductive region of a second conductivity type opposite the first conductivity type.

  8. Coupling of Luminescent Solar Concentrators to Plasmonic Solar Cells

    Science.gov (United States)

    Wang, Shu-Yi

    To make inexpensive solar cells is a continuous goal for solar photovoltaic (PV) energy industry. Thin film solar cells of various materials have been developed and continue to emerge in order to replace bulk silicon solar cells. A thin film solar cell not only uses less material but also requires a less expensive refinery process. In addition, other advantages coming along with small thickness are higher open circuit voltage and higher conversion efficiency. However, thin film solar cells, especially those made of silicon, have significant optical losses. In order to address this problem, this thesis investigates the spectral coupling of thin films PV to luminescent solar concentrators (LSC). LSC are passive devices, consisting of plastic sheets embedded with fluorescent dyes which absorb part of the incoming radiation spectrum and emit at specific wavelength. The emitted light is concentrated by total internal reflection to the edge of the sheet, where the PVs are placed. Since the light emitted from the LSC edge is usually in a narrow spectral range, it is possible to employ diverse strategies to enhance PV absorption at the peak of the emission wavelength. Employing plasmonic nanostructures has been shown to enhance absorption of thin films via forward scattering, diffraction and localized surface plasmon. These two strategies are theoretically investigated here for improving the absorption and elevating the output power of a thin film solar cell. First, the idea of spectral coupling of luminescent solar concentrators to plasmonic solar cells is introduced to assess its potential for increasing the power output. This study is carried out employing P3HT/PC60BM organic solar cells and LSC with Lumogen Red dyes. A simplified spectral coupling analysis is employed to predict the power density, considering the output spectrum of the LSC equivalent to the emission spectrum of the dye and neglecting any angular dependence. Plasmonic tuning is conducted to enhance

  9. Solar Cells Using Quantum Funnels

    KAUST Repository

    Kramer, Illan J.

    2011-09-14

    Colloidal quantum dots offer broad tuning of semiconductor bandstructure via the quantum size effect. Devices involving a sequence of layers comprised of quantum dots selected to have different diameters, and therefore bandgaps, offer the possibility of funneling energy toward an acceptor. Here we report a quantum funnel that efficiently conveys photoelectrons from their point of generation toward an intended electron acceptor. Using this concept we build a solar cell that benefits from enhanced fill factor as a result of this quantum funnel. This concept addresses limitations on transport in soft condensed matter systems and leverages their advantages in large-area optoelectronic devices and systems. © 2011 American Chemical Society.

  10. THIN FILM A-Slzfl SOLAR CELLS

    African Journals Online (AJOL)

    circuit current were compared to the parameters of crystalline silicon pit-junction solar cells. The effect of irradiance and spectral illumination on the cell performance was investigated. Finally, the applicability of the investigated thin. film a-Si:H solar cells for its practical operation in Ethiopia is discussed. Key words/phrases: ...

  11. Device operation of organic tandem solar cells

    NARCIS (Netherlands)

    Hadipour, A.; de Boer, B.; Blom, P. W. M.

    2008-01-01

    A generalized methodology is developed to obtain the current-voltage characteristic of polymer tandem solar cells by knowing the electrical performance of both sub cells. We demonstrate that the electrical characteristics of polymer tandem solar cells are correctly predicted for both the series and

  12. Solar power satellites - Heat engine or solar cells

    Science.gov (United States)

    Oman, H.; Gregory, D. L.

    1978-01-01

    A solar power satellite is the energy-converting element of a system that can deliver some 10 GW of power to utilities on the earth's surface. We evaluated heat engines and solar cells for converting sunshine to electric power at the satellite. A potassium Rankine cycle was the best of the heat engines, and 50 microns thick single-crystal silicon cells were the best of the photovoltaic converters. Neither solar cells nor heat engines had a clear advantage when all factors were considered. The potassium-turbine power plant, however, was more difficult to assemble and required a more expensive orbital assembly base. We therefore based our cost analyses on solar-cell energy conversion, concluding that satellite-generated power could be delivered to utilities for around 4 to 5 cents a kWh.

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

    NARCIS (Netherlands)

    Lu, J.; Liu, Wei; Kovalgin, Alexeij Y.; Sun, Yun; Schmitz, Jurriaan

    2011-01-01

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

  14. Cadmium interaction with microalgal cells, cyanobacterial cells, and seaweeds; toxicology and biotechnological potential for wastewater treatment.

    Science.gov (United States)

    da Costa, Antonio Carlos Augusto; de França, Francisca Pessôa

    2003-01-01

    The accumulation of cadmium (Cd) by Tetraselmis chuii and Spirulina maxima was studied with dead and growing cells. Results indicated that the 2 microorganisms accumulated Cd by 2 different means according to the mechanisms involved-metabolism-dependent or metabolism-independent sorption. The mechanism involved in Cd accumulation on Tetraselmis chuii was restricted to surface phenomena, while in Spirulina maxima, Cd was accumulated on different layers of the cyanobacterium surface. In order to select a suitable immobilization support for the cells, several seaweeds were tested. Two types of seaweed were selected for experiments, using a small continuous pilot unit: Sargassum sp., a strong Cd adsorber, and Ulva sp., a poor one. The column reactors of the continuous system were filled with the algal supports and covered with dense microbial biofilms of Tetraselmis chuii or Spirulina maxima. The results obtained proved the success of the association between living microbial cells and dead seaweeds for operation of the continuous system.

  15. Front contact solar cell with formed emitter

    Science.gov (United States)

    Cousins, Peter John [Menlo Park, CA

    2012-07-17

    A bipolar solar cell includes a backside junction formed by an N-type silicon substrate and a P-type polysilicon emitter formed on the backside of the solar cell. An antireflection layer may be formed on a textured front surface of the silicon substrate. A negative polarity metal contact on the front side of the solar cell makes an electrical connection to the substrate, while a positive polarity metal contact on the backside of the solar cell makes an electrical connection to the polysilicon emitter. An external electrical circuit may be connected to the negative and positive metal contacts to be powered by the solar cell. The positive polarity metal contact may form an infrared reflecting layer with an underlying dielectric layer for increased solar radiation collection.

  16. Recent advances of flexible hybrid perovskite solar cells

    Science.gov (United States)

    Shin, Dong Hee; Heo, Jin Hyuck; Im, Sang Hyuk

    2017-11-01

    Recently, hybrid perovskite solar cells have attracted great interest because they can be fabricated to low cost, flexible, and highly efficient solar cells. Here, we introduced recent advances of flexible hybrid perovskite solar cells. We introduced research background of flexible perovskite solar cells in introduction part. Then we composed the main body to i) structure and properties of hybrid perovskite solar cells, ii) why flexible hybrid perovskite solar cells are important?, iii) transparent conducting oxide (TCO) based flexible hybrid perovskite solar cells, and iv) TCO-free transparent conducting electrode (TCE) based flexible hybrid perovskite solar cells. Finally, we summarized research outlook of flexible hybrid perovskite solar cells.

  17. Life Cycle Assessment of Titania Perovskite Solar Cell Technology for Sustainable Design and Manufacturing.

    Science.gov (United States)

    Zhang, Jingyi; Gao, Xianfeng; Deng, Yelin; Li, Bingbing; Yuan, Chris

    2015-11-01

    Perovskite solar cells have attracted enormous attention in recent years due to their low cost and superior technical performance. However, the use of toxic metals, such as lead, in the perovskite dye and toxic chemicals in perovskite solar cell manufacturing causes grave concerns for its environmental performance. To understand and facilitate the sustainable development of perovskite solar cell technology from its design to manufacturing, a comprehensive environmental impact assessment has been conducted on titanium dioxide nanotube based perovskite solar cells by using an attributional life cycle assessment approach, from cradle to gate, with manufacturing data from our laboratory-scale experiments and upstream data collected from professional databases and the literature. The results indicate that the perovskite dye is the primary source of environmental impact, associated with 64.77% total embodied energy and 31.38% embodied materials consumption, contributing to more than 50% of the life cycle impact in almost all impact categories, although lead used in the perovskite dye only contributes to about 1.14% of the human toxicity potential. A comparison of perovskite solar cells with commercial silicon and cadmium-tellurium solar cells reveals that perovskite solar cells could be a promising alternative technology for future large-scale industrial applications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. N/P GaAs concentrator solar cells with an improved grid and bushbar contact design

    Science.gov (United States)

    Desalvo, G. C.; Mueller, E. H.; Barnett, A. M.

    1985-01-01

    The major requirements for a solar cell used in space applications are high efficiency at AMO irradiance and resistance to high energy radiation. Gallium arsenide, with a band gap of 1.43 eV, is one of the most efficient sunlight to electricity converters (25%) when the the simple diode model is used to calculate efficiencies at AMO irradiance, GaAs solar cells are more radiation resistant than silicon solar cells and the N/P GaAs device has been reported to be more radiation resistant than similar P/N solar cells. This higher resistance is probably due to the fact that only 37% of the current is generated in the top N layer of the N/P cell compared to 69% in the top layer of a P/N solar cell. This top layer of the cell is most affected by radiation. It has also been theoretically calculated that the optimized N/P device will prove to have a higher efficiency than a similar P/N device. The use of a GaP window layer on a GaAs solar cell will avoid many of the inherent problems normally associated with a GaAlAs window while still proving good passivation of the GaAs surface. An optimized circular grid design for solar cell concentrators has been shown which incorporates a multi-layer metallization scheme. This multi-layer design allows for a greater current carrying capacity for a unit area of shading, which results in a better output efficiency.

  19. Integration of Solar Cells on Top of CMOS Chips Part I: a-Si Solar Cells

    NARCIS (Netherlands)

    Lu, J.; Kovalgin, Alexeij Y.; van der Werf, Karine H.M.; Schropp, Ruud E.I.; Schmitz, Jurriaan

    2011-01-01

    We present the monolithic integration of deepsubmicrometer complementary metal–oxide–semiconductor (CMOS) microchips with a-Si:H solar cells. Solar cells are manufactured directly on the CMOS chips. The microchips maintain comparable electronic performance, and the solar cells show efficiency values

  20. Effects of cadmium on cell proliferation, apoptosis, and proto-oncogene expression in zebrafish liver cells

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ying Ying; Zhu, Jin Yong; Chan, King Ming, E-mail: kingchan@cuhk.edu.hk

    2014-12-15

    Highlights: • Cd stimulated ZFL cell proliferation with decreasing apoptotic cell numbers. • Cd down regulated p53 and RAD51. • Cd up regulated immediate early cancer genes of GADD45 and growth factors. • Cd promoted tumorigenic effects in ZFL cells. - Abstract: Cadmium (Cd) is one of the major transitional metal that has toxic effects in aquatic organisms and their associated ecosystem; however, its hepatic toxicity and carcinogenicity are not very well characterized. We used a zebrafish liver (ZFL) cell line as a model to investigate the mechanism of Cd-induced toxicity on hepatocytes. Our results showed that Cd can be effectively accumulated in ZFL cells in our exposure experiments. Cell cytotoxicity assays and flow cytometer measurements revealed that Cd{sup 2+} stimulated ZFL cell proliferation with decreasing apoptotic cell numbers indicating potentially tumorigenic effects of Cd in ZFL cells. Gene expression profiles also indicated that Cd downregulated oncogenes p53 and rad51 and upregulated immediate response oncogenes, growth arrest and DNA damage-inducible (gadd45) genes, and growth factors. We also found dramatic changes in the gene expression of c-jun and igf1rb at different exposure time points, supporting the notion that potentially tumorigenic of Cd-is involved in the activation of immediate early genes or genes related to apoptosis in cancer promotion.

  1. The effects of cadmium chloride on secondary metabolite production in Vitis vinifera cv. cell suspension cultures.

    Science.gov (United States)

    Cetin, Emine Sema; Babalik, Zehra; Hallac-Turk, Filiz; Gokturk-Baydar, Nilgun

    2014-09-23

    Plant secondary metabolites are possess several biological activities such as anti-mutagenic, anti-carcinogenic, anti-aging, etc. Cell suspension culture is one of the most effective systems to produce secondary metabolites. It is possible to increase the phenolic compounds and tocopherols by using cell suspensions. Studies on tocopherols production by cell suspension cultures are seldom and generally focused on seed oil plants. Although fresh grape, grape seed, pomace and grape seed oil had tocopherols, with our best knowledge, there is no research on tocopherol accumulation in the grape cell suspension cultures. In this study, it was aimed to determine the effects of cadmium chloride treatments on secondary metabolite production in cell suspension cultures of grapevine. Cell suspensions initiated from callus belonging to petiole tissue was used as a plant material. Cadmium chloride was applied to cell suspension cultures in different concentration (1.0 mM and 1.5 mM) to enhance secondary metabolite (total phenolics, total flavanols, total flavonols, trans-resveratrol, and α-, β-, γ- δ-tocopherols) production. Cells were harvested at two days intervals until the 6th day of cultures. Amounts of total phenolics, total flavanols and total flavonols; trans-resveratrol and tocopherols (α-, β-, γ- and δ-tocopherols) and dry cell weights were determined in the harvested cells. Phenolic contents were significantly affected by the sampling time and cadmium concentrations. The highest values of total phenolic (168.82 mg/100 g), total flavanol (15.94 mg/100 g), total flavonol (14.73 mg/100 g) and trans-resveratrol (490.76 μg/100 g) were found in cells treated with 1.0 mM CdCl2 and harvested at day 2. Contents of tocopherols in the cells cultured in the presence of 1.0 mM CdCl2 gradually increased during the culture period and the highest values of α, β and γ tocopherols (145.61, 25.52 and 18.56 μg/100 g) were detected in the cell cultures collected at day 6

  2. The effects of cadmium chloride on secondary metabolite production in Vitis vinifera cv. cell suspension cultures

    Directory of Open Access Journals (Sweden)

    Emine Sema Cetin

    2014-01-01

    Full Text Available BACKGROUND: Plant secondary metabolites are possess several biological activities such as anti-mutagenic, anti-carcinogenic, anti-aging, etc. Cell suspension culture is one of the most effective systems to produce secondary metabolites. It is possible to increase the phenolic compounds and tocopherols by using cell suspensions. Studies on tocopherols production by cell suspension cultures are seldom and generally focused on seed oil plants. Although fresh grape, grape seed, pomace and grape seed oil had tocopherols, with our best knowledge, there is no research on tocopherol accumulation in the grape cell suspension cultures. In this study, it was aimed to determine the effects of cadmium chloride treatments on secondary metabolite production in cell suspension cultures of grapevine. Cell suspensions initiated from callus belonging to petiole tissue was used as a plant material. Cadmium chloride was applied to cell suspension cultures in different concentration (1.0 mM and 1.5 mM to enhance secondary metabolite (total phenolics, total flavanols, total flavonols, trans-resveratrol, and α-, β-, γ- δ-tocopherols production. Cells were harvested at two days intervals until the 6th day of cultures. Amounts of total phenolics, total flavanols and total flavonols; trans-resveratrol and tocopherols (α-, β-, γ- and δ-tocopherols and dry cell weights were determined in the harvested cells. RESULTS: Phenolic contents were significantly affected by the sampling time and cadmium concentrations. The highest values of total phenolic (168.82 mg/100 g, total flavanol (15.94 mg/100 g, total flavonol (14.73 mg/100 g and trans-resveratrol (490.76 µg/100 g were found in cells treated with 1.0 mM CdCl2 and harvested at day 2. Contents of tocopherols in the cells cultured in the presence of 1.0 mM CdCl2 gradually increased during the culture period and the highest values of α, β and γ tocopherols (145.61, 25.52 and 18.56 µg/100 g were detected in the cell

  3. Perovskite Solar Cells with Large-Area CVD-Graphene for Tandem Solar Cells.

    Science.gov (United States)

    Lang, Felix; Gluba, Marc A; Albrecht, Steve; Rappich, Jörg; Korte, Lars; Rech, Bernd; Nickel, Norbert H

    2015-07-16

    Perovskite solar cells with transparent contacts may be used to compensate for thermalization losses of silicon solar cells in tandem devices. This offers a way to outreach stagnating efficiencies. However, perovskite top cells in tandem structures require contact layers with high electrical conductivity and optimal transparency. We address this challenge by implementing large-area graphene grown by chemical vapor deposition as a highly transparent electrode in perovskite solar cells, leading to identical charge collection efficiencies. Electrical performance of solar cells with a graphene-based contact reached those of solar cells with standard gold contacts. The optical transmission by far exceeds that of reference devices and amounts to 64.3% below the perovskite band gap. Finally, we demonstrate a four-terminal tandem device combining a high band gap graphene-contacted perovskite top solar cell (Eg = 1.6 eV) with an amorphous/crystalline silicon bottom solar cell (Eg = 1.12 eV).

  4. Influence of photon recycling effects in the operation and design of GaAs solar cells; Influencia del reciclaje de fotones en el funcionamiento y del diseno de las celulas solares de Arsenico de Galio

    Energy Technology Data Exchange (ETDEWEB)

    Balenzategui Manzanares, J. L.

    2005-07-01

    Photon recycling (PR) is the process by which photons internally emitted in a semiconductor can be re-absorbed by the material, giving as result new electron-hole pairs. Although this process has been receiving some international research from the Sixties, because their effects revealed as relevant in certain devices and materials (as in gallium arsenide), its influence in the operation of solar cells has been scarcely considered in the past. Thus deposited it has been demonstrated that one of its major effects is an enhancement of the radiative carrier lifetine, photon recycling is not usually taken into account in photovoltaic, neither in device modelling and simulation, nor from the perspective of taking advantage of the phenomenon to improve the efficiency of solar cells. This work describes the results of our investigations in the field of photon recycling. (Author)

  5. Monolithic cells for solar fuels.

    Science.gov (United States)

    Rongé, Jan; Bosserez, Tom; Martel, David; Nervi, Carlo; Boarino, Luca; Taulelle, Francis; Decher, Gero; Bordiga, Silvia; Martens, Johan A

    2014-12-07

    Hybrid energy generation models based on a variety of alternative energy supply technologies are considered the best way to cope with the depletion of fossil energy resources and to limit global warming. One of the currently missing technologies is the mimic of natural photosynthesis to convert carbon dioxide and water into chemical fuel using sunlight. This idea has been around for decades, but artificial photosynthesis of organic molecules is still far away from providing real-world solutions. The scientific challenge is to perform in an efficient way the multi-electron transfer reactions of water oxidation and carbon dioxide reduction using holes and single electrons generated in an illuminated semiconductor. In this tutorial review the design of photoelectrochemical (PEC) cells that combine solar water oxidation and CO2 reduction is discussed. In such PEC cells simultaneous transport and efficient use of light, electrons, protons and molecules has to be managed. It is explained how efficiency can be gained by compartmentalisation of the water oxidation and CO2 reduction processes by proton exchange membranes, and monolithic concepts of artificial leaves and solar membranes are presented. Besides transferring protons from the anode to the cathode compartment the membrane serves as a molecular barrier material to prevent cross-over of oxygen and fuel molecules. Innovative nano-organized multimaterials will be needed to realise practical artificial photosynthesis devices. This review provides an overview of synthesis techniques which could be used to realise monolithic multifunctional membrane-electrode assemblies, such as Layer-by-Layer (LbL) deposition, Atomic Layer Deposition (ALD), and porous silicon (porSi) engineering. Advances in modelling approaches, electrochemical techniques and in situ spectroscopies to characterise overall PEC cell performance are discussed.

  6. Dye-sensitised solar cell (artificial photosynthesis)

    CSIR Research Space (South Africa)

    Le Roux, Lukas J

    2005-07-01

    Full Text Available A novel system that harnesses solar energy is the nano-crystalline TiO dye-sensitised solar cell (DSC), in conjunction with several new concepts, such as nanotechnology and molecular devices. An efficient and low-cost cell can be produced by using...

  7. Perovskite solar cells: Different facets of performance

    Science.gov (United States)

    Eperon, Giles E.; Ginger, David S.

    2016-08-01

    The electronic properties of halide perovskites vary significantly between crystalline grains, but the impact of this heterogeneity on solar cell performance is unclear. Now, this variability is shown to limit the photovoltaic properties of solar cells, and its origins are linked to differing properties between crystal facets.

  8. Fullerene surfactants and their use in polymer solar cells

    Science.gov (United States)

    Jen, Kwan-Yue; Yip, Hin-Lap; Li, Chang-Zhi

    2015-12-15

    Fullerene surfactant compounds useful as interfacial layer in polymer solar cells to enhance solar cell efficiency. Polymer solar cell including a fullerene surfactant-containing interfacial layer intermediate cathode and active layer.

  9. Electrolyte Management Considerations in Modern Nickel Hydrogen and Nickel Cadmium Cell and Battery Designs

    Science.gov (United States)

    Thaller, Lawrence H.; Zimmerman, Albert H.

    1996-01-01

    This paper reviews three general areas where the potassium ion content can impact the performance and life of nickel hydrogen and nickel cadmium cells. Sample calculations of the concentration or volume changes that can take place within operating cells are presented. With the aid of an accurate model of an operating cell or battery, the impact of changes of potassium ion content within a potential cell design can be estimated. All three of these areas are directly related to the volume tolerance and pore size engineering aspects of the components used in the cell or battery design.

  10. Hydrogen sulfide alleviates cadmium toxicity through regulations of cadmium transport across the plasma and vacuolar membranes in Populus euphratica cells.

    Science.gov (United States)

    Sun, Jian; Wang, Ruigang; Zhang, Xuan; Yu, Yicheng; Zhao, Rui; Li, Zongyun; Chen, Shaoliang

    2013-04-01

    Hydrogen sulfide (H2S) is emerging as a novel signalling molecule involved in plant growth and responses against abiotic stresses. However, little information is known about its role in cadmium (Cd) detoxification. In the present study, the effects of H2S on Cd toxicity were investigated in Populus euphratica cells using fluorescence imaging technique and a non-invasive vibrating ion-selective microelectrode. Pretreatment with a H2S donor, sodium hydrosulfide (NaHS), significantly mitigated the Cd-induced programmed cell death in P. euphratica cells. The alleviation effect of NaHS was more pronounced at 50-100 μM as compared to low (25 μM) and high doses (200 μM). Under Cd stress, total activities of antioxidant enzymes, such as ascorbate peroxidase, catalase and glutathione reductase, were significantly enhanced in NaHS-treated cells, leading to a decline of H2O2 accumulation and lipid peroxidation. Moreover, NaHS reduced Cd accumulation in the cytoplasm but increased the fraction of Cd in the vacuole. Cd flux profiles revealed that H2S inhibited the Cd influx through the plasma membrane (PM) calcium channels that activated by H2O2. NaHS enhanced Cd influx into the vacuole, and the Cd influx was dependent on the pH gradients across the tonoplast. Taken together, these results suggest that H2S alleviates Cd toxicity via the improvement of antioxidant system and cellular Cd homeostasis. The up-regulation of antioxidant enzymes by H2S reduced the accumulation of H2O2, and thus decreased Cd influx through the H2O2-activated PM calcium channels. The H2S-simulated vacuolar Cd sequestration was presumably due to the activation of tonoplast Cd(2+)/H(+) antiporters. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  11. Methodologies for high efficiency perovskite solar cells.

    Science.gov (United States)

    Park, Nam-Gyu

    2016-01-01

    Since the report on long-term durable solid-state perovskite solar cell in 2012, perovskite solar cells based on lead halide perovskites having organic cations such as methylammonium CH3NH3PbI3 or formamidinium HC(NH2)2PbI3 have received great attention because of superb photovoltaic performance with power conversion efficiency exceeding 22 %. In this review, emergence of perovskite solar cell is briefly introduced. Since understanding fundamentals of light absorbers is directly related to their photovoltaic performance, opto-electronic properties of organo lead halide perovskites are investigated in order to provide insight into design of higher efficiency perovskite solar cells. Since the conversion efficiency of perovskite solar cell is found to depend significantly on perovskite film quality, methodologies for fabricating high quality perovskite films are particularly emphasized, including various solution-processes and vacuum deposition method.

  12. Organic Based Solar Cells with Morphology Control

    DEFF Research Database (Denmark)

    Andersen, Thomas Rieks

    The field of organic solar cells has in the last years gone through an impressive development with efficiencies reported up to 12 %. For organic solar cells to take the leap from primarily being a laboratory scale technology to being utilized as renewable energy source, several issues need...... Microscopy and as solar cells in a blend with PCBM. It was concluded that these particles did not show a potential large enough for continuous work due to a high material loss and low efficiency when applied in solar cells. The second method to achieve was preparation of pre-arranged morphology organic...... nanoparticles consisting of a blend of donor and acceptor in an aqueous dispersion, thereby addressing two of the issues remaining in the field of organic solar cells. This approach was used on six different polymers, which all had the ability to prepare aqueous nanoparticle inks. The morphology...

  13. High Radiation Resistance IMM Solar Cell

    Science.gov (United States)

    Pan, Noren

    2015-01-01

    Due to high launch costs, weight reduction is a key driver for the development of new solar cell technologies suitable for space applications. This project is developing a unique triple-junction inverted metamorphic multijunction (IMM) technology that enables the manufacture of very lightweight, low-cost InGaAsP-based multijunction solar cells. This IMM technology consists of indium (In) and phosphorous (P) solar cell active materials, which are designed to improve the radiation-resistant properties of the triple-junction solar cell while maintaining high efficiency. The intrinsic radiation hardness of InP materials makes them of great interest for building solar cells suitable for deployment in harsh radiation environments, such as medium Earth orbit and missions to the outer planets. NASA Glenn's recently developed epitaxial lift-off (ELO) process also will be applied to this new structure, which will enable the fabrication of the IMM structure without the substrate.

  14. Achieving 15% Tandem Polymer Solar Cells

    Science.gov (United States)

    2015-06-23

    final support also enabled us to explore novel hybrid perovskite solar cells in depth. For example, single junction cell efficiency of 19.3% under...novel hybrid perovskite solar cells in depth. For example, single junction cell efficiency of 19.3% under reverse bias was achieved and the results...3 In a second effort, a monolithic integration of perovskite and LBG polymer:fullerene subcells into a tandem structure is realized through a full

  15. Luminescence-based whole-cell-sensing systems for cadmium and lead using genetically engineered bacteria.

    Science.gov (United States)

    Shetty, Ranjit S; Deo, Sapna K; Shah, Puja; Sun, Yan; Rosen, Barry P; Daunert, Sylvia

    2003-05-01

    Whole-cell-based sensing systems that respond to cadmium and lead ions have been designed and developed using genetically engineered bacteria. These systems take advantage of the ability of certain bacteria to survive in environments polluted with cadmium and lead ions. The bacteria used in this investigation have been genetically engineered to produce reporter proteins in response to the toxic ions. This was achieved by modifying a strain of Escherichia colito harbor plasmids pYSC1 and pYS2/pYSG1. In these dual-plasmid-based sensing systems, the expression of the reporters beta-galactosidase and red-shifted green fluorescent protein (rs-GFP) was controlled by CadC, the regulatory protein of the cad operon. Regulation of the expression of the reporter proteins is related to the amount of cadmium and lead ions employed to induce the bacteria. The bacterial sensing systems were found to respond to cadmium, lead, and zinc ions, and had no significant response to nickel, copper, manganese, and cobalt.

  16. Some investigations on thickness-dependent electrical behaviour of CdS:As/electrolyte solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Deshmukh, L.P. (Dept. of Applied Electronics, Shivaji Univ., Solapur (India)); Hankare, P.P. (Dept. of Polymer Chemistry, Shivaji Univ., Solapur (India)); Sawant, V.S. (Dept. of Electronics, Y.C. Inst. of Science, Satara (India))

    1991-12-01

    An investigation has been made into the effect of photoelectrode thickness of the photovoltaic properties of cadmium sulphide/electrolyte solar cells. CdS photoelectrodes of various thicknesses doped with 0.25wt.% arsenic were prepared by a chemical deposition process on plane mirror smooth stainless steel substrates. An electrode/electrolyte junction cell was designed for use in a glass cuvette and has been analysed in terms of its electrical parameters. The thickness of the photoelectrode was found to cause significant changes in cell parameters such as short-circuit current, open-circuit voltage, series and shunt resistances, fill factor, junction quality factors and flat band potential. (orig.).

  17. Coating Processes Boost Performance of Solar Cells

    Science.gov (United States)

    2012-01-01

    NASA currently has spacecraft orbiting Mercury (MESSENGER), imaging the asteroid Vesta (Dawn), roaming the red plains of Mars (the Opportunity rover), and providing a laboratory for humans to advance scientific research in space (the International Space Station, or ISS). The heart of the technology that powers those missions and many others can be held in the palm of your hand - the solar cell. Solar, or photovoltaic (PV), cells are what make up the panels and arrays that draw on the Sun s light to generate electricity for everything from the Hubble Space Telescope s imaging equipment to the life support systems for the ISS. To enable NASA spacecraft to utilize the Sun s energy for exploring destinations as distant as Jupiter, the Agency has invested significant research into improving solar cell design and efficiency. Glenn Research Center has been a national leader in advancing PV technology. The Center s Photovoltaic and Power Technologies Branch has conducted numerous experiments aimed at developing lighter, more efficient solar cells that are less expensive to manufacture. Initiatives like the Forward Technology Solar Cell Experiments I and II in which PV cells developed by NASA and private industry were mounted outside the ISS have tested how various solar technologies perform in the harsh conditions of space. While NASA seeks to improve solar cells for space applications, the results are returning to Earth to benefit the solar energy industry.

  18. Solar-electrochemical power system for a Mars mission

    Science.gov (United States)

    Withrow, Colleen A.; Morales, Nelson

    1994-12-01

    This report documents a sizing study of a variety of solar electrochemical power systems for the intercenter NASA study known as 'Mars Exploration Reference Mission'. Power systems are characterized for a variety of rovers, habitation modules, and space transport vehicles based on requirements derived from the reference mission. The mission features a six-person crew living on Mars for 500 days. Mission power requirements range from 4 kWe to 120 kWe. Primary hydrogen and oxygen fuel cells, regenerative hydrogen and oxygen fuel cells, sodium sulfur batteries advanced photovoltaic solar arrays of gallium arsenide on germanium with tracking and nontracking mechanisms, and tent solar arrays of gallium arsenide on germanium are evaluated and compared.

  19. Tandem photovoltaic solar cells and increased solar energy conversion efficiency

    Science.gov (United States)

    Loferski, J. J.

    1976-01-01

    Tandem photovoltaic cells, as proposed by Jackson (1955) to increase the efficiency of solar energy conversion, involve the construction of a system of stacked p/n homojunction photovoltaic cells composed of different semiconductors. It had been pointed out by critics, however, that the total power which could be extracted from the cells in the stack placed side by side was substantially greater than the power obtained from the stacked cells. A reexamination of the tandem cell concept in view of the development of the past few years is conducted. It is concluded that the use of tandem cell systems in flat plate collectors, as originally envisioned by Jackson, may yet become feasible as a result of the development of economically acceptable solar cells for large scale terrestrial power generation.

  20. Glucose alleviates cadmium toxicity by increasing cadmium fixation in root cell wall and sequestration into vacuole in Arabidopsis.

    Science.gov (United States)

    Shi, Yuan-Zhi; Zhu, Xiao-Fang; Wan, Jiang-Xue; Li, Gui-Xin; Zheng, Shao-Jian

    2015-10-01

    Glucose (Glu) is involved in not only plant physiological and developmental events but also plant responses to abiotic stresses. Here, we found that the exogenous Glu improved root and shoot growth, reduced shoot cadmium (Cd) concentration, and rescued Cd-induced chlorosis in Arabidopsis thaliana (Columbia ecotype, Col-0) under Cd stressed conditions. Glucose increased Cd retained in the roots, thus reducing its translocation from root to shoot significantly. The most Cd retained in the roots was found in the hemicellulose 1. Glucose combined with Cd (Glu + Cd) treatment did not affect the content of pectin and its binding capacity of Cd while it increased the content of hemicelluloses 1 and the amount of Cd retained in it significantly. Furthermore, Leadmium Green staining indicated that more Cd was compartmented into vacuoles in Glu + Cd treatment compared with Cd treatment alone, which was in accordance with the significant upregulation of the expression of tonoplast-localized metal transporter genes, suggesting that compartmentation of Cd into vacuoles also contributes to the Glu-alleviated Cd toxicity. Taken together, we demonstrated that Glu-alleviated Cd toxicity is mediated through increasing Cd fixation in the root cell wall and sequestration into the vacuoles. © 2014 Institute of Botany, Chinese Academy of Sciences.

  1. Indium Arsenide Nanowires

    DEFF Research Database (Denmark)

    Madsen, Morten Hannibal

    -ray diffraction. InAs NWs can be used in a broad range of applications, including detectors, high speed electronics and low temperature transport measurements, but in this thesis focus will be put on biological experiments on living cells. Good control of Au-assisted InAs NW growth has been achieved...... by a systematic study to optimize the growth conditions; first the Au deposition, then the growth temperature and finally the beam fluxes. For further control of the growth, Au droplets have been positioned with electron beam lithography and large scale arrays with a > 99 % yield have been made on 2 inch...... and its dependence on growth parameters. By fabricating the NWs on silicon-on-insulator substrates we demonstrate electrically addressable NWs that are still standing vertically on the substrate and can potentially be used for intra-cellular recordings. Devices for biological experiments using vertically...

  2. Solar Cell Panel and the Method for Manufacturing the Same

    Science.gov (United States)

    Richards, Benjamin C. (Inventor); Sarver, Charles F. (Inventor); Naidenkova, Maria (Inventor)

    2016-01-01

    According to an aspect of an embodiment of the present disclosure, there is provided a solar cell panel and a method for manufacturing the same. The solar cell panel comprises: a solar cell for generating electric power from sunlight; a coverglass for covering the solar cell; transparent shims, which are disposed between the solar cell and the coverglass at the points where the distance between the solar cell and the coverglass needs to be controlled, and form a space between the solar cell and the coverglass; and adhesive layer, which fills the space between the solar cell and the coverglass and has the thickness the same as that of the transparent shims.

  3. Semiconductor quantum dot-sensitized solar cells

    Directory of Open Access Journals (Sweden)

    Jianjun Tian

    2013-10-01

    Full Text Available Semiconductor quantum dots (QDs have been drawing great attention recently as a material for solar energy conversion due to their versatile optical and electrical properties. The QD-sensitized solar cell (QDSC is one of the burgeoning semiconductor QD solar cells that shows promising developments for the next generation of solar cells. This article focuses on recent developments in QDSCs, including 1 the effect of quantum confinement on QDSCs, 2 the multiple exciton generation (MEG of QDs, 3 fabrication methods of QDs, and 4 nanocrystalline photoelectrodes for solar cells. We also make suggestions for future research on QDSCs. Although the efficiency of QDSCs is still low, we think there will be major breakthroughs in developing QDSCs in the future.

  4. Recent Advances in Organic Solar Cells

    Directory of Open Access Journals (Sweden)

    Thomas Kietzke

    2007-01-01

    Full Text Available Solar cells based on organic semiconductors have attracted much attention. The thickness of the active layer of organic solar cells is typically only 100 nm thin, which is about 1000 times thinner than for crystalline silicon solar cells and still 10 times thinner than for current inorganic thin film cells. The low material consumption per area and the easy processing of organic semiconductors offer a huge potential for low cost large area solar cells. However, to compete with inorganic solar cells the efficiency of organic solar cells has to be improved by a factor of 2-3. Several organic semiconducting materials have been investigated so far, but the optimum material still has to be designed. Similar as for organic light emitting devices (OLED small molecules are competing with polymers to become the material of choice. After a general introduction into the device structures and operational principles of organic solar cells the three different basic types (all polymer based, all small molecules based and small molecules mixed with polymers are described in detail in this review. For each kind the current state of research is described and the best of class reported efficiencies are listed.

  5. Industrial n-type solar cells with >20% cell efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Romijn, I.G.; Anker, J.; Burgers, A.R.; Gutjahr, A.; Koppes, M.; Kossen, E.J.; Lamers, M.W.P.E.; Heurtault, Benoit; Saynova-Oosterling, D.S.; Tool, C.J.J. [ECN Solar Energy, Petten (Netherlands)

    2013-03-15

    To realize high efficiencies at low costs, ECN has developed the n-Pasha solar cell concept. The n-Pasha cell concept is a bifacial solar cell concept on n-Cz base material, with which average efficiencies of above 20% have been demonstrated. In this paper recent developments at ECN to improve the cost of ownership (lower Euro/Wp) of the n-Pasha cell concept are discussed. Two main drivers for the manufacturing costs of n-type solar cells are addressed: the n-type Cz silicon material and the silver consumption. We show that a large resistivity range between 2 and 8 cm can be tolerated for high cell efficiency, and that the costs due to the silver metallization can be significantly reduced while increasing the solar cell efficiency. Combining the improved efficiency and cost reduction makes the n-Pasha cell concept a very cost effective solution to manufacture high efficient solar cells and modules.

  6. Chemically Deposited Thin-Film Solar Cell Materials

    Science.gov (United States)

    Raffaelle, R.; Junek, W.; Gorse, J.; Thompson, T.; Harris, J.; Hehemann, D.; Hepp, A.; Rybicki, G.

    2005-01-01

    We have been working on the development of thin film photovoltaic solar cell materials that can be produced entirely by wet chemical methods on low-cost flexible substrates. P-type copper indium diselenide (CIS) absorber layers have been deposited via electrochemical deposition. Similar techniques have also allowed us to incorporate both Ga and S into the CIS structure, in order to increase its optical bandgap. The ability to deposit similar absorber layers with a variety of bandgaps is essential to our efforts to develop a multi-junction thin-film solar cell. Chemical bath deposition methods were used to deposit a cadmium sulfide (CdS) buffer layers on our CIS-based absorber layers. Window contacts were made to these CdS/CIS junctions by the electrodeposition of zinc oxide (ZnO). Structural and elemental determinations of the individual ZnO, CdS and CIS-based films via transmission spectroscopy, x-ray diffraction, x-ray photoelectron spectroscopy and energy dispersive spectroscopy will be presented. The electrical characterization of the resulting devices will be discussed.

  7. Organic Tandem Solar Cells: Design and Formation

    Science.gov (United States)

    Chen, Chun-Chao

    In the past decade, research on organic solar cells has gone through an important development stage leading to major enhancements in power conversion efficiency, from 4% to 9% in single-junction devices. During this period, there are many novel processing techniques and device designs that have been proposed and adapted in organic solar-cell devices. One well-known device architecture that helps maximize the solar cell efficiency is the multi-junction tandem solar-cell design. Given this design, multiple photoactive absorbers as subcells are stacked in a monolithic fashion and assembled via series connection into one complete device, known as the tandem solar cell. Since multiple absorbers with different optical energy bandgaps are being applied in one tandem solar-cell device, the corresponding solar cell efficiency is maximized through expanded absorption spectrum and reduced carrier thermalization loss. In Chapter 3, the architecture of solution-processible, visibly transparent solar cells is introduced. Unlike conventional organic solar-cell devices with opaque electrodes (such as silver, aluminum, gold and etc.), the semi-transparent solar cells rely on highly transparent electrodes and visibly transparent photoactive absorbers. Given these two criteria, we first demonstrated the visibly transparent single-junction solar cells via the polymer absorber with near-infrared absorption and the top electrode based on solution-processible silver nanowire conductor. The highest visible transparency (400 ˜ 700 nm) of 65% was achieved for the complete device structure. More importantly, power conversion efficiency of 4% was also demonstrated. In Chapter 4, we stacked two semi-transparent photoactive absorbers in the tandem architecture in order to realize the semi-transparent tandem solar cells. A noticeable performance improvement from 4% to 7% was observed. More importantly, we modified the interconnecting layers with the incorporation of a thin conjugated

  8. Solar cell with silicon oxynitride dielectric layer

    Science.gov (United States)

    Shepherd, Michael; Smith, David D

    2015-04-28

    Solar cells with silicon oxynitride dielectric layers and methods of forming silicon oxynitride dielectric layers for solar cell fabrication are described. For example, an emitter region of a solar cell includes a portion of a substrate having a back surface opposite a light receiving surface. A silicon oxynitride (SiO.sub.xN.sub.y, 0

  9. Scaling Up ITO-free solar cells

    DEFF Research Database (Denmark)

    Galagan, Yulia; Coenen, Erica W. C.; Zimmermann, Birger

    2014-01-01

    resistances. The performance of ITO-free organic solar cells with different dimensions and different electrode resistances are evaluated for different light intensities. The current generation and electric potential distribution are found to not be uniformly distributed in large-area devices at simulated 1......Indium-tin-oxide-free (ITO-free) polymer solar cells with composite electrodes containing current-collecting grids and a semitransparent poly(3,4-ethylenedioxythiophene):polystyrenesulfonate) (PEDOT:PSS) conductor are demonstrated. The up-scaling of the length of the solar cell from 1 to 6 cm...... Sun illumination. The generated current uniformity increases with decreasing light intensities....

  10. Solar Cell Production using UMG Silicon

    Energy Technology Data Exchange (ETDEWEB)

    Hovel, Harold; Prettyman, Kevin

    2009-09-21

    Materials studies and solar cells made from various blends of UMG Si are compared with reference solar (PV) grade in terms of efficiencies, voltages, currents, diffusion lengths, minority carrier lifetimes and compositions. The UMG material used in this study performed unexpectedly well when used in cells manufactured both in a lab environment and on a commercial PV line. The limited number of cells of each composition does not support a full statistical analysis. However in comparing solar efficiencies, it is clear that a relatively minor delta exists between UMG blends and the particular PV grade material used in this study. That delta is between zero and 0.5 percentage points.

  11. A FETISH for gallium arsenide

    Energy Technology Data Exchange (ETDEWEB)

    Barron, A.R. [Rice Univ., Houston, TX (United States)

    1996-12-31

    An overview of the development of a new dielectric material, cubic-GaS, from the synthesis of new organometallic compounds to the fabrication of a new class of gallium arsenide based transistor is presented as a representative example of the possibility that inorganic chemistry can directly effect the development of new semiconductor devices. The gallium sulfido compound [({sup t}Bu)GaS]{sub 4}, readily prepared from tri-tert-butyl gallium, may be used as a precursor for the growth of GaS thin films by metal organic chemical vapor deposition (MOCVD). Photoluminescence and electronic measurements indicate that this material provides a passivation coating for GaAs. Furthermore, the insulating properties of cubic-GaS make it suitable as the insulating gate layer in a new class of GaAs transistor: a field effect transistor with a sulfide heterojunction (FETISH).

  12. Cadmium-induced malignant transformation in rat liver cells: role of aberrant oncogene expression and minimal role of oxidative stress.

    Science.gov (United States)

    Qu, Wei; Diwan, Bhalchandra A; Reece, Jeffrey M; Bortner, Carl D; Pi, Jingbo; Liu, Jie; Waalkes, Michael P

    2005-04-10

    Our study examined the role of oxidative stress and aberrant gene expression in malignant transformation induced by chronic, low-level cadmium exposure in non-tumorigenic rat liver epithelial cell line, TRL 1215. Cells were cultured in 1.0 microM cadmium (as CdCl(2)) for up to 28 weeks and compared to passage-matched control cells. The level of cadmium used for transformation produced no evidence of increased superoxide (O(2) (-*.)) or hydrogen peroxide (H(2)O(2)) levels in the early stages of exposure (hr). The chronic cadmium exposed liver epithelial cells (CCE-LE) were hyperproliferative with a growth rate about 3-fold higher than control cells. CCE-LE cells produced highly aggressive tumors upon inoculation into mice confirming malignant transformation. Analysis of cellular reactive oxygen species (ROS) showed that CCE-LE cells possessed markedly lower basal levels of intracellular O(2) (-*.)and H(2)O(2) and were very tolerant to high-dose (50 microM) cadmium-induced ROS. Time course studies showed the production of ROS by high-dose cadmium was abolished well in advance of malignant transformation. In contrast, marked overexpression of the oncogenes c-myc and c-jun occurred in transformed CCE-LE cells as evidenced by up to 10-fold increases in both transcript and protein. A significant increase in DNA-binding activity of the transcription factors AP-1 and NF-kappaB occurred in CCE-LE cells. Increases in oncogene expression and transcription factor activity occurred concurrently with malignant transformation. Thus, cadmium-induced ROS occurs as an early, high-dose event but is abolished well in advance of malignant transformation. Low-level chronic cadmium triggers oncogene overexpression possibly by altering critical transcription factor activity. Such changes in cellular gene expression likely culminate in the loss of growth control and cadmium-induced neoplastic transformation in CCE-LE cells, whereas generation of ROS by cadmium seemed to play a minimal role

  13. Recent Advances in Dye Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Umer Mehmood

    2014-01-01

    Full Text Available Solar energy is an abundant and accessible source of renewable energy available on earth, and many types of photovoltaic (PV devices like organic, inorganic, and hybrid cells have been developed to harness the energy. PV cells directly convert solar radiation into electricity without affecting the environment. Although silicon based solar cells (inorganic cells are widely used because of their high efficiency, they are rigid and manufacturing costs are high. Researchers have focused on organic solar cells to overcome these disadvantages. DSSCs comprise a sensitized semiconductor (photoelectrode and a catalytic electrode (counter electrode with an electrolyte sandwiched between them and their efficiency depends on many factors. The maximum electrical conversion efficiency of DSSCs attained so far is 11.1%, which is still low for commercial applications. This review examines the working principle, factors affecting the efficiency, and key challenges facing DSSCs.

  14. Optical models for silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, T.; Sopori, B. [National Renewable Energy Lab., Golden, CO (United States)

    1995-08-01

    Light trapping is an important design feature for high-efficiency silicon solar cells. Because light trapping can considerably enhance optical absorption, a thinner substrate can be used which, in turn, can lower the bulk carrier recombination and concommitantly increase open-circuit voltage, and fill factor of the cell. The basic concepts of light trapping are similar to that of excitation of an optical waveguide, where a prism or a grating structure increases the phase velocity of the incoming optical wave such that waves propagated within the waveguide are totally reflected at the interfaces. Unfortunately, these concepts break down because the entire solar cell is covered with such a structure, making it necessary to develop new analytical approaches to deal with incomplete light trapping in solar cells. This paper describes two models that analyze light trapping in thick and thin solar cells.

  15. Development and Prospect of Nanoarchitectured Solar Cells

    Directory of Open Access Journals (Sweden)

    Bo Zhang

    2015-01-01

    Full Text Available This paper gives an overview of the development and prospect of nanotechnologies utilized in the solar cell applications. Even though it is not clearly pointed out, nanostructures indeed have been used in the fabrication of conventional solar cells for a long time. However, in those circumstances, only very limited benefits of nanostructures have been used to improve cell performance. During the last decade, the development of the photovoltaic device theory and nanofabrication technology enables studies of more complex nanostructured solar cells with higher conversion efficiency and lower production cost. The fundamental principles and important features of these advanced solar cell designs are systematically reviewed and summarized in this paper, with a focus on the function and role of nanostructures and the key factors affecting device performance. Among various nanostructures, special attention is given to those relying on quantum effect.

  16. Effect of cadmium on the nucleoli of meristematic cells of onion Allium cepa L: an ultrastructural study.

    Science.gov (United States)

    Marcano, L; Carruyo, I; Del Campo, A; Montiel, X

    2002-01-01

    This study of the effect of cadmium on nucleolar ultrastructure was carried out with meristematic cell populations of Allium cepa L. Meristems, grown at 25 degrees C, were treated with 10 ppm cadmium chloride. Conventional and silver staining techniques were carried out, and the ultrastructure was analyzed using electron microscopy. Observation showed alterations in the nucleoli of the cells that had been treated with cadmium and this effect varied according to the time of exposure to the metal. After 4h of treatment, nucleolar segregation was observed in interphase, probably because of the effect of cadmium on the synthesis of ribosomal RNA precursors. A decrease in the fibrillar to granular component ratio also occurred in the cells exposed to Cd2+ for 8 h. Some changes were observed in the G1 cells; their chromatin still remained very condensed, and prenucleolus bodies remained scattered within the nucleus. At the same time, there was a large amount of interchromatin granules. These changes produced by cadmium resembled those produced during inhibition of RNA synthesis. The fibrillar bodies, another morphologic feature, resulting from a blocked transcription, were also evidenced. All these observations suggest that one of the ways that cadmium exercises its toxicity is by altering the biosynthesis of the preribosomal RNA precursor.

  17. Indium oxide/n-silicon heterojunction solar cells

    Science.gov (United States)

    Feng, Tom; Ghosh, Amal K.

    1982-12-28

    A high photo-conversion efficiency indium oxide/n-silicon heterojunction solar cell is spray deposited from a solution containing indium trichloride. The solar cell exhibits an Air Mass One solar conversion efficiency in excess of about 10%.

  18. Computer simulation of amorphous MIS solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Shousha, A.H.M.; El-Kosheiry, M.A. [Cairo University (Egypt). Electronics and Communications Engineering Dept.

    1997-10-01

    A computer model to simulate amorphous MIS solar cells is developed. The model is based on the self-consistent solution of the electron and hole continuity equations, together with the Poisson equation under proper boundary conditions. The program developed is used to investigate the cell performance characteristics in terms of its physical and structural parameters. The current-voltage characteristics of the solar cell are obtained under AMI solar illumination. The dependences of the short-circuit current, open-circuit voltage, fill factor and cell conversion efficiency on localized gap state density, carrier lifetime, cell thickness and surface recombination velocity are obtained and discussed. The results presented show how cell parameters can be varied to improve the cell performance characteristics. (Author)

  19. Solar cell anomaly detection method and apparatus

    Science.gov (United States)

    Miller, Emmett L. (Inventor); Shumka, Alex (Inventor); Gauthier, Michael K. (Inventor)

    1981-01-01

    A method is provided for detecting cracks and other imperfections in a solar cell, which includes scanning a narrow light beam back and forth across the cell in a raster pattern, while monitoring the electrical output of the cell to find locations where the electrical output varies significantly. The electrical output can be monitored on a television type screen containing a raster pattern with each point on the screen corresponding to a point on the solar cell surface, and with the brightness of each point on the screen corresponding to the electrical output from the cell which was produced when the light beam was at the corresponding point on the cell. The technique can be utilized to scan a large array of interconnected solar cells, to determine which ones are defective.

  20. Solar cell array design handbook, volume 1

    Science.gov (United States)

    Rauschenbach, H. S.

    1976-01-01

    Twelve chapters discuss the following: historical developments, the environment and its effects, solar cells, solar cell filters and covers, solar cell and other electrical interconnections, blocking and shunt diodes, substrates and deployment mechanisms, material properties, design synthesis and optimization, design analysis, procurement, production and cost aspects, evaluation and test, orbital performance, and illustrative design examples. A comprehensive index permits rapid locating of desired topics. The handbook consists of two volumes: Volume 1 is of an expository nature while Volume 2 contains detailed design data in an appendix-like fashion. Volume 2 includes solar cell performance data, applicable unit conversion factors and physical constants, and mechanical, electrical, thermal optical, magnetic, and outgassing material properties. Extensive references are provided.

  1. Multijunction Ultralight Solar Cells and Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — There is a continuing need within NASA for solar cells and arrays with very high specific power densities (1000-5000 kW/kg) for generating power in a new generation...

  2. Black Silicon Solar Cells with Black Ribbons

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Tang, Peter Torben; Mizushima, Io

    2016-01-01

    We present the combination of mask-less reactive ion etch (RIE) texturing and blackened interconnecting ribbons as a method for obtaining all-black solar panels, while using conventional, front-contacted solar cells. Black silicon made by mask-less reactive ion etching has total, average...... in the range 15.7-16.3%. The KOH-textured reference cell had an efficiency of 17.9%. The combination of black Si and black interconnecting ribbons may result in aesthetic, all-black panels based on conventional, front-contacted silicon solar cells....... reflectance below 0.5% across a 156x156 mm2 silicon (Si) wafer. Black interconnecting ribbons were realized by oxidizing copper resulting in reflectance below 3% in the visible wavelength range. Screen-printed Si solar cells were realized on 156x156 mm2 black Si substrates with resulting efficiencies...

  3. High Efficiency, Deployable Solar Cells Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Ultrathin, lightweight, flexible, and easily deployable solar cell (SC) capable of specific power greater than 1kW/kg are at an early stage of development for...

  4. Solar cell efficiency tables (version 50)

    Energy Technology Data Exchange (ETDEWEB)

    Green, Martin A. [Australian Centre for Advanced Photovoltaics, University of New South Wales, Sydney 2052 Australia; Hishikawa, Yoshihiro [National Institute of Advanced Industrial Science and Technology (AIST), Research Center for Photovoltaics (RCPV), Central 2, Umezono 1-1-1, Ibaraki Tsukuba 305-8568 Japan; Warta, Wilhelm [Department: Characterisation and Simulation/CalLab Cells, Fraunhofer-Institute for Solar Energy Systems, Heidenhofstr. 2 Freiburg D-79110 Germany; Dunlop, Ewan D. [European Commission-Joint Research Centre, Directorate C-Energy, Transport and Climate, Via E. Fermi 2749 Ispra IT-21027 VA Italy; Levi, Dean H. [National Renewable Energy Laboratory, 15013 Denver West Parkway Golden CO 80401 USA; Hohl-Ebinger, Jochen [Department: Characterisation and Simulation/CalLab Cells, Fraunhofer-Institute for Solar Energy Systems, Heidenhofstr. 2 Freiburg D-79110 Germany; Ho-Baillie, Anita W. H. [Australian Centre for Advanced Photovoltaics, University of New South Wales, Sydney 2052 Australia

    2017-06-21

    Consolidated tables showing an extensive listing of the highest independently confirmed efficiencies for solar cells and modules are presented. Guidelines for inclusion of results into these tables are outlined, and new entries since January 2017 are reviewed.

  5. Low-Dose Cadmium Upregulates VEGF Expression in Lung Adenocarcinoma Cells

    Directory of Open Access Journals (Sweden)

    Fuhong Liu

    2015-08-01

    Full Text Available Cadmium (Cd is a heavy metal and environmental toxin. Exposure to Cd has been associated with a variety of human cancers. In this study, we performed in vitro assays to examine the effects of cadmium chloride (CdCl2 on A549 cells, a human lung adenocarcinoma cell line. Cd does not affect proliferation, migration, or apoptosis of A549 cells at concentrations of 0.1–10 μM. At 0.5 and 1 μM, Cd increases the expression of vascular endothelial growth factor (VEGF (p < 0.05, p < 0.01, respectively, but not basic fibroblast growth factor (b-FGF in A549 cells. The conditioned media were collected from the A549 cells treated with 1 μM Cd and were co-cultured with human umbilical vein endothelial cells (HUVECs. Upon treatment with the conditioned media, the proliferation and migration of HUVECs significantly increased (p < 0.01, p < 0.05, respectively, while apoptosis remained unchanged. In addition, 1 μM Cd increases the level of hypoxia inducible factor 1-α (HIF1-α, which is a positive regulator of VEGF expression. Although low-dose Cd does not directly affect the growth of lung adenocarcinoma cells, it might facilitate the development of tumors through its pro-angiogenic effects.

  6. Singlet fission: Towards efficient solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Havlas, Zdeněk; Wen, Jin [Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 16610 Prague 6 (Czech Republic); Michl, Josef [Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215 (United States); Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 16610 Prague 6 (Czech Republic)

    2015-12-31

    Singlet fission (SF) offers an opportunity to improve solar cell efficiency, but its practical use is hindered by the limited number of known efficient materials, limited knowledge of SF mechanism, mainly the relation between the dimer structure and SF efficiency and diffusion of the triplet states allowing injection of electrons into the solar cell semiconductor band. Here we report on our attempt to design new classes of chromophores and to study the relation between the structure and SF efficiency.

  7. Investigating dye-sensitised solar cells

    Science.gov (United States)

    Tobin, Laura L.; O'Reilly, Thomas; Zerulla, Dominic; Sheridan, John T.

    2010-05-01

    At present there is considerable global concern in relation to environmental issues and future energy supplies, for instance climate change (global warming) and the rapid depletion of fossil fuel resources. This trepidation has initiated a more critical investigation into alternative and renewable sources of power such as geothermal, biomass, hydropower, wind and solar energy. The immense dependence on electrical power in today's society has prompted the manufacturing of devices such as photovoltaic (PV) cells to help alleviate and replace current electrical demands of the power grid. The most popular and commercially available PV cells are silicon solar cells which have to date the greatest efficiencies for PV cells. The drawback however is that the manufacturing of these cells is complex and costly due to the expense and difficulty of producing and processing pure silicon. One relatively inexpensive alternative to silicon PV cells that we are currently studying are dye-sensitised solar cells (DSSC or Grätzel Cells). DSSC are biomimetic solar cells which are based on the process of photosynthesis. The SFI Strategic Research Centre for Solar Energy Conversion is a research cluster based in Ireland formed with the express intention of bringing together industry and academia to produce renewable energy solutions. Our specific research area is in DSSC and their electrical properties. We are currently developing testing equipment for arrays of DSSC and developing optoelectronic models which todescribe the performance and behaviour of DSSCs.

  8. Gene expression and pathway analysis of human hepatocellular carcinoma cells treated with cadmium.

    Science.gov (United States)

    Cartularo, Laura; Laulicht, Freda; Sun, Hong; Kluz, Thomas; Freedman, Jonathan H; Costa, Max

    2015-11-01

    Cadmium (Cd) is a toxic and carcinogenic metal naturally occurring in the Earth's crust. A common route of human exposure is via diet and cadmium accumulates in the liver. The effects of Cd exposure on gene expression in human hepatocellular carcinoma (HepG2) cells were examined in this study. HepG2 cells were acutely-treated with 0.1, 0.5, or 1.0 μM Cd for 24h; or chronically-treated with 0.01, 0.05, or 0.1 μM Cd for three weeks and gene expression analysis was performed using Affymetrix GeneChip® Human Gene 1.0 ST Arrays. Acute and chronic exposures significantly altered the expression of 333 and 181 genes, respectively. The genes most upregulated by acute exposure included several metallothioneins. Downregulated genes included the monooxygenase CYP3A7, involved in drug and lipid metabolism. In contrast, CYP3A7 was upregulated by chronic Cd exposure, as was DNAJB9, an anti-apoptotic J protein. Genes downregulated following chronic exposure included the transcriptional regulator early growth response protein 1. Ingenuity Pathway Analysis revealed that the top networks altered by acute exposure were lipid metabolism, small molecule biosynthesis, cell morphology, organization, and development; while top networks altered by chronic exposure were organ morphology, cell cycle, cell signaling, and renal and urological diseases/cancer. Many of the dysregulated genes play important roles in cellular growth, proliferation, and apoptosis, and may be involved in carcinogenesis. In addition to gene expression changes, HepG2 cells treated with cadmium for 24h indicated a reduction in global levels of histone methylation and acetylation that persisted 72 h post-treatment. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Harnessing Sun’s Energy with Quantum Dots Based Next Generation Solar Cell

    Science.gov (United States)

    Halim, Mohammad A.

    2012-01-01

    Our energy consumption relies heavily on the three components of fossil fuels (oil, natural gas and coal) and nearly 83% of our current energy is consumed from those sources. The use of fossil fuels, however, has been viewed as a major environmental threat because of their substantial contribution to greenhouse gases which are responsible for increasing the global average temperature. Last four decades, scientists have been searching for alternative sources of energy which need to be environmentally clean, efficient, cost-effective, renewable, and sustainable. One of the promising sustainable sources of energy can be achieved by harnessing sun energy through silicon wafer, organic polymer, inorganic dye, and quantum dots based solar cells. Among them, quantum dots have an exceptional property in that they can excite multiple electrons using only one photon. These dots can easily be synthesized, processed in solution, and incorporated into solar cell application. Interestingly, the quantum dots solar cells can exceed the Shockley-Queisser limit; however, it is a great challenge for other solar cell materials to exceed the limit. Theoretically, the quantum dots solar cell can boost the power conversion efficiency up to 66% and even higher to 80%. Moreover, in changing the size of the quantum dots one can utilize the Sun’s broad spectrum of visible and infrared ranges. This review briefly overviews the present performance of different materials-based solar cells including silicon wafer, dye-sensitized, and organic solar cells. In addition, recent advances of the quantum dots based solar cells which utilize cadmium sulfide/selenide, lead sulfide/selenide, and new carbon dots as light harvesting materials has been reviewed. A future outlook is sketched as to how one could improve the efficiency up to 10% from the current highest efficiency of 6.6%. PMID:28348320

  10. Harnessing Sun's Energy with Quantum Dots Based Next Generation Solar Cell.

    Science.gov (United States)

    Halim, Mohammad A

    2012-12-27

    Our energy consumption relies heavily on the three components of fossil fuels (oil, natural gas and coal) and nearly 83% of our current energy is consumed from those sources. The use of fossil fuels, however, has been viewed as a major environmental threat because of their substantial contribution to greenhouse gases which are responsible for increasing the global average temperature. Last four decades, scientists have been searching for alternative sources of energy which need to be environmentally clean, efficient, cost-effective, renewable, and sustainable. One of the promising sustainable sources of energy can be achieved by harnessing sun energy through silicon wafer, organic polymer, inorganic dye, and quantum dots based solar cells. Among them, quantum dots have an exceptional property in that they can excite multiple electrons using only one photon. These dots can easily be synthesized, processed in solution, and incorporated into solar cell application. Interestingly, the quantum dots solar cells can exceed the Shockley-Queisser limit; however, it is a great challenge for other solar cell materials to exceed the limit. Theoretically, the quantum dots solar cell can boost the power conversion efficiency up to 66% and even higher to 80%. Moreover, in changing the size of the quantum dots one can utilize the Sun's broad spectrum of visible and infrared ranges. This review briefly overviews the present performance of different materials-based solar cells including silicon wafer, dye-sensitized, and organic solar cells. In addition, recent advances of the quantum dots based solar cells which utilize cadmium sulfide/selenide, lead sulfide/selenide, and new carbon dots as light harvesting materials has been reviewed. A future outlook is sketched as to how one could improve the efficiency up to 10% from the current highest efficiency of 6.6%.

  11. Harnessing Sun’s Energy with Quantum Dots Based Next Generation Solar Cell

    Directory of Open Access Journals (Sweden)

    Mohammad A. Halim

    2012-12-01

    Full Text Available Our energy consumption relies heavily on the three components of fossil fuels (oil, natural gas and coal and nearly 83% of our current energy is consumed from those sources. The use of fossil fuels, however, has been viewed as a major environmental threat because of their substantial contribution to greenhouse gases which are responsible for increasing the global average temperature. Last four decades, scientists have been searching for alternative sources of energy which need to be environmentally clean, efficient, cost-effective, renewable, and sustainable. One of the promising sustainable sources of energy can be achieved by harnessing sun energy through silicon wafer, organic polymer, inorganic dye, and quantum dots based solar cells. Among them, quantum dots have an exceptional property in that they can excite multiple electrons using only one photon. These dots can easily be synthesized, processed in solution, and incorporated into solar cell application. Interestingly, the quantum dots solar cells can exceed the Shockley-Queisser limit; however, it is a great challenge for other solar cell materials to exceed the limit. Theoretically, the quantum dots solar cell can boost the power conversion efficiency up to 66% and even higher to 80%. Moreover, in changing the size of the quantum dots one can utilize the Sun’s broad spectrum of visible and infrared ranges. This review briefly overviews the present performance of different materials-based solar cells including silicon wafer, dye-sensitized, and organic solar cells. In addition, recent advances of the quantum dots based solar cells which utilize cadmium sulfide/selenide, lead sulfide/selenide, and new carbon dots as light harvesting materials has been reviewed. A future outlook is sketched as to how one could improve the efficiency up to 10% from the current highest efficiency of 6.6%.

  12. Cell-surface changes in cadmium-resistant Euglena: Studies using lectin-binding techniques and flow cytometry

    Energy Technology Data Exchange (ETDEWEB)

    Bonaly, J.; Brochiero, E. [Faculte de Pharmacie, Chatenay-Malabry (France)

    1994-01-01

    Most in vitro studies on contaminants focus on the short-term effects of pollutants on cells, without regard to long-term effects and the ability of cells or microorganisms to develop a specific resistance to a pollutant. Cadmium is ubiquitous environmental contaminant. This heavy metal enters the aquatic environment mainly through vapor emissions and fallout during smelting operations. Diverse mechanisms of algal resistance to toxic metals are known. Among these, the most general mechanism is the development of metal-binding proteins. In cadmium-resistant unicellular Euglena gracilis Z algae cells, the metal did not appear to be sequestered on soluble metal-binding ligands. Previous experiments have shown that resistance development is related to a diminution of cadmium penetration into cells, implicating cell surface or membrane alteration. This research investigates the mechanisms of development of cadmium resistance in Euglena cells at the cell-surface level. Sugar chains of glycoproteins and glycolipids are a predominant feature of the surface of cells. Moreover, the cell-response to environmental changes is often orchestrated through surface macromolecules such as glycoproteins. In this study, we applied this lectin method to investigate surface carbohydrate expression during and after resistance development. Our interest was twofold: (1) to learn more about the carbohydrate composition of the cell-surface of Euglena; and (2) to determine whether transition from wild cells to Cd-resistant cells changes the expression of cell-surface carbohydrates. 13 refs., 2 figs., 1 tab.

  13. Perovskite solar cells: from materials to devices.

    Science.gov (United States)

    Jung, Hyun Suk; Park, Nam-Gyu

    2015-01-07

    Perovskite solar cells based on organometal halide light absorbers have been considered a promising photovoltaic technology due to their superb power conversion efficiency (PCE) along with very low material costs. Since the first report on a long-term durable solid-state perovskite solar cell with a PCE of 9.7% in 2012, a PCE as high as 19.3% was demonstrated in 2014, and a certified PCE of 17.9% was shown in 2014. Such a high photovoltaic performance is attributed to optically high absorption characteristics and balanced charge transport properties with long diffusion lengths. Nevertheless, there are lots of puzzles to unravel the basis for such high photovoltaic performances. The working principle of perovskite solar cells has not been well established by far, which is the most important thing for understanding perovksite solar cells. In this review, basic fundamentals of perovskite materials including opto-electronic and dielectric properties are described to give a better understanding and insight into high-performing perovskite solar cells. In addition, various fabrication techniques and device structures are described toward the further improvement of perovskite solar cells. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Perovskite Solar Cells: Progress and Advancements

    Directory of Open Access Journals (Sweden)

    Naveen Kumar Elumalai

    2016-10-01

    Full Text Available Organic–inorganic hybrid perovskite solar cells (PSCs have emerged as a new class of optoelectronic semiconductors that revolutionized the photovoltaic research in the recent years. The perovskite solar cells present numerous advantages include unique electronic structure, bandgap tunability, superior charge transport properties, facile processing, and low cost. Perovskite solar cells have demonstrated unprecedented progress in efficiency and its architecture evolved over the period of the last 5–6 years, achieving a high power conversion efficiency of about 22% in 2016, serving as a promising candidate with the potential to replace the existing commercial PV technologies. This review discusses the progress of perovskite solar cells focusing on aspects such as superior electronic properties and unique features of halide perovskite materials compared to that of conventional light absorbing semiconductors. The review also presents a brief overview of device architectures, fabrication methods, and interface engineering of perovskite solar cells. The last part of the review elaborates on the major challenges such as hysteresis and stability issues in perovskite solar cells that serve as a bottleneck for successful commercialization of this promising PV technology.

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

    OpenAIRE

    Skhouni, Othmane; EL MANOUNI, AHMED; Marí, B.; Ullah, Hanif

    2016-01-01

    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 bee...

  16. Effects of exposure to cadmium in sperm cells of zebrafish, Danio rerio

    Directory of Open Access Journals (Sweden)

    Izani Bonel Acosta

    2016-01-01

    Full Text Available Cadmium is a natural element found in the earth’s crust; it is usually associated with other metals, but due to the impacts caused by human activity, its concentration has increased in the aquatic environment. This metal may damage aquatic animal reproduction, decreasing the rate of fertilization of organisms such as fish. Thus, this study aimed to evaluate the in vitro toxicity of different concentrations of cadmium (0 (control, 0.5, 5, and 10 μg/L using sperm cells of model organism zebrafish, Danio rerio. Structural parameters, including integrity and fluidity of the plasma membrane, concentration of oxygen species, mitochondrial function and DNA fragmentation were measured by flow cytometry. The following sperm movement parameters were also measured using the computer assisted sperm analysis (CASA system: motility, time of motility, curvilinear velocity, average path velocity and straight line velocity in μm/s. Significant effects were observed on path speed, straight speed, curvilinear velocity, motility time, progressive and total motility, and plasma and DNA integrity. The results showed that cadmium can negatively affect some reproductive parameters in D. rerio, which may reduce the fertility rate of these animals.

  17. Effect of cadmium chloride on the distal retinal pigment cells of the fiddler crab, Uca pugilator

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, P.S.; Fingerman, M. [Tulane Univ., New Orleans, LA (United States); Nguyen, L.K.; Obih, P. [Xavier Univ., New Orleans, LA (United States)

    1997-03-01

    Crustaceans have two sets of pigmentary effectors, chromatophores and retinal pigment cells. Retinal pigments control the amount of light striking the rhabdom, the photosensitive portion of each ommatidium, screening the rhabdom in bright light and uncovering it in darkness or dim light. Migration of the distal pigment in the fiddler crab, Uca pugilalor, is regulated by a light-adapting hormone and a dark-adapting hormone. The black chromatophores of this crab are also controlled by a pair of hormones. Both pigmentary effectors exhibit circadian rhythms. The effects of some organic and inorganic pollutants on the ability of Uca pugilator to change color have been described. Exposure of this crab to naphthalene or cadmium results in decreased ability to disperse the pigment in their black chromatophores, the exposed crabs becoming paler than the unexposed crabs. Norepinephrine triggers release of both the black pigment-dispersing hormone and the light-adapting hormone. In view of the facts that (a) these hormones which regulate the black chromatophores and distal pigment are synthesized in and released from the eyestalk neuroendocrine complex, (b) the black pigment-dispersing hormone and the light-adapting hormone may actually be the same hormone. having two different activities and (c) release of both the black pigment-dispersing hormone and the light-adapting hormone is triggered by norepinephrine, the present investigation was carried out to determine the effect of cadmium on distal pigment migration in Uca pugilator. More specifically, for comparison with the previously reported effect of cadmium on pigment migration in the black chromatophores, we wished to determine whether the distal pigment of fiddler crabs exposed to cadmium chloride is capable of as wide a range of movement as in unexposed crabs, and if not what might be the explanation. This is the first report of the effect of a pollutant on a retinal pigment of any crustacean. 12 refs., 3 tabs.

  18. Bone marrow mesenchymal stem cells repair cadmium-induced rat testis injury by inhibiting mitochondrial apoptosis.

    Science.gov (United States)

    Wang, Yong-Jie; Yan, Jun; Zou, Xiao-Li; Guo, Ke-Jun; Zhao, Yue; Meng, Chun-Yang; Yin, Fei; Guo, Li

    2017-06-01

    Cadmium is a highly toxic metal with widespread exposure to people that can cause tissue injuries that lack effective treatment. The aim of this project was to uncover whether bone marrow mesenchymal stem cells (BMSCs) can repair cadmium-induced rat testis injury and to explore the role of mitochondrial apoptosis in this process. To this end, 21 adult male Wistar rats were randomly divided into control, model and therapy groups, 7 each, and were administered 0, 0.4 and 0.4 mg/kg body weight CdCl2 saline solution, respectively, by intraperitoneal injection 5 times per week for 5 weeks. Then, rats in the therapy group were treated with 10(7) BMSCs by retro-orbital injections, while the others were given equal volumes of phosphate buffered saline. Following 2-week BMSCs-treatment, the therapy rats were heavier than the model rats, despite there being no difference in testicular cadmium contents between these groups, which were both significantly higher than the control group. BMSCs were observed in the testis of the therapy rats, in which pathological changes improved significantly compared with the model group. Expression of the apoptosis-associated proteins Bim, Bax, Cytochrome C, Caspase-3, active-Caspase-3 and AIF increased, while Bcl-2 was reduced significantly in rat testes of model group compared with the other groups. Based on these findings, we conclude that cadmium can accumulate in rat testes where it caused severe tissue injury, BMSCs can be localized to the injured testicular tissue of rats and repair the tissue injury, these reparative effects may be highly related with mitochondrial apoptosis. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Effect of Cadmium on Macrophage U937 Cell Proliferation and ...

    African Journals Online (AJOL)

    BSN

    chloride (CdCl2) obtained from Merck. (Germany), cell line U937 was obtained from the. European collection of cell cultures (Salisbury,. UK). Fetal calf serum, phorbol 12-myristate 13- acetate, L-glutamate, streptomycin, extravidin- horse raddish peroxidase conjugate (extravidin-. HRP) and trypan blue were purchased from.

  20. Experimental advances in the next generation of solar cells

    OpenAIRE

    Martí Vega, Antonio; Luque López, Antonio

    2010-01-01

    We consider next generation solar cells concepts those that have the potential to exceed the limiting efficiency calculated by Shockley and Queisser for single gap solar cells (40.7 %) and still have not been commercialized. Among these concepts, this paper deals with the multiple exciton generation (or impact ionization or multiple carrier generation) solar cell, the intermediate band solar cell and the hot carrier solar cell. These concepts were proposed theoretically more than ten yea...

  1. Cadmium induces carcinogenesis in BEAS-2B cells through ROS-dependent activation of PI3K/AKT/GSK-3β/β-catenin signaling

    Energy Technology Data Exchange (ETDEWEB)

    Son, Young-Ok; Wang, Lei; Poyil, Pratheeshkumar; Budhraja, Amit; Hitron, J. Andrew; Zhang, Zhuo [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY (United States); Lee, Jeong-Chae [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY (United States); School of Dentistry and Institute of Oral Biosciences (BK21 program), Research Center of Bioactive Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Shi, Xianglin, E-mail: xshi5@email.uky.edu [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY (United States)

    2012-10-15

    Cadmium has been widely used in industry and is known to be carcinogenic to humans. Although it is widely accepted that chronic exposure to cadmium increases the incidence of cancer, the mechanisms underlying cadmium-induced carcinogenesis are unclear. The main aim of this study was to investigate the role of reactive oxygen species (ROS) in cadmium-induced carcinogenesis and the signal transduction pathways involved. Chronic exposure of human bronchial epithelial BEAS-2B cells to cadmium induced cell transformation, as evidenced by anchorage-independent growth in soft agar and clonogenic assays. Chronic cadmium treatment also increased the potential of these cells to invade and migrate. Injection of cadmium-stimulated cells into nude mice resulted in the formation of tumors. In contrast, the cadmium-mediated increases in colony formation, cell invasion and migration were prevented by transfection with catalase, superoxide dismutase-1 (SOD1), or SOD2. In particular, chronic cadmium exposure led to activation of signaling cascades involving PI3K, AKT, GSK-3β, and β-catenin and transfection with each of the above antioxidant enzymes markedly inhibited cadmium-mediated activation of these signaling proteins. Inhibitors specific for AKT or β-catenin almost completely suppressed the cadmium-mediated increase in total and active β-catenin proteins and colony formation. Moreover, there was a marked induction of AKT, GSK-3β, β-catenin, and carcinogenic markers in tumor tissues formed in mice after injection with cadmium-stimulated cells. Collectively, our findings suggest a direct involvement of ROS in cadmium-induced carcinogenesis and implicate a role of AKT/GSK-3β/β-catenin signaling in this process. -- Highlights: ► Chronic exposure to cadmium induces carcinogenic properties in BEAS-2B cells. ► ROS involved in cadmium-induced tumorigenicity of BEAS-2B cells. ► Cadmium activates ROS-dependent AKT/GSK-3β/β-catenin-mediated signaling. ► ROS

  2. HYBRID FUEL CELL-SOLAR CELL SPACE POWER SUBSYSTEM CAPABILITY.

    Science.gov (United States)

    This report outlines the capabilities and limitations of a hybrid solar cell- fuel cell space power subsystem by comparing the proposed hybrid system...to conventional power subsystem devices. The comparisons are based on projected 1968 capability in the areas of primary and secondary battery, fuel ... cell , solar cell, and chemical dynamic power subsystems. The purpose of the investigation was to determine the relative merits of a hybrid power

  3. Metabolic Profiling in Association with Vascular Endothelial Cell Dysfunction Following Non-Toxic Cadmium Exposure

    Science.gov (United States)

    Li, Xiaofei; Nong, Qingjiao; Mao, Baoyu; Pan, Xue

    2017-01-01

    This study aimed to determine the metabolic profile of non-toxic cadmium (Cd)-induced dysfunctional endothelial cells using human umbilical vein endothelial cells (HUVECs). HUVECs (n = 6 per group) were treated with 0, 1, 5, or 10 μM cadmium chloride (CdCl2) for 48 h. Cell phenotypes, including nitric oxide (NO) production, the inflammatory response, and oxidative stress, were evaluated in Cd-exposed and control HUVECs. Cd-exposed and control HUVECs were analysed using gas chromatography time-of-flight/mass spectrometry. Compared to control HUVECs, Cd-exposed HUVECs were dysfunctional, exhibiting decreased NO production, a proinflammatory state, and non-significant oxidative stress. Further metabolic profiling revealed 24 significantly-altered metabolites in the dysfunctional endothelial cells. The significantly-altered metabolites were involved in the impaired tricarboxylic acid (TCA) cycle, activated pyruvate metabolism, up-regulated glucogenic amino acid metabolism, and increased pyrimidine metabolism. The current metabolic findings further suggest that the metabolic changes linked to TCA cycle dysfunction, glycosylation of the hexosamine biosynthesis pathway (HBP), and compensatory responses to genomic instability and energy deficiency may be generally associated with dysfunctional phenotypes, characterized by decreased NO production, a proinflammatory state, and non-significant oxidative stress, in endothelial cells following non-toxic Cd exposure. PMID:28872622

  4. Protective effect of boric acid on lead- and cadmium-induced genotoxicity in V79 cells.

    Science.gov (United States)

    Ustündağ, Aylin; Behm, Claudia; Föllmann, Wolfram; Duydu, Yalçin; Degen, Gisela H

    2014-06-01

    The toxic heavy metals cadmium (Cd) and lead (Pb) are important environmental pollutants which can cause serious damage to human health. As the metal ions (Cd(2+) and Pb(2+)) accumulate in the organism, there is special concern regarding chronic toxicity and damage to the genetic material. Metal-induced genotoxicity has been attributed to indirect mechanisms, such as induction of oxidative stress and interference with DNA repair. Boron is a naturally occurring element and considered to be an essential micronutrient, although the cellular activities of boron compounds remain largely unexplored. The present study has been conducted to evaluate potential protective effects of boric acid (BA) against genotoxicity induced by cadmium chloride (CdCl2) and lead chloride (PbCl2) in V79 cell cultures. Cytotoxicity assays (neutral red uptake and cell titer blue assay) served to determine suitable concentrations for subsequent genotoxicity assays. Chromosomal damage and DNA strand breaks were assessed by micronucleus tests and comet assays. Both PbCl2 and CdCl2 (at 3, 5 and 10 µM) were shown to induce concentration-dependent increases in micronucleus frequencies and DNA strand breaks in V79 cells. BA itself was not cytotoxic (up to 300 µM) and showed no genotoxic effects. Pretreatment of cells with low levels of BA (2.5 and 10 µM) was found to strongly reduce the genotoxic effects of the tested metals. Based on the findings of this in vitro study, it can be suggested that boron provides an efficient protection against the induction of DNA strand breaks and micronuclei by lead and cadmium. Further studies on the underlying mechanisms for the protective effect of boron are needed.

  5. Qualitative and quantitative evaluation of thin-film solar cells using solar cell local characterization

    Science.gov (United States)

    Wagner, J.-M.; Carstensen, J.; Schütt, A.; Föll, H.

    2013-02-01

    The light-beam-induced current-based CELLO measurement technique (solar CELl LOcal characterization), originally developed for wafer-based silicon solar cells, can successfully be applied to thin-film solar cells, provided that contacting of a single cell is possible. This is shown exemplarily for several crystalline silicon on glass samples, having varying quality with respect to photocurrent extraction, series resistance, and power losses. For the latter, a comparison with results obtained from dark lock-in thermography gives quantitative agreement, provided that the cells are not severely shunted.

  6. Spin Injection in Indium Arsenide

    Directory of Open Access Journals (Sweden)

    Mark eJohnson

    2015-08-01

    Full Text Available In a two dimensional electron system (2DES, coherent spin precession of a ballistic spin polarized current, controlled by the Rashba spin orbit interaction, is a remarkable phenomenon that’s been observed only recently. Datta and Das predicted this precession would manifest as an oscillation in the source-drain conductance of the channel in a spin-injected field effect transistor (Spin FET. The indium arsenide single quantum well materials system has proven to be ideal for experimental confirmation. The 2DES carriers have high mobility, low sheet resistance, and high spin orbit interaction. Techniques for electrical injection and detection of spin polarized carriers were developed over the last two decades. Adapting the proposed Spin FET to the Johnson-Silsbee nonlocal geometry was a key to the first experimental demonstration of gate voltage controlled coherent spin precession. More recently, a new technique measured the oscillation as a function of channel length. This article gives an overview of the experimental phenomenology of the spin injection technique. We then review details of the application of the technique to InAs single quantum well (SQW devices. The effective magnetic field associated with Rashba spin-orbit coupling is described, and a heuristic model of coherent spin precession is presented. The two successful empirical demonstrations of the Datta Das conductance oscillation are then described and discussed.

  7. 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.

  8. Origin of Open-Circuit Voltage Loss in Polymer Solar Cells and Perovskite Solar Cells.

    Science.gov (United States)

    Kim, Hyung Do; Yanagawa, Nayu; Shimazaki, Ai; Endo, Masaru; Wakamiya, Atsushi; Ohkita, Hideo; Benten, Hiroaki; Ito, Shinzaburo

    2017-06-14

    Herein, the open-circuit voltage (V OC ) loss in both polymer solar cells and perovskite solar cells is quantitatively analyzed by measuring the temperature dependence of V OC to discuss the difference in the primary loss mechanism of V OC between them. As a result, the photon energy loss for polymer solar cells is in the range of about 0.7-1.4 eV, which is ascribed to temperature-independent and -dependent loss mechanisms, while that for perovskite solar cells is as small as about 0.5 eV, which is ascribed to a temperature-dependent loss mechanism. This difference is attributed to the different charge generation and recombination mechanisms between the two devices. The potential strategies for the improvement of V OC in both solar cells are further discussed on the basis of the experimental data.

  9. Solar heating of GaAs nanowire solar cells.

    Science.gov (United States)

    Wu, Shao-Hua; Povinelli, Michelle L

    2015-11-30

    We use a coupled thermal-optical approach to model the operating temperature rise in GaAs nanowire solar cells. We find that despite more highly concentrated light absorption and lower thermal conductivity, the overall temperature rise in a nanowire structure is no higher than in a planar structure. Moreover, coating the nanowires with a transparent polymer can increase the radiative cooling power by 2.2 times, lowering the operating temperature by nearly 7 K.

  10. Cycle life status of SAFT VOS nickel-cadmium cells

    Science.gov (United States)

    Goualard, Jacques

    1993-01-01

    The SAFT prismatic VOS Ni-Cd cells have been flown in geosynchronous orbit since 1977 and in low earth orbit since 1983. Parallel cycling tests are performed by several space agencies in order to determine the cycle life for a wide range of temperature and depth of discharge (DOD). In low Earth orbit (LEO), the ELAN program is conducted on 24 Ah cells by CNES and ESA at the European Battery Test Center at temperatures ranging from 0 to 27 C and DOD from 10 to 40 percent. Data are presented up to 37,000 cycles. One pack (X-80) has achieved 49,000 cycles at 10 C and 23 percent DOD. The geosynchronous orbit simulation of a high DOD test is conducted by ESA on 3 batteries at 10 C and 70, 90, and 100 percent DOD. Thirty-one eclipse seasons are completed, and no signs of degradation have been found. The Air Force test at CRANE on 24 Ah and 40 Ah cells at 20 C and 80 percent DOD has achieved 19 shadow periods. Life expectancy is discussed. The VOS cell technology could be used for the following: (1) in geosynchronous conditions--15 yrs at 10-15 C and 80 percent DOD; and (2) in low earth orbit--10 yrs at 5-15 C and 25-30 percent DOD.

  11. Semi-transparent polymer solar cells

    Science.gov (United States)

    Romero-Gómez, Pablo; Pastorelli, Francesco; Mantilla-Pérez, Paola; Mariano, Marina; Martínez-Otero, Alberto; Elias, Xavier; Betancur, Rafael; Martorell, Jordi

    2015-01-01

    Over the last three decades, progress in the organic photovoltaic field has resulted in some device features which make organic cells applicable in electricity generation configurations where the standard silicon-based technology is not suitable, for instance, when a semi-transparent photovoltaic panel is needed. When the thin film solar cell performance is evaluated in terms of the device's visible transparency and power conversion efficiency, organic solar cells offer the most promising solution. During the last three years, research in the field has consolidated several approaches for the fabrication of high performance semi-transparent organic solar cells. We have grouped these approaches under three categories: devices where the absorber layer includes near-infrared absorption polymers, devices incorporating one-dimensional photonic crystals, and devices with a metal cavity light trapping configuration. We herein review these approaches.

  12. Amorphous silicon crystalline silicon heterojunction solar cells

    CERN Document Server

    Fahrner, Wolfgang Rainer

    2013-01-01

    Amorphous Silicon/Crystalline Silicon Solar Cells deals with some typical properties of heterojunction solar cells, such as their history, the properties and the challenges of the cells, some important measurement tools, some simulation programs and a brief survey of the state of the art, aiming to provide an initial framework in this field and serve as a ready reference for all those interested in the subject. This book helps to "fill in the blanks" on heterojunction solar cells. Readers will receive a comprehensive overview of the principles, structures, processing techniques and the current developmental states of the devices. Prof. Dr. Wolfgang R. Fahrner is a professor at the University of Hagen, Germany and Nanchang University, China.

  13. Organic solar cells fundamentals, devices, and upscaling

    CERN Document Server

    Rand, Barry P

    2014-01-01

    Solution-Processed DonorsB. Burkhart, B. C. ThompsonSmall-Molecule and Vapor-Deposited Organic Photovoltaics R. R. Lunt, R. J. HolmesAcceptor Materials for Solution-Processed Solar Cells Y. HeInterfacial Layers R. Po, C. Carbonera, A. BernardiElectrodes in Organic Photovoltaic Cells S. Yoo, J.-Y. Lee, H. Kim, J. LeeTandem and Multi-Junction Organic Solar Cells J. Gilot, R. A. J. JanssenBulk Heterojunction Morphology Control and Characterization T. Wang, D. G. LidzeyOptical Modeling and Light Management

  14. Polymer-Fullerene Bulk Heterojunction Solar Cells

    OpenAIRE

    Deibel, Carsten; Dyakonov, Vladimir

    2010-01-01

    Organic solar cells have the potential to be low-cost and efficient solar energy converters, with a promising energy balance. They are made from carbon-based semiconductors, which exhibit favourable light absorption and charge generation properties, and can be manufactured by low temperature processes such as printing from solvent-based inks, which are compatible with flexible plastic substrates or even paper. In this review, we will present an overview of the physical function of organic sol...

  15. Microbial solar cells: applying photosynthetic and electrochemically active organisms

    NARCIS (Netherlands)

    Strik, D.P.B.T.B.; Timmers, R.A.; Helder, M.; Steinbusch, K.J.J.; Hamelers, H.V.M.; Buisman, C.J.N.

    2011-01-01

    Microbial solar cells (MSCs) are recently developed technologies that utilize solar energy to produce electricity or chemicals. MSCs use photoautotrophic microorganisms or higher plants to harvest solar energy, and use electrochemically active microorganisms in the bioelectrochemical system to

  16. Solar destillation cell with microporous membrane connect to solar heater

    Energy Technology Data Exchange (ETDEWEB)

    Odicino, L.A.; Marchese, J. [Univ. Nacional de San Luis, Lab. de Energia Solar y Lab. de Cs. de Superficie y Medios Porosos Chacabuco y Pedernera, San Luis (Argentina); Lesino, G. [Univ. Nacional de Salta, INENCO, Salta (Argentina)

    2000-07-01

    In earlier papers [Odicino,Eurosun 1998,1999] we presented the results of a system of distillation through microporous membranes, where this process is driven by temperature differences between the two sides of the membrane. In the former experiments the system was thermostatified in order to produce the temperature differences necessary for the function of the distillation cell, and it allowed us to effect the experimental determinations that conduce to the knowledge of the behavior of the cell and in particular the membrane as a function of the variation of parameters such as feeding flux, concentration, and temperature gradient. For these experiences the difference of temperature is given by a solar heater, which provides the necessary energy and at a cost the sufficiently low thing as to make the process of distillation economically viable. Two identic cells were constructed that were connected in series in a solar heater, inserting them between the collectors exit duct and the flux that goes to the storing tank, as this is the region of maximum temperature in the system. We find a relation among the efficiency {eta} of a solar heather and the permeado flow through the membrane. (au)

  17. Dye-sensitised solar cell (artificial photosynthesis)

    CSIR Research Space (South Africa)

    Le Roux, Lukas J

    2006-02-01

    Full Text Available is the nano- crystalline TiO2dye- sensitised solar cell (DSC), in conjunction with several new concepts, such as nanotechnology and molecular devices. An efficient and low-cost cell can be produced by using simple materials. The production process generates...

  18. Walking-Beam Solar-Cell Conveyor

    Science.gov (United States)

    Feder, H.; Frasch, W.

    1982-01-01

    Microprocessor-controlled walking-beam conveyor moves cells between work stations in automated assembly line. Conveyor has arm at each work station. In unison arms pick up all solar cells and advance them one station; then beam retracks to be in position for next step. Microprocessor sets beam stroke, speed, and position.

  19. Adipose Tissue-Derived Stem Cell Imaging Using Cadmium-Free Quantum Dots

    OpenAIRE

    Miyazaki, Yoshiyuki; Yukawa, Hiroshi; Nishi, Hiroyasu; Okamoto, Yukihiro; Kaji, Noritada; Torimoto, Tsukasa; Baba, Yoshinobu

    2013-01-01

    Quantum dots (QDs) have received much attention for biomolecule and cell imaging applications because of their superior optical properties such as high quantum efficiency, size-tunable emission, and resistance to photobleaching process. However, QDs that are commercially available contain cadmium (Cd), a highly toxic element. Thus, the development of Cd-free and less toxic QDs is strongly desired. In this study, we developed Cd-free QDs (ZnS-coated ZnS-AgInS2 solid solution nanoparticles with...

  20. Study of process variables associated with manufacturing hermetically-sealed nickel-cadmium cells

    Science.gov (United States)

    Miller, L.; Doan, D. J.; Carr, E. S.

    1971-01-01

    A program to determine and study the critical process variables associated with the manufacture of aerospace, hermetically-sealed, nickel-cadmium cells is described. The determination and study of the process variables associated with the positive and negative plaque impregnation/polarization process are emphasized. The experimental data resulting from the implementation of fractional factorial design experiments are analyzed by means of a linear multiple regression analysis technique. This analysis permits the selection of preferred levels for certain process variables to achieve desirable impregnated plaque characteristics.

  1. Neutral Color Semitransparent Microstructured Perovskite Solar Cells

    KAUST Repository

    Eperon, Giles E.

    2014-01-28

    Neutral-colored semitransparent solar cells are commercially desired to integrate solar cells into the windows and cladding of buildings and automotive applications. Here, we report the use of morphological control of perovskite thin films to form semitransparent planar heterojunction solar cells with neutral color and comparatively high efficiencies. We take advantage of spontaneous dewetting to create microstructured arrays of perovskite "islands", on a length-scale small enough to appear continuous to the eye yet large enough to enable unattenuated transmission of light between the islands. The islands are thick enough to absorb most visible light, and the combination of completely absorbing and completely transparent regions results in neutral transmission of light. Using these films, we fabricate thin-film solar cells with respectable power conversion efficiencies. Remarkably, we find that such discontinuous films still have good rectification behavior and relatively high open-circuit voltages due to the inherent rectification between the n- and p-type charge collection layers. Furthermore, we demonstrate the ease of "color-tinting" such microstructured perovksite solar cells with no reduction in performance, by incorporation of a dye within the hole transport medium. © 2013 American Chemical Society.

  2. Light-trapping in perovskite solar cells

    Directory of Open Access Journals (Sweden)

    Qing Guo Du

    2016-06-01

    Full Text Available We numerically demonstrate enhanced light harvesting efficiency in both CH3NH3PbI3 and CH(NH22PbI3-based perovskite solar cells using inverted vertical-cone photonic-crystal nanostructures. For CH3NH3PbI3 perovskite solar cells, the maximum achievable photocurrent density (MAPD reaches 25.1 mA/cm2, corresponding to 92% of the total available photocurrent in the absorption range of 300 nm to 800 nm. Our cell shows 6% absorption enhancement compared to the Lambertian limit (23.7 mA/cm2 and has a projected power conversion efficiency of 12.9%. Excellent solar absorption is numerically demonstrated over a broad angular range from 0 to 60 degree for both S- and P- polarizations. For the corresponding CH(NH22PbI3 based perovskite solar cell, with absorption range of 300 nm to 850 nm, we find a MAPD of 29.1 mA/cm2, corresponding to 95.4% of the total available photocurrent. The projected power conversion efficiency of the CH(NH22PbI3 based photonic crystal solar cell is 23.4%, well above the current world record efficiency of 20.1%.

  3. Light-trapping in perovskite solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Du, Qing Guo, E-mail: duqi0001@e.ntu.edu.sg [Department of Physics, University of Toronto, 60 ST. George St., Toronto, Ontario, M5S 1A7 (Canada); Institute of High Performance Computing, A* STAR, Singapore, 138632 (Singapore); Shen, Guansheng [Department of Physics, University of Toronto, 60 ST. George St., Toronto, Ontario, M5S 1A7 (Canada); School of Information and Communication Engineering, Beijing University of Posts and Telecommunications, Beijing 100876 (China); John, Sajeev [Department of Physics, University of Toronto, 60 ST. George St., Toronto, Ontario, M5S 1A7 (Canada); Department of Physics, Soochow University, Suzhou (China)

    2016-06-15

    We numerically demonstrate enhanced light harvesting efficiency in both CH{sub 3}NH{sub 3}PbI{sub 3} and CH(NH{sub 2}){sub 2}PbI{sub 3}-based perovskite solar cells using inverted vertical-cone photonic-crystal nanostructures. For CH{sub 3}NH{sub 3}PbI{sub 3} perovskite solar cells, the maximum achievable photocurrent density (MAPD) reaches 25.1 mA/cm{sup 2}, corresponding to 92% of the total available photocurrent in the absorption range of 300 nm to 800 nm. Our cell shows 6% absorption enhancement compared to the Lambertian limit (23.7 mA/cm{sup 2}) and has a projected power conversion efficiency of 12.9%. Excellent solar absorption is numerically demonstrated over a broad angular range from 0 to 60 degree for both S- and P- polarizations. For the corresponding CH(NH{sub 2}){sub 2}PbI{sub 3} based perovskite solar cell, with absorption range of 300 nm to 850 nm, we find a MAPD of 29.1 mA/cm{sup 2}, corresponding to 95.4% of the total available photocurrent. The projected power conversion efficiency of the CH(NH{sub 2}){sub 2}PbI{sub 3} based photonic crystal solar cell is 23.4%, well above the current world record efficiency of 20.1%.

  4. Fruit based Dye Sensitized Solar Cells

    Science.gov (United States)

    Ung, M. C.; Sipaut, C. S.; Dayou, J.; Liow, K. S.; Kulip, J.; Mansa, R. F.

    2017-07-01

    Dye Sensitized Solar Cell (DSSC) was first discovered in 1991 by O’regan and Gratzel. This new type of solar cell was reported to have lower production cost with efficiency as high as 12% which is comparable to conventional silicon solar cell. Initially, it uses ruthenium dye as light sensitizer for the operation. However, DSSC with ruthenium dyes are facing environment friendly issues due to the toxic chemicals and costly purification in processing ruthenium dye. Regardless of the poor performance in DSSC, natural dyes which are easy to prepare, cheap and environmental friendly still appear to be an alternative as dye sensitizer. In this study, dye sensitized solar cells (DSSCs) were fabricated using anthocyanin source dyes extracted from several local fruits. All the extracts absorb a wide range of the visible light and ultraviolet spectrum. Therefore, all of the natural dyes show light absorption properties which is important for a dye sensitizer. A DSSC is comprised of conductive substrate, nanoporous semiconductor TiO2 layer, dye sensitizer, electrolyte with redox couple and a counter electrode with catalyst. In this study, the effect of different light source and different counter electrode are been investigated. However, it is vital to know that further research need to do more on the locally Borneo sourced dyes to evaluate and enhance their performance in Dye Sensitized Solar Cell.

  5. Space Radiation Effect on Si Solar Cells

    Directory of Open Access Journals (Sweden)

    Jae-Jin Lee

    2008-12-01

    Full Text Available High energy charged particles are trapped by geomagnetic field in the region named Van Allen Belt. These particles can move to low altitude along magnetic field and threaten even low altitude spacecraft. Space Radiation can cause equipment failures and on occasions can even destroy operations of satellites in orbit. Sun sensors aboard Science and Technology Satellite (STSAT-1 was designed to detect sun light with silicon solar cells which performance was degraded during satellite operation. In this study, we try to identify which particle contribute to the solar cell degradation with ground based radiation facilities. We measured the short circuit current after bombarding electrons and protons on the solar cells same as STSAT-1 sun sensors. Also we estimated particle flux on the STSAT-1 orbit with analyzing NOAA POES particle data. Our result clearly shows STSAT-1 solar cell degradation was caused by energetic protons which energy is about 700 keV to 1.5 MeV. Our result can be applied to estimate solar cell conditions of other satellites.

  6. Development and characterization of PCDTBT:CdSe QDs hybrid solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Dixit, Shiv Kumar, E-mail: shivkumardixit.7@gmail.com; Bhatnagar, Chhavi, E-mail: shivkumardixit.7@gmail.com; Kumari, Anita, E-mail: shivkumardixit.7@gmail.com; Madhwal, Devinder, E-mail: shivkumardixit.7@gmail.com; Bhatnagar, P. K., E-mail: shivkumardixit.7@gmail.com; Mathur, P. C., E-mail: shivkumardixit.7@gmail.com [Department of Electronic Science, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021 (India)

    2014-10-15

    Solar cell consisting of low band gap polymer poly[N-900-hepta-decanyl-2,7-carbazole-alt-5,5-(40,70-di-2-thienyl-20,10, 30-benzothiadiazole)] (PCDTBT) as donor and cadmium selenide/zinc sulphide (CdSe/ZnS) core shell quantum dots (QDs) as an acceptor has been developed. The absorption measurements show that the absorption coefficient increases in bulk heterojunction (BHJ) structure covering broad absorption spectrum (200nm–700nm). Also, the photoluminescence (PL) of the PCDTBT:QDs film is found to decrease by an order of magnitude showing a significant transfer of electrons to the QDs. With this approach and under broadband white light with an irradiance of 8.19 mW/cm{sup 2}, we have been able to achieve a power conversion efficiency (PCE) of 3.1 % with fill factor 0.42 for our typical solar cell.

  7. Recombination barrier layers in solid-state quantum dot-sensitized solar cells

    KAUST Repository

    Roelofs, Katherine E.

    2012-06-01

    By replacing the dye in the dye-sensitized solar cell design with semiconductor quantum dots as the light-absorbing material, solid-state quantum dot-sensitized solar cells (ss-QDSSCs) were fabricated. Cadmium sulfide quantum dots (QDs) were grown in situ by successive ion layer adsorption and reaction (SILAR). Aluminum oxide recombination barrier layers were deposited by atomic layer deposition (ALD) at the TiO2/hole-conductor interface. For low numbers of ALD cycles, the Al2O3 barrier layer increased open circuit voltage, causing an increase in device efficiency. For thicker Al2O3 barrier layers, photocurrent decreased substantially, leading to a decrease in device efficiency. © 2012 IEEE.

  8. Doctor Blade-Coated Polymer Solar Cells

    KAUST Repository

    Cho, Nam Chul

    2016-10-25

    In this work, we report polymer solar cells based on blade-coated P3HT:PC71BM and PBDTTT-EFT:PC71BM bulk heterojunction photoactive layers. Enhanced power conversion efficiency of 2.75 (conventional structure) and 3.03% (inverted structure) with improved reproducibility was obtained from blade-coated P3HT:PC71BM solar cells, compared to spin-coated ones. Furthermore, by demonstrating 3.10% efficiency flexible solar cells using blade-coated PBDTTT-EFT:PC71BM films on the plastic substrates, we suggest the potential applicability of blade coating technique to the high throughput roll-to-roll fabrication systems.

  9. Fabricating solar cells with silicon nanoparticles

    Science.gov (United States)

    Loscutoff, Paul; Molesa, Steve; Kim, Taeseok

    2014-09-02

    A laser contact process is employed to form contact holes to emitters of a solar cell. Doped silicon nanoparticles are formed over a substrate of the solar cell. The surface of individual or clusters of silicon nanoparticles is coated with a nanoparticle passivation film. Contact holes to emitters of the solar cell are formed by impinging a laser beam on the passivated silicon nanoparticles. For example, the laser contact process may be a laser ablation process. In that case, the emitters may be formed by diffusing dopants from the silicon nanoparticles prior to forming the contact holes to the emitters. As another example, the laser contact process may be a laser melting process whereby portions of the silicon nanoparticles are melted to form the emitters and contact holes to the emitters.

  10. Stability Issues on Perovskite Solar Cells

    Directory of Open Access Journals (Sweden)

    Xing Zhao

    2015-11-01

    Full Text Available Organo lead halide perovskite materials like methylammonium lead iodide (CH3NH3PbI3 and formamidinium lead iodide (HC(NH22PbI3 show superb opto-electronic properties. Based on these perovskite light absorbers, power conversion efficiencies of the perovskite solar cells employing hole transporting layers have increased from 9.7% to 20.1% within just three years. Thus, it is apparent that perovskite solar cell is a promising next generation photovoltaic technology. However, the unstable nature of perovskite was observed when exposing it to continuous illumination, moisture and high temperature, impeding the commercial development in the long run and thus becoming the main issue that needs to be solved urgently. Here, we discuss the factors affecting instability of perovskite and give some perspectives about further enhancement of stability of perovskite solar cell.

  11. Perovskite Solar Cells: Potentials, Challenges, and Opportunities

    Directory of Open Access Journals (Sweden)

    Muhammad Imran Ahmed

    2015-01-01

    Full Text Available Heralded as a major scientific breakthrough of 2013, organic/inorganic lead halide perovskite solar cells have ushered in a new era of renewed efforts at increasing the efficiency and lowering the cost of solar energy. As a potential game changer in the mix of technologies for alternate energy, it has emerged from a modest beginning in 2012 to efficiencies being claimed at 20.1% in a span of just two years. This remarkable progress, encouraging at one end, also points to the possibility that the potential may still be far from being fully realized. With greater insight into the photophysics involved and optimization of materials and methods, this technology stands to match or even exceed the efficiencies for single crystal silicon solar cells. With thin film solution processability, applicability to flexible substrates, and being free of liquid electrolyte, this technology combines the benefits of Dye Sensitized Solar Cells (DSSCs, Organic Photovoltaics (OPVs, and thin film solar cells. In this review we present a brief historic perspective to this development, take a cognizance of the current state of the art, and highlight challenges and the opportunities.

  12. Method of fabricating a solar cell array

    Science.gov (United States)

    Lazzery, Angelo G.; Crouthamel, Marvin S.; Coyle, Peter J.

    1982-01-01

    A first set of pre-tabbed solar cells are assembled in a predetermined array with at least part of each tab facing upward, each tab being fixed to a bonding pad on one cell and abutting a bonding pad on an adjacent cell. The cells are held in place with a first vacuum support. The array is then inverted onto a second vacuum support which holds the tabs firmly against the cell pads they abut. The cells are exposed to radiation to melt and reflow the solder pads for bonding the tab portions not already fixed to bonding pads to these pads.

  13. Questionable effects of antireflective coatings on inefficiently cooled solar cells

    DEFF Research Database (Denmark)

    Akhmatov, Vladislav; Galster, Georg; Larsen, Esben

    1998-01-01

    A model for temperature effects in p-n junction solar cells is introduced. The temperature of solar cells and the losses in the solar cell junction region caused by elevating temperature are discussed. The model developed is examined for low-cost silicon solar cells. In order to improve the shape...... of the output power and efficiency curves throughout the day the coherence between technical parameters of the solar cells and the climate in the operation region is observed and examined. It is shown how the drop in output power around noon can be avoided by fitting technical parameters of the solar cells...

  14. The effects of parathyroid hormone and estradiol on cadmium accumulation by Madin-Darby canine kidney cells

    Energy Technology Data Exchange (ETDEWEB)

    Flanagan, J.L.

    1990-01-01

    Chronic exposure to the toxic metal cadmium causes osteomalacia, osteoporosis, increased serum parathyroid hormone, renal stone formation, hypercalciuria and renal tubular dysfunction, reflecting one or more disturbances of calcium homeostasis. Since renal cadmium (Cd[sup 2+]) transport proceeds in both proximal and distal tubules and parathyroid hormone (PTH) regulates calcium reabsorption at distal nephron sites, it was postulated that PTH may also stimulate Cd[sup 2+] transport in distal tubules. Madin-Darby canine kidney (MDCK) cells, which express a distal phenotype including PTH-sensitive adenylate cyclase and calcium transport, were used as the cell model for the present study. Cadmium uptake was measured using [[sup 109]Cd[sup 2+

  15. Kesterite Deposited by Spray Pyrolysis for Solar Cell Applications

    OpenAIRE

    Espindola Rodriguez, Moises

    2015-01-01

    Solar cells generate electrical power by direct conversion of solar radiation into electricity using semiconductors. Once produced, the solar cells do not require the use of water; operate in silence and can be easily installed almost everywhere, as solar panels with low technological risk. In this thesis new photovoltaic materials and solar cells are investigated. From the beginning of the semiconductor era, silicon has been present; the semiconductor theory improved with the silicon tec...

  16. High throughput solar cell ablation system

    Science.gov (United States)

    Harley, Gabriel; Pass, Thomas; Cousins, Peter John; Viatella, John

    2012-09-11

    A solar cell is formed using a solar cell ablation system. The ablation system includes a single laser source and several laser scanners. The laser scanners include a master laser scanner, with the rest of the laser scanners being slaved to the master laser scanner. A laser beam from the laser source is split into several laser beams, with the laser beams being scanned onto corresponding wafers using the laser scanners in accordance with one or more patterns. The laser beams may be scanned on the wafers using the same or different power levels of the laser source.

  17. Solar cell contact formation using laser ablation

    Science.gov (United States)

    Harley, Gabriel; Smith, David; Cousins, Peter

    2012-12-04

    The formation of solar cell contacts using a laser is described. A method of fabricating a back-contact solar cell includes forming a poly-crystalline material layer above a single-crystalline substrate. The method also includes forming a dielectric material stack above the poly-crystalline material layer. The method also includes forming, by laser ablation, a plurality of contacts holes in the dielectric material stack, each of the contact holes exposing a portion of the poly-crystalline material layer; and forming conductive contacts in the plurality of contact holes.

  18. Solar Cells Having a Nanostructured Antireflection Layer

    DEFF Research Database (Denmark)

    2013-01-01

    An solar cell having a surface in a first material is provided, the optical device having a non-periodic nanostructure formed in the surface, the nanostructure comprising a plurality of cone -haped structures wherein the cones are distributed non-periodically on the surface and have a random height...... distribution, at least a part of the cone-shaped structures having a height of at least 100 nm. The first material may be SiC or GaN. A method of manufacturing a non-periodic nanostructured surface on a solar cell, is furthermore provided, the method comprising the steps of providing a surface comprising Si...

  19. Efficient upconversion systems for silicon solar cells

    OpenAIRE

    Löper, P.; Goldschmidt, J. C.; Peters, M.; Biner, D.; Krämer, K.; Schultz, O.; Glunz, S.W.; Luther, J.

    2007-01-01

    Frequency upconversion of sub-bandgap photons is one approach to push the efficiency limit of solar cells with one bandgap. A highly efficient upconversion system is Erbium doped NaYF4. In this paper we present photoluminescence studies on NaYF4 with 10%, 20% and 30% Erbium doping. We show experimental results of an upconversion system consisting of an upconverting powder on a bifacial silicon solar cell. The system has a quantum efficiency of 2.5·10-3% at 1520nm wavelength. We model the effi...

  20. Origami-enabled deformable silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Rui; Huang, Hai; Liang, Hanshuang; Liang, Mengbing [School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287 (United States); Tu, Hongen; Xu, Yong [Electrical and Computer Engineering, Wayne State University, 5050 Anthony Wayne Dr., Detroit, Michigan 48202 (United States); Song, Zeming; Jiang, Hanqing, E-mail: hanqing.jiang@asu.edu [School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, Arizona 85287 (United States); Yu, Hongyu, E-mail: hongyu.yu@asu.edu [School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287 (United States); School of Earth and Space Exploration, Arizona State University, Tempe, Arizona 85287 (United States)

    2014-02-24

    Deformable electronics have found various applications and elastomeric materials have been widely used to reach flexibility and stretchability. In this Letter, we report an alternative approach to enable deformability through origami. In this approach, the deformability is achieved through folding and unfolding at the creases while the functional devices do not experience strain. We have demonstrated an example of origami-enabled silicon solar cells and showed that this solar cell can reach up to 644% areal compactness while maintaining reasonable good performance upon cyclic folding/unfolding. This approach opens an alternative direction of producing flexible, stretchable, and deformable electronics.

  1. Inhibiting Cadmium Transport Process in Root Cells of Plants: A Review

    Directory of Open Access Journals (Sweden)

    ZHAO Yan-ling

    2016-05-01

    Full Text Available Cadmium(Cd is the most common element found in the heavy-metal contaminated soils in China. Roots of rice and vegetables can concentrate Cd from acid soils, and then transport Cd to above-ground parts. Cd in edible part of plants directly influences the food safety. Cellwall, plasma membrane and organells of root cells in plant can discriminate Cd from other elements. A lot of Cd can be fixed in root cells by precipitation, complexation, compartmentation, and so on, to inhibit its transport from roots to shoot and guarantee the physiological activities in above-ground parts carrying out normally. This paper summarized recent advance on inhibiting Cd transport process in subcellular fractions of root cells of plants, which is in advantage of exploring excellent germplasms and gene resources in the future.

  2. Cadmium uptake by Caco-2 cells: effects of Cd complexation by chloride, glutathione, and phytochelatins.

    Science.gov (United States)

    Jumarie, C; Fortin, C; Houde, M; Campbell, P G; Denizeau, F

    2001-01-01

    Short-term cadmium uptake by the highly differentiated TC7 clone of enterocytic-like Caco-2 cells was studied as a function of Cd speciation. For low metal concentrations and with a constant free [Cd(2+)] = 43 nM, initial uptake rates of (109)Cd increased linearly as a function of increasing concentration of chlorocomplexes (Sigma[(109)CdCl(2-n)(n)]) over the range from 0 to 250 nM. When normalized as a function of the metal concentration, the absorption rate for the chlorocomplexes was less than that estimated for uptake of the free Cd(2+) cation. Metal absorption decreased upon organic ligand addition in the exposure media, but much less than predicted from the assumption that only inorganic metal species would be transported. Under exposure conditions where the concentration of each of the inorganic species was kept constant, (109)Cd uptake increased with increasing concentrations of cadmium glutathione ((109)Cd-GSH) or phytochelatin ((109)Cd-hmPC(3)) complexes. A specific system of very high affinity but low capacity has been characterized for (109)Cd-GSH transport, whereas accumulation data increased linearly with (109)Cd-hmPC(3) up to 6 microM. Comparison among uptake data for 0.3 microM inorganic (109)Cd, (109)Cd-GSH, or (109)Cd-hmPC(3) yields the following accumulation ratios: Cd-GSH/Cd(inorg) = 0.2; Cd-hmPC(3)/Cd(inorg) = 0.5. These results clearly show that Cd(2+) is not the exclusive metal species participating in Cd absorption, though, for comparable Cd concentrations, its contribution to transport would be more important than that of other species. Cadmium bound to thiol-containing peptides may be absorbed via transport systems that differ from those involved in absorption of the inorganic metal species. Copyright 2001 Academic Press.

  3. CIGS2 Thin-Film Solar Cells on Flexible Foils for Space Power

    Science.gov (United States)

    Dhere, Neelkanth G.; Ghongadi, Shantinath R.; Pandit, Mandar B.; Jahagirdar, Anant H.; Scheiman, David

    2002-01-01

    CuIn(1-x)Ga(x)S2 (CIGS2) thin-film solar cells are of interest for space power applications because of the near optimum bandgap for AM0 solar radiation in space. CIGS2 thin film solar cells on flexible stainless steel (SS) may be able to increase the specific power by an order of magnitude from the current level of 65 Wkg(sup -1). CIGS solar cells are superior to the conventional silicon and gallium arsenide solar cells in the space radiation environment. This paper presents research efforts for the development of CIGS2 thin-film solar cells on 127 micrometers and 20 micrometers thick, bright-annealed flexible SS foil for space power. A large-area, dual-chamber, inline thin film deposition system has been fabricated. The system is expected to provide thickness uniformity of plus or minus 2% over the central 5" width and plus or minus 3% over the central 6" width. During the next phase, facilities for processing larger cells will be acquired for selenization and sulfurization of metallic precursors and for heterojunction CdS layer deposition both on large area. Small area CIGS2 thin film solar cells are being prepared routinely. Cu-rich Cu-Ga/In layers were sputter-deposited on unheated Mo-coated SS foils from CuGa (22%) and In targets. Well-adherent, large-grain Cu-rich CIGS2 films were obtained by sulfurization in a Ar: H2S 1:0.04 mixture and argon flow rate of 650 sccm, at the maximum temperature of 475 C for 60 minutes with intermediate 30 minutes annealing step at 120 C. Samples were annealed at 500 C for 10 minutes without H2S gas flow. The intermediate 30 minutes annealing step at 120 C was changed to 135 C. p-type CIGS2 thin films were obtained by etching the Cu-rich layer segregated at the surface using dilute KCN solution. Solar cells were completed by deposition of CdS heterojunction partner layer by chemical bath deposition, transparent-conducting ZnO/ZnO: Al window bilayer by RF sputtering, and vacuum deposition of Ni/Al contact fingers through metal

  4. Evaluation of solar cells for potential space satellite power applications

    Science.gov (United States)

    1977-01-01

    The evaluation focused on the following subjects: (1) the relative merits of alternative solar cell materials, based on performance and availability, (2) the best manufacturing methods for various solar cell options and the effects of extremely large production volumes on their ultimate costs and operational characteristics, (3) the areas of uncertainty in achieving large solar cell production volumes, (4) the effects of concentration ratios on solar array mass and system performance, (5) the factors influencing solar cell life in the radiation environment during transport to and in geosynchronous orbit, and (6) the merits of conducting solar cell manufacturing operations in space.

  5. Genotoxic effects of cadmium chloride on human amniotic fluid cells cultured in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Fogu, G. [Sassari Univ., Sassari (Italy). Dept. of Physiological, Biochemical and Cellular sciences; Sassari Univ., Sassari (Italy). Centre of Clinical Genetics; Congiu, A. M.; Sini, M. C.; Ladu, R. [Sassari Univ., Sassari (Italy). Dept. of Physiological, Biochemical and Cellular sciences; Campus, P. M.; Sanna, R.; Soro, G. [Sassari Univ., Sassari (Italy). Centre of Clinical Genetics

    2000-12-01

    In this study it has been reported the results of cytogenetic tests, namely a search for chromosome aberrations (CA) and sister chromatid exchanges (SCEs), performed on human amniotic fluid cells cultured and treated with Cadmium chloride. The cells from primary cultures were exposed to CdCl{sub 2} at 1 {mu}M and 10 {mu}M for 24 h. At the higher dose, no metaphases were scored and at the lower dose (1 {mu}M) no effects were evident on cell proliferation, and no chromosome aberrations were found. In the subsequent experiments were used cells from subcultures exposed to 1 {mu}M and 5 {mu}M CdCl{sub 2}. At the 5 {mu}M dose was evident the induction of chromatid breaks, while the frequency of sister chromatid exchanges shows a small increase, not statistically significant at the dose of 1 {mu}M. In this study it was positively demonstrated that amniotic fluid cells grown in vitro are reliable for testing various mutagenic or teratogenic substances. With regard to cadmium treatment results, it is evident a clastogenic effect of cadmium chloride but not a significant induction of SCEs. [Italian] In questo studio abbiamo riportato i risultati dei tests citogenici di valutazione degli scambi fra cromatidi fratelli (SCEs) e di induzione di aberrazioni cromosomiche (CA) condotti su colture cellulari di liquido amniotico umano, trattate con cloruro di cadmio. Le cellule delle colture primarie venivano esposte al CdCl{sub 2} a concentrazioni di 1 {mu}M 10 {mu}M per 24 h. Alla dose piu' alta (10 {mu}M) non sono state osservate metafasi, mentre alla dose piu' bassa (1 {mu}M) non sono stati evidenziati ne' effetti sulla proliferazione cellulare ne' CA. Nei successivi esperimenti il CdC{sub 2} e' stato testato su subcolture cellulari alle dosi di 1 {mu}M e 5 {mu}M. Alla dose di 5 {mu}M sono state evidenziate rotture cromatidiche, mentre la frequenza di SCE alla dose di 1 {mu}M ha mostrato un piccolo incremento, statisticamente non significativo. In questo

  6. Solar-Cell Encapsulation by One-Step Lamination

    Science.gov (United States)

    Sarbolouki, M. N.

    1983-01-01

    Simple method of potting solar cells reduces encapsulating to one-step lamination process. Simplified process saves time and expense. Potting material is added to two inside faces of solar-cell assembly before they are sandwiched and cured.

  7. OPTOELECTRONIC PROPERTIES OF CdS – AgInS2 SOLAR CELLS

    Directory of Open Access Journals (Sweden)

    M. A. Abdullaev

    2016-01-01

    Full Text Available Aim. To conduct experimental studies of optoelectronic properties of CdS - AgInS2 solar cells.Methods. AgInS2 films for solar cell CdS-AgInS2 were obtained by magnetron sputtering of crystalline targets derived from bulk ingots. Cadmium sulfide layers were deposited on the AgInS2 films by an electrochemical method in cadmium salts solution, thiourea and ammonia. AgInS2 bulk crystals were obtained in two stages: a direct fusion of the primary components (99,999 in a stoichiometric ratio, followed by directional solidification in a vertical furnace; re-synthesis has been performed on a staggered basis by heating the obtained ingots at temperatures close to the melting points of elements in the two-zone horizontal furnace.Findings. The paper presents the results of experimental studies of the electrical properties and photosensitivity of CdS-AgInS2 film heterojunction obtained by the magnetron. We measured the current-voltage characteristics and quantum efficiency of photoconversion at temperatures up to 250-356 K. We also identified the short circuit current of up to 25 mA/cm2 and open circuit voltage of 0.38 V.Conclusions. The study of the properties of solar cells in recent years has an important place. The results presented in the work would contribute to more efficient conversion of solar energy into electricity.

  8. Electrical overstress failure in silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Pease, R.L.; Barnum, J.R.; van Lint, V.A.J.; Vulliet, W.V.; Wrobel, T.F.

    1982-11-01

    A solar-cell electrical-overstress-failure model and the results of experimental measurements of threshold pulsed failure currents on four types of silicon solar cells are presented. The transient EMP field surrounding a lightning stroke has been identified as a potential threat to a photovoltaic array, yet failure analysis of solar cells in a pulsed environment had not previously been reported. Failure in the low-resistivity concentrator cells at pulse widths between 1 ..mu..s and 1 ms occurred initially in the junction. Finger damage in the form of silver melting occurs at currents only slightly greater than that required for junction damage. The result of reverse-bias transient-overstress tests on high-resistivity (10 ..cap omega..cm) cells demonstrated that the predominant failure mode was due to edge currents. These flat-plate cells failed at currents of only 4 to 20 A, which is one or two orders of magnitude below the model predictions. It thus appears that high-resistivity flat-plate cells are quite vulnerable to electrical overstress which could be produced by a variety of mechanisms.

  9. Phthalocyanine Blends Improve Bulk Heterojunction Solar Cells

    Science.gov (United States)

    Varotto, Alessandro; Nam, Chang-Yong; Radivojevic, Ivana; Tomé, Joao; Cavaleiro, José A.S.; Black, Charles T.; Drain, Charles Michael

    2010-01-01

    A core phthalocyanine platform allows engineering the solubility properties the band gap; shifting the maximum absorption toward the red. A simple method to increase the efficiency of heterojunction solar cells uses a self-organized blend of the phthalocyanine chromophores fabricated by solution processing. PMID:20136126

  10. Solar Cell Efficiency Tables (Version 51)

    Energy Technology Data Exchange (ETDEWEB)

    Levi, Dean H [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Green, Martin A. [University of New South Wales; Hishikawa, Yoshihiro [National Institute of Advanced Industrial Science and Technology (AIST); Dunlop, Ewan D. [European Commission-Joint Research Centre; Hohl-Ebinger, Jochen [Fraunhofer Institute for Solar Energy Systems; Ho-Baillie, Anita W. Y. [University of New South Wales

    2017-12-14

    Consolidated tables showing an extensive listing of the highest independently confirmed efficiencies for solar cells and modules are presented. Guidelines for inclusion of results into these tables are outlined and new entries since July 2017 are reviewed, together with progress over the last 25 years. Appendices are included documenting area definitions and also listing recognised test centres.

  11. Fuel Cell / electrolyser, Solar Photovoltaic Powered

    Directory of Open Access Journals (Sweden)

    Chioncel Cristian Paul

    2012-01-01

    Full Text Available The paper presents experimental obtained results in the operation ofelectrolyzer powered by solar photovoltaic modules, for the waterelectrolysis and with the obtained hydrogen and oxygen proceeds tothe operation in fuel cell mode, type PEM. The main operatingparameters and conditions to optimize the energy conversion on thesolar-hydrogen-electricity cycle are highlighted, so that those arecomparable or superior to conventional cycles.

  12. PHOTOELECTROCHEMICAL SOLAR CELLS BASED ON DYE ...

    African Journals Online (AJOL)

    interfacial energetics [23], and altering the particle morphology [ 4,25,26]. According to the university. of Notre Dame and NASA demonstrations, the carbon nanotubes could help to make nanoparticle- based solar cells more efficient and practical. The present attained of 10% -11°/o energy conversion efficiency of DSC ...

  13. Solar cell power systems for space vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, N.W. (Inst. for Defense Analyses, Washington, DC); Karcher, R.W.

    1961-01-01

    On May 3 and 4, 1960, a symposium was held in Washington, DC, under the sponsorship of the Advanced Research Projects Agency by the Institute for Defense Analyses. Ten programs involving solar cell power systems for current US space vehicles conducted under government sponsorship were discussed by the project engineers who directed these programs. The results of that symposium are highlighted and summarized.

  14. Distributed series resistance effects in solar cells

    DEFF Research Database (Denmark)

    Nielsen, Lars Drud

    1982-01-01

    A mathematical treatment is presented of the effects of one-dimensional distributed series resistance in solar cells. A general perturbation theory is developed, including consistently the induced spatial variation of diode current density and leading to a first-order equivalent lumped resistance...

  15. Hybrid Silicon Nanocone–Polymer Solar Cells

    KAUST Repository

    Jeong, Sangmoo

    2012-06-13

    Recently, hybrid Si/organic solar cells have been studied for low-cost Si photovoltaic devices because the Schottky junction between the Si and organic material can be formed by solution processes at a low temperature. In this study, we demonstrate a hybrid solar cell composed of Si nanocones and conductive polymer. The optimal nanocone structure with an aspect ratio (height/diameter of a nanocone) less than two allowed for conformal polymer surface coverage via spin-coating while also providing both excellent antireflection and light trapping properties. The uniform heterojunction over the nanocones with enhanced light absorption resulted in a power conversion efficiency above 11%. Based on our simulation study, the optimal nanocone structures for a 10 μm thick Si solar cell can achieve a short-circuit current density, up to 39.1 mA/cm 2, which is very close to the theoretical limit. With very thin material and inexpensive processing, hybrid Si nanocone/polymer solar cells are promising as an economically viable alternative energy solution. © 2012 American Chemical Society.

  16. Solar cell sheet. Taiyo denchi sheet

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Kazutomi; Nakatani, Kenji; Okaniwa, Hiroshi.

    1989-08-09

    This invention consists of a module sheet containing a thin film solar cell formed on a polymer film substrate, a cushioning sticky film layer and a protective film layer; thickness of module sheet is less than 1000 micron and its bending rigidity of 5 mm thick sample is less than 100 kg-mm {sup 2}. By this, the soalr cell can be wound and unwound in small roll of several cm level. This eliminates the internal wiring in the plural number of cells giving high durability of integrated amorphous solar cell against the repeated bending. The polymer film is films of PET, polysulphone, polyamide, with proper thickness of 30 - 300 micron. 2 figs.

  17. Diketopyrrolopyrrole Polymers for Organic Solar Cells.

    Science.gov (United States)

    Li, Weiwei; Hendriks, Koen H; Wienk, Martijn M; Janssen, René A J

    2016-01-19

    Conjugated polymers have been extensively studied for application in organic solar cells. In designing new polymers, particular attention has been given to tuning the absorption spectrum, molecular energy levels, crystallinity, and charge carrier mobility to enhance performance. As a result, the power conversion efficiencies (PCEs) of solar cells based on conjugated polymers as electron donor and fullerene derivatives as electron acceptor have exceeded 10% in single-junction and 11% in multijunction devices. Despite these efforts, it is notoriously difficult to establish thorough structure-property relationships that will be required to further optimize existing high-performance polymers to their intrinsic limits. In this Account, we highlight progress on the development and our understanding of diketopyrrolopyrrole (DPP) based conjugated polymers for polymer solar cells. The DPP moiety is strongly electron withdrawing and its polar nature enhances the tendency of DPP-based polymers to crystallize. As a result, DPP-based conjugated polymers often exhibit an advantageously broad and tunable optical absorption, up to 1000 nm, and high mobilities for holes and electrons, which can result in high photocurrents and good fill factors in solar cells. Here we focus on the structural modifications applied to DPP polymers and rationalize and explain the relationships between chemical structure and organic photovoltaic performance. The DPP polymers can be tuned via their aromatic substituents, their alkyl side chains, and the nature of the π-conjugated segment linking the units along the polymer chain. We show that these building blocks work together in determining the molecular conformation, the optical properties, the charge carrier mobility, and the solubility of the polymer. We identify the latter as a decisive parameter for DPP-based organic solar cells because it regulates the diameter of the semicrystalline DPP polymer fibers that form in the photovoltaic blends with

  18. Effect of cadmium ions on dioxygen affinity and polyphosphate activity of human red blood cells.

    Science.gov (United States)

    Arkowitz, R; Gersonde, K

    1988-04-01

    The effect of cadmium ions on the dioxygen affinity, the time-dependent depletion of intracellular polyphosphates, and the elongation of human red blood cells (RBC's) was examined. The incubation of RBC's in the presence of 1 mM Cd2+ at 37 degrees C for more than one hour results in a decrease of the p50 value by 2.5-3.0 mmHg in comparison to controls. The p50 of stripped (phosphate-free) hemoglobin is not affected by the presence of 1 mM Cd2+ (p50 = 4.8 mmHg at pH 7.2 and 37 degrees C). Experiments with RBC cryolysates demonstrate an apparently competitive effect of 2.3-bisphosphoglycerate (DPG) with cadmium ions on the dioxygen affinity. From 31P NMR spectra, 31P T1 relaxation, and 31P T2 relaxation behavior a more direct evidence for DPG-Cd2+ complexation is obtained. 31P NMR spectra of RBC cryolysates also indicate DPG-Cd2+ complexation. The hydrolysis of free polyphosphates in RBC's incubated at 37 degrees C as monitored by 31P NMR spectra can be noticed after a three-hour lag phase (constant polyphosphate level). This lag phase is lengthened from three hours to four hours in the presence of Cd2+ ions. RBC elongation, as a measure of deformability, decreases slightly upon incubation with 1 mM Cd2+.

  19. Defect engineering in solar cell manufacturing and thin film solar cell development

    Energy Technology Data Exchange (ETDEWEB)

    Sopori, B.L. [National Renewable Energy Lab., Golden, CO (United States)

    1995-08-01

    During the last few years many defect engineering concepts were successfully applied to fabricate high efficiency silicon solar cells on low-cost substrates. Some of the research advances are described.

  20. How the relative permittivity of solar cell materials influences solar cell performance

    DEFF Research Database (Denmark)

    Crovetto, Andrea; Huss-Hansen, Mathias K.; Hansen, Ole

    2017-01-01

    The relative permittivity of the materials constituting heterojunction solar cells is usually not considered as a design parameter when searching for novel combinations of heterojunction materials. In this work, we investigate the validity of such an approach. Specifically, we show the effect...... of the materials permittivity on the physics and performance of the solar cell by means of numerical simulation supported by analytical relations. We demonstrate that, depending on the specific solar cell configuration and materials properties, there are scenarios where the relative permittivity has a major...... the heterojunction partner has a high permittivity, solar cells are consistently more robust against several non-idealities that are especially likely to occur in early-stage development, when the device is not yet optimized....

  1. Solar cell efficiency tables (version 48): Solar cell efficiency tables (version 48)

    Energy Technology Data Exchange (ETDEWEB)

    Green, Martin A. [Australian Centre for Advanced Photovoltaics, University of New South Wales, Sydney New South Wales 2052 Australia; Emery, Keith [National Renewable Energy Laboratory, 15013 Denver West Parkway Golden CO 80401 USA; Hishikawa, Yoshihiro [Research Center for Photovoltaics (RCPV), National Institute of Advanced Industrial Science and Technology (AIST), Central 2, Umezono 1-1-1 Tsukuba Ibaraki 305-8568 Japan; Warta, Wilhelm [Characterisation and Simulation/CalLab Cells, Fraunhofer Institute for Solar Energy Systems, Heidenhofstr. 2 D-79110 Freiburg Germany; Dunlop, Ewan D. [European Commission - Joint Research Centre, Renewable Energy Unit, Institute for Energy, Via E. Fermi 2749 IT-21027 Ispra VA Italy

    2016-06-17

    Consolidated tables showing an extensive listing of the highest independently confirmed efficiencies for solar cells and modules are presented. Guidelines for inclusion of results into these tables are outlined, and new entries since January 2016 are reviewed.

  2. Si based nanostructures for solar cells

    OpenAIRE

    Garozzo, Cristina Annamaria

    2011-01-01

    Photovoltaic technology has received increased attention as one of the most promising approach to carbon-free energy production. Bulk silicon cells, which convert between 14 and 17% of incident light into electricity, make up 90% of the solar cell market. Silicon is widely used because it is the second most abundant element in the earth's crust, and because the electronics industry has already developed infrastructure to process it. Yet the pricey and complicated manufacturing makes these pho...

  3. COMSAT's destructive physical analysis of aerospace nickel-cadmium cells for NASA/Goddard Space Flight Center

    Science.gov (United States)

    Robbins, Kathleen M. B.; Rao, Gopalakrishna M.; Yi, Thomas Y.

    1993-01-01

    Over the past 5 years, COMSAT has performed numerous destructive physical analyses (DPA's) on NASA-Goddard-supplied nickel-cadmium (Ni/Cd) cells. The samples included activated but uncycled cells, wet stored cells, cycled cells, and anomalous cells. The DPA's provided visual, morphological, and chemical analyses of the cell components. The DPA data for the analyzed cells are presented. For the cells investigated, the leading cause of poor performance, as determined by DPA, has been poor negative electrode utilization, which resulted in negative-electrode-limiting operation.

  4. Flexible thermal cycle test equipment for concentrator solar cells

    Science.gov (United States)

    Hebert, Peter H [Glendale, CA; Brandt, Randolph J [Palmdale, CA

    2012-06-19

    A system and method for performing thermal stress testing of photovoltaic solar cells is presented. The system and method allows rapid testing of photovoltaic solar cells under controllable thermal conditions. The system and method presents a means of rapidly applying thermal stresses to one or more photovoltaic solar cells in a consistent and repeatable manner.

  5. A Cost Roadmap for Silicon Heterojunction Solar Cells

    NARCIS (Netherlands)

    Louwen, A.|info:eu-repo/dai/nl/375268456; van Sark, W.G.J.H.M.|info:eu-repo/dai/nl/074628526; Schropp, Ruud; Faaij, A.

    Research and development of silicon heterojunction (SHJ) solar cells has seen a marked increase since the recent expiry of core patents describing SHJ technology. SHJ solar cells are expected to offer various cost benefits compared to conventional crystalline silicon solar cells. This paper analyses

  6. Modulation of the stress response during apoptosis and necrosis induction in cadmium-treated U-937 human promonocytic cells.

    Science.gov (United States)

    Galán, A; Troyano, A; Vilaboa, N E; Fernández, C; de Blas, E; Aller, P

    2001-02-05

    Treatment for 2 h with 200 microM cadmium chloride, followed by recovery, caused apoptosis and induced heat-shock protein 70 (HSP70) expression in U-937 promonocytic cells. However, pre-incubation with the GSH depleting agent L-buthionine-[S,R]-sulfoximine (BSO, 1 mM for 24 h) caused necrosis instead of apoptosis and failed to induce HSP70 expression. This failure was a consequence of necrosis instead of GSH depletion, since BSO allowed or even potentiated HSP70 induction when used in combination with heat shock (2 h at 42.5 degrees C) or with 50 microM cadmium, which caused apoptosis. The administration of N-acetyl-L-cysteine (NAC) at the beginning of recovery after BSO/200 microM cadmium treatment prevented the execution of necrosis and restored the execution of apoptosis, but did not restore HSP70 induction, indicating that the inhibition by BSO of HSP70 expression is an early regulated event. This contrasted with the capacity of NAC to prevent the alterations caused by BSO/200 microM cadmium in other proteins, namely the suppression of Bax expression and the increase in Bcl-2 and HSP-60 expression. Finally, it was observed that treatment with 200 microM cadmium rapidly increased the HSP70 mRNA level and stimulated heat-shock factor 1 (HSF1) trimerization and binding, and that these effects were prevented by pre-incubation with BSO. Taken together, these results indicate that the stress response is compatible with apoptosis but not with necrosis in cadmium-treated promonocytic cells. The suppression of the stress response is specifically due to the early inhibition of HSF1 activation.

  7. Review of Recent Progress in Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Fan-Tai Kong

    2007-01-01

    Full Text Available We introduced the structure and the principle of dye-sensitized solar cell (DSC. The latest results about the critical technology and the industrialization research on dye-sensitized solar cells were reviewed. The development of key components, including nanoporous semiconductor films, dye sensitizers, redox electrolyte, counter electrode, and conducting substrate in dye-sensitized solar cells was reviewed in detail. The developing progress and prospect of dye-sensitized solar cells from small cells in the laboratory to industrialization large-scale production were reviewed. At last, the future development of DSC was prospective for the tendency of dye-sensitized solar cells.

  8. Dynamic kirigami structures for integrated solar tracking.

    Science.gov (United States)

    Lamoureux, Aaron; Lee, Kyusang; Shlian, Matthew; Forrest, Stephen R; Shtein, Max

    2015-09-08

    Optical tracking is often combined with conventional flat panel solar cells to maximize electrical power generation over the course of a day. However, conventional trackers are complex and often require costly and cumbersome structural components to support system weight. Here we use kirigami (the art of paper cutting) to realize novel solar cells where tracking is integral to the structure at the substrate level. Specifically, an elegant cut pattern is made in thin-film gallium arsenide solar cells, which are then stretched to produce an array of tilted surface elements which can be controlled to within ±1°. We analyze the combined optical and mechanical properties of the tracking system, and demonstrate a mechanically robust system with optical tracking efficiencies matching conventional trackers. This design suggests a pathway towards enabling new applications for solar tracking, as well as inspiring a broader range of optoelectronic and mechanical devices.

  9. Enhancing Solar Cell Efficiencies through 1-D Nanostructures

    Directory of Open Access Journals (Sweden)

    Yu Kehan

    2008-01-01

    Full Text Available Abstract The current global energy problem can be attributed to insufficient fossil fuel supplies and excessive greenhouse gas emissions resulting from increasing fossil fuel consumption. The huge demand for clean energy potentially can be met by solar-to-electricity conversions. The large-scale use of solar energy is not occurring due to the high cost and inadequate efficiencies of existing solar cells. Nanostructured materials have offered new opportunities to design more efficient solar cells, particularly one-dimensional (1-D nanomaterials for enhancing solar cell efficiencies. These 1-D nanostructures, including nanotubes, nanowires, and nanorods, offer significant opportunities to improve efficiencies of solar cells by facilitating photon absorption, electron transport, and electron collection; however, tremendous challenges must be conquered before the large-scale commercialization of such cells. This review specifically focuses on the use of 1-D nanostructures for enhancing solar cell efficiencies. Other nanostructured solar cells or solar cells based on bulk materials are not covered in this review. Major topics addressed include dye-sensitized solar cells, quantum-dot-sensitized solar cells, and p-n junction solar cells.

  10. TRANSPARENT COATINGS FOR SOLAR CELLS RESEARCH

    Energy Technology Data Exchange (ETDEWEB)

    Glatkowski, P. J.; Landis, D. A.

    2013-04-16

    Todays solar cells are fabricated using metal oxide based transparent conductive coatings (TCC) or metal wires with optoelectronic performance exceeding that currently possible with Carbon Nanotube (CNT) based TCCs. The motivation for replacing current TCC is their inherent brittleness, high deposition cost, and high deposition temperatures; leading to reduced performance on thin substrates. With improved processing, application and characterization techniques Nanofiber and/or CNT based TCCs can overcome these shortcomings while offering the ability to be applied in atmospheric conditions using low cost coating processes At todays level of development, CNT based TCC are nearing commercial use in touch screens, some types of information displays (i.e. electronic paper), and certain military applications. However, the resistivity and transparency requirements for use in current commercial solar cells are more stringent than in many of these applications. Therefore, significant research on fundamental nanotube composition, dispersion and deposition are required to reach the required performance commanded by photovoltaic devices. The objective of this project was to research and develop transparent conductive coatings based on novel nanomaterial composite coatings, which comprise nanotubes, nanofibers, and other nanostructured materials along with binder materials. One objective was to show that these new nanomaterials perform at an electrical resistivity and optical transparency suitable for use in solar cells and other energy-related applications. A second objective was to generate new structures and chemistries with improved resistivity and transparency performance. The materials also included the binders and surface treatments that facilitate the utility of the electrically conductive portion of these composites in solar photovoltaic devices. Performance enhancement venues included: CNT purification and metallic tube separation techniques, chemical doping, CNT

  11. Solar Airplanes and Regenerative Fuel Cells

    Science.gov (United States)

    Bents, David J.

    2007-01-01

    A solar electric aircraft with the potential to "fly forever" has captured NASA's interest, and the concept for such an aircraft was pursued under Aeronautics Environmental Research Aircraft and Sensor Technology (ERAST) project. Feasibility of this aircraft happens to depend on the successful development of solar power technologies critical to NASA's Exploration Initiatives; hence, there was widespread interest throughout NASA to bring these technologies to a flight demonstration. The most critical is an energy storage system to sustain mission power during night periods. For the solar airplane, whose flight capability is already limited by the diffuse nature of solar flux and subject to latitude and time of year constraints, the feasibility of long endurance flight depends on a storage density figure of merit better than 400-600 watt-hr per kilogram. This figure of merit is beyond the capability of present day storage technologies (other than nuclear) but may be achievable in the hydrogen-oxygen regenerative fuel cell (RFC). This potential has led NASA to undertake the practical development of a hydrogen-oxygen regenerative fuel cell, initially as solar energy storage for a high altitude UAV science platform but eventually to serve as the primary power source for NASAs lunar base and other planet surface installations. Potentially the highest storage capacity and lowest weight of any non-nuclear device, a flight-weight RFC aboard a solar-electric aircraft that is flown continuously through several successive day-night cycles will provide the most convincing demonstration that this technology's widespread potential has been realized. In 1998 NASA began development of a closed cycle hydrogen oxygen PEM RFC under the Aeronautics Environmental Research Aircraft and Sensor Technology (ERAST) project and continued its development, originally for a solar electric airplane flight, through FY2005 under the Low Emissions Alternative Power (LEAP) project. Construction of

  12. Nanoparticles and nanoimaging for organic solar cells

    DEFF Research Database (Denmark)

    Pedersen, Emil Bøje Lind

    Solar energy is one of the few energy sources with the potential to power humanity in a future scenario where fossil fuels are not attractive due to their effect on the global climate or fossil fuels have been depleted all together. Organic photovoltaics is a promising technology for solar...... in photoactive Landfester nanoparticles. The dispersed particles are characterized by size, internal structure and crystallinity. Crystal orientation and spatial distribution of materials are quantified for cast layers of Landfester particles. A layer of particles is also investigated in a tandem solar cell...... and results in decreased angular displacements and increased spatial resolution. Further development of the algorithm could therefore be used to increase spatial resolution for characterization of organic photovoltaics and computed tomography in general....

  13. Proton irradiation effects of amorphous silicon solar cell for solar power satellite

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Yousuke; Oshima, Takeshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Sasaki, Susumu; Kuroda, Hideo; Ushirokawa, Akio

    1997-03-01

    Flexible amorphous silicon(fa-Si) solar cell module, a thin film type, is regarded as a realistic power generator for solar power satellite. The radiation resistance of fa-Si cells was investigated by the irradiations of 3,4 and 10 MeV protons. The hydrogen gas treatment of the irradiated fa-Si cells was also studied. The fa-Si cell shows high radiation resistance for proton irradiations, compared with a crystalline silicon solar cell. (author)

  14. High Aspect Ratio Semiconductor Heterojunction Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Redwing, Joan [Pennsylvania State Univ., University Park, PA (United States). Dept. of Material Science and Engineering; Mallouk, Tom [Pennsylvania State Univ., University Park, PA (United States). Dept. of Chemistry; Mayer, Theresa [Pennsylvania State Univ., University Park, PA (United States). Dept. of Electrical Engineering; Dickey, Elizabeth [Pennsylvania State Univ., University Park, PA (United States). Dept. of Materials Science and Engineering; Wronski, Chris [Pennsylvania State Univ., University Park, PA (United States). Dept. of Electrical Engineering

    2013-05-17

    The project focused on the development of high aspect ratio silicon heterojunction (HARSH) solar cells. The solar cells developed in this study consisted of high density vertical arrays of radial junction silicon microwires/pillars formed on Si substrates. Prior studies have demonstrated that vertical Si wire/pillar arrays enable reduced reflectivity and improved light trapping characteristics compared to planar solar cells. In addition, the radial junction structure offers the possibility of increased carrier collection in solar cells fabricated using material with short carrier diffusion lengths. However, the high junction and surface area of radial junction Si wire/pillar array devices can be problematic and lead to increased diode leakage and enhanced surface recombination. This study investigated the use of amorphous hydrogenated Si in the form of a heterojunction-intrinsic-thin layer (HIT) structure as a junction formation method for these devices. The HIT layer structure has widely been employed to reduce surface recombination in planar crystalline Si solar cells. Consequently, it was anticipated that it would also provide significant benefits to the performance of radial junction Si wire/pillar array devices. The overall goals of the project were to demonstrate a HARSH cell with a HIT-type structure in the radial junction Si wire/pillar array configuration and to develop potentially low cost pathways to fabricate these devices. Our studies demonstrated that the HIT structure lead to significant improvements in the open circuit voltage (Voc>0.5) of radial junction Si pillar array devices compared to devices fabricated using junctions formed by thermal diffusion or low pressure chemical vapor deposition (LPCVD). In addition, our work experimentally demonstrated that the radial junction structure lead to improvements in efficiency compared to comparable planar devices for devices fabricated using heavily doped Si that had reduced carrier diffusion

  15. Semiconductor Nanocrystals as Light Harvesters in Solar Cells

    Science.gov (United States)

    Etgar, Lioz

    2013-01-01

    Photovoltaic cells use semiconductors to convert sunlight into electrical current and are regarded as a key technology for a sustainable energy supply. Quantum dot-based solar cells have shown great potential as next generation, high performance, low-cost photovoltaics due to the outstanding optoelectronic properties of quantum dots and their multiple exciton generation (MEG) capability. This review focuses on QDs as light harvesters in solar cells, including different structures of QD-based solar cells, such as QD heterojunction solar cells, QD-Schottky solar cells, QD-sensitized solar cells and the recent development in organic-inorganic perovskite heterojunction solar cells. Mechanisms, procedures, advantages, disadvantages and the latest results obtained in the field are described. To summarize, a future perspective is offered. PMID:28809318

  16. Semiconductor Nanocrystals as Light Harvesters in Solar Cells

    Directory of Open Access Journals (Sweden)

    Lioz Etgar

    2013-02-01

    Full Text Available Photovoltaic cells use semiconductors to convert sunlight into electrical current and are regarded as a key technology for a sustainable energy supply. Quantum dot-based solar cells have shown great potential as next generation, high performance, low-cost photovoltaics due to the outstanding optoelectronic properties of quantum dots and their multiple exciton generation (MEG capability. This review focuses on QDs as light harvesters in solar cells, including different structures of QD-based solar cells, such as QD heterojunction solar cells, QD-Schottky solar cells, QD-sensitized solar cells and the recent development in organic-inorganic perovskite heterojunction solar cells. Mechanisms, procedures, advantages, disadvantages and the latest results obtained in the field are described. To summarize, a future perspective is offered.

  17. Semiconductor Nanocrystals as Light Harvesters in Solar Cells.

    Science.gov (United States)

    Etgar, Lioz

    2013-02-04

    Photovoltaic cells use semiconductors to convert sunlight into electrical current and are regarded as a key technology for a sustainable energy supply. Quantum dot-based solar cells have shown great potential as next generation, high performance, low-cost photovoltaics due to the outstanding optoelectronic properties of quantum dots and their multiple exciton generation (MEG) capability. This review focuses on QDs as light harvesters in solar cells, including different structures of QD-based solar cells, such as QD heterojunction solar cells, QD-Schottky solar cells, QD-sensitized solar cells and the recent development in organic-inorganic perovskite heterojunction solar cells. Mechanisms, procedures, advantages, disadvantages and the latest results obtained in the field are described. To summarize, a future perspective is offered.

  18. Pharmacologic modification of the cytotoxic effects of cadmium in LLC-PK sub 1 cells

    Energy Technology Data Exchange (ETDEWEB)

    Battaglia, D.R.; Kahan, B.S.; Niewenhuis, R.J.; Prozialeck, W.C. (Philadelphia College of Osteopathic Medicine, PA (USA))

    1989-02-09

    Recent results from our laboratories have shown that exposure to cadmium causes LLC-PK{sub 1} cells to shrink, detach and assume a spherical shape. The purpose of the present studies was to determine whether various pharmacologic agents can reduce or prevent these cytotoxic effects of Cd{sup 2+}. Confluent monolayers of LLC-PK{sub 1} cells were incubated with the drugs of interest (50 microM final concentration) for 2 hours. CadCl{sub 2} (final concentration = 75 microM) was then added and the cells were incubated for another 20 hours. Morphologic changes were assessed qualitatively by viewing the cells with a phase contrast microscope. The extent of Cd{sup 2+}-induced cellular damage was also quantified by staining the cells that remained on the growing surface with methylene blue, solubilizing the stained cells, and determining the absorbance at 660 nm. The results showed that several drugs, particularly the calmodulin antagonists trifluoperazine chlorpromazine, and the calcium channel blocker verapamil, significant reduced the severity of Cd{sup 2+}-induced cytotoxicity. By contrast, a variety of other agents, such as chlorpromazine sulfoxide, trifluoperazine sulfoxide, phenytoin and zinc, had no such protective effect. These findings indicate that Ca{sup 2+} antagonists can attenuate the cytotoxic effects of Cd{sup 2+} and that Cd{sup 2+} may produce some of its effects by activating Ca{sup 2+} -dependent systems.

  19. Rational Strategies for Efficient Perovskite Solar Cells.

    Science.gov (United States)

    Seo, Jangwon; Noh, Jun Hong; Seok, Sang Il

    2016-03-15

    A long-standing dream in the large scale application of solar energy conversion is the fabrication of solar cells with high-efficiency and long-term stability at low cost. The realization of such practical goals depends on the architecture, process and key materials because solar cells are typically constructed from multilayer heterostructures of light harvesters, with electron and hole transporting layers as a major component. Recently, inorganic-organic hybrid lead halide perovskites have attracted significant attention as light absorbers for the fabrication of low-cost and high-efficiency solar cells via a solution process. This mainly stems from long-range ambipolar charge transport properties, low exciton binding energies, and suitable band gap tuning by managing the chemical composition. In our pioneering work, a new photovoltaic platform for efficient perovskite solar cells (PSCs) was proposed, which yielded a high power conversion efficiency (PCE) of 12%. The platform consisted of a pillared architecture of a three-dimensional nanocomposite of perovskites fully infiltrating mesoporous TiO2, resulting in the formation of continuous phases and perovskite domains overlaid with a polymeric hole conductor. Since then, the PCE of our PSCs has been rapidly increased from 3% to over 20% certified efficiency. The unprecedented increase in the PCE can be attributed to the effective integration of the advantageous attributes of the refined bicontinuous architecture, deposition process, and composition of perovskite materials. Specifically, the bicontinuous architectures used in the high efficiency comprise a layer of perovskite sandwiched between mesoporous metal-oxide layer, which is a very thinner than that of used in conventional dye-sensitized solar cells, and hole-conducting contact materials with a metal back contact. The mesoporous scaffold can affect the hysteresis under different scan direction in measurements of PSCs. The hysteresis also greatly depends on

  20. Production technology for high efficiency ion implanted solar cells

    Science.gov (United States)

    Kirkpatrick, A. R.; Minnucci, J. A.; Greenwald, A. C.; Josephs, R. H.

    1978-01-01

    Ion implantation is being developed for high volume automated production of silicon solar cells. An implanter designed for solar cell processing and able to properly implant up to 300 4-inch wafers per hour is now operational. A machine to implant 180 sq m/hr of solar cell material has been designed. Implanted silicon solar cells with efficiencies exceeding 16% AM1 are now being produced and higher efficiencies are expected. Ion implantation and transient processing by pulsed electron beams are being integrated with electrostatic bonding to accomplish a simple method for large scale, low cost production of high efficiency solar cell arrays.

  1. Reciprocal Interactions between Cadmium-Induced Cell Wall Responses and Oxidative Stress in Plants

    Science.gov (United States)

    Loix, Christophe; Huybrechts, Michiel; Vangronsveld, Jaco; Gielen, Marijke; Keunen, Els; Cuypers, Ann

    2017-01-01

    Cadmium (Cd) pollution renders many soils across the world unsuited or unsafe for food- or feed-orientated agriculture. The main mechanism of Cd phytotoxicity is the induction of oxidative stress, amongst others through the depletion of glutathione. Oxidative stress can damage lipids, proteins, and nucleic acids, leading to growth inhibition or even cell death. The plant cell has a variety of tools to defend itself against Cd stress. First and foremost, cell walls might prevent Cd from entering and damaging the protoplast. Both the primary and secondary cell wall have an array of defensive mechanisms that can be adapted to cope with Cd. Pectin, which contains most of the negative charges within the primary cell wall, can sequester Cd very effectively. In the secondary cell wall, lignification can serve to immobilize Cd and create a tougher barrier for entry. Changes in cell wall composition are, however, dependent on nutrients and conversely might affect their uptake. Additionally, the role of ascorbate (AsA) as most important apoplastic antioxidant is of considerable interest, due to the fact that oxidative stress is a major mechanism underlying Cd toxicity, and that AsA biosynthesis shares several links with cell wall construction. In this review, modifications of the plant cell wall in response to Cd exposure are discussed. Focus lies on pectin in the primary cell wall, lignification in the secondary cell wall and the importance of AsA in the apoplast. Regarding lignification, we attempt to answer the question whether increased lignification is merely a consequence of Cd toxicity, or rather an elicited defense response. We propose a model for lignification as defense response, with a central role for hydrogen peroxide as substrate and signaling molecule. PMID:29163592

  2. Reciprocal Interactions between Cadmium-Induced Cell Wall Responses and Oxidative Stress in Plants

    Directory of Open Access Journals (Sweden)

    Christophe Loix

    2017-10-01

    Full Text Available Cadmium (Cd pollution renders many soils across the world unsuited or unsafe for food- or feed-orientated agriculture. The main mechanism of Cd phytotoxicity is the induction of oxidative stress, amongst others through the depletion of glutathione. Oxidative stress can damage lipids, proteins, and nucleic acids, leading to growth inhibition or even cell death. The plant cell has a variety of tools to defend itself against Cd stress. First and foremost, cell walls might prevent Cd from entering and damaging the protoplast. Both the primary and secondary cell wall have an array of defensive mechanisms that can be adapted to cope with Cd. Pectin, which contains most of the negative charges within the primary cell wall, can sequester Cd very effectively. In the secondary cell wall, lignification can serve to immobilize Cd and create a tougher barrier for entry. Changes in cell wall composition are, however, dependent on nutrients and conversely might affect their uptake. Additionally, the role of ascorbate (AsA as most important apoplastic antioxidant is of considerable interest, due to the fact that oxidative stress is a major mechanism underlying Cd toxicity, and that AsA biosynthesis shares several links with cell wall construction. In this review, modifications of the plant cell wall in response to Cd exposure are discussed. Focus lies on pectin in the primary cell wall, lignification in the secondary cell wall and the importance of AsA in the apoplast. Regarding lignification, we attempt to answer the question whether increased lignification is merely a consequence of Cd toxicity, or rather an elicited defense response. We propose a model for lignification as defense response, with a central role for hydrogen peroxide as substrate and signaling molecule.

  3. Cadmium activates CaMK-II and initiates CaMK-II-dependent apoptosis in mesangial cells.

    Science.gov (United States)

    Liu, Ying; Templeton, Douglas M

    2007-04-03

    Cadmium is a toxic metal that initiates both mitogenic responses and cell death. We show that Cd(2+) increases phosphorylation and activity of Ca(2+)/calmodulin-dependent protein kinase II (CaMK-II) in mesangial cells, in a concentration-dependent manner. Activation is biphasic with peaks at 1-5 min and 4-6 h. Cadmium also activates Erk, but this appears to be independent of CaMK-II. At 10-20 microM, Cd(2+) initiates apoptosis in 25-55% of mesangial cells by 6h. Inhibition of CaMK-II, but not of Erk, suppresses Cd(2+)-induced apoptosis. We conclude that activation of CaMK-II by Cd(2+) contributes to apoptotic cell death, independent of Erk activation.

  4. Photovoltaic characteristics of n(+)pp(+) InP solar cells grown by OMVPE

    Science.gov (United States)

    Tyagi, S.; Singh, K.; Bhimnathwala, H.; Ghandhi, S. K.; Borrego, J. M.

    1990-01-01

    The photovoltaic characteristics of n(+)/p/p(+) homojunction InP solar cells fabricated by organometallic vapor-phase epitaxy (OMVPE) are described. The cells are characterized by I-V, C-V and quantum efficiency measurements, and simulations are used to obtain various device and material parameters. The I-V characteristics show a high recombination rate in the depletion region; this is shown to be independent of the impurity used. It is shown that cadmium is easier to use as an acceptor for the p base and p(+) buffer and is therefore beneficial. The high quantum efficiency of 98 percent at long wavelengths measured in these cells indicates a very good collection efficiency in the base. The short-wavelength quantum efficiency is poor, indicating a high surface recombination.

  5. Kinetics of cadmium accumulation and its effects on microtubule integrity and cell viability in the seagrass Cymodocea nodosa

    Energy Technology Data Exchange (ETDEWEB)

    Malea, Paraskevi, E-mail: malea@bio.auth.gr [Department of Botany, School of Biology, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki (Greece); Adamakis, Ioannis-Dimosthenis S. [Department of Botany, School of Biology, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki (Greece); Kevrekidis, Theodoros [Laboratory of Environmental Research and Education, Democritus University of Thrace, Nea Hili, GR-68100 Alexandroupolis (Greece)

    2013-11-15

    Highlights: •Cd effect on microtubules and viability of seagrass leaf cells was assessed. •The Michaelis–Menten equation satisfactorily dercribed the kinetics of Cd uptake. •Cd depolymerized MTs after 3–9 d of exposure, cell death occurred at later time. •Toxicity appeared to depend on Cd uptake rate rather than on tissue Cd content. •MTs can be used as biomarker of Cd stress and uptake rate for predicting effects. -- Abstract: The kinetics of cadmium accumulation and its effects on microtubule cytoskeleton and cell viability in leaf blades of the seagrass Cymodocea nodosa were investigated under laboratory conditions in exposure concentrations ranging from 0.5 to 40 mg L{sup −1}. An initial rapid accumulation of cadmium was followed by a steady state. The Michaelis–Menten model adequately described metal accumulation; equilibrium concentration and uptake velocity tended to increase, whereas bioconcentration factor at equilibrium to decrease, as the exposure concentration increased. Cadmium depolymerized microtubules after 3–9 d of exposure, depending on trace metal concentration, indicating that microtubules could be used as an early biomarker of cadmium stress; cell death, occurring at later time than microtubule disturbance, was also observed. Microtubule depolymerization expressed as percentage of reduction of fluorescence intensity and cell mortality expressed as percentage of live cells increased with time. The lowest experimental tissue concentration associated with the onset of microtubule depolymerization and cell death (98.5–128.9 μg g{sup −1} dry wt, 0.5 mg L{sup −1} treatment, 7th and 9th d) was within the wide range of reported cadmium concentrations in leaves of seagrass species from various geographical areas. This lowest tissue concentration was exceeded up to the 3rd d at higher exposure concentrations, but toxic effects were generally detected at later time. The time periods required for the onset of depolymerization and

  6. Interface engineering of Graphene-Silicon heterojunction solar cells

    Science.gov (United States)

    Xu, Dikai; Yu, Xuegong; Yang, Lifei; Yang, Deren

    2016-11-01

    Graphene has attracted great research interests due to its unique mechanical, electrical and optical properties, which opens up a huge number of opportunities for applications. Recently, Graphene-Silicon (Grsbnd Si) solar cell has been recognized as one interesting candidate for the future photovoltaic. Since the first Grsbnd Si solar cell reported in 2010, Grsbnd Si solar cell has been intensively investigated and the power converse efficiency (PCE) of it has been developed to 15.6%. This review presents and discusses current development of Grsbnd Si solar cell. Firstly, the basic concept and mechanism of Grsbnd Si solar cell are introduced. Then, several key technologies are introduced to improve the performance of Grsbnd Si solar cells, such as chemical doping, annealing, Si surface passivation and interlayer insertion. Particular emphasis is placed on strategies for Grsbnd Si interface engineering. Finally, new pathways and opportunities of "MIS-like structure" Grsbnd Si solar cells are described.

  7. METHOD AND APPARATUS FOR CHARACTERIZATION OF A SOLAR CELL

    DEFF Research Database (Denmark)

    2017-01-01

    ; and estimating variations in the solar cell, thereby electrically characterizing the solar cell. The disclosure further relates to a solar cell characterization apparatus for characterization of a solar cell, comprising: a light source for generating an optical probe light; a modulation unit, configured......The present disclosure relates to a method for characterization of a solar cell, comprising the steps of: providing an optical probe light; modulating the optical probe light with a modulation frequency of between 100 kHz and 50 MHz, thereby obtaining a modulated probe light; scanning the modulated...... probe light such that said modulated probe light is incident on at least a part of the surface of the solar cell, and such that the part of the solar cell exposed to the modulated probe light converts the modulated probe light to an electrical signal; detecting and analyzing said electrical signal...

  8. Highly efficient light management for perovskite solar cells

    Science.gov (United States)

    Wang, Dong-Lin; Cui, Hui-Juan; Hou, Guo-Jiao; Zhu, Zhen-Gang; Yan, Qing-Bo; Su, Gang

    2016-01-01

    Organic-inorganic halide perovskite solar cells have enormous potential to impact the existing photovoltaic industry. As realizing a higher conversion efficiency of the solar cell is still the most crucial task, a great number of schemes were proposed to minimize the carrier loss by optimizing the electrical properties of the perovskite solar cells. Here, we focus on another significant aspect that is to minimize the light loss by optimizing the light management to gain a high efficiency for perovskite solar cells. In our scheme, the slotted and inverted prism structured SiO2 layers are adopted to trap more light into the solar cells, and a better transparent conducting oxide layer is employed to reduce the parasitic absorption. For such an implementation, the efficiency and the serviceable angle of the perovskite solar cell can be promoted impressively. This proposal would shed new light on developing the high-performance perovskite solar cells. PMID:26733112

  9. Highly efficient light management for perovskite solar cells

    CERN Document Server

    Wang, Dong-Lin; Hou, Guo-Jiao; Zhu, Zhen-Gang; Yan, Qing-Bo; Su, Gang

    2015-01-01

    Organic-inorganic halide perovskite solar cells have enormous potential to impact the existing photovoltaic industry. As realizing a higher conversion efficiency of the solar cell is still the most crucial task, a great number of schemes were proposed to minimize the carrier loss by optimizing the electrical properties of the perovskite solar cells. Here, we focus on another significant aspect that is to minimize the light loss by optimizing the light management to gain a high efficiency for perovskite solar cells. In our scheme, the slotted and inverted prism structured SiO2 layers are adopted to trap more light into the solar cells, and a better transparent conducting oxide layer is employed to reduce the parasitic absorption. For such an implementation, the efficiency and the serviceable angle of the perovskite solar cell can be promoted impressively. This proposal would shed new light on developing the high-performance perovskite solar cells.

  10. Highly efficient light management for perovskite solar cells

    Science.gov (United States)

    Wang, Dong-Lin; Cui, Hui-Juan; Hou, Guo-Jiao; Zhu, Zhen-Gang; Yan, Qing-Bo; Su, Gang

    2016-01-01

    Organic-inorganic halide perovskite solar cells have enormous potential to impact the existing photovoltaic industry. As realizing a higher conversion efficiency of the solar cell is still the most crucial task, a great number of schemes were proposed to minimize the carrier loss by optimizing the electrical properties of the perovskite solar cells. Here, we focus on another significant aspect that is to minimize the light loss by optimizing the light management to gain a high efficiency for perovskite solar cells. In our scheme, the slotted and inverted prism structured SiO2 layers are adopted to trap more light into the solar cells, and a better transparent conducting oxide layer is employed to reduce the parasitic absorption. For such an implementation, the efficiency and the serviceable angle of the perovskite solar cell can be promoted impressively. This proposal would shed new light on developing the high-performance perovskite solar cells.

  11. A hemicellulose-bound form of silicon inhibits cadmium ion uptake in rice (Oryza sativa) cells.

    Science.gov (United States)

    Ma, Jie; Cai, Hongmei; He, Congwu; Zhang, Wenjun; Wang, Lijun

    2015-05-01

    Silicon (Si) alleviates cadmium (Cd) toxicity in rice (Oryza sativa). However, the chemical mechanisms at the single-cell level are poorly understood. Here, a suspension of rice cells exposed to Cd and/or Si treatments was investigated using a combination of plant cell nutritional, molecular biological, and physical techniques including in situ noninvasive microtest technology (NMT), polymerase chain reaction (PCR), inductively coupled plasma mass spectroscopy (ICP-MS), and atomic force microscopy (AFM) in Kelvin probe mode (KPFM). We found that Si-accumulating cells had a significantly reduced net Cd(2+) influx, compared with that in Si-limited cells. PCR analyses of the expression levels of Cd and Si transporters in rice cells showed that, when the Si concentration in the medium was increased, expression of the Si transporter gene Low silicon rice 1 (Lsi1) was up-regulated, whereas expression of the gene encoding the transporter involved in the transport of Cd, Natural resistance-associated macrophage protein 5 (Nramp5), was down-regulated. ICP-MS results revealed that 64% of the total Si in the cell walls was bound to hemicellulose constituents following the fractionation of the cell walls, and consequently inhibited Cd uptake. Furthermore, AFM in KPFM demonstrated that the heterogeneity of the wall surface potential was higher in cells cultured in the presence of Si than in those cultured in its absence, and was homogenized after the addition of Cd. These results suggest that a hemicellulose-bound form of Si with net negative charges is responsible for inhibition of Cd uptake in rice cells by a mechanism of [Si-hemicellulose matrix]Cd complexation and subsequent co-deposition. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  12. Low-Stress interconnection of solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, I.J.; De Jong, P.C.; Kloos, M.J.H.; Stam, C.N.J. [ECN Solar Energy, P.O. Box 1, NL-1755 ZG Petten (Netherlands); Henckens, A.; Schuermans, J. [Emerson and Cuming, Nijverheidstraat 7, 2260 Westerlo (Belgium); Gomez, R.J. [BP Solar Spain, P. I. Tres Cantos, Zona Oeste, 28760 Tres Cantos, Madrid (Spain); Sanchez-Friera, P.; Lalaguna, B. [Isofoton, C/ Severo Ochoa 50, PTA, 29590 Malaga (Spain); Schmidt, H. [Solar World Industries Deutschland GmbH, Otto-Hahn-Ring 6, 81739 Muenchen (Germany)

    2007-08-15

    The suitability of a snap-curable acrylic-based conductive adhesive as a low-stress interconnection for thin solar cells was studied. Modules were manufactured using the conductive adhesive with industrial thin crystalline silicon solar cells. The best results were obtained for an adhesive with a high silver filler content. The adhesive resulted in a similar peel strength to a soldered interconnection. Although the contact resistance of the adhesive is much higher than for solder, it does not affect the module output power. Degradation in fill factor of only 2 % was measured after 1000 thermal shock cycles while no degradation was observed at all after 1000 hours damp-heat. Further testing on full-size modules to prove the suitability of the conductive adhesive in outdoor use is ongoing. Climate chamber test results of a direct comparison with soldered modules are presented.

  13. Modeling of Silicon Heterojunction Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Luppina, P.; Lugli, P.; Goodnick, S.

    2015-06-14

    Here we present modeling results on crystalline Si/amorphous Si (a-Si) heterojunction solar cells using Sentaurus including various models for defect states in the a-Si barriers, as well as explicit models for the ITO emitter contact. We investigate the impact of the band offsets and barrier heights of the a-Si/c-Si interface, particularly in terms of the open circuit voltage. It is also shown that the solar cell performance is sensitively dependent on the quality of the a-Si in terms of defect states and their distribution, particularly on the emitter side. Finally, we have investigate the role of tunneling and thermionic emission across the heterointerface in terms of transport from the Si to the ITO contact layer

  14. PLASMONIC NANOSTRUCTURES FOR ORGANIC SOLAR CELLS

    DEFF Research Database (Denmark)

    Mirsafaei, Mina

    2017-01-01

    Organic photovoltaics represent the third generation PV technology, and it is a technology that offers large cost reductions using inexpensive materials and low cost printing fabrication techniques such as roll-to-roll processing. The lower power conversion efficiencies of organic solar cells......, however, limit their viability and sustainability for cost competitive commercial production. Plasmonic assisted organic photovoltaics have a potential to increase the performance of devices and thus reduce the cost/kW of generating capacity. This is the motivation of the work presented in this doctoral...... thesis. Metallic nanostructures are used to enhance the light absorption within the semiconductor film in organic solar cells. A new lithography-free method for nanostructure formation from conjugated polymer is presented in this work. A highly concentrated polyethyleneglycol-capped gold nanoparticles...

  15. A Bicontinuous Double Gyroid Hybrid Solar Cell

    KAUST Repository

    Crossland, Edward J. W.

    2009-08-12

    We report the first successful application of an ordered bicontinuous gyroid semiconducting network in a hybrid bulk heterojunction solar cell. The freestanding gyroid network is fabricated by electrochemical deposition into the 10 nm wide voided channels of a self-assembled, selectively degradable block copolymer film. The highly ordered pore structure is ideal for uniform infiltration of an organic hole transporting material, and solid-state dye-sensitized solar cells only 400 nm thick exhibit up to 1.7% power conversion efficiency. This patterning technique can be readily extended to other promising heterojunction systems and is a major step toward realizing the full potential of self-assembly in the next generation of device technologies. © 2009 American Chemical Society.

  16. Perovskite Materials: Solar Cell and Optoelectronic Applications

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Bin [ORNL; Geohegan, David B [ORNL; Xiao, Kai [ORNL

    2017-01-01

    Hybrid organometallic trihalide perovskites are promising candidates in the applications for next-generation, high-performance, low-cost optoelectronic devices, including photovoltaics, light emitting diodes, and photodetectors. Particularly, the solar cells based on this type of materials have reached 22% lab scale power conversion efficiency in only about seven years, comparable to the other thin film photovoltaic technologies. Hybrid perovskite materials not only exhibit superior optoelectronic properties, but also show many interesting physical properties such as ion migration and defect physics, which may allow the exploration of more device functionalities. In this article, the fundamental understanding of the interrelationships between crystal structure, electronic structure, and material properties is discussed. Various chemical synthesis and processing methods for superior device performance in solar cells and optoelectronic devices are reviewed.

  17. Promises and challenges of perovskite solar cells

    Science.gov (United States)

    Correa-Baena, Juan-Pablo; Saliba, Michael; Buonassisi, Tonio; Grätzel, Michael; Abate, Antonio; Tress, Wolfgang; Hagfeldt, Anders

    2017-11-01

    The efficiencies of perovskite solar cells have gone from single digits to a certified 22.1% in a few years’ time. At this stage of their development, the key issues concern how to achieve further improvements in efficiency and long-term stability. We review recent developments in the quest to improve the current state of the art. Because photocurrents are near the theoretical maximum, our focus is on efforts to increase open-circuit voltage by means of improving charge-selective contacts and charge carrier lifetimes in perovskites via processes such as ion tailoring. The challenges associated with long-term perovskite solar cell device stability include the role of testing protocols, ionic movement affecting performance metrics over extended periods of time, and determination of the best ways to counteract degradation mechanisms.

  18. A thermodynamic cycle for the solar cell

    Science.gov (United States)

    Alicki, Robert; Gelbwaser-Klimovsky, David; Jenkins, Alejandro

    2017-03-01

    A solar cell is a heat engine, but textbook treatments are not wholly satisfactory from a thermodynamic standpoint, since they present solar cells as directly converting the energy of light into electricity, and the current in the circuit as maintained by an electrostatic potential. We propose a thermodynamic cycle in which the gas of electrons in the p phase serves as the working substance. The interface between the p and n phases acts as a self-oscillating piston that modulates the absorption of heat from the photons so that it may perform a net positive work during a complete cycle of its motion, in accordance with the laws of thermodynamics. We draw a simple hydrodynamical analogy between this model and the "putt-putt" engine of toy boats, in which the interface between the water's liquid and gas phases serves as the piston. We point out some testable consequences of this model.

  19. Low Doses of Cadmium Chloride and Methallothionein-1-Bound Cadmium Display Different Accumulation Kinetics and Induce Different Genes in Cells of the Human Nephron

    Directory of Open Access Journals (Sweden)

    Dana Cucu

    2011-08-01

    Full Text Available Background/Aims: The present study was conducted to investigate the renal tubular handling of inorganic cadmium (Cd2+ by exposing primary human tubular cell cultures to physiologically relevant doses of cadmium chloride (CdCl2. Furthermore, the cellular accumulation of Cd2+ was compared to that of metallothionein-1-bound Cd (Cd7MT-1. Finally, this study aimed to investigate the effect of the accumulation of Cd (both Cd2+ and Cd7MT-1 in renal cells on the expression of genes relevant to nephrotoxic processes. Methods: Cd concentration was measured using atomic absorption spectrometry. mRNA expression was evaluated by quantitative real-time RT-PCR. Results: Cd2+ accumulated into human tubular cells in a concentration- and time-dependent way. Furthermore, cellular accumulation of Cd2+ was different from the cellular accumulation of Cd7MT-1, indicative for different uptake routes. Finally, mRNA expression of the genes encoding the anti-oxidative proteins metallothionein-1 (MT-1 and heme-oxygenase-1 (HO-1 as well as the pro-apoptotic Bcl-2-associated X protein (Bax were upregulated by CdCl2 and not by Cd7MT1. Conclusion: In the presence of physiologically relevant Cd concentrations, tubular accumulation of the element in its inorganic form is different from that of Cd7MT-1. Furthermore, the tubular accumulation of inorganic Cd induces mRNA expression of genes of which the protein products may play a role in Cd-associated renal toxicity.

  20. Heme oxygenase-1-mediated autophagy protects against pulmonary endothelial cell death and development of emphysema in cadmium-treated mice.

    Science.gov (United States)

    Surolia, Ranu; Karki, Suman; Kim, Hyunki; Yu, Zhihong; Kulkarni, Tejaswini; Mirov, Sergey B; Carter, A Brent; Rowe, Steven M; Matalon, Sadis; Thannickal, Victor J; Agarwal, Anupam; Antony, Veena B

    2015-08-01

    Pulmonary exposure to cadmium, a major component of cigarette smoke, has a dramatic impact on lung function and the development of emphysema. Cigarette smoke exposure induces heme oxygenase-1 (HO-1), a cytoprotective enzyme. In this study, we employed a truncated mouse model of emphysema by intratracheal instillation of cadmium (CdCl2) solution (0.025% per 1 mg/kg body wt) in HO-1(+/+), HO-1(-/-), and overexpressing humanized HO-1 bacterial artificial chromosome (hHO-1BAC) mice. We evaluated the role of HO-1 in cadmium-induced emphysema in mice by analyzing histopathology, micro-computed tomography scans, and lung function tests. CdCl2-exposed HO-1(-/-) mice exhibited more severe emphysema compared with HO-1(+/+) or hHO-1BAC mice. Loss of pulmonary endothelial cells (PECs) from the alveolar capillary membrane is recognized to be a target in emphysema. PECs from HO-1(+/+), HO-1(-/-), and hHO-1BAC were employed to define the underlying molecular mechanism for the protection from emphysema by HO-1. Electron microscopy, expression of autophagic markers (microtubule-associated protein 1B-light chain 3 II, autophagy protein 5, and Beclin1) and apoptotic marker (cleaved caspase 3) suggested induction of autophagy and apoptosis in PECs after CdCl2 treatment. CdCl2-treated HO-1(-/-) PECs exhibited downregulation of autophagic markers and significantly increased cleaved caspase 3 expression and activity (∼4-fold higher). Moreover, hHO-1BAC PECs demonstrated upregulated autophagy and absence of cleaved caspase 3 expression or activity. Pretreatment of HO-1(+/+) PECs with rapamycin induced autophagy and resulted in reduced cell death upon cadmium treatment. Induction of autophagy following CdCl2 treatment was found to be protective from apoptotic cell death. HO-1 induced protective autophagy in PECs and mitigated cadmium-induced emphysema. Copyright © 2015 the American Physiological Society.

  1. Organic p-i-n solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Maennig, B.; Drechsel, J.; Gebeyehu, D.; Kozlowski, F.; Werner, A.; Li, F.; Grundmann, S.; Sonntag, S.; Koch, M.; Leo, K.; Pfeiffer, M. [Institut fuer Angewandte Photophysik, Technische Universitaet Dresden, 01062, Dresden (Germany); Simon, P. [Max Planck Institute for Chemical Physics of Solids, Dresden, 01187, Dresden (Germany); Hoppe, H.; Meissner, D.; Sariciftci, N.S. [Linz Institute for Organic Solar Cells (LIOS), Physical Chemistry, Johannes Kepler University, 4040, Linz (Austria); Riedel, I.; Dyakonov, V.; Parisi, J. [Energy and Semiconductor Research Laboratory, Institute of Physics, University of Oldenburg, 26111, Oldenburg (Germany)

    2004-06-01

    We introduce a p-i-n-type heterojunction architecture for organic solar cells where the active region is sandwiched between two doped wide-gap layers. The term p-i-n means here a layer sequence in the form p-doped layer, intrinsic layer and n-doped layer. The doping is realized by controlled co-evaporation using organic dopants and leads to conductivities of 10{sup -4} to 10{sup -5} S/cm in the p- and n-doped wide-gap layers, respectively. The photoactive layer is formed by a mixture of phthalocyanine zinc (ZnPc) and the fullerene C{sub 60} and shows mainly amorphous morphology. As a first step towards p-i-n structures, we show the advantage of using wide-gap layers in M-i-p-type diodes (metal layer-intrinsic layer-p-doped layer). The solar cells exhibit a maximum external quantum efficiency of 40% between 630-nm and 700-nm wavelength. With the help of an optical multilayer model, we optimize the optical properties of the solar cells by placing the active region at the maximum of the optical field distribution. The results of the model are largely confirmed by the experimental findings. For an optically optimized device, we find an internal quantum efficiency of around 82% under short-circuit conditions. Adding a layer of 10-nm thickness of the red material N,N'-dimethylperylene-3,4:9,10-dicarboximide (Me-PTCDI) to the active region, a power-conversion efficiency of 1.9% for a single cell is obtained. Such optically thin cells with high internal quantum efficiency are an important step towards high-efficiency tandem cells. First tandem cells which are not yet optimized already show 2.4% power-conversion efficiency under simulated AM 1.5 illumination of 125 mW/cm{sup 2}. (orig.)

  2. Polymer:fullerene bulk heterojunction solar cells

    OpenAIRE

    Nelson, Jenny

    2011-01-01

    The efficiency of solar cells made from a conjugated polymer blended with a fullerene derivative has risen from around 1 % to over 9 % in the last ten years, making organic photovoltaic technology a viable contender for commercialization. The efficiency increases have resulted from the development of new materials with lower optical gaps, new polymer:fullerene combinations with higher charge separated state energies, and new approaches to control the blend microstructure, all driven by a qual...

  3. Panchromatic Sequentially Cast Ternary Polymer Solar Cells.

    Science.gov (United States)

    Ghasemi, Masoud; Ye, Long; Zhang, Qianqian; Yan, Liang; Kim, Joo-Hyun; Awartani, Omar; You, Wei; Gadisa, Abay; Ade, Harald

    2017-01-01

    A sequential-casting ternary method is developed to create stratified bulk heterojunction (BHJ) solar cells, in which the two BHJ layers are spin cast sequentially without the need of adopting a middle electrode and orthogonal solvents. This method is found to be particularly useful for polymers that form a mechanically alloyed morphology due to the high degree of miscibility in the blend. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Plasmonic Dye-Sensitized Solar Cells

    KAUST Repository

    Ding, I-Kang

    2010-12-14

    This image presents a scanning electron microscopy image of solid state dye-sensitized solar cell with a plasmonic back reflector, overlaid with simulated field intensity plots when monochromatic light is incident on the device. Plasmonic back reflectors, which consist of 2D arrays of silver nanodomes, can enhance absorption through excitation of plasmonic modes and increased light scattering, as reported by Michael D. McGehee, Yi Cui, and co-workers.

  5. [Effect of cadmium on TET enzymes and DNA methylation changes in human embryonic kidney cell].

    Science.gov (United States)

    Li, Jinhui; Li, Wenxue; Yin, Hua; Zhang, Bo; Zhu, Wei

    2015-09-01

    To detect the expression changes of the demethylase TETs (Ten-eleven translocation enzymes) in human embryonic kidney cell (HEK293) exposed to high dose cadmium chloride (CdCl2), and to investigate the regulation effects of TETs on global genomic methylation. HEK293 cells were exposed to CdCl2 for 24 h, 48 h and 72 h, the survival rate was tested by CCK-8 (cell counting kit-8) method, and the cell morphology was observed. The levels of TETs mRNA and protein were detected by fluorescence quantitative PCR and Western blot, respectively. The genomic DNA methylation level was detectedby pyro sequencing assay. CdCl2 had toxic effects on HEK293 cells, and the half inhibitory concentration (IC50) was 1.78 µmol/L. After exposure of CdCl2 for 24 h, 48 h and 72 h, the morphology of HEK293 cells was altered, and the high dose group (2.0 µmol/L) showed vacuolar changes and fuzzy appearance. The level of TET1 mRNA in groups of 0.0, 0.5, 1.0, 2.0 µmol/L were 0.23 ± 0.13, 0.48 ± 0.12, 0.59 ± 0.16 and 0.95 ± 0.39, respectively (F = 182.89, P = 0.002); The level of TET2 mRNA in groups of 0.0, 0.5, 1.0, 2.0 µmol/L were 0.23 ± 0.12, 0.32 ± 0.02,0.31 ± 0.10 and 0.34 ± 0.07, respectively (F = 27.94, P trend as mRNA levels. In 24 h (55.01 ± 3.62)%, 48 h (48.31 ± 8.99)%, 72 h (48.76 ± 6.60)%, the DNA methylation had significant differences (F = 18.50, P trend of increase according to the exposure time and dose, and the methylation level of whole genomic DNA was also altered. The demethylase TETs may play a role in regulating the genomic methylation level of HEK293 exposed to cadmium.

  6. Target or barrier? The cell wall of early- and later- diverging plants vs cadmium toxicity: differences in the response mechanisms

    Directory of Open Access Journals (Sweden)

    Luigi eParrotta

    2015-03-01

    Full Text Available Increasing industrialization and urbanization result in emission of pollutants in the environment including toxic heavy metals, as cadmium and lead. Among the different heavy metals contaminating the environment, cadmium raises great concern, as it is ecotoxic and as such can heavily impact ecosystems. The cell wall is the first structure of plant cells to come in contact with heavy metals. Its composition, characterized by proteins, polysaccharides and in some instances lignin and other phenolic compounds, confers the ability to bind non-covalently and/or covalently heavy metals via functional groups. A strong body of evidence in the literature has shown the role of the cell wall in heavy metal response: it sequesters heavy metals, but at the same time its synthesis and composition can be severely affected. The present review analyzes the dual property of plant cell walls, i.e. barrier and target of heavy metals, by taking Cd toxicity as example. Following a summary of the known physiological and biochemical responses of plants to Cd, the review compares the wall-related mechanisms in early- and later-diverging land plants, by considering the diversity in cell wall composition. By doing so, common as well as unique response mechanisms to metal/cadmium toxicity are identified among plant phyla and discussed. After discussing the role of hyperaccumulators’ cell walls as a particular case, the review concludes by considering important aspects for plant engineering.

  7. PbSe Nanocrystal Excitonic Solar Cells

    KAUST Repository

    Choi, Joshua J.

    2009-11-11

    We report the design, fabrication, and characterization of colloidal PbSe nanocrystal (NC)-based photovoltaic test structures that exhibit an excitonic solar cell mechanism. Charge extraction from the NC active layer is driven by a photoinduced chemical potential energy gradient at the nanostructured heterojunction. By minimizing perturbation to PbSe NC energy levels and thereby gaining insight into the "intrinsic" photovoltaic properties and charge transfer mechanism of PbSe NC, we show a direct correlation between interfacial energy level offsets and photovoltaic device performance. Size dependent PbSe NC energy levels were determined by cyclic voltammetry and optical spectroscopy and correlated to photovoltaic measurements. Photovoltaic test structures were fabricated from PbSe NC films sandwiched between layers of ZnO nanoparticles and PEDOT:PSS as electron and hole transporting elements, respectively. The device current-voltage characteristics suggest a charge separation mechanism that Is distinct from previously reported Schottky devices and consistent with signatures of excitonic solar cells. Remarkably, despite the limitation of planar junction structure, and without film thickness optimization, the best performing device shows a 1-sun power conversion efficiency of 3.4%, ranking among the highest performing NC-based solar cells reported to date. © 2009 American Chemical Society.

  8. Oxide nanowires for solar cell applications.

    Science.gov (United States)

    Zhang, Qifeng; Yodyingyong, Supan; Xi, Junting; Myers, Daniel; Cao, Guozhong

    2012-03-07

    Oxide nanowire arrays were studied for their applications to solar cells. It was demonstrated that the nanowires could provide direct pathways for electron transport in dye-sensitized solar cells and therefore, while forming photoelectrode films, they offered better suppression of charge recombination than nanoparticles. However, the photoelectron films consisting of nanowires suffered a disadvantage in giving large surface area for dye adsorption. Such a shortcoming of nanowires had been exemplified in this paper illustrating that it could be well compensated by incorporating with nanoparticles to form a nanoparticle-nanowire array hybrid photoelectrode film. The oxide nanowires were also demonstrated to be able to enhance the performance of inverted structure polymer solar cells as a cathode buffer layer by establishing a large interface with the polymers so as to facilitate the transport of photogenerated electrons from the polymer to the electron collecting electrode. Such an enhancement effect could be further boosted while the nanowires were replaced with nanotubes; the latter may build up larger interface with the polymers than the former and therefore facilitates the electron transport more efficiently.

  9. Solar-hydrogen fuel-cell vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Deluchi, M.A. (California Univ., Davis, CA (United States). Inst. of Transportation Studies); Ogden, J.M. (Princeton Univ., NJ (United States). Center for Energy and Environmental Studies)

    1993-05-01

    A fuel cycle in which hydrogen is produced by solar-electrolysis of water, or by gasification of renewable grown biomass, and then used in a fuel-cell powered electric-motor vehicle (FCEV), would produce little or no local, regional or global pollution. Hydrogen FCEVs would combine the best features of battery-powered electric vehicles (BPEVS) - zero emissions, high efficiency, quiet operation and long life -with the long range and fast refueling time of internal-combustion-engine vehicles (ICEVs). If fuel-cell technology develops as hoped, then hydrogen FCEVs will be a significant advance over both hydrogen ICEVs and solar BPEVs: they will be cleaner and more efficient than hydrogen ICEVs, have a much shorter refueling time than BPEVs and have a lower life-cycle cost than both. Solar-hydrogen fuel-cell vehicles would be general-purpose zero-emission vehicles, and could be an important component of a strategy for reducing dependence on imported oil, mitigating global warming and improving urban air quality, at an acceptable cost. (author)

  10. Surface magnetism of gallium arsenide nanofilms

    OpenAIRE

    Lu, Huan; Yu, Jin; Guo, Wanlin

    2017-01-01

    Gallium arsenide (GaAs) is the widest used second generation semiconductor with a direct band gap and increasingly used as nanofilms. However, the magnetic properties of GaAs nanofilms have never been studied. Here we find by comprehensive density functional theory calculations that GaAs nanofilms cleaved along the and directions become intrinsically metallic films with strong surface magnetism and magnetoelectric (ME) effect. The surface magnetism and electrical conductivity are realized v...

  11. Laser scanning of experimental solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Plunkett, B.C.; Lasswell, P.G.

    1980-01-01

    An instrument is described which measures and displays the response of the solar cell to a precisely positioned spot of HeNe laser light. By scanning the spot across the cell surface, one can create a map of the spatial variation in response of the cell. This map allows one to isolate flaws in cell contact integrity, locate open top surface grid lines, and evaluate fundamental junction performance. The system is useful for identifying and locating changes in the cell as it progresses through various experiments (e.g. stability studies). The laser scanner system is designed to be flexible and can accommodate different types of solar cell materials and a wide range of spot and scan sizes. Several modes of operation of the equipment are described, and results from two photovoltaic materials (CdS/Cu/sub 2/S and Zn/sub 3/P/sub 2/) are presented which demonstrate the capabilities of the system. Finally some of the proposed future uses of the system are discussed. 6 refs.

  12. Adipose Tissue-Derived Stem Cell Imaging Using Cadmium-Free Quantum Dots

    Science.gov (United States)

    Miyazaki, Yoshiyuki; Yukawa, Hiroshi; Nishi, Hiroyasu; Okamoto, Yukihiro; Kaji, Noritada; Torimoto, Tsukasa; Baba, Yoshinobu

    2013-01-01

    Quantum dots (QDs) have received much attention for biomolecule and cell imaging applications because of their superior optical properties such as high quantum efficiency, size-tunable emission, and resistance to photobleaching process. However, QDs that are commercially available contain cadmium (Cd), a highly toxic element. Thus, the development of Cd-free and less toxic QDs is strongly desired. In this study, we developed Cd-free QDs (ZnS-coated ZnS-AgInS2 solid solution nanoparticles with a sulfo group: ZnS-ZAIS-SO3H) and investigated the ability of this material to label stem cells. ZnS-ZAIS-SO3H could be transduced into mouse adipose tissue-derived stem cells (mASCs) using octaarginine peptides (R8), known as cell-penetrating peptides. The optimal ratio of ZnS-ZAIS-SO3H:R8 was found to be 1:100 for labeling mASCs. More than 80% of mASCs labeled with 500 nM ZnS-ZAIS-SO3H were found to be alive, and the proliferation rates of labeled mASCs were maintained at the same rate as that of nonlabeled mASCs. In addition, no abnormalities in the morphology of mASCs labeled with ZnS-ZAIS-SO3H could be observed. These data suggest that ZnS-ZAIS-SO3H may be effective for the labeling of mASCs. PMID:26858885

  13. Adipose Tissue-Derived Stem Cell Imaging Using Cadmium-Free Quantum Dots.

    Science.gov (United States)

    Miyazaki, Yoshiyuki; Yukawa, Hiroshi; Nishi, Hiroyasu; Okamoto, Yukihiro; Kaji, Noritada; Torimoto, Tsukasa; Baba, Yoshinobu

    2013-12-30

    Quantum dots (QDs) have received much attention for biomolecule and cell imaging applications because of their superior optical properties such as high quantum efficiency, size-tunable emission, and resistance to photobleaching process. However, QDs that are commercially available contain cadmium (Cd), a highly toxic element. Thus, the development of Cd-free and less toxic QDs is strongly desired. In this study, we developed Cd-free QDs (ZnS-coated ZnS-AgInS2 solid solution nanoparticles with a sulfo group: ZnS-ZAIS-SO3H) and investigated the ability of this material to label stem cells. ZnS-ZAIS-SO3H could be transduced into mouse adipose tissue-derived stem cells (mASCs) using octaarginine peptides (R8), known as cell-penetrating peptides. The optimal ratio of ZnS-ZAIS-SO3H:R8 was found to be 1:100 for labeling mASCs. More than 80% of mASCs labeled with 500 nM ZnS-ZAIS-SO3H were found to be alive, and the proliferation rates of labeled mASCs were maintained at the same rate as that of nonlabeled mASCs. In addition, no abnormalities in the morphology of mASCs labeled with ZnS-ZAIS-SO3H could be observed. These data suggest that ZnS-ZAIS-SO3H may be effective for the labeling of mASCs.

  14. Historic Developments, Current Technologies and Potential of Nanotechnology to Develop Next Generation Solar Cells with Improved Efficiency

    Directory of Open Access Journals (Sweden)

    Nisith Raval

    2015-07-01

    Full Text Available Sun is the continuous source of renewable energy, from where we can get abundant of solar energy. Concept of conversionof solar energy into heat was used back in 200 B.C. since then, the solar cells have been developed which can convert solar energy into theelectrical energy and these systems have been produced commercially. The technologies to enhance the power conversion efficiency (PCEhave been continuously improved. Different technologies used for developing solar cells can be categorized either on the basis of materialused or techniques of technology development which is further termed as ‘first generation’ (e.g. crystalline silicon, ‘second generation’(thin films of Amorphous silicon, Copper indium gallium selenide, Cadmium telluride, ‘Third generation’ (Concentrated, Organic and Dyesensitize solar cell. These technologies give PCE up to 25% depending on the technology and the materials used. Nanotechnology enablesthe use of nanomaterial whose size is below 100 nm with extraordinary properties which has the capability to enhance the PCE to greaterextent. Various nanomaterials like Quantum Dots, Quantum well, carbon nanotubes, Nanowire and graphene have been used to makeefficient and economical solar cells, which not only provide high conversion efficiency economically but also are easy to produce. Today,by using nanotechnology, conversion efficiency up to 44.7 % has been achieved by Fraunhofer Institute at Germany. In this review article,we have reviewed the literature including various patents and publications, summarized the history of solar cell development, developmentof different technologies and rationale of their development highlighting the advantages and challenges involved in their development forcommercial purpose. We have also included the recent developments in solar cell research where different nanomaterials have beendesigned and used successfully to prove their superiority over conventional systems.

  15. A novel three-jet microreactor for localized metal-organic chemical vapour deposition of gallium arsenide: design and simulation

    Science.gov (United States)

    Konakov, S. A.; Krzhizhanovskaya, V. V.

    2016-08-01

    We present a novel three-jet microreactor design for localized deposition of gallium arsenide (GaAs) by low-pressure Metal-Organic Chemical Vapour Deposition (MOCVD) for semiconductor devices, microelectronics and solar cells. Our approach is advantageous compared to the standard lithography and etching technology, since it preserves the nanostructure of the deposited material, it is less time-consuming and less expensive. We designed two versions of reactor geometry with a 10-micron central microchannel for precursor supply and with two side jets of a dilutant to control the deposition area. To aid future experiments, we performed computational modeling of a simplified-geometry (twodimensional axisymmetric) microreactor, based on Navier-Stokes equations for a laminar flow of chemically reacting gas mixture of Ga(CH3)3-AsH3-H2. Simulation results show that we can achieve a high-rate deposition (over 0.3 μm/min) on a small area (less than 30 μm diameter). This technology can be used in material production for microelectronics, optoelectronics, photovoltaics, solar cells, etc.

  16. Semitransparent organic solar cells with organic wavelength dependent reflectors

    NARCIS (Netherlands)

    Galagan, Y.O.; Debije, M.G.; Blom, P.W.M.

    2011-01-01

    Semitransparent organic solar cells employing solution-processable organic wavelength dependent reflectors of chiral nematic (cholesteric) liquid crystals are demonstrated. The cholesteric liquid crystal (CLC) reflects only in a narrow band of the solar spectrum and remains transparent for the

  17. Solar energy powered microbial fuel cell with a reversible bioelectrode

    NARCIS (Netherlands)

    Strik, D.P.B.T.B.; Hamelers, H.V.M.; Buisman, C.J.N.

    2010-01-01

    The solar energy powered microbial fuel cell is an emerging technology for electricity generation via electrochemically active microorganisms fueled by solar energy via in situ photosynthesized metabolites from algae, cyanobacteria, or living higher plants. A general problem with microbial fuel

  18. Performance evaluation of hybrid modified micro-channel solar cell ...

    African Journals Online (AJOL)

    user

    Keywords: Solar cell thermal tile, Micro-channel, Electrical efficiency, Thermal modeling. 1. ... performance of building integrated photovoltaic water –heating system for ... experimental study on energy generation with a photovoltaic (PV) solar ...

  19. Microstructured extremely thin absorber solar cells

    DEFF Research Database (Denmark)

    Biancardo, Matteo; Krebs, Frederik C

    2007-01-01

    In this paper we present the realization of extremely thin absorber (ETA) solar cells employing conductive glass substrates functionalized with TiO2 microstructures produced by embossing. Nanocrystalline or compact TiO2 films on Indium doped tin oxide (ITO) glass substrates were embossed...... by pressing a silicon stamp containing a mu m size raised grid structure into the TiO2 by use of a hydraulic press (1 ton/50 cm(2)). The performance of these microstructured substrates in a ETA cell sensitized by a thermally evaporated or chemical bath deposited PbS film and completed by a PEDOT:PSS hole...

  20. Electrolyte management considerations in modern nickel hydrogen and nickel cadmium cell and battery designs

    Science.gov (United States)

    Thaller, L. H.; Zimmerman, A. H.

    1995-04-01

    In the early 1980's the NASA Lewis group addressed the topic of designing nickel hydrogen cells for LEO applications. As published in 1984, the design addressed the topics of gas management, liquid management, plate expansion, and the recombination of oxygen during overcharge. This design effort followed principles set forth in an earlier Lewis paper that addressed the topic of pore size engineering. At about that same time, the beneficial effect on cycle life of lower electrolyte concentrations was verified by Hughes Aircraft as part of a Lewis funded study. A succession of life cycle tests of these concepts have been carried out that essentially verified all of this earlier work. During these past two decades, some of the mysteries involved in the active material of the nickel electrode have been resolved by careful research efforts carried out at several laboratories. At The Aerospace Corporation, Dr. Zimmerman has been developing a sophisticated model of an operating nickel hydrogen cell which will be used to model certain mechanisms that have contributed to premature failures in nickel hydrogen and nickel cadmium cells. During the course of trying to understand and model abnormal nickel hydrogen cell behaviors, we have noted that not enough attention has been paid to the potassium ion content in these cells, and more recently batteries. Several of these phenomenon have been well known in the area of alkaline fuel cells, but only recently have they been examined as they might impact alkaline cell designs. This paper will review three general areas where the potassium ion content can impact the performance and life of nickel hydrogen and nickel cadmium devices, Once these phenomenon are understood conceptually, the impact of potassium content on a potential cell design can be evaluated with the aid of an accurate model of an operating cell or battery. All three of these areas are directly related to the volume tolerance and pore size engineering aspects of the

  1. The growth inhibitory effects of cadmium and copper on the MDA-MB468 human breast cancer cells

    Directory of Open Access Journals (Sweden)

    Mojtaba Panjehpour

    2010-01-01

    Full Text Available Background: Cadmium chloride is an important occupational and environmental pollutant. However, it can also be anti-carcinogenic under certain conditions. Copper, an essential trace element, has the ability to generate reactive oxygen species and induce cell apoptosis. This study was aimed to determine the growth inhibitory effects of cadmium and copper on the MDA-MB468 human breast cancer cells. Methods: By using MTT cell viability test, treatment of monolayer cell cultures with different metal concentrations (1-1000 μM showed a significant dose dependent decrease (p < 0.05 of viable cells in different times. Results: A considerable cytotoxicity was observed for CdCl2 at 200 μM and 1 μM after 48 and 72 hours incubations, respectively. The highest concentration of CuCl2 (1000 μM had little cytotoxic effects after 48 hours incubation period, but 1 μM of CuCl2 revealed a considerable cytotoxicity after 72 hours. The maximum synergic cytotoxic effect was observed at 0.5 μM of both metals. Conclusions: The results of the present study indicate that cytotoxic effect of CuCl2 is somehow lesser than that of CdCl2. This may be due to vital role of copper which is not known for cadmium so far.

  2. Characterization of cadmium transport in hepatopancreatic cells of a mangrove crab Ucides cordatus: The role of calcium.

    Science.gov (United States)

    Ortega, Priscila; Custódio, Marcio R; Zanotto, Flavia P

    2017-07-01

    Cadmium is a toxic metal, present in batteries and discarded in estuaries and mangrove habitats. Apart from that, it is a non-essential metal that causes toxic effects in many organisms. Cadmium accumulates in gills and hepatopancreas of crustaceans and its route into the cell is unknown. It is possible that occurs by calcium channels or calcium transporters. The objective of this study was to characterize the transport of cadmium and the role of calcium in different cell types from hepatopancreas of the mangrove crab Ucides cordatus. For this, the hepatopancreas was dissociated by magnetic stirring and after that separated by a sucrose gradient. Then, the cells were labeled with FluoZin-3 AM and different CdCl2 concentrations were added together with a variety of inhibitors. The results showed that Cd(2+) transport occurs differently in each cell type from hepatopancreas and is partially explained by the function the cells perform in this organ. Embryonic (E) and Resorptive (R) cells transported more Cd(2+) compared to Fibrillar (F) and Blister (B) cells. R cells responded to Ca(2+) channel inhibitors and intracellular Ca(2+) manipulations positively, as the other cell types and in a stronger way. B cells were the least responsive to Ca(2+) channel inhibitors and, unlike the other cells, showed a competition of Cd(2+) with intracellular Ca(2+) manipulations. The results indicate that Ca(2+) affects the transport of Cd(2+) in hepatopancreatic cells of Ucides cordatus and uses Ca(2+) channels to enter these cells. In addition, information about Ca concentration could be used as a mitigating factor for Cd accumulation in crabs' hepatopancreas. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Five-Junction Solar Cell Optimization Using Silvaco Atlas

    Science.gov (United States)

    2017-09-01

    cell design by Fraunhofer ISE to provide the baseline structure for a simulation model based on published cell characteristics. This structure is...devices, which offer significant improvements over conventional single-junction solar cell designs . This research uses an existing five-junction solar...and maximize efficiency. Optimization of solar cell efficiency is carried out via nearly orthogonal balanced design of experiments methodology. Silvaco

  4. High performance organic solar cell architectures

    Science.gov (United States)

    Inoue, Kanzan

    This research is dedicated to the study of physical processes in solar cells based on organic polymers and small molecules, which may replace fossil-fuel based energy sources in future. The bulk of this research involves (1) improving charge generation and collection in well known bulk heterojunction polymer/fullerene-based devices via creating a percolating interpenetrating networks for further efficiency improvement, (2) developing new device architectures for multi-junction organic photovoltaics, and (3) developing new methods for encapsulation of organic solar cells by multilayer coatings. For bulk heterojunction Regio Regular P3HT/PCBM-based devices, the importance of pre-production and optimum post-production heat treatment conditions have been studied for different P3HT molecular weights and a record-breaking power conversion efficiency near 4% was achieved. This effect is partially achieved because annealing induces better crystalinity and hence increases the charge mobility in Regio Regular P3HT and initiates a diffusion controlled formation of PCBM network. This is reflected in the improvement of Fill Factor. The importance of pre-production to create a fine homogenization was discovered in this project. The novel electron and hole blocking layers deployed bulk heterojunction devices have been developed and the further improvement in the charge collection efficiency and fill factor were observed. Combining the P3HT/PCBM-based back cell with small organic molecular front cell, a new spectrally asymmetric multi-junction tandem device prototype has been created. With this device, wide range of solar spectra can be observed and open-circuit voltage greater than 1V can be routinely achieved, compared to 0.5--0.6V in conventional one layer devices. Purely polymeric tandem cell has also been tested. Such devices have a great prospect of low cost mass production.

  5. Defect behavior of polycrystalline solar cell silicon

    Energy Technology Data Exchange (ETDEWEB)

    Schroder, D.K.; Park, S.H.; Hwang, I.G.; Mohr, J.B.; Hanly, M.P. [Arizona State Univ., Tempe, AZ (US). Center for Solid State Electronics Research

    1993-05-01

    The major objective of this study, conducted from October 1988 to September 1991, was to gain an understanding of the behavior of impurities in polycrystalline silicon and the influence of these impurities on solar cell efficiency. The authors studied edge-defined film-fed growth (EFG) and cast poly-Si materials and solar cells. With EFG Si they concentrated on chromium-doped materials and cells to determine the role of Cr on solar cell performance. Cast poly-Si samples were not deliberately contaminated. Samples were characterized by cell efficiency, current-voltage, deep-level transient spectroscopy (DLTS), surface photovoltage (SPV), open-circuit voltage decay, secondary ion mass spectrometry, and Fourier transform infrared spectroscopy measurements. They find that Cr forms Cr-B pairs with boron at room temperature and these pairs dissociate into Cr{sub i}{sup +} and B{sup {minus}} during anneals at 210{degrees}C for 10 min. Following the anneal, Cr-B pairs reform at room temperature with a time constant of 230 h. Chromium forms CrSi{sub 2} precipitates in heavily contaminated regions and they find evidence of CrSi{sub 2} gettering, but a lack of chromium segregation or precipitation to grain boundaries and dislocations. Cr-B pairs have well defined DLTS peaks. However, DLTS spectra of other defects are not well defined, giving broad peaks indicative of defects with a range of energy levels in the band gap. In some high-stress, low-efficiency cast poly-Si they detect SiC precipitates, but not in low-stress, high-efficiency samples. SPV measurements result in nonlinear SPV curves in some materials that are likely due to varying optical absorption coefficients due to locally varying stress in the material.

  6. Materials That Enhance Efficiency and Radiation Resistance of Solar Cells

    Science.gov (United States)

    Sun, Xiadong; Wang, Haorong

    2012-01-01

    A thin layer (approximately 10 microns) of a novel "transparent" fluorescent material is applied to existing solar cells or modules to effectively block and convert UV light, or other lower solar response waveband of solar radiation, to visible or IR light that can be more efficiently used by solar cells for additional photocurrent. Meanwhile, the layer of fluorescent coating material remains fully "transparent" to the visible and IR waveband of solar radiation, resulting in a net gain of solar cell efficiency. This innovation alters the effective solar spectral power distribution to which an existing cell gets exposed, and matches the maximum photovoltaic (PV) response of existing cells. By shifting a low PV response waveband (e.g., UV) of solar radiation to a high PV response waveband (e.g. Vis-Near IR) with novel fluorescent materials that are transparent to other solar-cell sensitive wavebands, electrical output from solar cells will be enhanced. This approach enhances the efficiency of solar cells by converting UV and high-energy particles in space that would otherwise be wasted to visible/IR light. This innovation is a generic technique that can be readily implemented to significantly increase efficiencies of both space and terrestrial solar cells, without incurring much cost, thus bringing a broad base of economical, social, and environmental benefits. The key to this approach is that the "fluorescent" material must be very efficient, and cannot block or attenuate the "desirable" and unconverted" waveband of solar radiation (e.g. Vis-NIR) from reaching the cells. Some nano-phosphors and novel organometallic complex materials have been identified that enhance the energy efficiency on some state-of-the-art commercial silicon and thin-film-based solar cells by over 6%.

  7. Organization of amplified metallothionein (MT) genes in cadmium-resistant Chinese hamster cells

    Energy Technology Data Exchange (ETDEWEB)

    Hildebrand, C.; Grady, D.; Meincke, L.; Clark, L.; Qui, X.; Fehrenbach, S.; Brown, N.; Jones, M.; Longmire, J.; Moyzis, R.

    1987-05-01

    In the parental, cadmium-sensitive, CHO cells, two MT genes (MT-I and II) have been cloned and shown to encompass approx.9 Kb of DNA. Both genes demonstrate the canonical intron-exon organization observed for other mammalian MT genes. Chromosome walking has been employed to study the organization of the MT genes in amplified cell lines. Using DNA from a highly-amplified cell line, Cd/sup r/ 200 T1, a genomic library was constructed in lambda Ch35 by standard procedures. Recombinants containing sequences complementary to a MT-II cDNA probe were isolated and characterized. Restriction enzyme analyses of these recombinants have extended the map of the MT-I and II gene region to encompass approx.35 Kb of DNA and indicate stability of the amplified genome over this region. A single SacII restriction site has been identified at the extreme 3' end of the cloned region. Since SacII is an infrequently-cutting restriction enzyme, accelerated long-range restriction mapping of the amplified MT gene region will be possible by combining chromosome walking in the MT gene region with large fragment separation using field-in-version gel electrophoresis.

  8. N-acetylcysteine effectively mitigates cadmium-induced oxidative damage and cell death in Leydig cells in vitro.

    Science.gov (United States)

    Khanna, Smita; Mitra, Sumonto; Lakhera, Pramesh C; Khandelwal, Shashi

    2016-01-01

    Cadmium (Cd) is known to cause severe damage to various organs including lung, liver, kidney, brain and reproductive system. Several studies have reported the induction of oxidative stress pathways following Cd exposure. Since oxidative stress is also deemed responsible for inducing male infertility, a growing worldwide concern, we tried to understand whether the antioxidant N-acetylcysteine (NAC) can be a potential therapeutic agent to counter Cd toxicity using primary Leydig cells. This study highlights the initial cellular alterations which culminate in cell death induction. Primary Leydig cells were isolated from 28-day-old male Wistar rats, exposed to various concentrations of Cd in vitro and biochemical and cell death parameters were evaluated to understand the effect of Cd. NAC pre-treatment was done to understand its protective efficacy. Following Cd exposure to Leydig cells in vitro, we found simultaneous intracellular calcium (Ca(2+)) increase and reduction in mitochondrial membrane polarization at 30 min, followed by significant induction of reactive oxygen species and MAPK-extracellular-regulated kinases with concurrent glutathione depletion at 1 h, and significant cell death (both necrotic and apoptotic) at 6 and 18 h, respectively. Pre-treatment with NAC abrogated all these toxic manifestations and showed significantly reduced cell death. NAC also rescued the expression of 3-βHSD, a major steroidogenic protein. Taken together, these data illustrated that NAC can be used as a potential protective agent against Cd-induced testicular toxicity, especially with regards to oxidative stress-induced Leydig cell toxicity.

  9. Organic Solar Cells: Problems and Perspectives

    Directory of Open Access Journals (Sweden)

    G. Chidichimo

    2010-01-01

    Full Text Available For photovoltaic cells to convert solar into electric energy is probably the most interesting research challenge nowadays. A good efficiency of these devices has been obtained by using inorganic semiconductor materials. On the other hand, manufacture processes are very expensive in terms of both materials and techniques. For this reason organic-based photovoltaic (OPV cells are attracting the general attention because of the possible realization of more economical devices. Organic materials are abundant and easily handling. Unfortunately OPV cells efficiency is significantly lower than that of inorganic-based devices, representing a big point of weakness at the present. This is mainly due to the fact that organic semiconductors have a much higher band gap with respect to inorganic semiconductors. In addition, OPV cells are very susceptible to oxygen and water. In this paper we will describe some of the different approaches to the understanding and improving of organic photovoltaic devices.

  10. Using amorphous silicon solar cells to boost the viability of luminescent solar concentrators

    NARCIS (Netherlands)

    Farrell, D.J.; van Sark, W.G.J.H.M.; Velthuijsen, S.; Schropp, R.E.I.

    2010-01-01

    We have, for the first time, designed and fabricated hydrogenated amorphous silicon solar cells to be used in conjunction with Luminescent Solar Concentrators (LSCs). LSCs are planar plastic sheets doped with organic dyes that absorb solar illumination and down shift the energy to narrowband

  11. The Influence of Conduction Band Offset on CdTe Solar Cells

    Science.gov (United States)

    Chen, Yunfei; Tan, Xuehai; Peng, Shou; Xin, Cao; Delahoy, Alan E.; Chin, Ken K.; Zhang, Chuanjun

    2018-02-01

    Numerical modeling of conduction band offset (Δ E C) between an n-type CdSO window layer and a p-type CdTe absorption layer on the effect of the cadmium telluride (CdTe) solar cells was studied through simulation. The simulation results show that a slightly positive Δ E C yields high efficiency because the surface recombination rate at the CdSO/CdTe interface can be substantially reduced, leading to higher open-circuit voltage ( V OC) and fill factor. Further increase in Δ E C (≥ 0.4 eV) will impose an energy barrier against the photo-generated electrons under forward bias. We demonstrated the mechanistic picture of this effect using thermionic emission. However, if intra-band tunneling is considered in the simulation, a large Δ E C shows negligible influence on the performance of CdTe solar cells. Our simulation results suggest that an Δ E C of 0.3 eV is an optimal conduction band offset for high-efficiency CdTe solar cells.

  12. Trichosporon jirovecii-mediated synthesis of cadmium sulfide nanoparticles.

    Science.gov (United States)

    El-Baz, Ashraf Farag; Sorour, Noha Mohamed; Shetaia, Youssria Mohamed

    2016-05-01

    Cadmium sulphide is one of the most promising materials for solar cells and of great interest due to its useful applications in photonics and electronics, thus the development of bio-mediated synthesis of cadmium sulphide nanoparticles (CdS NPs) is one of the essential areas in nanoparticles. The present study demonstrates for the first time the eco-friendly biosynthesis of CdS NPs using the yeast Trichosporon jirovecii. The biosynthesis of CdS NPs were confirmed by UV-Vis spectrum and characterized by X-ray diffraction assay and electron microscopy. Scanning and transmission electron microscope analyses shows the formation of spherical CdS NPs with a size range of about 6-15 nm with a mean Cd:S molar ratio of 1.0:0.98. T. jirovecii produced hydrogen sulfide on cysteine containing medium confirmed by positive cysteine-desulfhydrase activity and the colony color turned yellow on 0.1 mM cadmium containing medium. T. jirovecii tolerance to cadmium was increased by the UV treatment and three 0.6 mM cadmium tolerant mutants were generated upon the UV radiation treatment. The overall results indicated that T. jirovecii could tolerate cadmium toxicity by its conversion into CdS NPs on cysteine containing medium using cysteine-desulfhydrase as a defense response mechanism. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Nanorods and nanotubes for solar cells.

    Science.gov (United States)

    Kislyuk, V V; Dimitriev, O P

    2008-01-01

    Nanorods and nanotubes as photoactive materials as well as electrodes in photovoltaic cells have been launched a few years ago, and the literature in this field started to appear only recently. The first steps have shown both advantages and disadvantages of their application, and the main expectation associated with their effective charge transport has not been realized completely. This article aims to review both the first and the recent tendencies in the development and application of nanorod and nanotube materials in photovoltaic cells. Two basic techniques of synthesis of crystalline nanorod structures are described, the top-down and bottom-up approaches, respectively. Design and photovoltaic performance of solar cells based on various semiconductor nanorod materials, such as TiO2, ZnO, CdS, CdSe, CdTe, CuO, Si are presented and compared with respective solar cells based on semiconductor nanoparticles. Specific of synthesis and application of carbon nanotubes in photovoltaic devices is also reviewed.

  14. Zinc supplementation protects against cadmium accumulation and cytotoxicity in Madin-Darby bovine kidney cells.

    Directory of Open Access Journals (Sweden)

    Ding Zhang

    Full Text Available Cadmium ions (Cd2+ have been reported to accumulate in bovine tissues, although Cd2+ cytotoxicity has not been investigated thoroughly in this species. Zinc ions (Zn2+ have been shown to antagonize the toxic effects of heavy metals such as Cd2+ in some systems. The present study investigated Cd2+ cytotoxicity in Madin-Darby bovine kidney (MDBK epithelial cells, and explored whether this was modified by Zn2+. Exposure to Cd2+ led to a dose- and time-dependent increase in apoptotic cell death, with increased intracellular levels of reactive oxygen species and mitochondrial damage. Zn2+ supplementation alleviated Cd2+-induced cytotoxicity and this protective effect was more obvious when cells were exposed to a lower concentration of Cd2+ (10 μM, as compared to 50 μM Cd2+. This indicated that high levels of Cd2+ accumulation might induce irreversible damage in bovine kidney cells. Metallothioneins (MTs are metal-binding proteins that play an essential role in heavy metal ion detoxification. We found that co-exposure to Zn2+ and Cd2+ synergistically enhanced RNA and protein expression of MT-1, MT-2, and the metal-regulatory transcription factor 1 in MDBK cells. Notably, addition of Zn2+ reduced the amounts of cytosolic Cd2+ detected following MDBK exposure to 10 μM Cd2+. These findings revealed a protective role of Zn2+ in counteracting Cd2+ uptake and toxicity in MDBK cells, indicating that this approach may provide a means to protect livestock from excessive Cd2+ accumulation.

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

    Science.gov (United States)

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

    2016-02-01

    Despite the increasing use of photovoltaics their potential environmental risks are poorly understood. Here, we compared ecotoxicological effects of two thin-film photovoltaics: established copper indium gallium selenide (CIGS) and organic photovoltaic (OPV) cells. Leachates were produced by exposing photovoltaics to UV light, physical damage, and exposure to environmentally relevant model waters, representing mesotrophic lake water, acidic rain, and seawater. CIGS cell leachates contained 583 μg L(-1) molybdenum at lake water, whereas at acidic rain and seawater conditions, iron, copper, zinc, molybdenum, cadmium, silver, and tin were present up to 7219 μg L(-1). From OPV, copper (14 μg L(-1)), zinc (87 μg L(-1)) and silver (78 μg L(-1)) leached. Zebrafish embryos were exposed until 120 h post-fertilization to these extracts. CIGS leachates produced under acidic rain, as well as CIGS and OPV leachates produced under seawater conditions resulted in a marked hatching delay and increase in heart edema. Depending on model water and solar cell, transcriptional alterations occurred in genes involved in oxidative stress (cat), hormonal activity (vtg1, ar), metallothionein (mt2), ER stress (bip, chop), and apoptosis (casp9). The effects were dependent on the concentrations of cationic metals in leachates. Addition of ethylenediaminetetraacetic acid protected zebrafish embryos from morphological and molecular effects. Our study suggests that metals leaching from damaged CIGS cells, may pose a potential environmental risk. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. CDTE alloys and their application for increasing solar cell performance

    Science.gov (United States)

    Swanson, Drew E.

    Cadmium Telluride (CdTe) thin film solar is the largest manufactured solar cell technology in the United States and is responsible for one of the lowest costs of utility scale solar electricity at a purchase agreement of $0.0387/kWh. However, this cost could be further reduced by increasing the cell efficiency. To bridge the gap between the high efficiency technology and low cost manufacturing, a research and development tool and process was built and tested. This fully automated single vacuum PV manufacturing tool utilizes multiple inline close space sublimation (CSS) sources with automated substrate control. This maintains the proven scalability of the CSS technology and CSS source design but with the added versatility of independent substrate motion. This combination of a scalable deposition technology with increased cell fabrication flexibility has allowed for high efficiency cells to be manufactured and studied. The record efficiency of CdTe solar cells is lower than fundamental limitations due to a significant deficit in voltage. It has been modeled that there are two potential methods of decreasing this voltage deficiency. The first method is the incorporation of a high band gap film at the back contact to induce a conduction-band barrier that can reduce recombination by reflecting electrons from the back surface. The addition of a Cd1-x MgxTe (CMT) layer at the back of a CdTe solar cell should induce this desired offset and reflect both photoelectrons and forward-current electrons away from the rear surface. Higher collection of photoelectrons will increase the cells current and the reduction of forward current will increase the cells voltage. To have the optimal effect, CdTe must have reasonable carrier lifetimes and be fully depleted. To achieve this experimentally, CdTe layers have been grown sufficiently thin to help produce a fully depleted cell. A variety of measurements including performance curves, transmission electron microscopy, x

  17. Industrialization of polymer solar cells - phase 1

    Energy Technology Data Exchange (ETDEWEB)

    Lauritzen, H.; Krebs, F.C. [Technical Univ. of Denmark. DTU Energy Conversion, DTU Risoe Campus, Roskilde (Denmark); Andersen, Rasmus B. [Mekoprint A/S, Stoevrimg (Denmark); Bork, J.; Bentzen, B.

    2012-03-15

    A three-phased project with the objective to industrialize DTU's basic polymer solar cell technology was started in the summer of 2009. The technology comprises a specific design of the polymer solar cell and a corresponding roll-to-roll manufacturing process. This basic technology is referred to as ProcessOne in the open literature. The present report relates to the project's phase 1.The key tasks in phase 1 are to stream-line DTU's tech-nology for the industrial utilization, to demonstrate production according to this stream-lined technology at Mekoprint A/S and finally to fertilize the market for polymer solar cells by demonstrating their use in appli-cations that harmonize with their present maturity level. The main focus in the stream-lining of DTU's technology has been to demonstrate a convincing rate of reduction for the production cost, and thereby make a competitive price plausible. This has been materialized as a learning curve showing that the polymer technology presently develops considerably faster than the silicon technology. The polymer solar cells will, under the assumption that both technologies follow a projection of the learning curve, gain a cost-leading position within a reasonable time. A production cost of 5 Euro/Wp has already been demonstrated in DTU's pilot plant, and a road map for the further decrease to 1 Euro/Wp is drawn. This target is expected to be reached in 2013 in the ongoing phase 2 of the project. Another activity essential for the industrialization has been the launch of specialized materials, equipment and services required for the processing of DTU's polymer solar cells. Relevant products and services are made available for sale on DTU's homepage, www.energyconversion.dtu.dk. A production line for polymer solar cells has been established at Mekoprint. For this a retrofit solution was chosen where the core of an existing screen-printing line was dismantled and fitted to a slot-die printing head manufactured in DTU's workshop

  18. Investigation of Indoor Stability Testing of Polymer Solar Cell

    Directory of Open Access Journals (Sweden)

    Pelin Kavak

    2016-01-01

    Full Text Available We have fabricated organic solar cell of a new low bandgap polymer poly[4,4-bis(2-ethylhexyl-4H-cyclopenta[2,1-b:3,4-b′]dithiophene-2,6-diyl-alt-4,7-bis(2-thienyl-2,1,3-benzothiadiazole-5′,5′′-diyl] (PCPDTTBTT. We have investigated for the first time the stability tests, ISOS-L-1 and ISOS-D-3, of PCPDTTBTT solar cells. Thermal annealing of PCPDTTBTT solar cells at 80°C brought about an improvement of photocurrent generation, stability, and efficiency of the solar cells. T80 value of PCPDTTBTT solar cell is about 150 hours which is close to P3HT (235 h. PCPDTTBTT is very promising polymer for both polymer solar cell efficiency and stability.

  19. Applications of Fluorogens with Rotor Structures in Solar Cells.

    Science.gov (United States)

    Ong, Kok-Haw; Liu, Bin

    2017-05-29

    Solar cells are devices that convert light energy into electricity. To drive greater adoption of solar cell technologies, higher cell efficiencies and reductions in manufacturing cost are necessary. Fluorogens containing rotor structures may be helpful in addressing some of these challenges due to their unique twisted structures and photophysics. In this review, we discuss the applications of rotor-containing molecules as dyes for luminescent down-shifting layers and luminescent solar concentrators, where their aggregation-induced emission properties and large Stokes shifts are highly desirable. We also discuss the applications of molecules containing rotors in third-generation solar cell technologies, namely dye-sensitized solar cells and organic photovoltaics, where the twisted 3-dimensional rotor structures are used primarily for aggregation control. Finally, we discuss perspectives on the future role of molecules containing rotor structures in solar cell technologies.

  20. Advantages of thin silicon solar cells for use in space

    Science.gov (United States)

    Denman, O. S.

    1978-01-01

    A system definition study on the Solar Power Satellite System showed that a thin, 50 micrometers, silicon solar cell has significant advantages. The advantages include a significantly lower performance degradation in a radiation environment and high power-to-mass ratios. The advantages of such cells for an employment in space is further investigated. Basic questions concerning the operation of solar cells are considered along with aspects of radiation induced performance degradation. The question arose in this connection how thin a silicon solar cell had to be to achieve resistance to radiation degradation and still have good initial performance. It was found that single-crystal silicon solar cells could be as thin as 50 micrometers and still develop high conversion efficiencies. It is concluded that the use of 50 micrometer silicon solar cells in space-based photovoltaic power systems would be advantageous.

  1. Recent progress in stability of perovskite solar cells

    Science.gov (United States)

    Qin, Xiaojun; Zhao, Zhiguo; Wang, Yidan; Wu, Junbo; Jiang, Qi; You, Jingbi

    2017-01-01

    Perovskite solar cells have attracted significant attention in just the past few years in solar cell research fields, where the power conversion efficiency was beyond 22.1%. Now, the most important challenge for perovskite solar cells in practical applications is the stability issue. In this mini-review, we will summarize the degradation mechanism of perovskite solar cells, including the perovskite material itself and also the interfaces. While we also provide our opinion on improving the stability of perovskite solar cells. Project supported by China Huaneng Group Project High Performance Perovskite Solar Cells (No. TW-15-HJK01), the National Key Research and Development Program of China (No. 2016YFB0700700), the National 1000 Young Talent Awards, and the National Natural Science Foundation of China (No. 61574133).

  2. Solar Cell Nanotechnology Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Das, Biswajit [Univ. of Nevada, Las Vegas, NV (United States)

    2014-05-07

    The objective of this project is to develop a low cost nonlithographic nanofabrication technology for the fabrication of thin film porous templates as well as uniform arrays of semiconductor nanostructures for the implementation of high efficiency solar cells. Solar cells based on semiconductor nanostructures are expected to have very high energy conversion efficiencies due to the increased absorption coefficients of semiconductor nanostructures. In addition, the thin film porous template can be used for optimum surface texturing of solar cells leading to additional enhancement in energy conversion efficiency. An important requirement for these applications is the ability to synthesize nanostructure arrays of different dimensions with good size control. This project employed nanoporous alumina templates created by the anodization of aluminum thin films deposited on glass substrates for the fabrication of the nanostructures and optimized the process parameters to obtain uniform pore diameters. An additional requirement is uniformity or regularity of the nanostructure arrays. While constant current anodization was observed to provide controlled pore diameters, constant voltage anodization was needed for regularity of the nanostructure arrays. Thus a two-step anodization process was investigated and developed in this project for improving the pore size distribution and pore periodicity of the nanoporous alumina templates. CdTe was selected to be the active material for the nanowires, and the process for the successful synthesis of CdTe nanowires was developed in this project. Two different synthesis approaches were investigated in this project, electrochemical and electrophoretic deposition. While electrochemical synthesis was successfully employed for the synthesis of nanowires inside the pores of the alumina templates, the technique was determined to be non-optimum due to the need of elevated temperature that is detrimental to the structural integrity of the

  3. Bioaccumulation of cadmium by growing Zygosaccharomyces rouxii and Saccharomyces cerevisiae.

    Science.gov (United States)

    Li, Chunsheng; Jiang, Wei; Ma, Ning; Zhu, Yinglian; Dong, Xiaoyan; Wang, Dongfeng; Meng, Xianghong; Xu, Ying

    2014-03-01

    Bioaccumulation via growing cells is a potential technique for heavy metal removal from food materials. The cadmium bioaccumulation characteristics by growing Zygosaccharomyces rouxii and Saccharomyces cerevisiae were investigated. Z. rouxii displayed powerful cadmium removal ability at low cadmium concentrations, which mainly depended on the intracellular cadmium bioaccumulation. The percentage of intracellular cadmium bioaccumulation of both yeasts obviously decreased with the increase of initial biomass and cadmium concentrations. Low pH and elevated concentrations of zinc and copper significantly decreased the intracellular cadmium bioaccumulation of both yeasts but improved the cadmium tolerance and the cell-surface cadmium bioaccumulation of Z. rouxii. Cadmium removal of Z. rouxii was improved by zinc and copper conditionally. Z. rouxii that possessed more powerful cadmium tolerance and removal ability at low pH and high concentration of competing ions can be developed into a potential cadmium removal agent using in complex food environment in future. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Materials availability for thin film solar cells

    Science.gov (United States)

    Makita, Yunosuke

    1997-04-01

    Materials availability is one of the most important factors when we consider the mass-production of next generation photovoltaic devices. "In (indium)" is a vital element to produce high efficient thin film solar cells such as InP and CuIn(Ga)Se2 but its lifetime as a natural resource is suggested to be of order of 10˜15 years. The lifetime of a specific natural resource as an element to produce useful device substances is directly related with its abundance in the earth's crust, consumption rate and recycling rate (if recycling is economically meaningful). The chemical elements having long lifetime as a natural resource are those existing in the atmosphere such as N (nitrogen) and O (oxygen); the rich elements in the earth's crust such as Si, Ca, Sr and Ba; the mass-used metals such as Fe (iron), Al (aluminum) and Cu (copper) that reached the stage of large-scale recycling. We here propose a new paradigm of semiconductor material-science for the future generation thin film solar cells in which only abundant chemical elements are used. It is important to remark that these abundant chemical elements are normally not toxic and are fairly friendly to the environment. β-FeSi2 is composed of two most abundant and nontoxic chemical elements. This material is one of the most promising device materials for future generation energy devices (solar cells and thermoelectric device that is most efficient at temperature range of 700-900 °C). One should remind of the versatility of β-FeSi2 that this material can be used not only as energy devices but also as photodetector, light emitting diode and/or laser diode at the wavelength of 1.5 μm that can be monolithically integrated on Si substrates due to the relatively small lattice mismatch.

  5. Device physics of polymer: fullerene bulk heterojunction solar cells

    OpenAIRE

    Blom, Paul W. M.; Mihailetchi, Valentin D.; Koster, L. Jan Anton; Markov, Denis E.

    2007-01-01

    Plastic solar cells bear the potential for large-scale power generation based on materials that provide the possibility of flexible, lightweight, inexpensive, efficient solar cells. Since the discovery of the photoinduced electron transfer from a conjugated polymer to fullerene molecules, followed by the introduction of the bulk heterojunction (BHJ) concept, this material combination has been extensively studied in organic solar cells, leading to several breakthroughs in efficiency, with a po...

  6. Nanoscale dimples for improved absorption in organic solar cells

    DEFF Research Database (Denmark)

    Goszczak, Arkadiusz Jaroslaw; Rubahn, Horst-Günter; Madsen, Morten

    Organic solar cells (OSC’s) have attracted much attention in the past years due to their potential low-cost, light-weight and mechanical flexibility. A method for improving the power conversion efficiencies of the devices is by incorporating structured electrodes in the solar cell architecture...... ordered and discorded dimple arrangement and their contribution to light management is presented. Such dimples can later be employed to fabricate nanostructured electrodes in P3HT/PCBM organic solar cells....

  7. Inexpensive transparent nanoelectrode for crystalline silicon solar cells

    OpenAIRE

    Peng, Qiang; Pei, Ke; Han, Bing; Li, Ruopeng; Zhou, Guofu; Liu, Jun-Ming; Kempa, Krzysztof; Gao, Jinwei

    2016-01-01

    We report an easily manufacturable and inexpensive transparent conductive electrode for crystalline silicon (c-Si) solar cells. It is based on a silver nanoparticle network self-forming in the valleys between the pyramids of a textured solar cell surface, transformed into a nanowire network by sintering, and subsequently ?buried? under the silicon surface by a metal-assisted chemical etching. We have successfully incorporated these steps into the conventional c-Si solar cell manufacturing pro...

  8. Stability and Degradation of Polymer Solar cells

    DEFF Research Database (Denmark)

    Norrman, Kion

    The current state-of-the-art allows for roll-to-roll manufacture of polymer solar cells in high volume with stability and efficiency sufficient to grant success in low-energy applications. However, further improvement is needed for the successful application of the devices in real life applications....... This is obtained by detailed knowledge of the degradation mechanisms. Methods to compare and standardize device stability are urgently needed. Methodologies to study failure mechanism that are based on physical processes (e.g. morphological changes) are well-established. However, methodologies to study chemical...

  9. Dye solar cell research: EU delegation presentation

    CSIR Research Space (South Africa)

    Cummings, F

    2009-11-09

    Full Text Available Franscious Cummings Energy and Processes Materials Science and Manufacturing Council for Scientific and Industrial Research P.O. Box 395 Pretoria 0001, South Africa 13 November 2009 © CSIR 2007 www.csir.co.za CONTENT head2right...Background head2rightCSIR Dye Solar Cell Research head2rightCollaborations and Links head2rightAcknowledgements © CSIR 2007 www.csir.co.za BACKGROUND head2rightSA is dry: Annual rainfall average of 450 mm compared with a world average...

  10. Method of fabricating bifacial tandem solar cells

    Science.gov (United States)

    Wojtczuk, Steven J; Chiu, Philip T; Zhang, Xuebing; Gagnon, Edward; Timmons, Michael

    2014-10-07

    A method of fabricating on a semiconductor substrate bifacial tandem solar cells with semiconductor subcells having a lower bandgap than the substrate bandgap on one side of the substrate and with subcells having a higher bandgap than the substrate on the other including, first, growing a lower bandgap subcell on one substrate side that uses only the same periodic table group V material in the dislocation-reducing grading layers and bottom subcells as is present in the substrate and after the initial growth is complete and then flipping the substrate and growing the higher bandgap subcells on the opposite substrate side which can be of different group V material.

  11. Intermediate Bandgap Solar Cells From Nanostructured Silicon

    Energy Technology Data Exchange (ETDEWEB)

    Black, Marcie [Bandgap Engineering, Lincoln, MA (United States)

    2014-10-30

    This project aimed to demonstrate increased electronic coupling in silicon nanostructures relative to bulk silicon for the purpose of making high efficiency intermediate bandgap solar cells using silicon. To this end, we formed nanowires with controlled crystallographic orientation, small diameter, <111> sidewall faceting, and passivated surfaces to modify the electronic band structure in silicon by breaking down the symmetry of the crystal lattice. We grew and tested these silicon nanowires with <110>-growth axes, which is an orientation that should produce the coupling enhancement.

  12. Baselines for Lifetime of Organic Solar Cells

    DEFF Research Database (Denmark)

    Gevorgyan, Suren; Espinosa Martinez, Nieves; Ciammaruchi, Laura

    2016-01-01

    The process of accurately gauging lifetime improvements in organic photovoltaics (OPVs) or other similar emerging technologies, such as perovskites solar cells is still a major challenge. The presented work is part of a larger effort of developing a worldwide database of lifetimes that can help...... the baselines of lifetime for OPVs tested under different conditions. The work also provides the recent progress in stability of unencapsulated OPVs with different architectures, as well as presents the updated diagram of the reported record lifetimes of OPVs. The presented work is another step forward towards...

  13. Flexible ITO-Free Polymer Solar Cells

    DEFF Research Database (Denmark)

    Angmo, Dechan; Krebs, Frederik C

    2013-01-01

    Indium tin oxide (ITO) is the material-of-choice for transparent conductors in any optoelectronic application. However, scarce resources of indium and high market demand of ITO have created large price fluctuations and future supply concerns. In polymer solar cells (PSCs), ITO is the single......-cost alternatives to ITO suitable for use in PSCs. These alternatives belong to four material groups: polymers; metal and polymer composites; metal nanowires and ultra-thin metal films; and carbon nanotubes and graphene. We further present the progress of employing these alternatives in PSCs and identify future...

  14. Solar-Hydrogen Fuel-Cell Vehicles

    OpenAIRE

    DeLuchi, Mark A.; Ogden, Joan M.

    1993-01-01

    Hydrogen is an especially attractive transportation fuel. It is the least polluting fuel available, and can be produced anywhere there is water and a clean source of electricity. A fuel cycle in which hydrogen is produced by solar-electrolysis of water, or by gasification of renewably grown biomass, and then used in a fuel-cell powered electric-motor vehicle (FCEV), would produce little or no local, regional or global pollution. Hydrogen FCEVs would combine the best features of battery-powere...

  15. Photon recycling in the graded bandgap solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Rafat, N.H. [Cairo Univ., Dept. of Mathematics and Engineering Physics, Giza (Egypt); Haleem, A.M. Abdel [Cairo Univ., Dept. of Mathematics and Engineering Physics, EIFayoum (Egypt); Habib, S.E.D. [Cairo Univ., Electronics and Communication Dept., Giza (Egypt)

    2006-07-01

    We derived a general integral expression for the carrier radiative recombination rate in solar cells. The photon Boltzmann equation is solved taking into account the photon recycling effect inside the cell and assuming arbitrary spatial variation of the absorption coefficient. This expression can thus be used for graded bandgap solar cells. (Author)

  16. High efficiency solar cells for laser power beaming applications

    Science.gov (United States)

    Jain, Raj K.; Landis, G. A.

    1995-01-01

    Understanding solar cell response to pulsed laser outputs is important for the evaluation of power beaming applications. The time response of high efficiency GaAs and silicon solar cells to a 25 nS monochromatic pulse input is described. The PC-1D computer code is used to analyze the cell current during and after the pulse for various conditions.

  17. Performance improvement of silicon solar cells by nanoporous silicon coating

    Directory of Open Access Journals (Sweden)

    Dzhafarov T. D.

    2012-04-01

    Full Text Available In the present paper the method is shown to improve the photovoltaic parameters of screen-printed silicon solar cells by nanoporous silicon film formation on the frontal surface of the cell using the electrochemical etching. The possible mechanisms responsible for observed improvement of silicon solar cell performance are discussed.

  18. Plasmonic ZnO/p-silicon heterojunction solar cell

    Science.gov (United States)

    Shokeen, Poonam; Jain, Amit; Kapoor, Avinashi

    2017-05-01

    A ZnO/p-Si heterojunction solar cell has been fabricated by sol-gel technique. Silver nanostructures have been deposited on the top surface of the cell by pulsed laser deposition (PLD) system. Silver nanoparticles show strong surface plasmon resonance at 500 nm and improve the overall absorbance of the cell. Deposition of silver nanoparticles on the top surface of the solar cell quenches the photoluminescence and indicates an effective scattering of incident light into the absorber layer. A solar cell containing silver nanoparticles shows fivefold improvement in short circuit current density in comparison to a pristine cell. Finite-difference time-domain (FDTD) simulations illustrate the effect of silver nanoparticles on the performance of the solar cell. The total quantum efficiency (TQE) of the device shows a Gaussian curve with the aspect ratio (diameter: interspacing) of nanoparticles. Optimized distribution of silver nanoparticles can improve the light trapping capabilities of various thin-film solar cells.

  19. Flexible PCPDTBT:PCBM solar cells with integrated grating structures

    DEFF Research Database (Denmark)

    Oliveira Hansen, Roana Melina de; Liu, Yinghui; Madsen, Morten

    2013-01-01

    spectra of the active layer. This optimized solar cell structure leads to an enhanced absorption in the active layer and thus improved short-circuit currents and power conversion efficiencies in the fabricated devices. Fabrication of the solar cells on thin polyimide substrates which are compatible......We report on development of flexible PCPDTBT:PCBM solar cells with integrated diffraction gratings on the bottom electrodes. The presented results address PCPDTBT:PCBM solar cells in an inverted geometry, which contains implemented grating structures whose pitch is tuned to match the absorption...

  20. Stability and Degradation of Organic and Polymer Solar Cells

    DEFF Research Database (Denmark)

    Organic photovoltaics (OPV) are a new generation of solar cells with the potential to offer very short energy pay back times, mechanical flexibility and significantly lower production costs compared to traditional crystalline photovoltaic systems. A weakness of OPV is their comparative instability...... during operation and this is a critical area of research towards the successful development and commercialization of these 3rd generation solar cells. Covering both small molecule and polymer solar cells, Stability and Degradation of Organic and Polymer Solar Cells summarizes the state of the art...

  1. Organic solar cells theory, experiment, and device simulation

    CERN Document Server

    Tress, Wolfgang

    2014-01-01

    This book covers in a textbook-like fashion the basics or organic solar cells, addressing the limits of photovoltaic energy conversion and giving a well-illustrated introduction to molecular electronics with focus on the working principle and characterization of organic solar cells. Further chapters based on the author's dissertation focus on the electrical processes in organic solar cells by presenting a detailed drift-diffusion approach to describe exciton separation and charge-carrier transport and extraction. The results, although elaborated on small-molecule solar cells and with focus on

  2. Nanostructured InGaP Solar Cells Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The operating conditions of conventional multijunction solar cells are severely limited by the current matching requirements of serially connected devices. The goal...

  3. Stability and Degradation of Organic and Polymer Solar Cells

    DEFF Research Database (Denmark)

    during operation and this is a critical area of research towards the successful development and commercialization of these 3rd generation solar cells. Covering both small molecule and polymer solar cells, Stability and Degradation of Organic and Polymer Solar Cells summarizes the state of the art......Organic photovoltaics (OPV) are a new generation of solar cells with the potential to offer very short energy pay back times, mechanical flexibility and significantly lower production costs compared to traditional crystalline photovoltaic systems. A weakness of OPV is their comparative instability...... measures for extending the duration of operation....

  4. Molecular doping of low-bandgap-polymer:fullerene solar cells: Effects on transport and solar cells

    NARCIS (Netherlands)

    Tunc, Ali Veysel; Sio, Antonietta De; Riedel, Daniel; Deschler, Felix; Da Como, Enrico; Parisi, Juergen; von Hauff, Elizabeth

    We show how molecular doping can be implemented to improve the performance of solution processed bulk heterojunction solar cells based on a low-bandgap polymer mixed with a fullerene derivative. The molecular dopant 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ) is introduced into

  5. Characteristics of the New Solar Cell Power Supply System

    OpenAIRE

    松尾, 博文; 黒川, 不二雄; 川原, 学

    1982-01-01

    Recently, the solar cell has been used as power sources for the radio relay stations, the light houses, the agricultural systems, the microwave communication systems, and so forth. In such solar call power supply systems, it often requires that the maximum power point of the solar array is tracked, in spite of the variations in the load and the light intensity, to make the most efficient use of the solar array and the storage battery. The purpose of this paper is to propose a new solar cell ...

  6. Recyclable organic solar cells on cellulose nanocrystal substrates.

    Science.gov (United States)

    Zhou, Yinhua; Fuentes-Hernandez, Canek; Khan, Talha M; Liu, Jen-Chieh; Hsu, James; Shim, Jae Won; Dindar, Amir; Youngblood, Jeffrey P; Moon, Robert J; Kippelen, Bernard

    2013-01-01

    Solar energy is potentially the largest source of renewable energy at our disposal, but significant advances are required to make photovoltaic technologies economically viable and, from a life-cycle perspective, environmentally friendly, and consequently scalable. Cellulose nanomaterials are emerging high-value nanoparticles extracted from plants that are abundant, renewable, and sustainable. Here, we report on the first demonstration of efficient polymer solar cells fabricated on optically transparent cellulose nanocrystal (CNC) substrates. The solar cells fabricated on the CNC substrates display good rectification in the dark and reach a power conversion efficiency of 2.7%. In addition, we demonstrate that these solar cells can be easily separated and recycled into their major components using low-energy processes at room temperature, opening the door for a truly recyclable solar cell technology. Efficient and easily recyclable organic solar cells on CNC substrates are expected to be an attractive technology for sustainable, scalable, and environmentally-friendly energy production.

  7. A Solar Cell That Is Triggered by Sun and Rain.

    Science.gov (United States)

    Tang, Qunwei; Wang, Xiaopeng; Yang, Peizhi; He, Benlin

    2016-04-18

    All-weather solar cells are promising in solving the energy crisis. A flexible solar cell is presented that is triggered by combining an electron-enriched graphene electrode with a dye-sensitized solar cell. The new solar cell can be excited by incident light on sunny days and raindrops on rainy days, yielding an optimal solar-to-electric conversion efficiency of 6.53 % under AM 1.5 irradiation and current over microamps as well as a voltage of hundreds of microvolts by simulated raindrops. The formation of π-electron|cation electrical double-layer pseudocapacitors at graphene/raindrop interface is contributable to current and voltage outputs at switchable charging-discharging process. The new concept can guide the design of advanced all-weather solar cells. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Effects of radiation on solar cells as photovoltaic generators

    Directory of Open Access Journals (Sweden)

    Radosavljević Radovan Lj.

    2012-01-01

    Full Text Available The growing need for obtaining electrical energy through renewable energy sources such as solar energy have lead to significant technological developments in the production of the basic element of PV conversion, the solar cell. Basically, a solar cell is a p-n junction whose characteristics have a great influence on its output parameters, primarily efficiency. Defects and impurities in the basic material, especially if located within the energy gap, may be activated during its lifetime, becoming traps for optically produced electron-hole pairs and, thus, decreasing the output power of the cell. All of the said effects could be induced in many ways over a lifetime of a solar cell and are consistent with the effects that radiation produces in semiconductor devices. The aim of this paper is to investigate changes in the main characteristics of solar cells, such as efficiency, output current and power, due to the exposure of solar systems to different (hostile radiation environments.

  9. Recyclable organic solar cells on cellulose nanocrystal substrates

    Science.gov (United States)

    Zhou, Yinhua; Fuentes-Hernandez, Canek; Khan, Talha M.; Liu, Jen-Chieh; Hsu, James; Shim, Jae Won; Dindar, Amir; Youngblood, Jeffrey P.; Moon, Robert J.; Kippelen, Bernard

    2013-01-01

    Solar energy is potentially the largest source of renewable energy at our disposal, but significant advances are required to make photovoltaic technologies economically viable and, from a life-cycle perspective, environmentally friendly, and consequently scalable. Cellulose nanomaterials are emerging high-value nanoparticles extracted from plants that are abundant, renewable, and sustainable. Here, we report on the first demonstration of efficient polymer solar cells fabricated on optically transparent cellulose nanocrystal (CNC) substrates. The solar cells fabricated on the CNC substrates display good rectification in the dark and reach a power conversion efficiency of 2.7%. In addition, we demonstrate that these solar cells can be easily separated and recycled into their major components using low-energy processes at room temperature, opening the door for a truly recyclable solar cell technology. Efficient and easily recyclable organic solar cells on CNC substrates are expected to be an attractive technology for sustainable, scalable, and environmentally-friendly energy production. PMID:23524333

  10. Photosensitizers from Spirulina for Solar Cell

    Directory of Open Access Journals (Sweden)

    Liqiu Wang

    2014-01-01

    Full Text Available Spirulina is a kind of blue-green algae with good photosynthetic efficiency and might be used for photovoltaic power generation. So this paper used living spirulina as novel photosensitizer to construct spirulina biosolar cell. The results showed that spirulina had the photoelectric conversion effect, and could let the spirulina biosolar cell have 70 μA photocurrent. Meanwhile, adding glucose sucrose or chitosan in the spirulina anode chamber, they could make the maxima current density of the cell greatly increased by 80 μA, 100 μA, and 84 μA, respectively, and the sucrose could improve the maximum power density of the cell to 63 mW/m−2. Phycobiliprotein played an important role in the photosynthesis of spirulina. So in this paper phycobiliprotein was extracted from spirulina to composite with squaraine dye to sensitize nanocrystalline TiO2 photoanode for building dye sensitized solar cell, and the photoelectric properties of the cell also were investigated.

  11. A three solar cell system based on a self-supporting, transparent AlGaAs top solar cell

    Science.gov (United States)

    Negley, Gerald H.; Rhoads, Sandra L.; Terranova, Nancy E.; Mcneely, James B.; Barnett, Allen M.

    1989-01-01

    Development of a three solar cell stack can lead to practical efficiencies greater than 30 percent (1x,AM0). A theoretical efficiency limitation of 43.7 percent at AM0 and one sun is predicted by this model. Including expected losses, a practical system efficiency of 36.8 percent is anticipated. These calculations are based on a 1.93eV/1.43eV/0.89eV energy band gap combination. AlGaAs/GaAs/GaInAsP materials can be used with a six-terminal wiring configuration. The key issues for multijunction solar cells are the top and middle solar cell performance and the sub-bandgap transparency. AstroPower has developed a technique to fabricate AlGaAs solar cells on rugged, self-supporting, transparent AlGaAs substrates. Top solar cell efficiencies greater than 11 percent AM0 have been achieved. State-of-the-art GaAs or InP devices will be used for the middle solar cell. GaInAsP will be used to fabricate the bottom solar cell. This material is lattice-matched to InP and offers a wide range of bandgaps for optimization of the three solar cell stack. Liquid phase epitaxy is being used to grow the quaternary material. Initial solar cells have shown open-circuit voltages of 462 mV for a bandgap of 0.92eV. Design rules for the multijunction three solar cell stack are discussed. The progress in the development of the self-supporting AlGaAs top solar cell and the GaInAsP bottom solar cell is presented.

  12. Biosorption of lead, copper and cadmium using the extracellular polysaccharides (EPS) of Bacillus sp., from solar salterns.

    Science.gov (United States)

    Shameer, Syed

    2016-12-01

    Extracellular Polysaccharides (EPS) from both prokaryotes and eukaryotes have a great deal of research interest as they protect the producer from different stresses including antibiotics, ionic stress, desiccation and assist in bio-film formation, pathogenesis, adhesion, etc. In this study haloalkaliphilic Bacillus sp., known to cope with osmophilic stress, was selected and screened for EPS production. The EPS were isolated, partially purified and chemical characteristics were documented using liquid FT-IR followed by assessment of heavy metal biosorption (lead, copper and cadmium) using Atomic Absorption Spectroscopy (AAS). The EPS extracted from three isolates B. licheniformis NSPA5, B. cereus NSPA8 and B. subtilis NSPA13 showed maximum biosorption of Lead followed by Copper and Cadmium. Of the tested isolates, the EPS from isolate B. cereus NSPA8 showed maximum (90 %) biosorption of the lead.

  13. Gallium arsenide quantum well-based far infrared array radiometric imager

    Science.gov (United States)

    Forrest, Kathrine A.; Jhabvala, Murzy D.

    1991-01-01

    We have built an array-based camera (FIRARI) for thermal imaging (lambda = 8 to 12 microns). FIRARI uses a square format 128 by 128 element array of aluminum gallium arsenide quantum well detectors that are indium bump bonded to a high capacity silicon multiplexer. The quantum well detectors offer good responsivity along with high response and noise uniformity, resulting in excellent thermal images without compensation for variation in pixel response. A noise equivalent temperature difference of 0.02 K at a scene temperature of 290 K was achieved with the array operating at 60 K. FIRARI demonstrated that AlGaAS quantum well detector technology can provide large format arrays with performance superior to mercury cadmium telluride at far less cost.

  14. Sensitizers for Aqueous-Based Solar Cells.

    Science.gov (United States)

    Li, Chun-Ting; Lin, Ryan Yeh-Yung; Lin, Jiann T

    2017-03-02

    Aqueous dye-sensitized solar cells (DSSCs) are attractive due to their sustainability, the use of water as a safe solvent for the redox mediators, and their possible applications in photoelectrochemical water splitting. However, the higher tendency of dye leaching by water and the lower wettability of dye molecules are two major obstacles that need to be tackled for future applications of aqueous DSSCs. Sensitizers designed for aqueous DSSCs are discussed based on their functions, such as modification of the molecular skeleton and the anchoring group for better stability against dye leaching by water, and the incorporation of hydrophilic entities into the dye molecule or the addition of a surfactant to the system to increase the wettability of the dye for more facile dye regeneration. Surface treatment of the photoanode to deter dye leaching or improve the wettability of the dye molecule is also discussed. Redox mediators designed for aqueous DSSCs are also discussed. The review also includes quantum-dot-sensitized solar cells, with a focus on improvements in QD loading and suppression of interfacial charge recombination at the photoanode. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Hybrid Perovskite/Perovskite Heterojunction Solar Cells.

    Science.gov (United States)

    Hu, Yinghong; Schlipf, Johannes; Wussler, Michael; Petrus, Michiel L; Jaegermann, Wolfram; Bein, Thomas; Müller-Buschbaum, Peter; Docampo, Pablo

    2016-06-28

    Recently developed organic-inorganic hybrid perovskite solar cells combine low-cost fabrication and high power conversion efficiency. Advances in perovskite film optimization have led to an outstanding power conversion efficiency of more than 20%. Looking forward, shifting the focus toward new device architectures holds great potential to induce the next leap in device performance. Here, we demonstrate a perovskite/perovskite heterojunction solar cell. We developed a facile solution-based cation infiltration process to deposit layered perovskite (LPK) structures onto methylammonium lead iodide (MAPI) films. Grazing-incidence wide-angle X-ray scattering experiments were performed to gain insights into the crystallite orientation and the formation process of the perovskite bilayer. Our results show that the self-assembly of the LPK layer on top of an intact MAPI layer is accompanied by a reorganization of the perovskite interface. This leads to an enhancement of the open-circuit voltage and power conversion efficiency due to reduced recombination losses, as well as improved moisture stability in the resulting photovoltaic devices.

  16. Bifacial Perovskite Solar Cells Featuring Semitransparent Electrodes.

    Science.gov (United States)

    Hanmandlu, Chintam; Chen, Chien-Yu; Boopathi, Karunakara Moorthy; Lin, Hao-Wu; Lai, Chao-Sung; Chu, Chih-Wei

    2017-09-27

    Inorganic-organic hybrid perovskite solar cells (PSCs) are promising devices for providing future clean energy because of their low cost, ease of fabrication, and high efficiencies, similar to those of silicon solar cells. These materials have been investigated for their potential use in bifacial PSCs, which can absorb light from both sides of the electrodes. Here, we fabricated bifacial PSCs featuring transparent BCP/Ag/MoO3 rear electrodes, which we formed through low-temperature processing using thermal evaporation methods. We employed a comprehensive optical distribution program to calculate the distributions of the optical field intensities with constant thicknesses of the absorbing layer in the top electrode configuration. The best PSC having a transparent BCP/Ag/MoO3 electrode achieved PCEs of 13.49% and 9.61% when illuminated from the sides of the indium tin oxide and BCP/Ag/MoO3 electrodes, respectively. We observed significant power enhancement when operating this PSC using mirror reflectors and bifacial light illumination from both sides of the electrodes.

  17. Intake of Boron, Cadmium, and Molybdenum enhances rat thyroid cell transformation.

    Science.gov (United States)

    Luca, Emilia; Fici, Laura; Ronchi, Anna; Marandino, Ferdinando; Rossi, Esther Diana; Caristo, Maria Emiliana; Malandrino, Pasqualino; Russo, Marco; Pontecorvi, Alfredo; Vigneri, Riccardo; Moretti, Fabiola

    2017-06-02

    Epidemiologic data in volcanic areas suggest that environmental factors might be involved in the increase of thyroid cancer (TC) incidence. Recent reports indicate that several heavy metals and metalloids are increased in volcanic areas. This study aims to evaluate the combined effect of three of these elements Boron (B), Cadmium (Cd), and Molybdenum (Mo) - all increased in the volcanic area of Mt. Etna, in Italy - on thyroid tumorigenesis in the rat. Female Wistar rats prone to develop thyroid tumors by low-iodine diet and methimazole treatment received ad libitum drinking water supplemented with B, Cd, and Mo at concentrations in the range found in the urine samples of residents of the volcanic area. At 5 and 10 months animals were euthanized, and their thyroid analysed. Statistical analysis was performed with a 2-way unpaired t-test. No toxic effect of the three elements on the growth of the animals was observed. A significant increase of histological features of transformation was observed in thyroid follicular cells of rats treated with B, Cd, and Mo compared with those of control group. These abnormalities were associated with decreased iodine content in the thyroid. This study provides the evidence that slightly increased environmental concentrations of B, Cd, and Mo can accelerate the appearance of transformation marks in the thyroid gland of hypothyroid rats.

  18. Biosorption of Cadmium and Manganese Using Free Cells of Klebsiella sp. Isolated from Waste Water

    Science.gov (United States)

    Hou, Yunnan; Cheng, Keke; Li, Zehua; Ma, Xiaohui; Wei, Yahong; Zhang, Lei; Wang, Yao

    2015-01-01

    In the present study, we evaluated a bacterium that was isolated from waste water for its ability to take up cadmium and manganese. The strain, identified both biochemically and by its 16S rRNA gene sequence as Klebsiella, was named Yangling I2 and was found to be highly resistant to heavy metals. Surface characterization of the bacterium via SEM revealed gross morphological changes, with cells appearing as biconcave discs after metal exposure rather than their typical rod shape. The effects of pH, temperature, heavy metal concentration, agitation and biomass concentration on the uptake of Cd(II) and Mn(II) was measured using atomic absorption spectrophotometry. The results showed that the biosorption was most affected by pH and incubation temperature, being maximized at pH 5.0 and 30°C, with absorption capacities of 170.4 and 114.1 mg/g for Cd(II) and Mn(II), respectively. Two models were investigated to compare the cells’ capacity for the biosorption of Cd and Mn, and the Langmuir model based on fuzzy linear regression was found to be close to the observed absorption curves and yield binding constants of 0.98 and 0.86 for Cd and Mn, respectively. This strain of Klebsiella has approximately ten times the absorption capacity reported for other strains and is promising for the removal of heavy metals from waste water. PMID:26505890

  19. Synthesis of mercaptosuccinic acid/MercaptoPolyhedral oligomeric silsesquioxane coated cadmium telluride quantum dots in cell labeling applications.

    Science.gov (United States)

    Ghaderi, Shirin; Ramesh, Bala; Seifalian, Alexander M

    2012-06-01

    An aqueous synthesis method to obtain highly luminescent cadmium telluride nanocrystals is described. We have shown water-soluble semi-conductor quantum dots with high photoluminescence quantum yield have great potential for biological applications. The spectral properties of these nanocrystals can be easily tuned according to their particle size to yield multicolours simultaneously by a single excitation light source. A stable precursor material sodium tellurite is utilised instead of the traditional oxygen sensitive NaHTe or H2Te as Te source. We have introduced mercaptosuccinic acid and propylisobutyl polyhedral oligomeric silsesquioxane nanoparticles as novel capping agents to stabilize the nanocrystals, synthesized in borate-citrate buffering system. Inclusion of propylisobutyl polyhedral oligomeric silsesquioxane nanoparticles in the capping procedure showed enhanced stability and biocompatibility. The presence of mercaptosuccinic acid/propylisobutyl polyhedral oligomeric silsesquioxane coatings was confirmed by Fourier Transform Infrared spectroscopy and average sizes of 2-5 nm by transmission electron microscopy measurements. The functionalized and targeted quantum dots detected cancer cell death on exposure to some anticancer drugs. Studies have indicated that apoptotic cells can activate signaling pathways in dendritic cells via ligation of surface receptors. Cells treated with specific class of pro-apototic drug such as anthracyclines mount an anti-tumour immune response when introduced into mice. Apoptotic cells may be immunogenic or non-immunogenic depending on the presence of calreticulin on the plasma membrane of dying tumour cells. Here the confocal microscopy showed localization of conjugated mercaptosuccinic acid/propylisobutyl polyhedral oligomeric silsesquioxane cadmium telluride quantum dots on MCF-7 cells when exposed to cadmium ions at 50 microM, compared to coated quantum dots. We have used cadmium ions as a model drug as certain anticancer

  20. Characterization of chemical bath deposited buffer layers for thin film solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Dwyer, D.; Efstathiadis, H.; Haldar, P. [College of Nanoscale Science and Engineering, University at Albany - State University of New York, 257 Fuller Rd., Albany, NY 12203 (United States); Sun, R. [Angstrom Sun Technologies Inc., 33 Nagog Park, Acton, MA 01720 (United States)

    2010-10-15

    Cadmium sulfide (CdS), indium sulfide (In{sub 2}S{sub 3}) and zinc sulfide (ZnS) thin films have been deposited by chemical bath deposition (CBD) for buffer layer applications in Cu-chalcopyrite-based thin film solar cells. Films were characterized by scanning electron microscopy (SEM), UV-Vis transmission, X-ray photoelectron spectroscopy (XPS), grazing-incidence X-ray diffraction (GIXRD), and spectroscopic ellipsometry. Results indicate CdS can be deposited with low oxygen content and high light transmission over 245-1700 nm. CBD-ZnS and CBD-InS both exhibit 5-10% less light transmission than CdS in the same thickness range. In terms of light transmission and degree of impurities CdS appears to be a better buffer material than CBD-ZnS or CBD-InS. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  1. Effect of Mn Doping on Properties of CdS Quantum Dot-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Tianxing Li

    2014-01-01

    Full Text Available Quantum dot-sensitized solar cells (QDSSCs have received extensive attention in recent years due to their higher theoretical conversion efficiency and lower production costs. However, the photoelectric conversion efficiency of QDSSCs is still lower than the DSSCs because of the severe recombination of electrons of quantum dots conduction band. In order to improve the photoelectric conversion efficiency of QDSSCs, impurity element Mn2+ is doped into the precursor solution of cadmium sulfide (CdS. By optimizing the experimental parameters, the photoelectric conversion efficiency of QDSSCs can be greatly improved. For the deposition of a fixed number of six times, the photoelectric conversion efficiency shows the maximum value (1.51% at the doped ratio of 1 : 10.

  2. Metal Matrix Composite Solar Cell Metallization

    Directory of Open Access Journals (Sweden)

    Wilt David M.

    2017-01-01

    Full Text Available Advanced solar cells are moving to ever thinner formats in order to save mass and in some cases improve performance. As cells are thinned, the possibility that they may fracture or cleave due to mechanical stresses is increased. Fractures of the cell can degrade the overall device performance if the fracture propagates through the contact metallization, which frequently occurs. To address this problem, a novel semiconductor metallization system based on multi-walled carbon nanotube (CNT reinforcement, termed metal matrix composite (MMC metallization is under investigation. Electro-mechanical characterization of MMC films demonstrate their ability to provide electrical conductivity over >40 micron wide cracks in the underlying semiconductor, with the carbon nanotubes bridging the gap. In addition, these materials show a “self-healing” behaviour, electrically reconnecting at ~30 microns when strained past failure. Triple junction (TJ space cells with MMC metallization demonstrated no loss in Jsc after intentional fracture, whereas TJ cells with conventional metallization suffer up to 50% Jsc loss.

  3. Experimental Investigation on Thermoelectric Chiller Driven by Solar Cell

    Directory of Open Access Journals (Sweden)

    Yen-Lin Chen

    2014-01-01

    Full Text Available This paper presents experimental explorations on cooling performance of thermoelectric chillers being driven by solar cells, as well as comparison results to the performance being driven by fixed direct current. Solar energy is clear and limitless and can be collected by solar cells. We use solar cells to drive thermoelectric chillers, where the cold side is connected to the water tank. It is found that 250 mL of water can be cooled from 18.5°C to 13°C, where the corresponding coefficient of performance (COP is changed between 0.55 and 1.05, when solar insolation is changed between 450 W/m2 and 1000 W/m2. The experimental results demonstrate that the thermoelectric chiller driven by solar cell is feasible and effective for energy saving issues.

  4. Practical antireflection coatings for metal-semiconductor solar cells

    Science.gov (United States)

    Yeh, Y. C. M.; Ernest, F. P.; Stirn, R. J.

    1976-01-01

    The metal-semiconductor solar cell is a potential candidate for converting solar energy to electrical energy for space and terrestrial application. In this paper, a method for obtaining parameters of practical antireflection (AR) coatings for the metal-semiconductor solar cells is given. This method utilizes the measured equivalent index of refraction obtained from ellipsometry, since the surface to be AR coated has a multilayer structure. Both the experimental results and theoretical calculations of optical parameters for Ta2O5 AR coatings on Au-GaAs and Au-GaAs(0.78)P(0.22) solar cells are presented for comparison.

  5. Practical anti-reflection coating for metal semiconductor solar cells

    Science.gov (United States)

    Yeh, Y.-C. M.; Stirn, R. J.

    1975-01-01

    The metal-semiconductor solar cell is a possible candidate for converting solar to electrical energy for terrestrial application. A method is given for obtaining optical parameters of practical antireflection coatings for the metal-semiconductor solar cell. This method utilizes the measured refractive index obtained from ellipsometry since the surface to be AR coated has a multilayer structure. Both the experimental results and theoretical calculation of optical parameters for Ta2O5 antireflection coatings on Au-GaAs and Au-GaAs(0.78)P(0.22) solar cells are presented for comparison.

  6. Review of Polymer, Dye-Sensitized, and Hybrid Solar Cells

    Directory of Open Access Journals (Sweden)

    S. N. F. Mohd-Nasir

    2014-01-01

    Full Text Available The combination of inorganic nanoparticles semiconductor, conjugated polymer, and dye-sensitized in a layer of solar cell is now recognized as potential application in developing flexible, large area, and low cost photovoltaic devices. Several conjugated low bandgap polymers, dyes, and underlayer materials based on the previous studies are quoted in this paper, which can provide guidelines in designing low cost photovoltaic solar cells. All of these materials are designed to help harvest more sunlight in a wider range of the solar spectrum besides enhancing the rate of charge transfer in a device structure. This review focuses on developing solid-state dye-synthesized, polymer, and hybrid solar cells.

  7. Cadmium Alternatives

    Science.gov (United States)

    2012-08-01

    using for commercial applications Other zinc alloys Zinc cobalt , tin zinc, zinc iron Passivation Cadmium, ZnNi, SnZn, ZnCo, ZnFe, and...for Change Cadmium passivated with hexavalent chromium has been in use for many decades Cadmium is toxic, and is classified as a priority...Executive Orders 13514 & 13423 DoD initiatives – Young memo (April 2009) DFAR restricting use of hexavalent chromium Allows the use of hexavalent

  8. Dip coated nanocrystalline CdZnS thin films for solar cell application

    Energy Technology Data Exchange (ETDEWEB)

    Dongre, J. K., E-mail: jk-dongre@yahoo.com; Chaturvedi, Mahim; Patil, Yuvraj; Sharma, Sandhya; Jain, U. K. [Government Autonomous Post Graduate College Chhindwara, 480001 (India)

    2015-07-31

    Nanocrystalline cadmium sulfide (CdS) and zinc cadmium sulfide (ZnCdS) thin films have been grown via simple and low cost dip coating technique. The prepared films are characterized by X-ray diffraction (XRD), atomic force microscopic (AFM) and UV-VIS spectrophotometer techniques to reveal their structural, morphological and optical properties. XRD shows that both samples grown have zinc blende structure. The grain size is calculated as 6.2 and 8 nm using Scherrer’s formula. The band gap value of CdS and CdZnS film is estimated to be 2.58 and 2.69 eV respectively by UV-vis spectroscopy. Photoelectrochemical (PEC) investigations are carried out using cell configuration as n-CdZnS/(1M NaOH + 1M Na2S + 1M S)/C. The photovoltaic output characteristic is used to calculate fill-factor (FF) and solar conversion efficiency (η)

  9. Exogenous auxin alleviates cadmium toxicity in Arabidopsis thaliana by stimulating synthesis of hemicellulose 1 and increasing the cadmium fixation capacity of root cell walls

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Xiao Fang [Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education, College of Life Sciences, Zhejiang University, Hangzhou 310058 (China); State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058 (China); Wang, Zhi Wei [Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education, College of Life Sciences, Zhejiang University, Hangzhou 310058 (China); Dong, Fang; Lei, Gui Jie [State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058 (China); Shi, Yuan Zhi [The Key Laboratory of Tea Chemical Engineering, Ministry of Agriculture, Yunqi Road 1, Hangzhou 310008 (China); Li, Gui Xin, E-mail: guixinli@zju.edu.cn [College of Agronomy and Biotechnology, Zhejiang University, Hangzhou 310058 (China); Zheng, Shao Jian [Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education, College of Life Sciences, Zhejiang University, Hangzhou 310058 (China); State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058 (China)

    2013-12-15

    Highlights: • Cd reduces endogenous auxin levels in Arabidopsis. • Exogenous applied auxin NAA increases Cd accumulation in the roots but decreases in the shoots. • NAA increases cell wall hemicellulose 1 content. • Hemicellulose 1 retains Cd and makes it difficult to be translocated to shoots. • NAA rescues Cd-induced chlorosis. -- Abstract: Auxin is involved in not only plant physiological and developmental processes but also plant responses to abiotic stresses. In this study, cadmium (Cd{sup 2+}) stress decreased the endogenous auxin level, whereas exogenous auxin (α-naphthaleneacetic acid, NAA, a permeable auxin analog) reduced shoot Cd{sup 2+} concentration and rescued Cd{sup 2+}-induced chlorosis in Arabidopsis thaliana. Under Cd{sup 2+} stress conditions, NAA increased Cd{sup 2+} retention in the roots and most Cd{sup 2+} in the roots was fixed in hemicellulose 1 of the cell wall. NAA treatment did not affect pectin content and its binding capacity for Cd{sup 2+}, whereas it significantly increased the content of hemicellulose 1 and the amount of Cd{sup 2+} retained in it. There were highly significant correlations between Cd{sup 2+} concentrations in the root, cell wall and hemicellulose 1 when the plants were subjected to Cd{sup 2+} or NAA + Cd{sup 2+} treatment for 1 to 7 d, suggesting that the increase in hemicellulose 1 contributes greatly to the fixation of Cd{sup 2+} in the cell wall. Taken together, these results demonstrate that auxin-induced alleviation of Cd{sup 2+} toxicity in Arabidopsis is mediated through increasing hemicellulose 1 content and Cd{sup 2+} fixation in the root, thus reducing the translocation of Cd{sup 2+} from roots to shoots.

  10. Electron Acceptor Materials Engineering in Colloidal Quantum Dot Solar Cells

    KAUST Repository

    Liu, Huan

    2011-07-15

    Lead sulfide colloidal quantum dot (CQD) solar cells with a solar power conversion efficiency of 5.6% are reported. The result is achieved through careful optimization of the titanium dioxide electrode that serves as the electron acceptor. Metal-ion-doped sol-gel-derived titanium dioxide electrodes produce a tunable-bandedge, well-passivated materials platform for CQD solar cell optimization. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Solar cells as a renewable source for electricity generation

    OpenAIRE

    Mezek, Maksimilijan

    2017-01-01

    Thesis is dedicated to in-service primary school technology teachers. The operation of solar cells is described first, then a history, followed by the direction of the development of solar cells. The next part of the thesis compare generation of electricity with various power plants in relation to the environment. There is also described some photovoltaic systems and what are the possibilities of obtaining solar energy. Project-based learning characteristics, types and phases are presente...

  12. The role of intracellular oxidation in death induction (apoptosis and necrosis) in human promonocytic cells treated with stress inducers (cadmium, heat, X-rays).

    Science.gov (United States)

    Galán, A; García-Bermejo, L; Troyano, A; Vilaboa, N E; Fernández, C; de Blas, E; Aller, P

    2001-04-01

    Treatment of U-937 human promonocytic cells with the stress inducers cadmium chloride (2 h at 200 microM), heat (2 h at 42.5 C) or X-rays (20 Gy), followed by recovery, caused death by apoptosis and stimulated caspase-3 activity. In addition, all stress agents caused intracellular oxidation, as measured by peroxide and/or anion superoxide accumulation. However, while pre-incubation with antioxidants (N-acetyl-L-cysteine or butylated hydroxyanisole) inhibited the induction of apoptosis by cadmium and X-rays, it did not affect the induction by heat-shock. Pre-incubation for 24 h with the GSH-depleting agent L-buthionine-[S,R]-sulfoximine (BSO) switched the mode of death from apoptosis to necrosis in cadmium-treated cells. By contrast, BSO only caused minor modifacions in the rate of apoptosis without affecting the mode of death in heat- and X-rays-treated cells. BSO potentiated peroxide accumulation in cells treated with both cadmium and X-rays. However, while the accumulation of peroxides was stable in the case of cadmium, it was transient in the case of X-rays. Moreover, the administration of antioxidants during the recovery period sufficed to prevent necrosis and restore apoptosis in BSO plus cadmium-treated cells. Cadmium and X-rays caused a decrease in intracellular ATP levels, but the decrease was similar in both apoptotic and necrotic cells. Taken together, these results demonstrate that (i) stress inducers cause intracellular oxidation, but oxidation is not a general requirement for apoptosis; and (ii) the duration of the oxidant state seems to be critical in determining the mode of death.

  13. Cytocompatibility of direct water synthesized cadmium selenide quantum dots in colo-205 cells

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Torres, Marcos R. [Universidad Metropolitana, Nanomaterials Science Laboratory, School of Science and Technology (United States); Velez, Christian; Zayas, Beatriz [Universidad Metropolitana, ChemTox Laboratory, School of Environmental Affairs (United States); Rivera, Osvaldo [Universidad Metropolitana, Nanomaterials Science Laboratory, School of Science and Technology (United States); Arslan, Zikri [Jackson State University, Department of Chemistry (United States); Gonzalez-Vega, Maxine N. [Universidad Metropolitana, Nanomaterials Science Laboratory, School of Science and Technology (United States); Diaz-Diestra, Daysi; Beltran-Huarac, Juan; Morell, Gerardo [University of Puerto Rico, Molecular Science Research Center (United States); Primera-Pedrozo, Oliva M., E-mail: oprimera1@suagm.edu [Universidad Metropolitana, Nanomaterials Science Laboratory, School of Science and Technology (United States)

    2015-06-15

    Cadmium selenide quantum dots (CdSe QDs), inorganic semiconducting nanocrystals, are alluring increased attraction due to their highly refined chemistry, availability, and super tunable optical properties suitable for many applications in different research areas, such as photovoltaics, light-emitting devices, environmental sciences, and nanomedicine. Specifically, they are being widely used in bio-imaging in contrast to organic dyes due to their high brightness and improved photo-stability, and their ability to tune their absorption and emission spectra upon changing the crystal size. The production of CdSe QDs is mostly assisted by trioctylphosphine oxide compound, which acts as solvent or solubilizing agent and renders the QDs soluble in organic compounds (such as toluene, chloroform, and hexane) that are highly toxic. To circumvent the toxicity-related factor in CdSe QDs, we report the synthesis of CdSe QDs capped with thioglycolic acid (TGA) in an aqueous medium, and their biocompatibility in colo-205 cancer cells. In this study, the [Cd{sup 2+}]/[TGA] ratio was adjusted to 11:1 and the Se concentration (10 and 15 mM) was monitored in order to evaluate its influence on the optical properties and cytocompatibility. QDs resulted to be quite stable in water (after purification) and RPMI cell medium and no precipitation was observed for long contact times, making them appealing for in vitro experiments. The spectroscopy analysis, advanced electron microscopy, and X-ray diffractometry studies indicate that the final products were successfully formed exhibiting an improved optical response. Colo-205 cells being exposed to different concentrations of TGA-capped CdSe QDs for 12, 24, and 48 h with doses ranging from 0.5 to 2.0 mM show high tolerance reaching cell viabilities as high as 93 %. No evidence of cellular apoptotic pathways was observed as pointed out by our Annexin V assays at higher concentrations. Moreover, confocal microscopy analysis conducted to

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-02-01

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

  15. Experiment Based Teaching of Solar Cell Operation and Characterization Using the SolarLab Platform

    DEFF Research Database (Denmark)

    Spataru, Sergiu; Sera, Dezso; Kerekes, Tamas

    2014-01-01

    Experiment based teaching methods are a great way to get students involved and interested in almost any topic. This paper presents such a hands-on approach for teaching solar cell operation principles along with characterization and modelling methods. This is achieved with the SolarLab platform...... interfaces for exploring different solar cell principles and topics. The exercises presented in the current paper have been adapted from the original exercises developed for the SolarLab platform and are currently included in the Photovoltaic Power Systems courses (MSc and PhD level) taught at the Department...

  16. Thin Crystalline Gallium Arsenide Optoelectronic Devices

    Science.gov (United States)

    Patkar, Mahesh Pandharinath

    1995-01-01

    The numerous existing and developing applications for two closely related devices, III-V light emitting diode (LEDs) and solar cells, demand improved device efficiencies. Removing the substrate should increase the efficiency of both LEDs and solar cells by eliminating the absorption losses in the substrate. We have used the phenomenon of photon recycling in thin-crystalline device geometries to enhance efficiencies of LEDs and solar cells. GaAs LEDs were fabricated and removed from the substrate by the epitaxial lift-off process. Devices with and without an underlying GaAs substrate were then characterized by optical and electrical measurements. Efficiency enhancements of up to a factor of six were achieved. By carefully analyzing the electrical and optical measurements, we demonstrate that the device operation can be explained in terms of accepted theories for radiative recombination and photon recycling which supports our hypothesis that the efficiency enhancement is due to photon recycling in the thin-crystalline device structure. Electrical and optical characterization of ELO LEDs is also shown to be a convenient diagnostic tool for examining recombination losses in thin-crystalline solar cells. Thin crystalline solar cells were fabricated and characterized by I-V and QE measurements. Alloyed ohmic contacts are used extensively for GaAs devices. However, alloyed contacts produce rough interfaces that do not make good reflectors needed for many optoelectronic devices. Non-alloyed ohmic contacts to optoelectronic devices could make good reflectors, if one uses highly reflective metal like Au to make an ohmic contact. Ex-situ non-alloyed contacts to n-GaAs were made by using low temperature molecular beam epitaxy. Ag and Ti/Au contacts to this structure exhibited specific contact resistivities of mid 10^{-7} Omega-cm^2. Low temperature molecular beam epitaxy of GaAs with high concentrations of Be followed by an anneal under As over pressure was used to minimize

  17. Topology optimization of front metallization patterns for solar cells

    NARCIS (Netherlands)

    Gupta, D.K.; Langelaar, M.; Barink, M.; Keulen, F. van

    2015-01-01

    This paper presents the application of topology optimization (TO) for designing the front electrode patterns for solar cells. Improving the front electrode design is one of the approaches to improve the performance of the solar cells. It serves to produce the voltage distribution for the front

  18. Transparent conductive oxides for thin-film silicon solar cells

    NARCIS (Netherlands)

    Löffler, J.

    2005-01-01

    This thesis describes research on thin-film silicon solar cells with focus on the transparent conductive oxide (TCO) for such devices. In addition to the formation of a transparent and electrically conductive front electrode for the solar cell allowing photocurrent collection with low ohmic losses,

  19. Microstructure and Mechanical Aspects of Multicrystalline Silicon Solar Cells

    NARCIS (Netherlands)

    Popovich, V.A.

    2013-01-01

    Due to pressure from the photovoltaic industry to decrease the cost of solar cell production, there is a tendency to reduce the thickness of silicon wafers. Unfortunately, wafers contain defects created by the various processing steps involved in solar cell production, which significantly reduce the

  20. Improvement of multicrystalline silicon wafer solar cells by post ...

    Indian Academy of Sciences (India)

    ) and the fill factor (FF) of finished multicrystalline silicon (-Si) solar cells by using a new chemical treatment with a hot phosphoric (H3PO4) acidic solution. These -Si solar cells were made by a standard industrial process with ...

  1. 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...

  2. Applications of ``PV Optics`` for solar cell and module design

    Energy Technology Data Exchange (ETDEWEB)

    Sopori, B.L.; Madjdpour, J.; Chen, W. [National Renewable Energy Lab., Golden, CO (United States)

    1998-09-01

    This paper describes some applications of a new optics software package, PV Optics, developed for the optical design of solar cells and modules. PV Optics is suitable for the analysis and design of both thick and thin solar cells. It also includes a feature for calculation of metallic losses related to contacts and back reflectors.

  3. The appropriateness of organic solar cells for indoor lighting conditions

    Science.gov (United States)

    Minnaert, B.; Veelaert, P.

    2010-05-01

    Most commercially available photovoltaic solar cells are crystalline silicon cells. However, in indoor environments, the efficiency of silicon solar cells is poor. Typically, the light intensity under artificial lighting conditions is less than 10 W/m2 as compared to 100-1000 W/m2 under outdoor conditions. Moreover, the spectrum is different from the outdoor solar spectrum and there is more diffuse than direct light. Taken into account the predicted cheaper costs for the production of organic solar cells, a possible niche market for organic PV can be indoor applications. In this article, we study the influence of the narrow absorption window, characteristic for organic solar cells, for different indoor conditions. This comparison is made for typical artificial light sources, i.e. a common incandescent lamp, an LED lamp and a "warm" and a "cool" fluorescent tube, which are compared to the outdoor AM 1.5 spectrum as reference. The comparisons are done by simulation based on the quantum efficiencies of the solar cells and the light spectra of the different light sources. A classical silicon solar cell is used as reference. In this way we determine the appropriateness for indoor use of organic solar cells.

  4. Stability and degradation mechanisms in organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Ecker, Bernhard

    2012-04-26

    This thesis deals with stability improvements and the investigation of degradation mechanisms in organic solar cells. Organic solar cells have been in the focus of extensive academic research for over almost two decades and are currently entering the market in small scale applications. For successful large scale applications, next to the improvement of the power conversion efficiency, the stability of organic solar cells has to be increased. This thesis is dedicated to the investigation of novel materials and architectures to study stability-related issues and degradation mechanisms in order to contribute to the basic understanding of the working principles of organic solar cells. Here, impedance spectroscopy, a frequency domain technique, is used to gain information about stability and degradation mechanisms in organic solar cells. In combination with systematic variations in the preparation of solar cells, impedance spectroscopy gives the possibility to differentiate between interface and bulk dominated effects. Additionally, impedance spectroscopy gives access to the dielectric properties of the device, such as capacitance. This offers among other things the opportunity to probe the charge carrier concentration and the density of states. Another powerful way of evaluation is the combination of experimentally obtained impedance spectra with equivalent circuit modelling. The thesis presents results on novel materials and solar cell architectures for efficient hole and electron extraction. This indicates the importance of knowledge over interlayers and interfaces for improving both the efficiency and stability of organic solar cells.

  5. Inkjet printing of back electrodes for inverted polymer solar cells

    NARCIS (Netherlands)

    Angmo, D.; Sweelssen, J.; Andriessen, H.A.J.M.; Galagan, Y.O.; Krebs, F.C.

    2013-01-01

    Evaporation is the most commonly used deposition method in the processing of back electrodes in polymer solar cells used in scientifi c studies. However, vacuum-based methods such as evaporation are uneconomical in the upscaling of polymer solar cells as they are throughput limiting steps in an

  6. Amorphous and crystalline silicon based heterojunction solar cells

    NARCIS (Netherlands)

    Schuttauf, J.A.|info:eu-repo/dai/nl/314118039

    2011-01-01

    In this thesis, research on amorphous and crystalline silicon heterojunction (SHJ) solar cells is described. Probably the most important feature of SHJ solar cells is a thin intrinsic amorphous silicion (a‑Si:H) layer that is deposited before depositing the doped emitter and back surface field. The

  7. Pathways to a New Efficiency Regime for Organic Solar Cells

    NARCIS (Netherlands)

    Koster, L. Jan Anton; Shaheen, Sean E.; Hummelen, Jan C.

    2012-01-01

    Three different theoretical approaches are presented to identify pathways to organic solar cells with power conversion efficiencies in excess of 20%. A radiation limit for organic solar cells is introduced that elucidates the role of charge-transfer (CT) state absorption. Provided this CT action is

  8. Solar cell is housed in light-bulb enclosure

    Science.gov (United States)

    Evans, J. C., Jr.

    1981-01-01

    Inexpensive, conventional solar-cell module uses focusing principle of electric lamp in reverse to produce electric power from sunlight. Standard outdoor light enclosure provides low-cost housing which concentrates sunlight in solar cell. Unit is capable of producing approximately 1 watt of electric power.

  9. Device physics of polymer : fullerene bulk heterojunction solar cells

    NARCIS (Netherlands)

    Blom, Paul W. M.; Mihailetchi, Valentin D.; Koster, L. Jan Anton; Markov, Denis E.

    2007-01-01

    Plastic solar cells bear the potential for large-scale power generation based on materials that provide the possibility of flexible, lightweight, inexpensive, efficient solar cells. Since the discovery of the photoinduced electron transfer from a conjugated polymer to fullerene molecules, followed

  10. Topology optimization for improving the performance of solar cells

    NARCIS (Netherlands)

    Gupta, D.K.; Langelaar, M.; Keulen, F. van; Barink, M.

    2014-01-01

    This work introduces the application of Topology Optimization (TO) to design optimal front metallization patterns for solar cells and increase their power output. A challenging aspect of the solar cell electrode design problem is the strong nonlinear relation between the active layer current and the

  11. Evaluation of solar cells and arrays for potential solar power satellite applications. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Almgren, D.W.; Csigi, K.; Gaudet, A.D.

    1978-03-31

    Proposed solar array designs and manufacturing methods are evaluated to identify options which show the greatest promise of leading up to the develpment of a cost-effective SPS solar cell array design. The key program elements which have to be accomplished as part of an SPS solar cell array development program are defined. The issues focussed on are: (1) definition of one or more designs of a candidate SPS solar array module, using results from current system studies; (2) development of the necessary manufacturing requirements for the candidate SPS solar cell arrays and an assessment of the market size, timing, and industry infrastructure needed to produce the arrays for the SPS program; (3) evaluation of current DOE, NASA and DOD photovoltaic programs to determine the impacts of recent advances in solar cell materials, array designs and manufacturing technology on the candidate SPS solar cell arrays; and (4) definition of key program elements for the development of the most promising solar cell arrays for the SPS program.

  12. Evaluation of solar cells and arrays for potential solar power satellite applications

    Science.gov (United States)

    Almgren, D. W.; Csigi, K.; Gaudet, A. D.

    1978-01-01

    Proposed solar array designs and manufacturing methods are evaluated to identify options which show the greatest promise of leading up to the develpment of a cost-effective SPS solar cell array design. The key program elements which have to be accomplished as part of an SPS solar cell array development program are defined. The issues focussed on are: (1) definition of one or more designs of a candidate SPS solar array module, using results from current system studies; (2) development of the necessary manufacturing requirements for the candidate SPS solar cell arrays and an assessment of the market size, timing, and industry infrastructure needed to produce the arrays for the SPS program; (3) evaluation of current DOE, NASA and DOD photovoltaic programs to determine the impacts of recent advances in solar cell materials, array designs and manufacturing technology on the candidate SPS solar cell arrays; and (4) definition of key program elements for the development of the most promising solar cell arrays for the SPS program.

  13. Silicon Thin-Film Solar Cells

    Directory of Open Access Journals (Sweden)

    Guy Beaucarne

    2007-01-01

    with plasma-enhanced chemical vapor deposition (PECVD. In spite of the fundamental limitation of this material due to its disorder and metastability, the technology is now gaining industrial momentum thanks to the entry of equipment manufacturers with experience with large-area PECVD. Microcrystalline Si (also called nanocrystalline Si is a material with crystallites in the nanometer range in an amorphous matrix, and which contains less defects than amorphous silicon. Its lower bandgap makes it particularly appropriate as active material for the bottom cell in tandem and triple junction devices. The combination of an amorphous silicon top cell and a microcrystalline bottom cell has yielded promising results, but much work is needed to implement it on large-area and to limit light-induced degradation. Finally thin-film polysilicon solar cells, with grain size in the micrometer range, has recently emerged as an alternative photovoltaic technology. The layers have a grain size ranging from 1 μm to several tens of microns, and are formed at a temperature ranging from 600 to more than 1000∘C. Solid Phase Crystallization has yielded the best results so far but there has recently been fast progress with seed layer approaches, particularly those using the aluminum-induced crystallization technique.

  14. Monolithic Perovskite Silicon Tandem Solar Cells with Advanced Optics

    Energy Technology Data Exchange (ETDEWEB)

    Goldschmidt, Jan C.; Bett, Alexander J.; Bivour, Martin; Blasi, Benedikt; Eisenlohr, Johannes; Kohlstadt, Markus; Lee, Seunghun; Mastroianni, Simone; Mundt, Laura; Mundus, Markus; Ndione, Paul; Reichel, Christian; Schubert, Martin; Schulze, Patricia S.; Tucher, Nico; Veit, Clemens; Veurman, Welmoed; Wienands, Karl; Winkler, Kristina; Wurfel, Uli; Glunz, Stefan W.; Hermle, Martin

    2016-11-14

    For high efficiency monolithic perovskite silicon tandem solar cells, we develop low-temperature processes for the perovskite top cell, rear-side light trapping, optimized perovskite growth, transparent contacts and adapted characterization methods.

  15. Environmentally benign silicon solar cell manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Tsuo, Y.S. [National Renewable Energy Lab., Golden, CO (United States); Gee, J.M. [Sandia National Labs., Albuquerque, NM (United States); Menna, P. [National Agency for New Technologies Energy and Environment, Portici (Italy); Strebkov, D.S.; Pinov, A.; Zadde, V. [Intersolarcenter, Moscow (Russian Federation)

    1998-09-01

    The manufacturing of silicon devices--from polysilicon production, crystal growth, ingot slicing, wafer cleaning, device processing, to encapsulation--requires many steps that are energy intensive and use large amounts of water and toxic chemicals. In the past two years, the silicon integrated-circuit (IC) industry has initiated several programs to promote environmentally benign manufacturing, i.e., manufacturing practices that recover, recycle, and reuse materials resources with a minimal consumption of energy. Crystalline-silicon solar photovoltaic (PV) modules, which accounted for 87% of the worldwide module shipments in 1997, are large-area devices with many manufacturing steps similar to those used in the IC industry. Obviously, there are significant opportunities for the PV industry to implement more environmentally benign manufacturing approaches. Such approaches often have the potential for significant cost reduction by reducing energy use and/or the purchase volume of new chemicals and by cutting the amount of used chemicals that must be discarded. This paper will review recent accomplishments of the IC industry initiatives and discuss new processes for environmentally benign silicon solar-cell manufacturing.

  16. Modelling of the modulation properties of arsenide and nitride VCSELs

    Science.gov (United States)

    Wasiak, Michał; Śpiewak, Patrycja; Moser, Philip; Gebski, Marcin; Schmeckebier, Holger; Sarzała, Robert P.; Lott, James A.

    2017-02-01

    In this paper, using our model of capacitance in vertical-cavity surface-emitting lasers (VCSELs), we analyze certain differences between an oxide-confined arsenide VCSEL emitting in the NIR region, and a nitride VCSEL emitting violet radiation. In the nitride laser its high differential resistance, caused partially by the low conductivity of p-type GaN material and the bottom contact configuration, is one of the main reasons why the nitride VCSEL has much worse modulation properties than the arsenide VCSEL. Using the complicated arsenide structure, we also analyze different possible ways of constructing the laser's equivalent circuit.

  17. Photoelectrochemistry of metallo-octacarboxyphthalocyanines for the development of dye solar cells

    CSIR Research Space (South Africa)

    Mphahlele, N

    2011-09-01

    Full Text Available Significant attention is being paid to dye solar cells (DSCs) as the next generation in solar cell technology for their low cost alternative as compared to solid state solar cells....

  18. Oxidative injury induced by cadmium sulfide nanoparticles in A549 cells and rat lungs.

    Science.gov (United States)

    Wang, Junfeng; Jiang, Chunyang; Alattar, Mohamed; Hu, Xiaoli; Ma, Dong; Liu, Huibin; Meng, Chunyan; Cao, Fuyuan; Li, Weihong; Li, Qingzhao

    2015-01-01

    Rod-shaped cadmium sulfide nanoparticles (CdS NPs) are becoming increasingly important in many industrial fields, but their potential hazards remain unknown. This study aimed to explore the patterns and mechanisms of lung injury induced by CdS NPs. A549 cells and rats were exposed to two types of CdS NPs with a same diameter of 20-30 nm but different lengths, CdS1 (80-100 nm) and CdS2 (110-130 nm). The using doses were included 10 μg/ml and 20 μg/ml two types of CdS NPs for cellular experiments and five times dose of 20 mg/kg body weight for rats' exposure. Methylthiazolyldiphenyl-tetrazolium bromide (MTT) and trypan blue staining were used to detect the A549 cell mortality percentage. The levels of reactive oxygen species (ROS) were determined in A549 cell. The vigor of superoxide dismutase (SOD) and the contents of catalase (CAT) and malondialdehyde (MDA) were detected both in A549 cells and in rats' serum and lung tissues. The cellular morphological changes were observed under transmission electron microscopy (TEM) and the pathological changes were observed in rats' lung tissue. CdS NPs significantly increased A549 cell mortality percentage. The CdS NPs also increased the levels of ROS and MDA content, whereas they decreased SOD and CAT activities. In parallel, similar changes of the contents of MDA, SOD and CAT were also observed in the sera and lung tissues of CdS NP-treated rats. The cellular TEM detection revealed that two types of CdS nanorods appeared as orderly arranged rounded fat droplets separately and leading to nucleus condensation (CdS1). These cellular and rats' tissues changes in the group treated with CdS1 were more significant than the CdS2 groups. Furthermore, CdS NPs induced many pathological changes, including emphysematous changes in rat lung tissue. Especially visible lung consolidation can be observed in the CdS1 group. CdS NPs induce oxidative injury in the respiratory system, and their toxic effects may be related to grain length.

  19. Cooling performance of solar cell driven, thermoelectric cooling prototype headgear

    Energy Technology Data Exchange (ETDEWEB)

    Hara, T.; Azuma, H.; Shimizu, H.; Obora, H.; Sato, S. [Nippon Inst. of Technology, Saitama (Japan). Dept. of Systems Engineering

    1998-11-01

    Cooling performance of solar cell-driven, thermoelectric cooling prototype headgear was examined experimentally. Three types of prototype headgear were made and examined. They were cooled by thermoelectric elements and driven by solar cells. Conventional cooling caps driven by solar cells only blow ambient air to the face with an electric fan. A thermoelectric element was set at the front of the headgear to cool the forehead. Solar cells were mounted on the top and the brim of the headgear to work the thermoelectric element. Three prototypes of headgear with solar cells and a thermoelectric element were made and tested. Refrigeration capacity and thermal comfort were examined by subject in cases of sitting, walking and bicycling. The temperature difference between ambient and cooling temperature was required to be 4-5 degrees Celsius for thermal comfort. (author)

  20. Neutral- and Multi-Colored Semitransparent Perovskite Solar Cells

    Directory of Open Access Journals (Sweden)

    Kyu-Tae Lee

    2016-04-01

    Full Text Available In this review, we summarize recent works on perovskite solar cells with neutral- and multi-colored semitransparency for building-integrated photovoltaics and tandem solar cells. The perovskite solar cells exploiting microstructured arrays of perovskite “islands” and transparent electrodes—the latter of which include thin metallic films, metal nanowires, carbon nanotubes, graphenes, and transparent conductive oxides for achieving optical transparency—are investigated. Moreover, the perovskite solar cells with distinctive color generation, which are enabled by engineering the band gap of the perovskite light-harvesting semiconductors with chemical management and integrating with photonic nanostructures, including microcavity, are discussed. We conclude by providing future research directions toward further performance improvements of the semitransparent perovskite solar cells.

  1. Near-field electromagnetic theory for thin solar cells.

    Science.gov (United States)

    Niv, A; Gharghi, M; Gladden, C; Miller, O D; Zhang, X

    2012-09-28

    Current methods for evaluating solar cell efficiencies cannot be applied to low-dimensional structures where phenomena from the realm of near-field optics prevail. We present a theoretical approach to analyze solar cell performance by allowing rigorous electromagnetic calculations of the emission rate using the fluctuation-dissipation theorem. Our approach shows the direct quantification of the voltage, current, and efficiency of low-dimensional solar cells. This approach is demonstrated by calculating the voltage and the efficiency of a GaAs slab solar cell for thicknesses from several microns down to a few nanometers. This example highlights the ability of the proposed approach to capture the role of optical near-field effects in solar cell performance.

  2. Emerging Semitransparent Solar Cells: Materials and Device Design.

    Science.gov (United States)

    Tai, Qidong; Yan, Feng

    2017-09-01

    Semitransparent solar cells can provide not only efficient power-generation but also appealing images and show promising applications in building integrated photovoltaics, wearable electronics, photovoltaic vehicles and so forth in the future. Such devices have been successfully realized by incorporating transparent electrodes in new generation low-cost solar cells, including organic solar cells (OSCs), dye-sensitized solar cells (DSCs) and organometal halide perovskite solar cells (PSCs). In this review, the advances in the preparation of semitransparent OSCs, DSCs, and PSCs are summarized, focusing on the top transparent electrode materials and device designs, which are all crucial to the performance of these devices. Techniques for optimizing the efficiency, color and transparency of the devices are addressed in detail. Finally, a summary of the research field and an outlook into the future development in this area are provided. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Neutral- and Multi-Colored Semitransparent Perovskite Solar Cells.

    Science.gov (United States)

    Lee, Kyu-Tae; Guo, L Jay; Park, Hui Joon

    2016-04-11

    In this review, we summarize recent works on perovskite solar cells with neutral- and multi-colored semitransparency for building-integrated photovoltaics and tandem solar cells. The perovskite solar cells exploiting microstructured arrays of perovskite "islands" and transparent electrodes-the latter of which include thin metallic films, metal nanowires, carbon nanotubes, graphenes, and transparent conductive oxides for achieving optical transparency-are investigated. Moreover, the perovskite solar cells with distinctive color generation, which are enabled by engineering the band gap of the perovskite light-harvesting semiconductors with chemical management and integrating with photonic nanostructures, including microcavity, are discussed. We conclude by providing future research directions toward further performance improvements of the semitransparent perovskite solar cells.

  4. 23.6%-efficient monolithic perovskite/silicon tandem solar cells with improved stability

    Science.gov (United States)

    Bush, Kevin A.; Palmstrom, Axel F.; Yu, Zhengshan J.; Boccard, Mathieu; Cheacharoen, Rongrong; Mailoa, Jonathan P.; McMeekin, David P.; Hoye, Robert L. Z.; Bailie, Colin D.; Leijtens, Tomas; Peters, Ian Marius; Minichetti, Maxmillian C.; Rolston, Nicholas; Prasanna, Rohit; Sofia, Sarah; Harwood, Duncan; Ma, Wen; Moghadam, Farhad; Snaith, Henry J.; Buonassisi, Tonio; Holman, Zachary C.; Bent, Stacey F.; McGehee, Michael D.

    2017-02-01

    As the record single-junction efficiencies of perovskite solar cells now rival those of copper indium gallium selenide, cadmium telluride and multicrystalline silicon, they are becoming increasingly attractive for use in tandem solar cells due to their wide, tunable bandgap and solution processability. Previously, perovskite/silicon tandems were limited by significant parasitic absorption and poor environmental stability. Here, we improve the efficiency of monolithic, two-terminal, 1-cm2 perovskite/silicon tandems to 23.6% by combining an infrared-tuned silicon heterojunction bottom cell with the recently developed caesium formamidinium lead halide perovskite. This more-stable perovskite tolerates deposition of a tin oxide buffer layer via atomic layer deposition that prevents shunts, has negligible parasitic absorption, and allows for the sputter deposition of a transparent top electrode. Furthermore, the window layer doubles as a diffusion barrier, increasing the thermal and environmental stability to enable perovskite devices that withstand a 1,000-hour damp heat test at 85 ∘C and 85% relative humidity.

  5. Fabrication of CdS/CdTe-Based Thin Film Solar Cells Using an Electrochemical Technique

    Directory of Open Access Journals (Sweden)

    I. M. Dharmadasa

    2014-06-01

    Full Text Available Thin film solar cells based on cadmium telluride (CdTe are complex devices which have great potential for achieving high conversion efficiencies. Lack of understanding in materials issues and device physics slows down the rapid progress of these devices. This paper combines relevant results from the literature with new results from a research programme based on electro-plated CdS and CdTe. A wide range of analytical techniques was used to investigate the materials and device structures. It has been experimentally found that n-, i- and p-type CdTe can be grown easily by electroplating. These material layers consist of nano- and micro-rod type or columnar type grains, growing normal to the substrate. Stoichiometric materials exhibit the highest crystallinity and resistivity, and layers grown closer to these conditions show n → p or p → n conversion upon heat treatment. The general trend of CdCl2 treatment is to gradually change the CdTe material’s n-type electrical property towards i-type or p-type conduction. This work also identifies a rapid structural transition of CdTe layer at 385 ± 5 °C and a slow structural transition at higher temperatures when annealed or grown at high temperature. The second transition occurs after 430 °C and requires more work to understand this gradual transition. This work also identifies the existence of two different solar cell configurations for CdS/CdTe which creates a complex situation. Finally, the paper presents the way forward with next generation CdTe-based solar cells utilising low-cost materials in their columnar nature in graded bandgap structures. These devices could absorb UV, visible and IR radiation from the solar spectrum and combine impact ionisation and impurity photovoltaic (PV effect as well as making use of IR photons from the surroundings when fully optimised.

  6. Synthesis, characterization and toxicological evaluation of maltodextrin capped cadmium sulfide nanoparticles in human cell lines and chicken embryos

    Directory of Open Access Journals (Sweden)

    Rodríguez-Fragoso Patricia

    2012-12-01

    Full Text Available Abstract Background Semiconductor Quantum dots (QDs have become quite popular thanks to their properties and wide use in biological and biomedical studies. However, these same properties entail new challenges in understanding, predicting, and managing potential adverse health effects following exposure. Cadmium and selenium, which are the major components of the majority of quantum dots, are known to be acutely and chronically toxic to cells and organisms. Protecting the core of nanoparticles can, to some degree, control the toxicity related to cadmium and selenium leakage. Results This study successfully synthesized and characterized maltodextrin coated cadmium sulfide semiconductor nanoparticles. The results show that CdS-MD nanoparticles are cytotoxic and embryotoxic. CdS-MD nanoparticles in low concentrations (4.92 and 6.56 nM lightly increased the number of HepG2 cell. A reduction in MDA-MB-231 cells was observed with concentrations higher than 4.92 nM in a dose response manner, while Caco-2 cells showed an important increase starting at 1.64 nM. CdS-MD nanoparticles induced cell death by apoptosis and necrosis in MDA-MD-231 cells starting at 8.20 nM concentrations in a dose response manner. The exposure of these cells to 11.48-14.76 nM of CdS-MD nanoparticles induced ROS production. The analysis of cell proliferation in MDA-MB-231 showed different effects. Low concentrations (1.64 nM increased cell proliferation (6% at 7 days (p 4.92 nM increased cell proliferation in a dose response manner (15-30% at 7 days. Exposures of chicken embryos to CdS-MD nanoparticles resulted in a dose-dependent increase in anomalies that, starting at 9.84 nM, centered on the heart, central nervous system, placodes, neural tube and somites. No toxic alterations were observed with concentrations of  Conclusions Our results indicate that CdS-MD nanoparticles induce cell death and alter cell proliferation in human cell lines at concentrations higher than 4.92 n

  7. Workshop - Solar cells and daylight. Solar cell house. House building with integrated solar cell systems; Workshop - Solceller og dagslys. Solcellehus. Boligbyggeri med integrerede solcelleanlaeg

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, Mio; Hansen, Ellen Kathrine

    2005-04-15

    The workshop 'Solar cells and daylight' at Aarhus School of Architecture aimed at studying and developing architectural potentials of integrating solar cell systems in building components for future house building. The aim of the process was to stress that technical conditions such as energy technological component design might work as central points of support in the future shaping and organisation of qualitative and functional design of houses. (BA)

  8. High-voltage multijunction photovoltaic solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Doroshenko, V.G.; Zaks, M.B.; Kalash' yan, V.A.; Lozovskiy, V.N.; Skokov, Yu.V.; Solodukha, O.I.

    1979-01-01

    The possibility of developing a high-voltage multijunction photovoltaic cell (HMPC) based on a single crystal with multiple vertical p-n junctions formed by heavily doped zones at right angles to the illuminated surface of the instrument is demonstrated. A laboratory technology for producing HMPC based on the zone recrystallization method with a temperature gradient and linear zones is presented. The investigated variant of HMPC was made of n-type silicon with resistivity of 1 ohm.cm in which are formed vertical p/sup +/ type zones doped with aluminum or an aluminum-boron alloy. The performance HMPC (with 11 and 5 vertical p-n junctions) was experimentally investigated in the presence of 400 to 500 ms light pulses from a xenon lamp with a near-solar spectrum and the current-voltage characteristic of the HMPC was found to be then virtually unaffected.

  9. Core-shell silicon nanowire solar cells.

    Science.gov (United States)

    Adachi, M M; Anantram, M P; Karim, K S

    2013-01-01

    Silicon nanowires can enhance broadband optical absorption and reduce radial carrier collection distances in solar cell devices. Arrays of disordered nanowires grown by vapor-liquid-solid method are attractive because they can be grown on low-cost substrates such as glass, and are large area compatible. Here, we experimentally demonstrate that an array of disordered silicon nanowires surrounded by a thin transparent conductive oxide has both low diffuse and specular reflection with total values as low as nanowire facilitates enhancement in external quantum efficiency using two different active shell materials: amorphous silicon and nanocrystalline silicon. As a result, the core-shell nanowire device exhibits a short-circuit current enhancement of 15% with an amorphous Si shell and 26% with a nanocrystalline Si shell compared to their corresponding planar devices.

  10. Organic Charge Carriers for Perovskite Solar Cells.

    Science.gov (United States)

    Völker, Sebastian F; Collavini, Silvia; Delgado, Juan Luis

    2015-09-21

    The photovoltaic field is currently experiencing the "perovskite revolution". These materials have been known for decades, but only recently have they been applied in solid-state solar cells to obtain outstanding power conversion efficiencies. Given that the variety of perovskites used so far is limited, a lot of attention has been devoted to the development of suitable organic charge-transport materials to improve device performance. In this article, we will focus on the most promising materials able to transport electrons or holes from a structural point of view. Thereby, we focus on organic materials owing to their ease of preparation and manipulation, and this is nicely combined with the potential tuning of their properties through chemical synthesis. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Predicting efficiency of solar cells based on transparent conducting electrodes

    Science.gov (United States)

    Kumar, Ankush

    2017-01-01

    Efficiency of a solar cell is directly correlated with the performance of its transparent conducting electrodes (TCEs) which dictates its two core processes, viz., absorption and collection efficiencies. Emerging designs of a TCE involve active networks of carbon nanotubes, silver nanowires and various template-based techniques providing diverse structures; here, voids are transparent for optical transmittance while the conducting network acts as a charge collector. However, it is still not well understood as to which kind of network structure leads to an optimum solar cell performance; therefore, mostly an arbitrary network is chosen as a solar cell electrode. Herein, we propose a new generic approach for understanding the role of TCEs in determining the solar cell efficiency based on analysis of shadowing and recombination losses. A random network of wires encloses void regions of different sizes and shapes which permit light transmission; two terms, void fraction and equivalent radius, are defined to represent the TCE transmittance and wire spacings, respectively. The approach has been applied to various literature examples and their solar cell performance has been compared. To obtain high-efficiency solar cells, optimum density of the wires and their aspect ratio as well as active layer thickness are calculated. Our findings show that a TCE well suitable for one solar cell may not be suitable for another. For high diffusion length based solar cells, the void fraction of the network should be low while for low diffusion length based solar cells, the equivalent radius should be lower. The network with less wire spacing compared to the diffusion length behaves similar to continuous film based TCEs (such as indium tin oxide). The present work will be useful for architectural as well as material engineering of transparent electrodes for improvisation of solar cell performance.

  12. Toxic effects of cadmium on flatworm stem cell dynamics: A transcriptomic and ultrastructural elucidation of underlying mechanisms.

    Science.gov (United States)

    Plusquin, Michelle; De Mulder, Katrien; Van Belleghem, Frank; DeGheselle, Olivier; Pirotte, Nicky; Willems, Maxime; Cuypers, Ann; Salvenmoser, Willi; Ladurner, Peter; Artois, Tom; Smeets, Karen

    2016-10-01

    Stem cells or undifferentiated cells can cope more easily with external stresses. To evaluate the impact of toxic compounds on stem cell dynamics in vivo, in relation to other biological responses, we use the carcinogenic element cadmium and the regenerating model organism Macrostomum lignano. Through both BrdU and anti-histone H3 immunostainings, cadmium-induced effects were investigated at different stages of the stem cell cycle. A 24-h exposure to 100 and 250 μM CdCl2 significantly decreased the number of stem cells (neoblasts) in mitosis, whereas the number of cells in the S phase remained unchanged. After this short-term exposure, the ultrastructure of the neoblasts was minimally affected in contrast to the epidermal tissues. These results were supported by gene expression data: transcripts of cdc2 and pig3 were significantly upregulated during all treatments. Both genes are involved in the cell cycle progression and are transcribed in the gonadal region, where stem cells are highly represented. Based on a substantial increase in gene expression of heat shock proteins (HSP) and their high activity in the gonadal region, we hypothesize that these proteins are key players in the protection of stem cells against external stresses. Apart from the strong HSP induction, other protective processes including cell division, apoptosis and anti-oxidative defence, were also activated. We, therefore, conclude that the protection of stem cells against external stressors may be based on the interplay between stem cell maintenance, i.e. repair and recovery through division, on one hand and apoptosis on the other hand. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1217-1228, 2016. © 2015 Wiley Periodicals, Inc.

  13. Synthesis, evaluation and defect compensation of tetrahedral glasses as possible solar cell materials. Final report, February 1, 1979-April 30, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Rauh, R.D.; Rose, T.L.; Scoville, A.N.

    1980-04-01

    The work reported was directed towards evaluation of new amorphous compounds for application in solar cells. The ternary A/sup II/B/sup IV/C/sub 2//sup V/ chalcopyrite systems were selected because of their inexpensive constituent elements and tetrahedral geometry. Polycrystalline samples of the ternary arsenides with Cd and Zn as the group II element and Ge, Si, Sn as the group IV element were synthesized. Thin films were deposited by vacuum evaporation of the bulk ternary arsenides. The stoichiometries of the films were irreproducible and were usually deficient in the lower vapor pressure group IV element. Films made by evaporating polycrystalline ZnAs/sub 2/, which also has a tetrahedral bonding structure, had stoichiometries generally in the range from Zn/sub 3/As/sub 2/ to ZnAs/sub 2/. The former compound is formed by the decomposition of ZnAs/sub 2/ to Zn/sub 3/As/sub 2/ and As/sub 4/. The intermediate stoichiometries are thought to be mixtures of the decomposition products. Preliminary results from annealing of the films indicate that heat treatment produces the stoichiometries expected for one of the two forms of zinc arsenide. The as-deposited films are amorphous when the substrate temperature is kept below 100/sup 0/C. The a-ZnAs/sub x/ films were characterized. EDAX and Auger analysis showed that films were homogeneous in the plane of the substrate, but that some variation occurred in the depth profile of the films. This change in composition is consistent with the sample decomposition which occurs during the evaporation. The as-prepared films were p-type with room temperature resistivities on the order of 10/sup 2/-10/sup 4/..cap omega..-cm. Optical absorption measurements gave optical band gap values of 1.2 eV for a-Zn/sub 3/As/sub 2/ and 1.5 eV for a-ZnAs/sub 2/. The ZnAs/sub x/ films were photoconductive.

  14. Environmental testing of Block II solar cell modules. Low-Cost Solar Array Project

    Energy Technology Data Exchange (ETDEWEB)

    Griffith, J.S.

    1979-01-01

    The results of environmental tests of Block II solar modules are described. Block II was the second large scale procurement of silicon solar cell modules made by the JPL Low-Cost Solar Array Project with deliveries in 1977 and early 1978. The results of testing showed that the Block II modules were greatly improved over Block I modules. In several cases it was shown that design improvements were needed to reduce environmental test degradation. These improvements were incorporated during this production run.

  15. Scanning Probe Microscopy of Organic Solar Cells

    Science.gov (United States)

    Reid, Obadiah G.

    Nanostructured composites of organic semiconductors are a promising class of materials for the manufacture of low-cost solar cells. Understanding how the nanoscale morphology of these materials affects their efficiency as solar energy harvesters is crucial to their eventual potential for large-scale deployment for primary power generation. In this thesis we describe the use of optoelectronic scanning-probe based microscopy methods to study this efficiency-structure relationship with nanoscale resolution. In particular, our objective is to make spatially resolved measurements of each step in the power conversion process from photons to an electric current, including charge generation, transport, and recombination processes, and correlate them with local device structure. We have achieved two aims in this work: first, to develop and apply novel electrically sensitive scanning probe microscopy experiments to study the optoelectronic materials and processes discussed above; and second, to deepen our understanding of the physics underpinning our experimental techniques. In the first case, we have applied conductive-, and photoconductive atomic force (cAFM & pcAFM) microscopy to measure both local photocurrent collection and dark charge transport properties in a variety of model and novel organic solar cell composites, including polymer/fullerene blends, and polymer-nanowire/fullerene blends, finding that local heterogeneity is the rule, and that improvements in the uniformity of specific beneficial nanostructures could lead to large increases in efficiency. We have used scanning Kelvin probe microscopy (SKPM) and time resolved-electrostatic force microscopy (trEFM) to characterize all-polymer blends, quantifying their sensitivity to photochemical degradation and the subsequent formation of local charge traps. We find that while trEFM provides a sensitive measure of local quantum efficiency, SKPM is generally unsuited to measurements of efficiency, less sensitive than tr

  16. Determination of Zinc, Cadmium and Lead Bioavailability in Contaminated Soils at the Single-Cell Level by a Combination of Whole-Cell Biosensors and Flow Cytometry

    Directory of Open Access Journals (Sweden)

    Quentin Hurdebise

    2015-04-01

    Full Text Available Zinc, lead and cadmium are metallic trace elements (MTEs that are widespread in the environment and tend to accumulate in soils because of their low mobility and non-degradability. The purpose of this work is to evaluate the applicability of biosensors as tools able to provide data about the bioavailability of such MTEs in contaminated soils. Here, we tested the genetically-engineered strain Escherichia coli pPZntAgfp as a biosensor applicable to the detection of zinc, lead and cadmium by the biosynthesis of green fluorescent protein (GFP accumulating inside the cells. Flow cytometry was used to investigate the fluorescence induced by the MTEs. A curvilinear response to zinc between 0 and 25 mg/L and another curvilinear response to cadmium between 0 and 1.5 mg/L were highlighted in liquid media, while lead did not produce exploitable results. The response relating to a Zn2+/Cd2+ ratio of 10 was further investigated. In these conditions, E. coli pPZntAgfp responded to cadmium only. Several contaminated soils with a Zn2+/Cd2+ ratio of 10 were analyzed with the biosensor, and the metallic concentrations were also measured by atomic absorption spectroscopy. Our results showed that E. coli pPZntAgfp could be used as a monitoring tool for contaminated soils being processed.

  17. Inexpensive transparent nanoelectrode for crystalline silicon solar cells

    Science.gov (United States)

    Peng, Qiang; Pei, Ke; Han, Bing; Li, Ruopeng; Zhou, Guofu; Liu, Jun-Ming; Kempa, Krzysztof; Gao, Jinwei

    2016-06-01

    We report an easily manufacturable and inexpensive transparent conductive electrode for crystalline silicon (c-Si) solar cells. It is based on a silver nanoparticle network self-forming in the valleys between the pyramids of a textured solar cell surface, transformed into a nanowire network by sintering, and subsequently "buried" under the silicon surface by a metal-assisted chemical etching. We have successfully incorporated these steps into the conventional c-Si solar cell manufacturing process, from which we have eliminated the expensive screen printing and firing steps, typically used to make the macro-electrode of conducting silver fingers. The resulting, preliminary solar cell achieved power conversion efficiency only 14 % less than the conventionally processed c-Si control cell. We expect that a cell with an optimized processing will achieve at least efficiency of the conventional commercial cell, but at significantly reduced manufacturing cost.

  18. Workshop proceedings: Photovoltaic conversion of solar energy for terrestrial applications. Volume 1: Working group and panel reports

    Science.gov (United States)

    1973-01-01

    Technological aspects of solar energy conversion by photovoltaic cells are considered. The advantage of the single crystal silicon solar cell approach is developed through comparisons with polycrystalline silicon, cadmium sulfide/copper sulfide thin film cells, and other materials and devices.

  19. Electrodeposition of ZnO-doped films as window layer for Cd-free CIGS-based solar cells

    Science.gov (United States)

    Tsin, Fabien; Vénérosy, Amélie; Hildebrandt, Thibaud; Hariskos, Dimitrios; Naghavi, Negar; Lincot, Daniel; Rousset, Jean

    2016-02-01

    The Cu(In,Ga)Se2 (CIGS) thin film solar cell technology has made a steady progress within the last decade reaching efficiency up to 22.3% on laboratory scale, thus overpassing the highest efficiency for polycrystalline silicon solar cells. High efficiency CIGS modules employ a so-called buffer layer of cadmium sulfide CdS deposited by Chemical Bath Deposition (CBD), which presence and Cd-containing waste present some environmental concerns. A second potential bottleneck for CIGS technology is its window layer made of i-ZnO/ZnO:Al, which is deposited by sputtering requiring expensive vacuum equipment. A non-vacuum deposition of transparent conductive oxide (TCO) relying on simpler equipment with lower investment costs will be more economically attractive, and could increase competitiveness of CIGS-based modules with the mainstream silicon-based technologies. In the frame of Novazolar project, we have developed a low-cost aqueous solution photo assisted electrodeposition process of the ZnO-based window layer for high efficiency CIGS-based solar cells. The window layer deposition have been first optimized on classical CdS buffer layer leading to cells with efficiencies similar to those measured with the sputtered references on the same absorber (15%). The the optimized ZnO doped layer has been adapted to cadmium free devices where the CdS is replaced by chemical bath deposited zinc oxysulfide Zn(S,O) buffer layer. The effect of different growth parameters has been studied on CBD-Zn(S,O)-plated co-evaporated Cu(In,Ga)Se2 substrates provided by the Zentrum für Sonnenenergie-und Wasserstoff-Forschung (ZSW). This optimization of the electrodeposition of ZnO:Cl on CIGS/Zn(S,O) stacks led to record efficiency of 14%, while the reference cell with a sputtered (Zn,Mg)O/ZnO:Al window layer has an efficiency of 15.2%.

  20. Bandgap Science for Organic Solar Cells

    Directory of Open Access Journals (Sweden)

    Masahiro Hiramoto

    2014-06-01

    Full Text Available The concept of bandgap science of organic semiconductor films for use in photovoltaic cells, namely, high-purification, pn-control by doping, and design of the built-in potential based on precisely-evaluated doping parameters, is summarized. The principle characteristics of organic solar cells, namely, the exciton, donor (D/acceptor (A sensitization, and p-i-n cells containing co-deposited and D/A molecular blended i-interlayers, are explained. ‘Seven-nines’ (7N purification, together with phase-separation/cystallization induced by co-evaporant 3rd molecules allowed us to fabricate 5.3% efficient cells based on 1 µm-thick fullerene:phthalocyanine (C60:H2Pc co-deposited films. pn-control techniques enabled by impurity doping for both single and co-deposited films were established. The carrier concentrations created by doping were determined by the Kelvin band mapping technique. The relatively high ionization efficiency of 10% for doped organic semiconductors can be explained by the formation of charge transfer (CT-complexes between the dopants and the organic semiconductor molecules. A series of fundamental junctions, such as Schottky junctions, pn-homojunctions, p+, n+-organic/metal ohmic junctions, and n+-organic/ p+-organic ohmic homojunctions, were fabricated in both single and co-deposited organic semiconductor films by impurity doping alone. A tandem cell showing 2.4% efficiency was fabricated in which the built-in electric field was designed by manipulating the doping.