WorldWideScience

Sample records for cadmium arsenide solar cells

  1. 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.

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

    International Nuclear Information System (INIS)

    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

  3. 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.

  4. 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.

  5. Radiative recombination and photon recycling in gallium arsenide solar cells

    Science.gov (United States)

    Lundstrom, M. S.; Melloch, M. R.; Lush, G. B.; Patkar, M. P.; Young, M.; Durbin, S. M.; Gray, J. L.; MacMillan, H. F.; Keyes, B. M.; Levi, D. H.; Ahrenkiel, R. K.

    1992-12-01

    This talk reviews experimental work to develop a detailed understanding of radiative recombination in n-GaAs. Photoluminescence decay studies of minority carrier lifetimes versus doping in n-GaAs are presented. We show that when the substrate is removed by etching, photon recycling is enhanced, and lifetimes increase by nearly a factor of 10. The doping-dependent absorption coefficient is measured, and detailed balance arguments are used to relate absorption and recombination. Modeling surfaces, verified by comparison with experiments, are used to examine the effects of recycling in conventional solar cells and to explore new design options.

  6. Thin-film cadmium telluride solar cells

    Science.gov (United States)

    Chu, T. L.

    1987-10-01

    Cadmium telluride, with a room-temperature band-gap energy of 1.5 eV, is a promising thin-film photovoltaic material. The major objective of this research has been to demonstrate thin-film CdTe heterojunction solar cells with a total area greater than 1 sq cm and photovoltaic efficiencies of 13 percent or more. Thin-film p-CdTe/CdS/SnO2:F/glass solar cells with an AM1.5 efficiency of 10.5 percent have been reported previously. This report contains results of work done on: (1) the deposition, resistivity control, and characterization of p-CdTe films by the close-spaced sublimation process; (2) the deposition of large-band-gap window materials; (3) the electrical properties of CdS/CdTe heterojunctions; (4) the formation of stable, reproducible, ohmic contacts (such as p-HgTe) to p-CdTe; and (5) the preparation and evaluation of heterojunction solar cells.

  7. Cadmium Telluride Solar Cells with PEDOT:PSS Back Contact

    Science.gov (United States)

    Mount, Michael; Duarte, Fernanda; Paudel, Naba; Yan, Yanfa; Wang, Weining

    Cadmium Telluride (CdTe) solar cell is one of the most promising thin film solar cells and its highest efficiency has reached 21%. To keep improving the efficiency of CdTe solar cells, a few issues need to be addressed, one of which is the back contact. The back contact of CdTe solar cells are mostly Cu-base, and the problem with Cu-based back contact is that Cu diffuses into the grain boundary and into the CdS/CdTe junction, causing degradation problem at high temperature and under illumination. To continue improving the efficiency of CdTe/CdS solar cells, a good ohmic back contact with high work function and long term stability is needed. In this work, we report our studies on the potential of conducting polymer being used as the back contact of CdTe/CdS solar cells. Conducting polymers are good candidates because they have high work functions and high conductivities, are easy to process, and cost less, meeting all the requirements of a good ohmic back contact for CdTe. In our studies, we used poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) with different conductivities and compared them with traditional Cu-based back contact. It was observed that the CdTe solar cell performance improves as the conductivity of the PEDOT:PSS increase, and the efficiency (9.1%) is approaching those with traditional Cu/Au back contact (12.5%). Cadmium Telluride Solar Cells with PEDOT:PSS Back Contact.

  8. Thin film cadmium telluride solar cells

    Science.gov (United States)

    Chu, T. L.; Chu, Shirley S.; Ang, S. T.; Mantravadi, M. K.

    1987-08-01

    Thin-film p-CdTe/CdS/SnO2:F/glass solar cells of the inverted configuration were prepared by the deposition of p-type CdTe films onto CdS/SnO2:F/glass substrates using CVD or close-spaced sublimation (CSS) techniques based on the procedures of Chu et al. (1983) and Nicholl (1963), respectively. The deposition rates of p-CdTe films deposited by CSS were higher than those deposited by the CVD technique (4-5 min were sufficient), and the efficiencies higher than 10 percent were obtained. However, the resistivity of films prepared by CSS was not as readily controlled as that of the CVD films. The simplest technique to reduce the resistivity of the CSS p-CdTe films was to incorporate a dopant, such as As or Sb, into the reaction mixture during the preparation of the source material. The films with resistivities in the range of 500-1000 ohm cm were deposited in this manner.

  9. Light-trapping and recycling for extraordinary power conversion in ultra-thin gallium-arsenide solar cells.

    Science.gov (United States)

    Eyderman, Sergey; John, Sajeev

    2016-01-01

    We demonstrate nearly 30% power conversion efficiency in ultra-thin (~200 nm) gallium arsenide photonic crystal solar cells by numerical solution of the coupled electromagnetic Maxwell and semiconductor drift-diffusion equations. Our architecture enables wave-interference-induced solar light trapping in the wavelength range from 300-865 nm, leading to absorption of almost 90% of incoming sunlight. Our optimized design for 200 nm equivalent bulk thickness of GaAs, is a square-lattice, slanted conical-pore photonic crystal (lattice constant 550 nm, pore diameter 600 nm, and pore depth 290 nm), passivated with AlGaAs, deposited on a silver back-reflector, with ITO upper contact and encapsulated with SiO2. Our model includes both radiative and non-radiative recombination of photo-generated charge carriers. When all light from radiative recombination is assumed to escape the structure, a maximum achievable photocurrent density (MAPD) of 27.6 mA/cm(2) is obtained from normally incident AM 1.5 sunlight. For a surface non-radiative recombination velocity of 10(3) cm/s, this corresponds to a solar power conversion efficiency of 28.3%. When all light from radiative recombination is trapped and reabsorbed (complete photon recycling) the power conversion efficiency increases to 29%. If the surface recombination velocity is reduced to 10 cm/sec, photon recycling is much more effective and the power conversion efficiency reaches 30.6%. PMID:27334045

  10. Light-trapping and recycling for extraordinary power conversion in ultra-thin gallium-arsenide solar cells

    Science.gov (United States)

    Eyderman, Sergey; John, Sajeev

    2016-01-01

    We demonstrate nearly 30% power conversion efficiency in ultra-thin (~200 nm) gallium arsenide photonic crystal solar cells by numerical solution of the coupled electromagnetic Maxwell and semiconductor drift-diffusion equations. Our architecture enables wave-interference-induced solar light trapping in the wavelength range from 300–865 nm, leading to absorption of almost 90% of incoming sunlight. Our optimized design for 200 nm equivalent bulk thickness of GaAs, is a square-lattice, slanted conical-pore photonic crystal (lattice constant 550 nm, pore diameter 600 nm, and pore depth 290 nm), passivated with AlGaAs, deposited on a silver back-reflector, with ITO upper contact and encapsulated with SiO2. Our model includes both radiative and non-radiative recombination of photo-generated charge carriers. When all light from radiative recombination is assumed to escape the structure, a maximum achievable photocurrent density (MAPD) of 27.6 mA/cm2 is obtained from normally incident AM 1.5 sunlight. For a surface non-radiative recombination velocity of 103 cm/s, this corresponds to a solar power conversion efficiency of 28.3%. When all light from radiative recombination is trapped and reabsorbed (complete photon recycling) the power conversion efficiency increases to 29%. If the surface recombination velocity is reduced to 10 cm/sec, photon recycling is much more effective and the power conversion efficiency reaches 30.6%. PMID:27334045

  11. Thin films and solar cells of cadmium telluride and cadmium zinc telluride

    Energy Technology Data Exchange (ETDEWEB)

    Ferekides, C.S.

    1991-01-01

    The objectives of this dissertation are to investigate (1) the metalorganic chemical vapor deposition (MOCVD) and properties of cadmium telluride (CdTe) and cadmium zinc telluride (Cd(1-x)Zn(z)Te) films and junctions, and their potential application to solar cells, and (2) the fabrication and characterization of CdTe solar cells by the close spaced sublimation (CSS) technique. CdTe and Cd(1-x)Zn(x)Te films have been deposited by MOCVD on a variety of substrates at 300-400 C.The effect of the deposition parameters and post deposition heat treatments on the electrical, optical, and structural properties have been investigated. Heterojunctions of the configuration CdTe/transparent conducting semiconductor (TCS) and Cd(1-x)Zn(x)Te/TCS have been prepared and characterized. CdTe(MOCVD)/CdS and Cd(1-x)Zn(x)Te(E sub g = 1.65eV)/Cd(1-x)Zn(x)S solar cells with efficiencies of 9.9 percent and 2.4 percent, respectively have been fabricated. The as-deposited CdTe(MOCVD)/CdS junctions exhibited high dark current densities due to deflects at the interface associated with small grain size. No effective post-deposition heat treatment has been developed. CdTe/CdS solar cells have also been fabricated by the close spaced sublimation (CSS). Significant improvements in material and processing have been made, and in collaboration with fellow researchers an AM1.5 conversion efficiency of 13.4 percent has been demonstrated, the highest efficiency ever measured for such devices. The highest conversion efficiency for the CdTe(CSS)/CdS solar cell was achieved by reaching high open-circuit voltages and fill factors, while the short-circuit current densities were moderate. These results indicate that further improvements to increase the short-circuit current densities can result in conversion efficiencies over 15 percent.

  12. Method of making a thin film cadmium telluride solar cell

    International Nuclear Information System (INIS)

    A method for making a photovoltaic cell is described comprising the steps of: (a) depositing a transparent or semi-transparent conductive window layer onto a substrate; (b) depositing a layer of cadmium telluride including phosphorus onto the window layer; (c) depositing a layer of lead telluride onto the layer of cadmium telluride; and (d) depositing a metallic electrode onto the lead telluride layer

  13. Stable, high efficiency thin film solar cells produced by electrodeposition of cadmium telluride

    Energy Technology Data Exchange (ETDEWEB)

    Turner, A.K.; Woodcock, J.M.; Ozsan, M.E.; Summers, J.G.; Barker, J.; Binns, S.; Buchanan, K.; Chai, C.; Dennison, S.; Hart, R.; Johnson, D.; Marshall, R.; Oktik, S.; Patterson, M.; Perks, R.; Roberts, S.; Sadeghi, M.; Sherborne, J.; Szubert, J.; Webster, S. (BP Solar, Solar House, Leatherhead (United Kingdom))

    1991-12-01

    The highest known efficiency of 9.5% for a 300x300 mm series interconnected cadmium telluride solar cell is reported. In addition, efficiencies of up to 13% have been measured for small cells based on electrodeposited CdTe. The stability of modules in outdoor tests is discussed and an outline is given of the device fabrication procedure. (orig.).

  14. High efficiency indium oxide/cadmium telluride solar cells

    Science.gov (United States)

    Nakazawa, T.; Takamizawa, K.; Ito, K.

    1987-02-01

    Solar cells have been fabricated by reactive deposition of thin-film n-In2O3 onto single-crystal p-CdTe. The cell has a total area solar power conversion efficiency of 13.4 percent which corresponds to an active area efficiency of 14.4 percent at air mass 1.5 without antireflection coatings. The cell consists of a buried homojunction structure with low dark saturation current density.

  15. Improved performance of silicon nanowire/cadmium telluride quantum dots/organic hybrid solar cells

    International Nuclear Information System (INIS)

    Highlights: • We introduce an intermediate cadmium telluride quantum dots (CdTe QDs) layer between the organic with silicon nanowires of hybrid solar cells as a down-shifting layer. • The hybrid solar cell got the maximum short circuit current density of 33.5 mA/cm2, getting an increase of 15.1% comparing to solar cell without CdTe QDs. • The PCE of the hybrid solar cells with CdTe QDs layer increases 28.8%. - Abstract: We fabricated silicon nanowire/cadmium telluride quantum dots (CdTe QDs)/organic hybrid solar cells and investigated their structure and electrical properties. Transmission electron microscope revealed that CdTe QDs were uniformly distributed on the surface of the silicon nanowires, which made PEDOT:PSS easily filled the space between SiNWs. The current density–voltage (J–V) characteristics of hybrid solar cells were investigated both in dark and under illumination. The result shows that the performance of the hybrid solar cells with CdTe QDs layer has an obvious improvement. The optimal short-circuit current density (Jsc) of solar cells with CdTe QDs layer can reach 33.5 mA/cm2. Compared with the solar cells without CdTe QDs, Jsc has an increase of 15.1%. Power conversion efficiency of solar cells also increases by 28.8%. The enhanced performance of the hybrid solar cells with CdTe QDs layers are ascribed to down-shifting effect of CdTe QDs and the modification of the silicon nanowires surface with CdTe QDs. The result of our experiments suggests that hybrid solar cells with CdTe QDs modified are promising candidates for solar cell application

  16. Polycrystalline cadmium telluride 3n-i-p solar cell

    Science.gov (United States)

    Meyers, P. V.

    1989-06-01

    The CdS/CdTe/ZnTe n-i-p solar cell and its ternary relatives have the potential to meet Department of Energy cost, efficiency, and stability goals. This report describes results of a continuing program to achieve these goals. A record-breaking efficiency of 11 percent has been demonstrated and verified at the Solar Energy Research Institute (SERI). Stability testing for 3000 hours indicates that the n-i-p structure is stable. Improving the short-circuit current by substituting Cd/sub x/Zn/sub 1-x/S for CdS has been successful and has produced 8 plus percent efficient cells with 2.6 eV windows using improved pyrolysis equipment. Transparent n-i-p devices have been produced with a SERI-verified efficiency of 9.4 percent . Collaborations with researchers at the Georgia Institute of Technology, the Institute of Energy Conversion, and Jet Propulsion Laboratory have resulted in jointly produced n-i-p cells. Cells produced by molecular beam epitaxy and metal organic chemical vapor deposition had efficiencies greater than 9 percent; cells produced by thermal vacuum evaporation had efficiencies greater than 7 percent.

  17. 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.

  18. About some methods of obtaining of cheap gallium arsenide photo converters and solar batteries on their base

    International Nuclear Information System (INIS)

    The article presents the talk on some methods of obtaining cheap gallium arsenide photo-converters and solar batteries on their basis given at the International Workshop on applied solar energy held in Tashkent (Uzbekistan) in June 1997. The technology elaborated permits to obtain solar cells with efficiency of photo-conversion up to 20%. The electrical and photoelectrical properties of obtained cells were investigated. The elaborated solar cells are used in portable devices working in field conditions. (A.A.D.)

  19. Cadmium sulfide thin films deposited by close spaced sublimation and cadmium sulfide/cadmium telluride solar cells

    Science.gov (United States)

    Marinskiy, Dmitriy Nikolaevich

    1998-12-01

    One of the applications of CdS films is as a window layer in CdTe and Cu(In,Ga)Sesb2 solar cells. The study of the optical and structural properties of CdS films deposited by close spaced sublimation as well as their influence on CdS/CdTe solar cell performance is part of the CdTe solar cell program at the University of South Florida. CdS films have been deposited by the close-spaced sublimation technique. The influence of the main process parameters, the substrate and source temperatures, and the ambient in the deposition chamber has been investigated. As-deposited films have been subjected to heat treatments in Hsb2 ambient, in CdClsb2 atmosphere, and in atmosphere with small amounts of oxygen. A special annealing chamber was built to carry out the annealing experiments in the presence of CdClsb2 vapor and oxygen. Several CSS chambers were assembled to study the influence of various process parameters simultaneously and validate the results. Results of scanning electron microscopy and photoluminescence measurements have been used as the primary characterization techniques. X-ray diffraction, electron microprobe analysis, and transmission measurements have also been carried out. It was found that as deposited CdS films have a hexagonal structure independent of the process parameters used. The presence of a CdO phase was detected in the samples grown with the highest oxygen concentration in the ambient. The resistivity of CdS films is controlled by intergrain barriers. Photoluminescence measurements showed the presence of oxygen-acceptor transition and a wide variation in the intensity of deep emission bands. The variation in the intensities was correlated with the variation in the deposition and annealing conditions. However, no correlation was found between the PL intensities of defect bands and cell performance. CdS/CdTe junctions have been fabricated using standard deposition and postgrowth techniques developed in the USF solar cells laboratory. All cells have

  20. 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.

  1. Varying cadmium telluride growth temperature during deposition to increase solar cell reliability

    Energy Technology Data Exchange (ETDEWEB)

    Albin, David S.; Johnson, James Neil; Zhao, Yu; Korevaar, Bastiaan Arie

    2016-04-26

    A method for forming thin films or layers of cadmium telluride (CdTe) for use in photovoltaic modules or solar cells. The method includes varying the substrate temperature during the growth of the CdTe layer by preheating a substrate (e.g., a substrate with a cadmium sulfide (CdS) heterojunction or layer) suspended over a CdTe source to remove moisture to a relatively low preheat temperature. Then, the method includes directly heating only the CdTe source, which in turn indirectly heats the substrate upon which the CdTe is deposited. The method improves the resulting CdTe solar cell reliability. The resulting microstructure exhibits a distinct grain size distribution such that the initial region is composed of smaller grains than the bulk region portion of the deposited CdTe. Resulting devices exhibit a behavior suggesting a more n-like CdTe material near the CdS heterojunction than devices grown with substrate temperatures held constant during CdTe deposition.

  2. Thin film cadmium telluride solar cells by two chemical vapor deposition techniques

    Energy Technology Data Exchange (ETDEWEB)

    Chu, T.L.

    1988-01-15

    Cadmium telluride (CdTe) has long been recognized as a promising thin film photovoltaic material. In this work, polycrystalline p-CdTe films have been deposited by two chemical vapor deposition techniques, namely the combination of vapors of elements (CVE) and close-spaced sublimation (CSS). The CVE technique is more flexible in controlling the composition of deposited films while the CSS technique can provide very high deposition rates. The resistivity of p-CdTe films deposited by the CVE and CSS techniques can be controlled by intrinsic (cadmium vacancies) or extrinsic (arsenic or antimony) doping, and the lowest resistivity obtainable is about 200 ..cap omega.. cm. Both front-wall (CdTe/TCS/glass) and back-wall (TCS/CdTe/substrate) cells have been prepared. The back-wall cells are less efficient because of the high and irreproducible p-CdTe-substrate interface resistance. The CSS technique is superior to the CVE technique because of its simplicity and high deposition rates; however, the cleaning of the substrate in situ is more difficult. The interface cleanliness is an important factor determining the electrical and photovoltaic characteristics of the heterojunction. Heterojunction CdS/CdTe solar cells of area 1 cm/sup 2/ with conversion efficiencies higher than 10% have been prepared and junction properties characterized.

  3. Ultrafast Relaxation Dynamics of Photo-excited Dirac Fermion in Three Dimensional Dirac Semimetal Cadmium Arsenide

    CERN Document Server

    Lu, Wei; Liu, Xuefeng; Lu, Hong; Li, Caizhen; Lai, Jiawei; Zhao, Chuan; Tian, Ye; Liao, Zhimin; Jia, Shuang; Sun, Dong

    2016-01-01

    Three dimensional (3D) Dirac semimetal exhibiting ultrahigh mobility has recently attracted enormous research interests as 3D analogues of graphene. From the prospects of future application toward electronic/optoelectronic devices with extreme performance, it is crucial to understand the relaxation dynamics of photo-excited carriers and their coupling with lattice. In this work, we report ultrafast transient reflection measurements of photo-excited carrier dynamics in cadmium arsenide (Cd3As2), which is among the most stable Dirac semimetals that have been confirmed experimentally. With low energy probe photon of 0.3 eV, photo-excited Dirac Fermions dynamics closing to Dirac point are probed. Through transient reflection measurements on bulk and nanoplate samples that have different doping intensities, and systematic probe wavelength, pump power and lattice temperature dependent measurements, the dynamical evolution of carrier distributions can be retrieved qualitatively using a two-temperature model. The pho...

  4. Thin film cadmium telluride, zinc telluride, and mercury zinc telluride solar cells

    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.

  5. Effects of annealing conditions of electrodes on the photovoltaic properties of sintered cadmium sulfide/cadmium telluride solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, C.S.; Im, H.B. (Korea Advanced Inst. of Science, Seoul (Republic of Korea). Dept. of Materials Science)

    1990-01-01

    Polycrystalline n-CdS/p-CdTe solar cells with a commercial carbon paint on the p-CdTe layer and an In- Ag paint on the n-CdS layer were fabricated by a coating and sintering method. Electrical properties of the conducting paints and solar cell parameters of the heterojunction solar cells were investigated as a function of electrode annealing conditions. The sintered CdS/CdTe solar cells whose electrode contacts were annealed at 350{degrees}C for 10 min in nitrogen showed maximum values of short-circuit current density, fill factor, and solar efficiency. Commercial carbon and silver paints can be used as electrodes to fabricate sintered CdS/CdTe solar cells with efficiency over 10%.

  6. Synthesis and application in solar cell of poly(3-octylthiophene)/cadmium sulfide nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Han, Zhiyue [Institute of Modern Catalysis, Beijing University of Chemical Technology, State Key Laboratory of Chemical Resource Engineering, Beijing 100029 (China); Zhang, Jingchang; Cao, Weiliang [Institute of Modern Catalysis, Beijing University of Chemical Technology, State Key Laboratory of Chemical Resource Engineering, Beijing 100029 (China); Hainan Institute of Science and Technology, Haikou 571126 (China); Yang, Xiuying [Hainan Institute of Science and Technology, Haikou 571126 (China)

    2011-02-15

    A conducting polymer composite, poly(3-octylthiophene)/cadmium sulfide (POT/CdS) was first synthesized. Transmission electron microscope (TEM) and scanning electron microscope (SEM) depict the morphology of the samples, defining that CdS was successfully coated by poly(3-octylthiophene) molecules. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy (IR) show that there is a chemical interaction in the composite. The energy gap of the POT/CdS composite is lower at 0.824 eV, which also shows that the optical performance of the new material is far superior to POT or CdS separately, by ultraviolet-visible spectra (UV-vis). Solar cell was sensitized by POT/CdS. A solar-to-electric energy conversion efficiency of 0.581% was attained with the system. The results show that POT/CdS nanocomposites are promising materials with excellent performance characteristics in photoelectric applications. (author)

  7. Core-Shell Nanopillar Array Solar Cells using Cadmium Sulfide Coating on Indium Phosphide Nanopillars

    OpenAIRE

    Tu, Bor-An Clayton

    2013-01-01

    This thesis presents a new strategy to fabricate nanostructured indium phosphide and cadmium sulfide photovoltaics. The cells are formed by chemical bath deposition (electroless deposition) of cadmium sulfide onto indium phosphide nanopillar arrays grown by selective-area metalorganic chemical vapor deposition. Characterizations through electrical and optical measurements show that the devices consisting of p-InP core and CdS shell have a conversion efficiency, open circuit voltage, short cir...

  8. Thin-film cadmium telluride solar cells: Final subcontract report, 1 May 1985--31 May 1988

    Energy Technology Data Exchange (ETDEWEB)

    Chu, T.L.

    1988-06-01

    This report describes results of research performed to demonstrate thin-film cadmium telluride heterojunction solar cells with a total area greater than 1 cm/sup 2/ and efficiencies of 13% or higher. Efforts were directed to (1) the deposition, resistivity control, and characterization of p-CdTe films by combining the vapor of the elements (CVE) and close-spaced sublimation (CSS) techniques; (2) the deposition and characterization of transparent conducting semiconductors; (3) the deposition of p-HgTe as a low-resistance ohmic contact to p-CdTe; (4) the electrical properties of CdS/CdTe heterojunctions; and (5) the preparation and evaluation of heterojunction solar cells. CdS/CdTe solar cells showed the best photovoltaic characteristics, and the best cell had a conversion efficiency of about 10.6%. 20 refs., 30 figs., 1 tab.

  9. The 100 kW space station. [regenerative fuel cells and nickel hydrogen and nickel cadmium batteries for solar arrays

    Science.gov (United States)

    Mckhann, G.

    1977-01-01

    Solar array power systems for the space construction base are discussed. Nickel cadmium and nickel hydrogen batteries are equally attractive relative to regenerative fuel cell systems at 5 years life. Further evaluation of energy storage system life (low orbit conditions) is required. Shuttle and solid polymer electrolyte fuel cell technology appears adequate; large units (approximately four times shuttle) are most appropriate and should be studied for a 100 KWe SCB system. A conservative NiH2 battery DOD (18.6%) was elected due to lack of test data and offers considerable improvement potential. Multiorbit load averaging and reserve capacity requirements limit nominal DOD to 30% to 50% maximum, independent of life considerations.

  10. Polycrystalline thin film cadmium telluride n-i-p solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Meyers, P.V. (Ametek, Inc., Harleysville, PA (USA))

    1990-06-01

    This paper discusses experiments and analyses of technical, economic and environmental issues relating to CdTe n-i-p solar cells and their potential to satisfy the DOE PV program goals. The basic cell structure is CdS-CdTe-ZnTe. Included is an experimental and theoretical study of the operation of these devices. Experiments related to deposition of the CdS and ZnTe layers, cascaded solar cells, and module fabrication are described. Manufacturing issues relating to costs, worker safety, and environmental security are discussed. 40 refs., 25 figs., 16 tabs.

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

    Science.gov (United States)

    Rohatgi, A.; Summers, C. J.; Erbil, A.; Sudharsanan, R.; Ringel, S.

    1990-10-01

    Polycrystalline Cd(1-x)Zn(x)Te and Cd(1-x)Mn(x)Te films with a band gap of 1.7 eV were successfully grown on glass/SnO2/CdS substrates by molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD), respectively. Polycrystalline Cd(1-x)Zn(x)Te films grown by MBE resulted in uniform composition and sharp interfaces. However, polycrystalline Cd(1-x)Mn(x)Te films grown by MOCVD showed nonuniform compositions and evidence of manganese accumulation at the Cd(1-x)Mn(x)Te/CdS interface. We found that manganese interdiffuses and replaces cadmium in the CdS film. By improving the CdTe/CdS interface and, thus, reducing the collection function effects, the efficiency of the MOCVD CdTe cell can be improved to about 13.5 percent. MBE-grown CdTe cells also produced 8 to 9 percent efficiencies. The standard CdTe process was not optimum for ternary films and resulted in a decrease in the band gap. Recent results indicate that CdCl2 + ZnCl2 chemical treatment may prevent the band-gap reduction, and that chromate etch (rather than bromine etch) may provide the solution to contact resistance in the ternary cells.

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

    Energy Technology Data Exchange (ETDEWEB)

    Rohatgi, A.; Summers, C.J.; Erbil, A.; Sudharsanan, R.; Ringel, S. (Georgia Inst. of Tech., Atlanta, GA (USA). School of Electrical Engineering)

    1990-10-01

    Polycrystalline Cd{sub 1-x}Zn{sub x}Te and Cd{sub 1-x}Mn{sub x}Te films with a band gap of 1.7 eV were successfully grown on glass/SnO{sub 2}/CdS substrates by molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD), respectively. Polycrystalline Cd{sub 1-x}Zn{sub x}Te films grown by MBE resulted in uniform composition and sharp interfaces. However, polycrystalline Cd{sub 1-x}Mn{sub x}Te films grown by MOCVD showed nonuniform compositions and evidence of manganese accumulation at the Cd{sub 1-x}Mn{sub x}Te/CdS interface. We found that manganese interdiffuses and replaces cadmium in the CdS film. By improving the CdTe/CdS interface and, thus, reducing the collection function effects, the efficiency of the MOCVD CdTe cell can be improved to about 13.5%. MBE-grown CdTe cells also produced 8%--9% efficiencies. The standard CdTe process was not optimum for ternary films and resulted in a decrease in the band gap. Recent results indicate that CdCl{sub 2} + ZnCl{sub 2} chemical treatment may prevent the band-gap reduction, and that chromate etch (rather than bromine etch) may provide the solution to contact resistance in the ternary cells.

  13. Admittance spectroscopy of copper indium diselenide/cadmium sulfide solar cells

    Science.gov (United States)

    Strifler, Walter A.

    This dissertation concentrates on admittance spectroscopy of CuInSe2/CdS heterojunction solar cells prepared by chemical spray pyrolysis (CSP) and by multiple-source evaporation (MSE). The primary goal is to examine some of the more important electrical characteristics of these heterojunctions and determine if the spray-pyrolyzed cells behave similar, albeit at a lower efficiency, to higher quality cells prepared by other techniques. The primary analytical tool used in this study is admittance spectroscopy. The theory of admittance spectroscopy is developed using the concept of equivalent circuits. The traditional temperature-swept technique for admittance spectroscopy is shown to be inadequate for measuring most heterojunction samples examined in this study because of the large parallel leakage conductance found in these devices. Instead, a frequency-swept admittance technique is developed and employed to correct for the parallel conductance effect and reveal the true nature of slow charge in the depletion layer. In addition to admittance spectroscopy, the two sets of solar cell diodes are characterized using a variety of measurement techniques including capacitance-voltage, current-voltage over spectral response, capacitance dispersion over wavelength, and solar efficiency. The different pieces of experimental data are discussed to form a self-consistent physical model of the polycrystalline solar cells. Charge transport across the diode junction is dominated by recombination processes within the CuInSe2 depletion layer for both sets of diodes although the large parallel conductance in the CSP diodes often masks this characteristic. The CSP solar cells exhibit a pronounced blue peak in the spectral response indicating that electron collection is the limiting factor in the overall short-circuit quantum efficiency. A large degree of capacitance dispersion is found in both sets of diodes. Supporting measurements indicate that the majority of this dispersion is due

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

    International Nuclear Information System (INIS)

    The performance and stability of CdS/CdTe solar cells as a function of layer thickness, back contact etch, and oxygen during the CdCl2 anneal was determined. Multiple linear regression models were used to analyze the statistical significance of various first order effects and interactions. With stress, all devices showed a reduction in open-circuit voltage (V oc) and fill factor (FF) characteristic of increased recombination. Devices using thinner CdS were vulnerable to shunt formation. Oxygen during the CdCl2 anneal minimizes this effect. A thermodynamic model involving the formation of Cu-oxide is presented to explain the latter

  15. A bifacial quantum dot-sensitized solar cell with all-cadmium sulfide photoanode

    Science.gov (United States)

    Ma, Chunqing; Tang, Qunwei; Liu, Danyang; Zhao, Zhiyuan; He, Benlin; Chen, Haiyan; Yu, Liangmin

    2015-02-01

    Pursuit of a high power conversion efficiency and reduction of electricity-generation cost has been a persistent objective for quantum dot-sensitized solar cells (QDSSCs). We present here the fabrication of a QDSSC comprising a nanoflower-structured CdS anode, a liquid electrolyte having S2-/Sn2- redox couples, and a transparent CoSe counter electrode. Nanoflower-structured CdS anodes are prepared by a successive ionic layer adsorption and reaction (SILAR) method and subsequently hydrothermal strategy free of any surfactant or template. The CdS nanoparticles synthesized by a SILAR method act as "seed crystal" for growth of CdS nanoflowers. The average electron lifetime is markedly elevated in nanoflower-structured CdS anode in comparison with CdS nanoparticle or nanoporous CdS microsphere anode. Herein, we study the effect of synthesis method on CdS morphology and solar cell's photovoltaic performance, showing a power conversion efficiency of 1.67% and 1.17% for nanoflower-structured CdS QDSSC under front and rear irradiations, respectively.

  16. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1982-03-08

    The most important accomplishments during this period were to demonstrate and to elucidate further the complex effects that occur during the aging of Cu/sub 2/S/CdS thin-film solar cells in flowing wet oxygen. There are two distinct effects. At constant illumination, the short-circuit current of cells aged at room temperature consistently decreases with time. The second effect, related to diode opposing current, is more involved and may result from several competing mechanisms. Over the short term (approx. 4 to 5 hours), the magnitude of diode opposing current decreases. After approx. 20 hours of aging, opposing current generally returns to the level achieved after hydrogen annealing which immediately preceded the aging sequence. Optical measurements of the spectral transmission of the Cu/sub 2/S layers in a cell content have been made using a silicon detector epoxied to the back of a CdS cell after the copper foil substrate was removed. There is no significant change in Cu/sub 2/S transmission behavior for wavelengths ranging from 525 to 1000 nm during wet-oxygen aging for periods of 2 to 36 hours. This suggests that the decrease in J/sub SC/ at constant illumination, for the aging experiments in a flowing wet-oxygen ambient, arises because of changes in minority-carrier transport properties of the Cu/sub 2/S. Before developing a method for using an epoxied silicon detector to measure optical behavior of the Cu/sub 2/S layer, we explored the possibility of using a junction-containing wafer of silicon as a substrate for deposited CdS films. Some monolithic structures were successfully fabricated. Comparisons were made of CdS grain structure details in the junction detector area and in an adjacent metallized area.

  18. Mercury telluride as an ohmic contact to efficient thin film cadmium telluride solar cells

    International Nuclear Information System (INIS)

    The formation of a stable, reproducible, low-resistance contact to p-CdTe thin films is a major problem in the fabrication of efficient solar cells. Two general approaches to this problem are: the formation of a region of high carrier concentration under the contact to reduce the contact resistance, and the use of contact materials with a higher work function than p-CdTe. The second approach is investigated in this work using p-HgTe as the contact material. The deposition of p-HgTe on p-CdTe was carried out by the direct combination of the elemental vapors in a gas flow system and by the close-spaced sublimation, (CSS) technique. The process parameters in the direct combination technique are more readily controlled than those in the CSS technique. The p-HgTe/p-CdTe contact resistance has been found to be very similar to the Au/p-CdTe contact resistance

  19. 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. PMID:25007593

  20. 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.

  1. Errors in short circuit measurements due to spectral mismatch between sunlight and solar simulators

    Science.gov (United States)

    Curtis, H. B.

    1976-01-01

    Errors in short circuit current measurement were calculated for a variety of spectral mismatch conditions. The differences in spectral irradiance between terrestrial sunlight and three types of solar simulator were studied, as well as the differences in spectral response between three types of reference solar cells and various test cells. The simulators considered were a short arc xenon lamp AMO sunlight simulator, an ordinary quartz halogen lamp, and an ELH-type quartz halogen lamp. Three types of solar cells studied were a silicon cell, a cadmium sulfide cell and a gallium arsenide cell.

  2. High-efficiency cadmium and zinc telluride based thin-film solar cells: Annual report, June 1, 1987--May 31, 1988

    Energy Technology Data Exchange (ETDEWEB)

    Rohatgi, A.; Summers, C.J.; Erbil, A.; Sudharsanan, R.; Ringel. S.

    1989-04-01

    This report contains results of research on high-efficiency cadmium and zinc telluride based thin-film solar cells from June 1987 to May 1988. CdTe and CdZnTe and CdTe and CdMnTe films were grown on CdS/SnO/sub 2//glass substrates by molecular beam epitaxy and metal-organic chemical vapor deposition, respectively. As-grown films were characterized by x-ray diffraction, surface photovoltage spectroscopy, and infrared, Raman, and Auger electron spectroscopy, among others, for composition, bulk uniformity, thickness, and film and interface quality. Single-crystal films were grown simultaneously to understand the growth conditions of the polycrystalline films. Cell efficiencies ranging from 6.0% to 6.7% were achieved with the Cd/sub 0.95/Mn/sub 0.05/Te film employing the glass/SnO/sub 2//CdS/CdMnTe/ZnTe/Au front-wall solar cell structure. Cells fabricated by using CdZnTe films yielded efficiencies from 3.0% to 3.6%. 12 refs., 32 figs., 7 tabs.

  3. 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.

  4. Peeled film GaAs solar cell development

    International Nuclear Information System (INIS)

    Thin film, single crystal gallium arsenide (GaAs) solar cells could exhibit a specific power approaching 700 W/Kg including coverglass. A simple process has been described whereby epitaxial GaAs layers are peeled from a reusable substrate. This process takes advantage of the extreme selectivity (>106) of the etching rate of aluminum arsenide (AlAs) over GaAs in dilute hydrofloric acid (HF). The intent of this work is to demonstrate the feasibility of using the peeled film technique to fabricate high efficiency, low mass GaAs solar cells. We have successfully produced a peeled film GaAs solar cell. The device, although fractured and missing the aluminum gallium arsenide (Alx Ga1-x As) window and antireflective (AR) coating, had a Voc of 874 mV and a fill factor of 68% under AMO illumination

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

    International Nuclear Information System (INIS)

    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 (SOx). 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

  6. 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.

  7. Effect of Nanosized Tin Oxide Layer on the Efficiency of Photovoltaic Processes in Film Solar Cells Based on Cadmium Telluride

    Directory of Open Access Journals (Sweden)

    G.S. Khrypunov

    2015-03-01

    Full Text Available The influence of the thickness of the nanosized layer on the efficiency of photoelectric processes in solar cells (SC ITO / SnO2 / CdS / CdTe / Cu / Au formed on different substrates was investigated. For device structures formed on the glass substrates, the maximum efficiency of 11.4 % is achieved when thickness of the tin oxide layer is 80 nm. For flexible solar cells formed on a polyimide film, the maximum efficiency of 10.8 % is observed when thickness of the tin oxide layer is 50 nm. This paper discusses the physical mechanisms of the observed differences in efficiency.

  8. Effect of load voltage on thin film cuprous sulfide: Cadmium sulfide solar cells thermally cycled in a simulated space environment

    Science.gov (United States)

    Smithrick, J. J.; Thomas, R. D.

    1971-01-01

    Thin-film Cu2S-CdS solar cells, loaded at various fixed values of load resistance, were thermally cycled for 1429 cycles in a simulated space environment. Cell performance was measured under controlled conditions in air before and after thermal cycling. These data were used to determine the effect of load voltage on cell performance. The performance of the cells was relatively independent of load voltage up to about 0.39 volt. This appears to be a threshold voltage, beyond which there was a significant loss in cell performance. Fortunately, this threshold voltage appears to be sufficiently higher than the maximum power voltage of 0.33 volt so that it can be avoided in most applications.

  9. Controlled cadmium telluride thin films for solar cell applications (emerging materials systems for solar cell applications). Quarterly progress report No. 3, October 9, 1979-January 8, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Vedam, K; Das, M B; Krishnaswamy, S V

    1980-02-01

    The main emphasis during the third quarter of the program was on the improvement of the quality of sputtered films, their characterization and use in the fabrication of Schottky barrier type diodes and solar cell structures. Films prepared under different conditions and on different substrates were examined by SEM showing nodular growths under certain conditions. I-V, C-V and photovoltaic characteristics were measured on numerous samples based on n- and p-type films on Ni substrates having top metallization of either evaporated Au and Al. The n-type samples showed up to 200mV V/sub oc/ and small short-circuit currents. The characteristics observed are indicative of the presence of interfacial layer and surface states. Surface state's capacitance were measured on p-type samples metallized with Au.

  10. Polycrystalline cadmium telluride n-i-p solar cell: Annual subcontract report, 1 June 1987--31 August 1988

    Energy Technology Data Exchange (ETDEWEB)

    Meyers, P.V.

    1989-06-01

    The CdS/CdTe/ZnTe n-i-p solar cell and its ternary relatives have the potential to meet Department of Energy cost, efficiency, and stability goals. This report describes results of a continuing program to achieve these goals. A record-breaking efficiency of 11% has been demonstrated and verified at the Solar Energy Research Institute (SERI). Stability testing for 3000 hours indicates that the n-i-p structure is stable. Improving the short-circuit current by substituting Cd/sub x/Zn/sub 1-x/S for CdS has been successful and has produced 8+% efficient cells with 2.6 eV windows using improved pyrolysis equipment. Transparent n-i-p devices have been produced with a SERI-verified efficiency of 9.4%. Collaborations with researchers at the Georgia Institute of Technology, the Institute of Energy Conversion, and Jet Propulsion Laboratory have resulted in jointly produced n-i-p cells. Cells produced by molecular beam epitaxy and metal organic chemical vapor deposition had efficiencies greater than 9%; cells produced by thermal vacuum evaporation had efficiencies greater than 7%. 18 refs., 35 figs., 13 tabs.

  11. 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.

  12. InP solar cell with window layer

    Science.gov (United States)

    Jain, Raj K. (Inventor); Landis, Geoffrey A. (Inventor)

    1994-01-01

    The invention features a thin light transmissive layer of the ternary semiconductor indium aluminum arsenide (InAlAs) as a front surface passivation or 'window' layer for p-on-n InP solar cells. The window layers of the invention effectively reduce front surface recombination of the object semiconductors thereby increasing the efficiency of the cells.

  13. Cadmium sulfide nanowires for the window semiconductor layer in thin film CdS-CdTe solar cells

    International Nuclear Information System (INIS)

    Thin film CdS/CdTe heterojunction device is a leading technology for the solar cells of the next generation. We report on two novel device configurations for these cells where the traditional CdS window layer is replaced by nanowires (NW) of CdS, embedded in an aluminum oxide matrix or free-standing. An estimated 26.8% improvement in power conversion efficiency over the traditional device structure is expected, primarily because of the enhanced spectral transmission of sunlight through the NW-CdS layer and a reduction in the junction area/optical area ratio. In initial experiments, nanostructured devices of the two designs were fabricated and a power conversion efficiency value of 6.5% was achieved.

  14. An interim report on the NTS-2 solar cell experiment

    Science.gov (United States)

    Statler, R. L.; Walker, D. H.

    1979-01-01

    Data obtained from the fourteen solar cell modules on the NTS-2 satellite are presented together with a record of panel temperature and sun inclination. The following flight data are discussed: (1) state of the art solar cell configurations which embody improvements in solar cell efficiency through new silicon surface and bulk technology, (2) improved coverslip materials and coverslip bonding techniques, (3) short and long term effects of ultraviolet rejection filters vs. no filters on the cells, (4) degradation on a developmental type of liquid epitaxy gallium-aluminum-arsenide solar cell, and (5) space radiation effects.

  15. Solar cells

    Science.gov (United States)

    Cuquel, A.; Roussel, M.

    The physical and electronic characteristics of solar cells are discussed in terms of space applications. The principles underlying the photovoltaic effect are reviewed, including an analytic model for predicting the performance of individual cells and arrays of cells. Attention is given to the effects of electromagnetic and ionizing radiation, micrometeors, thermal and mechanical stresses, pollution and degassing encountered in space. The responses of different types of solar cells to the various performance-degrading agents are examined, with emphasis on techniques for quality assurance in the manufacture and mounting of Si cells.

  16. Indium phosphide/cadmium sulfide thin-film solar cells. Quarterly technical progress report No. 1, June 1979-August 1979

    Energy Technology Data Exchange (ETDEWEB)

    Zanio, K.

    1979-11-01

    Cadmium sulfide and InP thin films were prepared by thermal evaporation and planar reactive deposition, respectively. Polycrystalline CdS films up to 10 ..mu..m thick showed absorption losses of less than 10% over the 0.6- to 1.0-..mu..m wavelength range. A threefold increase in lateral grain size was achieved when CdS/ITO/GLASS structures were partially recrystallized in flowing H/sub 2/S/Ar at 550/sup 0/C. InP deposited onto (100) InP semiinsulating substrate at substrate temperatures as low as 260/sup 0/C was n-type with room-temperature mobilities as high as 1500 cm/sup 2//Vsec. The CdS and InP films were integrated into an all-thin-film InP/CdS/ITO/GLASS structure.

  17. Quantum dot solar cell

    International Nuclear Information System (INIS)

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

  18. 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.

  19. Solar cells

    International Nuclear Information System (INIS)

    A method of producing solar cells is described which consists of producing a substantially monocrystalline tubular body of silicon or other suitable semiconductor material, treating this body to form an annular rectifying junction and then cutting it longitudinally to form a number of nearly flat ribbons from which the solar cells are fabricated. The P=N rectifying junction produced by the formation of silicon dioxide on the layers at the inner and outer surfaces of the body can be formed by ion-implantation or diffusion. (U.K.)

  20. Gallium Arsenide

    Science.gov (United States)

    Brozel, Mike

    The history of gallium arsenide is complicated because the technology required to produce GaAs devices has been fraught with problems associated with the material itself and with difficulties in its fabrication. Thus, for many years, GaAs was labelled as "the semiconductor of the future, and it will always be that way." Recently, however, advances in compact-disc (CD) technology, fibre-optic communications and mobile telephony have boosted investment in GaAs research and development. Consequently, there have been advances in materials and fabrication technology and, as a result, GaAs devices now enjoy stable niche markets.

  1. Solar cells

    Science.gov (United States)

    Treble, F. C.

    1980-11-01

    The history, state of the art, and future prospects of solar cells are reviewed. Solar cells are already competitive in a wide range of low-power applications, and during the 1980's they are expected to become cheaper to run than diesel or gasoline generators, the present mainstay of isolated communities. At this stage they will become attractive for water pumping, irrigation, and rural electrification, particularly in developing countries. With further cost reduction, they may be used to augment grid supplies in domestic, commercial, institutional, and industrial premises. Cost reduction to the stage where photovoltaics becomes economic for large-scale power generation in central stations depends on a technological breakthrough in the development of thin-film cells. DOE aims to reach this goal by 1990, so that by the end of the century about 20% of the estimated annual additions to their electrical generating capacity will be photovoltaic.

  2. New cadmium sulfide nanomaterial for heterogeneous organic photovoltaic cells

    Czech Academy of Sciences Publication Activity Database

    Rohovec, Jan; Toušková, J.; Toušek, J.; Schauer, F.; Kuřitka, I.

    Linköping: Linköping University Electronic Press, Linköpings universitet, 2011 - (Moshfegh, B.), s. 2815-2822. (Linköping Electronic Conference Proceedings). ISBN 978-91-7393-070-3. ISSN 1650-3740. [World renewable energy congress. Linköping (SE), 08.05.2011-13.05.2011] R&D Projects: GA ČR GA202/09/1206 Institutional research plan: CEZ:AV0Z30130516 Keywords : nanocrysaline cadmium sulfide * preparation * photovoltaic cells * photovoltaic solar cells * triethanolamine Subject RIV: DD - Geochemistry http://www.ep.liu.se/ecp/057/Complete%20Proceeding.pdf

  3. Enhancing Solar Cell Efficiency Using Photon Upconversion Materials

    Directory of Open Access Journals (Sweden)

    Yunfei Shang

    2015-10-01

    Full Text Available 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

  4. 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 ...

  5. Effects of cadmium on nickel electrodes in nickel-cadmium cells

    International Nuclear Information System (INIS)

    Nickel cadmium battery cells containing nicel electrodes that are not treated with cadmium during the manufacturing process have a history of performance variability and capacity problems in various cell test programs. In this work cadmium additions to the nickel electrode are examined to determine the effects on the fundamental electrochemical processes occurring at this electrode. The results indicate that cadmium treatments improve recharge efficiency by increasing the potential required for oxygen evolution from the nickel electrode, thus decreasing the overcharge rate at a given voltage and allowing the nickel electrode to attain a higher state of charge. The effects of cadmium treatment become particularly important for stable cell operation at temperatures above 10 C, and for capacity maintenance under conditions of long term, low rate trickle charge

  6. Gallium arsenide p-type low temperature thermometers

    International Nuclear Information System (INIS)

    The use of p-type gallium arsenide for resistance thermometry is discussed. This semiconductor can be used for creating a family of thermometers with sufficiently small magnetoresistance and high sensitivity for the 0.3 - 350 K range. Performance characteristics of gallium arsenide doped with zinc, cadmium and manganese in the 1016 - 1018 cm-3 range of concentration and magnetoresistance in fields of up to 5T are examined. (author)

  7. Generation System of Concentrator Photovoltaic Based on Gallium Arsenide Cells%基于砷化镓电池的聚光光伏发电系统

    Institute of Scientific and Technical Information of China (English)

    宁铎; 王辉辉; 黄建兵; 李明勇

    2011-01-01

    Solar photovoltaic power generation system for the problem of low utilization, a generation system of concentrator photovoltaic (CPV) based on gallium arsenide (GaAs) cells can be designed. The system consists of concentrating power modules, solar tracking module, inverter module. Fresnel lens concentrator power generation module 400 times by concentrating light in lcm2 GaAs after the battery,the realization of power function; sun-tracking modules and optical sensors from the head to ensure that the basic vertical sunlight through the Fresnel lens; GaAs inverter module converts DC battery AC issued. After testing, the system reached 20. 2% conversion efficiency of solar, inverter part of the realization of the exchange function of the DC variable.%针对光伏发电系统中太阳能利用率低的问题,设计了一种基于砷化镓(GaAs)电池的聚光光伏(CPV)发电系统;该系统由聚光发电模块、太阳跟踪模块和逆变模块组成;聚光发电模块采用菲涅尔透镜400倍聚光以后照射在1Cmz的砷化镓电池上,实现发电功能;太阳跟踪模块由云台和光电传感器组成,保证太阳光基本垂直通过菲涅尔透镜,逆变模块将砷化镓电池发出的直流电转换成交流电;经过测试.该系统太阳能转换效率达到20.2%,逆变部分实现了直流变交流功能.

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

    International Nuclear Information System (INIS)

    Cd(1−x)ZnxS (CdS:Zn) thin films were grown on an indium tin oxide-coated glass substrate and Cu(In,Ga)Se2 (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)Se2 (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

  9. Cadmium uptake by rat red blood cells

    International Nuclear Information System (INIS)

    Rat red blood cells were employed to study the uptake of cadmium (109Cd). Suspensions of red blood cells were exposed to Cd concentrations (both bound and free) observed following in vivo Cd administration. Cd uptake was biphasic with an initial rapid phase (0C was one-fourth of that at 370C. The metabolic inhibitors: sodium fluoride (1mM), potassium cyanide (1mM) and carbonyl cyanide-m-chlorophenyl hydrazone (2μM) and the Na+-K+-ATPase inhibitor, ouabain (1mM) did not reduce Cd (50μM) uptake into red blood cells. This suggests that the uptake of Cd into red blood cells was not an active process. Incubation of Cd (10μM) with an equimolar concentration of Zn did not alter uptake of Cd into red blood cells, but at 5 and 10 times higher concentrations of Zn, Cd uptake was enhanced 5-fold. Mercury at one-tenth and equimolar concentrations of Cd increased Cd uptake by red blood cells 2-fold. N-Ethylmaleimide (0.5-5mM), which irreversibly inactivates membrane sulfhydryl groups, decreased Cd uptake. The data indicate that Cd uptake into rat red blood cells occurs by passive transport and that alterations of sulfhydryls of red blood cell membrane may modulate the process. (author)

  10. Introduction to solar cell production

    International Nuclear Information System (INIS)

    This book introduces solar cell production. It is made up eight chapters, which are summary of solar cell with structure and prospect of the business, special variable of solar cell on light of the sun and factor causing variable of solar cell, production of solar cell with surface texturing, diffusion, metal printing dry and firing and edge isolation, process of solar cell on silicone wafer for solar cell, forming of electrodes, introduction of thin film solar cell on operating of solar cell, process of production and high efficiency of thin film solar cell, sorting of solar cell and production with background of silicone solar cell and thin film solar cell, structure and production of thin film solar cell and compound solar cell, introduction of solar cell module and the Industrial condition and prospect of solar cell.

  11. 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....

  12. PEROVSKITE SOLAR CELLS (REVIEW ARTICLE)

    OpenAIRE

    Benli, Deniz Ahmet

    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...

  13. Solar cell concentrating system

    International Nuclear Information System (INIS)

    This study reviews fabrication techniques and testing facilities for different solar cells under concentration which have been developed and tested. It is also aimed to examine solar energy concentrators which are prospective candidates for photovoltaic concentrator systems. This may provide an impetus to the scientists working in the area of solar cell technology

  14. 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.

  15. Cadmium (II) removal mechanisms in microbial electrolysis cells.

    Science.gov (United States)

    Colantonio, Natalie; Kim, Younggy

    2016-07-01

    Cadmium is a toxic heavy metal, causing serious environmental and human health problems. Conventional methods for removing cadmium from wastewater are expensive and inefficient for low concentrations. Microbial electrolysis cells (MECs) can simultaneously treat wastewater, produce hydrogen gas, and remove heavy metals with low energy requirements. Lab-scale MECs were operated to remove cadmium under various electric conditions: applied voltages of 0.4, 0.6, 0.8, and 1.0V; and a fixed cathode potential of -1.0V vs. Ag/AgCl. Regardless of the electric condition, rapid removal of cadmium was demonstrated (50-67% in 24h); however, cadmium concentration in solution increased after the electric current dropped with depleted organic substrate under applied voltage conditions. For the fixed cathode potential, the electric current was maintained even after substrate depletion and thus cadmium concentration did not increase. These results can be explained by three different removal mechanisms: cathodic reduction; Cd(OH)2 precipitation; and CdCO3 precipitation. When the current decreased with depleted substrates, local pH at the cathode was no longer high due to slowed hydrogen evolution reaction (2H(+)+2e(-)→H2); thus, the precipitated Cd(OH)2 and CdCO3 started dissolving. To prevent their dissolution, sufficient organic substrates should be provided when MECs are used for cadmium removal. PMID:26970043

  16. 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.

  17. Laboratory Study on Integrated Solar Electrokinetic Barrier for Preventing Cadmium Contamination

    Directory of Open Access Journals (Sweden)

    Eltayeb Mohamedelhassan

    2011-08-01

    Full Text Available The aim of this laboratory study is to investigate the use of electrokinetic barrier powered by solar panel to prevent Cadmium (Cd contamination of clayey soil by hydraulic flow. Along with the solar panel, DC power supply was also used as a power source for comparison. The electric field generated by the solar panel was only during the daytime (14 h 45 min per day while the DC power supply provided the barrier with continuous electric field. The tests were carried out in five identical electrokinetic column cells. The hydraulic flow was generated by a constant gradient of 10. The results showed that electrokinetic barrier with solar power of peak electric field gradient of 2 V/cm during the daytime was equally efficient to a barrier that was powered continuously at 2 V/cm to stop the migration of Cd by the hydraulic flow. The results suggested that the generated electro-osmosis and electro-migration flux were stronger than the hydraulic flow as the Cd was found migrated up-gradient of the hydraulic flow. The volume of water collected during the test, water content distribution, pH profile, and Cd concentration after the test were consistent with electrokinetic phenomenon.

  18. Recent technological advances in thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Ullal, H.S.; Zwelbel, K.; Surek, T.

    1990-03-01

    High-efficiency, low-cost thin film solar cells are an exciting photovoltaic technology option for generating cost-effective electricity in 1995 and beyond. This paper reviews the substantial advances made by several thin film solar cell technologies, namely, amorphous silicon, copper indium diselenide, cadmium telluride, and polycrystalline silicon. Recent examples of utility demonstration projects of these emerging materials are also discussed. 8 refs., 4 figs.

  19. 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

  20. Induction of cytoprotective autophagy in PC-12 cells by cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qiwen [College of Veterinary Medicine, Yangzhou University, Yangzhou 225009 (China); Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009 (China); Bijie Pilot Area Research Institute of Bijie University, Bijie 551700 (China); Zhu, Jiaqiao; Zhang, Kangbao; Jiang, Chenyang; Wang, Yi; Yuan, Yan; Bian, Jianchun; Liu, Xuezhong; Gu, Jianhong [College of Veterinary Medicine, Yangzhou University, Yangzhou 225009 (China); Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009 (China); Liu, Zongping, E-mail: liuzongping@yzu.edu.cn [College of Veterinary Medicine, Yangzhou University, Yangzhou 225009 (China); Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009 (China)

    2013-08-16

    Highlights: •Cadmium can promote early upregulation of autophagy in PC-12 cells. •Autophagy precedes apoptosis in cadmium-treated PC-12 cells. •Cadmium-induced autophagy is cytoprotective in PC-12 cells. •Class III PI3K/beclin-1/Bcl-2 signaling pathway plays a positive role in cadmium-triggered autophagy. -- Abstract: Laboratory data have demonstrated that cadmium (Cd) may induce neuronal apoptosis. However, little is known about the role of autophagy in neurons. In this study, cell viability decreased in a dose- and time-dependent manner after treatment with Cd in PC-12 cells. As cells were exposed to Cd, the levels of LC3-II proteins became elevated, specific punctate distribution of endogenous LC3-II increased, and numerous autophagosomes appeared, which suggest that Cd induced a high level of autophagy. In the late stages of autophagy, an increase in the apoptosis ratio was observed. Likewise, pre-treatment with chloroquine (an autophagic inhibitor) and rapamycin (an autophagic inducer) resulted in an increased and decreased percentage of apoptosis in contrast to other Cd-treated groups, respectively. The results indicate that autophagy delayed apoptosis in Cd-treated PC-12 cells. Furthermore, co-treatment of cells with chloroquine reduced autophagy and cell activity. However, rapamycin had an opposite effect on autophagy and cell activity. Moreover, class III PI3 K/beclin-1/Bcl-2 signaling pathways served a function in Cd-induced autophagy. The findings suggest that Cd can induce cytoprotective autophagy by activating class III PI3 K/beclin-1/Bcl-2 signaling pathways. In sum, this study strongly suggests that autophagy may serve a positive function in the reduction of Cd-induced cytotoxicity.

  1. Induction of cytoprotective autophagy in PC-12 cells by cadmium

    International Nuclear Information System (INIS)

    Highlights: •Cadmium can promote early upregulation of autophagy in PC-12 cells. •Autophagy precedes apoptosis in cadmium-treated PC-12 cells. •Cadmium-induced autophagy is cytoprotective in PC-12 cells. •Class III PI3K/beclin-1/Bcl-2 signaling pathway plays a positive role in cadmium-triggered autophagy. -- Abstract: Laboratory data have demonstrated that cadmium (Cd) may induce neuronal apoptosis. However, little is known about the role of autophagy in neurons. In this study, cell viability decreased in a dose- and time-dependent manner after treatment with Cd in PC-12 cells. As cells were exposed to Cd, the levels of LC3-II proteins became elevated, specific punctate distribution of endogenous LC3-II increased, and numerous autophagosomes appeared, which suggest that Cd induced a high level of autophagy. In the late stages of autophagy, an increase in the apoptosis ratio was observed. Likewise, pre-treatment with chloroquine (an autophagic inhibitor) and rapamycin (an autophagic inducer) resulted in an increased and decreased percentage of apoptosis in contrast to other Cd-treated groups, respectively. The results indicate that autophagy delayed apoptosis in Cd-treated PC-12 cells. Furthermore, co-treatment of cells with chloroquine reduced autophagy and cell activity. However, rapamycin had an opposite effect on autophagy and cell activity. Moreover, class III PI3 K/beclin-1/Bcl-2 signaling pathways served a function in Cd-induced autophagy. The findings suggest that Cd can induce cytoprotective autophagy by activating class III PI3 K/beclin-1/Bcl-2 signaling pathways. In sum, this study strongly suggests that autophagy may serve a positive function in the reduction of Cd-induced cytotoxicity

  2. 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

  3. 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.

  4. Effect of InAlAs window layer on efficiency of indium phosphide solar cells

    Science.gov (United States)

    Jain, Raj K.; Landis, Geoffrey A.

    1992-01-01

    Indium phosphide (InP) solar cell efficiencies are limited by surface recombination. The effect of a wide bandgap, lattice-matched indium aluminum arsenide (In(0.52)Al(0.48)As) window layer on the performance of InP solar cells was investigated by using the numerical code PC-1D. The p(+)n InP solar cell performance improved significantly with the use of the window layer. No improvement was seen for the n(+)p InP cells. The cell results were explained by the band diagram of the heterostructure and the conduction band energy discontinuity. The calculated current voltage and internal quantum efficiency results clearly demonstrated that In(0.52)Al(0.48)As is a very promising candidate for a window layer material for p(+)n InP solar cells.

  5. Effect of InAlAs window layer on the efficiency of indium phosphide solar cells

    Science.gov (United States)

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

    1991-01-01

    Indium phosphide (InP) solar cell efficiencies are limited by surface recombination. The effect of a wide-bandgap lattice-matched indium aluminum arsenide (In0.52Al0.48As) window layer on the performance of InP solar cells was investigated using a numerical code PC-1D. The p(+)n InP solar cell performance improves significantly with the use of a window layer. No improvement is seen for n(+)p InP cells. Cell results are explained by the band diagram of the heterostructure and the conduction-band energy discontinuity. The calculated I-V and internal quantum efficiency results clearly demonstrate that In0.52Al0.48As is a promising candidate as a window layer material for p(+)n InP solar cells.

  6. Chronic cadmium exposure in vitro induces cancer cell characteristics in human lung cells

    Energy Technology Data Exchange (ETDEWEB)

    Person, Rachel J.; Tokar, Erik J.; Xu, Yuanyuan; Orihuela, Ruben; Ngalame, Ntube N. Olive; Waalkes, Michael P., E-mail: waalkes@niehs.nih.gov

    2013-12-01

    Cadmium is a known human lung carcinogen. Here, we attempt to develop an in vitro model of cadmium-induced human lung carcinogenesis by chronically exposing the peripheral lung epithelia cell line, HPL-1D, to a low level of cadmium. Cells were chronically exposed to 5 μM cadmium, a noncytotoxic level, and monitored for acquired cancer characteristics. By 20 weeks of continuous cadmium exposure, these chronic cadmium treated lung (CCT-LC) cells showed marked increases in secreted MMP-2 activity (3.5-fold), invasion (3.4-fold), and colony formation in soft agar (2-fold). CCT-LC cells were hyperproliferative, grew well in serum-free media, and overexpressed cyclin D1. The CCT-LC cells also showed decreased expression of the tumor suppressor genes p16 and SLC38A3 at the protein levels. Also consistent with an acquired cancer cell phenotype, CCT-LC cells showed increased expression of the oncoproteins K-RAS and N-RAS as well as the epithelial-to-mesenchymal transition marker protein Vimentin. Metallothionein (MT) expression is increased by cadmium, and is typically overexpressed in human lung cancers. The major MT isoforms, MT-1A and MT-2A were elevated in CCT-LC cells. Oxidant adaptive response genes HO-1 and HIF-1A were also activated in CCT-LC cells. Expression of the metal transport genes ZNT-1, ZNT-5, and ZIP-8 increased in CCT-LC cells culminating in reduced cadmium accumulation, suggesting adaptation to the metal. Overall, these data suggest that exposure of human lung epithelial cells to cadmium causes acquisition of cancer cell characteristics. Furthermore, transformation occurs despite the cell's ability to adapt to chronic cadmium exposure. - Highlights: • Chronic cadmium exposure induces cancer cell characteristics in human lung cells. • This provides an in vitro model of cadmium-induced human lung cell transformation. • This occurred with general and lung specific changes typical for cancer cells. • These findings add insight to the

  7. Chronic cadmium exposure in vitro induces cancer cell characteristics in human lung cells

    International Nuclear Information System (INIS)

    Cadmium is a known human lung carcinogen. Here, we attempt to develop an in vitro model of cadmium-induced human lung carcinogenesis by chronically exposing the peripheral lung epithelia cell line, HPL-1D, to a low level of cadmium. Cells were chronically exposed to 5 μM cadmium, a noncytotoxic level, and monitored for acquired cancer characteristics. By 20 weeks of continuous cadmium exposure, these chronic cadmium treated lung (CCT-LC) cells showed marked increases in secreted MMP-2 activity (3.5-fold), invasion (3.4-fold), and colony formation in soft agar (2-fold). CCT-LC cells were hyperproliferative, grew well in serum-free media, and overexpressed cyclin D1. The CCT-LC cells also showed decreased expression of the tumor suppressor genes p16 and SLC38A3 at the protein levels. Also consistent with an acquired cancer cell phenotype, CCT-LC cells showed increased expression of the oncoproteins K-RAS and N-RAS as well as the epithelial-to-mesenchymal transition marker protein Vimentin. Metallothionein (MT) expression is increased by cadmium, and is typically overexpressed in human lung cancers. The major MT isoforms, MT-1A and MT-2A were elevated in CCT-LC cells. Oxidant adaptive response genes HO-1 and HIF-1A were also activated in CCT-LC cells. Expression of the metal transport genes ZNT-1, ZNT-5, and ZIP-8 increased in CCT-LC cells culminating in reduced cadmium accumulation, suggesting adaptation to the metal. Overall, these data suggest that exposure of human lung epithelial cells to cadmium causes acquisition of cancer cell characteristics. Furthermore, transformation occurs despite the cell's ability to adapt to chronic cadmium exposure. - Highlights: • Chronic cadmium exposure induces cancer cell characteristics in human lung cells. • This provides an in vitro model of cadmium-induced human lung cell transformation. • This occurred with general and lung specific changes typical for cancer cells. • These findings add insight to the relationship

  8. Separator Qualification for Aerospace Nickel-cadmium Cells

    Science.gov (United States)

    Milden, M. J.

    1984-01-01

    The development plans for a new separator for nickel cadmium (NiCd) cells is described. Research includes acceptance testing, operation in a charge/discharge characterization matrix, and life testing in low earth orbit (LEO) and geosynchronous (GEO) orbit under real time and accelerated conditions.

  9. 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.

  10. Nanocrystal Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Gur, Ilan

    2006-12-15

    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.

  11. Machine vision for solar cell characterization

    Science.gov (United States)

    Ordaz, Miguel A.; Lush, Gregory B.

    2000-03-01

    An in-line, non-destructive process is being developed for characterizing polycrystalline thin-film and other large area electronic devices using computer vision based imaging of the manufacturing and inspection steps during the device fabrication process. This process is being applied specifically to Cadmium Telluride/Cadmium Sulfide (CdTe/CdS) thin film, polycrystalline solar cells. Our process involves the acquisition of reflective, transmission and electroluminescence (EL) intensity images for each device. The EL intensity images have been processed by use of a modified median cut segmentation. The processed images reveal different gray level regions corresponding to different intensities of EL originating from radiative recombination events occurring within a biased solar cell. Higher efficiency devices show a more uniform intensity distribution in contrast with lower efficiency devices. The uniform intensity regions are made up of gray level intensity values found near the mean of the histogram distribution these are identified as regions of good device performance and are attributed to better material quality and processing. Low intensity regions indicate either material defects or errors in processing. This novel characterization process and analysis are providing new insights into the causes of poor performance in CdTe-based solar cells.

  12. Thin silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Hall, R.B.; Bacon, C.; DiReda, V.; Ford, D.H.; Ingram, A.E.; Cotter, J.; Hughes-Lampros, T.; Rand, J.A.; Ruffins, T.R.; Barnett, A.M. [Astro Power Inc., Solar Park, Newark, DE (United States)

    1992-12-01

    The silicon-film design achieves high performance by using a dun silicon layer and incorporating light trapping. Optimally designed thin crystalline solar cells (<50 microns thick) have performance advantages over conventional thick devices. The high-performance silicon-film design employs a metallurgical barrier between the low-cost substrate and the thin silicon layer. Light trapping properties of silicon-film on ceramic solar cells are presented and analyzed. Recent advances in process development are described here.

  13. Sliver solar cells

    Science.gov (United States)

    Franklin, Evan; Blakers, Andrew; Everett, Vernie; Weber, Klaus

    2007-12-01

    Sliver solar cells are thin, mono-crystalline silicon solar cells, fabricated using micro-machining techniques combined with standard solar cell fabrication technology. Sliver solar modules can be efficient, low cost, bifacial, transparent, flexible, shadow-tolerant, and lightweight. Sliver modules require only 5 to 10% of the pure silicon and less than 5% of the wafer starts per MW p of factory output when compared with conventional photovoltaic modules. At ANU, we have produced 20% efficient Sliver solar cells using a robust, optimised cell fabrication process described in this paper. We have devised a rapid, reliable and simple method for extracting Sliver cells from a Sliver wafer, and methods for assembling modularised Sliver cell sub-modules. The method for forming these Sliver sub-modules, along with a low-cost method for rapidly forming reliable electrical interconnections, are presented. Using the sub-module approach, we describe low-cost methods for assembling and encapsulating Sliver cells into a range of module designs.

  14. Characterization of GaAlAs-GaAs solar cell in the system with fresnel lens

    International Nuclear Information System (INIS)

    The operation of gallium arsenide concentrator solar cell in the system with Fresnel lens is investigated. It is determined that efficiency of concentrating system strongly depends on the presence of an atmospheric steams. The obtained results show that the focusing ability of optical system decreases with the increases of dispersed component of solar radiation. This lowers short-circuit current and output power of the photo converter. The measured angular dependence of I/sub sc/ and U/sub oc/ of the concentrator module was utilized to optimize the operation of the Sun tracking system. (author)

  15. Solar cells: an environmental-friendly energy source?

    International Nuclear Information System (INIS)

    The environmental effects of the production and recycling of different types of solar cells are evaluated on the basis of life-cycle cost analyses. The life cycle analyses takes account of the production and purification of silicon, the production of crystalline and amorphous silicon modules as well as the production of cadmium telluride/CIS modules. The potential environmental effects of silicon solar cells are relatively small and are mainly linked with the emission of greenhouse gases and acidified substances during the production stage. For the cadmium telluride solar cells however, several potential problems need to be clarified before these cells are produced on a large scale. In particular, potential bottlenecks are associated with the combustion of a small fraction of modules that are not recycled. In addition, the expected emission of cadmium and selenium may be ten times larger than the emissions for modern coal based power plants in a the worst case scenario. Finally, the present knowledge on the recycling processes for cadmium telluride modules is insufficient. (A.S.)

  16. Parameterization of solar cells

    Science.gov (United States)

    Appelbaum, J.; Chait, A.; Thompson, D.

    1992-10-01

    The aggregation (sorting) of the individual solar cells into an array is commonly based on a single operating point on the current-voltage (I-V) characteristic curve. An alternative approach for cell performance prediction and cell screening is provided by modeling the cell using an equivalent electrical circuit, in which the parameters involved are related to the physical phenomena in the device. These analytical models may be represented by a double exponential I-V characteristic with seven parameters, by a double exponential model with five parameters, or by a single exponential equation with four or five parameters. In this article we address issues concerning methodologies for the determination of solar cell parameters based on measured data points of the I-V characteristic, and introduce a procedure for screening of solar cells for arrays. We show that common curve fitting techniques, e.g., least squares, may produce many combinations of parameter values while maintaining a good fit between the fitted and measured I-V characteristics of the cell. Therefore, techniques relying on curve fitting criteria alone cannot be directly used for cell parameterization. We propose a consistent procedure which takes into account the entire set of parameter values for a batch of cells. This procedure is based on a definition of a mean cell representing the batch, and takes into account the relative contribution of each parameter to the overall goodness of fit. The procedure is demonstrated on a batch of 50 silicon cells for Space Station Freedom.

  17. Cadmium Impairs p53 Activity in HepG2 Cells

    OpenAIRE

    Urani, C.; Melchioretto, P.; M. Fabbri; Bowe, G.; Maserati, E.; Gribaldo, L.

    2014-01-01

    Cadmium and cadmium compounds are contaminants of the environment, food, and drinking water and are important constituents of cigarette smoke. Cd exposure has also been associated with airborne particulate CdO and with Cd-containing quantum dots in medical therapy. Adverse cadmium effects reported in the literature have stimulated during recent years an ongoing discussion to better elucidate cadmium outcomes at cell and molecular level. The present work is designed to gain an insight into the...

  18. Solar cell element

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, Akihiko; Matsumoto, Hitoshi; Uda, Hiroshi; Komatsu, Yasumitsu; Ikegami, Kiyoharu.

    1989-05-18

    In the existing CdS/CdTe-based solar cell element, nothing is formed except the component effective for generating electromotive force and the components necessary for leading, collecting and extracting the generated electricity, hence even when the element shows deterioration of its performance during its usage, it has been difficult to analyze the above situation. In addition, it has also a defect that its characteristic such as the transfer efficiency in the neighborhood of its glass substrate in connection also with its manufacturing process. In order to solve the above problematical points, this invention proposes, with regard to a CdS-based solar cell element composed by forming a thin film on its substrate, to make a blank space on the above substrate and form thereon a thin film which composes the solar cell element concerned alone or in a piling up manner. 4 figs.

  19. Reduced cadmium-induced cytotoxicity in cultured liver cells following 5-azacytidine pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    Waalkes, M.P.; Wilson, M.J.; Poirier, L.A.

    1985-11-01

    Recent work indicated that administration of the pyrimidine analog 5-azacytidine (AZA), either to cells in culture or to rats, results in an enhancement of expression of the metallothionein (MT) gene. Since MT is thought to play a central role in the detoxification of cadmium, the present study was designed to assess the effect of AZA pretreatment on cadmium cytotoxicity. Cultured rat liver cells in log phase of growth were first exposed to AZA (8 microM). Forty-eight hours later, cadmium was added. A modest increase in MT amounts over control was detected after AZA treatment alone. Cadmium alone resulted in a 10-fold increase in MT concentrations. The combination of AZA pretreatment followed by cadmium exposure caused a 23-fold increase in MT concentrations over control. Treatment with the DNA synthesis inhibitor hydroxyurea (HU) eliminated the enhancing effect of AZA pretreatment on cadmium induction of MT, indicating that cell division is required. AZA-pretreated cells were also harvested and incubated in suspension with cadmium for 0 to 90 min. AZA-pretreated cells showed marked reductions in cadmium-induced cytotoxicity as reflected by reduced intracellular potassium loss, glutamic-oxaloacetic transaminase loss, and lipid peroxidation following cadmium exposure. Results suggest that AZA pretreatment induces tolerance to cadmium cytotoxicity which appears to be due to an increased capacity to synthesize MT rather than high quantities of preexisting MT at the time of cadmium exposure.

  20. Reduced cadmium-induced cytotoxicity in cultured liver cells following 5-azacytidine pretreatment

    International Nuclear Information System (INIS)

    Recent work indicated that administration of the pyrimidine analog 5-azacytidine (AZA), either to cells in culture or to rats, results in an enhancement of expression of the metallothionein (MT) gene. Since MT is thought to play a central role in the detoxification of cadmium, the present study was designed to assess the effect of AZA pretreatment on cadmium cytotoxicity. Cultured rat liver cells in log phase of growth were first exposed to AZA (8 microM). Forty-eight hours later, cadmium was added. A modest increase in MT amounts over control was detected after AZA treatment alone. Cadmium alone resulted in a 10-fold increase in MT concentrations. The combination of AZA pretreatment followed by cadmium exposure caused a 23-fold increase in MT concentrations over control. Treatment with the DNA synthesis inhibitor hydroxyurea (HU) eliminated the enhancing effect of AZA pretreatment on cadmium induction of MT, indicating that cell division is required. AZA-pretreated cells were also harvested and incubated in suspension with cadmium for 0 to 90 min. AZA-pretreated cells showed marked reductions in cadmium-induced cytotoxicity as reflected by reduced intracellular potassium loss, glutamic-oxaloacetic transaminase loss, and lipid peroxidation following cadmium exposure. Results suggest that AZA pretreatment induces tolerance to cadmium cytotoxicity which appears to be due to an increased capacity to synthesize MT rather than high quantities of preexisting MT at the time of cadmium exposure

  1. Optoelectronics of solar cells

    CERN Document Server

    Smestad, Greg P

    2002-01-01

    With concerns about worldwide environmental security, global warming, and climate change due to emissions of carbon dioxide from the burning of fossil fuels, it is desirable to have a wide range of energy technologies in a nation's portfolio. Photovoltaics, or solar cells, are a viable option as a nonpolluting renewable energy source. This text is designed to be an overview of photovoltaic solar cells for those in the fields of optics and optical engineering, as well as those who are interested in energy policy, economics, and the requirements for efficient photo-to-electric energy conversion.

  2. 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

  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. Degradation of CIGS solar cells

    NARCIS (Netherlands)

    Theelen, M.J.

    2015-01-01

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

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

    International Nuclear Information System (INIS)

    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 μM). High doses of cadmium were required to induce a cytotoxicity: 100 μM lead to 30% mortality after 24 h 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 μM 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

  6. 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

  7. 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.

  8. Cadmium induced oxidative stress in kidney epithelia cells

    DEFF Research Database (Denmark)

    Bjerregaard, Henning F.

    2007-01-01

    Cadmium (Cd) is an important industrial and environmental pollutant. In humans exposed to Cd via oral and/or pulmonary routes, the kidney is by far the primary organ affected adversely by Cd. It have been estimated that 7% of the human population may develop renal dysfunction from Cd exposure. To...... diacetate (DCFH-DA) for measurement of intracellular ROS production in living cells. The assay is based on the fact that DCFH-DA, a non polar and non fluorescent compound can diffuse through the cell membrane and be deacetylated by cytosolic esterases to yield polar, non-fluorescent DCFH. DCFH is trapped...

  9. Cadmium-glutathione complex formation in human t-cell and b-cell lymphocytes after their incubation with organo-cadmium diacetate.

    Science.gov (United States)

    Ullah, Hashmat; Khan, Muhammad Farid; Jan, Syed Umer; Hashmat, Farwa

    2015-11-01

    Cadmium intake is associated with oxidative stress that causes depletion of intracellular as well as extra cellular reduced glutathione. There is strong evidence indicating that reactive oxygen species and reactive nitrogen species generated in the presence of cadmium could be responsible for its toxic effects in many cells and tissues. Depletion of reduced glutathione in various cells, especially in T and B-lymphocytes, causes extreme damage to the antioxidant defense system of body. The aim of this research work was to investigate the metabolic changes that occur in T and B lymphocytes after their incubation with organ cadmium diacetate by using Ellman's spectrophotometric method of thiol quantification. The results of the present study indicate that cadmium depleted T and B lymphocytes GSH to a harmful extent. It is proposed that this depletion is due to the bivalent cadmium glutathione complex formation, oxidation of reduced glutathione (GSH) to its oxidized form, or both. PMID:26639500

  10. Solar cell efficiency measurements

    International Nuclear Information System (INIS)

    Solar cells (and solar modules) have to be tested for their performance by means of sound reliable measurement procedures. The need for such measurements arises at various stages of research, of production, and of photovoltaic systems sizing and dimensioning. In fact, accurate measurements are necessary to the researcher, who studies new materials and new processes, to the manufacturer, who has to control his product and, finally, to the user, who needs sound measurements, in order to be in a position to make effective decisions about what kink of product will be needed and with what critical characteristics. In short, standard measurements that allow cells and modules to be characterized serve as a common language, allowing effective communication about products and requirements. 3 refs

  11. Metal transport in cells: cadmium uptake by rat hepatocytes and renal cortical epithelial cells.

    OpenAIRE

    Shaikh, Z A; Blazka, M E; Endo, T

    1995-01-01

    The toxic metals appear to use the transport pathways that exist for biologically essential metals. In this regard interactions between the toxic and essential metals are possible. This report summarizes recent findings on the transport of cadmium in rat hepatocytes and renal cortical epithelial cells in the presence or absence of certain essential metals. The transport of cadmium in hepatocytes does not require energy and, therefore, is not an active process. It occurs primarily (80%) by tem...

  12. Didymium compound improves nickel-cadmium cell

    Science.gov (United States)

    1965-01-01

    Nickel electrodes impregnated with an additive solution of didymium hydrate and nitric acid mixed with nickel nitrate increases ampere-hour capacity of cells and does not affect the voltage characteristics.

  13. 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...... for organic solar cell applications, opening new patterning possibilities....

  14. Transparent solar cell window module

    Energy Technology Data Exchange (ETDEWEB)

    Chau, Joseph Lik Hang; Chen, Ruei-Tang; Hwang, Gan-Lin; Tsai, Ping-Yuan [Nanopowder and Thin Film Technology Center, ITRI South, Industrial Technology Research Institute, Tainan County 709 (China); Lin, Chien-Chu [I-Lai Acrylic Corporation, Tainan City (China)

    2010-03-15

    A transparent solar cell window module based on the integration of traditional silicon solar cells and organic-inorganic nanocomposite material was designed and fabricated. The transparent solar cell window module was composed of a nanocomposite light-guide plate and traditional silicon solar cells. The preparation of the nanocomposite light-guide plate is easy without modification of the traditional casting process, the nanoparticles sol can be added directly to the polymethyl methacrylate (PMMA) monomer syrup during the process. The solar energy collected by this window can be used to power up small household electrical appliances. (author)

  15. Carbon Nanotube Solar Cells

    OpenAIRE

    Klinger, Colin; Patel, Yogeshwari; Postma, Henk W. Ch.

    2012-01-01

    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 fabr...

  16. 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

  17. High performance nickel-cadmium cells for electric vehicles

    Science.gov (United States)

    Cornu, Jean-Pierre

    A new concept of a cadmium electrode associated with a lighter nickel structure, a multi-cell module technology, allows the proposal of a very promisig alternative power source for electric vehicle (EV) batteries, the usable specific energy being 31% of the theoretical value. Every characteristic of this Ni-Cd module (i.e., specific energy and power, energy and power density, energy efficiency, life and reliability) gives the best performing EV battery, to date. Thus, with the efficient support of two major French car manufacturers and the French government, SAFT will launch, during Spring '95, the first pilot line of EV Ni-Cd module manufacturing.

  18. 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.

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

    International Nuclear Information System (INIS)

    Highlights: ► Cadmium induces secretion of IL-6 and IL-8 by two distinct pathways. ► Cadmium increases NAPDH oxidase activity leading to Erk activation and IL-8 secretion. ► Curcumin prevents cadmium-induced secretion of both IL-6 and IL-8 by airway cells. ► 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-κB 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.

  20. US Polycrystalline Thin Film Solar Cells Program

    Science.gov (United States)

    Ullal, Harin S.; Zweibel, Kenneth; Mitchell, Richard L.

    1989-11-01

    The Polycrystalline Thin Film Solar Cells Program, part of the United States National Photovoltaic Program, performs R and D on copper indium diselenide and cadmium telluride thin films. The objective of the program is to support research to develop cells and modules that meet the U.S. Department of Energy's long-term goals by achieving high efficiencies (15 to 20 percent), low-cost ($50/m(sup 2)), and long-time reliability (30 years). The importance of work in this area is due to the fact that the polycrystalline thin-film CuInSe2 and CdTe solar cells and modules have made rapid advances. They have become the leading thin films for PV in terms of efficiency and stability. The U.S. Department of Energy has increased its funding through an initiative through the Solar Energy Research Institute in CuInSe2 and CdTe with subcontracts to start in spring 1990.

  1. US polycrystalline thin film solar cells program

    Energy Technology Data Exchange (ETDEWEB)

    Ullal, H S; Zweibel, K; Mitchell, R L [Solar Energy Research Inst., Golden, CO (USA)

    1989-11-01

    The Polycrystalline Thin Film Solar Cells Program, part of the United States National Photovoltaic Program, performs R D on copper indium diselenide and cadmium telluride thin films. The objective of the Program is to support research to develop cells and modules that meet the US Department of Energy's long-term goals by achieving high efficiencies (15%-20%), low-cost ($50/m{sup 2}), and long-time reliability (30 years). The importance of work in this area is due to the fact that the polycrystalline thin-film CuInSe{sub 2} and CdTe solar cells and modules have made rapid advances. They have become the leading thin films for PV in terms of efficiency and stability. The US Department of Energy has increased its funding through an initiative through the Solar Energy Research Institute in CuInSe{sub 2} and CdTe with subcontracts to start in Spring 1990. 23 refs., 5 figs.

  2. 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.

  3. 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.

  4. Diffused quantum well solar cell

    OpenAIRE

    Lee, ASW; Li, EH; Cheng, Y

    1995-01-01

    An alternative multi-bandgap solar cell made of diffused quantum well (DFQW) as the absorber is proposed here. The modeling of the spectral response and energy conversion efficiency of the solar cell will be shown. Significant enhancement in energy conversion efficiency is demonstrated when compared to that of the single bandgap cells.

  5. 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.

  6. Thermal Management of Solar Cells

    OpenAIRE

    Saadah, Mohammed Ahmed

    2013-01-01

    The focus on solar cells as a source of photovoltaic energy is rapidly increasing nowadays. The amount of sun's energy entering earth surface in one hour is more than the world consume in one year. The photovoltaic market has been increasing by more than 20% annually since 2002. Improving solar cells aims at increasing the power conversion efficiency and reducing manufacturing costs. Crystalline silicon is the most commonly used material in making solar cells with more than 90% market use. So...

  7. Bifacial tandem solar cells

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-06-14

    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.

  8. Dye Sensitized Solar Cell, DSSC

    OpenAIRE

    Pongsatorn Amornpitoksuk; Nareelak Leesakul

    2003-01-01

    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'’-(COOH)3- terpy)(NCS)3] is the most efficient sensitizer. The total photon to c...

  9. 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...

  10. 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.

  11. Using expression profiling to understand the effects of chronic cadmium exposure on MCF-7 breast cancer cells.

    Directory of Open Access Journals (Sweden)

    Zelmina Lubovac-Pilav

    Full Text Available Cadmium is a metalloestrogen known to activate the estrogen receptor and promote breast cancer cell growth. Previous studies have implicated cadmium in the development of more malignant tumors; however the molecular mechanisms behind this cadmium-induced malignancy remain elusive. Using clonal cell lines derived from exposing breast cancer cells to cadmium for over 6 months (MCF-7-Cd4, -Cd6, -Cd7, -Cd8 and -Cd12, this study aims to identify gene expression signatures associated with chronic cadmium exposure. Our results demonstrate that prolonged cadmium exposure does not merely result in the deregulation of genes but actually leads to a distinctive expression profile. The genes deregulated in cadmium-exposed cells are involved in multiple biological processes (i.e. cell growth, apoptosis, etc. and molecular functions (i.e. cadmium/metal ion binding, transcription factor activity, etc.. Hierarchical clustering demonstrates that the five clonal cadmium cell lines share a common gene expression signature of breast cancer associated genes, clearly differentiating control cells from cadmium exposed cells. The results presented in this study offer insights into the cellular and molecular impacts of cadmium on breast cancer and emphasize the importance of studying chronic cadmium exposure as one possible mechanism of promoting breast cancer progression.

  12. 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.

  13. Hybrid solar cells using CdS thin films deposited via spray pyrolysis technique

    International Nuclear Information System (INIS)

    The paper presents the photovoltaic performance of hybrid solar cells comprising of thin films of cadmium sulphide and poly(3-hexyl)thiophene. Cadmium sulphide thin films were deposited using spray pyrolysis technique. Current-voltage characterizations were performed for cadmium sulphide/poly(3-hexyl)thiophene heterojunctions in dark and under illumination (100 mWcm−2). The best device yields a short circuit current density of 1.54 mA/cm2, an open circuit voltage of 343 mV, and a power conversion efficiency of 0.15%. - Highlights: • Hybrid solar cells were fabricated using CdS and poly(3-hexyl)thiophene. • CdS thin films were grown by spray pyrolysis technique. • The best cell performance was achieved for the 100 nm thick CdS films. • The highest short circuit current was measured as 1.54 mAcm−2 for the best cell

  14. Higher sensitivity to cadmium induced cell death of basal forebrain cholinergic neurons: A cholinesterase dependent mechanism

    International Nuclear Information System (INIS)

    Cadmium is an environmental pollutant, which is a cause of concern because it can be greatly concentrated in the organism causing severe damage to a variety of organs including the nervous system which is one of the most affected. Cadmium has been reported to produce learning and memory dysfunctions and Alzheimer like symptoms, though the mechanism is unknown. On the other hand, cholinergic system in central nervous system (CNS) is implicated on learning and memory regulation, and it has been reported that cadmium can affect cholinergic transmission and it can also induce selective toxicity on cholinergic system at peripheral level, producing cholinergic neurons loss, which may explain cadmium effects on learning and memory processes if produced on central level. The present study is aimed at researching the selective neurotoxicity induced by cadmium on cholinergic system in CNS. For this purpose we evaluated, in basal forebrain region, the cadmium toxic effects on neuronal viability and the cholinergic mechanisms related to it on NS56 cholinergic mourine septal cell line. This study proves that cadmium induces a more pronounced, but not selective, cell death on acetylcholinesterase (AChE) on cholinergic neurons. Moreover, MTT and LDH assays showed a dose dependent decrease of cell viability in NS56 cells. The ACh treatment of SN56 cells did not revert cell viability reduction induced by cadmium, but siRNA transfection against AChE partially reduced it. Our present results provide new understanding of the mechanisms contributing to the harmful effects of cadmium on the function and viability of neurons, and the possible relevance of cadmium in the pathogenesis of neurodegenerative diseases

  15. Reliability Analysis of III-V Solar Cells Grown on Recycled GaAs Substrates and an Electroplated Nickel Substrate

    Directory of Open Access Journals (Sweden)

    Ray-Hua Horng

    2013-01-01

    Full Text Available This study involved analyzing the reliability of two types of III-V solar cells: (1 III-V solar cells grown on new and recycled gallium arsenide (GaAs substrates and (2 the III-V solar cells transferred onto an electroplated nickel (Ni substrate as III-V thin-film solar cells by using a cross-shaped pattern epitaxial lift-off (CPELO process. The III-V solar cells were grown on new and recycled GaAs substrates to evaluate the reliability of the substrate. The recycled GaAs substrate was fabricated by using the CPELO process. The performance of the solar cells grown on the recycled GaAs substrate was affected by the uneven surface morphology of the recycled GaAs substrate, which caused the propagation of these dislocations into the subsequently grown active layer of the solar cell. The III-V solar cells were transferred onto an electroplated Ni substrate, which was also fabricated by using CPELO technology. The degradation of the III-V thin-film solar cell after conducting a thermal shock test could have been caused by microcracks or microvoids in the active layer or interface of the heterojunction, which resulted in the reduction of the external quantum efficiency response and the increase of recombination loss.

  16. 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…

  17. Optimization of High-Efficiency CdS/CdTe Thin Film Solar Cell Using Step Doping Grading and Thickness of the Absorption Layer

    OpenAIRE

    Masoud Sabaghi; Abbas Majdabadi; Saeid Marjani; Saeed Khosroabadi

    2015-01-01

    In this paper, the influence of stepped doping of the absorber layer on performance of Cadmium Sulfide/Cadmium Telluride (CdS/CdTe) solar cell has been investigated. At first, the electrical characteristics of conventional CdS/CdTe solar cell is validated with fabricated CdS/CdTe solar cell. To improve the maximum efficiency of CdS/CdTe solar cell, the doping and thickness of the absorption layer are optimized. By step doping concentration within the absorber layer using buffer layer back con...

  18. 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...... and characterized for comparison. Power conversion eciency of 16.5% was obtained for this batch of RIE-textured Si solar cells. The eciency of the KOH-textured reference cell was 17.8%. Quantum Efficiency measurements and carrier loss analysis show that the lower eciency of the RIE-textured cells is primarily due...

  19. Design of a thin film CdTe solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Meyers, P.V.

    1988-01-15

    Cadmium telluride was originally considered for thin film solar cells because of its optimum band gap, high optical absorption coefficient and ability to be doped. Furthermore, it is a stable compound which can be produced by a wide variety of methods from stable raw materials. As thin film photovoltaics mature, however, it is clear that several more subtle attributes have a significant impact on the viability of commercialization. We discuss the observations which have provided insight and direction to Ametek's CdTe solar cell program. Rather than try to modify the inherent material properties of CdTe, advances have been made by designing a solar cell that exploits existing properties. Specifically, the tendency to self-compensate, which makes low resistance contacting difficult, is turned into an advantage in the n-i-p configuration; the CdTe provides an intrinsic layer with good carrier collection efficiency.

  20. Back wall solar cell

    Science.gov (United States)

    Brandhorst, H. W., Jr. (Inventor)

    1978-01-01

    A solar cell is disclosed which comprises a first semiconductor material of one conductivity type with one face having the same conductivity type but more heavily doped to form a field region arranged to receive the radiant energy to be converted to electrical energy, and a layer of a second semiconductor material, preferably highly doped, of opposite conductivity type on the first semiconductor material adjacent the first semiconductor material at an interface remote from the heavily doped field region. Instead of the opposite conductivity layer, a metallic Schottky diode layer may be used, in which case no additional back contact is needed. A contact such as a gridded contact, previous to the radiant energy may be applied to the heavily doped field region of the more heavily doped, same conductivity material for its contact.

  1. Guidelines for the Procurement of Aerospace Nickel Cadmium Cells

    Science.gov (United States)

    Thierfelder, Helmut

    1997-01-01

    NASA has been using a Modular Power System containing "standard" nickel cadmium (NiCd) batteries, composed of "standard" NiCd cells. For many years the only manufacturer of the NASA "standard" NiCd cells was General Electric Co. (subsequently Gates Aerospace and now SAFT). This standard cell was successfully used in numerous missions. However, uncontrolled technical changes, and changes in industrial restructuring require a new approach. General Electric (now SAFT Aerospace Batteries) had management changes, new manufacturers entered the market (Eagle-Picher Industries, ACME Electric Corporation, Aerospace Division, Sanyo Electric Co.) and battery technology advanced. New NASA procurements for aerospace NiCd cells will have specifications unique to the spacecraft and mission requirements. This document provides the user/customer guidelines for the new approach to procuring of and specifying performance requirements for highly reliable NiCd cells and batteries. It includes details of key parameters and their importance. The appendices contain a checklist, detailed calculations, and backup information.

  2. High power nickel - cadmium cells with fiber electrodes (FNC)

    International Nuclear Information System (INIS)

    Nickel cadmium batteries differ greatly in their mechanical design and construction of the electrodes. Using available electrode constructions, batteries are designed which meet the requirements of specific applications and offer optimum performance. Pocket- and tubular cells are basically developed with the technology of the year 1895. Since then some improvements with todays technology have been made. The sintered cells use the technology of the 1930's and they are still limited to high power application. With this knowledge and the technology of today the fiber-structured nickel electrode (FNC) was developed at DAUG laboratory, a subsidiary company of Mercedes-Benz and Volkswagen. After ten years of experience in light weight prototype batteries for electric vehicles (1-2), the system was brought into production by a new company, DAUG-HOPPECKE. Characteristics of fiber electrodes: thickness and size can be easily changed; pure active materials are used; high conductor density; high elasticity of the structure; high porosity. Since 1983 NiCd-batteries with fiber-structured nickel electrodes (FNC) have been in production. Starting with the highly demanded cell-types for low, medium and high performance called L, M and H according to IEC 623 for low, medium and high performance applications, the program was recently completed with the X-type cell for very high power, as an alternative to sintered cells

  3. Labile complexes facilitate cadmium uptake by Caco-2 cells

    International Nuclear Information System (INIS)

    The Free Ion Activity Model (FIAM) predicts that metal uptake in biota is related to the free ion activity in the external solution and that metal complexes do not contribute. However, studies with plants have shown that labile metal complexes enhance metal bioavailability when the uptake is rate-limited by transport of the free ion in solution to the uptake site. Here, the role of labile complexes of Cd on metal bioavailability was assessed using Caco-2 cells, the cell model for intestinal absorption. At low Cd2+ concentration (1 nM), the CdCln2−n complexes contributed to the uptake almost to the same extent as the free ion. At large Cd2+ concentration (10 μM), the contribution of the complexes was much smaller. At constant Cd2+ concentration, Cd intake in the cells from solutions containing synthetic ligands such as EDTA increased as the dissociation rate of the cadmium complexes increased, and correlated well with the Cd diffusion flux in solution measured with the Diffusive Gradient in Thin Films technique (DGT). The Cd intake fluxes in the cells were well predicted assuming that the specific uptake is limited by diffusion of the free Cd2+ ion to the cell surface. Our results underline that speciation of Cd has a major effect on its uptake by intestinal cells, but the availability is not simply related to the free ion concentration. Labile complexes of Cd enhance metal bioavailability in these cells, likely by alleviating diffusive limitations. - Highlights: ► We examined the role of labile complexes on the uptake of Cd and Zn by Caco-2 cells. ► The availability of Cd and Zn is not simply related to the free ion activity. ► Labile complexes of Cd enhance metal bioavailability in the Caco-2 cells at low free ion activities. ► The active uptake is limited by diffusion of the free Cd2+ ion to the cell surface.

  4. Results from the high efficiency solar panel experiment flown on CRRES

    International Nuclear Information System (INIS)

    This paper presents results from the High Efficiency Solar Panel Experiment (HESP) flown on the Combined Release and Radiation Effects Satellite (CRRES). The on-orbit solar cell degradation is correlated with the proton and electron environments. Comparisons between gallium arsenide germanium (GaAs/Ge) and silicon (Si) solar cells are presented, and results from three different annealing methods of like GaAs solar cells are compared

  5. 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...

  6. Temperature dependent electroreflectance study of CdTe solar cells

    International Nuclear Information System (INIS)

    Cadmium telluride is a promising material for large scale photovoltaic applications. In this paper we study CdS/CdTe heterojunction solar cells with electroreflectance spectroscopy. Both CdS and CdTe layers in solar cells were grown sequentially without intermediate processing by the close-space sublimation method. Electroreflectance measurements were performed in the temperature range of T = 100–300 K. Two solar cells were investigated with conversion efficiencies of 4.1% and 9.6%. The main focus in this work was to study the temperature dependent behavior of the broadening parameter and the bandgap energy of CdTe thin film in solar cells. Room temperature bandgap values of CdTe were Eg = 1.499 eV and Eg = 1.481 eV for higher and lower efficiency solar cells, respectively. Measured bandgap energies are lower than for single crystal CdTe. The formation of CdTe1−xSx solid solution layer on the surface of CdTe is proposed as a possible cause of lower bandgap energies. - Highlights: ► Temperature dependent electroreflectance measurements of CdS/CdTe solar cells ► Investigation of junction properties between CdS and CdTe ► Formation of CdTe1− xSx solid solution layer in the junction area

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

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

    Solano, Manuel E.; Barber, Greg D.; Lakhtakia, Akhlesh; Faryad, Muhammad; Monk, Peter B.; Mallouk, Thomas E.

    2015-09-01

    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. 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.

  10. Plastic solar cells : understanding the special additive

    OpenAIRE

    van Franeker, Jacobus J.; Janssen, René A.J.

    2015-01-01

    Solar cells use freely available sunlight to make electricity. At the present time, solar electricity does not come cheap, because solar panels are rather expensive. Now imagine that we could reduce costs by printing solar panels like we print newspapers! We can do just that with plastic solar cells. In this article, we explain the basic working principles of these novel plastic solar cells and then show how a stunning threefold increase in solar energy efficiency can be achieved by including...

  11. 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…

  12. Description of an Immersed Photovoltaic Concentrating Solar Power System

    OpenAIRE

    Falbel, Gerald

    1998-01-01

    Recent advancements in photovoltaic solar cells made from Gallium Arsenide (GaAs) have shown that with concentration ratios greater than one solar constant, overall efficiencies up to 23% can be achieved. A second issue applicable to solar power systems for spacecraft is the cost driver, which requires that the efficiency/weight ratio be improved so that solar panels with high output, weighing less, will reduce payload weights, which, in turn, reduces launch costs. This has resulted in a "Fig...

  13. Cadmium induces autophagy through ROS-dependent activation of the LKB1-AMPK signaling in skin epidermal cells

    International Nuclear Information System (INIS)

    Cadmium is a toxic heavy metal which is environmentally and occupationally relevant. The mechanisms underlying cadmium-induced autophagy are not yet completely understood. The present study shows that cadmium induces autophagy, as demonstrated by the increase of LC3-II formation and the GFP-LC3 puncta cells. The induction of autophagosomes was directly visualized by electron microscopy in cadmium-exposed skin epidermal cells. Blockage of LKB1 or AMPK by siRNA transfection suppressed cadmium-induced autophagy. Cadmium-induced autophagy was inhibited in dominant-negative AMPK-transfected cells, whereas it was accelerated in cells transfected with the constitutively active form of AMPK. mTOR signaling, a negative regulator of autophagy, was downregulated in cadmium-exposed cells. In addition, cadmium generated reactive oxygen species (ROS) at relatively low levels, and caused poly(ADP-ribose) polymerase-1 (PARP) activation and ATP depletion. Inhibition of PARP by pharmacological inhibitors or its siRNA transfection suppressed ATP reduction and autophagy in cadmium-exposed cells. Furthermore, cadmium-induced autophagy signaling was attenuated by either exogenous addition of catalase and superoxide dismutase, or by overexpression of these enzymes. Consequently, these results suggest that cadmium-mediated ROS generation causes PARP activation and energy depletion, and eventually induces autophagy through the activation of LKB1-AMPK signaling and the down-regulation of mTOR in skin epidermal cells. - Highlights: → Cadmium, a toxic heavy metal, induces autophagic cell death through ROS-dependent activation of the LKB1-AMPK signaling. → Cadmium generates intracellular ROS at low levels and this leads to severe DNA damage and PARP activation, resulting in ATP depletion, which are the upstream events of LKB1-AMPK-mediated autophagy. → This novel finding may contribute to further understanding of cadmium-mediated diseases.

  14. 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.

  15. 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.

  16. 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 t

  17. Biomimetic Dye Aggregate Solar Cells

    OpenAIRE

    Marek, Peter L.

    2012-01-01

    A biomimetic self-assembling dye, which forms aggregates that mimic the natural light-harvesting system of special photosynthetic active bacteria, has been investigated towards its applicability to solar cells. This fully synthetic dye, self-assembles to orderly structured nano- to micrometer sized rod-shaped aggregates, which might improve solar cells based on conventional organic dyes. In order to use the full potential of the dye aggregates, the self-assembly needed to be controlled and a ...

  18. Graphene Applications in Solar Cells

    Directory of Open Access Journals (Sweden)

    JIANG Li-Li, LU Xiong

    2012-11-01

    Full Text Available Graphene has attracted much attention in fields such as physics, chemistry, and materials science, because of its unique properties and potential applications. Interests in graphene applications in solar cells have been motivated to meet the demand of improving the photovoltaic performance. Graphene applications in solar cells, such as graphene based transparent conducting electrodes, photoanodes, and accepter materials, are reviewed systematically. The further prospects and improvement of graphene applications are also discussed.

  19. Plasma Etching Improves Solar Cells

    Science.gov (United States)

    Bunyan, S. M.

    1982-01-01

    Etching front surfaces of screen-printed silicon photovoltaic cells with sulfur hexafluoride plasma found to increase cell performance while maintaining integrity of screen-printed silver contacts. Replacement of evaporated-metal contacts with screen-printed metal contacts proposed as one way to reduce cost of solar cells for terrestrial applications.

  20. Cadmium Impairs p53 Activity in HepG2 Cells.

    Science.gov (United States)

    Urani, C; Melchioretto, P; Fabbri, M; Bowe, G; Maserati, E; Gribaldo, L

    2014-01-01

    Cadmium and cadmium compounds are contaminants of the environment, food, and drinking water and are important constituents of cigarette smoke. Cd exposure has also been associated with airborne particulate CdO and with Cd-containing quantum dots in medical therapy. Adverse cadmium effects reported in the literature have stimulated during recent years an ongoing discussion to better elucidate cadmium outcomes at cell and molecular level. The present work is designed to gain an insight into the mechanism of p53 impairment at gene and protein level to understand Cd-induced resistance to apoptosis. We used a hepatoma cell line (HepG2) derived from liver, known to be metal responsive. At genotoxic cadmium concentrations no cell cycle arrest was observed. The p53 at gene and protein level was not regulated. Fluorescence images showed that p53 was correctly translocated into the nucleus but that the p21(Cip1/WAF-1), a downstream protein of p53 network involved in cell cycle regulation, was not activated at the highest cadmium concentrations used. The miRNAs analysis revealed an upregulation of mir-372, an miRNA able to affect p21(Cip1/WAF-1) expression and promote cell cycle progression and proliferation. The role of metallothioneins and possible conformational changes of p53 are discussed. PMID:25101185

  1. 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.

  2. 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.

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

    Science.gov (United States)

    Kluz, Thomas; Cohen, Lisa; Shen, Steven S.; Costa, Max

    2016-01-01

    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. PMID:27186882

  4. Comparison of manufactured and modeled solar cell

    OpenAIRE

    Strachala, D.; Hylský, J.

    2015-01-01

    The aim of the work is to compare the model of monocrystalline silicon solar cell in PC1D with the real solar cell structure in terms of using a model in manufacture process. Real solar cell was firstly measured and analyzed to determine input parameters for a simulation and then realized in free available PC1D software. Degree of conformity of modeled and real solar cell was in the end established for basic prediction of solar cell parameters before manufacturing process.

  5. 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. PMID:26376087

  6. 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.

  7. Cadmium toxicity: Effects on cytoskeleton, vesicular trafficking and cell wall construction

    OpenAIRE

    Wan, Lichuan; Zhang, Haiyan

    2012-01-01

    Cadmium is a well-known environmental pollutant with distinctly toxic effects on plants. It can displace certain essential metals from a wealth of metalloproteins, and thus disturb many normal physiological processes and cause severe developmental aberrant. The harmful effects of cadmium stress include, but are not limited to: reactive oxygen species overproduction, higher lipid hydroperoxide contents, and chloroplast structure change, which may lead to cell death. Plants have developed diver...

  8. Divergence to apoptosis from ROS induced cell cycle arrest: Effect of cadmium

    International Nuclear Information System (INIS)

    Recently, the role of cadmium (Cd) in immunosupression has gained importance. Nevertheless, the signaling pathways underlying cadmium-induced immune cell death remains largely unclear. In accordance to our previous in vivo report, and to evaluate the further details of the mechanism, we have investigated the effects of cadmium (CdCl2, H2O) on cell cycle regulation and apoptosis in splenocytes in vitro. Our results have revealed that reactive oxygen species (ROS) and p21 are involved in cell cycle arrest in a p53 independent manner but late hour apoptotic response was accompanied by the p53 up-regulation, loss of mitochondrial transmembrane potential (MTP), down-regulation of Bcl-xl, activation of caspase-3 and release of cytochrome c (Cyt c). However, pifithrin alfa (PFT-α), an inhibitor of p53, fails to rescue the cells from the cadmium-induced cell cycle arrest but prevents Bcl-xl down-regulation and loss of Δψm, which indicates that there is an involvement of p53 in apoptosis. In contrast, treatment with N-acetyl cysteine (NAC) can prevent cell cycle arrest and p21 up-regulation at early hours. Although it is clear that, NAC has no effect on apoptosis, p53 expression and MPT changes at late stage events. Taken together, we have demonstrated that cadmium promotes ROS generation, which potently initiates the cell cycle arrest at early hours and finally induces p53-dependent apoptosis at later part of the event.

  9. Comparison of fluorescent down-shifting layers for increasing the efficiency of CdS/CdTe solar cells

    OpenAIRE

    Parel, Thomas; Fang, Liping; Chu, Xishu; Danos, Lefteris; Markvart, Tom

    2011-01-01

    The poor spectral response of some Cadmium Sulfide/Cadmium Telluride (CdTe/CdS) solar cells in the UV/blue part of the spectrum can be improved through down-shifting of light using fluorescent dyes. A fluorescent down-shifting structure absorbs UV/blue light and emits it at a longer wavelength where the External Quantum Efficiency (EQE) of the solar cell is significantly higher. This study compares fluorescent structures with different dyes and different concentrations, some benefiting from r...

  10. Scientific Approach to Renewable Energy Through Solar Cells

    Science.gov (United States)

    Rao, M. C.

    Renewable energy is increasingly viewed as critically important globally. Solar cells convert the energy of the sun into electricity. The method of converting solar energy to electricity is pollution free, and appears a good practical solution to the global energy problems. Energy policies have pushed for different technologies to decrease pollutant emissions and reduce global climate change. Photovoltaic technology, which utilizes sunlight to generate energy, is an attractive alternate energy source because it is renewable, harmless and domestically secure. Transparent conducting metal oxides, being n-type were used extensively in the production of heterojunction cells using p-type Cu2O. The long held consensus is that the best approach to improve cell efficiency in Cu2O-based photovoltaic devices is to achieve both p- and n-type Cu2O and thus p-n homojunction of Cu2O solar cells. Silicon, which, next to oxygen, is the most represented element in the earth's crust, is used for the production of monocrystalline silicon solar cells. Silicon is easily obtained and processed and it is not toxic and does not form compounds that would be environmentally harmful. In contemporary electronic industry silicon is the main semiconducting element. Thin-film cadmium telluride (CdTe) solar cells are the basis of a significant technology with major commercial impact on solar energy production. Polycrystalline thin-film solar cells such as CuInSe2 (CIS), Cu (In, Ga) Se2 (CIGS) and CdTe compound semiconductors are important for terrestrial applications because of their high efficiency, long-term stable performance and potential for low-cost production. Highest record efficiencies of 19.2% for CIGS and 16.5% for CdTe have been achieved.

  11. Indentation fracture of gallium arsenide

    OpenAIRE

    Pouvreau, Cédric; GIOVANOLA, Jacques; Breguet, Jean-Marc

    2008-01-01

    The scribe and break technique (or dicing) is a widely employed method in the industry of semiconductors to separate infrared laser diodes made from gallium arsenide (GaAs). The scribing step allows to create a precursor crack which is then propagated during the breaking step, along preferential {110} cleavage planes of GaAs. The main drawback of the scribing process is that it generates a lot of undesirable cracks and particles that degrade the performances of devices. In this dissertation, ...

  12. The effect of different solar simulators on the measurement of short-circuit current temperature coefficients

    Science.gov (United States)

    Curtis, H. B.; Hart, R. E., Jr.

    1982-01-01

    Gallium arsenide solar cells are considered for several high temperature missions in space. Both near-Sun and concentrator missions could involve cell temperatures on the order of 200 C. Performance measurements of cells at elevated temperatures are usually made using simulated sunlight and a matched reference cell. Due to the change in bandgap with increasing temperature at portions of the spectrum where considerable simulated irradiance is present, there are significant differences in measured short circuit current at elevated temperatures among different simulators. To illustrate this, both experimental and theoretical data are presented for gallium arsenide cells.

  13. Fabrication of CdTe solar cells by laser-driven physical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Compaan, A.; Bhat, A.; Tabory, C.; Liu, S.; Nguyen, M.; Aydinli, A.; Tsien, L.H.; Bohn, R.G. (Toledo Univ., OH (USA). Dept. of Physics and Astronomy)

    1991-05-01

    Polycrystalline cadmium sulfide-cadmium telluride heterojunction solar cells were fabricated for the first time using a laser-driven physical vapor deposition method. An XeCl excimer laser was used to deposit both of the II-VI semiconductor layers in a single vacuum chamber from pressed powder targets. Results are presented from optical absorption. Raman scattering, X-ray diffraction, and electrical characterization of the films. Solar cells were fabricated by deposition onto SnO{sub 2}-coated glass with top contacts produced by gold evaporation. Device performance was evaluated from the spectral quantum efficiency and current-voltage measurements in the dark and with air mass 1.5 solar illumination. (orig.).

  14. Characterization of multicrystalline solar cells

    International Nuclear Information System (INIS)

    The evaluation and assessment of the performance of photovoltaic (PV) cells in terms of measurable parameters requires the measurement of the current as a function of voltage, temperature, intensity, wind speed and spectrum. Most noticeable of all these parameters in the PV conversion efficiency η, defined as the maximum electrical power Pmax produced by the PV cell divided by the incident photon power Pin which is measured with respect to standard test conditions (Sc). These conditions refer to the spectrum (AM 1.5), solar radiation intensity (1000 Wm-2), cell temperature (25 ± 2 degree C) and wind speed (2 mph). Tests under STC are carried out in the laboratory at a controlled environment. There have been several studies that analyze uncertainties in the laboratory measurement of solar cell efficiencies using different solar simulators and their transference to operational situations. Our preliminary results demonstrate that the short circuit current (ISC) of the solar cell decreases when irradiance is less than 1000 Wm-2 irrespective of the working temperature of the cell

  15. Morphology of polymer solar cells

    DEFF Research Database (Denmark)

    Böttiger, Arvid P.L.

    the morphology of the active layer of the solar cells when produced with water based inks using R2R coating. Using a broad range of scattering and imaging techniques, cells coated with water based inks were investigated, and compared to their spin coated counterpart. Two challenges to be addressed were small...... as a function of polymer, type of ink, annealing etc. Ptychography is a new state of the art X-ray imaging technique based on coherent scattering. Together with Scanning X-ray Transmission Microscopy (STXM) it has been used in this study to inspect the morphology of the active layer taken from working solar...

  16. 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.

  17. Current-Enhanced Quantum Well Solar Cells

    Institute of Scientific and Technical Information of China (English)

    LOU Chao-Gang; SUN Qiang; XU Jun; ZHANG Xiao-Bing; LEI Wei; WANG Bao-Ping; CHEN Wen-Jun; QIAO Zai-Xiang

    2006-01-01

    We present the experimental results that demonstrate the enhancement of the short-circuit current of quantum well solar cells. The spectral response shows that the introduction of quantum wells extends the absorption spectrum of solar cells. The current densities under different truncated spectrums significantly increase, showing that quantum well solar cells are suitable to be the middle cells of GaInP/GaAs/Ge triple-junction solar cells to increase their overall conversion efficiency.

  18. Characterization and evaluation of cadmium indate photocatalysts for solar hydrogen conversion

    Science.gov (United States)

    Thornton, Jason M.

    Alternative energy sources are needed to respond to the continued increase in the global energy needs and a potential decrease in the future supplies of fossil fuels. Solar hydrogen conversion in which sunlight is harnessed to split water into H2 fuel and O2 is a promising source of energy because it is renewable and produces no CO2. A number of semiconducting oxide materials have shown promise for overall water splitting for the generation of hydrogen over the years. In this work we focus on the synthesis and analysis of undoped and C-doped cadmium indate (CdIn2O 4) thin films and nanoparticle powders, and their evaluation for hydrogen evolution via water splitting. The catalyst was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-vis, scanning electron microscopy (SEM), and BET surface adsorption measurements. Spray and sol-gel pyrolysis methods were used for the synthesis of the materials. Doping C into CdIn 2O4 leads to enhancement in light absorption and the band gap was determined to be 2.3 eV in the nanoparticle powders. Carbon doping improves the photocurrent density by 33% and the H2 evolution rate by a factor of two. The performance of C-doped CdIn2O4 were optimized with respect to several synthetic parameters, including the In:Cd molar ratio and glucose concentration, calcination temperature, and the film thickness while the nanoparticles were additionally optimized to F127 concentration and platinum cocatalyst loading. Hydrogen generation activity was evaluated under UV-visible irradiation without the use of a sacrificial reagent and using bandpass filters the quantum efficiency was determined. Compared to platinized TiO2 in methanol C-CdIn2O4 showed a 4-fold increase in hydrogen production. The material was capable of hydrogen generation using visible light only and with good efficiency even at 510 nm. Using natural sunlight illumination, the material evolved hydrogen at a rate of 17 micromol h-1. These studies show

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

    OpenAIRE

    Son, Young-Ok; Wang, Lei; Poyil, Pratheeshkumar; Budhraja, Amit; Hitron, J. Andrew; Zhang, Zhuo; Lee, Jeong-Chae; Shi, Xianglin

    2012-01-01

    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 ind...

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

    Institute of Scientific and Technical Information of China (English)

    Tebekeme Okoko; Diepreye Ere

    2012-01-01

    Objective: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. Methods:The macrophage cell line U937 was treated with cadmium (0.1μmol/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 (10μmol/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. Results:It revealed that the anthocynanin-rich extract significantly (P <0.05) increased the viability of the cells which was suppressed by cadmium when compared to quercetin dihydrate. The extract also reduced the cadmium-mediated production of the markers of macrophage-activation when compared to quercetin dihydrate. In both experiments, the activity of the extract was concentration-dependent (P <0.05). Conclusion:The findings show that H. 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.

  1. Silicon for Solar Cells

    OpenAIRE

    Søiland, Anne Karin

    2005-01-01

    This thesis work consists of two parts, each with a different motivation. Part II is the main part and was partly conducted in industry, at ScanWafer ASA’s plant no.2 in Glomfjord.The large growth in the Photo Voltaic industry necessitates a dedicated feedstock for this industry, a socalled Solar Grade (SoG) feedstock, since the currently used feedstock rejects from the electronic industry can not cover the demand. Part I of this work was motivated by this urge for a SoG- feedstock. It was a ...

  2. Organic solar cells: Going green

    Science.gov (United States)

    Luo, Guoping; Wu, Hongbin

    2016-02-01

    High-performance polymer solar cells are normally processed with halogenated solvents, which are toxic and hazardous. Now, high power-conversion efficiency in bulk-heterojunction devices is achieved by using a non-toxic hydrocarbon solvent through an environmentally friendly processing route.

  3. 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.

  4. 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.

  5. Solar-Cell Slide Rule

    Science.gov (United States)

    Yamakawa, K. A.

    1983-01-01

    Slide rule relates efficiency, impurity types, impurity concentrations, and process types. Solar cell slide rule calculations are determination of allowable impurity concentration for nonredistributive process, determination of impurity buildup factor for redistributive process and determination of allowable impurity concentration for redistributive process.

  6. 1.7 MeV电子辐照对CdTe太阳电池电流传输特性影响的图谱分析%Spectral Analysis of the Effects of 1.7 MeV Electron Irradiation on the Current Transfer Characteristic of Cadmium Telluride Solar Cells

    Institute of Scientific and Technical Information of China (English)

    田金秀; 曾广根; 何绪林; 张静全; 武莉莉; 李卫; 黎兵; 王文武; 冯良桓

    2014-01-01

    研究了1.7 MeV的电子辐照对具有Anti-radiation glass/ITO/ZnO/CdS/CdTe/ZnTe/ZnTe∶Cu/Ni结构的碲化镉多晶薄膜太阳电池器件性能的影响。抗辐照玻璃的使用,有效防止了普通玻璃受辐照后性能变化对测试结果的影响。利用光、暗I-V ,C-V ,QE ,AS等测试手段,分析了包括开路电压、短路电流、转换效率在内的电池性能。通过对比研究暗电流密度、分析了辐照对电池电流传输特性的影响。辐照后短路电流下降很大,电池效率明显降低。反向饱和电流密度有所增加,表明太阳电池的pn结特性受到损伤,而二极管理想因子几乎不变,说明太阳电池电流的输运机制未发生了变化。量子效率曲线证明是由于太阳电池结区损伤影响了光生载流子的收集。辐照使载流子浓度下降为原来的40.6%。导纳谱研究最终发生辐照会引入Cd2+缺陷能级,其位置为 Et -Ev =(0.58±0.02)eV ,俘获截面为1.78×10-16 cm2,表明辐照会影响光生载流子的产生,增加了载流子复合的概率,使得反向暗电流增大,最终导致电池的短路电流衰减。%The effects of device performance of 1.7 MeV electron irradiation on cadmium telluride polycrystal-line 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) ,ad-mittance spectrum (AS) and other testing methods were used to analyze cells performance such as the open-cir-cuit voltage (Voc) ,short-circuit current (Isc) ,fill factor (FF) and conversion efficiency (η) .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

  7. Nanowire-based All Oxide Solar Cells

    OpenAIRE

    Yang, Peidong

    2009-01-01

    We present an all-oxide solar cell fabricated from vertically oriented zinc oxide nanowires and cuprous oxide nanoparticles. Our solar cell consists of vertically oriented n-type zinc oxide nanowires, surrounded by a film constructed from p-type cuprous oxide nanoparticles. Our solution-based synthesis of inexpensive and environmentally benign oxide materials in a solar cell would allow for the facile production of large-scale photovoltaic devices. We found that the solar cell performance is ...

  8. Electromagnetic approach to ultrathin solar cell efficiencies

    OpenAIRE

    Niv, A.; Gharghi, M.; Abrams, Z. R.; Gladden, C.; Zhang, X.

    2011-01-01

    Current methods for evaluating solar cell efficiencies cannot be applied to extremely thin cells where phenomena from the realm of near field optics prevail. We overcome this problem by offering a rigorous electromagnetic calculation of solar cell efficiencies based on the fluctuation dissipation theorem. Our approach is demonstrated by calculating the efficiency of a GaAs solar cell with an Au back reflector for thicknesses well below the typical wavelength of the solar flux. It is shown tha...

  9. Perovskite solar cells: an emerging photovoltaic technology

    OpenAIRE

    Nam-Gyu Park

    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....

  10. 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.

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

    Science.gov (United States)

    Krumschnabel, Gerhard; Ebner, Hannes L; Hess, Michael W; Villunger, Andreas

    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 96-120h 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

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

    International Nuclear Information System (INIS)

    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

  13. 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

  14. Structure and electrical characterization of gallium arsenide nanowires with different V/III ratio growth parameters

    Energy Technology Data Exchange (ETDEWEB)

    Muhammad, R.; Ahamad, R. [Sustainability Research Alliance, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Ibrahim, Z.; Othaman, Z. [Physic Department, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia)

    2014-03-05

    Gallium arsenide (GaAs) nanowires were grown vertically on GaAs(111)B substrate by gold-assisted using metal-organic chemical vapour deposition. Field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and conductivity atomic force microscopy (CAFM) analysis were carried out to investigate the effects of V/III ratio on structural properties and current-voltage changes in the wires. Results show that GaAs NWs grow preferably in the wurtzite crystal structure than zinc blende crystal structure with increasing V/III ratio. Additionally, CAFM studies have revealed that zincblende nanowires indicate ohmic characteristic compared to oscillation current occurred for wurtzite structures. The GaAs NWs with high quality structures are needed in solar cells technology for trapping energy that directly converts of sunlight into electricity with maximum capacity.

  15. The efficiency limit of CH3NH3PbI3 perovskite solar cells

    Science.gov (United States)

    Sha, Wei E. I.; Ren, Xingang; Chen, Luzhou; Choy, Wallace C. H.

    2015-06-01

    With the consideration of photon recycling effect, the efficiency limit of methylammonium lead iodide (CH3NH3PbI3) perovskite solar cells is predicted by a detailed balance model. To obtain convincing predictions, both AM 1.5 spectrum of Sun and experimentally measured complex refractive index of perovskite material are employed in the detailed balance model. The roles of light trapping and angular restriction in improving the maximal output power of thin-film perovskite solar cells are also clarified. The efficiency limit of perovskite cells (without the angular restriction) is about 31%, which approaches to Shockley-Queisser limit (33%) achievable by gallium arsenide (GaAs) cells. Moreover, the Shockley-Queisser limit could be reached with a 200 nm-thick perovskite solar cell, through integrating a wavelength-dependent angular-restriction design with a textured light-trapping structure. Additionally, the influence of the trap-assisted nonradiative recombination on the device efficiency is investigated. The work is fundamentally important to high-performance perovskite photovoltaics.

  16. The efficiency limit of CH3NH3PbI3 perovskite solar cells

    International Nuclear Information System (INIS)

    With the consideration of photon recycling effect, the efficiency limit of methylammonium lead iodide (CH3NH3PbI3) perovskite solar cells is predicted by a detailed balance model. To obtain convincing predictions, both AM 1.5 spectrum of Sun and experimentally measured complex refractive index of perovskite material are employed in the detailed balance model. The roles of light trapping and angular restriction in improving the maximal output power of thin-film perovskite solar cells are also clarified. The efficiency limit of perovskite cells (without the angular restriction) is about 31%, which approaches to Shockley-Queisser limit (33%) achievable by gallium arsenide (GaAs) cells. Moreover, the Shockley-Queisser limit could be reached with a 200 nm-thick perovskite solar cell, through integrating a wavelength-dependent angular-restriction design with a textured light-trapping structure. Additionally, the influence of the trap-assisted nonradiative recombination on the device efficiency is investigated. The work is fundamentally important to high-performance perovskite photovoltaics

  17. Solar cells in abundance

    International Nuclear Information System (INIS)

    This article takes a look at the rapidly growing market for photovoltaic systems and the production facilities needed to meet increasing demands. Trends in the construction of manufacturing facilities are quoted as showing that facilities will be attaining a similar size to that found in the automotive industry. The author quotes that production capacities are growing much faster than market demands and that prices on the market are not competitive with other electricity prices. Markets with strong growth are noted, as are others with high administrative impediments and resulting slower growth of installed power. Reduced governmental funding in Germany is commented on. Also, the availability of sufficient silicon is examined. The pressure on costs is considered as being positive, as sinking costs will soon make solar power more competitive on the power market.

  18. Film adhesion in amorphous silicon solar cells

    Indian Academy of Sciences (India)

    A R M Yusoff; M N Syahrul; K Henkel

    2007-08-01

    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 effect of tie coats on film adhesion.

  19. Investigation on Silicon Thin Film Solar Cells

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The preparation, current status and trends are investigated for silicon thin film solar cells. The advantages and disadvantages of amorphous silicon thin film, polycrystalline silicon thin film and mono-crystalline silicon thin film solar cells are compared. The future development trends are pointed out. It is found that polycrystalline silicon thin film solar cells will be more promising for application with great potential.

  20. Prenatal cadmium exposure alters postnatal immune cell development and function

    International Nuclear Information System (INIS)

    Cadmium (Cd) is generally found in low concentrations in the environment due to its widespread and continual use, however, its concentration in some foods and cigarette smoke is high. Although evidence demonstrates that adult exposure to Cd causes changes in the immune system, there are limited reports of immunomodulatory effects of prenatal exposure to Cd. This study was designed to investigate the effects of prenatal exposure to Cd on the immune system of the offspring. Pregnant C57Bl/6 mice were exposed to an environmentally relevant dose of CdCl2 (10 ppm) and the effects on the immune system of the offspring were assessed at two time points following birth (2 and 7 weeks of age). Thymocyte and splenocyte phenotypes were analyzed by flow cytometry. Prenatal Cd exposure did not affect thymocyte populations at 2 and 7 weeks of age. In the spleen, the only significant effect on phenotype was a decrease in the number of macrophages in male offspring at both time points. Analysis of cytokine production by stimulated splenocytes demonstrated that prenatal Cd exposure decreased IL-2 and IL-4 production by cells from female offspring at 2 weeks of age. At 7 weeks of age, splenocyte IL-2 production was decreased in Cd-exposed males while IFN-γ production was decreased from both male and female Cd-exposed offspring. The ability of the Cd-exposed offspring to respond to immunization with a S. pneumoniae vaccine expressing T-dependent and T-independent streptococcal antigens showed marked increases in the levels of both T-dependent and T-independent serum antibody levels compared to control animals. CD4+FoxP3+CD25+ (nTreg) cell percentages were increased in the spleen and thymus in all Cd-exposed offspring except in the female spleen where a decrease was seen. CD8+CD223+ T cells were markedly decreased in the spleens in all offspring at 7 weeks of age. These findings suggest that even very low levels of Cd exposure during gestation can result in long term detrimental

  1. Prenatal cadmium exposure alters postnatal immune cell development and function

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, Miranda L.; Holásková, Ida; Elliott, Meenal; Brundage, Kathleen M.; Schafer, Rosana; Barnett, John B., E-mail: jbarnett@hsc.wvu.edu

    2012-06-01

    Cadmium (Cd) is generally found in low concentrations in the environment due to its widespread and continual use, however, its concentration in some foods and cigarette smoke is high. Although evidence demonstrates that adult exposure to Cd causes changes in the immune system, there are limited reports of immunomodulatory effects of prenatal exposure to Cd. This study was designed to investigate the effects of prenatal exposure to Cd on the immune system of the offspring. Pregnant C57Bl/6 mice were exposed to an environmentally relevant dose of CdCl{sub 2} (10 ppm) and the effects on the immune system of the offspring were assessed at two time points following birth (2 and 7 weeks of age). Thymocyte and splenocyte phenotypes were analyzed by flow cytometry. Prenatal Cd exposure did not affect thymocyte populations at 2 and 7 weeks of age. In the spleen, the only significant effect on phenotype was a decrease in the number of macrophages in male offspring at both time points. Analysis of cytokine production by stimulated splenocytes demonstrated that prenatal Cd exposure decreased IL-2 and IL-4 production by cells from female offspring at 2 weeks of age. At 7 weeks of age, splenocyte IL-2 production was decreased in Cd-exposed males while IFN-γ production was decreased from both male and female Cd-exposed offspring. The ability of the Cd-exposed offspring to respond to immunization with a S. pneumoniae vaccine expressing T-dependent and T-independent streptococcal antigens showed marked increases in the levels of both T-dependent and T-independent serum antibody levels compared to control animals. CD4{sup +}FoxP3{sup +}CD25{sup +} (nTreg) cell percentages were increased in the spleen and thymus in all Cd-exposed offspring except in the female spleen where a decrease was seen. CD8{sup +}CD223{sup +} T cells were markedly decreased in the spleens in all offspring at 7 weeks of age. These findings suggest that even very low levels of Cd exposure during gestation can

  2. Research of commercial bifacial silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Tiantian; Li, Hongbo [Shanghai Solar Energy Research Center (China); Li, Wennan; Guo, Wenlin [Shanghai Perfect Energy (China); Chen, Mingbo [Shanghai Institute of Space Power-Sources (China)

    2008-07-01

    Because of the special finger shape and junction structure, bifacial silicon solar cells could receive sunlight from both sides. So the cells can absorb much sunlight, have less strict require for installation, and have higher conversion efficiency. We have done research in commercial bifacial silicon solar cells. We designed the bifacial silicon solar cells with realizable structure and high conversion efficiency. We designed and realized proper technics path, which are used to fabricate these bifacial solar cells. The boron backfield is used. The anti-reflection coating and finger contact are fabricated on both surfaces of the solar cells, so the cells have different contact structure. Meanwhile, we realized ohmic contact between finger contacts and surface of solar cells on both sides. We successfully produced the bifacial silicon solar cells with the front and rear efficiencies exceed 15% and 9%(AM1.5, 25 C), respectively, and which can be produced in large-scale. (orig.)

  3. Characterization of thin film ZnCdS/CdTe solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, O.M.; Reddy, P.S.; Naidu, B.S.; Uthanna, S.; Reddy, P.J. (Sri Venkateswara Univ., Tirupati (IN). Dept. of Physics)

    1991-11-01

    Thin films of II-VI compound semiconductors have attracted considerable interest in recent years due to their wide range of applications in the fabrication of cost effective solar cells. Among these, cadmium telluride is one of the most attractive candidates with a direct band gap of 1.5 eV which is optimum for solar energy conversion. Generally, n-CdS is used as window layer to p-CdTe to fabricate heterojunction solar cells because of its reasonable optical transparency and the ease of depositing low-resistivity films. n-ZnCdS/p-CdTe polycrystalline thin film solar cells were fabricated by laser evaporating CdTe onto sprayed ZnCdS films. The cells were characterized by studying current-voltage, capacitance-voltage and spectral response measurements. A maximum efficiency of 7.6% was observed for a cell area of 1 cm{sup 2}. (author).

  4. CdTe/CdS solar cells with transparent contacts

    Energy Technology Data Exchange (ETDEWEB)

    Birkmire, R.W.; McCandless, B.E.; Shafarman, W.N.

    1988-01-15

    Evaporated CdTe/CdS solar cells with a transparent Cu-indium tin oxide contact have been made with an efficiency greater than 8.5%. The deposition of single-phase CdTe films from a compound source required a cadmium-to-tellurium flux ratio of 1.7 incident on the substrate. To obtain the needed p-type conductivity of the CdTe films required a high temperature heat treatment in air which reduced the transmission through the CdTe film owing to the formation of a CdTeO/sub 3/ surface layer. The heating and cooling rates used for the heat treatment affected the open-circuit voltage and contact resistance of the cells. The total subband gap absorption of the entire cell is 40%-50%.

  5. High-Performance GaAs Nanowire Solar Cells for Flexible and Transparent Photovoltaics.

    Science.gov (United States)

    Han, Ning; Yang, Zai-xing; Wang, Fengyun; Dong, Guofa; Yip, SenPo; Liang, Xiaoguang; Hung, Tak Fu; Chen, Yunfa; Ho, Johnny C

    2015-09-16

    Among many available photovoltaic technologies at present, gallium arsenide (GaAs) is one of the recognized leaders for performance and reliability; however, it is still a great challenge to achieve cost-effective GaAs solar cells for smart systems such as transparent and flexible photovoltaics. In this study, highly crystalline long GaAs nanowires (NWs) with minimal crystal defects are synthesized economically by chemical vapor deposition and configured into novel Schottky photovoltaic structures by simply using asymmetric Au-Al contacts. Without any doping profiles such as p-n junction and complicated coaxial junction structures, the single NW Schottky device shows a record high apparent energy conversion efficiency of 16% under air mass 1.5 global illumination by normalizing to the projection area of the NW. The corresponding photovoltaic output can be further enhanced by connecting individual cells in series and in parallel as well as by fabricating NW array solar cells via contact printing showing an overall efficiency of 1.6%. Importantly, these Schottky cells can be easily integrated on the glass and plastic substrates for transparent and flexible photovoltaics, which explicitly demonstrate the outstanding versatility and promising perspective of these GaAs NW Schottky photovoltaics for next-generation smart solar energy harvesting devices. PMID:26284305

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

    Science.gov (United States)

    Ferain, Aline; Bonnineau, Chloé; Neefs, Ineke; Rees, Jean François; Larondelle, Yvan; Schamphelaere, Karel A C De; Debier, Cathy

    2016-08-01

    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 24h 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 protected the RTL-W1 cells against both methylmercury and cadmium; (iv) DHA enrichment significantly protected the cells against cadmium but not methylmercury; (v) AA and LA enrichment had no impact on the cell tolerance to both methylmercury and cadmium; (vi) the abundance of 20:3n-6, a metabolite of the n-6 biotransformation pathway, in

  7. INCREMENT OF EFFICIENCY OF SOLAR CELL, WITH CHANGE SHAPE AND SIZE OF SOLAR PENNAL

    OpenAIRE

    S.K. Yadav; K.L. Yadav

    2014-01-01

    -To increase the efficiency of solar system with the help of change shape and size of solar pennal and arrangement of solar cell. And falling of light energy absorbed by solar cells and also dependence of solar energy, efficiency of solar cell on the multireflections of light on the solar cells. We formed different-different shape and size of solar pennal efficiency of solar cell, the internal and external reflections of light occurs many times with high energetic beam of ligh...

  8. Silicate reduces cadmium uptake into cells of wheat.

    Science.gov (United States)

    Greger, Maria; Kabir, Ahmad H; Landberg, Tommy; Maity, Pooja J; Lindberg, Sylvia

    2016-04-01

    Cadmium (Cd) is a health threat all over the world and high Cd content in wheat causes high Cd intake. Silicon (Si) decreases cadmium content in wheat grains and shoot. This work investigates whether and how silicate (Si) influences cadmium (Cd) uptake at the cellular level in wheat. Wheat seedlings were grown in the presence or absence of Si with or without Cd. Cadmium, Si, and iron (Fe) accumulation in roots and shoots was analysed. Leaf protoplasts from plants grown without Cd were investigated for Cd uptake in the presence or absence of Si using the fluorescent dye, Leadmium Green AM. Roots and shoots of plants subjected to all four treatments were investigated regarding the expression of genes involved in the Cd uptake across the plasma membrane (i.e. LCT1) and efflux of Cd into apoplasm or vacuole from the cytosol (i.e. HMA2). In addition, phytochelatin (PC) content and PC gene (PCS1) expression were analysed. Expression of iron and metal transporter genes (IRT1 and NRAMP1) were also analysed. Results indicated that Si reduced Cd accumulation in plants, especially in shoot. Si reduced Cd transport into the cytoplasm when Si was added both directly during the uptake measurements and to the growth medium. Silicate downregulated LCT1 and HMA2 and upregulated PCS1. In addition, Si enhanced PC formation when Cd was present. The IRT1 gene, which was downregulated by Cd was upregulated by Si in root and shoot facilitating Fe transport in wheat. NRAMP1 was similarly expressed, though the effect was limited to roots. This work is the first to show how Si influences Cd uptake on the cellular level. PMID:26745394

  9. High Efficiency Polymer Solar Cells Technologies

    Institute of Scientific and Technical Information of China (English)

    Abdrhman M G; LI Hang-quan; ZHANG Li-ye; ZHOU Bing

    2006-01-01

    The conjugated polymer-based solar cell is one of the most promising devices in search of sustainable, renewable energy sources in last decade. It is the youngest field in organic solar cell research and also is certainly the fastest growing one at the moment. In addition, the key factor for polymer-based solar cells with high-efficiency is to invent new materials. Organic solar cell has attracted significant researches and commercial interest due to its low cost in fabrication and flexibility in applications. However, they suffer from relatively low conversion efficiency. The summarization of the significance and concept of high efficiency polymer solar cell technologies are presented.

  10. Hybrid emitter all back contact solar cell

    Science.gov (United States)

    Loscutoff, Paul; Rim, Seung

    2016-04-12

    An all back contact solar cell has a hybrid emitter design. The solar cell has a thin dielectric layer formed on a backside surface of a single crystalline silicon substrate. One emitter of the solar cell is made of doped polycrystalline silicon that is formed on the thin dielectric layer. The other emitter of the solar cell is formed in the single crystalline silicon substrate and is made of doped single crystalline silicon. The solar cell includes contact holes that allow metal contacts to connect to corresponding emitters.

  11. Cadmium activates extracellular signal-regulated kinase 5 in HK-2 human renal proximal tubular cells

    International Nuclear Information System (INIS)

    Highlights: ► Cadmium exposure induces ERK5 phosphorylation in HK-2 renal proximal tubular cells. ► BIX02189 treatment suppresses cadmium-induced ERK5 but not ERK1/2 phosphorylation. ► BIX02189 treatment suppresses cadmium-induced CREB and c-Fos phosphorylation. ► ERK5 activation by cadmium exposure may play an anti-apoptotic role in HK-2 cells. -- Abstract: We examined the effects of cadmium chloride (CdCl2) exposure on the phosphorylation and functionality of extracellular signal-regulated kinase 5 (ERK5), a recently identified member of the mitogen-activated protein kinase (MAPK) family, in HK-2 human renal proximal tubular cells. Following exposure to CdCl2, ERK5 phosphorylation increased markedly, but the level of total ERK5 was unchanged. ERK5 phosphorylation following CdCl2 exposure was rapid and transient, similar to the time course of ERK1/2 phosphorylation. Treatment of HK-2 cells with the MAPK/ERK kinase 5 inhibitor, BIX02189, suppressed CdCl2-induced ERK5 but not ERK1/2 phosphorylation. The CdCl2-induced increase of phosphorylated cAMP response element-binding protein (CREB) and activating transcription factor-1 (ATF-1), as well as the accumulation of mobility-shifted c-Fos protein, were suppressed by BIX02189 treatment. Furthermore, BIX02189 treatment enhanced cleavage of poly(ADP-ribose) polymerase and increased the level of cytoplasmic nucleosomes in HK-2 cells exposed to CdCl2. These findings suggest that ERK5 pathway activation by CdCl2 exposure might induce the phosphorylation of cell survival-transcription factors, such as CREB, ATF-1, and c-Fos, and may exert a partial anti-apoptotic role in HK-2 cells.

  12. Divergence to apoptosis from ROS induced cell cycle arrest: Effect of cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, Soumya; Kundu, Subhadip; Sengupta, Suman [Department of Environmental Science, University of Kalyani, West Bengal 741235 (India); Department of Zoology, University of Calcutta, Calcutta-700019, West Bengal (India); Bhattacharyya, Arindam, E-mail: arindam19@yahoo.com [Department of Environmental Science, University of Kalyani, West Bengal 741235 (India); Department of Zoology, University of Calcutta, Calcutta-700019, West Bengal (India)

    2009-04-26

    Recently, the role of cadmium (Cd) in immunosupression has gained importance. Nevertheless, the signaling pathways underlying cadmium-induced immune cell death remains largely unclear. In accordance to our previous in vivo report, and to evaluate the further details of the mechanism, we have investigated the effects of cadmium (CdCl{sub 2}, H{sub 2}O) on cell cycle regulation and apoptosis in splenocytes in vitro. Our results have revealed that reactive oxygen species (ROS) and p21 are involved in cell cycle arrest in a p53 independent manner but late hour apoptotic response was accompanied by the p53 up-regulation, loss of mitochondrial transmembrane potential (MTP), down-regulation of Bcl-xl, activation of caspase-3 and release of cytochrome c (Cyt c). However, pifithrin alfa (PFT-{alpha}), an inhibitor of p53, fails to rescue the cells from the cadmium-induced cell cycle arrest but prevents Bcl-xl down-regulation and loss of {Delta}{psi}{sub m}, which indicates that there is an involvement of p53 in apoptosis. In contrast, treatment with N-acetyl cysteine (NAC) can prevent cell cycle arrest and p21 up-regulation at early hours. Although it is clear that, NAC has no effect on apoptosis, p53 expression and MPT changes at late stage events. Taken together, we have demonstrated that cadmium promotes ROS generation, which potently initiates the cell cycle arrest at early hours and finally induces p53-dependent apoptosis at later part of the event.

  13. Cadmium uptake and sequestration kinetics in individual leaf cell protoplasts of the Cd/Zn hyperaccumulator Thlaspi caerulescens

    OpenAIRE

    Leitenmaier, Barbara; Küpper, Hendrik

    2011-01-01

    Hyperaccumulators store accumulated metals in the vacuoles of large leaf epidermal cells (storage cells). For investigating cadmium uptake, we incubated protoplasts obtained from leaves of Thlaspi caerulescens (Ganges ecotype) with a Cd-specific fluorescent dye. A fluorescence kinetic microscope was used for selectively measuring Cd-uptake and photosynthesis in different cell types, so that physical separation of cell types was not necessary. Few minutes after its addition, cadmium accumulate...

  14. 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.

  15. Use of Tunable Whole-Cell Bioreporters to Assess Bioavailable Cadmium and Remediation Performance in Soils.

    Directory of Open Access Journals (Sweden)

    Youngdae Yoon

    Full Text Available It is important to have tools to measure the bioavailability to assess the risks of pollutants because the bioavailability is defined as the portions of pollutants showing the biological effects on living organisms. This study described the construction of tunable Escherichia coli whole-cell bioreporter (WCB using the promoter region of zinc-inducible operon and its application on contaminated soils. It was verified that this WCB system showed specific and sensitive responses to cadmium rather than zinc in the experimental conditions. It was inferred that Cd(II associates stronger with ZntR, a regulatory protein of zinc-inducible operon, than other metal ions. Moreover, the expression of reporter genes, egfp and mcherry, were proportional to the concentration of cadmium, thereby being a quantitative sensor to monitor bioavailable cadmium. The capability to determine bioavailable cadmium was verified with Cd(II amended LUFA soils, and then the applicability on environmental systems was investigated with field soils collected from smelter area in Korea before and after soil-washing. The total amount of cadmium was decreased after soil washing, while the bioavailability was increased. Consequently, it would be valuable to have tools to assess bioavailability and the effectiveness of soil remediation should be evaluated in the aspect of bioavailability as well as removal efficiency.

  16. 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.

  17. Performance of thin-film Cds/CdTe solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, O.M.; Reddy, P.J. (Sri Venkateswara Univ., Tirupati (India). Dept. of Physics)

    1991-07-15

    Cadmium telluride is a very promising material for producing efficient thin-film solar cells because is has a direct bandgap of 1.5 eV, which is optimum for solar energy conversion. Many researchers have employed close space vapour transport, screen printing, thermal evaporation and electrochemical deposition techniques for the fabrication of Cds/CdTe solar cells, and have obtained a conversion efficiency of about 10%. In this investigation polycrystalline thin-film Cds/CdTe solar cells were fabricated by employing a laser evaporation technique for the deposition of CdTe films. The cells were characterized by studying the current-voltage, capacitance-voltage and spectral response measurements. (Author).

  18. Silicon Carbide Solar Cells Investigated

    Science.gov (United States)

    Bailey, Sheila G.; Raffaelle, Ryne P.

    2001-01-01

    The semiconductor silicon carbide (SiC) has long been known for its outstanding resistance to harsh environments (e.g., thermal stability, radiation resistance, and dielectric strength). However, the ability to produce device-quality material is severely limited by the inherent crystalline defects associated with this material and their associated electronic effects. Much progress has been made recently in the understanding and control of these defects and in the improved processing of this material. Because of this work, it may be possible to produce SiC-based solar cells for environments with high temperatures, light intensities, and radiation, such as those experienced by solar probes. Electronics and sensors based on SiC can operate in hostile environments where conventional silicon-based electronics (limited to 350 C) cannot function. Development of this material will enable large performance enhancements and size reductions for a wide variety of systems--such as high-frequency devices, high-power devices, microwave switching devices, and high-temperature electronics. These applications would supply more energy-efficient public electric power distribution and electric vehicles, more powerful microwave electronics for radar and communications, and better sensors and controls for cleaner-burning, more fuel-efficient jet aircraft and automobile engines. The 6H-SiC polytype is a promising wide-bandgap (Eg = 3.0 eV) semiconductor for photovoltaic applications in harsh solar environments that involve high-temperature and high-radiation conditions. The advantages of this material for this application lie in its extremely large breakdown field strength, high thermal conductivity, good electron saturation drift velocity, and stable electrical performance at temperatures as high as 600 C. This behavior makes it an attractive photovoltaic solar cell material for devices that can operate within three solar radii of the Sun.

  19. High-efficiency, thin-film cadmium telluride photovoltaic cells. Annual subcontract report, 20 January 1994--19 January 1995

    Energy Technology Data Exchange (ETDEWEB)

    Compaan, A.D.; Bohn, R.G.; Rajakarunanayake, Y. [Toledo Univ., OH (United States)

    1995-08-01

    This report describes work performed to develop and optimize the process of radio frequency (RF) sputtering for the fabrication of thin-film solar cells on glass. The emphasis is on CdTe-related materials including CdTe, CdS, ZnTe, and ternary alloy semiconductors. Pulsed laser physical vapor deposition (LPVD) was used for exploratory work on these materials, especially where alloying or doping are involved, and for the deposition of cadmium chloride layers. For the sputtering work, a two-gun sputtering chamber was implemented, with optical access for monitoring temperature and growth rate. We studied the optical and electrical properties of the plasmas produced by two different kinds of planar magnetron sputter guns with different magnetic field configurations and strengths. Using LPVD, we studied alloy semiconductors such as CdZnTe and heavily doped semiconductors such as ZnTe:Cu for possible incorporation into graded band gap CdTe-based photovoltaic devices.

  20. Work Station For Inverting Solar Cells

    Science.gov (United States)

    Feder, H.; Frasch, W.

    1982-01-01

    Final work station along walking-beam conveyor of solar-array assembly line turns each pretabbed solar cell over, depositing it back-side-up onto landing pad, which centers cell without engaging collector surface. Solar cell arrives at inverting work station collector-side-up with two interconnect tabs attached to collector side. Cells are inverted so that second soldering operation takes place in plain view of operator. Inversion protects collector from damage when handled at later stages of assembly.

  1. 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.

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

    International Nuclear Information System (INIS)

    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 Cd2+ 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

  3. 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.

  4. Solution processing of next-generation nanocrystal solar cells

    Science.gov (United States)

    van Embden, J.; Chesman, A. S. R.; Duffy, N. W.; Della Gaspera, E.; Jasieniak, J. J.

    2013-12-01

    Next-generation solar cells will be fabricated from low-cost and earth abundant elements, using processes that are amenable to printing on a variety of light-weight substrates. The utilization of compositionally and structurally controlled colloidal nanocrystals as building blocks for such devices fulfills these criteria. Our recent efforts in developing kesterite Cu2ZnSnS4 (CZTS) nanocrystals, one of the most promising materials to emerge in this area, enable the deposition of CZTS thin-films directly from a variety of solution-processed methods. Nanocrystalline thin films possess poor electronic properties, which precludes their use in solar cell devices. In order to overcome this, thermal treatment steps under an atmosphere of vaporous selenium are applied to induce large scale crystallite growth and the production of selenized CZTSSe films. This process results in a highly photoactive p-type layer. The n-type cadmium sulfide layer is also deposited from solution using chemical bath deposition. We will discuss each of these accomplishments in detail, highlighting the significant challenges that need to be overcome in order to fabricate working CZTSSe thin film solar cells.

  5. Cadmium Induced Cell Apoptosis, DNA Damage, Decreased DNA Repair Capacity, and Genomic Instability during Malignant Transformation of Human Bronchial Epithelial Cells

    OpenAIRE

    Zhou, Zhiheng; Wang, Caixia; Liu, Haibai; Huang, Qinhai; Wang, Min; Lei, Yixiong

    2013-01-01

    Cadmium and its compounds are well-known human carcinogens, but the mechanisms underlying the carcinogenesis are not entirely understood. Our study was designed to elucidate the mechanisms of DNA damage in cadmium-induced malignant transformation of human bronchial epithelial cells. We analyzed cell cycle, apoptosis, DNA damage, gene expression, genomic instability, and the sequence of exons in DNA repair genes in several kinds of cells. These cells consisted of untreated control cells, cells...

  6. 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.

  7. Solar Energy Cell with Rare Earth Film

    Institute of Scientific and Technical Information of China (English)

    Li Baojun; Yang Tao; Zhou Yao; Zhou Meng; Fu Xiliang; Fu Li

    2004-01-01

    The characteristic of the solar energy cell with the rare earth film according to theory of molecular structure was introduced.When sunlight shines, the molecules of the rare earth film can absorb energy of the photon and jump to the excited state from the basic state, and play a role in storing solar energy.When sunlight do not shine, the electron of the excited state returns to the basic state, the rare earth film can automatically give out light and shine to surface of the solar cell, which can make solar cell continuously generate electric current.The rare earth film can absorb direct,scattering sunlight, and increase density of solar energy to reach surface of the solar cell, and play focusing function.The rare earth film can bear 350 ~ 500 ℃, which make the solar cell be able to utilize the focusing function system.Because after luminescence of the rare earth film, it can release again the absorbed solar energy through 1 ~ 8 h, and play a role in storing solar energy; The solar cell with the rare-earth film can generate electricity during night and cloudy days, and remarkably increase efficiency of the solar cell.

  8. Effects of long-term low-dose cadmium exposure on genomic DNA methylation in human embryo lung fibroblast cells

    International Nuclear Information System (INIS)

    Cadmium is a toxic transition metal of continuing occupational and environmental concern. As a well-recognized human carcinogen, its carcinogenic mechanisms are still poorly understood. Cadmium has long been considered a non-genotoxic carcinogen and thought to act through epigenetic mechanisms. In the present study, we tested the effects of long-term low-dose cadmium exposure on DNA methylation in human embryo lung fibroblast (HLF) cells. After 2 months of exposure to 0-1.5 μmol/L cadmium, both the level of genomic DNA methylation and the enzyme activity of DNA methyltransferases (DNMTs) were increased in a concentration-related manner. Moreover, our results showed that cadmium exposure up-regulated the mRNA levels of DNMT1, DNMT3a and DNMT3b at higher concentrations. We further tested the growth dynamics of HLF cells, and observed significantly elevated growth rates, decreased cell population of G0/G1-phase and increased cell population of S-phase at 0.9, 1.2, and 1.5 μmol/L concentrations. Our study indicated that long-term low-dose cadmium exposure could disrupt DNA methylation, which may be one of the possible underlying carcinogenic mechanisms of cadmium

  9. 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...... polymers were degraded resulting in acceleration factors in the range of 19-55. This shows that concentrated sunlight can be used as qualitatively to determine the lifetime of polymers under highly accelerated conditions....

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

    Science.gov (United States)

    Samson, Mil'shtein; Anup, Pillai; Shiv, Sharma; Garo, Yessayan

    2013-12-01

    For many years the main focus of R&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 / m2 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 / m2. This will allow the novel solar cell to produce electricity at a cost of 0.06-0.08 / kW-hr.

  11. 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.

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

    International Nuclear Information System (INIS)

    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 / m2 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 / m2. This will allow the novel solar cell to produce electricity at a cost of $0.06–0.08 / kW-hr

  13. The effect of process conditions on the performance of epitaxial InP solar cells

    Science.gov (United States)

    Borrego, J. M.; Ghandi, S. K.

    1991-01-01

    Indium phosphide solar cells have a higher resistance to electron irradiation than Si or GaAs cells of comparable junction depth. As a result, there is much interest in the use of this material for space applications. Cells of this material were made in bulk InP by a number of techniques, including ion implantation, direct diffusion in sealed ampoules, and by open tube diffusion. However, it is generally considered that the epitaxial approach will be superior to all of these techniques. The epitaxy of InP is considerably more difficult than that of gallium arsenide, for a number of reasons. Perhaps the most important is the fact that the native oxides of Indium are extremely difficult to remove, as compared to that of Gallium. In addition, thermal treatments for the desorption of these oxides often result in the formation of phosphorus vacancies and free indium on the surface. Thus, inadequate sample preparation before epitaxy, poor reactor cleaning procedures, or poor transition procedures between the growth of successive layers, all give rise to trap phenomena and to high interface recombination velocities. Moreover, the lifetime of the grown material is dominated by the occurrence of native defects, so that it is a strong function of growth parameters. These problems are of special interest to the fabrication of solar cells, where long life-time, combined with the absence of traps, is highly desirable. A study of this problem is described using a non-invasive diagnostic technique which was developed.

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

    International Nuclear Information System (INIS)

    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

  15. Nanostructured Interfaces in Hybrid Solar Cells

    OpenAIRE

    Weickert, Jonas

    2014-01-01

    Excitonic solar cells are an emerging technology which holds the great promise of generating clean and sustainable photovoltaic power at lower cost than conventional silicon solar cells. In excitonic solar cells, the light is absorbed by organic semiconductors and dye molecules, which typically exhibit higher exciton binding energies than inorganic semiconductors. Therefore, free charge carriers can be generated only at interfaces between donor and acceptor materials. These interfaces can pro...

  16. Including excitons in semiconductor solar cell modelling

    OpenAIRE

    Burgelman, Marc; Minnaert, Ben

    2005-01-01

    Excitons are marginally important in classical semiconductor device physics, and their treatment is not included in standard solar cell modelling. However, in organic semiconductors and solar cells, the role of excitons is essential, as the primary effect of light absorption is exciton generation, and free electrons and holes are created by exciton dissociation. First steps to include excitons in solar cell modelling were presented by Green 1996 and Zhang 1998. Their model was restricted to a...

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

    International Nuclear Information System (INIS)

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

  18. 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.

  19. Amorphous silicon based solar cells

    OpenAIRE

    Al Tarabsheh, Anas

    2007-01-01

    This thesis focuses on the deposition of hydrogenated amorphous silicon (a-Si:H) films bymeans of plasma enhanced chemical vapour deposition (PECVD). This technique allows the growth of device quality a-Si:H at relatively low deposition temperatures, below 140 °C and, therefore, enables the use of low-cost substrates, e.g. plastic foils. The maximum efficiencies of a-Si:H solar cells in this work are η= 6.8 % at a deposition temperature Tdep = 180 °C and η = 4.9 % at a deposition ...

  20. CdS/CdTe solar cells by the screen-printing-sintering technique: Fabrication, photovoltaic properties and applications

    Energy Technology Data Exchange (ETDEWEB)

    Ikegami, Seiji

    1988-01-15

    CdS/CdTe solar cells are fabricated on a borosilicate glass substrate by successively repeating screen printing and sintering (heating) in a belt furnace pastes of CdS, cadmium plus tellurium, carbon, silver plus indium and silver. In various sizes of solar cells, the highest efficiencies have been achieved for II-VI compound solar cells. The present solar cells have a spectral sensitivity up to a slightly longer wavelength than that of the usual CdS/CdTe solar cells. This may be due to the formation of CdS/sub x/Te/sub 1-x/ mixed crystals during the sintering of CdTe. In reliability tests under rooftop conditions, no remarkable change in the output power was observed in encapsulated solar cells over 800 days. From the results of accelerated tests on unencapsulated solar cells, a waterproof-type structure for the present solar cell module is required. The present solar cells and modules are now on the market for both indoor use and outdoor use; this is the first experience of the use of II-VI compound solar cells. Efforts to expand their application are being continued.

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

    Science.gov (United States)

    Chen, Ying Ying; Zhu, Jin Yong; Chan, King Ming

    2014-12-01

    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(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. PMID:25456234

  2. Three-Terminal Amorphous Silicon Solar Cells

    OpenAIRE

    Cheng-Hung Tai; Chu-Hsuan Lin; Chih-Ming Wang; Chun-Chieh Lin

    2011-01-01

    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...

  3. Theoretical investigation on heterojunction solar cell

    International Nuclear Information System (INIS)

    The study of thin film solar cells has proved that the surface is rough. A two-dimensional method based on the integral equation technique to analyse thin film solar cells has been developed by DeMey et al. In this paper we present our analysis of a thin film solar cell using the above techniques. Variation of the minority carrier concentration, the saturation current and the junction current of the solar cell with surface roughness is presented. (author). 8 refs, 4 figs

  4. 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. PMID:26489525

  5. Experimental solar cells on the SUNSAT microsatellite

    Energy Technology Data Exchange (ETDEWEB)

    Hardingham, C.; Simpson, J.; Wood, S.; Cross, T.A. [EEV Ltd., Chelmsford (United Kingdom); Uys, J.F. [Univ. of Stellenbosch (South Africa)

    1997-12-31

    SUNSAT is an experimental microsatellite, built by the University of Stellenbosch in South Africa. It is completely powered by 4 body-mounted GaAs solar panels, manufactured by EEV Ltd. One solar panel comprises 9 separate strings of experimental solar cells. This paper describes the design and manufacture of the experimental panel, data collection and analysis, and anticipates the experimental flight data.

  6. 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

  7. Environmental aspects of solar cell modules. Summary report

    International Nuclear Information System (INIS)

    Four major types of solar cell modules, based on respectively multicrystalline silicon, amorphous silicon, cadmium telluride and copper indium selenide are reviewed with special attention to future expected technology developments. For each module type an assessment is made of the potential environmental impacts in case of large scale implementation of the technology. In principle, the entire module life cycle is taken into consideration: from resource mining, via module production and module utilization until module decommissioning and waste handling. For each module type the following aspects are discussed: energy requirements and energy pay-back time, material requirements and resource depletion, environmental emissions, waste handling, possibilities for recycling of modules, occupational health and safety and external safety. 2 figs., 16 tabs., 1 appendix, 36 refs

  8. Polycrystalline thin-film solar cells and modules

    Energy Technology Data Exchange (ETDEWEB)

    Ullal, H.S.; Stone, J.L.; Zweibel, K.; Surek, T.; Mitchell, R.L.

    1991-12-01

    This paper describes the recent technological advances in polycrystalline thin-film solar cells and modules. Three thin film materials, namely, cadmium telluride (CdTe), copper indium diselenide (CuInSe{sub 2}, CIS) and silicon films (Si-films) have made substantial technical progress, both in device and module performance. Early stability results for modules tested outdoors by various groups worldwide are also encouraging. The major global players actively involved in the development of the these technologies are discussed. Technical issues related to these materials are elucidated. Three 20-kW polycrystalline thin-film demonstration photovoltaic (PV) systems are expected to be installed in Davis, CA in 1992 as part of the Photovoltaics for Utility-Scale Applications (PVUSA) project. This is a joint project between the US Department of Energy (DOE), Pacific Gas and Electric (PG&E), Electric Power Research Institute (EPRI), California Energy Commission (CEC), and a utility consortium.

  9. Polycrystalline thin-film solar cells and modules

    Energy Technology Data Exchange (ETDEWEB)

    Ullal, H.S.; Stone, J.L.; Zweibel, K.; Surek, T.; Mitchell, R.L.

    1991-12-01

    This paper describes the recent technological advances in polycrystalline thin-film solar cells and modules. Three thin film materials, namely, cadmium telluride (CdTe), copper indium diselenide (CuInSe{sub 2}, CIS) and silicon films (Si-films) have made substantial technical progress, both in device and module performance. Early stability results for modules tested outdoors by various groups worldwide are also encouraging. The major global players actively involved in the development of the these technologies are discussed. Technical issues related to these materials are elucidated. Three 20-kW polycrystalline thin-film demonstration photovoltaic (PV) systems are expected to be installed in Davis, CA in 1992 as part of the Photovoltaics for Utility-Scale Applications (PVUSA) project. This is a joint project between the US Department of Energy (DOE), Pacific Gas and Electric (PG E), Electric Power Research Institute (EPRI), California Energy Commission (CEC), and a utility consortium.

  10. Dynamics of mercury, cadmium and vanadium in cultured bovine kidney cells: an examination of relationships to cytotoxicity and cell function

    International Nuclear Information System (INIS)

    The objective of this study was to partially define the in vitro cellular response to mercury, cadmium and vanadium insult. A bovine kidney cell line served as the model system for examining the relationship of the cellular dynamics of metal accumulation and distribution to cytotoxicity. Additionally, biochemical marker functions were monitored in surviving cells to determine the importance of metal uptake and distribution to cell functionality. Each metal (HgCl2, CdCl2, and Na3VO4) elicited a concentration-related cytotoxicity which was correlated to the cellular metal burden. Multiphasic accumulation kinetics were established for mercury and vanadium; cadmium was accumulated in a linear fashion. Subcellular metal distribution was independent of both the extra-cellular metal concentration and the degree of cytotoxicity. Biochemical marker functions indicated a toxicity-related decrease in cell functionality in surviving cells for all metals

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

    Institute of Scientific and Technical Information of China (English)

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

    2015-01-01

    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 þ 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 þ 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 com-partmentation of Cd into vacuoles also contributes to the Glu-alleviated Cd toxicity. Taken together, we demonstrated that Glu-alleviated Cd toxicity is mediated through increas-ing Cd fixation in the root cell wall and sequestration into the vacuoles.

  12. 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)

  13. Advances in thin-film solar cells

    CERN Document Server

    Dharmadasa, I M

    2012-01-01

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

  14. 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

  15. 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.

  16. Effects of cadmium ions on the initial stage of translation and the cell death in mouse liver

    OpenAIRE

    Sadauskienė, Ilona; Ivanov, Leonid; Lesauskaitė, Vaiva; Ivanovienė, Laima; Gailevičiūtė, Rasa; Karčiauskaitė, Dovilė; Rodovičius, Hiliaras

    2005-01-01

    Objective. To evaluate in vivo and in vitro effects of cadmium ions on the activities of mice liver tRNALeu and leucyl-tRNA synthetase and on the type of liver cells death. Material and methods. White laboratory mice were intoxicated by intraperitoneal injection of cadmium chloride solution (1.6 mg cadmium ions/1 kg of body weigh). Total tRNAs were isolated by adding ethanol and isopropanol into the phenol-deproteinized supernatant of mouse liver homogenate. Post-mitochondrial fraction of ...

  17. Perovskite solar cells: an emerging photovoltaic technology

    Directory of Open Access Journals (Sweden)

    Nam-Gyu Park

    2015-03-01

    Full Text Available 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. However, the liquid-based perovskite solar cell receives little attention because of its stability issues, including instant dissolution of the perovskite in a liquid electrolyte. A long-term, stable, and high efficiency (∼10% perovskite solar cell was developed in 2012 by substituting the solid hole conductor with a liquid electrolyte. Efficiencies have quickly risen to 18% in just 2 years. Since PCE values over 20% are realistically anticipated with the use of cheap organometal halide perovskite materials, perovskite solar cells are a promising photovoltaic technology. In this review, the opto-electronic properties of perovskite materials and recent progresses in perovskite solar cells are described. In addition, comments on the issues to current and future challenges are mentioned.

  18. Transport boundary conditions for solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Volovichev, I.N.; Velazquez-Perez, J.E. [Departamento Fisica Aplicada, Universidad de Salamanca, Plaza de la Merced, E-37008 Salamanca (Spain); Gurevich, Yu.G. [Departamento de Fisica, CINVESTAV-IPN, Av. IPN 2508, Apartado Postal 14 740, Mexico DF 07000 (Mexico)

    2009-01-15

    Boundary conditions (BCs) to the Poisson and transport equations for stationary transport processes of nonequilibrium carriers in semiconductor structures, including solar cells, are formulated. The applicability of the resulting BCs for solar cells consisting of several various materials (metals, bipolar semiconductors, including ones in the quasineutrality approach) and their structures are analyzed for both closed and open circuit conditions. (author)

  19. Scaling up ITO-Free solar cells

    NARCIS (Netherlands)

    Galagan, Y.O.; Coenen, E.W.C.; Zimmermann, B.; Slooff, L.H.; Verhees, W.J.H.; Veenstra, S.C.; Kroon, J.M.; Jørgensen, M.; Krebs, F.C.; Andriessen, H.A.J.M.

    2014-01-01

    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 and th

  20. Theory of bifacial sunlit silicon solar cells

    Science.gov (United States)

    Gasparyan, Ferdinand V.; Aroutiounian, Vladimir M.

    2001-11-01

    Bifacial sunlit solar cells made of silicon p+nn+ structures are investigated theoretically. It is shown that the short circuit current, open circuit voltage, fill-factor and efficiency strongly depend on both p+n junction parameters and n+n isojunction. Possibilities of manufacturing high-efficiency bifacial solar cells using silicon p+nn+ structures are discussed.

  1. Screen Printed Metallization of Silicon Solar Cells

    OpenAIRE

    Govaerts, R.; Van Overstraeten, R.; Mertens, R.; Ph. Lauwers; Frisson, L.

    1980-01-01

    This paper presents a screen printing process for the metallization of silicon solar cells. The physics and construction of a classical solar cell are reviewed. The results obtained with a screen printing process are comparable with other, more expensive technologies. This technology does not introduce an additional contact resistance on silicon. The process optimization and the influence of different parameters are discussed.

  2. Predicted solar cell edge radiation effects

    International Nuclear Information System (INIS)

    The Advanced Solar Cell Orbital Test (ASCOT) will test six types of solar cells in a high energy proton environment. During the design of the experiment a question was raised about the effects of proton radiation incident on the edge of the solar cells and whether edge radiation shielding was required. Historical geosynchronous data indicated that edge radiation damage is not detectable over the normal end of life solar cell degradation; however because the ASCOT radiation environment has a much higher and more energetic fluence of protons, considerably more edge damage is expected. A computer analysis of the problem was made by modeling the expected radiation damage at the cell edge and using a network model of small interconnected solar cells to predict degradation in the cell's electrical output. The model indicated that the deepest penetration of edge radiation was at the top of the cell near the junction where the protons have access to the cell through the low density cell/cover adhesive layer. The network model indicated that the cells could tolerate high fluences at their edge as long as there was high electrical resistance between the edge radiated region and the contact system on top of the cell. The predicted edge radiation related loss was less than 2% of maximum power for GaAs/Ge solar cells. As a result, no edge radiation protection was used for ASCOT

  3. 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.

  4. Organic Based Solar Cells with Morphology Control

    DEFF Research Database (Denmark)

    Andersen, Thomas Rieks

    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......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 to be...... 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 of the...

  5. Methodologies for high efficiency perovskite solar cells

    Science.gov (United States)

    Park, Nam-Gyu

    2016-06-01

    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.

  6. 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.

  7. Effects of high-temperature annealing on ultra-thin CdTe solar cells

    International Nuclear Information System (INIS)

    High-temperature annealing (HTA), a process step prior to vapor cadmium chloride (VCC) treatment, has been found to be useful for improving the crystallinity of CdTe films and the efficiency of ultra-thin CdTe solar cells. Scanning electron microscopy, optical absorption, photoluminescence measurements and analyses on photoluminescence results using spectral deconvolution reveal that the additional HTA step produces substantial grain growth and reduces grain boundary defects. It also reduces excessive sulfur diffusion across the junction that can occur during the VCC treatment. The HTA step helps to produce pinhole-free CdTe films and reduce electrical shorts in ultra-thin CdTe solar cells. An efficiency of about 11.6% has been demonstrated for ultra-thin CdS/CdTe solar cells processed with HTA step.

  8. Electrochemical monitoring of phytochelatin accumulation in Nicotiana tabacum cells exposed to sub-cytotoxic and cytotoxic levels of cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Fojta, Miroslav [Laboratory of Biophysical Chemistry and Molecular Oncology, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno (Czech Republic)]. E-mail: fojta@ibp.cz; Fojtova, Miloslava [Laboratory of Molecular Epigenetics, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno (Czech Republic); Havran, Ludek [Laboratory of Biophysical Chemistry and Molecular Oncology, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno (Czech Republic); Pivonkova, Hana [Laboratory of Biophysical Chemistry and Molecular Oncology, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno (Czech Republic); Dorcak, Vlastimil [Laboratory of Biophysical Chemistry and Molecular Oncology, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno (Czech Republic); Sestakova, Ivana [J. Heyrovsky Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejskova 3, 182 23 Prague 8 (Czech Republic)

    2006-02-03

    Cadmium belongs to the most dangerous environmental pollutants among the toxic heavy metals seriously affecting vital functions in both animal and plant cells. It has been previously shown that cadmium ions at 50-100 {mu}M concentrations caused tobacco BY-2 (TBY-2) cells to enter apoptosis within several days of exposure. Phytochelatins (PCs), the 'plant metallothioneins', are cysteine-rich peptides involved in detoxification of heavy metals in plants. The PCs are synthesized in response to the heavy metal exposure. In this paper, we utilized electrochemical analysis to monitor accumulation of PCs in the TBY-2 cells exposed to cadmium ions. Measurements of a characteristic PC signal at mercury electrode in the presence of cobalt ions made it possible to detect changes in the cellular PC levels during the time of cultivation, starting from 30 min after exposure. Upon TBY-2 cultivation in the presence of cytotoxic cadmium concentrations, the PC levels remarkably increased during the pre-apoptotic phase and reached a limiting value at cultivation times coinciding with apoptosis trigger. The PC level observed for a sub-cytotoxic cadmium concentration (10 {mu}M) was about three-times lower than that observed for the 50 or 100 {mu}M cadmium ions after 5 days of exposure. We show that using a simple electrochemical analysis, synthesis of PCs in plant cells can be easily followed in parallel with other tests of the cellular response to the toxic heavy metal stress.

  9. Over-expression of human endosulfatase-1 exacerbates cadmium-induced injury to transformed human lung cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Huiying [Department of Molecular Biomedical Sciences, Center for Comparative Molecular Translational Research, College of Veterinary Medicine, NC State University, Raleigh, NC 27607 (United States); Department of Environmental and Molecular Toxicology, College of Agriculture and Life Sciences, NC State University, Raleigh, NC 27695 (United States); Newman, Donna R. [Department of Molecular Biomedical Sciences, Center for Comparative Molecular Translational Research, College of Veterinary Medicine, NC State University, Raleigh, NC 27607 (United States); Bonner, James C. [Department of Environmental and Molecular Toxicology, College of Agriculture and Life Sciences, NC State University, Raleigh, NC 27695 (United States); Sannes, Philip L., E-mail: philip_sannes@ncsu.edu [Department of Molecular Biomedical Sciences, Center for Comparative Molecular Translational Research, College of Veterinary Medicine, NC State University, Raleigh, NC 27607 (United States)

    2012-11-15

    Environmental exposure to cadmium is known to cause damage to alveolar epithelial cells of the lung, impair their capacity to repair, and result in permanent structural alterations. Cell surface heparan sulfate proteoglycans (HSPGs) can modulate cell responses to injury through their interactions with soluble effector molecules. These interactions are often sulfate specific, and the removal of sulfate groups from HS side chains could be expected to influence cellular injury, such as that caused by exposure to cadmium. The goal of this study was to define the role 6-O-sulfate plays in cellular responses to cadmium exposure in two pulmonary epithelial cancer cell lines (H292 and A549) and in normal human primary alveolar type II (hAT2) cells. Sulfate levels were modified by transduced transient over-expression of 6-O-endosulfatase (HSulf-1), a membrane-bound enzyme which specifically removes 6-O-sulfate groups from HSPG side chains. Results showed that cadmium decreased cell viability and activated apoptosis pathways at low concentrations in hAT2 cells but not in the cancer cells. HSulf-1 over-expression, on the contrary, decreased cell viability and activated apoptosis pathways in H292 and A549 cells but not in hAT2 cells. When combined with cadmium, HSulf-1 over-expression further decreased cell viability and exacerbated the activation of apoptosis pathways in the transformed cells but did not add to the toxicity in hAT2 cells. The finding that HSulf-1 sensitizes these cancer cells and intensifies the injury induced by cadmium suggests that 6-O-sulfate groups on HSPGs may play important roles in protection against certain environmental toxicants, such as heavy metals. -- Highlights: ► Primary human lung alveolar type 2 (hAT2) cells and H292 and A549 cells were used. ► Cadmium induced apoptosis in hAT2 cells but not in H292 or A549 cells. ► HSulf-1exacerbates apoptosis induced by cadmium in H292 and A549 but not hAT2 cells.

  10. 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.

  11. High-Temperature Solar Cell Development

    Science.gov (United States)

    Landis, Geoffrey A.; Raffaelle, Ryne P.; Merritt, Danielle

    2004-01-01

    The vast majority of satellites and near-earth probes developed to date have relied upon photovoltaic power generation. If future missions to probe environments close to the sun will be able to use photovoltaic power, solar cells that can function at high temperatures, under high light intensity, and high radiation conditions must be developed. For example, the equilibrium temperature of a Mercury surface station will be about 450 C, and the temperature of solar arrays on the proposed "Solar Probe" mission will extend to temperatures as high as 2000 C (although it is likely that the craft will operate on stored power rather than solar energy during the closest approach to the sun). Advanced thermal design principles, such as replacing some of the solar array area with reflectors, off-pointing, and designing the cells to reflect rather than absorb light out of the band of peak response, can reduce these operating temperature somewhat. Nevertheless, it is desirable to develop approaches to high-temperature solar cell design that can operate under temperature extremes far greater than today's cells. Solar cells made from wide bandgap (WBG) compound semiconductors are an obvious choice for such an application. In order to aid in the experimental development of such solar cells, we have initiated a program studying the theoretical and experimental photovoltaic performance of wide bandgap materials. In particular, we have been investigating the use of GaP, SiC, and GaN materials for space solar cells. We will present theoretical results on the limitations on current cell technologies and the photovoltaic performance of these wide-bandgap solar cells in a variety of space conditions. We will also give an overview of some of NASA's cell developmental efforts in this area and discuss possible future mission applications.

  12. 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.

  13. 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 curre

  14. 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.

  15. 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.

  16. The efficiency limit of CH{sub 3}NH{sub 3}PbI{sub 3} perovskite solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Sha, Wei E. I. [Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong (China); The University of Hong Kong Shenzhen Institute of Research and Innovation (HKU-SIRI), Shenzhen 518057 (China); Ren, Xingang; Chen, Luzhou; Choy, Wallace C. H., E-mail: chchoy@eee.hku.hk [Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong (China)

    2015-06-01

    With the consideration of photon recycling effect, the efficiency limit of methylammonium lead iodide (CH{sub 3}NH{sub 3}PbI{sub 3}) perovskite solar cells is predicted by a detailed balance model. To obtain convincing predictions, both AM 1.5 spectrum of Sun and experimentally measured complex refractive index of perovskite material are employed in the detailed balance model. The roles of light trapping and angular restriction in improving the maximal output power of thin-film perovskite solar cells are also clarified. The efficiency limit of perovskite cells (without the angular restriction) is about 31%, which approaches to Shockley-Queisser limit (33%) achievable by gallium arsenide (GaAs) cells. Moreover, the Shockley-Queisser limit could be reached with a 200 nm-thick perovskite solar cell, through integrating a wavelength-dependent angular-restriction design with a textured light-trapping structure. Additionally, the influence of the trap-assisted nonradiative recombination on the device efficiency is investigated. The work is fundamentally important to high-performance perovskite photovoltaics.

  17. Recent Advancements and Techniques in Manufacture of Solar Cells: Organic Solar Cells

    Directory of Open Access Journals (Sweden)

    B. Naga Venkata Sai Ganesh,

    2013-03-01

    Full Text Available The major problem faced by the society is power crisis. All the non-renewable resources like fossil fuelsnecessary for producing power are being used excessively, which might result a day in future where, the world might godark due to lack of power producing resources. Usage of renewable resources like solar energy can be a solution to thisproblem. Solar cells invented to overcome this problem show rigidity in their structure which is a drawback. Inorganicsolar cells are rigid and can be mounted only on rooftops. Hence only upper surface of buildings are utilized. In this paperwe bring out a new era or solar cells- organic solar cells, which are flexible. These organic solar cells offer the bestsolution for the above problem for a tradeoff of efficiency. This paper briefs the manufacturing technique of solar cellsfrom plastic i.e. ,organic polymers, their architecture, the working process of solar energy production from the organicsolar cells with their ease of usage

  18. Modulating Exciton Dynamics in Composite Nanocrystals for Excitonic Solar Cells.

    Science.gov (United States)

    Concina, Isabella; Manzoni, Cristian; Grancini, Giulia; Celikin, Mert; Soudi, Afsoon; Rosei, Federico; Zavelani-Rossi, Margherita; Cerullo, Giulio; Vomiero, Alberto

    2015-07-01

    Quantum dots (QDs) represent one of the most promising materials for third-generation solar cells due to their potential to boost the photoconversion efficiency beyond the Shockley-Queisser limit. Composite nanocrystals can challenge the current scenario by combining broad spectral response and tailored energy levels to favor charge extraction and reduce energy and charge recombination. We synthesized PbS/CdS QDs with different compositions at the surface of TiO2 nanoparticles assembled in a mesoporous film. The ultrafast photoinduced dynamics and the charge injection processes were investigated by pump-probe spectroscopy. We demonstrated good injection of photogenerated electrons from QDs to TiO2 in the PbS/CdS blend and used the QDs to fabricate solar cells. The fine-tuning of chemical composition and size of lead and cadmium chalcogenide QDs led to highly efficient PV devices (3% maximum photoconversion efficiency). This combined study paves the way to the full exploitation of QDs in next-generation photovoltaic (PV) devices. PMID:26266724

  19. 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.

  20. Thin-film crystalline silicon solar cells

    CERN Document Server

    Brendel, Rolf

    2011-01-01

    This introduction to the physics of silicon solar cells focuses on thin cells, while reviewing and discussing the current status of the important technology. An analysis of the spectral quantum efficiency of thin solar cells is given as well as a full set of analytical models. This is the first comprehensive treatment of light trapping techniques for the enhancement of the optical absorption in thin silicon films.

  1. Semi-transparent polymer solar cells

    OpenAIRE

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

  2. Growth Inhibition Occurs Independently of Cell Mortality in Tomato (Solanum lycopersicum) Exposed to High Cadmium Concentrations

    Institute of Scientific and Technical Information of China (English)

    Christine Delpérée; Stanley Lutts

    2008-01-01

    In order to analyze the adaptation potential of tomato shoots to a sudden increase in Cd concentration, tomato plants (Solanum lycopersicum L. var. Ailsa Craig) were exposed under controlled environmental conditions to a high dose of this heavy metal (250 μM CdCl2>) in nutrient solution for 7 and 14 d. Both root and shoot growth was completely inhibited but all plants remained alive until the end of the treatment. Cell viability remained unaffected but the activity of the mitochondrial alternative pathway was stimulated by Cd stress at the expense of the cytochrome pathway. Cadmium concentration was higher in roots than in shoots and a decrease In the rate of net Cd translocation was noticed during the second week of stress. Cadmium decreased both leaf conductance (g1>) and chlorophyll concentration. However, the effect on net CO2 assimilation remained limited and soluble sugars accumulated in leaves. Photochemical efficiency of PSll (FvlFm) was not affected despite a decrease in the number of reaction centers and an inhibition of electron transfer to acceptors of PSII. It is concluded that tomato shoot may sustain short term exposure to high doses of cadmium despite growth inhibition. This property implies several physiological strategies linked to both avoidance and tolerance mechanisms.

  3. Photoelectrochemical Solar Cells Based on Chitosan Electroylte

    Institute of Scientific and Technical Information of China (English)

    M.H.A.Buraidah; A.K.Arof

    2007-01-01

    1 Results ITO-ZnTe/Chitosan-NH4I-I2/ITO photoelectrochemical solar cells have been fabricated and characterized by current-voltage characteristics.In this work,the ZnTe thin film was prepared by electrodeposition on indium-tin-oxide coated glass.The chitosan electrolyte consists of NH4I salt and iodine.Iodine was added to provide the I3-/I- redox couple.The PEC solar cell was fabricated by sandwiching an electrolyte film between the ZnTe semiconductor and ITO conducting glass.The area of the solar cell...

  4. Inorganic caesium lead iodide perovskite solar cells

    OpenAIRE

    Eperon, GE; Paterno', GM; Sutton, RJ; Zampetti, A.; Haghighirad, A; Cacialli, F.; Snaith, H.

    2015-01-01

    The vast majority of perovskite solar cell research has focused on organic-inorganic lead trihalide perovskites. Herein, we present working inorganic CsPbI3 perovskite solar cells for the first time. CsPbI3 normally resides in a yellow non-perovskite phase at room temperature, but by careful processing control and development of a low-temperature phase transition route we have stabilised the material in the black perovskite phase at room temperature. As such, we have fabricated solar cell dev...

  5. 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 and...

  6. Process monitoring in solar cell manufacturing

    International Nuclear Information System (INIS)

    In this paper, the authors describe a new method that is capable of on-line monitoring of several solar cell process steps such as texturing, AR coatings, and metal contact properties. The measurement technique is rapid and specifically designed for solar cells and wafers. The system implementing this new concept is named ''PV Reflectometer.'' The idea was originally conceived several years ago and the principle of the method has been demonstrated for some simple cases. Recently, this method has been improved to be more suitable for commercial applications. For completeness, the paper first includes a brief review of the process control requirements and the common monitoring methods in solar cell production

  7. 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.

  8. Solar cell preparation in thin silicon membranes

    Energy Technology Data Exchange (ETDEWEB)

    Libezny, M.; Poortmans, J.; Caymax, M.; Beaucarne, G.; Laureys, W.; Nijs, J. [IMEC, Leuven (Belgium)

    1997-12-31

    Solar cells prepared in a thin ({approx} 30 {micro}m) crystalline silicon membrane with a supporting frame allow an evaluation of the potential of c-Si thin film cells on cheap substrates. In the same time, light-weight and more radiation-hard solar cells may have direct applications in space. This paper studies the fabrication process of solar cells in {approx} 30 {micro}m thick p-Si epitaxial layers, incorporating a p{sup +2}-Si etch-stop/back-surface field layer, using KOH etching. Wax, rubber and silicon nitride were tested as masking material during the etching. It was found that both wax and silicon nitride could be used as materials for masking of supporting frames for the solar cell thinning up to 30 {micro}m. However, silicon nitride does not reliably protect the frontside structure.

  9. 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.

  10. Metamorphic Epitaxy for Multijunction Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    France, Ryan M.; Dimroth, Frank; Grassman, Tyler J.; King, Richard R.

    2016-03-01

    Multijunction solar cells have proven to be capable of extremely high efficiencies by combining multiple semiconductor materials with bandgaps tuned to the solar spectrum. Reaching the optimum set of semiconductors often requires combining high-quality materials with different lattice constants into a single device, a challenge particularly suited for metamorphic epitaxy. In this article, we describe different approaches to metamorphic multijunction solar cells, including traditional upright metamorphic, state-of-the-art inverted metamorphic, and forward-looking multijunction designs on silicon. We also describe the underlying materials science of graded buffers that enables metamorphic subcells with low dislocation densities. Following nearly two decades of research, recent efforts have demonstrated high-quality lattice-mismatched multijunction solar cells with very little performance loss related to the mismatch, enabling solar-to-electric conversion efficiencies over 45%.

  11. 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

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

    International Nuclear Information System (INIS)

    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

  13. MoSe2 / Polyaniline Solar Cells

    Directory of Open Access Journals (Sweden)

    H.S. Patel

    2011-01-01

    Full Text Available Solar cells have been investigated since long for harnessing the solar energy. During this decade, a new direction has come up where in the polymers have been used in the fabrication of solar cells. Polyaniline is one of the polymers which has shown potential for its applications in heterostructure solar cells. This material is being used along with the semiconductors like InSe, TiO2, Si etc. to form the photosensitive interface. In this direction, we report our investigations on the use of Molybdenum diselenide (MoSe2 as photosensitive semiconducting material in MoSe2 / polyaniline solar cells. In this paper, the preparation of MoSe2 / polyaniline solar cells has been reported. Also, the photovoltage → photocurrent characteristics of this structure have been discussed in detail in this paper. The variation of different parameters of MoSe2 / polyaniline solar cells (like open circuit voltage, short circuit current, photoconversion efficiency and fill factor with the intensity of incident illuminations has been reported in this paper. In present case, the photocurrent density was found to be around 250 µA/cm2 with the photovoltage around 8.5 mV (which is low the photoconversion efficiency was found to be around 0.7 % along with the fill factor around 0.33. The efforts have been made to explain the low values of the photoconversion efficiency.

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

    International Nuclear Information System (INIS)

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

  15. Challenges in amorphous silicon solar cell technology

    International Nuclear Information System (INIS)

    Hydrogenated amorphous silicon is nowadays extensively used for a range of devices, amongst others solar cells. Solar cell technology has matured over the last two decades and resulted in conversion efficiencies in excess of 15%. In this paper the operation of amorphous silicon solar cells is briefly described. For tandem solar cell, amorphous silicon germanium is often used as material for the intrinsic layer of the bottom cell. This improves the red response of the cell. In order to optimize the performance of amorphous silicon germanium solar cells, profiling of the germanium concentration near the interfaces is applied. We show in this paper that the performance is strongly dependent on the width of the grading near the interfaces. The best performance is achieved when using a grading width that is as small as possible near the p-i interface and as wide as possible near the i-n interface. High-rate deposition of amorphous silicon is nowadays one of the main issues. Using the Expanding Thermal Plasma deposition method very high deposition rates can be achieved. This method has been applied for the fabrication of an amorphous silicon solar cell with a conversion efficiency of 5,8%. (authors)

  16. Key factors limiting the open circuit voltage of n(+)pp(+) indium phosphide solar cells

    Science.gov (United States)

    Goradia, Chandra; Thesling, William; Weinberg, Irving

    1991-01-01

    Solar cells made from gallium arsenide (GaAs), with a room temperature bandgap of E(sub g) = 1.43 eV have exhibited the best measured open circuit voltage (V sub OC) of 1.05 V at 1 AMO, 25 C. The material InP is in many ways similar to GaAs. A simple calculation comparing InP to GaAs then shows that solar cells made from InP, with E(sub g) = 1.35 at 300 K, should exhibit the best measured (V sub OC) of approximately 950 mV at 1 AMO, 300 K. However, to date, the best measured V(sub OC) for InP solar cells made by any fabrication method is 899 mV at AM1.5, 25 C which would translate to 912 mV at 1 AMO, 25 C. The V(sub OC) of an n(+)pp(+) InP solar cell is governed by several factors. Of these, some factors, such as the thickness and doping of the emitter and base regions, are easily controlled and can be adjusted to desired values dictated by a good performance optimizing model. Such factors were not considered. There are other factors which also govern V(sub OC), and their values are not so easily controlled. The primary ones among these are (1) the indirect or Hall-Shockley-Read lifetimes in the various regions of the cell, (2) the low-doping intrinsic carrier concentration n(sub i) of the InP material, (3) the heavy doping factors in the emitter and BSF regions, and (4) the front surface recombination velocity S(sub F). The influence of these latter factors on the V(sub OC) of the n(+)pp(+) InP solar cell and the results were used to produce a near-optimum design of the n(+)pp(+) InP solar cell.

  17. Microcrystalline silicon and micromorph tandem solar cells

    OpenAIRE

    Keppner, H.; Meier, Johannes; Torres, P.; Fischer, D.; Shah, A.

    2008-01-01

    “Micromorph” tandem solar cells consisting of a microcrystalline silicon bottom cell and an amorphous silicon top cell are considered as one of the most promising new thin-film silicon solar-cell concepts. Their promise lies in the hope of simultaneously achieving high conversion efficiencies at relatively low manufacturing costs. The concept was introduced by IMT Neuchâtel, based on the VHF-GD (very high frequency glow discharge) deposition method. The key element of the micromorph cell is t...

  18. Highly stable tandem solar cell monolithically integrating dye-sensitized and CIGS solar cells

    Science.gov (United States)

    Chae, Sang Youn; Park, Se Jin; Joo, Oh-Shim; Jun, Yongseok; Min, Byoung Koun; Hwang, Yun Jeong

    2016-01-01

    A highly stable monolithic tandem solar cell was developed by combining the heterogeneous photovoltaic technologies of dye-sensitized solar cell (DSSC) and solution-processed CuInxGa1-xSeyS1-y (CIGS) thin film solar cells. The durability of the tandem cell was dramatically enhanced by replacing the redox couple from to [Co(bpy)3]2+ /[Co(bpy)3]3+), accompanied by a well-matched counter electrode (PEDOT:PSS) and sensitizer (Y123). A 1000 h durability test of the DSSC/CIGS tandem solar cell in ambient conditions resulted in only a 5% decrease in solar cell efficiency. Based on electrochemical impedance spectroscopy and photoelectrochemical cell measurement, the enhanced stability of the tandem cell is attributed to minimal corrosion by the cobalt-based polypyridine complex redox couple. PMID:27489138

  19. A space solar cell bonding robot

    Institute of Scientific and Technical Information of China (English)

    FU Zhuang; ZHAO Yan-zheng; LIU Ren-qiang; DONG Zhi

    2006-01-01

    A space solar cell bonding robot system which consists of a three-axis Cartesian coordinate's robot,coating device,bonding device,orientation plate,and control subsystem was studied.A method,which can control the thickness of adhesive layer on the solar cell,was put forward and the mechanism was designed.Another method which can achieve the auto-bonding between thin coverglass and the space solar cell was studied and realized.It produced no air bubble in the adhesives layer under the condition of no vacuum environment,and ensures the assembly dislocation ≤0.1 mm.Compared to the conventional method,it has advantages such as no fragment exists,and no adhesives outflow onto the cover-glass and solar cells.

  20. 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...... 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 in the...

  1. 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...

  2. Toxicity of organometal halide perovskite solar cells

    Science.gov (United States)

    Babayigit, Aslihan; Ethirajan, Anitha; Muller, Marc; Conings, Bert

    2016-03-01

    In the last few years, the advent of metal halide perovskite solar cells has revolutionized the prospects of next-generation photovoltaics. As this technology is maturing at an exceptional rate, research on its environmental impact is becoming increasingly relevant.

  3. 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...

  4. Amorphous Silicon-Carbon Nanostructure Solar Cells

    Science.gov (United States)

    Schriver, Maria; Regan, Will; Loster, Matthias; Zettl, Alex

    2011-03-01

    Taking advantage of the ability to fabricate large area graphene and carbon nanotube networks (buckypaper), we produce Schottky junction solar cells using undoped hydrogenated amorphous silicon thin films and nanostructured carbon films. These films are useful as solar cell materials due their combination of optical transparency and conductance. In our cells, they behave both as a transparent conductor and as an active charge separating layer. We demonstrate a reliable photovoltaic effect in these devices with a high open circuit voltage of 390mV in buckypaper devices. We investigate the unique interface properties which result in an unusual J-V curve shape and optimize fabrication processes for improved solar conversion efficiency. These devices hold promise as a scalable solar cell made from earth abundant materials and without toxic and expensive doping processes.

  5. Electrospun Polymer-Fiber Solar Cell

    Directory of Open Access Journals (Sweden)

    Shinobu Nagata

    2013-01-01

    Full Text Available A novel electrospun polymer-fiber solar cell was synthesized by electrospinning a 1 : 2.5 weight% ratio mixture of poly[2-methoxy-5-(2-ethylhexyloxy-1,4-phenylenevinylene] (MEH-PPV and [6,6]-phenyl C61 butyric acid methyl ester (PCBM resulting in bulk heterojunctions. Electrospinning is introduced as a technique that may increase polymer solar cell efficiency, and a list of advantages of the technique applied to solar cells is discussed. The device achieved a power conversion efficiency of %. The absorption and photoluminescence of MEH-PPV nanofibers are compared to thin films of the same material. Electrospun nanofibers are discussed as a favorable structure for application in polymer solar cells.

  6. Cadmium induces neuronal cell death through reactive oxygen species activated by GADD153

    Directory of Open Access Journals (Sweden)

    Kim Seungwoo

    2013-01-01

    Full Text Available Abstract Background Cadmium(Cd, a heavy metal, which has a potent harmful effects, is a highly stress-inducible material that is robustly expressed following disruption of homeostasis in the endoplasmic reticulum (ER (so-called ER stress. The mechanism Cd induced cell death of neuroblastoma cells complex, involving cellular signaling pathways as yet incompletely defined but, in part, involving the generation of reactive oxygen species (ROS. Several studies have correlated GADD153 expression with cell death, but a mechanistic link between GADD153 and apoptosis has never been demonstrated. Results SH-SY5Y cells were treated Cd led to increase in intracellular ROS levels. ROS generation is not consistent with intracellular [Ca2+]. The exposure of neuroblastoma cells to Cd led to increase in intracellular GADD153 and Bak levels in a doses and time dependent manner. The induction of these genes by Cd was attenuated by NAC. Cd-induced apoptosis is decreased in GADD153 knockdown cells compared with normal cells. The effect of GADD153 on the binding of C/EBP to the Bak promoters were analyzed ChIP assay. Basal constitutive GADD153 recruitment to the –3,398/–3,380 region of the Bak promoter is observed in SH-SY5Y cells. Conclusions The exposure of SH-SY5Y cells to Cd led to increase in intracellular ROS levels in a doses and time dependent manner. The generation of ROS result in the induction of GADD153 is causative of cadmium-induced apoptosis. GADD153 regulates Bak expression by its binding to promoter region (between −3,398 and −3,380. Therefore, we conclude that GADD153 sensitizes cells to ROS through mechanisms that involve up-regulation of BAK and enhanced oxidant injury.

  7. Dip coated nanocrystalline CdZnS thin films for solar cell application

    Science.gov (United States)

    Dongre, J. K.; Chaturvedi, Mahim; Patil, Yuvraj; Sharma, Sandhya; Jain, U. K.

    2015-07-01

    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).

  8. 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%.

  9. Solar cells on the base of organic semiconductors

    International Nuclear Information System (INIS)

    The parameters of organic solar cells on the base of different organic semiconductors as poly epoxypropyl carbazole, copper phthalocyanine and bordeaux perylene are considered. Moreover the properties of solar cells on the base of n-GaAs and copper phthalocyanine heterostructure are described. The new technologies in the field of organic solar cells as bulk heterostructure solar cells are discussed. (author)

  10. Singlet fission: Towards efficient solar cells

    International Nuclear Information System (INIS)

    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

  11. 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.

  12. Processing of high efficiency silicon solar cells

    OpenAIRE

    Härkönen, Jaakko

    2001-01-01

    Fabrication technology of high efficiency silicon solar cells has been studied in this work. Process development work has been carried out since 1997 within a project "Development of high-efficiency low-cost silicon solar cells", which was funded by TEKES, Fortum Advanced Energy Systems and Okmetic Ltd. Co - operation with photovoltaic research group of Fortum Surface Chemistry has been very close during the project. Target of this project is to demonstrate by low cost processing technologies...

  13. Exploring nanoscale properties of organic solar cells

    OpenAIRE

    Mönch, Tobias

    2015-01-01

    The demand for electrical energy is steadily increasing. Highly efficient organic solar cells based on mixed, strongly absorbing organic molecules convert sunlight into electricity and, thus, have the potential to contribute to the worlds energy production. The continuous development of new materials during the last decades lead to a swift increase of power conversion efficiencies (PCE) of organic solar cells, recently reaching 12%. Despite these breakthroughs, the usage of highly complex...

  14. Modeling Light Trapping in Nanostructured Solar Cells

    OpenAIRE

    Ferry, Vivian E.; Polman, Albert; Atwater, Harry A.

    2011-01-01

    The integration of nanophotonic and plasmonic structures with solar cells offers the ability to control and confine light in nanoscale dimensions. These nanostructures can be used to couple incident sunlight into both localized and guided modes, enhancing absorption while reducing the quantity of material. Here we use electromagnetic modeling to study the resonances in a solar cell containing both plasmonic metal back contacts and nanostructured semiconductor top contacts, identify the local ...

  15. Molecular and cellular mechanisms of cadmium resistance in cultured cells

    Energy Technology Data Exchange (ETDEWEB)

    Grady, D.L.; Moyzis, R.K.; Hildebrand, C.E.

    1985-01-01

    Heavy metal induction of the synthesis of metallothioneins (MTs) provides an ideal model system for basic mechanistic studies of gene expression. Cell lines varying in their resistance to heavy metals have been isolated through a regime of exposure to serially increasing levels of Cd followed by clonal isolation. These cell lines have been used to examine the role of methylation and amplification in the Cd-resistant (Cd/sup r/) phenotype. It is suggested that regulation of expression of the MT genes in Cd/sup r/ Chinese hamster cells is modulated at both the transcriptional and translational levels. An analysis of the MT2 gene sequence has uncovered a potential alternative splice site in the first intron. Usage of this site would insert 3 or 12 additional amino acids between amino acids 9 and 10. Analysis of the splicing pattern of the MT2 gene transcript in cultured cells has indicated that the second intron is preferentially removed prior to first intron excision. 34 refs., 2 figs., 1 tab.

  16. Multijunction Solar Cells Optimized for the Mars Surface Solar Spectrum

    Science.gov (United States)

    Edmondson, Kenneth M.; Fetzer, Chris; Karam, Nasser H.; Stella, Paul; Mardesich, Nick; Mueller, Robert

    2007-01-01

    This paper gives an update on the performance of the Mars Exploration Rovers (MER) which have been continually performing for more than 3 years beyond their original 90-day missions. The paper also gives the latest results on the optimization of a multijunction solar cell that is optimized to give more power on the surface of Mars.

  17. Achieving High Performance Perovskite Solar Cells

    Science.gov (United States)

    Yang, Yang

    2015-03-01

    Recently, metal halide perovskite based solar cell with the characteristics of rather low raw materials cost, great potential for simple process and scalable production, and extreme high power conversion efficiency (PCE), have been highlighted as one of the most competitive technologies for next generation thin film photovoltaic (PV). In UCLA, we have realized an efficient pathway to achieve high performance pervoskite solar cells, where the findings are beneficial to this unique materials/devices system. Our recent progress lies in perovskite film formation, defect passivation, transport materials design, interface engineering with respect to high performance solar cell, as well as the exploration of its applications beyond photovoltaics. These achievements include: 1) development of vapor assisted solution process (VASP) and moisture assisted solution process, which produces perovskite film with improved conformity, high crystallinity, reduced recombination rate, and the resulting high performance; 2) examination of the defects property of perovskite materials, and demonstration of a self-induced passivation approach to reduce carrier recombination; 3) interface engineering based on design of the carrier transport materials and the electrodes, in combination with high quality perovskite film, which delivers 15 ~ 20% PCEs; 4) a novel integration of bulk heterojunction to perovskite solar cell to achieve better light harvest; 5) fabrication of inverted solar cell device with high efficiency and flexibility and 6) exploration the application of perovskite materials to photodetector. Further development in film, device architecture, and interfaces will lead to continuous improved perovskite solar cells and other organic-inorganic hybrid optoelectronics.

  18. Methods for forming group III-arsenide-nitride semiconductor materials

    Science.gov (United States)

    Major, Jo S. (Inventor); Welch, David F. (Inventor); Scifres, Donald R. (Inventor)

    2002-01-01

    Methods are disclosed for forming Group III-arsenide-nitride semiconductor materials. Group III elements are combined with group V elements, including at least nitrogen and arsenic, in concentrations chosen to lattice match commercially available crystalline substrates. Epitaxial growth of these III-V crystals results in direct bandgap materials, which can be used in applications such as light emitting diodes and lasers. Varying the concentrations of the elements in the III-V crystals varies the bandgaps, such that materials emitting light spanning the visible spectra, as well as mid-IR and near-UV emitters, can be created. Conversely, such material can be used to create devices that acquire light and convert the light to electricity, for applications such as full color photodetectors and solar energy collectors. The growth of the III-V crystals can be accomplished by growing thin layers of elements or compounds in sequences that result in the overall lattice match and bandgap desired.

  19. Effect of solar-terrestrial phenomena on solar cell's efficiency

    International Nuclear Information System (INIS)

    It is assumed that the solar cell efficiency of PV device is closely related to the solar irradiance, consider the solar parameter Global Solar Irradiance (G) and the meteorological parameters like daily data of Earth Skin Temperature (E), Average Temperature (T), Relative Humidity (H) and Dew Frost Point (D), for the coastal city Karachi and a non-coastal city Jacobabad, K and J is used as a subscripts for parameters of Karachi and Jacobabad respectively. All variables used here are dependent on the location (latitude and longitude) of our stations except G. To employ ARIMA modeling, the first eighteen years data is used for modeling and forecast is done for the last five years data. In most cases results show good correlation among monthly actual and monthly forecasted values of all the predictors. Next, multiple linear regression is employed to the data obtained by ARIMA modeling and models for mean monthly observed G values are constructed. For each station, two equations are constructed, the R values are above 93% for each model, showing adequacy of the fit. Our computations show that solar cell efficiency can be increased if better modeling for meteorological predictors governs the process. (author)

  20. Review of the CdCl2 Treatment Used in CdS/CdTe Thin Film Solar Cell Development and New Evidence towards Improved Understanding

    OpenAIRE

    Dharmadasa, I. M.

    2014-01-01

    Cadmium chloride treatment is a key processing step identified in the late 1970s to drastically improve the solar to electric conversion efficiency of CdS/CdTe thin film solar cells. Although a large body of experimental results are available to date, this process is yet to be understood even after three decades of research. This paper reviews the experimental results available, presents some new clues leading to improved understanding and suggests key research areas necessary to fully unders...

  1. Cadmium Toxicity on Arterioles Vascular Smooth Muscle Cells of Spontaneously Hypertensive Rats

    Directory of Open Access Journals (Sweden)

    Elbert L. Myles

    2006-12-01

    Full Text Available Cadmium (Cd is frequently used in various industrial applications and is a ubiquitous environmental toxicant, also present in tobacco smoke. An important route of exposure is the circulatory system whereas blood vessels are considered to be main stream organs of Cd toxicity. Our previous results indicate that cadmium chloride (CdCl2 affects mean arterial blood pressure in hypertensive rats. We hypothesized that Cd alters the intracellular calcium transient mechanism, by cadmium-induced stimulation of MAPKs (ERK 1 & 2 which is mediated partially through calcium-dependent PKC mechanism. To investigate this hypothesis, we exposed primary cultures of vascular smooth muscle cells (VSMCs from wistar kyoto (WKY and spontaneously hypertensive rats (SHR to increased concentrations of CdCl2 on cell viability, expression of mitogen-activated protein kinases (MAPKs/ERK 1 & 2, and protein kinase C (PKC which are activated by Cd in several cell types. The results from these studies indicate that CdCl2 decreased cell viability of both SHR and WKY VSMCs in a concentration dependent-manner. Viability of both cell types decreased 33±5.3 (SHR and 39±2.3% (WKY when exposed to 1 μM CdCl2, whereas, 8 and 16 μM reduced viability by 66±3.1 and 62±4.5% in SHR cells. CdCl2 increased ERK 1 & 2 in a biphasic manner with maximum increase occurring when cells are exposed to 1 and 4 μM in SHR VSMCs, whereas, a reduction in ERK 1 and 2 is observed when WKY cells are treated with 2 μM. The results also indicate that CdCl2 increased PKC a/ß in both SHR and WKY VSMCs with a greater increase in expression in SHR VSMCs. In addition, the [Ca2+]i chelator, BAPTA, suppressed the CdCl2 effect, whereas, the PKC inhibitor, GF109203X, reduced the CdCl2 induced-effect on PKC expression. The present studies support the hypothesis that Cd can be a risk factor of hypertension through dysfunction of vascular smooth muscle cells

  2. Response of quiescent and total tumor cells in solid tumors to neutrons with various cadmium ratios

    International Nuclear Information System (INIS)

    Purpose: Response of quiescent (Q) and total tumor cells in solid tumors to neutron irradiation with three different cadmium (Cd) ratios was examined. The role of Q cells in tumor control was also discussed. Methods and Materials: C3H/He mice bearing SCC VII tumors received continuous administration of 5-bromo-2'-deoxyuridine (BrdU) for 5 days using implanted mini-osmotic pumps to label all proliferating (P) cells. Thirty minutes after intraperitoneal injection of sodium borocaptate-10B (BSH), or 3 h after oral administration of dl-p-boronophenylalanine-10B (BPA), the tumors were irradiated with neutrons, or those without 10B-compounds were irradiated with gamma rays. This neutron irradiation was performed using neutrons with three different cadmium (Cd) ratios. The tumors were then excised, minced, and trypsinized. The tumor cell suspensions were incubated with cytochalasin-B (a cytokinesis-blocker), and the micronucleus (MN) frequency in cells without BrdU labeling (Q cells) was determined using immunofluorescence staining for BrdU. The MN frequency in total (P + Q) tumor cells was determined from tumors that were not pretreated with BrdU. The sensitivity to neutrons was evaluated in terms of the frequency of induced micronuclei in binuclear tumor cells (MN frequency). Results: Without 10B-compounds, the MN frequency in Q cells was lower than that in the total cell population. The sensitivity difference between total and Q cells was reduced by neutron irradiation. Relative biological effectiveness (RBE) of neutrons compared with gamma rays was larger in Q cells than in total cells, and the RBE values for low-Cd-ratio neutrons tended to be larger than those for high-Cd-ratio neutrons. With 10B-compounds, MN frequency for each cell population was increased, especially for total cells. This increase in MN frequency was marked when high-Cd-ratio neutrons were used. BPA increased the MN frequency for total tumor cells more than BSH. Nevertheless, the sensitivity of Q

  3. Stimulation by cadmium of myohemerythrin-like cells in the gut of the annelid Nereis diversicolor.

    Science.gov (United States)

    Demuynck, Sylvain; Bocquet-Muchembled, Beatrice; Deloffre, Laurence; Grumiaux, Fabien; Leprêtre, Alain

    2004-03-01

    Isolated guts of Nereis diversicolor revealed the existence of a cadmium-binding protein, the MPII, belonging to the group of hemerythrins and myohemerythrins. The presence of MPII in the cells of the intestine was demonstrated by immunocytochemistry, using anti-MPII, a monoclonal antibody. In addition, using in situ hybridization and northern blotting, it was shown that MPII-cells are the site of synthesis of this molecule. Exposure of the worms to cadmium led to the cellular activation process of MPII-cells (i.e. transformation of the nucleolus, development of the endoplasmic reticulum and the Golgi apparatus), although MPII mRNA transcript levels were unchanged. Enzyme-linked immunosorbent assay (ELISA) of gut extracts revealed that MPII levels were increased after exposure to Cd, so it appears that this protein is synthesized as a response to Cd exposure without any new synthesis of mRNA. This mechanism of regulation is quite similar to that reported in the case of mammalian ferritin and may be involved in the regulation of Cd levels in this worm. PMID:14978053

  4. Nanocrystalline silicon based thin film solar cells

    Science.gov (United States)

    Ray, Swati

    2012-06-01

    Amorphous silicon solar cells and panels on glass and flexible substrate are commercially available. Since last few years nanocrystalline silicon thin film has attracted remarkable attention due to its stability under light and ability to absorb longer wavelength portion of solar spectrum. For amorphous silicon/ nanocrystalline silicon double junction solar cell 14.7% efficiency has been achieved in small area and 13.5% for large area modules internationally. The device quality nanocrystalline silicon films have been fabricated by RF and VHF PECVD methods at IACS. Detailed characterizations of the materials have been done. Nanocrystalline films with low defect density and high stability have been developed and used as absorber layer of solar cells.

  5. Porous Silicon for Light Management in Silicon Solar Cells

    OpenAIRE

    2011-01-01

    In the present work possibilities of utilizing porous silicon (PS) to enhance absorption in silicon solar cells are investigated. Silicon solar cells produce energy by converting the incoming solar radiation to electricity and the efficiency of this technology will naturally depend on the amount of light that can be absorbed by the solar cell. Antireflection coatings are used on the surface of solar cells to increase the fraction of light that enters the cell. In addition texture and rear sid...

  6. Solar Simulation for the NTNU Test Satellite Solar Cells

    OpenAIRE

    Nygren, Martin Alexander

    2014-01-01

    The relevant energy theory behind intensity and spectral irradiance from the sun is discussed with regard to how it changes due to factors like Earth-Sun distance, solid angle of the sun disk and circumsolar region, angle of incidence and atmospheric mass. This translates to how the experienced conditions for solar cells vary, how and why solar simulation is done the way it is with such stringent requirements, as well as what can be expected in terms of difference between controlled, fixed co...

  7. Cadmium affects viability of bone marrow mesenchymal stem cells through membrane impairment, intracellular calcium elevation and DNA breakage

    Directory of Open Access Journals (Sweden)

    Abnosi Mohammad Hussein

    2010-01-01

    Full Text Available Background: Cadmium is an important heavy metal with occupational and environmental hazard. Cadmium toxicity results mainly in bone-related complication such as itai-itai disease. Mesenchymal stem cells of the bone marrow have the ability to differentiate to osteoblasts which ensure the well-being of the bone tissue. Thus the aim was to investigate the effect of cadmium on viability of rat bone marrow mesenchymal stem cells. Materials and Methods: The rat bone marrow mesenchymal stem cells were grown to confluency in DMEM medium supplemented with 15% fetal bovine serum and penicillin-streptomycin up to third passage. Then the cells were treated with 0, 5, 15, 25, 35, and 45 of CdCl 2 at 12, 24, 36, and 48 h, and their viability was investigated using trypan blue staining. In addition, after treatment with selected dose (15 and 45 μM and time (24 and 48 h the cell morphology, DNA damage and calcium content of the cells were evaluated. Data was analyzed using one and two-way ANOVA (Tukey test and the P2+ was observed. Conclusion: Cadmium chloride is a toxic compound which might affect the well-being of bone tissue through affecting the mesenchymal stem cells.

  8. Thermal influence on charge carrier transport in solar cells based on GaAs PN junctions

    Energy Technology Data Exchange (ETDEWEB)

    Osses-Márquez, Juan; Calderón-Muñoz, Williams R., E-mail: wicalder@ing.uchile.cl [Department of Mechanical Engineering, University of Chile, Beauchef 850, Santiago (Chile)

    2014-10-21

    The electron and hole one-dimensional transport in a solar cell based on a Gallium Arsenide (GaAs) PN junction and its dependency with electron and lattice temperatures are studied here. Electrons and heat transport are treated on an equal footing, and a cell operating at high temperatures using concentrators is considered. The equations of a two-temperature hydrodynamic model are written in terms of asymptotic expansions for the dependent variables with the electron Reynolds number as a perturbation parameter. The dependency of the electron and hole densities through the junction with the temperature is analyzed solving the steady-state model at low Reynolds numbers. Lattice temperature distribution throughout the device is obtained considering the change of kinetic energy of electrons due to interactions with the lattice and heat absorbed from sunlight. In terms of performance, higher values of power output are obtained with low lattice temperature and hot energy carriers. This modeling contributes to improve the design of heat exchange devices and thermal management strategies in photovoltaic technologies.

  9. Thermal influence on charge carrier transport in solar cells based on GaAs PN junctions

    International Nuclear Information System (INIS)

    The electron and hole one-dimensional transport in a solar cell based on a Gallium Arsenide (GaAs) PN junction and its dependency with electron and lattice temperatures are studied here. Electrons and heat transport are treated on an equal footing, and a cell operating at high temperatures using concentrators is considered. The equations of a two-temperature hydrodynamic model are written in terms of asymptotic expansions for the dependent variables with the electron Reynolds number as a perturbation parameter. The dependency of the electron and hole densities through the junction with the temperature is analyzed solving the steady-state model at low Reynolds numbers. Lattice temperature distribution throughout the device is obtained considering the change of kinetic energy of electrons due to interactions with the lattice and heat absorbed from sunlight. In terms of performance, higher values of power output are obtained with low lattice temperature and hot energy carriers. This modeling contributes to improve the design of heat exchange devices and thermal management strategies in photovoltaic technologies.

  10. 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.

  11. Progress in Thin Film Solar Cells Based on Cu2ZnSnS4

    OpenAIRE

    Hongxia Wang

    2011-01-01

    The research in thin film solar cells has been dominated by light absorber materials based on CdTe and Cu(In,Ga)Se2 (CIGS) in the last several decades. The concerns of environment impact of cadmium and the limited availability of indium in those materials have driven the research towards developing new substitute light absorbers made from earth abundant, environment benign materials. Cu2ZnSnS4 (CZTS) semiconductor material has emerged as one of the most promising candidates for this aim and h...

  12. Investigation of solar cell radiation damage

    International Nuclear Information System (INIS)

    Development of communications satellites has led to the requirement for a greater and longer lived solar cell power source. Accordingly, studies have been undertaken with the aim of determining which solar cell array provides the greatest power at end of life and the amount of degradation. Investigation of the damage done to thin silicon and thin film CdS solar cells is being carried out in two steps. First, irradiations were performed singly with 0.15, 1.0 and 2.0MeV electrons and 0.7, 2.5 and 22MeV proton. Solar cells and their cover materials were irradiated separately in order to locate the sites of the damage. Diffusion length and I.V. characteristics of the cells and transmission properties of the cover materials were measured. All neasurements were made in vacuum immediately after irradiation. In the second part it is intended to study the effect of various combinations of proton, electron and photon irradiation both with and without an electrical load. The results of this part show whether synergism is involved in solar cell damage and the relative importance of each of three radiation sources if synergism is found

  13. Effect of Storage on Performance of Super Nickel-Cadmium Cells

    Science.gov (United States)

    Vaidyanathan, Hari; Rao, Gopalakrishna M.

    1997-01-01

    A study was undertaken to examine the capacity maintenance features of SUPER nickel-cadmium cells when stored for extended periods to determine whether the features change when the same kinds of positive plates as that used in nickel-hydrogen cells are used, The cells maintained their capacity when stored at 0 C in the discharged state and at 0 C in the charged state by continuously trickle charging. There was a capacity loss when stored in the open-circuit condition at 28 C. A cycling test at 17% depth of discharge for 2400 cycles using cells stored at various conditions showed that cells maintained good end of discharge voltage regardless of their storage history. However, the EOD voltages of stored cells were lower by 10 mV compared to those of fresh cells. The capacity at the end of the cycling test decreased for the stored cells by 2-7 Ah. The storage related capacity loss is lower for SUPER Ni-Cd cells compared to that of Ni-H2 cells containing a hydrogen precharge. The results suggest the pivotal role of hydrogen pressure in the capacity loss phenomenon.

  14. 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

  15. 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.

  16. Influence of radiation on the properties of solar cells

    OpenAIRE

    Zdravković Miloš R.; Vasić Aleksandra I.; Radosavljević Radovan Lj.; Vujisić Miloš Lj.; Osmokrović Predrag V.

    2011-01-01

    The wide substitution of conventional types of energy by solar energy lies in the rate of developing solar cell technology. Silicon is still the mostly used element for solar cell production, so efforts are directed to the improvement of physical properties of silicon structures. There are several trends in the development of solar cells, but mainly two directions are indicated: the improvement of the conventional solar cell characteristics based on semiconductor materials, and explorin...

  17. 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...

  18. CZTSSe thin film solar cells: Surface treatments

    Science.gov (United States)

    Joglekar, Chinmay Sunil

    Chalcopyrite semiconducting materials, specifically CZTS, are a promising alternative to traditional silicon solar cell technology. Because of the high absorption coefficient; films of the order of 1 micrometer thickness are sufficient for the fabrication of solar cells. Liquid based synthesis methods are advantageous because they are easily scalable using the roll to roll manufacturing techniques. Various treatments are explored in this study to enhance the performance of the selenized CZTS film based solar cells. Thiourea can be used as a sulfur source and can be used to tune band gap of CZTSSe. Bromine etching can be used to manipulate the thickness of sintered CZTSSe film. The etching treatment creates recombination centers which lead to poor device performance. Various after treatments were used to improve the performance of the devices. It was observed that the performance of the solar cell devices could not be improved by any of the after treatment steps. Other surface treatment processes are explored including KCN etching and gaseous H2S treatments. Hybrid solar cells which included use of CIGS nanoparticles at the interface between CZTSSe and CdS are also explored.

  19. 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%.

  20. Solar cell and its manufacturing process

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Hisashi; Komatsu, Yasumitsu.

    1989-01-20

    The solar cell with a structure of the Cds sintered film/CdTe sintered film is excellent at mass productivity because of usage of screen printing, but its conversion efficiency is insufficient in comparison with that of the single crystal silicon solar cell. Since the CdS/CdTe solar cell is a heterojunction solar cell, it is necessary that lattice constants of two materials are close each other in order to improve its performance. However, the mismatching of the lattices of CdS and CdTe is as fairly big as 11%. In order to ameliorate this mismatching, this invention substitutes the CdTe sintered film with the CdS-CdTe mixed crystal sintered film. Besides, the CdS-CdTe mixed crystal phase has its narrow forbidden bandwidth at or below 50 mol % of its CdS content, hence with it, a solar cell can be obtained which is highly sensitive to the light of long wave lengths. 2 tabs.

  1. Antimony selenide thin-film solar cells

    Science.gov (United States)

    Zeng, Kai; Xue, Ding-Jiang; Tang, Jiang

    2016-06-01

    Due to their promising applications in low-cost, flexible and high-efficiency photovoltaics, there has been a booming exploration of thin-film solar cells using new absorber materials such as Sb2Se3, SnS, FeS2, CuSbS2 and CuSbSe2. Among them, Sb2Se3-based solar cells are a viable prospect because of their suitable band gap, high absorption coefficient, excellent electronic properties, non-toxicity, low cost, earth-abundant constituents, and intrinsically benign grain boundaries, if suitably oriented. This review surveys the recent development of Sb2Se3-based solar cells with special emphasis on the material and optoelectronic properties of Sb2Se3, the solution-based and vacuum-based fabrication process and the recent progress of Sb2Se3-sensitized and Sb2Se3 thin-film solar cells. A brief overview further addresses some of the future challenges to achieve low-cost, environmentally-friendly and high-efficiency Sb2Se3 solar cells.

  2. 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.

  3. Light-trapping in perovskite solar cells

    Science.gov (United States)

    Du, Qing Guo; Shen, Guansheng; John, Sajeev

    2016-06-01

    We numerically demonstrate enhanced light harvesting efficiency in both CH3NH3PbI3 and CH(NH2)2PbI3-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(NH2)2PbI3 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(NH2)2PbI3 based photonic crystal solar cell is 23.4%, well above the current world record efficiency of 20.1%.

  4. Cadmium uptake and sequestration kinetics in individual leaf cell protoplasts of the Cd/Zn hyperaccumulator Thlaspi caerulescens.

    Science.gov (United States)

    Leitenmaier, Barbara; Küpper, Hendrik

    2011-02-01

    Hyperaccumulators store accumulated metals in the vacuoles of large leaf epidermal cells (storage cells). For investigating cadmium uptake, we incubated protoplasts obtained from leaves of Thlaspi caerulescens (Ganges ecotype) with a Cd-specific fluorescent dye. A fluorescence kinetic microscope was used for selectively measuring Cd-uptake and photosynthesis in different cell types, so that physical separation of cell types was not necessary. Few minutes after its addition, cadmium accumulated in the cytoplasm before its transport into the vacuole. This demonstrated that vacuolar sequestration is the rate-limiting step in cadmium uptake into protoplasts of all leaf cell types. During accumulation in the cytoplasm, Cd-rich vesicle-like structures were observed. Cd uptake rates into epidermal storage cells were higher than into standard-sized epidermal cells and mesophyll cells. This shows that the preferential heavy metal accumulation in epidermal storage cells, previously observed for several metals in intact leaves of various hyperaccumulator species, is due to differences in active metal transport and not differences in passive mechanisms like transpiration stream transport or cell wall adhesion. Combining this with previous studies, it seems likely that the transport steps over the plasma and tonoplast membranes of leaf epidermal storage cells are driving forces behind the hyperaccumulation phenotype. PMID:20880204

  5. 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 gener

  6. The CRRES high efficiency solar panel

    International Nuclear Information System (INIS)

    This paper reports on the High Efficiency Solar Panel (HESP) experiments which is to provide both engineering and scientific information concerning the effects of space radiation on advanced gallium arsenide (GaAs) solar cells. The HESP experiment consists of an ambient panel, and annealing panel and a programmable load. This experiment, in conjunction with the radiation measurement experiments abroad the CREES, provides the first opportunity to simultaneously measure the trapped radiation belts and the results of radiation damage to solar cells. The engineering information will result in a design guide for selecting the optimum solar array characteristics for different orbits and different lifetimes. The scientific information will provide both correlation of laboratory damage effects to space damage effects and a better model for predicting effective solar cell panel lifetimes

  7. 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. PMID:26698787

  8. Review of the CdCl2 Treatment Used in CdS/CdTe Thin Film Solar Cell Development and New Evidence towards Improved Understanding

    Directory of Open Access Journals (Sweden)

    I. M. Dharmadasa

    2014-04-01

    Full Text Available Cadmium chloride treatment is a key processing step identified in the late 1970s to drastically improve the solar to electric conversion efficiency of CdS/CdTe thin film solar cells. Although a large body of experimental results are available to date, this process is yet to be understood even after three decades of research. This paper reviews the experimental results available, presents some new clues leading to improved understanding and suggests key research areas necessary to fully understand this crucial processing step. Improved understanding will lead to further increase in conversion efficiency of CdS/CdTe solar cells well beyond 20%.

  9. 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.

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

    International Nuclear Information System (INIS)

    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/cm2, we have been able to achieve a power conversion efficiency (PCE) of 3.1 % with fill factor 0.42 for our typical solar cell

  11. Chapter 10: CPV Multijunction Solar Cell Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Osterwald, Carl R.; Siefer, Gerald

    2016-04-15

    Characterization of solar cells can be divided into two types: the first is measurement of electrooptical semiconductor device parameters, and the second is determination of electrical conversion efficiency. This chapter reviews the multijunction concepts that are necessary for understanding Concentrator photovoltaic (CPV) cell characterization techniques, and describes how CPV efficiency is defined and used. For any I-V measurement of a multijunction cell, the sun simulator spectrum has to be adjusted in a way that all junctions generate the same photocurrent ratios with respect to each other as under reference conditions. The chapter discusses several procedures for spectral irradiance adjustments of solar simulators, essential for multijunction measurements. It overviews the light sources and optics commonly used in simulators for CPV cells under concentration. Finally, the chapter talks about the cell area, quantum efficiency (QE), and current-voltage (I-V) curve measurements that are needed to characterize cells as a function of irradiance.

  12. High-slope photoconductive cells based on screen-printed and sintered cadmium sulfide; the long-term stability properties

    Czech Academy of Sciences Publication Activity Database

    Franc, Jiří; Nešpůrek, Stanislav

    2007-01-01

    Roč. 9, č. 7 (2007), s. 2205-2210. ISSN 1454-4164 Institutional research plan: CEZ:AV0Z40400503; CEZ:AV0Z40500505 Keywords : photoconductive cell * cadmium sulfide * sintering Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.827, year: 2007

  13. Nanophotonic front electrodes for perovskite solar cells

    Science.gov (United States)

    Paetzold, Ulrich Wilhelm; Qiu, Weiming; Finger, Friedhelm; Poortmans, Jef; Cheyns, David

    2015-04-01

    In less than 3 years' time, a vast progress in power conversion efficiencies of organometal halide perovskite solar cells has been achieved by optimization of the device architecture, charge transport layers, and interfaces. A further increase in these efficiencies is expected from an improvement in the optical properties via anti-reflection coatings and nanophotonic light management concepts. In this contribution, we report on the development and implementation of a nanophotonic front electrode for perovskite solar cells. The nanostructures were replicated via the versatile and large-area compatible UV-nanoimprint lithography. The shallow design of the used transparent and conductive nanostructures enabled easy integration into our solution-based baseline process. Prototype methylammonium lead iodide perovskite solar cells show an improvement of 5% in short-circuit current density and an improvement from 9.6% to 9.9% in power conversion efficiency compared to the flat reference device.

  14. Hybrid solar cell on a carbon fiber.

    Science.gov (United States)

    Grynko, Dmytro A; Fedoryak, Alexander N; Smertenko, Petro S; Dimitriev, Oleg P; Ogurtsov, Nikolay A; Pud, Alexander A

    2016-12-01

    In this work, a method to assemble nanoscale hybrid solar cells in the form of a brush of radially oriented CdS nanowire crystals around a single carbon fiber is demonstrated for the first time. A solar cell was assembled on a carbon fiber with a diameter of ~5-10 μm which served as a core electrode; inorganic CdS nanowire crystals and organic dye or polymer layers were successively deposited on the carbon fiber as active components resulting in a core-shell photovoltaic structure. Polymer, dye-sensitized, and inverted solar cells have been prepared and compared with their analogues made on the flat indium-tin oxide electrode. PMID:27216603

  15. 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.

  16. Thin-film solar cells. Duennschichtsolarzellen

    Energy Technology Data Exchange (ETDEWEB)

    Bloss, W.H.; Pfisterer, F.; Schock, H.W. (Stuttgart Univ. (Germany, F.R.). Inst. fuer Physikalische Elektronik)

    1990-01-01

    The authors present the state of the art in research and development, technology, production and marketing, and of the prospects of thin-film solar cells. Thin-film solar cells most used at present are based on amorphous silicon and on the compound semiconductors CuInSe{sub 2} and CdTe. Efficiencies in excess 12% have been achieved (14.1% with CuInSe{sub 2}). Stability is the main problem with amorphous silicon. Thin-film solar cells made from compound semiconductors do not have this problem, though their cost-effective series production needs to be shown still. The development potential of the three types mentioned will be ca. 30% in terms of efficiency: in terms of production cost, it is estimated with some certainty to be able to reach the baseline of 1 DM/Watt peak output (W{sub p}). (orig.).

  17. A special issue on solar cells

    Institute of Scientific and Technical Information of China (English)

    Yi-Bing CHENG

    2011-01-01

    @@ The increasing demand for renewable energy has made the solar cell technology as one of the most significantresearch and development areas of today.Silicon based solar cells are the dominant photovoltaic products at the present time, but the relatively high costs are barriers for their broad applications.Research has been active worldwide in developing other photovoltaic technologies that use cheap materials and can be easily manufactured.Organic solar cells have attracted a lot of interests recently due to their potential to be low cost photovoltaic technologies.This special issue of the Frontiers of Optoelectronics in China has collected research articles by a number of Chinese and international experts.It is aimed to broaden the readers' view about some of the recent developments and challenges in this important R&D field.Thirteen excellent papers are in this special issue including 4 review articles and 9 research articles.

  18. Recent progress on microcrystalline solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Shah, A.; Meier, J.; Torres, P.; Kroll, U.; Fischer, D.; Beck, N.; Wyrsch, N.; Keppner, H. [Univ. of Neuchatel (Switzerland). Inst. of Microtechnology

    1997-12-31

    The most important features of microcrystalline silicon ({micro}c-Si:H) and microcrystalline silicon based p-i-n solar cells (specially those deposited by VHF-Glow Discharge) are reviewed. Since such material has been recognized to be a photovoltaically active material, stabilized cell efficiencies have steadily risen and have now reached 12% in the so called micromorph (microcrystalline/amorphous) tandem cell configuration.

  19. Embryotoxicity hazard assessment of cadmium and arsenic compounds using embryonic stem cells

    International Nuclear Information System (INIS)

    The Embryonic Stem Cell Test (EST) has been successfully validated as an in vitro method for detecting embryotoxicity, showing a good overall test accuracy of 78% [Genschow, E., Spielmann, H., Scholz, G., Seiler, A., Brown, N., Piersma, A., Brady, M., Clemann, N., Huuskonen, H., Paillard, F., Bremer, S., Becker, K., 2002. The ECVAM international validation study on in vitro embryotoxicity tests: results of the definitive phase and evaluation of prediction models. European Centre for the Validation of Alternative Methods. Altern. Lab. Anim. 30, 151-176]. Methylmercury was the only strong in vivo embryotoxicant falsely predicted as non-embryotoxic making the metal the most significant outlayer [Genschow, E., Spielmann, H., Scholz, G., Pohl, I., Seiler, A., Clemann, N., Bremer, S., Becker, K., 2004. Validation of the Embryonic Stem Cell Test in the international ECVAM validation study on three in vitro embryotoxicity tests. Altern. Lab. Anim. 32, 209-244]. The misclassification of methylmercury and the potential environmental exposure to developmental toxic heavy metals promoted our investigation of whether the EST applicability domain covers cadmium and arsenic compounds. The EST misclassified cadmium, arsenite and arsenate compounds as non-embryotoxic, even when including arsenic metabolites (methylarsonate, methylarsonous and dimethylarsinic). The reasons were the lack of higher cytotoxicity towards embryonic stem cells as compared to more mature cells (3T3 fibroblasts) or the absence of inhibition of cardiac differentiation by specific mechanisms rather than general cytotoxicity. Including EST data on heavy metals from the literature (lithium, methylmercury, trivalent chromium and hexavalent chromium) revealed that the test correctly predicted the embryotoxic potential of three out of the seven heavy metals, indicating an insufficient predictivity for such metals. Refinement of the EST prediction model and inclusion of additional toxicological endpoints could

  20. Solar cells from wastes of integrated circuits

    Energy Technology Data Exchange (ETDEWEB)

    Knev, S.; Lakova, M.; Stoyanov, V.; Vlayev, Kh.

    1981-01-01

    Results are presented from using a defective silicon plates for making solar cells with reduces cost and satisfactory characteristics. These monocrystal plates were exposed to high-temperature processes for the formation of crystals of integrated circuits and subsequent mechanical and chemical procedures for removal of the diffusion transitions and to thin the plates. All of this could promote the manifestation of dislocations, fractures and as a result deteriorate the parameters of the current carriers in the initial plates, making them unsuitable for purposes of photoelectrical transformation of solar light. Data are presented which indicate the successful use of wastes for the fabrication of solar cells. Experiments were conducted on plates 50 X 76mm, structures of type n/sup +/-p, n/sup +/-p-p/sup +/, p/sup +/-n, p/sup +/-n-n/sup +/ were made. Studies were made of their main characteristics and it is indicated that the formed transitions have qualities suitable for creating solar cells with good parameters comparable to the solar cells made on the basis of new plates. This was illustrated by samples with efficiency to 15% under conditions of AM2. Decrease in the cost is due to the reduction in technological operation.

  1. Advances in thin-film solar cells for lightweight space photovoltaic power

    Science.gov (United States)

    Landis, Geoffrey A.; Bailey, Sheila G.; Flood, Dennis J.

    1989-01-01

    The present stature and current research directions of photovoltaic arrays as primary power systems for space are reviewed. There have recently been great advances in the technology of thin-film solar cells for terrestrial applications. In a thin-film solar cell the thickness of the active element is only a few microns; transfer of this technology to space arrays could result in ultralow-weight solar arrays with potentially large gains in specific power. Recent advances in thin-film solar cells are reviewed, including polycrystalline copper-indium selenide (CuInSe2) and related I-III-VI2 compounds, polycrystalline cadmium telluride and related II-VI compounds, and amorphous silicon:hydrogen and alloys. The best experimental efficiency on thin-film solar cells to date is 12 percent AMO for CuIn Se2. This efficiency is likely to be increased in the next few years. The radiation tolerance of thin-film materials is far greater than that of single-crystal materials. CuIn Se2 shows no degradation when exposed to 1 MeV electrons. Experimental evidence also suggests that most of all of the radiation damage on thin-films can be removed by a low temperature anneal. The possibility of thin-film multibandgap cascade solar cells is discussed, including the tradeoffs between monolithic and mechanically stacked cells. The best current efficiency for a cascade is 12.5 percent AMO for an amorphous silicon on CuInSe2 multibandgap combination. Higher efficiencies are expected in the future. For several missions, including solar-electric propulsion, a manned Mars mission, and lunar exploration and manufacturing, thin-film photovolatic arrays may be a mission-enabling technology.

  2. Arsenic, cadmium, mercury and nickel stimulate cell growth via NADPH oxidase activation.

    Science.gov (United States)

    Mohammadi-Bardbori, Afshin; Rannug, Agneta

    2014-11-10

    Exposure to metals and metalloids including arsenic, cadmium, mercury, and nickel has been a worldwide health problem for several decades. The aim of this study was to learn how metal-induced oxidative stress triggers cell proliferation, a process of great significance for cancer. NADPH oxidase (NOX) activity and cell proliferation were measured as endpoints in both NOX-deficient and NOX-proficient cells. The X chromosome linked CGD (X-CGD) human promyelocytic leukemia PLB-985 cells lacking gp91phox and the X-CGD cells re-transfected with gp91phox (X-CGD-gp91(phox)) were used together with immortalized human keratinocyte cells (HaCaT). The cells were exposed to different concentrations of the metals alone or together with the NOX inhibitor, diphenyleneiodonium (DPI). We found that the studied metals increased NOX activity. They stimulated cell proliferation in HaCaT and X-CGD-gp91(phox) cells at concentrations below 1μM but not in the X-CGD cells that lack functional NOX. Addition of DPI attenuated the metal-induced cell proliferation. At concentrations above 1μM these metals inhibited cell proliferation. Based on these findings, we propose that many environmental pollutants, including metals and also endogenous NOX-activators such as oxidants and growth factors, interfere with cell growth kinetics by increasing the levels of the diffusible molecule H2O2. Here, we provide evidence that NOXs is central to the mechanism of metal-mediated reactive oxygen species production and stimulation of cell proliferation. PMID:25446860

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

    DEFF Research Database (Denmark)

    Akhmatov, Vladislav; Galster, Georg; Larsen, Esben

    1998-01-01

    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......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...

  4. Photovoltage analysis of a heterojunction solar cell

    Institute of Scientific and Technical Information of China (English)

    Xiong Chao; Yao Ruo-He; Geng Kui-Wei

    2011-01-01

    According to the p-n junction model of Shockley, the relationship between the equilibrium carrier concentrations of n-type and p-type semiconductors on the edges of the depletion region of a p-n junction solar cell is analysed. The calculation results show that the photovoltage can exceed the built-in voltage for a special kind of heterojunction solar cell. When the photovoltage exceeds the built-in voltage under illumination, the dark current and the photocurrent are impeded by the peak of voltage barrier at the interface and the expression of the total Ⅰ-Ⅴ characteristic is given.

  5. High performance polymer tandem solar cell

    Science.gov (United States)

    da Silva, Wilson Jose; Schneider, Fabio Kurt; Mohd Yusoff, Abd. Rashid Bin; Jang, Jin

    2015-12-01

    A power conversion efficiency of 9.02% is obtained for a fully solution-processed polymer tandem solar cell, based on the diketopyrrolopyrrole unit polymer as a low bandgap photoactive material in the rear subcell, in conjunction with a new robust interconnecting layer. This interconnecting layer is optically transparent, electrically conductive, and physically strong, thus, the charges can be collected and recombined in the interconnecting layer under illumination, while the charge is generated and extracted under dark conditions. This indicates that careful interface engineering of the charge-carrier transport layer is a useful approach to further improve the performance of polymer tandem solar cells.

  6. 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...

  7. Stability Issues on Perovskite Solar Cells

    OpenAIRE

    Xing Zhao; Nam-Gyu Park

    2015-01-01

    Organo lead halide perovskite materials like methylammonium lead iodide (CH3NH3PbI3) and formamidinium lead iodide (HC(NH2)2PbI3) 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 natu...

  8. Si microwire-array solar cells

    OpenAIRE

    Putnam, Morgan C.; Boettcher, Shannon W.; Kelzenberg, Michael D.; Turner-Evans, Daniel B.; Spurgeon, Joshua M.; Warren, Emily L.; Briggs, Ryan M.; Lewis, Nathan S.; Atwater, Harry A.

    2010-01-01

    Si microwire-array solar cells with Air Mass 1.5 Global conversion efficiencies of up to 7.9% have been fabricated using an active volume of Si equivalent to a 4 μm thick Si wafer. These solar cells exhibited open-circuit voltages of 500 mV, short-circuit current densities (J_(sc)) of up to 24 mA cm^(-2), and fill factors >65% and employed Al_2O_3 dielectric particles that scattered light incident in the space between the wires, a Ag back reflector that prevented the escape of incident illumi...

  9. 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.

  10. DNA damage in haemocytes and midgut gland cells of Steatoda grossa (Theridiidae) spiders exposed to food contaminated with cadmium.

    Science.gov (United States)

    Stalmach, Monika; Wilczek, Grażyna; Wilczek, Piotr; Skowronek, Magdalena; Mędrzak, Monika

    2015-03-01

    The aim of this study was to assess the genotoxic effects of Cd on haemocytes and midgut gland cells of web-building spiders, Steatoda grossa (Theridiidae), exposed to the metal under laboratory conditions. Analyzes were conducted on adult females and males, fed for four weeks with cadmium-contaminated Drosophila hydei flies, grown on a medium suplemented with 0.25 mM CdCl2. The comet assay, providing a quantitative measure of DNA strand breaks, was used to evaluate the DNA damage caused by the metal. Cadmium content was measured in whole spider bodies by the AAS method. Metal body burden was significantly lower in females (0.25 µgg(-1) dry weight) than in males (3.03 µgg(-1) dry weight), suggesting that females may have more effective mechanisms controlling the uptake of metal, via the digestive tract, or its elimination from the body. Irrespectively of sex, spiders fed prey contaminated with cadmium showed significantly higher values of comet parameters: tail DNA (TDNA), tail length (TL) and olive tail moment (OTM), in comparison with the control. In midgut gland cells, the level of DNA damage was higher for males than females, while in haemocytes the genotoxic effect of cadmium was greater in females. The obtained results indicate that in spiders cadmium displays strong genotoxic effects and may cause DNA damage even at low concentrations, however the severity of damage seems to be sex- and internal organ-dependent. The comet assay can be considered a sensitive tool for measuring the deleterious effect of cadmium on DNA integrity in spiders. PMID:25531832

  11. 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...

  12. Cadmium induces apoptosis in anterior pituitary cells that can be reversed by treatment with antioxidants

    International Nuclear Information System (INIS)

    Cadmium (Cd2+) is an ubiquitous toxic metal that is involved in a variety of pathological conditions. Several reports indicate that Cd2+ alters normal pituitary hormone secretion; however, little is known about the mechanisms that induce this misregulation. This paper reports the effect of Cd2+ on anterior pituitary cell viability and its relation to prolactin secretion. Cd2+ concentrations above 10 μM were found to be cytotoxic for pituitary cells. Morphological studies as well as DNA ladder fragmentation and caspase activation showed that Cd2+-treated cells undergo apoptosis. Even though several hours were needed to detect Cd2+-induced cytotoxicity, the effect of the metal became irreversible very quickly, requiring only 3 h of treatment. Prolactin release (measured at 48 h) was inhibited when the cells were exposed to Cd2+ for 1 h, before any change in cell viability was observed. The antioxidants N-acetyl-cysteine and Trolox (a hydrosoluble derivative of vitamin E), but not ascorbic acid, reversed both Cd2+-mediated cytotoxicity and the inhibition of prolactin release, supporting the involvement of oxidative stress in the mechanism of Cd2+ action. In summary, the present work demonstrates that Cd2+ is cytotoxic for anterior pituitary cells, that this effect is due to an induction of apoptosis, and that it can be reversed by antioxidants

  13. Polymer-fullerene bulk heterojunction solar cells

    International Nuclear Information System (INIS)

    Organic solar cells have the potential to be low-cost and efficient solar energy converters, with a promising energy balance. They are made of 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 solar cells, their state-of-the-art performance and limitations, as well as novel concepts to achieve a better material stability and higher power conversion efficiencies. We will also briefly review processing and cost in view of the market potential.

  14. Ultra-thin GaAs single-junction solar cells integrated with a reflective back scattering layer

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Weiquan; Becker, Jacob; Liu, Shi; Kuo, Ying-Shen; Li, Jing-Jing; Zhang, Yong-Hang [Center for Photonics Innovation and School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287 (United States); Landini, Barbara; Campman, Ken [Sumika Electronic Materials, Inc., Phoenix, Arizona 85034 (United States)

    2014-05-28

    This paper reports the proposal, design, and demonstration of ultra-thin GaAs single-junction solar cells integrated with a reflective back scattering layer to optimize light management and minimize non-radiative recombination. According to our recently developed semi-analytical model, this design offers one of the highest potential achievable efficiencies for GaAs solar cells possessing typical non-radiative recombination rates found among commercially available III-V arsenide and phosphide materials. The structure of the demonstrated solar cells consists of an In{sub 0.49}Ga{sub 0.51}P/GaAs/In{sub 0.49}Ga{sub 0.51}P double-heterostructure PN junction with an ultra-thin 300 nm thick GaAs absorber, combined with a 5 μm thick Al{sub 0.52}In{sub 0.48}P layer with a textured as-grown surface coated with Au used as a reflective back scattering layer. The final devices were fabricated using a substrate-removal and flip-chip bonding process. Solar cells with a top metal contact coverage of 9.7%, and a MgF{sub 2}/ZnS anti-reflective coating demonstrated open-circuit voltages (V{sub oc}) up to 1.00 V, short-circuit current densities (J{sub sc}) up to 24.5 mA/cm{sup 2}, and power conversion efficiencies up to 19.1%; demonstrating the feasibility of this design approach. If a commonly used 2% metal grid coverage is assumed, the anticipated J{sub sc} and conversion efficiency of these devices are expected to reach 26.6 mA/cm{sup 2} and 20.7%, respectively.

  15. The membrane estrogen receptor GPR30 mediates cadmium-induced proliferation of breast cancer cells

    International Nuclear Information System (INIS)

    Cadmium (Cd) is a nonessential metal that is dispersed throughout the environment. It is an endocrine-disrupting element which mimics estrogen, binds to estrogen receptor alpha (ERα), and promotes cell proliferation in breast cancer cells. We have previously published that Cd promotes activation of the extracellular regulated kinases, erk-1 and -2 in both ER-positive and ER-negative human breast cancer cells, suggesting that this estrogen-like effect of Cd is not associated with the ER. Here, we have investigated whether the newly appreciated transmembrane estrogen receptor, G-protein coupled receptor 30 (GPR30), may be involved in Cd-induced cell proliferation. Towards this end, we compared the effects of Cd in ER-negative human SKBR3 breast cancer cells in which endogenous GPR30 signaling was selectively inhibited using a GPR30 interfering mutant. We found that Cd concentrations from 50 to 500 nM induced a proliferative response in control vector-transfected SKBR3 cells but not in SKBR3 cells stably expressing interfering mutant. Similarly, intracellular cAMP levels increased about 2.4-fold in the vector transfectants but not in cells in which GPR30 was inactivated within 2.5 min after treatment with 500 nM Cd. Furthermore, Cd treatment rapidly activated (within 2.5 min) raf-1, mitogen-activated protein kinase kinase, mek-1, extracellular signal regulated kinases, erk-1/2, ribosomal S6 kinase, rsk, and E-26 like protein kinase, elk, about 4-fold in vector transfectants. In contrast, the activation of these signaling molecules in SKBR3 cells expressing the GPR30 mutant was only about 1.4-fold. These results demonstrate that Cd-induced breast cancer cell proliferation occurs through GPR30-mediated activation in a manner that is similar to that achieved by estrogen in these cells.

  16. Preparation and Properties of Evaporated CdTe and All Thin Film CdTe/CdS Solar Cells

    Science.gov (United States)

    Shahzad, Naseem

    1991-05-01

    Cadmium telluride thin films were prepared by vacuum evaporation of CdTe powder in an attempt to fabricate all thin film solar cells of the type CdTe/CdS. Characterization of CdTe has shown it to have a band gap of 1.522 eV and a resistivity of 22Ω-cm. As prepared, solar cells exhibited low values of output parameters. Given quantity of copper was then deposited on top of the CdTe/CdS solar cells and the whole system was annealed at 350° C. This copper doping changed the output parameters favorably with a maximum efficiency of 1.9%.

  17. Microcrystalline silicon and micromorph tandem solar cells

    Science.gov (United States)

    Keppner, H.; Meier, J.; Torres, P.; Fischer, D.; Shah, A.

    ``Micromorph'' tandem solar cells consisting of a microcrystalline silicon bottom cell and an amorphous silicon top cell are considered as one of the most promising new thin-film silicon solar-cell concepts. Their promise lies in the hope of simultaneously achieving high conversion efficiencies at relatively low manufacturing costs. The concept was introduced by IMT Neuchâtel, based on the VHF-GD (very high frequency glow discharge) deposition method. The key element of the micromorph cell is the hydrogenated microcrystalline silicon bottom cell that opens new perspectives for low-temperature thin-film crystalline silicon technology. According to our present physical understanding microcrystalline silicon can be considered to be much more complex and very different from an ideal isotropic semiconductor. So far, stabilized efficiencies of about 12% (10.7% independently confirmed) could be obtained with micromorph solar cells. The scope of this paper is to emphasize two aspects: the first one is the complexity and the variety of microcrystalline silicon. The second aspect is to point out that the deposition parameter space is very large and mainly unexploited. Nevertheless, the results obtained are very encouraging and confirm that the micromorph concept has the potential to come close to the required performance criteria concerning price and efficiency.

  18. Microcrystalline silicon and micromorph tandem solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Keppner, H. [Univ. of Appl. Sci., Le Locle (Switzerland); Meier, J.; Torres, P.; Fischer, D.; Shah, A. [Institute of Microtechnology, University of Neuchatel, A.-L. Breguet 2, CH-2000 Neuchatel (Switzerland)

    1999-08-01

    ``Micromorph`` tandem solar cells consisting of a microcrystalline silicon bottom cell and an amorphous silicon top cell are considered as one of the most promising new thin-film silicon solar-cell concepts. Their promise lies in the hope of simultaneously achieving high conversion efficiencies at relatively low manufacturing costs. The concept was introduced by IMT Neuchatel, based on the VHF-GD (very high frequency glow discharge) deposition method. The key element of the micromorph cell is the hydrogenated microcrystalline silicon bottom cell that opens new perspectives for low-temperature thin-film crystalline silicon technology. According to our present physical understanding microcrystalline silicon can be considered to be much more complex and very different from an ideal isotropic semiconductor. So far, stabilized efficiencies of about 12% (10.7% independently confirmed) could be obtained with micromorph solar cells. The scope of this paper is to emphasize two aspects: the first one is the complexity and the variety of microcrystalline silicon. The second aspect is to point out that the deposition parameter space is very large and mainly unexploited. Nevertheless, the results obtained are very encouraging and confirm that the micromorph concept has the potential to come close to the required performance criteria concerning price and efficiency. (orig.) With 13 figs., 2 tabs., 62 refs.

  19. Analysis of electroluminescence images in small-area circular CdTe solar cells

    Science.gov (United States)

    Bokalič, Matevž; Raguse, John; Sites, James R.; Topič, Marko

    2013-09-01

    The electroluminescence (EL) imaging process of small area solar cells is investigated in detail to expose optical and electrical effects that influence image acquisition and corrupt the acquired image. An approach to correct the measured EL images and to extract the exact EL radiation as emitted from the photovoltaic device is presented. EL images of circular cadmium telluride (CdTe) solar cells are obtained under different conditions. The power-law relationship between forward injection current and EL emission and a negative temperature coefficient of EL radiation are observed. The distributed Simulation Program with Integrated Circuit Emphasis (SPICE®) model of the circular CdTe solar cell is used to simulate the dark J-V curve and current distribution under the conditions used during EL measurements. Simulation results are presented as circularly averaged EL intensity profiles, which clearly show that the ratio between resistive parameters determines the current distribution in thin-film solar cells. The exact resistance values for front and back contact layers and for CdTe bulk layer are determined at different temperatures, and a negative temperature coefficient for the CdTe bulk resistance is observed.

  20. Influence of Isoflavones on Cadmium-induced Adverse Effects in Vascular Endothelial Cells (ECV 304)

    Institute of Scientific and Technical Information of China (English)

    JUE CHEN; TAI-YI JIN

    2005-01-01

    Objective To study the possible intervention of isoflavones in cytotoxicity induced by cadmium in vascular endothelial cells. Methods An ECV 304 cell line derived from human umbilical vein endothelial cells was adopted. Genistein / daidzein was added prior to or simultaneously with CdCl2, cell viability was determined by MTT assay, and metallothionein mRNA expression was monitored by RT-PCR method. Results Cell viability was higher in isoflavone and CdCl2 co-treated groups than that in CdCl2 treated group, with CdCl2 concentration at 10, 20, 40, and 80 μmol/L, respectively. However this increase was not observed in the group treated with CdCl2 at a concentration of 60 μmol/L. Isoflavones (10-10 mol/L to 10-5 mol/L) were added 24 h before cells were challenged with 80 μmol/L CdCl2 for 24 h or simultaneously with 80 μmol/L CdCl2. Genistein increased cell viability only at 10-5 mol/L, while daidzein caused a dose-dependent increase from 10-10 mol/L to 10-5 mol/L in co-treatment with CdCl2. In pre-treatment, genistein (10-7 to 10-5 mol/L) increased cell viability whereas only 10-5 mol/L of daidzein exerted protection. Apparent protection could be found when the cells were pre-treated with 10-5 mol/L isoflavones for over 12 h, whereas 24 h incubation was required in such a co-treatment, with the exception of daidzein that had a significant protection in only 3 h. Isoflavones (10-6 mol/L) incubated for 3 h to 24 h, increased MT IIA and MT IF mRNA expression, but the induction could not last for more than 24 h. Co-treatment with isoflavones could induce an additional induction of MT IIA mRNA expression in cells exposed to cadmium. However, the additional induction of MT IIA and MT IF mRNA was not seen when pre-treatment was carried out with isoflavones, with the exception of an increase in MT IIA mRNA expression in the daidzein pre-treated group. Conclusion Genistein/daidzein could reverse the cytotoxicity of cadmium either in pre-treatment or in co-treatment. The

  1. Removal of Cadmium and Zinc from Soil using Immobilized Cell of Biosurfactant Producing Bacteria

    Directory of Open Access Journals (Sweden)

    Charoon Sarin

    2010-07-01

    Full Text Available Immobilized biosurfactant producing bacteria (Bacillus subtilis TP8 and Pseudomonas fluorescens G7 were assessed for survival in heavy metal contaminated soil and for their ability to remove cadmium and zinc from contaminated soil. P. fluorescens G7 was considered to be a good candidate for bioremediation of heavy metals because of its high minimum inhibitory concentrations (MIC for each heavy metal and because of the obviously increased numbers of cell surviving after incubation in the heavy metal contaminated soil up to 4 weeks. The results of soil remediation showed that approximately 19% of Zn and 16.7% of Cd could be removed by this immobilized biosurfactant producing bacteria after incubation for 2 weeks. The results confirm the potential applicability of the immobilized biosurfactant producing bacteria for heavy metal bioremediation.

  2. Hot electron plasmon-protected solar cell.

    Science.gov (United States)

    Kong, J; Rose, A H; Yang, C; Wu, X; Merlo, J M; Burns, M J; Naughton, M J; Kempa, K

    2015-09-21

    A solar cell based on a hot electron plasmon protection effect is proposed and made plausible by simulations, non-local modeling of the response, and quantum mechanical calculations. In this cell, a thin-film, plasmonic metamaterial structure acts as both an efficient photon absorber in the visible frequency range and a plasmonic resonator in the IR range, the latter of which absorbs and protects against phonon emission the free energy of the hot electrons in an adjacent semiconductor junction. We show that in this structure, electron-plasmon scattering is much more efficient than electron-phonon scattering in cooling-off hot electrons, and the plasmon-stored energy is recoverable as an additional cell voltage. The proposed structure could become a prototype of a new generation of high efficiency solar cells. PMID:26406739

  3. 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...

  4. 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...

  5. Prepolymer Syrup for Encapsulating Solar Cells

    Science.gov (United States)

    Gupta, A.; Ingham, J. D.; Yavrouian, A. H.

    1982-01-01

    Clear polymer syrup, made by disolving n-butyl acrylate prepolymer in monomer, used to encapsulate solar cells by any of three standard processes (dipping, multiple coating, or automated machine coating). Use of cyclohexane instead of methanol/water solvent during initial polymerization stage maintains high molecular weight and raises yield of linear polymer to essentially 100 percent.

  6. Perovskite Solar Cells: Beyond Methylammonium Lead Iodide.

    Science.gov (United States)

    Boix, Pablo P; Agarwala, Shweta; Koh, Teck Ming; Mathews, Nripan; Mhaisalkar, Subodh G

    2015-03-01

    Organic-inorganic lead halide based perovskites solar cells are by far the highest efficiency solution-processed solar cells, threatening to challenge thin film and polycrystalline silicon ones. Despite the intense research in this area, concerns surrounding the long-term stability as well as the toxicity of lead in the archetypal perovskite, CH3NH3PbI3, have the potential to derail commercialization. Although the search for Pb-free perovskites have naturally shifted to other transition metal cations and formulations that replace the organic moiety, efficiencies with these substitutions are still substantially lower than those of the Pb-perovskite. The perovskite family offers rich multitudes of crystal structures and substituents with the potential to uncover new and exciting photophysical phenomena that hold the promise of higher solar cell efficiencies. In addressing materials beyond CH3NH3PbI3, this Perspective will discuss a broad palette of elemental substitutions, solid solutions, and multidimensional families that will provide the next fillip toward market viability of the perovskite solar cells. PMID:26262670

  7. 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.

  8. 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...

  9. Method of fabricating a solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Pass, Thomas; Rogers, Robert

    2016-02-16

    Methods of fabricating solar cells are described. A porous layer may be formed on a surface of a substrate, the porous layer including a plurality of particles and a plurality of voids. A solution may be dispensed into one or more regions of the porous layer to provide a patterned composite layer. The substrate may then be heated.

  10. The Environmental Pollutant Cadmium Promotes Influenza Virus Replication in MDCK Cells by Altering Their Redox State

    Directory of Open Access Journals (Sweden)

    Lucia Nencioni

    2013-02-01

    Full Text Available Cadmium (Cd is a toxic heavy metal that is considered an environmental contaminant. Several sources of human exposure to Cd, including employment in primary metal industries, production of certain batteries, foods, soil and cigarette smoke, are known. Its inhalation has been related to different respiratory diseases and toxic effects, among which alterations of the physiological redox state in individuals exposed to the metal have been described. Host-cell redox changes characteristic of oxidative stress facilitate the progression of viral infection through different mechanisms. In this paper, we have demonstrated that pre-treatment with CdCl2 of MDCK cells increased influenza virus replication in a dose-dependent manner. This phenomenon was related to increased viral protein expression (about 40% compared with untreated cells. The concentration of CdCl2, able to raise the virus titer, also induced oxidative stress. The addition of two antioxidants, a glutathione (GSH derivative or the GSH precursor, N-acetyl-L-cysteine, to Cd pre-treated and infected cells restored the intracellular redox state and significantly inhibited viral replication. In conclusion, our data demonstrate that Cd-induced oxidative stress directly increases the ability of influenza virus to replicate in the host-cell, thus suggesting that exposure to heavy metals, such as this, could be a risk factor for individuals exposed to a greater extent to the contaminant, resulting in increased severity of virus-induced respiratory diseases.

  11. Progress in quantum well solar cells

    International Nuclear Information System (INIS)

    A quantum well solar cell is a special multiple-band gap device with intermediate properties between heterojunction cells (sum of the currents generated in the different materials but voltage controlled by the lowest of the two band gaps) and tandem cells (sum of the voltages but current determined by the worst of the two sub-cells). Strain-balanced GaAsP/InGaAs multi-quantum wells move the absorption edge of GaAs solar cells closer to the optimum value for single junction cells with no need for any partially relaxed buffer layer to accommodate lattice mismatch between the absorbing layers and the substrate. Covering a large spectral range in a single-junction cell has the benefit that the cell remains close to optimal efficiency in the varying spectral conditions of a typical terrestrial concentrator. Though monolithic multi-junction cells have significantly higher efficiency, the series-current constraint means that some of this advantage is lost as the illuminating spectra and the cell temperature change from the values at which the tandem was optimised. The good material quality which can be achieved with these structures makes the cell dark current at the typical operating conditions expected under moderate sunlight concentration (∼200x), increasingly dominated by radiative processes the deeper the quantum wells. We will report on high concentration measurements of strain-balanced quantum well solar cells with and without Bragg-stack reflectors and discuss the 'additivity' between the short-circuit current and the dark-current. We discuss a 50 shallow well cell with measured AM1.5d efficiency of (26 ± 1)% at around 200x concentration. This is approximately 2% higher than a comparable p-n cell with comparable material quality. The good material quality is also responsible for another effect previously observed in single quantum wells becoming measurable in structures with 5 and 10 wells, that is the suppression of carrier recombination in quantum wells with

  12. Nonlinear behaviours of bifacial silicon solar cells

    Science.gov (United States)

    Ruiz, J. M.

    A theoretical model to account for superlinear spectral photocurrent-irradiance characteristics of solar cells is presented. The model is applied to bifacial BSF silicon cells under separate front and posterior illumination modes. Simple formulas for the internal quantum efficiencies of the base region are obtained. Ohmic electric field as well as trap-filling effects are considered to be responsible for superlinear characteristics under low-injection conditions, but usually correspond to separate ranges of influence. High-injection effects only change this behavior at very high irradiances. Back-illuminated cells are found to be much more sensible to nonlinearities than conventional front-illuminated cells.

  13. 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

  14. Fabrication and Characterization of Organic Solar Cells

    OpenAIRE

    Yengel, Emre

    2010-01-01

    Bulk heterojunction organic solar cells have recently drawn tremendous attention because of their technological advantages for actualization of large-area and cost effective fabrication. Two important criteria of these cells are efficiency and cost. The research in this dissertation focuses on the enhancement of these criteria with two different approaches. In the first approach, power conversion efficiency of organic photovoltaic devices is enhanced by introducing Deoxyribonucleic acids DNA ...

  15. 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

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

    International Nuclear Information System (INIS)

    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−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−1 dry wt, 0.5 mg L−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 for 10 and 50% of

  17. IN VITRO INHIBITION OF ACETYLCHOLINESTERASE ACTIVITY IN HUMAN RED BLOOD CELLS BY CADMIUM AND LEAD

    OpenAIRE

    Abdollahi, M.; M. Biukabadi M. A. Ebrahimzadeh

    1998-01-01

    The effects of cadmium and lead on human erythrocyte acetylcholinesterase activity were studied. Blood used in this study was obtained from 24 healthy individuals, then after hemolysation, treated with 3 various concentrations of cadmium and lead. A strong inhibition of acetylcholinesterase was noted in treated samples by cadmium and lead. The remaining activity In the case of lead, the remaining activity was found to be 81% with the highest concentration , S7% with the middle and 94% with th...

  18. 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.

  19. Application of crystalline silicon solar cells in photovoltaic modules

    OpenAIRE

    L.A. Dobrzański; A. Drygała; M. Giedroć

    2010-01-01

    Purpose: The aim of the paper is to determinate basic electrical properties of solar cells, made of them photovoltaic module and analysis of its main electrical parameters.Design/methodology/approach: In this study, several methods were used: current – voltage characteristic to determinate basic electrical properties of 36 monocrystalline silicon solar cells, soft soldering technique to bond solar cells . Photovoltaic module was produced from 31 solar cells with the largest short-circuit curr...

  20. Surface Passivation Studies on n+pp+ Bifacial Solar Cell

    OpenAIRE

    Suhaila Sepeai; M. Y. Sulaiman; Kamaruzzaman Sopian; Saleem H. Zaidi

    2012-01-01

    Bifacial solar cell is a specially designed solar cell for the production of electricity from both sides of the solar cell. It is an active field of research to make photovoltaics (PV) more competitive by increasing its efficiency and lowering its costs. We developed an n+pp+ structure for the bifacial solar cell. The fabrication used phosphorus-oxy-trichloride (POCl3) diffusion to form the emitter and Al diffusion using conventional screen printing to produce the back surface field (BSF). Th...

  1. Present status of the development of thin-film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Dhere, N.G. (Solar Energy Research Inst., Golden, CO (USA))

    1989-01-01

    The principle types of thin-film solar cells are based on single-junction and multi-junction hydrogenated amorphous silicon (a-Si:H), copper indium diselenide (CuInSe{sub 2}) and cadmium telluride (CdTe). Impressive gains in the performance of these cells have been reported in recent months. The problem of contacts to CdTe cells has been circumvented, resulting in the development of stable 11% efficient n-CdS/i-CdTe/p-ZnTe heterostructure solar cells. Total small-area (1 cm {sup 2}) efficiencies which have been measured at SERI under standard conditions (global AM 1.5) are as follows: single-junction a-Si:h, 11.5-12%; triple-junction a-Si:H:F, 12.4% (active area 13.3%); CuGaInSe {sub 2}, 14.1% (active area); CdTe, 10-11%; and CuInSe{sub 2}-a-Si:H cascade cells, 14.6%. Hydrogenated amorphous silicon solar-cell panels are being commercialized in several countries. Small-scale production of CdTe panels has also been undertaken. Recently, a CuInSe{sub 2} module with the world's highest thin-film module efficiency, 11.1% , an aperture area of 938 cm{sup 2} and a total power of 10.4 W, has been tested at SERI. (author).

  2. Fabrication of Cu2ZnSnS4 solar cell on a flexible glass substrate

    International Nuclear Information System (INIS)

    Cu2ZnSnS4 (CZTS) thin film solar cells were fabricated on 100 μm thick flexible glass (FG) substrates coated with Molybdenum (Mo) anodes. The CZTS thin films were deposited by using magnetron sputtering followed by annealing in sulfur vapor. The fabricated cell structure was FG/Mo/CZTS/CdS/ZnO/ITO/Ag, where cadmium sulfide (CdS), zinc oxide (ZnO), tin-doped indium oxide (ITO) and silver (Ag) were used as an n-type window layer, resistive layer, transparent conductor and finger electrode, respectively. The best conversion efficiency achieved of the flexible CZTS solar cell was 3.08%, with an active area of 0.45 cm2. The conversion efficiency was reduced by 20% when the cell was bent to a 50 mm radius. - Highlights: • Flexible Cu2ZnSnS4 solar cell on a 100 μm thick Corning® Willow® Glass substrate • Cell efficiency of 3.1% is achieved on the flexible glass. • Efficiency was reduced to 2.41% when bent at a 50 mm radius

  3. Photovoltaics and solar thermal conversion to electricity - Status and prospects

    Science.gov (United States)

    Alper, M. E.

    1979-01-01

    Photovoltaic power system technology development includes flat-plate silicon solar arrays and concentrating solar cell systems, which use silicon and other cell materials such as gallium arsenide. System designs and applications include small remote power systems ranging in size from tens of watts to tens of kilowatts, intermediate load-center applications ranging in size from tens to hundreds of kilowatts, and large central plant installations, as well as grid-connected rooftop applications. The thermal conversion program is concerned with large central power systems and small power applications.

  4. A comparative investigation of DNA strand breaks, sister chromatid exchanges and K-ras gene mutations induced by cadmium salts in cultured human cells

    International Nuclear Information System (INIS)

    Cadmium (Cd) is a toxic heavy metal of continuing occupational and environmental concern with a wide variety of adverse effects. Several studies have shown that cadmium produces DNA strand breaks, DNA-protein cross-links, oxidative DNA damage, chromosomal aberrations, dysregulation of gene expression resulting in enhanced proliferation, depressed apoptosis and/or altered DNA repair. This study was undertaken to investigate the ability of cadmium chloride (CdCl2) and cadmium sulphate (CdSO4) to induce point mutations in codon 12 of the K-ras protooncogene assessed by polymerase chain reaction-single strand conformation polymorphisms (PCR-SSCP) and RFLP-enriched PCR methods. Also their genotoxic effects were analyzed by the comet assay and sister chromatid exchanges test. The human lung fibroblast cell line MRC-5 was used for the experiments. Sister chromatid exchanges assay (SCEs) frequencies were significantly increased in cells exposed to cadmium salts in relation to controls (p < 0.001). Despite the slow increment observed in the three comet parameters considered when cells were treated with cadmium chloride, significant differences between groups were only found in the variable comet moment (CM) (p < 0.005). On the other hand, when cells were exposed to cadmium sulphate, the Kruskal-Wallis test showed highly significant differences between groups for migration, tail moment and comet moment parameters (p < 0.001). Nevertheless, a null or weak point mutation induction in K-ras protooncogene was detected using polymerase chain reaction-low ionic strength-single strand conformation polymorphisms (PCR-LIS-SSCP) and RFLP-enriched PCR methods when cells were treated with cadmium salts. Thus, inorganic cadmium produces genotoxicity in human lung fibroblast MRC-5 cells, in the absence of significant point mutation of the K-ras gene

  5. 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.

  6. Flexible thermal cycle test equipment for concentrator solar cells

    Science.gov (United States)

    Hebert, Peter H.; Brandt, Randolph J.

    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.

  7. A Cost Roadmap for Silicon Heterojunction Solar Cells

    NARCIS (Netherlands)

    Louwen, A.; van Sark, W.G.J.H.M.; Schropp, Ruud; Faaij, A.

    2016-01-01

    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

  8. Effects of cadmium on haemopoiesis in irradiated and non-irradiated mice: 1. Relationship to the number of myeloid progenitor cells

    International Nuclear Information System (INIS)

    The effects of a single subcutaneous injection of cadmium chloride on hemopoiesis in normal (non-irradiated) or irradiated mice were investigated. The cadmium doses ranged from 1 to 8 mg/kg body weight. Twenty-four hours after treatment with cadmium (3 to 8 mg/kg) there were no significant changes in the bone marrow cellularity or the granulocyte-macrophage progenitor cell (GM-CFC) number per femur in non-irradiated female ICR mice. Similarly, during the 30-day postinjection period, the bone marrow cellularity and marrow GM-CFC number in mice treated with a cadmium dose of 5 mg/kg were not significantly different from the control values. Cadmium reduced the lethal effects of gamma rays significantly. In addition, increasing the doses of cadmium administered 24 h prior to sublethal irradiation increased the number of endogenous hemopoietic stem cells (endoCFU-S) in a concentration-dependent manner. Pretreatment with cadmium also decreased the radiation damage to endoCFU-S and hemopoietic progenitor cells committed to granulocyte/macrophage development (GM-CFC). The survival of stem cells was higher and the regeneration of cellularity and GM-CFC of irradiated bone marrow was accelerated in mice pretreated with 5 mg Cd/kg body weight in comparison with saline-injected mice. 1 tab., 7 figs., 28 refs

  9. 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.

  10. Superstrate sub-cell voltage-matched multijunction solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Mascarenhas, Angelo; Alberi, Kirstin

    2016-03-15

    Voltage-matched thin film multijunction solar cell and methods of producing cells having upper CdTe pn junction layers formed on a transparent substrate which in the completed device is operatively positioned in a superstate configuration. The solar cell also includes a lower pn junction formed independently of the CdTe pn junction and an insulating layer between CdTe and lower pn junctions. The voltage-matched thin film multijunction solar cells further include a parallel connection between the CdTe pn junction and lower pn junctions to form a two-terminal photonic device. Methods of fabricating devices from independently produced upper CdTe junction layers and lower junction layers are also disclosed.

  11. C-Si solar cell modules

    International Nuclear Information System (INIS)

    In order to meet the rapidly growing demand for solar power photovoltaic systems which is based on public consciousness of global environmental issues, SHARP has increased the production of solar cells and modules over 10-fold in the last 5 years. Silicon-based technologies are expected to be dominant in the coming decade. In the course of an increase of the annual production scale to 1000 MW, the efficiency of modules will be improved and the thickness of wafers will be decreased and all this will lead to a drastic price reduction of PV systems. (Author)

  12. Cadmium and cisplatin damage erythropoietin-producing proximal renal tubular cells

    Energy Technology Data Exchange (ETDEWEB)

    Horiguchi, Hyogo; Oguma, Etsuko; Kayama, Fujio [Jichi Medical School, Division of Environmental Medicine, Center for Community Medicine, Tochigi (Japan); Core Research for Evolutional Science and Technology, Japan Science Technology Corporation (CREST-JST), Saitama (Japan)

    2006-10-15

    The concomitant manifestations of proximal renal tubular dysfunction and anemia with erythropoietin (Epo) deficiency observed in chronic cadmium (Cd) intoxication, such as Itai-itai disease, suggest a close local correlation between the Cd-targeted tubular cells and Epo-producing cells in the kidney. Therefore, we investigated the local relationship between hypoxia-induced Epo production and renal tubular injury in rats injected with Cd at 2 mg/kg twice a week for 8 months. Anemia due to insufficient production of Epo was observed in Cd-intoxicated rats. In situ hybridization detected Epo mRNA expression in the proximal renal tubular cells of hypoxic rats without Cd intoxication, and the Cd-intoxicated rats showed atrophy of Epo-expressing renal tubules and replacement of them with fibrotic tissue. A single dose of cisplatin at 8 mg/kg, which can induce clinical manifestations similar to those of Cd including renal tubular damage along with Epo-deficient anemia, resulted in Epo-expressing renal tubule destruction on day 4. These data indicate that Cd and cisplatin would induce anemia through the direct injury of the proximal renal tubular cells that are responsible for Epo production. (orig.)

  13. Dynamic kirigami structures for integrated solar tracking

    Science.gov (United States)

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

    2015-09-01

    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.

  14. Management of light absorption in extraordinary optical transmission based ultra-thin-film tandem solar cells

    Science.gov (United States)

    Mashooq, Kishwar; Talukder, Muhammad Anisuzzaman

    2016-05-01

    polygon, total absorption remains approximately the same. However, the total absorption suffers significantly if the holes are triangle. The transmission spectra of incident light into the bottom subcell, and hence the absorption, change significantly for square and circle holes if the active materials change to cadmium selenide (CdSe) and cadmium telluride (CdTe) in the top and bottom subcells, respectively. Although the intermediate metal layer may induce electron-hole pair recombination due to surface defects, the short-circuit current density of an ultra-thin plasmonic solar cell with an intermediate metal layer with two-dimensional hole array is >9% of that of a structure without the intermediate metal layer.

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

    Science.gov (United States)

    Malea, Paraskevi; Adamakis, Ioannis-Dimosthenis S; Kevrekidis, Theodoros

    2013-11-15

    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(-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 (98.5-128.9μgg(-1)drywt, 0.5 mg L(-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 for 10 and 50% of cells to die tended to decrease as the uptake velocity increased; in particular, significant negative correlations were found between these variables. These results suggest that toxicity appears to be a function of cadmium uptake rate rather than of the total tissue metal concentration. Hence, tissue residues should be interpreted in relation to the time frame of the exposure, while the estimation of metal uptake velocity could be utilized for

  16. 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

  17. 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

  18. Cu(In,Ga)Se2 and Related Solar Cells

    Science.gov (United States)

    Rau, Uwe; Schock, Hans W.

    2015-10-01

    The following sections are included: * Introduction * Material properties * Cell and module technology * Device physics * Wide-gap chalcopyrites * Kesterite (CZTS) solar cells * Conclusions * References

  19. Progress towards high efficiency thin film CdTe solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, K.W.; Eberspacher, C.; Cohen, F.; Avery, J.; Duran, G.; Bottenberg, W.

    1988-01-15

    This paper describes work investigating high rate cadmium telluride (CdTe) film deposition by close-space vapor transport, leading to 4 cm/sup 2/ tin oxide/CdTe solar cells of efficiency greater than 10%. Under a 100 mW cm/sup -2/ air mass 1.5 global spectrum, a cell of efficiency 10.5% had a short-circuit current of 28.1 mA cm/sup -2/, an open circuit voltage of 0.663 V and a fill factor of 0.563. Our major achievements include (1) the use of completely nonvacuum processing, (2) the fabrication of simple transparent conductive oxide/CdTe cells without need of a CdS window layer, and (3) screenprinted back contacts.

  20. Solar Cell Production in Nigeria: Prospects, Options and Problems

    International Nuclear Information System (INIS)

    The prospects and problems facing solar cell production in Nigeria are discussed. The paper reviews many proven solar cell materials in terms of their current efficiencies and production costs. Silicon solar cell production appears to be the best technology option for Nigeria because of the abundant quartz sand and waste products from our phosphate fertiliser company that can be employed as starting materials to produce solar grade silicon. Factors affecting solar cell efficiency, choice of solar cell as well as financial and material problems limiting the progress on silicon solar cell production are also discussed. Finally, the paper recommends the simultaneous production of solar grade silicon and coordinated development of the balance of system components as first steps towards actualizing this objective

  1. 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.

  2. 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)

  3. Immunohistochemical study of cell proliferation, Bcl-2, p53, and caspase-3 expression on preneoplastic changes induced by cadmium and zinc chloride in the ventral rat prostate.

    OpenAIRE

    Arriazu, Riánsares; José M Pozuelo; Henriques-Gil, Nuno; Perucho, Teresa; Martín, Rocío; Rodríguez, Rosario; Santamaría, Luis

    2006-01-01

    KEYWORDS CLASSIFICATION: Animals;Apoptosis;biosynthesis;Biology;chemically induced;Cadmium;Cadmium Chloride;Carcinogens;Caspase 3;Caspases;Cell Proliferation;Chlorides;Immunohistochemistry;metabolism;Male;mechanisms of carcinogenesis;pathology;pharmacology;Precancerous Conditions;Proliferating Cell Nuclear Antigen;Prostate;Prostatic Intraepithelial Neoplasia;Prostatic Neoplasms;Proteins;Proto-Oncogene Proteins;Proto-Oncogene Proteins c-bcl-2;Rats;Rats,Sprague-Dawley;Research;Spain;toxicity;Ti...

  4. Cell Surface Display of Four Types of Solanum nigrum Metallothionein on Saccharomyces cerevisiae for Biosorption of Cadmium.

    Science.gov (United States)

    Wei, Qinguo; Zhang, Honghai; Guo, Dongge; Ma, Shisheng

    2016-05-28

    We displayed four types of Solanum nigrum metallothionein (SMT) for the first time on the surface of Saccharomyces cerevisiae using an α-agglutinin-based display system. The SMT genes were amplified by RT-PCR. The plasmid pYES2 was used to construct the expression vector. Transformed yeast strains were confirmed by PCR amplification and custom sequencing. Surface-expressed metallothioneins were indirectly indicated by the enhanced cadmium sorption capacity. Flame atomic absorption spectrophotometry was used to examine the concentration of Cd(2+) in this study. The transformed yeast strains showed much higher resistance ability to Cd(2+) compared with the control. Strikingly, their Cd(2+) accumulation was almost twice as much as that of the wild-type yeast cells. Furthermore, surface-engineered yeast strains could effectively adsorb ultra-trace cadmium and accumulate Cd(2+) under a wide range of pH levels, from 3 to 7, without disturbing the Cu(2+) and Hg(2+). Four types of surfaceengineered Saccharomyces cerevisiae strains were constructed and they could be used to purify Cd(2+)-contaminated water and adsorb ultra-trace cadmium effectively. The surface-engineered Saccharomyces cerevisiae strains would be useful tools for the bioremediation and biosorption of environmental cadmium contaminants. PMID:26838339

  5. Midkine secretion protects Hep3B cells from cadmium induced cellular damage

    Institute of Scientific and Technical Information of China (English)

    Nuray Yazihan; Haluk Ataoglu; Ethem Akcil; Burcu Yener; Bulent Salman; Cengiz Aydin

    2008-01-01

    AIM:To evaluate role of midkine secretion during Cadmium (Cd) exposure in the human hepatocyte cell line Hep3B cells.METHODS: Different dosages of Cd (0.5-1-5-10 μg/mL) were applied to Hep3B cells and their effects to apoptosis, lactate dehydrogenase (LDH) leakage and midkine secretion were evaluated as time dependent manner. Same experiments were repeated with exogenously applied midkine (250-5000 pg/mL) and/or 5μg/mL Cd.RESULTS: Cd exposure induced prominent apoptosis and LDH leakage beginning from lower dosages at the 48th h. Cd induced midkine secretion with higher dosages (P < 0.001), (control, Cd 0.5-1-5-10μg/mL respectively: 1123±73, 1157±63, 1242±90, 1886± 175, 1712±166 pg/mL). Exogenous 500-5000 pg/mL midkine application during 5 μg/mL Cd toxicity prevented caspase-3 activation (control, Cd toxicity, 250, 500, 1000, 2500, 5000 pg/mL midkine+ Cd toxicity, respectively:374±64, 1786±156, 1545±179, 1203±113, 974±116, 646±56, 556±63 cfu) LDH leakage and cell death in Hep3B cells (P < 0.001).CONCLUSION: Our results showed that midkine secretion from Hep3B cells during Cd exposure protects liver cells from Cd induced cellular damage. Midkine has anti-apoptotic and cytoprotective role during Cd toxicity. Further studies are needed to explain the mechanism of midkine secretion and cytoprotective role of midkine during Cd exposure. Midkine may be a promising theurapatic agent in different toxic hepatic diseases.

  6. 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

  7. Design of a Pneumatic Robotic Arm for Solar Cell Tester System By using PLC controller

    Directory of Open Access Journals (Sweden)

    Yousif I. Al Mashhadany

    2013-01-01

    Full Text Available Solar cell testers sort photovoltaic cells according to their electrical performance, tested under simulated sunlight. A variety of testers exist, but they all face a common challenge of handling cells that are very small and thin, which makes it difficult to transport the cells from the conveyer to the storage box. This paper presents a new design for a handling robot with vacuum end-effectors, which uses a PLC controller to govern the movement of the cells and the testing process. The design applies to solar cell testers for monocrystalline, polycrystalline, cadmium telluride (CdTe, and copper indium diselenide (CIS cells. Each cell is tested for efficiency and categorized accordingly into four groups (A to D. A Virtual Reality (VR model was built to simulate the system, keeping in mind real world constraints. Two photoelectric sensors were used to make detections for both the testing process and the robot movement. The PLC controller guides the trajectory of the robot according to the results of the efficiency testing. It was seen that the system worked very well, with the testing process and the robot movement interacting smoothly. The robot trajectory was seen to be highly accurate, and the pick and place operations were done with great precision.

  8. Optimization of multijunction solar cells through indoor energy yield measurements

    OpenAIRE

    García Vara, Iván; Mcmahon, William E.; Steiner, Myles A.; Geisz, John F.; Habte, Aron; Friedman, Daniel J.

    2015-01-01

    The variability of the solar spectra in the field may reduce the annual energy yield of multijunction solar cells. It would, therefore, be desirable to implement a cell design procedure based on the maximization of the annual energy yield. In this study, we present a measurement technique to generate maps of the real performance of the solar cell for a range of light spectrum contents using a solar simulator with a computer-controllable spectral content. These performance maps are demonstrate...

  9. Nanoparticle sensitisation of solid-state nanocrystalline solar cell

    OpenAIRE

    Plass, Robert; Grätzel, Michael

    2005-01-01

    Over the past fifteen years dye-sensitised nanocrystalline solar cells have been the subject of intense research and development efforts. These systems provide a technically and economically credible alternative to classical p-n junction solar cells, reaching over 10 % certified efficiency under standard solar illumination conditions (AM 1.5, 1000 W/m2). Recently, the liquid electrolyte, commonly used in these dye-sensitised solar cells, could successfully be replaced by a novel solid hole-co...

  10. Recent advances in sensitized mesoscopic solar cells.

    Science.gov (United States)

    Grätzel, Michael

    2009-11-17

    Perhaps the largest challenge for our global society is to find ways to replace the slowly but inevitably vanishing fossil fuel supplies by renewable resources and, at the same time, avoid negative effects from the current energy system on climate, environment, and health. The quality of human life to a large degree depends upon the availability of clean energy sources. The worldwide power consumption is expected to double in the next 3 decades because of the increase in world population and the rising demand of energy in the developing countries. This implies enhanced depletion of fossil fuel reserves, leading to further aggravation of the environmental pollution. As a consequence of dwindling resources, a huge power supply gap of 14 terawatts is expected to open up by year 2050 equaling today's entire consumption, thus threatening to create a planetary emergency of gigantic dimensions. Solar energy is expected to play a crucial role as a future energy source. The sun provides about 120,000 terawatts to the earth's surface, which amounts to 6000 times the present rate of the world's energy consumption. However, capturing solar energy and converting it to electricity or chemical fuels, such as hydrogen, at low cost and using abundantly available raw materials remains a huge challenge. Chemistry is expected to make pivotal contributions to identify environmentally friendly solutions to this energy problem. One area of great promise is that of solar converters generally referred to as "organic photovoltaic cells" (OPV) that employ organic constituents for light harvesting or charge carrier transport. While this field is still in its infancy, it is receiving enormous research attention, with the number of publications growing exponentially over the past decade. The advantage of this new generation of solar cells is that they can be produced at low cost, i.e., potentially less than 1 U.S. $/peak watt. Some but not all OPV embodiments can avoid the expensive and energy

  11. 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.

  12. A Physics-based Analytical Model for Perovskite Solar Cells

    OpenAIRE

    Sun, Xingshu; Asadpour, Reza; Nie, Wanyi; Mohite, Aditya D.; Alam, Muhammad A.

    2015-01-01

    Perovskites are promising next-generation absorber materials for low-cost and high-efficiency solar cells. Although perovskite cells are configured similar to the classical solar cells, their operation is unique and requires development of a new physical model for characterization, optimization of the cells, and prediction of the panel performance. In this paper, we develop such a physics-based analytical model to describe the operation of different types of perovskite solar cells, explicitly...

  13. 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.

  14. Light trapping in thin film organic solar cells

    Directory of Open Access Journals (Sweden)

    Zheng Tang

    2014-10-01

    Full Text Available A major issue in organic solar cells is the poor mobility and recombination of the photogenerated charge carriers. The active layer has to be kept thin to facilitate charge transport and minimize recombination losses. However, optical losses due to inefficient light absorption in the thin active layers can be considerable in organic solar cells. Therefore, light trapping schemes are critically important for efficient organic solar cells. Traditional light trapping schemes for thick solar cells need to be modified for organic thin film solar cells in which coherent optics and wave effects play a significant role. In this review, we discuss the light trapping schemes for organic thin film solar cells, which includes geometric engineering of the structure of the solar cell at the micro and nanoscale, plasmonic structures, and more.

  15. 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.

  16. Review on the application of nanostructure materials in solar cells

    Science.gov (United States)

    Afshar, Elham N.; Xosrovashvili, Georgi; Rouhi, Rasoul; Gorji, Nima E.

    2015-07-01

    In recent years, nanostructure materials have opened a promising route to future of the renewable sources, especially in the solar cells. This paper considers the advantages of nanostructure materials in improving the performance and stability of the solar cell structures. These structures have been employed for various performance/energy conversion enhancement strategies. Here, we have investigated four types of nanostructures applied in solar cells, where all of them are named as quantum solar cells. We have also discussed recent development of quantum dot nanoparticles and carbon nanotubes enabling quantum solar cells to be competitive with the conventional solar cells. Furthermore, the advantages, disadvantages and industrializing challenges of nanostructured solar cells have been investigated.

  17. 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.

  18. Metal nanoparticles for thin film solar cells

    DEFF Research Database (Denmark)

    Gritti, Claudia

    nanoantennas absorbing photons with energy smaller than the semiconductor gap but larger than the Schottky barrier height between metal and semiconductor. The optimization of the fabrication process of GaAs and a-Si:H Schottky solar cells is first conducted and subsequently, the incorporation of Au or Ag...... efficiency in such spectral range; after an overview of the different technologies available today, the employment of localized surface plasmons (LSPs) through the incorporation of metallic nanoparticles within the photovoltaic device is chosen as a cheap and simple method. The LSP resonance wavelength...... to increase light trapping and can come along regardless, we aim, as first target, to absorb forbidden (for the semiconductor) photons by the NPs which can excite hot electrons inside the metal NP and emit them directly into the conduction band of the solar cell semiconductor, without going through...

  19. Photovoltage analysis of a heterojunction solar cell

    International Nuclear Information System (INIS)

    According to the p—n junction model of Shockley, the relationship between the equilibrium carrier concentrations of n-type and p-type semiconductors on the edges of the depletion region of a p—n junction solar cell is analysed. The calculation results show that the photovoltage can exceed the built-in voltage for a special kind of heterojunction solar cell. When the photovoltage exceeds the built-in voltage under illumination, the dark current and the photocurrent are impeded by the peak of voltage barrier at the interface and the expression of the total I—V characteristic is given. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  20. 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

  1. Optical Management Techniques for Organic Solar Cells

    CERN Document Server

    Rajagopal, Adharsh

    2016-01-01

    In this thesis, two different optical management techniques for organics based solar cells are explored. The first part is focused on the development of a textured rear reflector for OPVs. The use of textured reflector (TR) facilitates an increase in the optical path length along with light trapping within the active layer. TR was fabricated through a relatively simpler technique by depositing metal films over a microlens array (MLA). Zinc oxide nanoparticles were used to minimize the shadowing effect. Using TR, enhancements in short-circuit current density and power conversion efficiencies up to 10-25% were demonstrated for a polymer based organic solar cell. The second part is focused on improving the effectiveness of MLA incorporation in OPVs. The increase in path length achieved using MLA can be improved by increasing the refractive index of MLA and incorporating MLA directly on the transparent electrode instead of glass substrate. This approach could avoid the optical losses occurring at the interface be...

  2. Hybrid Automatic Solar Tracking System for Different Types of Solar Cells: A review.

    OpenAIRE

    Neha Sonkar; Pankaj J Edla; Dr. Bhupendra Gupta

    2013-01-01

    The objective of this paper is to present review on the use of different material of Solar panel in a solar tracking system at Stationary, Single Axis, Dual Axis & Hybrid Axis solar tracker to have better performance with minimum losses to the surroundings, as the solar tracker ensures maximum intensity of sun rays hitting the surface of the panel from sunrise to sunset. Solar cells are playing a role of increasing importance in household and other areas of electricity consumption. Due to the...

  3. Photocatodes for Dye-Sensitized Solar Cells

    Czech Academy of Sciences Publication Activity Database

    Krýsová, Hana; Petrák, Václav; Yeap, W. S.; Verstappen, P.; Maes, W.; Haenen, K.; Gao, F.; Nebel, C. E.; Kavan, Ladislav

    Prague: University of Chemistry and Technology Prague, 2015 - (Krýsa, J.). s. 17-18 ISBN 978-80-7080-931-0. [New Trends in Application of Photo and Electro Catalysis. 25.05.2015-27.05.2015, Hnanice] R&D Projects: GA ČR GA13-31783S Institutional support: RVO:61388955 ; RVO:68378271 Keywords : photocatodes * dye-sensitized solar cells * electrochemistry Subject RIV: CG - Electrochemistry

  4. Nanophotonic front electrodes for perovskite solar cells

    OpenAIRE

    Paetzold, Ulrich Wilhelm; Qiu, Weiming; Finger, Friedhelm; POORTMANS, Jef; Cheyns, David

    2015-01-01

    In less than 3 years' time, a vast progress in power conversion efficiencies of organometal halide perovskite solar cells has been achieved by optimization of the device architecture, charge transport layers, and interfaces. A further increase in these efficiencies is expected from an improvement in the optical properties via anti-reflection coatings and nanophotonic light management concepts. In this contribution, we report on the development and implementation of a nanophotonic front electr...

  5. Recent developments in thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Dhere, N.G. (Inst. Militar de Engenharia, Rio de Janeiro, RJ (Brazil))

    1990-12-15

    In recent years, remarkable progress has been made in improving the photovoltaic (PV) conversion efficiencies of thin film solar cells. The best active-area efficiencies (air mass 1.5) of thin film solar cells reported are as follows: polycrystalline CuInSe{sub 2}, 14.1%; CuIn(Ga)Se{sub 2}, 12.9%; CdTe, 12.3%, total area; single-junction hydrogenated amorphous silicon (a-Si:H), 12.0%; multiple-junction a-Si:H, 13.3%; cleaved epitaxial GaAs-Ga{sub 1-x}Al{sub x}As, 21.5%, total area. Laboratory methods for preparing small thin film solar cells are evaporation, closed-space sublimation, closed-space vapor transport, vapor phase epitaxy and metallo-organic chemical vapor deposition, while economic large-area deposition techniques such as sputtering, glow discharge reduction, electrodeposition, spraying and screen printing are being used for module fabrication. The following aperture-area efficiencies have been measured, at the Solar Energy Research Inst., for thin film modules: a-Si:H, 9.8%, 933 cm{sup 2}; CuIn(Ga)Se{sub 2}, 11.1%, 938 cm{sup 2}; CdTe, 7.3%, 838 cm{sup 2}. The instability issue of a-Si:H continues to be a high priority area. It is necessary to improve the open-circuit voltage of CuIn(Ga)Se{sub 2} cells, which do not seem to exhibit any intrinsic degradation mechanisms. With continued progress and increased production, PV modules are likely to become competitive for medium-scale power requirements in the mid-1990s. (orig.).

  6. Transparent Electrodes for Organic Solar Cells

    OpenAIRE

    Selzer, Franz

    2016-01-01

    The aim of this work was to investigate silver nanowire as well as carbon nanotube networks as transparent conducting electrodes for small molecule organic solar cells. In the framework of the nanowire investigations, a low-temperature method at less than 80 °C is developed to obtain highly conductive networks directly after the deposition and without post-processing. In detail, specific non-conductive organic materials act as a matrix where the nanowires are embedded in such that a mutua...

  7. 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.

  8. Silicon Thin-Film Solar Cells

    OpenAIRE

    2007-01-01

    We review the field of thin-film silicon solar cells with an active layer thickness of a few micrometers. These technologies can potentially lead to low cost through lower material costs than conventional modules, but do not suffer from some critical drawbacks of other thin-film technologies, such as limited supply of basic materials or toxicity of the components. Amorphous Si technology is the oldest and best established thin-film silicon technology. Amorphous silicon is deposited at low t...

  9. Singlet Fission: Towards Efficient Solar Cells

    Czech Academy of Sciences Publication Activity Database

    Havlas, Zdeněk; Wen, Jin; Michl, Josef

    Melville: AIP Publishing, 2015 - (Simos, T.; Kalogiratou, Z.; Monovasilis, T.), s. 090017. (AIP Conference Proceedings. 1702). ISBN 978-0-7354-1349-8. ISSN 0094-243X. [International Conference of Computational Methods in Sciences and Engineering /11./ (ICCMSE 2015). Athens (GR), 20.03.2015-23.03.2015] Institutional support: RVO:61388963 Keywords : solar cell * singlet fission * chromophore * energy transfer Subject RIV: CF - Physical ; Theoretical Chemistry

  10. Dye Sensitised Solar Cells: A Computational Approach

    OpenAIRE

    O Rourke, C.

    2013-01-01

    Dye sensitised solar cells (DSSCs) mimic charge excitation and transfer processes found in natural photosynthesis to directly convert sunlight into electricity. Combining easy assembly with relatively cheap materials they offer a potentially cost effective solution to our energy requirements. Numerous physical processes are at work within a DSSC and the underlying complexity of these competing processes has meant that, despite considerable research effort, advances in obtaining a viable devic...

  11. High performance polymer tandem solar cell

    OpenAIRE

    Wilson Jose da Silva; Fabio Kurt Schneider; Abd. Rashid bin Mohd Yusoff; Jin Jang

    2015-01-01

    A power conversion efficiency of 9.02% is obtained for a fully solution-processed polymer tandem solar cell, based on the diketopyrrolopyrrole unit polymer as a low bandgap photoactive material in the rear subcell, in conjunction with a new robust interconnecting layer. This interconnecting layer is optically transparent, electrically conductive, and physically strong, thus, the charges can be collected and recombined in the interconnecting layer under illumination, while the charge is genera...

  12. Polymer solar cells with plasmonic nanoparticles

    Czech Academy of Sciences Publication Activity Database

    Kazim, Samrana; Tran, Vinh Son; Halašová, Klára; Pfleger, Jiří

    Dresden: Leibniz-Institut für Polymerforschung Dresden e. V, 2012. s. 42. [IPF Colloquium Functional Polymers and Composites for Applications in Organic Electronics and Sensorics /10./. 07.11.2012-08.11.2012, Dresden] R&D Projects: GA TA ČR TE01020022 EU Projects: European Commission(XE) 290490 - ECNP-GROWTH Institutional support: RVO:61389013 Keywords : solar cell * plasmonics Subject RIV: CG - Electrochemistry

  13. Solar energy conversion by chloroplast photoelectrochemical cells

    Science.gov (United States)

    Bhardwaj, R.; Pan, R. L.; Gross, E. L.

    1981-01-01

    A photoelectrochemical cell based on chloroplasts which generates large photovoltages and photocurrents from solar energy is presented. The cell contains broken Type C chloroplasts placed on a filter separating compartments containing an electron acceptor and electron donor with platinum electrodes in each. Photovoltages were observed across a load resistance of 3000 ohms with either flavin mononucleotide or anthroquinone 2-sulphonate as the electron acceptor and dichlorophenol indophenol as the donor, and persisted for 1-2 hr after the light was turned off. The powers and short circuit currents obtained in the chloroplast cells are nearly equal to those obtained in cells based on isolated photosystem I particles. Finally, an efficiency of 2.3% has been measured for the chloroplast contribution to the total power in flavin mononucleotide cells.

  14. CdS and CdS/CdSe sensitized ZnO nanorod array solar cells prepared by a solution ions exchange process

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • CdS and CdS/CdSe quantum dots are assembled on ZnO nanorods by ion exchange process. • The CdS/CdSe sensitization of ZnO effectively extends the absorption spectrum. • The performance of ZnO/CdS/CdSe cell is improved by extending absorption spectrum. - Abstract: In this paper, cadmium sulfide (CdS) and cadmium sulfide/cadmium selenide (CdS/CdSe) quantum dots (QDs) are assembled onto ZnO nanorod arrays by a solution ion exchange process for QD-sensitized solar cell application. The morphology, composition and absorption properties of different photoanodes were characterized with scanning electron microscope, transmission electron microscope, energy-dispersive X-ray spectrum and Raman spectrum in detail. It is shown that conformal and uniform CdS and CdS/CdSe shells can grow on ZnO nanorod cores. Quantum dot sensitized solar cells based on ZnO/CdS and ZnO/CdS/CdSe nanocable arrays were assembled with gold counter electrode and polysulfide electrolyte solution. The CdS/CdSe sensitization of ZnO can effectively extend the absorption spectrum up to 650 nm, which has a remarkable impact on the performance of a photovoltaic device by extending the absorption spectrum. Preliminary results show one fourth improvement in solar cell efficiency

  15. 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.

  16. Recent progress in crystalline silicon solar cells

    International Nuclear Information System (INIS)

    In 1954, a solar cell was proposed for the first time that uses a Si pn-junction. The first and today still important application was as power generator for satellites in space. For this purpose, reliable, high performance, specially adapted and therefore expensive single crystal Si solar cells were developed. Since the beginning of the last decade, photovoltaics have been widely studied and developed as a new energy source for terrestrial use. So, research has been carried out from the point of view of materials, fabrication processes, structures and systems. First efforts aimed mainly at strong cost reductions. The results are the development of new low-cost and high-throughput cell fabrication technologies as screen-printing and the use of polycrystalline silicon as base material. However, progress in development of a new ''solar-grade'' silicon sheet material was slower and potential for cost reduction in module/system fabrication was smaller as expected originally. Consequently, since most silicon and module material costs are area-related, various tries to improve the efficiency have been undertaken. In this report, recent progress in the above mentioned topics will be reviewed. Besides this, some aspects of the module fabrication and performance will be discussed and some interesting applications presented. 89 refs, 33 figs, 2 tabs

  17. Cytotoxic and Oxidative Stress Caused by Cadmium and Lead on Human Skin Fibroblast Cells

    Directory of Open Access Journals (Sweden)

    Ali Beman Zaree Mahmodabady

    2006-01-01

    Full Text Available Introduction: Heavy metals are important occupational andenvironmental pollutants that cause damage to various organs.Although there is no effective therapy for such a poisoning,metallothionein has been shown to play a key role in thedetoxification of cadmium (Cd. Evidence in the literature suggeststhat superoxide dismutase, glutathione peroxidase, and catalaseconstitute important defense mechanisms against oxygen toxicity inthe cells. The aim of this study was to investigate the effect ofcadmium chloride and Pb-acetate on antioxidant enzymes in thehuman skin fibroblast cells (HF2FF.Material and Methods: The human skin fibroblast (HF2FF cellswere incubated in serum-free medium containing 20 μM CdCl2 for18 hr three times a week. The same exposure to an equimolar doseof Pb-acetate was performed. After each exposure and after threetimes exposure the cells were collected and cell viability, thecontents of superoxide dismutase (SOD, catalase, glutathioneperoxidase (GSH-Px, GSH and malondialdehyde (MDA weremeasured.Results: Cd caused cytotoxicity and inhibition of glutathioneperoxidase (GSH-Px and SOD activity, as well as depletion of thereduced form of glutathione (GSH in the cell. The level of lipidperoxidation (LP was increased, but catalase activity was notsignificantly altered. These defects were increased with repeatedexposures. The same exposure to an equimolar dose of Pb-acetateevoked only inhibition of GSH-Px and SOD. The values of GSH,catalase and LP activity remained unchanged.Conclusion: The inhibition of GSH-Px and SOD may be consideredas an important biomarker of the toxic effect of metals.

  18. Biosorption of Cadmium and Manganese Using Free Cells of Klebsiella sp. Isolated from Waste Water.

    Directory of Open Access Journals (Sweden)

    Yunnan Hou

    Full Text Available 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.

  19. Cadmium chloride strongly enhances cyclophosphamide-induced chromosome aberrations in mouse bone marrow cells

    Energy Technology Data Exchange (ETDEWEB)

    Pandurangarao, V.L.; Blazina, S.; Bherje, R. [Western Michigan Univ., Kalamazoo, MI (United States)] [and others

    1997-10-01

    Earlier we reported that a single 5 mg cadmium chloride (CdCl{sub 2})/kg ip dose enhanced chromosome aberrations (ca) with 50 mg/kg cyclophosphamide (CP) in mouse bone marrow cells. In this report groups of 4 mice were injected ip with saline, 0.31, 0.62, 1.25, 2.5 or 5.0 mg/kg CdCl{sub 2}, followed by saline injections at 24 h. Other mice similarly uninjected at 0 h were injected with 50 mg/kg CP at 24 h. All the mice were injected ip with 4 mg colchicine/kg at 44 h. At 48 h the bone marrow cells were processed for chromosome spreads. After dissection, visual examination revealed obvious internal hemorrhaging of the testes at 1.25 CdCl{sub 2} mg/kg and higher doses. This effect was not further increased by CP treatment. The lowest ca enhancing dose of CdCl{sub 2} on CP was 0.625 mg/kg. Our hypothesis is that Cd replaces zinc presents in numerous DNA repair enzymes and proteins resulting in diminished repair. Subsequently, the excess of unrepaired DNA damage is seen as chromatid breaks, deletions, fragments and exchanges.

  20. Cadmium carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Waalkes, Michael P

    2003-12-10

    Cadmium is a heavy metal of considerable environmental and occupational concern. Cadmium compounds are classified as human carcinogens by several regulatory agencies. The most convincing data that cadmium is carcinogenic in humans comes from studies indicating occupational cadmium exposure is associated with lung cancer. Cadmium exposure has also been linked to human prostate and renal cancer, although this linkage is weaker than for lung cancer. Other target sites of cadmium carcinogenesis in humans, such as liver, pancreas and stomach, are considered equivocal. In animals, cadmium effectively induces cancers at multiple sites and by various routes. Cadmium inhalation in rats induces pulmonary adenocarcinomas, in accord with its role in human lung cancer. Cadmium can induce tumors and/or preneoplastic lesions within the rat prostate after ingestion or injection. At relatively high doses, cadmium induces benign testicular tumors in rats, but these appear to be due to early toxic lesions and loss of testicular function, rather than from a specific carcinogenic effect of cadmium. Like many other metals, cadmium salts will induce mesenchymal tumors at the site of subcutaneous (s.c.) or intramuscular (i.m.) injections, but the human relevance of these is dubious. Other targets of cadmium in rodents include the liver, adrenal, pancreas, pituitary, and hematopoietic system. With the exception of testicular tumors in rodents, the mechanisms of cadmium carcinogenesis are poorly defined. Cadmium can cause any number of molecular lesions that would be relevant to oncogenesis in various cellular model systems. Most studies indicate cadmium is poorly mutagenic and probably acts through indirect or epigenetic mechanisms, potentially including aberrant activation of oncogenes and suppression of apoptosis.

  1. Cadmium carcinogenesis

    International Nuclear Information System (INIS)

    Cadmium is a heavy metal of considerable environmental and occupational concern. Cadmium compounds are classified as human carcinogens by several regulatory agencies. The most convincing data that cadmium is carcinogenic in humans comes from studies indicating occupational cadmium exposure is associated with lung cancer. Cadmium exposure has also been linked to human prostate and renal cancer, although this linkage is weaker than for lung cancer. Other target sites of cadmium carcinogenesis in humans, such as liver, pancreas and stomach, are considered equivocal. In animals, cadmium effectively induces cancers at multiple sites and by various routes. Cadmium inhalation in rats induces pulmonary adenocarcinomas, in accord with its role in human lung cancer. Cadmium can induce tumors and/or preneoplastic lesions within the rat prostate after ingestion or injection. At relatively high doses, cadmium induces benign testicular tumors in rats, but these appear to be due to early toxic lesions and loss of testicular function, rather than from a specific carcinogenic effect of cadmium. Like many other metals, cadmium salts will induce mesenchymal tumors at the site of subcutaneous (s.c.) or intramuscular (i.m.) injections, but the human relevance of these is dubious. Other targets of cadmium in rodents include the liver, adrenal, pancreas, pituitary, and hematopoietic system. With the exception of testicular tumors in rodents, the mechanisms of cadmium carcinogenesis are poorly defined. Cadmium can cause any number of molecular lesions that would be relevant to oncogenesis in various cellular model systems. Most studies indicate cadmium is poorly mutagenic and probably acts through indirect or epigenetic mechanisms, potentially including aberrant activation of oncogenes and suppression of apoptosis

  2. Light management in thin-film silicon solar cells

    OpenAIRE

    Isabella, O.

    2013-01-01

    Solar energy can fulfil mankind’s energy needs and secure a more balanced distribution of primary sources of energy. Wafer-based and thin-film silicon solar cells dominate todays’ photovoltaic market because silicon is a non-toxic and abundant material and high conversion efficiencies are achieved with silicon-based solar cells. To stay competitive with bulk crystalline silicon and other thin-film solar cell technologies, thin-film silicon solar cells have to achieve a conversion efficiency l...

  3. Thin Films of Gallium Arsenide and Gallium Aluminum Arsenide by Metalorganic Chemical Vapor Deposition.

    Science.gov (United States)

    Look, Edward Gene Lun

    Low pressure metalorganic chemical vapor deposition (LPMOCVD) of thin films of gallium arsenide (GaAs) and gallium aluminum arsenide (GaAlAs) was performed in a horizontal cold wall chemical vapor deposition (CVD) reactor. The organometallic (group III) sources were triethylgallium (TEGa) and triethylaluminum (TEAl), used in conjunction with arsine (AsH_3) as the group V source. It was found that growth parameters such as growth temperature, pressure, source flow rates and temperatures have a profound effect on the film quality and composition. Depending on the particular combination of conditions, both the surface and overall morphologies may be affected. The films were nondestructively analyzed by Raman and photoreflectance spectroscopies, x-ray diffraction and rocking curve studies, scanning electron microscopy, energy dispersive spectroscopy, Hall measurements and film thicknesses were determined with a step profilometer.

  4. Optimization of High-Efficiency CdS/CdTe Thin Film Solar Cell Using Step Doping Grading and Thickness of the Absorption Layer

    Directory of Open Access Journals (Sweden)

    Masoud Sabaghi

    2015-06-01

    Full Text Available In this paper, the influence of stepped doping of the absorber layer on performance of Cadmium Sulfide/Cadmium Telluride (CdS/CdTe solar cell has been investigated. At first, the electrical characteristics of conventional CdS/CdTe solar cell is validated with fabricated CdS/CdTe solar cell. To improve the maximum efficiency of CdS/CdTe solar cell, the doping and thickness of the absorption layer are optimized. By step doping concentration within the absorber layer using buffer layer back contact and the increase in stepping gradient of the doping of CdTe layer, improved the conversion efficiency about 2.4% were obtained. The open-circuit voltage, short-circuit current density, fill factor and total area conversion efficiency of optimized solar cell structure are 952 mV, 25.97 mA/cm2, 78.5% and 18.7% under global AM 1.5 conditions, respectively.

  5. 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.

  6. A Microstrip Printed Dipole Solar Antenna Using Polycrystalline Silicon Solar Cells

    OpenAIRE

    Shynu, S.; Roo Ons, Maria; Ruvio, Giuseppe; Ammann, Max; MCCORMACK, SARAH; Norton, Brian

    2008-01-01

    A novel printed dipole solar antenna design with an integrated balun is proposed for the first time with high efficiency polycrystalline silicon solar cells is presented in this paper. The optimum orientation of the silver DC bus bars of the solar cell is determined in order to achieve best antenna performance. Good solar antenna performance similar to that of ordinary printed dipoles with PEC reflectors is achieved.

  7. Manufacture and testing of a solar panel assembly comprising bifacial solar cells (AMOC-SPA)

    Science.gov (United States)

    Hoffmann, Uwe; Koch, Juergen W.

    1989-08-01

    The concept, manufacture and testing of the Solar Panel Assembly (SPA) are described. Bifacial solar cells, flexible harness, striped substrates and blanket integrated cushioning are all features of this solar panel. The SPA is designed to be modular. The power output, for an operating voltage of 7.2 V, was approximately 100 W for 192 5 cm by 5 cm solar cells, each under front and rear side illumination. Results of further tests and of a flight acceptance test are presented.

  8. Electricity from photovoltaic solar cells: Flat-Plate Solar Array Project final report. Volume IV: High-efficiency solar cells

    OpenAIRE

    Leipold, M.; L. Cheng; Daud, T.; Mokashi, A; Burger, D.

    1986-01-01

    The Flat-Plate Solar Array (FSA) Project, funded by the U.S. Government and managed by the Jet Propulsion Laboratory, was formed in 1975 to develop the module/array technology needed to attain widespread terrestrial use of photovoltaics by 1985. To accomplish this, the FSA Project established and managed an Industry, University, and Federal Government Team to perform the needed research and development (R&D). The High-Efficiency Solar Cells Task was assigned the objective of understandin...

  9. Uptake and egress of cadmium in cultures of cadmium-resistant and the corresponding ''wild-type'' cells

    International Nuclear Information System (INIS)

    Development of resistance against the highly toxic Cd++ ion has been described earlier both in animals, cell cultures and in bacteria. In this paper we have tested if decreased intracellular concentration of Cd plays a role in resistance to Cd in three mammalian cell cultures. The cells originated from different tissue and from two different species, Cd-resistant and corresponding ''wild-type'' strains were used. The results from all three lines show essentially the same, namely that there is no significant difference in Cd content between the Cd-resistant and the non-resistant cells. The resistant cells from all three lines grow continuously with a cellular Cd-content which is several times higher than that killing all cells of the non-resistant ''wild-type''. (author)

  10. 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. PMID:26615488

  11. Photocurrent images of amorphous-silicon solar-cell modules

    Science.gov (United States)

    Kim, Q.; Shumka, A.; Trask, J.

    1985-01-01

    Results obtained in applying the unique characteristics of the solar cell laser scanner to investigate the defects and quality of amorphous silicon cells are presented. It is concluded that solar cell laser scanners can be effectively used to nondestructively test not only active defects but also the cell quality and integrity of electrical contacts.

  12. The stress response of human proximal tubule cells to cadmium involves up-regulation of haemoxygenase 1 and metallothionein but not cytochrome P450 enzymes.

    Science.gov (United States)

    Boonprasert, Kanyarat; Satarug, Soisungwan; Morais, Christudas; Gobe, Glenda C; Johnson, David W; Na-Bangchang, Kesara; Vesey, David A

    2016-05-13

    Enzymes of the cytochrome P450 (CYP) super-family are implicated in cadmium (Cd) -induced nephrotoxicity, however, direct evidence is lacking. This study investigated the endogenous expression of various CYP proteins together with the stress-response proteins, heme oxygenase-1 (HO-1) and metallothionein (MT) in human kidney sections and in cadmium-exposed primary cultures of human proximal tubular epithelial cells (PTC). By immunohistochemistry, the CYP members 2B6, 4A11 and 4F2 were prominently expressed in the cortical proximal tubular cells and to a lesser extent in distal tubular cells. Low levels of CYPs 2E1 and 3A4 were also detected. In PTC, in the absence of Cd, CYP2E1, CYP3A4, CYP4F2 and MT were expressed, but HO-1, CYP2B6 and CYP4A11 were not detected. A range of cadmium concentrations (0-100μM) were utilized to induce stress conditions. MT protein was further induced by as little as 0.5μM cadmium, reaching a 6-fold induction at 20μM, whereas for HO-1, a 5μM cadmium concentration was required for initial induction and at 20μM cadmium reached a 15-fold induction. The expression of CYP2E1, CYP3A4, and CYP4F2 were not altered by any cadmium concentrations tested at 48h. Cadmium caused a reduction in cell viability at concentrations above 10μM. In conclusion although cultured PTC, do express CYP proteins, (CYP2E1, CYP3A4, and CYP4F2), Cd-induced cell stress as indicted by induction of HO-1 and MT does not alter expression of these CYP proteins at 48h. PMID:27005776

  13. MANUFACTURE OF PHOTOVOLTAIC SOLAR CELL USING PLANT CHLOROPHYLL

    Science.gov (United States)

    To date, we have successfully manufactured working chlorophyll sensitized solar cells using chlorophyll (and b mixture) from spinach leaves. We have evaluated the electronic characteristics (voltage, current, and power outputs using different loading resistors) of this solar c...

  14. Inverted amorphous silicon solar cell utilizing cermet layers

    Science.gov (United States)

    Hanak, Joseph J.

    1979-01-01

    An amorphous silicon solar cell incorporating a transparent high work function metal cermet incident to solar radiation and a thick film cermet contacting the amorphous silicon opposite to said incident surface.

  15. Enhanced cadmium cytotoxicity in A549 cells with reduced glutathione levels is due to neither enhanced cadmium accumulation nor reduced metallothionein synthesis

    International Nuclear Information System (INIS)

    Glutathione (GSH) depletion sensitizes human lung carcinoma (A549-T27) cells to the cytotoxic effects of Cd++. The effects of GSH depletion on Cd++ accumulation and Cd++-induced metallothionein (MT) content were investigated to determine the possible role of these Cd++ responses in the sensitization process. Cellular GSH was depleted to 20% to 25% of control levels with buthionine sulfoximine (BSO), or diethyl maleate (DEM), respectively. Neither treatment significantly affected Cd++-induced accumulation of exogenous 35s-cysteine into intracellular MT in a dose-dependent fashion. The results indicate that neither enhanced Cd++ accumulation nor reduced MT synthesis plays a primary role in affecting enhanced Cd++ cytotoxicity in A549 cells with reduced GSH levels. Although BSO inhibition of GSH synthesis enhanced MT synthesis, it sensitized the cells to Cd++, which suggests an additive effect of GSH and MT in cadmium cytoprotection. This observation also raises the possibility that intracellular cysteine levels limit Cd++-induced MT accumulation rates

  16. Noble Metal Arsenides and Gold Inclusions in Northwest Africa 8186

    Science.gov (United States)

    Srinivasan, P.; Agee, C. B.; McCubbin, F. M.; Rahman, Z.; Keller, L. P.

    2016-01-01

    CK carbonaceous chondrites are a highly thermally altered group of carbonaceous chondrites, experiencing temperatures ranging between approx.576-867 C. Additionally, the mineralogy of the CK chondrites record the highest overall oxygen fugacity of all chondrites, above the fayalite-magnetite-quartz (FMQ) buffer. Metallic Fe-Ni is extremely rare in CK chondrites, but magnetite and Fe,Ni sulfides are commonly observed. Noble metal-rich inclusions have previously been found in some magnetite and sulfide grains. These arsenides, tellurides, and sulfides, which contain varying amounts of Pt, Ru, Os, Te, As, Ir, and S, are thought to form either by condensation from a solar gas, or by exsolution during metamorphism on the chondritic parent body. Northwest Africa (NWA) 8186 is a highly metamorphosed CK chondrite. This meteorite is predominately composed of NiO-rich forsteritic olivine (Fo65), with lesser amounts of plagioclase (An52), augite (Fs11Wo49), magnetite (with exsolved titanomagnetite, hercynite, and titanohematite), monosulfide solid solution (with exsolved pentlandite), and the phosphate minerals Cl-apatite and merrillite. This meteorite contains coarse-grained, homogeneous silicates, and has 120deg triple junctions between mineral phases, which indicates a high degree of thermal metamorphism. The presence of NiO-rich olivine, oxides phases all bearing Fe3+, and the absence of metal, are consistent with an oxygen fugacity above the FMQ buffer. We also observed noble metal-rich phases within sulfide grains in NWA 8186, which are the primary focus of the present study.

  17. Thin-film silicon solar cell technology

    Energy Technology Data Exchange (ETDEWEB)

    Shah, A.V.; Meier, J.; Kroll, U.; Droz, C.; Bailat, J. [University of Neuchatel (Switzerland). Inst. of Microtechnology; Schade, H. [RWE Schott Solar GmbH, Putzbrunn (Germany); Vanecek, M. [Academy of Sciences, Prague (Czech Republic). Inst. of Physics; Vallat Sauvain, E.; Wyrsch, N. [University of Neuchatel (Switzerland). Inst. of Microtechnology; Unaxis SPTec S A, Neuchatel (Switzerland)

    2004-07-01

    This paper describes the use, within p-i-n- and n-i-p-type solar cells, of hydrogenated amorphous silicon (a-Si:H) and hydrogenated microcrystalline silicon ({mu}c-Si:H) thin films (layers), both deposited at low temperatures (200{sup o}C) by plasma-assisted chemical vapour deposition (PECVD), from a mixture of silane and hydrogen. Optical and electrical properties of the i-layers are described. These properties are linked to the microstructure and hence to the i-layer deposition rate, that in turn, affects throughput in production. The importance of contact and reflection layers in achieving low electrical and optical losses is explained, particularly for the superstrate case. Especially the required properties for the transparent conductive oxide (TCO) need to be well balanced in order to provide, at the same time, for high electrical conductivity (preferably by high electron mobility), low optical absorption and surface texture (for low optical losses and pronounced light trapping). Single-junction amorphous and microcrystalline p-i-n-type solar cells, as fabricated so far, are compared in their key parameters (J{sub sc},FF,V{sub oc}) with the [theoretical] limiting values. Tandem and multijunction cells are introduced; the {mu}c-Si: H/a-Si: H or [micromorph] tandem solar cell concept is explained in detail, and recent results obtained here are listed and commented. Factors governing the mass-production of thin-film silicon modules are determined both by inherent technical reasons, described in detail, and by economic considerations. The cumulative effect of these factors results in distinct efficiency reductions from values of record laboratory cells to statistical averages of production modules. Finally, applications of thin-film silicon PV modules, especially in building-integrated PV (BIPV) are shown. In this context, the energy yields of thin-film silicon modules emerge as a valuable gauge for module performance, and compare very favourably with those of

  18. 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. PMID:26467054

  19. 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%.

  20. Solution-processed solar cells based on environmentally friendly AgBiS2 nanocrystals

    Science.gov (United States)

    Bernechea, María; Miller, Nichole Cates; Xercavins, Guillem; So, David; Stavrinadis, Alexandros; Konstantatos, Gerasimos

    2016-08-01

    Solution-processed inorganic solar cells are a promising low-cost alternative to first-generation solar cells. Solution processing at low temperatures combined with the use of non-toxic and abundant elements can help minimize fabrication costs and facilitate regulatory acceptance. However, at present, there is no material that exhibits all these features while demonstrating promising efficiencies. Many of the candidates being explored contain toxic elements such as lead or cadmium (perovskites, PbS, CdTe and CdS(Se)) or scarce elements such as tellurium or indium (CdTe and CIGS(Se)/CIS). Others require high-temperature processes such as selenization or sintering, or rely on vacuum deposition techniques (Sb2S(Se)3, SnS and CZTS(Se)). Here, we present AgBiS2 nanocrystals as a non-toxic, earth-abundant material for high-performance, solution-processed solar cells fabricated under ambient conditions at low temperatures (≤100 °C). We demonstrate devices with a certified power conversion efficiency of 6.3%, with no hysteresis and a short-circuit current density of ∼22 mA cm‑2 for an active layer thickness of only ∼35 nm.

  1. 13.4% efficient thin-film CdS/CdTe solar cells

    Science.gov (United States)

    Chu, T. L.; Chu, S. S.; Ferekides, C.; Wu, C. Q.; Britt, J.; Wang, C.

    1991-12-01

    Cadmium telluride is a promising thin-film photovoltaic material as shown by the more than 10% efficient CdS/CdTe heterojunction solar cells. In this work, thin-film CdS/CdTe solar cells have been prepared using CdS films grown from an aqueous solution and p-CdTe films deposited by close-spaced sublimation (CSS). The properties of CdS films deposited from an ammonical solution of a Cd-salt, an ammonium salt, and thiourea have been controlled by optimizing the temperature and composition of the solution. The solution-grown CdS films have a high photoconductivity ratio, and its optical transmission is superior to that of vacuum evaporated CdS films. The properties of p-CdTe films deposited by CSS have been optimized by controlling the temperature and composition of the source material, and the substrate temperature. The properties of CdS/CdTe heterojunctions have been studied; junction photovoltage spectroscopy is used for the qualitative comparison of junction characteristics. Solar cells of 1-cm2 area with an AM 1.5 efficiency of 13.4% are reported.

  2. 13. 4% efficient thin-film CdS/CdTe solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Chu, T.L.; Chu, S.S.; Ferekides, C.; Wu, C.Q.; Britt, J.; Wang, C. (Department of Electrical Engineering, University of South Florida, Tampa, Florida (USA))

    1991-12-15

    Cadmium telluride is a promising thin-film photovoltaic material as shown by the more than 10% efficient CdS/CdTe heterojunction solar cells. In this work, thin-film CdS/CdTe solar cells have been prepared using CdS films grown from an aqueous solution and {ital p}-CdTe films deposited by close-spaced sublimation (CSS). The properties of CdS films deposited from an ammonical solution of a Cd-salt, an ammonium salt, and thiourea have been controlled by optimizing the temperature and composition of the solution. The solution-grown CdS films have a high photoconductivity ratio, and its optical transmission is superior to that of vacuum evaporated CdS films. The properties of {ital p}-CdTe films deposited by CSS have been optimized by controlling the temperature and composition of the source material, and the substrate temperature. The properties of CdS/CdTe heterojunctions have been studied; junction photovoltage spectroscopy is used for the qualitative comparison of junction characteristics. Solar cells of 1-cm{sup 2} area with an AM 1.5 efficiency of 13.4% are reported.

  3. IN VITRO INHIBITION OF ACETYLCHOLINESTERASE ACTIVITY IN HUMAN RED BLOOD CELLS BY CADMIUM AND LEAD

    Directory of Open Access Journals (Sweden)

    M. Abdollahi

    1998-08-01

    Full Text Available The effects of cadmium and lead on human erythrocyte acetylcholinesterase activity were studied. Blood used in this study was obtained from 24 healthy individuals, then after hemolysation, treated with 3 various concentrations of cadmium and lead. A strong inhibition of acetylcholinesterase was noted in treated samples by cadmium and lead. The remaining activity In the case of lead, the remaining activity was found to be 81% with the highest concentration , S7% with the middle and 94% with the lowest one (30 fi g/dl, p<0.05. Cadmium showed a nearly linear correlation between doses used and decrease in activity (r- = 0.S3, lead showed a better correlation (r- = 0.92. The direct effect of metal ions on AChE, i.e. a decrease in quantity of the enzyme, may be a proposed mechanism for this depression.

  4. Correcting For Capacitance In Tests Of Solar Cells

    Science.gov (United States)

    Mueller, Robert L.

    1995-01-01

    Modified procedure for testing solar photovoltaic cells and modified software for processing test data provide corrections for effects of cell capacitance. Procedure and software needed because (a) some photovoltaic devices (for example, silicon solar cells with back-surface field region) store minority charge carriers in cell junction and thus exhibit significant capacitance, (b) capacitance affects current-vs.-voltage (I-V) measurements made when transient load connected to cell, and (c) transient load used in unmodified version of test procedure. Corrected I-V curve obtained in test of solar cell according to modified procedure approximates true cell voltage vs. cell current more closely.

  5. Simulation of an electrowetting solar concentration cell

    Science.gov (United States)

    Khan, Iftekhar; Rosengarten, Gary

    2015-09-01

    Electrowetting control of liquid lenses has emerged as a novel approach for solar tracking and concentration. Recent studies have demonstrated the concept of steering sunlight using thin electrowetting cells without the use of any bulky mechanical equipment. Effective application of this technique may facilitate designing thin and flat solar concentrators. Understanding the behavior of liquid-liquid and liquid-solid interface of the electrowetting cell through trial and error experimental processes is not efficient and is time consuming. In this paper, we present a simulation model to predict the liquid-liquid and liquid-solid interface behavior of electrowetting cell as a function of various parameters such as applied voltage, dielectric constant, cell size etc. We used Comsol Multiphysics simulations incorporating experimental data of different liquids. We have designed both two dimensional and three dimensional simulation models, which predict the shape of the liquid lenses. The model calculates the contact angle using the Young-Lippman equation and uses a moving mesh interface to solve the Navier-stokes equation with Navier slip wall boundary condition. Simulation of the electric field from the electrodes is coupled to the Young-Lippman equation. The model can also be used to determine operational characteristics of other MEMS electrowetting devices such as electrowetting display, optical switches, electronic paper, electrowetting Fresnel lens etc.

  6. A terminal molybdenum arsenide complex synthesized from yellow arsenic.

    Science.gov (United States)

    Curley, John J; Piro, Nicholas A; Cummins, Christopher C

    2009-10-19

    A terminal molybdenum arsenide complex is synthesized in one step from the reactive As(4) molecule. The properties of this complex with its arsenic atom ligand are discussed in relation to the analogous nitride and phosphide complexes. PMID:19764796

  7. OPTEC: A Cubesat for Solar Cell Calibration

    Science.gov (United States)

    Landis, Geoffrey; Hepp, Aloysius; Arutyunov, Dennis; White, Kelsey; Witsberger, Paul

    2014-01-01

    A new type of small spacecraft, the cubesat, has introduced a new concept for extremely small, low-cost missions into space. Cubesats are designed to be launched as secondary payloads on other missions, and are made up of unit elements (U) of size 10 cm by 10 cm by 10 cm, with a nominal mass of no more than 1.33 kg per U. We have designed a cubesat, OPTEC (Orbital Photovoltaic Testbed Cubesat) as a low-cost testbed to demonstrate, calibrate, and test solar cell technologies in space. Size of the cubesat is 2U (10x10x20cm, and the mass 2.66 kg. The cubesat deploys from the International Space Station into Low Earth Orbit at an altitude of about 420 km. Up to two 4x8cm test solar panels can be flown, with full I-V curves and temperature measurements taken.

  8. Applications of Laser Precisely Processing Technology in Solar Cells

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    According to the design method of laser resonator cavity, we optimized the primary parameters of resonator and utilized LD arrays symmetrically pumping manner to implementing output of the high-brightness laser in our laser cutter, then which was applied to precisely cutting the conductive film of CuInSe2 solar cells, the buried contact silicon solar cells' electrode groove, and perforating in wafer which is used to the emitter wrap through silicon solar cells. Laser processing precision was less than 40μm, the results have met solar cell's fabrication technology, and made finally the buried cells' conversion efficiency be improved from 18% to 21% .

  9. Photovoltaic characteristics of porous silicon /(n+ - p) silicon solar cells

    International Nuclear Information System (INIS)

    Full text : The purpose of this work is to improve the photovoltaic parameters of the screen-printed silicon solar cells by formation the nano-porous silicon film on the frontal surface of the cell. The photovoltaic characteristics of two type silicon solar cells with and without porous silicon layer were measured and compared. A remarkable increment of short-circuit current density and the efficiency by 48 percent and 20 percent, respectively, have been achieved for PS/(n+ - pSi) solar cell comparing to (n+ - p)Si solar cell without PS layer

  10. In vitro evaluation of cell death induced by cadmium, lead and their binary mixtures on erythrocytes of Common buzzard (Buteo buteo).

    Science.gov (United States)

    Hernández-García, A; Romero, D; Gómez-Ramírez, P; María-Mojica, P; Martínez-López, E; García-Fernández, A J

    2014-03-01

    Cadmium and lead are persistent and ubiquitous metals that can cause several deleterious effects in living beings. Apoptosis and necrosis are two types of cell death that can be found after in vivo and in vitro exposure to these metals. In this study, isolated red blood cells from living captive Common buzzard (Buteo buteo) were exposed in vitro to different concentrations of lead, cadmium, and the mixture lead-cadmium in a proportion of 1:10 (similar to that found in previous field studies). Data obtained from dose-response curves were used to evaluate the interactive effects of metal mixtures on cell viability. In general, except for the exposure to NOEC, additivity was the most frequently observed response. As described in human, after in vitro exposure, lead was highly accumulated in buzzard erythrocytes, while cadmium accumulation was scarce. Finally, the type of cell death (apoptosis or necrosis) induced by the exposure to different concentrations of these heavy metals and their mixtures was evaluated in the red blood cells. Apoptosis was found to be the main type of cell death observed after cadmium and/or lead exposure. However, this exposure caused an increase in lysis or necrosis, especially if red blood cells were exposed to high doses. PMID:24287112

  11. High efficiency solar cells combining a perovskite and a silicon heterojunction solar cells via an optical splitting system

    Energy Technology Data Exchange (ETDEWEB)

    Uzu, Hisashi, E-mail: Hisashi.Uzu@kaneka.co.jp, E-mail: npark@skku.edu; Ichikawa, Mitsuru; Hino, Masashi; Nakano, Kunihiro; Meguro, Tomomi; Yamamoto, Kenji [Kaneka Corporation, 5-1-1, Torikai-Nishi, Settsu, Osaka 566-0072 (Japan); Hernández, José Luis [Kaneka Belgium N.V., Nijverheidsstraat 16, 2260 Westerlo-Oevel (Belgium); Kim, Hui-Seon; Park, Nam-Gyu, E-mail: Hisashi.Uzu@kaneka.co.jp, E-mail: npark@skku.edu [School of Chemical Engineering and Department of Energy Science, Sungkyunkwan University, 300 Cheoncheon-dong, Jangan-gu, Suwon 440-746 (Korea, Republic of)

    2015-01-05

    We have applied an optical splitting system in order to achieve very high conversion efficiency for a full spectrum multi-junction solar cell. This system consists of multiple solar cells with different band gap optically coupled via an “optical splitter.” An optical splitter is a multi-layered beam splitter with very high reflection in the shorter-wave-length range and very high transmission in the longer-wave-length range. By splitting the incident solar spectrum and distributing it to each solar cell, the solar energy can be managed more efficiently. We have fabricated optical splitters and used them with a wide-gap amorphous silicon (a-Si) solar cell or a CH{sub 3}NH{sub 3}PbI{sub 3} perovskite solar cell as top cells, combined with mono-crystalline silicon heterojunction (HJ) solar cells as bottom cells. We have achieved with a 550 nm cutoff splitter an active area conversion efficiency of over 25% using a-Si and HJ solar cells and 28% using perovskite and HJ solar cells.

  12. High efficiency solar cells combining a perovskite and a silicon heterojunction solar cells via an optical splitting system

    International Nuclear Information System (INIS)

    We have applied an optical splitting system in order to achieve very high conversion efficiency for a full spectrum multi-junction solar cell. This system consists of multiple solar cells with different band gap optically coupled via an “optical splitter.” An optical splitter is a multi-layered beam splitter with very high reflection in the shorter-wave-length range and very high transmission in the longer-wave-length range. By splitting the incident solar spectrum and distributing it to each solar cell, the solar energy can be managed more efficiently. We have fabricated optical splitters and used them with a wide-gap amorphous silicon (a-Si) solar cell or a CH3NH3PbI3 perovskite solar cell as top cells, combined with mono-crystalline silicon heterojunction (HJ) solar cells as bottom cells. We have achieved with a 550 nm cutoff splitter an active area conversion efficiency of over 25% using a-Si and HJ solar cells and 28% using perovskite and HJ solar cells

  13. 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

  14. Intraspecific variability of cadmium tolerance and accumulation, and cadmium-induced cell wall modifications in the metal hyperaccumulator Arabidopsis halleri.

    Science.gov (United States)

    Meyer, Claire-Lise; Juraniec, Michal; Huguet, Stéphanie; Chaves-Rodriguez, Elena; Salis, Pietro; Isaure, Marie-Pierre; Goormaghtigh, Erik; Verbruggen, Nathalie

    2015-06-01

    Certain molecular mechanisms of Cd tolerance and accumulation have been identified in the model species Arabidopsis halleri, while intraspecific variability of these traits and the mechanisms of shoot detoxification were little addressed. The Cd tolerance and accumulation of metallicolous and non-metallicolous A. halleri populations from different genetic units were tested in controlled conditions. In addition, changes in shoot cell wall composition were investigated using Fourier transform infrared spectroscopy. Indeed, recent works on A. halleri suggest Cd sequestration both inside cells and in the cell wall/apoplast. All A. halleri populations tested were hypertolerant to Cd, and the metallicolous populations were on average the most tolerant. Accumulation was highly variable between and within populations, and populations that were non-accumulators of Cd were identified. The effect of Cd on the cell wall composition was quite similar in the sensitive species A. lyrata and in A. halleri individuals; the pectin/polysaccharide content of cell walls seems to increase after Cd treatment. Nevertheless, the changes induced by Cd were more pronounced in the less tolerant individuals, leading to a correlation between the level of tolerance and the extent of modifications. This work demonstrated that Cd tolerance and accumulation are highly variable traits in A. halleri, suggesting adaptation at the local scale and involvement of various molecular mechanisms. While in non-metallicolous populations drastic modifications of the cell wall occur due to higher Cd toxicity and/or Cd immobilization in this compartment, the increased tolerance of metallicolous populations probably involves other mechanisms such as vacuolar sequestration. PMID:25873677

  15. TJ Solar Cell GaInP/GaAs/Ge Ultrahigh-Efficiency Solar Cells

    International Nuclear Information System (INIS)

    This talk will discuss recent developments in III-V multijunction photovoltaic technology which have led to the highest-efficiency solar cells ever demonstrated. The relationship between the materials science of III-V semiconductors and the achievement of record solar cell efficiencies will be emphasized. For instance, epitaxially-grown GAInP has been found to form a spontaneously-ordered GaP/InP (111) superlattice. This ordering affects the band gap of the material, which in turn affects the design of solar cells which incorporate GaInP. For the next generation of ultrahigh-efficiency III-V solar cells, we need a new semiconductor which is lattice-matched to GaAs, has a band gap of 1 eV, and has long minority-carrier diffusion lengths. Out of a number of candidate materials, the recently-discovered alloy GaInNAs appears to have the greatest promise. This material satisfies the first two criteria, but has to date shown very low diffusion lengths, a problem which is our current focus in the development of these next-generation cells.

  16. Simulation of the Mars Surface Solar Spectra for Optimized Performance of Triple-Junction Solar Cells

    Science.gov (United States)

    Edmondson, Kenneth M.; Joslin, David E.; Fetzer, Chris M.; King, RIchard R.; Karam, Nasser H.; Mardesich, Nick; Stella, Paul M.; Rapp, Donald; Mueller, Robert

    2007-01-01

    The unparalleled success of the Mars Exploration Rovers (MER) powered by GaInP/GaAs/Ge triple-junction solar cells has demonstrated a lifetime for the rovers that exceeded the baseline mission duration by more than a factor of five. This provides confidence in future longer-term solar powered missions on the surface of Mars. However, the solar cells used on the rovers are not optimized for the Mars surface solar spectrum, which is attenuated at shorter wavelengths due to scattering by the dusty atmosphere. The difference between the Mars surface spectrum and the AM0 spectrum increases with solar zenith angle and optical depth. The recent results of a program between JPL and Spectrolab to optimize GaInP/GaAs/Ge solar cells for Mars are presented. Initial characterization focuses on the solar spectrum at 60-degrees zenith angle at an optical depth of 0.5. The 60-degree spectrum is reduced to 1/6 of the AM0 intensity and is further reduced in the blue portion of the spectrum. JPL has modeled the Mars surface solar spectra, modified an X-25 solar simulator, and completed testing of Mars-optimized solar cells previously developed by Spectrolab with the modified X-25 solar simulator. Spectrolab has focused on the optimization of the higher efficiency Ultra Triple-Junction (UTJ) solar cell for Mars. The attenuated blue portion of the spectrum requires the modification of the top sub-cell in the GaInP/GaAs/Ge solar cell for improved current balancing in the triple-junction cell. Initial characterization confirms the predicted increase in power and current matched operation for the Mars surface 60-degree zenith angle solar spectrum.

  17. Solar cells: An environment-benign energy source?

    International Nuclear Information System (INIS)

    Attention is paid to a study on the environmental aspects of solar cell production techniques and the possibility of recycling solar cell materials. In the study the following types of solar cell modules are dealt with: CdTe and CuInSe2, amorphous silicon, crystalline silicon, and GaAs. It appears that silicon solar cells have minor environmental effects and are controllable. However, attention should be paid to the energy consumption and the use of etching and purification materials during the production of solar cells, and the emission of heavy metals from f.e. CdTe/CIS solar cells during and after usage. Without effective recycling enough supplies of indium, selenium and tellurium cannot be guaranteed. 3 figs., 1 ill

  18. Characterization of Thin Films for Polymer Solar Cells

    DEFF Research Database (Denmark)

    Tromholt, Thomas

    The field of polymer solar cells has undergone an extensive development in recent years after the invention of semiconducting polymers in 1991. Efficiencies have gradually increased to above 10 %, and high throughput processing methods such as roll-to-roll coating allow for production of thousands...... of solar cells with low embedded time, material, and energy consumption as compared to silicon solar cells. Consequently, different demonstration products of small mobile gadgets based on polymer solar cells have been produced, which are fully competitive with conventional energy technologies......, illustrating the maturity of the technology. However, a limiting factor in terms of full commercialization is the stability of polymer solar cells. While is has been estimated that 10 years lifetime is needed, existing technologies only provide stabilities up to 1 year. Degradation of polymer solar cell is a...

  19. Progress in batteries and solar cells. Volume 5

    International Nuclear Information System (INIS)

    The 89 articles in this book are on research in batteries, solar cells and fuel cells. Topics include uses of batteries in electric powered vehicles, load management in power plants, batteries for miniature electronic devices, electrochemical processes, and various electrode and electrolyte materials, including organic compounds. Types of batteries discussed are lithium, lead-acid, manganese dioxide, Silver cells, Air cells, Nickel cells and solar cells. Problems of recharging and life cycle are also discussed

  20. 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