Sample records for photochemical solar cells

  1. Novel photochemical vapor deposition reactor for amorphous silicon solar cell deposition

    SciTech Connect

    Rocheleau, R.E.; Hegedus, S.S.; Buchanan, W.A.; Jackson, S.C.

    1987-07-13

    A novel photochemical vapor deposition (photo-CVD) reactor having a flexible ultraviolet-transparent Teflon curtain and a secondary gas flow to eliminate deposition on the window has been used to deposit amorphous silicon films and p-i-n solar cells. The background levels of atmospheric contaminants (H/sub 2/O, CO/sub 2/, N/sub 2/) depend strongly on the vacuum procedures but not on the presence of a Teflon curtain in the reactor. Intrinsic films with a midgap density of states of 3 x 10/sup 15/ eV/sup -1/ cm/sup -3/ and all-photo-CVD pin solar cells with efficiencies of 8.5% have been deposited.

  2. Photochemical solar cells based on dye-sensitization of nanocrystalline TiO{sub 2}

    SciTech Connect

    Deb, S.K.; Ferrere, S.; Frank, A.J.; Gregg, B.A.; Huang, S.Y.; Nozik, A.J.; Schlichthoerl, G.; Zaban, A. [National Renewable Energy Lab., Golden, CO (United States)

    1997-12-31

    A new type of photovoltaic cell is described. It is a photoelectrochemical device that is based on the dye-sensitization of thin (10--20 {micro}m) nanocrystalline films of TiO{sub 2} nanoparticles in contact with a non-aqueous liquid electrolyte. The cell is very simple to fabricate and, in principle, its color can be tuned through the visible spectrum, ranging from being completely transparent of black opaque by changing the absorption characteristics of the dye. The highest present efficiency of the dye-sensitized photochemical solar cell is about 11%. The cell has the potential to be a low-cost photovoltaic option. Unique applications include photovoltaic power windows and photoelectrochromic windows.

  3. Methods for the photochemical utilization of solar energy

    NASA Technical Reports Server (NTRS)

    Schwerzel, R. E.

    1978-01-01

    The paper considers the 'ground rules' which govern the efficiency of photochemical solar energy conversion and then summarizes the most promising approaches in each of three categories: photochemically assisted thermal systems for the heating and/or cooling of structures; photogalvanic systems for the production of electrical power in applications, such as photorechargeable batteries or inexpensive 'solar cells'; and photochemical formation of fuels for combustion and for use as chemical feedstocks or foods. Three concepts for the photochemical utilization of solar energy in space are found to be particularly promising: (1) photochemical trans-cis isomerization of indigold dyes for photoassisted heating or cooling, (2) the redox stabilized photoelectrolysis cell for the production of hydrogen (and/or oxygen or other useful chemicals), and (3) the liquid-junction photovoltaic cell for the production of electrical power.

  4. Photochemical solar cells based on dye-sensitization of nanocrystalline TiO2

    NASA Astrophysics Data System (ADS)

    Deb, S. K.; Ellingson, R.; Ferrere, S.; Frank, A. J.; Gregg, B. A.; Nozik, A. J.; Park, N.; Schlichthörl, G.; Zaban, A.

    1999-03-01

    A photoelectrochemical solar cell that is based on the dye-sensitization of thin nanocrystalline films of TiO2 (anatase) nanoparticles in contact with a non-aqueous liquid electrolyte is described. The cell, fabricated at NREL, shows a conversion efficiency of ˜9.2% at AM1.5, which approaches the best reported value of 10%-11% by Grätzel at EPFL in Lausanne, Switzerland. Femtosecond (fs) pump-probe spectroscopy has been used to time resolve the injection of electrons into the conduction band of nanocrystalline TiO2 films under ambient conditions following photoexcitation of the adsorbed Ru(II)-complex dye. The measurement indicates an instrument-limited -50 fs upper limit on the electron injection time. We also report the sensitization of nanocrystalline TiO2 by a novel iron-based dye. cis-[FeII(2,2'-bipyridine-4,4'-dicarboxylic acid)2(CN)2], a chromophore with an extremely short-lived, nonemissive excited state. The dye also exhibits a unique "band selective" sensitization through one of its two absorption bands. The operational principle of the device has been studied through the measurement of electric field distribution within the device structure and studies on the pH dependence of dye-redox potential. The incorporation of a WO3-based electrochromic layer into this device has led to a novel photoelectrochromic device structure for "smart window" applications.

  5. Photochemical aspects of solar energy conversion and storage

    Microsoft Academic Search

    J. R. Bolton

    1979-01-01

    The paper defines qualitatively and quantitatively the thermodynamic and kinetic limits on the photochemical conversion and storage of solar energy as it is received on the earth's surface. Attention is given to an evaluation of a number of possible reactions, with special emphasis on the generation of solar fuels such as hydrogen from water and the generation of electricity. The

  6. Photochemical solar cells based on d-band electrochemistry at transition metal diselenides. Technical progress report, second quarter, year one

    SciTech Connect

    Parkinson, B.A.; Furtak, T.E.

    1980-05-01

    Single crystals of the layered semiconductor tungsten diselenide have been grown by chemical vapor transport and evaluated as the photoanode in a n-WSe/sub 2//1M KI-0.1mI/sub 2//Pt photoelectrochemical cell. Progress is detailed. In situ topographic photogenerated carrier collection analysis with a scanning laser spot technique has verified that crystal edges exposed to the electrolyte are a major source of efficiency losses in the light to electrical energy conversion. Surface states due to edge sites have been detected with subband gap photocurrent spectroscopy and found to be located 0.2 eV below the conduction band edge. Several approaches have been demonstrated for the specific chemical treatment of the edge sites to reduce the effect of the surface states and increase the energy conversion efficiency. It was also found that iodine reduction (dark current) via these surface states is another factor in limiting cell efficiency.

  7. Photochemical conversion of solar energy in the environment. Book chapter

    SciTech Connect

    Zepp, R.G.

    1991-01-01

    Past research on photochemistry in the environment has focused on gas phase reactions in the atmosphere. Recently, however, environmentally significant photoreactions have been discovered in natural waters (i.e., the sea, lakes, and rivers), on soil surfaces, and in atmospheric condensed phases. These new investigations have been stimulated in part by interest in developing a scientific understanding of the role of photochemical processes in the biogeochemical cycles of various elements. In addition, other studies have explored the role of natural photochemical processes in cleansing the environemnt of various waste materials or, in some cases, in converting the wastes to more toxic substances. In the paper, current research results on the photochemical conversion of solar energy in aquatic environments and on soil and metal oxide surfaces are presented. Rate equations and products for selected homogeneous and heterogeneous photoreactions that occur in these systems are described. Data are presented for direct and sensitized photoreactions and for sunlight-initiated free radical reactions. (Copyright (c) 1991 Kluwer Academic Publishers.)

  8. Effects of solar ultraviolet radiation on photochemical efficiency of Chaetoceros curvisetus (Bacillariophyceae)

    Microsoft Academic Search

    W. C. Guan; P. Li; J. B. Jian; J. Y. Wang; S. H. Lu

    2011-01-01

    To assess the short- and long-term impacts of Ultraviolet radiation (UVR, 280–400 nm) on the red tide alga Chaetoceros curvisetus, we exposed cells to three different solar radiation treatments–PAB:280–700 nm, PA:320–700 nm, and P:400–700 nm under 20°C\\u000a incubated temperature. Short-term exposures were investigated: the photochemical efficiency (?PSII) versus irradiance curves under six levels of solar radiation by covering the incubators with a variable number

  9. Solar photochemical process engineering for production of fuels and chemicals

    NASA Technical Reports Server (NTRS)

    Biddle, J. R.; Peterson, D. B.; Fujita, T.

    1985-01-01

    The engineering costs and performance of a nominal 25,000 scmd (883,000 scfd) photochemical plant to produce dihydrogen from water were studied. Two systems were considered, one based on flat-plate collector/reactors and the other on linear parabolic troughs. Engineering subsystems were specified including the collector/reactor, support hardware, field transport piping, gas compression equipment, and balance-of-plant (BOP) items. Overall plant efficiencies of 10.3 and 11.6 percent are estimated for the flat-plate and trough systems, respectively, based on assumed solar photochemical efficiencies of 12.9 and 14.6 percent. Because of the opposing effects of concentration ratio and operating temperature on efficiency, it was concluded that reactor cooling would be necessary with the trough system. Both active and passive cooling methods were considered. Capital costs and energy costs, for both concentrating and non-concentrating systems, were determined and their sensitivity to efficiency and economic parameters were analyzed. The overall plant efficiency is the single most important factor in determining the cost of the fuel.

  10. Solar photochemical process engineering for production of fuels and chemicals

    NASA Technical Reports Server (NTRS)

    Biddle, J. R.; Peterson, D. B.; Fujita, T.

    1984-01-01

    The engineering costs and performance of a nominal 25,000 scmd (883,000 scfd) photochemical plant to produce dihydrogen from water were studied. Two systems were considered, one based on flat-plate collector/reactors and the other on linear parabolic troughs. Engineering subsystems were specified including the collector/reactor, support hardware, field transport piping, gas compression equipment, and balance-of-plant (BOP) items. Overall plant efficiencies of 10.3 and 11.6% are estimated for the flat-plate and trough systems, respectively, based on assumed solar photochemical efficiencies of 12.9 and 14.6%. Because of the opposing effects of concentration ratio and operating temperature on efficiency, it was concluded that reactor cooling would be necessary with the trough system. Both active and passive cooling methods were considered. Capital costs and energy costs, for both concentrating and non-concentrating systems, were determined and their sensitivity to efficiency and economic parameters were analyzed. The overall plant efficiency is the single most important factor in determining the cost of the fuel.

  11. Low-temperature Deposition of Hydrogenated Microcrystalline Silicon Thin Films by Photochemical Vapor Deposition Technique and Their Application to Thin Film Solar Cells

    Microsoft Academic Search

    Shuichi Hiza; Akira Yamada; Makoto Konagai

    2007-01-01

    Hydrogenated microcrystalline silicon (muc-Si:H) thin films were prepared by mercury-sensitized photochemical vapor deposition (photo-CVD) technique at various deposition temperatures. Crystalline volume fraction showed a monotonic decrease with increasing temperature from 125 to 200 °C caused by the enhanced desorption of surface hydrogen atoms. Since a similar decrease has been reported at higher temperatures than 400 °C in plasma-enhanced vapor deposition

  12. Solar Cells

    NASA Technical Reports Server (NTRS)

    1983-01-01

    The Heat Exchanger Method (HEM) produces high efficiency crystal ingots in an automated well-insulated furnace offering low equipment, labor and energy costs. The "grown" silicon crystals are used to make solar cells, or photovoltaic cells which convert sunlight directly into electricity. The HEM method is used by Crystal Systems, Inc. and was developed under a NASA/Jet Propulsion Laboratory contract. The square wafers which are the result of the process are sold to companies manufacturing solar panels.

  13. The photochemical effects of dynamically induced variations in solar insolation

    Microsoft Academic Search

    G. R. Sonnemann

    2001-01-01

    In this paper, the question of what happens when an air parcel in which photochemical processes take place moves around the earth with a certain velocity is considered. When the characteristic chemical system time corresponds to the rotation period of the earth (1 day) an influence of the diurnal variation of the chemical constituents on the zonal wind is found.

  14. High-temperature photochemical destruction of toxic organic wastes using concentrated solar radiation

    SciTech Connect

    Dellinger, B.; Graham, J.L.; Berman, J.M.; Taylor, P.H. [Dayton Univ., OH (United States)

    1994-05-01

    Application of concentrated solar energy has been proposed to be a viable waste disposal option. Specifically, this concept of solar induced high-temperature photochemistry is based on the synergistic contribution of concentrated infrared (IR) radiation, which acts as an intense heating source, and near ultraviolet and visible (UV-VIS) radiation, which can induce destructive photochemical processes. Some significant advances have been made in the theoretical framework of high-temperature photochemical processes (Section 2) and development of experimental techniques for their study (Section 3). Basic thermal/photolytic studies have addressed the effect of temperature on the photochemical destruction of pure compounds (Section 4). Detailed studies of the destruction of reaction by-products have been conducted on selected waste molecules (Section 5). Some very limited results are available on the destruction of mixtures (Section 6). Fundamental spectroscopic studies have been recently initiated (Section 7). The results to date have been used to conduct some relatively simple scale-up studies of the solar detoxification process. More recent work has focused on destruction of compounds that do not directly absorb solar radiation. Research efforts have focused on homogeneous as well as heterogeneous methods of initiating destructive reaction pathways (Section 9). Although many conclusions at this point must be considered tentative due to lack of basic research, a clearer picture of the overall process is emerging (Section 10). However, much research remains to be performed and most follow several veins, including photochemical, spectroscopic, combustion kinetic, and engineering scale-up (Section 11).

  15. Primary targets in photochemical inactivation of cells in culture

    NASA Astrophysics Data System (ADS)

    Berg, Kristian; Jones, Stuart G.; Prydz, Kristian; Moan, Johan

    1995-01-01

    The mechanisms of photoinactivation of NHIK 3025 cells in culture sensitized by tetrasulfonated phenylporphines (TPPS4) are described). Ultracentrifugation studies on postnuclear supernatants indicated that the intracellular distribution of TPPS4 resembles that of (beta) -N-acetyl-D-glucosaminidase ((beta) -AGA), a lysosomal marker enzyme, and that the cytosolic content of TPPS4 is below the detection limit of the ultracentrifugation method. Upon light exposure more than 90% of TPPS4 was lost from the lysosomal fractions, due to lysosomal rupture. The content of TPPS4 in the postnuclear supernatants was reduced by 30 - 40% upon exposure to light. This is most likely due to binding of TPPS4 to the nuclei, which were removed from the cell extracts before ultracentrifugation, after photochemical treatment. The unpolymerized form of tubulin seems to be an important target for the photochemical inactivation of NHIK 3025 cells. Since TPPS4 is mainly localized in lysosomes it was assumed that a dose of light disrupting a substantial number of lysosomes followed by microtubule depolymerization by nocodazole would enhance the sensitivity of the cells to photoinactivation. This was confirmed by using a colony-forming assay. The increased phototoxic effect exerted by such a treatment regime could be explained by an enhanced sensitivity of tubulin to light. Another cytosolic constituent, lactate dehydrogenase, was not photoinactivated by TPPS4 and light.

  16. The impact of aerosols on solar ultraviolet radiation and photochemical smog.

    PubMed

    Dickerson, R R; Kondragunta, S; Stenchikov, G; Civerolo, K L; Doddridge, B G; Holben, B N

    1997-10-31

    Photochemical smog, or ground-level ozone, has been the most recalcitrant of air pollution problems, but reductions in emissions of sulfur and hydrocarbons may yield unanticipated benefits in air quality. While sulfate and some organic aerosol particles scatter solar radiation back into space and can cool Earth's surface, they also change the actinic flux of ultraviolet (UV) radiation. Observations and numerical models show that UV-scattering particles in the boundary layer accelerate photochemical reactions and smog production, but UV-absorbing aerosols such as mineral dust and soot inhibit smog production. Results could have major implications for the control of air pollution. PMID:9346474

  17. solar cells

    Microsoft Academic Search

    Ben Minnaert; Marc Burgelman

    Basic solar cell characteristics were examined in an organic bulk heterojunction device. The active layer is a spincoated organic blend of a p- material (MEH-PPV) and an n-material (the fullerene derivative PCBM), sandwiched between a transparent ITO-PEDOT\\/PSS electrode and an Al\\/LiF back-contact. We carried out light and dark I-V and spectral response measurements and measured the transparency of the active

  18. Amorphous silicon solar cells

    Microsoft Academic Search

    K. Takahashi; M. Konagai

    1986-01-01

    The fabrication, performance, and applications of a-Si solar cells are discussed, summarizing the results of recent experimental investigations and trial installations. Topics examined include the fundamental principles and design strategies of solar power installations; the characteristics of monocrystalline-Si solar cells; techniques for reducing the cost of solar cells; independent, linked, and hybrid solar power systems; proposed satellite solar power systems;

  19. Mars atmospheric loss and isotopic fractionation by solar-wind-induced sputtering and photochemical escape

    NASA Technical Reports Server (NTRS)

    Jakosky, B. M.; Pepin, R. O.; Johnson, R. E.; Fox, J. L.

    1993-01-01

    We examine the effects of loss of Mars atmospheric constituents by solar-wind-induced sputtering and by photochemical escape during the last 3.8 b.y. Sputtering is capable of efficiently removing all species from the upper atmosphere including the light noble gases; N is removed by photochemical processes as well. Due to diffusive separation (by mass) above the homopause, removal from the top of the atmosphere will fractionate the isotopes of each species with the lighter mass being preferentially lost. For C and O, this allows us to determine the size of nonatmospheric reservoirs that mix with the atmosphere; these reservoirs can be CO2 adsorbed in the regolith or H2O in the polar ice caps. We have constructed both simple analytical models and time-dependent models of the loss from and supply of volatiles to the Martian atmosphere.

  20. Mars atmosphere loss and isotopic fractionation by solar-wind-induced sputtering and photochemical escape

    NASA Technical Reports Server (NTRS)

    Jakosky, B. M.; Pepin, R. O.; Johnson, R. E.; Fox, J. L.

    1993-01-01

    The effects of loss of Mars atmospheric constituents by solar-wind-induced sputtering and by photochemical escape during the last 3.8 b.y. were examined. Sputtering is capable of efficiently removing all species from the upper atmosphere, including the light noble gases; N also is removed by photochemical processes. Due to the diffusive separation by mass above the homopause, removal from the top of the atmosphere will fractionate the isotopes of each species, with the lighter mass being preferentially lost. For C and O, this allows us to determine the size of nonatmospheric reservoirs that mix with the atmosphere; these reserviors can be accounted for by exchange with CO2 adsorbed in the regolith and with H2O in the polar ice deposits. Both simple analytical models and time-dependent models of the loss of volatiles from and supply to the Martian atmosphere were constructed. Both Ar and Ne require continued replenishment from outgassing over geologic time.

  1. Optimization of a Solar Simulator for Planetary-photochemical Studies

    NASA Astrophysics Data System (ADS)

    Es-sebbar, Et-touhami; Bénilan, Yves; Fray, Nicolas; Cottin, Hervé; Jolly, Antoine; Gazeau, Marie-Claire

    2015-06-01

    Low-temperature microwave-powered plasma based on hydrogen and hydrogen with noble gas mixtures are widely used as a continuous vacuum ultraviolet (VUV) source in laboratory experiments carried out to mimic the photochemistry in astrophysical environments. In this work, we present a study dedicated to optimizing such sources in terms of mono-chromaticity at Ly? (H(Ly?) line at 121.6 nm ? 10.2 eV) and high spectral irradiance. We report the influence on the emission spectrum of a wide range of experimental conditions including gas composition (pure H2, pure He, and H2/He mixture), gas pressure, flow rates, and microwave power. The absolute spectral irradiance delivered by this VUV light source has been measured. With a microwave input power of 100 W, the best conditions for producing a quasi-monochromatic source are a 1% H2/He gas mixture at a total pressure of 5 mbar and a flow rate of 2 sccm. By changing the microwave input power from 30 to 120 W, H(Ly?) increases by more than one order of magnitude. A comparison between the current measurements and the solar VUV spectral irradiance is reported over 115–170 nm.

  2. Array of solar cells

    Microsoft Academic Search

    1981-01-01

    An arrangement or array of solar cells comprises a plurality of cells each having contacting connectors which establish an electrically conducting connection between the individual solar cells. Each solar cell has a connector which projects slightly from the edge thereof and is of a selected profile or shape such that the contacting connectors of adjacent cells may be overlapped and

  3. Solar cell shingle

    Microsoft Academic Search

    A. F. Forestieri; A. F. Ratajczak; L. G. Sidorak

    1977-01-01

    A solar cell shingle was made of an array of solar cells on a lower portion of a substantially rectangular shingle substrate made of fiberglass cloth or the like. The solar cells may be encapsulated in flourinated ethylene propylene or some other weatherproof translucent or transparent encapsulant to form a combined electrical module and a roof shingle. The interconnected solar

  4. Effect of photochemically oxidized carbon nanotubes on the deposition of platinum nanoparticles for fuel cell catalysts

    Microsoft Academic Search

    In Young Jang; Sun Hyung Lee; Ki Chul Park; Winadda Wongwiriyapan; Chan Kim; Katsuya Teshima; Shuji Oishi; Yong Jung Kim; Morinobu Endo

    2009-01-01

    The applicability of photochemically oxidized multi-walled carbon nanotubes (MWCNTs) to support materials for fuel cell catalysts has been examined in comparison with the MWCNTs treated and untreated by nitric acid. The photochemical oxidation of MWCNTs under vacuum ultraviolet (VUV, ?=172nm) irradiation introduces oxygen functional groups onto the surface of the nanotubes with generating new defects on their structure. The VUV-induced

  5. Polymer solar cells

    Microsoft Academic Search

    Gang Li; Rui Zhu; Yang Yang

    2012-01-01

    Recent progress in the development of polymer solar cells has improved power-conversion efficiencies from 3% to almost 9%. Based on semiconducting polymers, these solar cells are fabricated from solution-processing techniques and have unique prospects for achieving low-cost solar energy harvesting, owing to their material and manufacturing advantages. The potential applications of polymer solar cells are broad, ranging from flexible solar

  6. Indium phosphide solar cells

    NASA Technical Reports Server (NTRS)

    Weinberg, Irving

    1991-01-01

    The direction for InP solar cell research; reduction of cell cost; increase of cell efficiency; measurements needed to better understand cell performance; n/p versus p/n; radiation effects; major problems in cell contacting; and whether the present level of InP solar cell research in the USA should be maintained, decreased, or increased were considered.

  7. The use of the solar energy in photochemical and photocatalytic processes

    NASA Astrophysics Data System (ADS)

    Kuburovic, Natasha D.; Valent, Vladimir J.; Todorovic, Marija S.

    2003-06-01

    The increasing use of the Earth's natural resources has generated increasing disposal of waste products and contamination of the environment. Many of these products are organic chemicals. Characteristic examples of waste products in the atmosphere, hydrosphere and soil are insecticides, herbicides and pesticides used to protect crops, accidental leakages and spills, and the continual discharge of waste by products in effluent streams from petrochemical and essential industries. To purify these contaminated atmospheres, hydrosphere and soil a procedure and process has been developing with minimal specific consumption energy from a renewable energy source. This paper will provide a survey and analysis of the parameters, thermal efficiency and conversion energy in the use of solar energy in the photochemical and photocatalytic degradation processes of organic effluents. As a consequence of the use of solar energy in the degradation of these effluents, a conceptual solution of a technical-technological and photocatalytic process is given for effluents which are located in watercourses and soil in Yugoslavia.

  8. Amorphous silicon solar cells

    SciTech Connect

    Takahashi, K.; Konagai, M.

    1986-01-01

    The fabrication, performance, and applications of a-Si solar cells are discussed, summarizing the results of recent experimental investigations and trial installations. Topics examined include the fundamental principles and design strategies of solar power installations; the characteristics of monocrystalline-Si solar cells; techniques for reducing the cost of solar cells; independent, linked, and hybrid solar power systems; proposed satellite solar power systems; and the use of solar cells in consumer appliances. Consideration is given to the history of a-Si, a-Si fabrication techniques, quality criteria for a-Si films, solar cells based on a-Si, and techniques for increasing the efficiency and lowering the cost of a-Si solar cells. Graphs, diagrams, drawings, and black-and-white and color photographs are provided. 136 references.

  9. Amorphous silicon solar cells

    NASA Astrophysics Data System (ADS)

    Takahashi, K.; Konagai, M.

    The fabrication, performance, and applications of a-Si solar cells are discussed, summarizing the results of recent experimental investigations and trial installations. Topics examined include the fundamental principles and design strategies of solar power installations; the characteristics of monocrystalline-Si solar cells; techniques for reducing the cost of solar cells; independent, linked, and hybrid solar power systems; proposed satellite solar power systems; and the use of solar cells in consumer appliances. Consideration is given to the history of a-Si, a-Si fabrication techniques, quality criteria for a-Si films, solar cells based on a-Si, and techniques for increasing the efficiency and lowering the cost of a-Si solar cells. Graphs, diagrams, drawings, and black-and-white and color photographs are provided.

  10. Solar cell shingle

    Microsoft Academic Search

    A. F. Forestieri; A. F. Ratajczak; L. G. Sidorak

    1976-01-01

    A solar cell shingle may be made of an array of solar cells on a lower portion of a substantially rectangular shingle substrate made of fiberglass cloth or the like. The solar cells may be encapsulated in fluorinated ethylene propylene or some other weatherproof translucent or transparent encapsulant to form a combined electrical module and a roof shingle. The interconnected

  11. Solar-cell project

    Microsoft Academic Search

    B. Mortensen; J. Jensen

    1980-01-01

    Commercially available solar cells and battery systems were tested. The details of the experimental solar cell\\/battery array placed on the roof of the Jutland Telephone telestation near Aarhus, Denmark are described. A survey of module calculations and meteorological data in this region is given. The systems tested, their components, solar cell arrays and mechanical and electrical equipment are described and

  12. Solar Photovoltaic Cells.

    ERIC Educational Resources Information Center

    Mickey, Charles D.

    1981-01-01

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

  13. Photochemical deposition of cobalt-based oxygen evolving catalyst on a semiconductor photoanode for solar oxygen production

    Microsoft Academic Search

    Ellen M. P. Steinmiller; Kyoung-Shin Choi

    2009-01-01

    This study describes the photochemical deposition of Co-based oxygenevolutioncatalystsonasemiconductorphotoanodeforuse in solar oxygen evolution. In the photodeposition process, elec- tron-holepairsaregeneratedinasemiconductoruponillumination and the photogenerated holes are used to oxidize Co 2 ions to Co 3 ions, resulting in the precipitation of Co 3 -based catalysts on the semiconductor surface. Both photodeposition of the catalyst and solar O2 evolution are photo-oxidation reactions using

  14. A photometric approach of fluorescent solar concentrators. Role of diffuse reflectors and spectral sensitivity of solar cells

    E-print Network

    Paris-Sud XI, Université de

    plates, and the spectral matching of the radiant flux to the photovoltaic cell sensitivity. Experiments suited to the spectral sensitivity of the cells ; - the photochemical stability of organic fluorophores and spectral sensitivity of solar cells J. Mugnier, Y. Dordet, J. Pouget and B. Valeur Laboratoire de Chimie

  15. Heterojunction solar cell

    DOEpatents

    Olson, Jerry M. (Lakewood, CO)

    1994-01-01

    A high-efficiency single heterojunction solar cell wherein a thin emitter layer (preferably Ga.sub.0.52 In.sub.0.48 P) forms a heterojunction with a GaAs absorber layer. The conversion effiency of the solar cell is at least 25.7%. The solar cell preferably includes a passivating layer between the substrate and the absorber layer. An anti-reflection coating is preferably disposed over the emitter layer.

  16. Solar cell encapsulation

    NASA Technical Reports Server (NTRS)

    Gupta, Amitava (Inventor); Ingham, John D. (Inventor); Yavrouian, Andre H. (Inventor)

    1983-01-01

    A polymer syrup for encapsulating solar cell assemblies. The syrup includes uncrosslinked poly(n-butyl)acrylate dissolved in n-butyl acrylate monomer. Preparation of the poly(n-butyl)acrylate and preparation of the polymer syrup is disclosed. Methods for applying the polymer syrup to solar cell assemblies as an encapsulating pottant are described. Also included is a method for solar cell construction utilizing the polymer syrup as a dual purpose adhesive and encapsulating material.

  17. Solar cell design study

    Microsoft Academic Search

    M. F. Lamorte; J. R. Hauser; M. A. Littlejohn; M. Simons

    1977-01-01

    This report reviews the present state-of-the-art in the technology of selected III-V compounds most applicable to solar cells. Emphasis is placed on those areas of III-V materials technology that can be advanced most effectively in the development of high efficiency solar cells for use in the near-earth space environment. Solar cell configurations evaluated or modeled include homojunctions, heterojunctions, Schottky barriers,

  18. Space solar cell research

    NASA Technical Reports Server (NTRS)

    Flood, Dennis J.

    1989-01-01

    A brief overview is given of the scope of the NASA space solar cell research and development program. Silicon cells, gallium arsenide cells, indium phosphide cells, and superlattice solar cells are addressed, indicating the state of the art of each type in outer space and their advantages and drawbacks for use in outer space. Contrasts between efficiency in space and on earth are pointed out.

  19. Fundamentals of solar cells

    Microsoft Academic Search

    A. L. Farhenbruch; R. H. Bube

    1983-01-01

    This text is addressed to upper level graduate students with background in solid state physics and to scientists and engineers involved in solar cell research. The author aims to present fundamental physical principles rather than the state-of-the-art. Specific devices are used to illustrate basic phenomena and to indicate possibilities for innovative design. Contents, abridged: Solar insolation. The calculation of solar

  20. Lateral superlattice solar cells

    Microsoft Academic Search

    A. Mascarenhas; Yong Zhang; J. Mirecki Millunchick; R. D. Twesten; E. D. Jones

    1997-01-01

    A novel structure which comprises of a lateral superlattice as the active layer of a solar cell is proposed. If the alternating regions A and B of a lateral superlattice ABABAB... are chosen to have a Type-II band offset, it is shown that the performance of the active absorbing region of the solar cell is optimized. In essence, the Type-II

  1. Intermediate band solar cells

    Microsoft Academic Search

    Antonio Marti

    2010-01-01

    Intermediate band (IB)solar cells aim to exploit the energy of below bandgap energy photons in solar cells. They are based in a material that, in addition to the conventional conduction and valence bands, have an electronic band (named intermediate band) located inside the bandgap and separated from the conduction and valence band by a null density of states. The theoretical

  2. Laser-assisted solar cell metallization processing

    NASA Technical Reports Server (NTRS)

    Dutta, S.

    1984-01-01

    Laser-assisted processing techniques utilized to produce the fine line, thin metal grid structures that are required to fabricate high efficiency solar cells are examined. Two basic techniques for metal deposition are investigated; (1) photochemical decomposition of liquid or gas phase organometallic compounds utilizing either a focused, CW ultraviolet laser (System 1) or a mask and ultraviolet flood illumination, such as that provided by a repetitively pulsed, defocused excimer laser (System 2), for pattern definition, and (2) thermal deposition of metals from organometallic solutions or vapors utilizing a focused, CW laser beam as a local heat source to draw the metallization pattern.

  3. Hydrogen as the solar energy translator. [in photochemical and photovoltaic processes

    NASA Technical Reports Server (NTRS)

    Kelley, J. H.

    1979-01-01

    Many concepts are being investigated to convert sunlight to workable energy forms with emphasis on electricity and thermal energy. The electrical alternatives include direct conversion of photons to electricity via photovoltaic solar cells and solar/thermal production of electricity via heat-energy cycles. Solar cells, when commercialized, are expected to have efficiencies of about 12 to 14 percent. The cells would be active about eight hours per day. However, solar-operated water-splitting process research, initiated through JPL, shows promise for direct production of hydrogen from sunlight with efficiencies of up to 35 to 40 percent. The hydrogen, a valuable commodity in itself, can also serve as a storable energy form, easily and efficiently converted to electricity by fuel cells and other advanced-technology devices on a 24-hour basis or on demand with an overall efficiency of 25 to 30 percent. Thus, hydrogen serves as the fundamental translator of energy from its solar form to electrical form more effectively, and possibly more efficiently, than direct conversion. Hydrogen also can produce other chemical energy forms using solar energy.

  4. Solar cell radiation handbook

    NASA Technical Reports Server (NTRS)

    Tada, H. Y.; Carter, J. R., Jr.

    1977-01-01

    Solar cell theory cells are manufactured, and how they are modeled mathematically is reviewed. The interaction of energetic charged particle radiation with solar cells is discussed in detail 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. Finally, an extensive body of data detailing the degradation of solar cell electrical parameters as a function of 1 MeV electron fluence is presented.

  5. Dye Sensitized Solar Cells

    PubMed Central

    Wei, Di

    2010-01-01

    Dye sensitized solar cell (DSSC) is the only solar cell that can offer both the flexibility and transparency. Its efficiency is comparable to amorphous silicon solar cells but with a much lower cost. This review not only covers the fundamentals of DSSC but also the related cutting-edge research and its development for industrial applications. Most recent research topics on DSSC, for example, applications of nanostructured TiO2, ZnO electrodes, ionic liquid electrolytes, carbon nanotubes, graphene and solid state DSSC have all been included and discussed. PMID:20480003

  6. Lateral superlattice solar cells

    SciTech Connect

    Mascarenhas, A.; Zhang, Y. [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States); Millunchick, J.M.; Twesten, R.D.; Jones, E.D. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

    1997-04-01

    A novel structure which comprises of a lateral superlattice as the active layer of a solar cell is proposed. If the alternating regions A and B of a lateral superlattice ABABAB{hor_ellipsis} are chosen to have a Type-II band offset, it is shown that the performance of the active absorbing region of the solar cell is optimized. In essence, the Type-II lateral superlattice region can satisfy the material requirements for an ideal solar cells active absorbing region, i.e. simultaneously having a very high transition probability for photogeneration and a very long minority carrier recombination lifetime. {copyright} {ital 1997 American Institute of Physics.}

  7. Lateral superlattice solar cells

    SciTech Connect

    Mascarenhas, A.; Zhang, Y. [National Renewable Energy Lab., Golden, CO (United States); Millunchick, J.M.; Twesten, R.D.; Jones, E.D. [Sandia National Labs., Albuquerque, NM (United States)

    1997-10-01

    A novel structure which comprises of a lateral superlattice as the active layer of a solar cell is proposed. If the alternating regions A and B of a lateral superlattice ABABAB... are chosen to have a Type-II band offset, it is shown that the performance of the active absorbing region of the solar cell is optimized. In essence, the Type-II lateral superlattice region can satisfy the material requirements for an ideal solar cells active absorbing region, i.e. simultaneously having a very high transition probability for photogeneration and a very long minority carrier recombination lifetime.

  8. Quantum dot solar cells

    Microsoft Academic Search

    A. J Nozik

    2002-01-01

    Quantum dot (QD) solar cells have the potential to increase the maximum attainable thermodynamic conversion efficiency of solar photon conversion up to about 66% by utilizing hot photogenerated carriers to produce higher photovoltages or higher photocurrents. The former effect is based on miniband transport and collection of hot carriers in QD array photoelectrodes before they relax to the band edges

  9. Nanocrystal Solar Cells

    SciTech Connect

    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.

  10. Photovoltaic solar cell

    DOEpatents

    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.

  11. Photovoltaic solar cell

    DOEpatents

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

    2014-05-20

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

  12. Solar cell array interconnects

    DOEpatents

    Carey, Paul G. (Mountain View, CA); Thompson, Jesse B. (Brentwood, CA); Colella, Nicolas J. (Livermore, CA); Williams, Kenneth A. (Livermore, CA)

    1995-01-01

    Electrical interconnects for solar cells or other electronic components using a silver-silicone paste or a lead-tin (Pb-Sn) no-clean fluxless solder cream, whereby the high breakage of thin (<6 mil thick) solar cells using conventional solder interconnect is eliminated. The interconnects of this invention employs copper strips which are secured to the solar cells by a silver-silicone conductive paste which can be used at room temperature, or by a Pb-Sn solder cream which eliminates undesired residue on the active surfaces of the solar cells. Electrical testing using the interconnects of this invention has shown that no degradation of the interconnects developed under high current testing, while providing a very low contact resistance value.

  13. Screening of solar cells

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

    Because solar cells in a production batch are not identical, screening is performed to obtain similar cells for aggregation into arrays. A common technique for screening is based on a single operating point of the I-V characteristic of the cell, usually the maximum power point. As a result, inferior cell matching may occur at the actual operating points. Screening solar cells based on the entire I-V characteristic will inherently result in more similar cells in the array. An array consisting of more similar cells is likely to have better overall characteristics and more predictable performance. Solar cell screening methods and cell ranking are discussed. The concept of a mean cell is defined as a cell 'best' representing all the cells in the production batch. The screening and ranking of all cells are performed with respect to the mean cell. The comparative results of different screening methods are illustrated on a batch of 50 silicon cells of the Space Station Freedom.

  14. Lateral superlattice solar cells

    Microsoft Academic Search

    A. Mascarenhas; Yong Zhang; J. Mirecki Millunchick; R. D. Twesten; E. D. Jones

    1997-01-01

    A novel structure which comprises of a lateral superlattice as the active layer of a solar cell is proposed. If the alternating regions A and B of a lateral superlattice ABABAB&ellip; are chosen to have a Type-II band offset, it is shown that the performance of the active absorbing region of the solar cell is optimized. In essence, the Type-II

  15. Thin silicon solar cells

    SciTech Connect

    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.

  16. Effects of 1,3-Butadiene, Isoprene, and Their Photochemical Degradation Products on Human Lung Cells

    PubMed Central

    Doyle, Melanie; Sexton, Kenneth G.; Jeffries, Harvey; Bridge, Kevin; Jaspers, Ilona

    2004-01-01

    Because of potential exposure both in the workplace and from ambient air, the known carcinogen 1,3-butadiene (BD) is considered a priority hazardous air pollutant. BD and its 2-methyl analog, isoprene (ISO), are chemically similar but have very different toxicities, with ISO showing no significant carcinogenesis. Once released into the atmosphere, reactions with species induced by sunlight and nitrogen oxides convert BD and ISO into several photochemical reaction products. In this study, we determined the relative toxicity and inflammatory gene expression induced by exposure of A549 cells to BD, ISO, and their photochemical degradation products in the presence of nitric oxide. Gas chromatography and mass spectrometry analyses indicate the initial and major photochemical products produced during these experiments for BD are acrolein, acetaldehyde, and formaldehyde, and products for ISO are methacrolein, methyl vinyl ketone, and formaldehyde; both formed < 200 ppb of ozone. After exposure the cells were examined for cytotoxicity and interleukin-8 (IL-8) gene expression, as a marker for inflammation. These results indicate that although BD and ISO alone caused similar cytotoxicity and IL-8 responses compared with the air control, their photochemical products significantly enhanced cytotoxicity and IL-8 gene expression. This suggests that once ISO and BD are released into the environment, reactions occurring in the atmosphere transform these hydrocarbons into products that induce potentially greater adverse health effects than the emitted hydrocarbons by themselves. In addition, the data suggest that based on the carbon concentration or per carbon basis, biogenic ISO transforms into products with proinflammatory potential similar to that of BD products. PMID:15531432

  17. EE580 Solar Cells Todd J. Kaiser

    E-print Network

    Kaiser, Todd J.

    7/21/2010 1 EE580 ­ Solar Cells Todd J. Kaiser · Lecture 06 · Solar Cell Materials & Structures 1Montana State University: Solar Cells Lecture 6: Solar Cells Solar Cell Technologies · A) Crystalline Silicon · B) Thin Film · C) Group III-IV Cells 2Montana State University: Solar Cells Lecture 6: Solar

  18. Parameterization of solar cells

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

    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.

  19. Transparent solar cell module

    NASA Technical Reports Server (NTRS)

    Antonides, G. J.; Dillard, P. A.; Fritz, W. M.; Lott, D. P.

    1979-01-01

    Modified solar cell module uses high transmission glass and adhesives, and heat dissipation to boost power per unit area by 25% (9.84% efficiency based on cell area at 60 C and 100 mW/sq cm flux). Design is suited for automatic production and is potentially more cost effective.

  20. Primary targets in photochemical inactivation of cells in culture

    Microsoft Academic Search

    Kristian Berg; Stuart G. Jones; Kristian Prydz; Johan Moan

    1995-01-01

    The mechanisms of photoinactivation of NHIK 3025 cells in culture sensitized by tetrasulfonated phenylporphines (TPPS4) are described). Ultracentrifugation studies on postnuclear supernatants indicated that the intracellular distribution of TPPS4 resembles that of (beta) -N-acetyl-D-glucosaminidase ((beta) -AGA), a lysosomal marker enzyme, and that the cytosolic content of TPPS4 is below the detection limit of the ultracentrifugation method. Upon light exposure more

  1. Solar cell radiation damage

    Microsoft Academic Search

    R. L. Crabb

    1994-01-01

    During the past 34 years, silicon or gallium arsenide solar cells have remained the main power source for nearly all spacecraft; power output levels having risen from a few milliwatts (Vanguard 1, 1958) to many kilowatts in the 1970s and 1980s (Skylab, 21 kW; MIR, 10 kW; Hubble Space Telescope, 5 kW). The steady technological progress made in improving solar

  2. Fourth International Conference on Photochemical Conversion and Storage of Solar Energy

    NASA Astrophysics Data System (ADS)

    1982-12-01

    s of 123 papers under the following topics are presented: conversion of sunlight into electrical power and photoassisted electrolysis at semiconductor electrodes; photosensitized reactions on surfaces; the role of porphyrins and chlorophylls in artificial photosynthesis; oxidation reduction photochemistry in homogeneous solutions; photoelectron transfer in organized assemblies; photogalvanic cells and effects; elementary processes in catalytic reactions at the interrace between colloidal microelectrodes and solutions; and luminescent solar collectors and concentrators. Author and subject indexes are included.

  3. Flexible dye solar cells

    Microsoft Academic Search

    Nathalie Rossier-Iten; Toby B. Meyer; Jessica Krueger; Michael Graetzel

    2004-01-01

    Strategies towards flexible solid state solar cells based on nanocrystalline titanium oxide and organic hole conductor were investigated. For the flexible cell geometry a metal foil was used as substrate and a semi-transparent gold layer as counter electrode which allows light transmission (back illumination). The device performance of solid state cells based on SnO2:F coated glass on the one hand

  4. Amorphous silicon solar cells

    Microsoft Academic Search

    D. E. Carlson; R. S. Crandall; J. Dresner; D. Goldstein; J. J. Hanak; A. R. Moore; R. E. Schade; D. L. Staebler; H. A. Weakliem; R. Williams

    1981-01-01

    The photoconductive response of Schottky-barrier and p-i-n solar cell structures was analyzed. It shows that the photoconductivity determines the fill factor, rather than the dark current, as in crystalline silicon cells. An analysis of the I-V curves of p-i-n cells shows that the electron and hole drift lengths are comparable. High conductivity p and n type films (sigma = 1-10

  5. Amorphous silicon solar cells

    Microsoft Academic Search

    W. Juergens; W. Kruehler; M. Moeller; H. Pfleiderer; R. Plaettner; B. Rauscher; W. Stetter

    1983-01-01

    A technique for manufacturing amorphous silicon solar cells is described. Hydrogenated amorphous silicon (a-Si:H) with excellent photoconductivity (ratio of photo and dark conductivity = 10,000 for 0,25 mW\\/sqcm light intensity) photoluminescence, and low density of states was manufactured. Doping behavior in a-Si:H-films and dependence of geometrical cell structure on electrical properties were investigated. A-Si:H-Schottky barrier cells with Pt, Pd, Au

  6. Silicon for solar cells

    NASA Astrophysics Data System (ADS)

    Ciszek, T. F.

    1984-04-01

    An introduction to silicon solar cell technology and photovoltaic device operation is presented. The conventional semiconductor industry techniques for extraction of Si from quartz, purification of silanes, chemical vapor deposition of polycrystalline silicon rods, melt growth of silicon crystals, and fabrication of silicon polished wafers are reviewed. The specific requirements of silicon for solar cells, particularly impurity effects are discussed. Nineteen different crystal growth methods of silicon for solar cells are reviewed (both ingots and sheets). Sheet growth methods are categorized by solid/liquid interface meniscus geometry and degree of shaper/melt interaction. Crystal growth rates and surface area generation rates are analyzed for sheet growth configurations as well as combined ingot growth and wafering approaches. Several methods show promise of achieving high throughput rates. Some of the characteristics of silicon which have led to its role as both a near term and long range premier photovoltaic material are summarized.

  7. Design, characterization and fabrication of silicon solar cells for ?50% efficient 6-junction tandem solar cells

    Microsoft Academic Search

    Ngwe Soe Zin; Andrew Blakers; Evan Franklin; Vernie Everett

    2008-01-01

    A major objective for photovoltaic conversion is to develop high efficiency solar cells. Many approaches are under investigation - Multiple Junction Solar Cell, Multiple Spectrum Solar Cell, Multiple Absorption Path Solar Cell, Multiple Energy Solar Cell, and Multiple Temperature Solar Cells [1]. The Multiple Junction Solar Cell approach based on a six-junction tandem solar cell has been adopted to achieve

  8. Monolithic tandem solar cell

    DOEpatents

    Wanlass, Mark W. (Golden, CO)

    1991-01-01

    A single-crystal, monolithic, tandem, photovoltaic solar cell is described which includes (a) an InP substrate having upper and lower surfaces, (b) a first photoactive subcell on the upper surface of the InP substrate, and (c) a second photoactive subcell on the first subcell. The first photoactive subcell is GaInAsP of defined composition. The second subcell is InP. The two subcells are lattice matched. The solar cell can be provided as a two-terminal device or a three-terminal device.

  9. Solar cell radiation handbook

    NASA Technical Reports Server (NTRS)

    Carter, J. R., Jr.; Tada, H. Y.

    1973-01-01

    A method is presented for predicting the degradation of a solar array in a space radiation environment. Solar cell technology which emphasizes the cell parameters that degrade in a radiation environment, is discussed along with the experimental techniques used in the evaluation of radiation effects. Other topics discussed include: theoretical aspects of radiation damage, methods for developing relative damage coefficients, nature of the space radiation environment, method of calculating equivalent fluence from electron and proton energy spectrums and relative damage coefficients, and comparison of flight data with estimated degradation.

  10. EE580 Solar Cells Todd J. Kaiser

    E-print Network

    Kaiser, Todd J.

    7/21/2010 1 EE580 ­ Solar Cells Todd J. Kaiser · Lecture 08 · Solar Cell Characterization 1Montana State University: Solar Cells Lecture 8: Characterization Solar Cell Operation n Emitter p Base Rear completing the circuit 2Montana State University: Solar Cells Lecture 8: Characterization Solar Cell

  11. Artificial photochemical nitrogen cycle to produce nitrogen and hydrogen from ammonia by platinized TiO2 and its application to a photofuel cell.

    PubMed

    Kaneko, M; Gokan, N; Katakura, N; Takei, Y; Hoshino, M

    2005-03-28

    Photochemical artificial nitrogen cycle was reported to produce dinitrogen and dihydrogen by photodecomposing ammonia with platinized TiO2, and its application to a photofuel cell with a nanoporous TiO2 film electrode, a new concept of a fuel cell to photochemically produce electricity and H2 from ammonia, was proposed. PMID:15770281

  12. Nanostructured SIS solar cells

    NASA Astrophysics Data System (ADS)

    Fuechsel, K.; Schulz, U.; Kaiser, N.; Käsebier, T.; Kley, E.-B.; Tünnermann, A.

    2010-05-01

    Due to their electrical conductivity and transparency in the visible spectral range, transparent conductive oxides (TCOs) are suitable as transparent front electrodes for multiple cell concepts. One promising device is a semiconductor-insulator-semiconductor (SIS) solar cell, in which the TCO induces the pn juntion and acts as a transparent electrode at the same time. Due to its work function, the thin TCO layer leads to the inversion of the subsurface region. The high refractive index of transparent conductive oxides enables antireflection coating in a limited spectral range. One approach to achieve broadband antireflection properties with effective light coupling into the absorber is a nanostructured silicon interface. For large area modifications of silicon, the inductive coupled plasma (ICP) etching technology is a possible technique. The combination of the nanostructured surface and the SIS system leads to a novel solar cell concept with promising properties and a simple production process. In our study, we used pulsed dc magnetron sputtering for the deposition of thin ITO films on p-doped unstructured and ICP-structured silicon substrates. Optical and structural properties have been analyzed. Furthermore, the solar cell performance of the first devices under AM1.5G illumination will be shown and discussed.

  13. Very high efficiency solar cells

    NASA Astrophysics Data System (ADS)

    Barnett, Allen; Kirkpatrick, Douglas; Honsberg, Christiana

    2006-08-01

    The Defense Advanced Research Projects Agency has initiated the Very High Efficiency Solar Cell (VHESC) program to address the critical need of the soldier for power in the field. Very High Efficiency Solar Cells for portable applications that operate at greater than 55 percent efficiency in the laboratory and 50 percent in production are being developed. We are integrating the optical design with the solar cell design, and have entered previously unoccupied design space that leads to a new architecture paradigm. An integrated team effort is now underway that requires us to invent, develop and transfer to production these new solar cells. Our approach is driven by proven quantitative models for the solar cell design, the optical design and the integration of these designs. We start with a very high performance crystalline silicon solar cell platform. Examples will be presented. Initial solar cell device results are shown for devices fabricated in geometries designed for this VHESC Program.

  14. Solar PV- How A Solar Cell Works

    NSDL National Science Digital Library

    Levander, Alejandro

    The Advanced Technology Environmental and Energy Center (ATEEC) provides this document which will help instructors or anyone who would like to understand the basics of solar power and solar cells. Users must download this resource for viewing, which requires a free log-in. There is no cost to download the item.

  15. Quantum Dot Solar Cells

    NASA Technical Reports Server (NTRS)

    Raffaelle, Ryne P.; Castro, Stephanie L.; Hepp, Aloysius; Bailey, Sheila G.

    2002-01-01

    We have been investigating the synthesis of quantum dots of CdSe, CuInS2, and CuInSe2 for use in an intermediate bandgap solar cell. We have prepared a variety of quantum dots using the typical organometallic synthesis routes pioneered by Bawendi, et. al., in the early 1990's. However, unlike previous work in this area we have also utilized single-source precursor molecules in the synthesis process. We will present XRD, TEM, SEM and EDS characterization of our initial attempts at fabricating these quantum dots. Investigation of the size distributions of these nanoparticles via laser light scattering and scanning electron microscopy will be presented. Theoretical estimates on appropriate quantum dot composition, size, and inter-dot spacing along with potential scenarios for solar cell fabrication will be discussed.

  16. Solar-Cell String Conveyor

    NASA Technical Reports Server (NTRS)

    Frasch, W.; Ciavola, S.

    1982-01-01

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

  17. Compound polycrystalline solar cells

    Microsoft Academic Search

    Robert W. Birkmire

    2001-01-01

    A historical perspective on the development of polycrystalline thin-film solar cells based on CdTe and CuInSe2 is presented, and recent progress of these thin-film technologies is discussed. Impressive improvements in the efficiency of laboratory scale devices has not been easy to translate to the manufacturing environment, principally due to our lack of understanding of the basic science and engineering of

  18. Nanocrystalline electrochemical solar cells

    SciTech Connect

    McEvoy, A.J.; Graetzel, M. [Ecole Polytechnique Federale, Lausanne (Switzerland). Inst. de Chimie-Physique; Wittkopf, H.; Jestel, D.; Benemann, J. [Flachglas AG, Gelsenkirchen (Germany)

    1994-12-31

    Standard solar cells exploit the physics of semiconductors in which the energy of absorbed photons excites charge-carrier pairs which are subsequently separated by the influence of a solid state junction to provide a photovoltage. In the nanocrystalline electrochemical cell, the optical absorber is a dye monolayer which after photo-excitation injects electrons into a semiconductor substrate, with charge neutrality being restored by a chemical redox reaction. The circuit is completed through an electrolyte and a metallic counterlectrode. Present performance, industrial engagement in research and development and commercial prospects are presented.

  19. Solar cells - A technology assessment

    Microsoft Academic Search

    J. R. Bolton

    1983-01-01

    A qualitative assessment is made of the state-of-the-art in solar cell development and materials, together with projections of areas of future progress. The benefits and deficiencies of solar cells are surveyed, including the passive, low maintenance qualities of solar cell panels, the necessity of having a back-up system at night, and the low power conversion efficiencies available from current cells,

  20. Photochemical internalization of bleomycin and temozolomide - in vitro studies on the glioma cell line F98.

    PubMed

    Gederaas, Odrun A; Hauge, Anette; Ellingsen, Pål G; Berg, Kristian; Altin, Dag; Bardal, Tora; Høgset, Anders; Lindgren, Mikael

    2015-07-01

    Here we evaluate the photosensitizer meso-tetraphenyl chlorin disulphonate (TPCS2a) in survival studies of rat glioma cancer cells in combination with the novel photochemical internalization (PCI) technique. The tested anticancer drugs were bleomycin (BLM) and temozolomide (TMZ). Glioma cells were incubated with TPCS2a (0.2 ?g ml(-1), 18 h, 37 °C) before BLM or TMZ stimulation (4 h) prior to red light illumination (652 nm, 50 mW cm(-2)). The cell survival after BLM (0.5 ?m)-PCI (40 s light) quantified using the MTT assay was reduced to about 25% after 24 h relative to controls, and to 31% after TMZ-PCI. The supplementing quantification by clonogenic assays, using BLM (0.1 ?m), indicated a long-term cytotoxic effect: the surviving fraction of clonogenic cells was reduced to 5% after light exposure (80 s) with PCI, compared to 70% in the case of PDT. In parallel, structural and morphological changes within the cells upon light treatment were examined using fluorescence microscopy techniques. The present study demonstrates that PCI of BLM is an effective method for killing F98 glioma cells, but smaller effects were observed using TMZ following the "light after" strategy. The results are the basis for further in vivo studies on our rat glioma cancer model using PDT and PCI. PMID:26088711

  1. Solar cell module lamination process

    DOEpatents

    Carey, Paul G. (Mountain View, CA); Thompson, Jesse B. (Brentwood, CA); Aceves, Randy C. (Tracy, CA)

    2002-01-01

    A solar cell module lamination process using fluoropolymers to provide protection from adverse environmental conditions and thus enable more extended use of solar cells, particularly in space applications. A laminate of fluoropolymer material provides a hermetically sealed solar cell module structure that is flexible and very durable. The laminate is virtually chemically inert, highly transmissive in the visible spectrum, dimensionally stable at temperatures up to about 200.degree. C. highly abrasion resistant, and exhibits very little ultra-violet degradation.

  2. Monolithic tandem solar cell

    DOEpatents

    Wanlass, Mark W. (Golden, CO)

    1994-01-01

    A single-crystal, monolithic, tandem, photovoltaic solar cell is described which includes (a) an InP substrate having upper and lower surfaces, (b) a first photoactive subcell on the upper surface of the InP substrate, (c) a second photoactive subcell on the first subcell; and (d) an optically transparent prismatic cover layer over the second subcell. The first photoactive subcell is GaInAsP of defined composition. The second subcell is InP. The two subcells are lattice matched.

  3. Radiative cooling for solar cells

    NASA Astrophysics Data System (ADS)

    Zhu, Linxiao; Raman, Aaswath; Wang, Ken X.; Anoma, Marc A.; Fan, Shanhui

    2015-03-01

    Standard solar cells heat up under sunlight, and the resulting increased temperature of the solar cell has adverse consequences on both its efficiency and its reliability. We introduce a general approach to radiatively lower the operating temperature of a solar cell through sky access, while maintaining its sunlight absorption. We present first an ideal scheme for the radiative cooling of solar cells. For an example case of a bare crystalline silicon solar cell, we show that the ideal scheme can passively lower the operating temperature by 18.3 K. We then show a microphotonic design based on realistic material properties, that approaches the performance of the ideal scheme. We also show that the radiative cooling effect is substantial, even in the presence of significant non-radiative heat change, and parasitic solar absorption in the cooling layer, provided that we design the cooling layer to be sufficiently thin.

  4. Solar Panel of Photovoltaic Cells

    USGS Multimedia Gallery

    Solar panels or arrays of photovoltaic cells convert renewable solar radiation into electricity by a clean and environmentally sound means. Collected solar energy can either be used instantly or stored in batteries for later use. These systems can be used as a component of a larger photovoltaic syst...

  5. High intensity solar cells

    SciTech Connect

    Schwartz, R.J.; Gray, J.L.; Lundstrom, M.S.

    1986-01-01

    Two computer codes, SCAP1D and SCAP2D, are being used to analyze silicon concentrator solar cells. The models used in these codes are constantly being evaluated for accuracy and are updated as necessary. For example, the effects of carrier-carrier scattering on mobility have been included and documented in this report. In addition, modifications to SCAP2D have been made to allow the modeling of minority carrier reflecting contacts. A semianalytical model was developed and used to estimate the theoretical limit of efficiency of silicon concentrator cells. It is predicted that efficiencies near 30% may be possible at high concentration. Reprints of published papers are included in the appendices.

  6. Thin film solar cell workshop

    NASA Technical Reports Server (NTRS)

    Armstrong, Joe; Jeffrey, Frank

    1993-01-01

    A summation of responses to questions posed to the thin-film solar cell workshop and the ensuing discussion is provided. Participants in the workshop included photovoltaic manufacturers (both thin film and crystalline), cell performance investigators, and consumers.

  7. Commercialization of Novel Organic Solar Cells

    E-print Network

    Kassegne, Samuel Kinde

    Commercialization of Novel Organic Solar Cells Master of Engineering Final Report Shanel C. Miller................................................................................................................... 12 2.1 How do Solar Cells Work?.................................................................................................. 12 2.2 Types of Solar Cells that Exist Today

  8. The challenges of organic polymer solar cells

    E-print Network

    Saif Addin, Burhan K. (Burhan Khalid)

    2011-01-01

    The technical and commercial prospects of polymer solar cells were evaluated. Polymer solar cells are an attractive approach to fabricate and deploy roll-to-roll processed solar cells that are reasonably efficient (total ...

  9. Thermomechanical stressing of solar cells

    Microsoft Academic Search

    Marek Novotný; L. Jakubka; P. Cejtchaml; I. Szendiuch

    2006-01-01

    This paper describes recent developments made to the finite element modeling of solar cells, extending its capability to handle viscoplastic behavior. It also presents the validation of this approach and results obtained for an interconnection of solar cells. Lifetime predictions are made using the creep strain energy based models of Darveaux. This study discusses the analysis methodologies as implemented in

  10. An Introduction to Solar Cells

    ERIC Educational Resources Information Center

    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…

  11. Thin monocrystalline silicon solar cells

    SciTech Connect

    Muenzer, K.A.; Holdermann, K.T.; Schlosser, R.E.; Sterk, S.

    1999-10-01

    One of the most effective approaches for a cost reduction of crystalline silicon solar cells is the better utilization of the crystals by cutting thinner wafers. However, such thin silicon wafer must have sufficient mechanical strength to maintain a high mechanical yield in cell and module manufacturing. The electrical performance of thin cells drops strongly with decreasing cell thickness if solar cell manufacturing technologies without a backside passivation of a back-surface-field (BSF) are applied. However, with the application of a BSF, stable efficiencies of over 17%, even with decreasing cell thickness, have been reached. Thin solar cells show lower photodegradation, as is normally observed for Cz-silicon cells with today's standard thickness (about 300 {micro}m) because of a higher ratio of the diffusion length compared to the cell thickness. Cells of about 100--150 {micro}m thickness fabricated with the production Cz-silicon show almost no photodegradation. Furthermore, thin boron BSF cells have a pronounced efficiency response under backside illumination. The backside efficiency increases with decreasing cell thickness and reaches 60% of the frontside cell efficiency for 150 {micro}m solar cells and also for solar modules assembled of 36 cells of a thickness of 150 {mu}m. Assuming, for example, a rearside illumination of 150 W/m{sub 2}, this results in an increased module power output of about 10% relatively.

  12. GaAs Solar Cell Radiation Handbook

    NASA Technical Reports Server (NTRS)

    Anspaugh, B. E.

    1996-01-01

    History of GaAs solar cell development is provided. Photovoltaic equations are described along with instrumentation techniques for measuring solar cells. Radiation effects in solar cells, electrical performance, and spacecraft flight data for solar cells are discussed. The space radiation environment and solar array degradation calculations are addressed.

  13. An improved solar cell circuit model for organic solar cells

    Microsoft Academic Search

    B. Mazhari

    2006-01-01

    The validity of conventional circuit model for interpreting results obtained using organic solar cells is examined. It is shown that the central assumption in the model that photo-generated current remains constant from short-circuit to open-circuit condition may not hold for organic cells. An improved model based on the photovoltaic response of organic solar cells is proposed and a method of

  14. Isomerization and Aggregation of the Solar Cell Dye D149

    PubMed Central

    2012-01-01

    D149, a metal-free indoline dye, is one of the most promising sensitizers for dye-sensitized solar cells (DSSCs) and has shown very high solar energy conversion efficiencies of 9%. Effective electron injection from the excited state is a prerequisite for high efficiencies and is lowered by competing deactivation pathways. Previous investigations have shown surprisingly short-lived excited states for this dye, with maximum lifetime components of 100–720 ps in different solvents and less than 120 ps for surface-adsorbed D149. Using steady-state and time-resolved fluorescence, we have investigated the photochemical properties of D149 in nonpolar and polar solvents, polymer matrices, and adsorbed on ZrO2, partially including a coadsorbent. In solution, excitation to the S2 state yields a product that is identified as a photoisomer. The reaction is reversible, and the involved double-bond is identified by NMR spectroscopy. Our results further show that lifetimes of 100–330 ps in the solvents used are increased to more than 2 ns for D149 in polymer matrices and on ZrO2. This is in part attributed to blocked internal motion due to steric constraint. Conversely, concentration-dependent aggregation leads to a dramatic reduction in lifetimes that can affect solar cell performance. Our results explain the unexpectedly short lifetimes observed previously. We also show that photochemical properties such as lifetimes determined in solution are different from the ones determined on semiconductor surfaces used in solar cells. The obtained mechanistic understanding should help develop design strategies for further improvement of solar cell dyes. PMID:23378868

  15. Back wall solar cell

    NASA Technical Reports Server (NTRS)

    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.

  16. Germanium Nanocrystal Solar Cells

    NASA Astrophysics Data System (ADS)

    Holman, Zachary Charles

    Greenhouse gas concentrations in the atmosphere are approaching historically unprecedented levels from burning fossil fuels to meet the ever-increasing world energy demand. A rapid transition to clean energy sources is necessary to avoid the potentially catastrophic consequences of global warming. The sun provides more than enough energy to power the world, and solar cells that convert sunlight to electricity are commercially available. However, the high cost and low efficiency of current solar cells prevent their widespread implementation, and grid parity is not anticipated to be reached for at least 15 years without breakthrough technologies. Semiconductor nanocrystals (NCs) show promise for cheap multi-junction photovoltaic devices. To compete with photovoltaic materials that are currently commercially available, NCs need to be inexpensively cast into dense thin films with bulk-like electrical mobilities and absorption spectra that can be tuned by altering the NC size. The Group II-VI and IV-VI NC communities have had some success in achieving this goal by drying and then chemically treating colloidal particles, but the more abundant and less toxic Group IV NCs have proven more challenging. This thesis reports thin films of plasma-synthesized Ge NCs deposited using three different techniques, and preliminary solar cells based on these films. Germanium tetrachloride is dissociated in the presence of hydrogen in a nonthermal plasma to nucleate Ge NCs. Transmission electron microscopy and X-ray diffraction indicate that the particles are nearly monodisperse (standard deviations of 10-15% the mean particle diameter) and the mean diameter can be tuned from 4-15 nm by changing the residence time of the Ge NCs in the plasma. In the first deposition scheme, a Ge NC colloid is formed by reacting nanocrystalline powder with 1-dodecene and dispersing the functionalized NCs in a solvent. Films are then formed on substrates by drop-casting the colloid and allowing it to dry. As-deposited films are electrically insulating due to the long hydrocarbon molecules separating neighboring particles; however, mass spectrometry shows that annealing treatments successfully decompose these molecules. After annealing at 250 °C, Ge NC films exhibit conductivities as large as 10-6 S/cm. In the second film deposition scheme, a Ge NC colloid is formed by dispersing Ge NCs in select solvents without further surface modification. While these "bare" NCs quickly agglomerate and flocculate in nearly all non-polar solvents, they remain stable in benzonitrile and 1,2-dichlorobenzene, among others. Thin-film field-effect transistors have been fabricated by spinning Ge NC colloids onto substrates and the films have been subjected to various annealing procedures. The devices show n-type, p -type, or ambipolar behavior depending on the annealing conditions, with Ge NC films annealed at 300°C exhibiting electron saturation mobilities greater than 10-2 cm2/Vs and on-to-off ratios of 104. The final film deposition scheme involves the impaction of Ge NCs onto substrates downstream of the synthesis plasma via acceleration of the NCs through an orifice. This technique produces highly uniform films with densities greater than 50% of the density of bulk Ge. By varying the size of the Ge NCs, we have measured films with band gaps ranging from the bulk value of 0.7 eV to over 1.1 eV for films of 4 nm Ge NCs. Having deposited dense thin films with tunable band gaps and respectable mobilities, we have begun fabricating bilayer solar cells consisting of heterojunctions between Ge NC films and P3HT, Si NCs, or Si wafers. Preliminary devices exhibit opencircuit voltages and short-circuit currents as large as 0.3 V and 4 mA/cm 2, respectively.

  17. Bulb mounting of solar cell

    SciTech Connect

    Thompson, M.E.

    1983-04-05

    An energy converting assembly is provided for parasiting of light from a fluorescent light bulb utilizing a solar cell. The solar cell is mounted on a base member elongated in the dimension of elongation of the fluorescent bulb, and electrical interconnections to the cell are provided. A flexible sheet of opaque material having a flat white interior reflective surface surrounds the fluorescent bulb and reflects light emitted from the bulb back toward the bulb and the solar cell. The reflective sheet is tightly held in contact with the bottom of the bulb by adhesive, a tie strap, an external clip, or the like.

  18. Photochemical internalisation of chemotherapy potentiates killing of multidrug-resistant breast and bladder cancer cells.

    PubMed

    Adigbli, D K; Wilson, D G G; Farooqui, N; Sousi, E; Risley, P; Taylor, I; Macrobert, A J; Loizidou, M

    2007-08-20

    Multidrug resistance (MDR) is the major confounding factor in adjuvant solid tumour chemotherapy. Increasing intracellular amounts of chemotherapeutics to circumvent MDR may be achieved by a novel delivery method, photochemical internalisation (PCI). PCI consists of the co-administration of drug and photosensitiser; upon light activation the latter induces intracellular release of organelle-bound drug. We investigated whether co-administration of hypericin (photosensitiser) with mitoxantrone (MTZ, chemotherapeutic) plus illumination potentiates cytotoxicity in MDR cancer cells. We mapped the extent of intracellular co-localisation of drug/photosensitiser. We determined whether PCI altered drug-excreting efflux pump P-glycoprotein (Pgp) expression or function in MDR cells. Bladder and breast cancer cells and their Pgp-overexpressing MDR subclones (MGHU1, MGHU1/R, MCF-7, MCF-7/R) were given hypericin/MTZ combinations, with/without blue-light illumination. Pilot experiments determined appropriate sublethal doses for each. Viability was determined by the 3-[4,5-dimethylthiazolyl]-2,5-diphenyltetrazolium bromide assay. Intracellular localisation was mapped by confocal microscopy. Pgp expression was detected by immunofluorescence and Pgp function investigated by Rhodamine123 efflux on confocal microscopy. MTZ alone (0.1-0.2 microg ml(-1)) killed up to 89% of drug-sensitive cells; MDR cells exhibited less cytotoxicity (6-28%). Hypericin (0.1-0.2 microM) effects were similar for all cells; light illumination caused none or minimal toxicity. In combination, MTZ /hypericin plus illumination, potentiated MDR cell killing, vs hypericin or MTZ alone. (MGHU1/R: 38.65 and 36.63% increase, P<0.05; MCF-7/R: 80.2 and 46.1% increase, P<0.001). Illumination of combined MTZ/hypericin increased killing by 28.15% (P<0.05 MGHU1/R) compared to dark controls. Intracytoplasmic vesicular co-localisation of MTZ/hypericin was evident before illumination and at serial times post-illumination. MTZ was always found in sensitive cell nuclei, but not in dark resistant cell nuclei. In illuminated resistant cells there was some mobilisation of MTZ into the nucleus. Pgp expression remained unchanged, regardless of drug exposure. Pgp efflux was blocked by the Pgp inhibitor verapamil (positive control) but not impeded by hypericin. The increased killing of MDR cancer cells demonstrated is consistent with PCI. PCI is a promising technique for enhancing treatment efficacy. PMID:17667930

  19. Thin monocrystalline silicon solar cells

    Microsoft Academic Search

    K. A. Muenzer; Konstantin T. Holdermann; Reinhold E. Schlosser; Steffen Sterk

    1999-01-01

    One of the most effective approaches for a cost reduction of crystalline silicon solar cells is the better utilization of the crystals by cutting thinner wafers. However, such thin silicon wafers must have sufficient mechanical strength to maintain a high mechanical yield in cell and module manufacturing. The electrical performance of thin cells drops strongly with decreasing cell thickness if

  20. Transporting Solar-Cell Strings

    NASA Technical Reports Server (NTRS)

    Bycer, M.; Frasch, W.

    1982-01-01

    Vacuum "lance" picks up assembled chain of solar cells from string conveyor without disturbing cells or interconnecting tabs. Lance has 2 vacuum pickups per cell, for total of up to 32 pickups. Positions and number of pickups can be varied. Lance can be adjusted for range of cell sizes, shapes, and spacings.

  1. Solar Energy Materials & Solar Cells 90 (2006) 664677 Invited article

    E-print Network

    Romeo, Alessandro

    2006-01-01

    Solar Energy Materials & Solar Cells 90 (2006) 664­677 Invited article Recent developments in evaporated CdTe solar cells G. Khrypunova , A. Romeob , F. Kurdesauc , D.L. Ba¨ tznerd , H. Zogge , A Abstract Recent developments in the technology of high vacuum evaporated CdTe solar cells are reviewed

  2. Laser processing of solar cells

    NASA Astrophysics Data System (ADS)

    Carlson, David E.

    2012-10-01

    Laser processing has a long history in the manufacturing of solar cells since most thin-film photovoltaic modules have been manufactured using laser scribing for more than thirty years. Lasers have also been used by many solar cell manufacturers for a variety of applications such as edge isolation, identification marking, laser grooving for selective emitters and cutting of silicon wafers and ribbons. In addition, several laser-processing techniques are currently being investigated for the production of new types of high performance silicon solar cells. There have also been research efforts on utilizing laser melting, laser annealing and laser texturing in the fabrication of solar cells. Recently, a number of manufacturers have been developing new generations of solar cells where they use laser ablation of dielectric layers to form selective emitters or passivated rear point contacts. Others have been utilizing lasers to drill holes through the silicon wafers for emitter-wrap-through or metal-wrap-through back-contact solar cells. Scientists at Fraunhofer ISE have demonstrated high efficiency silicon solar cells (21.7%) by using laser firing to form passivated rear point contacts in p-type silicon wafers. Investigators art both the University of Stuttgart and the University of New South Wales have produced high efficiency silicon solar cells using laser doping to form selective emitters, and some companies are now developing commercial products based on both laser doping and laser firing of contacts. The use of lasers in solar cell processing appears destined to grow given the advances that are continually being made in laser technology.

  3. Enhanced efficacy of bleomycin in bladder cancer cells by photochemical internalization.

    PubMed

    Baglo, Yan; Hagen, Lars; Høgset, Anders; Drabløs, Finn; Otterlei, Marit; Gederaas, Odrun A

    2014-01-01

    Bleomycin is a cytotoxic chemotherapeutic agent widely used in cancer treatment. However, its efficacy in different cancers is low, possibly due to limited cellular internalization. In this study, a novel approach known as photochemical internalization (PCI) was explored to enhance bleomycin delivery in bladder cancer cells (human T24 and rat AY-27), as bladder cancer is a potential indication for use of PCI with bleomycin. The PCI technique was mediated by the amphiphilic photosensitizer disulfonated tetraphenyl chlorin (TPCS(2a)) and blue light (435?nm). Two additional strategies were explored to further enhance the cytotoxicity of bleomycin; a novel peptide drug ATX-101 which is known to impair DNA damage responses, and the protease inhibitor E-64 which may reduce bleomycin degradation by inhibition of bleomycin hydrolase. Our results demonstrate that the PCI technique enhances the bleomycin effect under appropriate conditions, and importantly we show that PCI-bleomycin treatment leads to increased levels of DNA damage supporting that the observed effect is due to increased bleomycin uptake. Impairing the DNA damage responses by ATX-101 further enhances the efficacy of the PCI-bleomycin treatment, while inhibiting the bleomycin hydrolase does not. PMID:25101299

  4. Enhanced Efficacy of Bleomycin in Bladder Cancer Cells by Photochemical Internalization

    PubMed Central

    Høgset, Anders; Otterlei, Marit; Gederaas, Odrun A.

    2014-01-01

    Bleomycin is a cytotoxic chemotherapeutic agent widely used in cancer treatment. However, its efficacy in different cancers is low, possibly due to limited cellular internalization. In this study, a novel approach known as photochemical internalization (PCI) was explored to enhance bleomycin delivery in bladder cancer cells (human T24 and rat AY-27), as bladder cancer is a potential indication for use of PCI with bleomycin. The PCI technique was mediated by the amphiphilic photosensitizer disulfonated tetraphenyl chlorin (TPCS2a) and blue light (435?nm). Two additional strategies were explored to further enhance the cytotoxicity of bleomycin; a novel peptide drug ATX-101 which is known to impair DNA damage responses, and the protease inhibitor E-64 which may reduce bleomycin degradation by inhibition of bleomycin hydrolase. Our results demonstrate that the PCI technique enhances the bleomycin effect under appropriate conditions, and importantly we show that PCI-bleomycin treatment leads to increased levels of DNA damage supporting that the observed effect is due to increased bleomycin uptake. Impairing the DNA damage responses by ATX-101 further enhances the efficacy of the PCI-bleomycin treatment, while inhibiting the bleomycin hydrolase does not. PMID:25101299

  5. The solar flare of 18 August 1979: Incoherent scatter radar data and photochemical model comparisons

    SciTech Connect

    Zinn, J.; Sutherland, C.D.; Fenimore, E.E.; Ganguly, S.

    1988-04-01

    Measurements of electron density at seven D-region altidues were made with the Arecibo radar during a Class-X solar flare on 18 August 1979. Measurements of solar x-ray fluxes during the same period were available from the GOES-2 satellite (0.5 to 4 /angstrom/ and 1 to 8 /angstrom/) and from ISEE-3 (in four bands between 26 and 400 keV). From the x-ray flux data we computed ionization rates in the D-region and the associated chemical changes, using a coupled atmospheric chemistry and diffusion model (with 836 chemical reactions and 19 vertical levels). The computed electron densities matched the data fairly well after we had adjusted the rate coefficients of two reactions. We discuss the hierarchies among the many flare-induced chemical reactions in two altitude ranges within the D-region and the effects of adjusting several other rate coefficients. 51 refs., 6 figs., 3 tabs.

  6. 24% efficient silicon solar cells

    Microsoft Academic Search

    Jianhua Zhao; Aihua Wang; Pietro P. Altermatt; Stuart R. Wenham; Marltin A. Green

    1994-01-01

    This paper reports significant progress in silicon solar cell performance, taking confirmed efficiency beyond 24% for the first time. This progress has been achieved by a combination of several mechanisms. One is the reduction of recombination at the cell front surface by improved passivation of the silicon\\/silicon dioxide interface. Resistive losses in the cell have been reduced by a double-plating

  7. Solar cell with back side contacts

    DOEpatents

    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.

  8. Radiation effects in solar cells

    NASA Astrophysics Data System (ADS)

    Imaizumi, Mitsuru; Ohshima, Takeshi

    2013-05-01

    Two types of space solar cells, silicon single-junction and InGaP/GaAs/Ge triple-junction (3J) solar cells, have been primarily adopted for spacecraft. The conversion efficiencies of the solar cells under AM0, 1 sun condition are ~17% for silicon and ~30% for 3J cells. Radiation degradation occurs in space due to high-energy electrons and protons existing in space environment. The degradation is caused by radiation induced crystal defects which act as minority-carrier recombination centers and majority-carrier trap centers. The 3J cells are superior radiation resistant to the silicon cells, and this is mainly because the InGaP top-subcell has property of very high radiation resistance.

  9. Research on multibandgap solar cells

    Microsoft Academic Search

    J. A. Cape; L. M. Fraas; P. S. McLeod; L. D. Partain

    1987-01-01

    This report describes research in multibandgap solar cells. In early work, two-color solar cells with efficiencies exceeding 20 percent were grown monolithically, comprising a GaAsP top junction over a GaAs or GaAsSb bottom junction. Researchers attempted to understand the effects of lattice mismatch and optimize growth conditions for these structures. Severe unreproducibility was encountered and traced to source material impurities.

  10. Multijunction amorphous silicon solar cells

    Microsoft Academic Search

    D. E. Carlson

    1991-01-01

    Thin-film multijunction solar cells have the potential to meet the performance and cost reauirements for grid-connected power generation. At present, multijunction amorphous silicon solar cells have exhibited stabilized conversion efficiencies of about 10% in the laboratory, and large-area modules of comparable performance should be available commercially by the mid-1990s. Further improvements in the properties of amorphous silicon alloys should lead

  11. Metabolic changes in the rat brain after a photochemical lesion treated by stem cell transplantation assessed by 1H MRS

    Microsoft Academic Search

    Vít Herynek; Kate?ina R?ži?ková; Pavla Jendelová; Eva Syková; Milan Hájek

    2009-01-01

    Object  Metabolite changes in an experimental lesion in the rat cortex and in the contralateral hemisphere after the intravenous administration\\u000a of mesenchymal stem cells (MSCs) were assessed by proton MR spectroscopy to verify the impact of the cell treatment on the\\u000a brain tissue.\\u000a \\u000a \\u000a \\u000a Materials and methods  Wistar rats with a photochemical cortical lesion and transplanted MSCs or sham transplanted rats were examined.

  12. Stable, high-efficiency amorphous silicon solar cells with low hydrogen content

    SciTech Connect

    Fortmann, C.M.; Hegedus, S.S. (Institute of Energy Conversion, Newark, DE (United States))

    1992-12-01

    Results and conclusions obtained during a research program of the investigation of amorphous silicon and amorphous silicon based alloy materials and solar cells fabricated by photo-chemical vapor and glow discharge depositions are reported. Investigation of the effects of the hydrogen content in a-si:H i-layers in amorphous silicon solar cells show that cells with lowered hydrogen content i-layers are more stable. A classical thermodynamic formulation of the Staebler-Wronski effect has been developed for standard solar cell operating temperatures and illuminations. Methods have been developed to extract a lumped equivalent circuit from the current voltage characteristic of a single junction solar cell in order to predict its behavior in a multijunction device.

  13. Dye-sensitized Solar Cells for Solar Energy Harvesting

    Microsoft Academic Search

    M. S. Roy; Y. S. Deol; Manish Kumar; Narottam Prasad; Yojana Janu

    2011-01-01

    Dye-sensitized solar cells (DSSCs) also known as Gratzel cells, have attracted the interests of researchers to a great extent because of its cost effective and easy manufacturing process without involving highly sophisticated lithographic technique and high cost raw materials as usually seen in conventional solar cell. Based on simple photo-electrochemical process, it has got immense potential in converting solar energy

  14. Simultaneous Light-Directed Synthesis of Mirror-Image Microarrays in a Photochemical Reaction Cell with Flare Suppression

    PubMed Central

    2013-01-01

    The use of photolabile protecting groups is a versatile and well-established means of synthesizing high complexity microarrays of biopolymers, such as nucleic acids and peptides, for high-throughput analysis. The synthesis takes place in a photochemical reaction cell which positions the microarray substrate at the focus of the optical system delivering the light and which can be connected to a fluidics system which delivers appropriate reagents to the surface in synchrony with the light exposure. Here we describe a novel photochemical reaction cell which allows for the simultaneous synthesis of microarrays on two substrates. The reaction cell positions both substrates within the limited depth-of-focus of the optical system while maintaining the necessary reagent flow conditions. The resulting microarrays are mirror images of each other but otherwise essentially identical. The new reaction cell doubles the throughput of microarray synthesis without increasing the consumption of reagents. In addition, a secondary flow chamber behind the reaction cell can be filled with an absorbent and index-matching fluid to eliminate reflections from light exiting the reaction cell assembly, greatly reducing unintended light exposure that reduces the sequence fidelity of the microarray probes. PMID:23968455

  15. Solar cells with a twist Comments ( 35)

    E-print Network

    Rogers, John A.

    Solar cells with a twist Article Comments ( 35) JULIE STEENHUYSEN REUTERS OCTOBER 7, 2008 AT 9:58 AM EDT CHICAGO -- U.S. researchers have found a way to make efficient silicon-based solar cells of buildings as opportunities for solar energy," Prof. Rogers said in a telephone interview. Solar cells, which

  16. Space solar cells—tradeoff analysis

    Microsoft Academic Search

    M. Raja Reddy

    2003-01-01

    This paper summarizes the study that had the objective to tradeoff space solar cells and solar array designs to determine the best choice of solar cell and array technology that would be more beneficial in terms of mass, area and cost for different types of space missions. Space solar cells, which are commercially now available in the market and to

  17. Gap/silicon Tandem Solar Cell with Extended Temperature Range

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A. (Inventor)

    2006-01-01

    A two-junction solar cell has a bottom solar cell junction of crystalline silicon, and a top solar cell junction of gallium phosphide. A three (or more) junction solar cell has bottom solar cell junctions of silicon, and a top solar cell junction of gallium phosphide. The resulting solar cells exhibit improved extended temperature operation.

  18. Design of a photochemical converter for solar energy using semiconductor electrodes

    SciTech Connect

    Ito, R.; Inoue, Y.; Hayamizu, M. (Osaka Univ., Osaka (Japan))

    1993-07-01

    The effects of the incident light intensity and the geometrical structure of a wet-type photoelectrochemical cell on its energy conversion efficiency are investigated. Increasing the surface area of the semiconductor electrodes increases the amount of incident light, but it also increases the ohmic resistance of the electrolyte between the electrodes due to the relative positions of the photoanode and counter electrode, and deforms the current-density distribution on the semiconductor electrodes. Increasing the thickness of the electrolyte layer between the incident wall and the semiconductor electrode reduces the absorption of the light rays by the electrolyte, but increases the ohmic resistance of the electrolyte between the electrodes. The design of a photoelectrochemical cell with a high energy-conversion efficiency, based on these findings, is described.

  19. Wide Band Gap Gallium Phosphide Solar Cells

    Microsoft Academic Search

    Xuesong Lu; Susan Huang; Martin B. Diaz; Nicole Kotulak; Ruiying Hao; Robert Opila; Allen Barnett

    2012-01-01

    Gallium phosphide (GaP), with its wide band gap of 2.26 eV, is a good candidate for the top junction solar cell in a multijunction solar cell system. Here, we design, fabricate, characterize, and analyze GaP solar cells. Liquid phase epitaxy is used to grow the semiconductor layers. Four generations of GaP solar cells are developed and fabricated with each solar

  20. Natural Variants of Photosystem II Subunit D1 Tune Photochemical Fitness to Solar Intensity*

    PubMed Central

    Vinyard, David J.; Gimpel, Javier; Ananyev, Gennady M.; Cornejo, Mario A.; Golden, Susan S.; Mayfield, Stephen P.; Dismukes, G. Charles

    2013-01-01

    Photosystem II (PSII) is composed of six core polypeptides that make up the minimal unit capable of performing the primary photochemistry of light-driven charge separation and water oxidation in all oxygenic phototrophs. The D1 subunit of this complex contains most of the ligating amino acid residues for the Mn4CaO5 core of the water-oxidizing complex (WOC). Most cyanobacteria have 3–5 copies of the psbA gene coding for at least two isoforms of D1, whereas algae and plants have only one isoform. Synechococcus elongatus PCC 7942 contains two D1 isoforms; D1:1 is expressed under low light conditions, and D1:2 is up-regulated in high light or stress conditions. Using a heterologous psbA expression system in the green alga Chlamydomonas reinhardtii, we have measured growth rate, WOC cycle efficiency, and O2 yield as a function of D1:1, D1:2, or the native algal D1 isoform. D1:1-PSII cells outcompete D1:2-PSII cells and accumulate more biomass in light-limiting conditions. However, D1:2-PSII cells easily outcompete D1:1-PSII cells at high light intensities. The native C. reinhardtii-PSII WOC cycles less efficiently at all light intensities and produces less O2 than either cyanobacterial D1 isoform. D1:2-PSII makes more O2 per saturating flash than D1:1-PSII, but it exhibits lower WOC cycling efficiency at low light intensities due to a 40% faster charge recombination rate in the S3 state. These functional advantages of D1:1-PSII and D1:2-PSII at low and high light regimes, respectively, can be explained by differences in predicted redox potentials of PSII electron acceptors that control kinetic performance. PMID:23271739

  1. Nanocrystal Solar Cells

    E-print Network

    Gur, Ilan

    2006-01-01

    extensive research on organic photovoltaic cells since smallcells with 3-dimensional hyperbranched nanocrystals 4.1 Introduction Early research in organic photovoltaicorganic heterojunction cell demonstrated almost 10 years prior (4). Photovoltaic cells

  2. Silicon concentrator solar cell research

    SciTech Connect

    Green, M.A.; Zhao, J.; Wang, A.; Dai, X.; Milne, A.; Cai, S.; Aberle, A.; Wenham, S.R. [Univ. of New South Wales, Kensington, NSW (AU). Centre for Photovoltaic Devices and Systems

    1993-06-01

    This report describes work conducted between December 1990 and May 1992 continuing research on silicon concentrator solar cells. The objectives of the work were to improve the performance of high-efficiency cells upon p-type substrates, to investigate the ultraviolet stability of such cells, to develop concentrator cells based on n-type substrates, and to transfer technology to appropriate commercial environments. Key results include the identification of contact resistance between boron-defused areas and rear aluminum as the source of anomalously large series resistance in both p- and n-type cells. A major achievement of the present project was the successful transfer of cell technology to both Applied Solar Energy Corporation and Solarex Corporation.

  3. PHOTOCHEMICAL PRODUCTS IN URBAN MIXTURES ENHANCE INFLAMMATORY RESPONSES IN LUNG CELLS

    EPA Science Inventory

    Complex urban air mixtures that realistically mimic urban smog can be generated for investigating adverse health effects. "Smog chambers" have been used for over 30 yr to conduct experiments for developing and testing photochemical models that predict ambient ozone (O(3)) concent...

  4. Atmospheric photochemical transformations enhance 1,3-butadiene-induced inflammatory responses in human epithelial cells: The role of ozone and other photochemical degradation products

    Microsoft Academic Search

    Melanie Doyle; Kenneth G. Sexton; Harvey Jeffries; Ilona Jaspers

    2007-01-01

    Chemistry of hazardous air pollutants has been studied for many years, yet little is known about how these chemicals, once reacted within urban atmospheres, affect healthy and susceptible individuals. Once released into the atmosphere, 1,3-butadiene (BD) reacts with hydroxyl radicals and ozone (created by photochemical processes), to produce many identified and unidentified products. Once this transformation has occurred, the toxic

  5. PHOTOCHEMICAL BOX MODEL (PBM)

    EPA Science Inventory

    This magnetic tape contains the FORTRAN source code, sample input data, and sample output data for the Photochemical Box Model (PBM). The PBM is a simple stationary single-cell model with a variable height lid designed to provide volume-integrated hour averages of O3 and other ph...

  6. Development of concentrator solar cells

    SciTech Connect

    Not Available

    1994-08-01

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

  7. (Melanin-Sensitized Solar Cell) : 696220016

    E-print Network

    the majority dye-sensitized solar cell research all uses the Ruthenium-complex as a light harvester. Dye-sensitized solar cell, DSSC 1991GrätzelDSSC[1] DSSCGrätzel cellDSSC polypyridyl complexes (Melanin-Sensitized Solar Cell) : : : 696220016 #12; #12;#12; #12;I PLD

  8. Photochemical bonding of epithelial cell-seeded collagen lattice to rat muscle layer for esophageal tissue engineering: a pilot study

    NASA Astrophysics Data System (ADS)

    Chan, Barbara P.; Sato, M.; Vacanti, Joseph P.; Kochevar, Irene E.; Redmond, Robert W.

    2005-04-01

    Bilayered tube structures consist of epithelial cell-seeded collagen lattice and muscle layer have been fabricated for esophageal tissue engineering. Good adhesion between layers in order to facilitate cell infiltration and neovascularization in the collagen lattice is required. Previous efforts include using other bioglues such as fibrin glue and silicone tube as the physical support. However, the former is subjected to chances of transmitting blood-born infectious disease and is time consuming while the latter requires a second surgical procedure. The current project aimed to bond the cell-seeded collagen lattice to muscle layer using photochemical bonding, which has previously been demonstrated a rapid and non-thermal procedure in bonding collagenous tissues. Rat esophageal epithelial cells were seeded on collagen lattice and together with the latissimus dorsi muscle layer, were exposed to a photosensitizer rose Bengal at the bonding surface. An argon laser was used to irradiate the approximated layers. Bonding strength was measured during the peeling test of the collagen layer from the muscle layer. Post-bonding cell viability was assessed using a modified NADH-diaphorase microassay. A pilot in vivo study was conducted by directly bonding the cell-seeded collagen layer onto the muscle flap in rats and the structures were characterized histologically. Photochemical bonding was found to significantly increase the adherence at the bonding interface without compromising the cell viability. This indicates the feasibility of using the technique to fabricate multi-layered structures in the presence of living cells. The pilot animal study demonstrated integration of the collagen lattice with the muscle layer at the bonding interface although the subsequent surgical manipulation disturbed the integration at some region. This means that an additional procedure removing the tube could be avoided if the approximation and thus the bonding are optimized. Cell infiltration and neovascularization were also evident demonstrating that direct bonding of engineered tissue structures in particular those with low processability such as collagen lattice to the host tissue is feasible.

  9. Printing efficient solar cells

    Microsoft Academic Search

    Ritesh Tipnis; Darin Laird

    2008-01-01

    As worldwide demand for fossil fuels depletes reserves, scien- tists are increasingly focused on generating alternative energy— especially if it can be produced cleanly and inexpensively. Hy- droelectric, solar, wind, nuclear, and biomass technologies are replacing coal, oil, and natural gas. Many of these new tech- nologies have similar costs. Yet the availability of materials or existing infrastructure can affect

  10. Chlorophyll-sensitized solar cells

    SciTech Connect

    Glenn, D.F.

    1984-01-01

    The photovoltaic properties of the green plant pigment chlorophyll-a (Chl-a) were investigated in photoelectrochemical and solid-state solar cells. Both types of cells utilized a thin film of Chl-a electrodeposited on a SnO/sub 2/ optically transparent electrode. Solid state cells were fabricated by vapor depositing a thin layer of metal on top of the Chl-a to produce a SnO/sub 2//Chl-a/metal sandwich cell. Photoelectrochemical cells were assembled by immersing the SnO/sub 2//Chl-a electrode in an aqueous electrolyte solution along with a counter electrode. Both types of Chl-a cells were generally characterized by a strong dependence of the photoactivity on the other cell components and a surprisingly large photovoltage. Photoelectrochemical cells of SnO/sub 2//Chl-a/aq. AlCl/sub 3/ were seen to produce photovoltages as high as 1.1 V and photocurrents of 1.1 ..mu..A/cm/sub 2/ while a solid state cell of SnO/sub 2//Chl-a/Al could produce 1.4 V and an initial photocurrent of 200 ..mu..A/cm/sup 2/. This photoactivity was strongly time dependent in both configurations. Despite this fact these cells are the most powerful Ch-a sensitized solar cells yet reported.

  11. Photon upconversion for thin film solar cells

    Microsoft Academic Search

    J. de Wild

    2012-01-01

    In this research one of the many possible methods to increase the efficiency of solar cells is described. The method investigated is based on adapting the solar light in such a way that the solar cell can convert more light into electricity. The part of the solar spectrum that is adapted is the part that cannot be absorbed by the

  12. Photon management in thin film solar cells

    Microsoft Academic Search

    C. Rockstuhl; S. Fahr; T. Paul; C. Menzel; F. Lederer; K. Bittkau; T. Beckers; R. Carius

    2009-01-01

    We analyze the absorption enhancement in single and tandem solar-cells comprising nanostructures that increase the path of the photons inside the solar cell. For this purpose we exploit different physical phenomena in different material systems.

  13. Key Physical Mechanisms in Nanostructured Solar Cells

    SciTech Connect

    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.

  14. Process of making solar cell module

    DOEpatents

    Packer, M.; Coyle, P.J.

    1981-03-09

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

  15. EE580 Solar Cells Todd J. Kaiser

    E-print Network

    Kaiser, Todd J.

    7/21/2010 1 EE580 ­ Solar Cells Todd J. Kaiser · Lecture 05 · P-N Junction 1Montana State University: Solar Cells Lecture 5: P-N Junction P-N Junction · Solar Cell is a large area P-N junction electron (hole) positive) 2Montana State University: Solar Cells Lecture 5: P-N Junction p-n Junction p n P

  16. Dye-sensitized solar cells

    Microsoft Academic Search

    Michael Grätzel

    2003-01-01

    The dye-sensitized solar cells (DSC) provides a technically and economically credible alternative concept to present day p–n junction photovoltaic devices. In contrast to the conventional systems where the semiconductor assume both the task of light absorption and charge carrier transport the two functions are separated here. Light is absorbed by a sensitizer, which is anchored to the surface of a

  17. Solar cell module assembly jig

    Microsoft Academic Search

    H. W. Ofarrell

    1966-01-01

    The invention relates to the manufacture of solar cell modules and more particularly to a jig for assembling, positioning and maintaining the components under resilient pressure, while the entire assembly and the jig is subjected to heat for simultaneously soldering all of the various circuit connections; as well as structurally bonding the layers into a strong light weight structure which

  18. Monolithic and mechanical multijunction space solar cells

    Microsoft Academic Search

    R. K. Jain; D. J. Flood

    1993-01-01

    High-efficiency, lightweight, radiation-resistant solar cells are essential to meet the large power requirements of future space missions. Single-junction cells are limited in efficiency. Higher cell efficiencies could be realized by developing multijunction, multibandgap solar cells. Monolithic and mechanically stacked tandem solar cells surpassing single-junction cell efficiencies have been fabricated. This article surveys the current status of monolithic and mechanically stacked

  19. PAPER www.rsc.org/pps | Photochemical & Photobiological Sciences Alteration of chromophoric dissolved organic matter by solar UV radiation

    E-print Network

    Sommaruga, Ruben

    ) on bacterial abundance, activity and community composition in a coastal lagoon of the Atlantic Ocean with high degradation is accelerated when this pool is exposed to UVR.6 In these ecosystems, the coupled photochemical and microbial degradation of CDOM is thought to be an important sink for organic carbon carried by rivers.7

  20. Silicon solar cells: Physical metallurgy principles

    Microsoft Academic Search

    Michael G. Mauk

    2003-01-01

    This article reviews the physical metallurgy aspects of silicon solar cells. The production of silicon solar cells relies\\u000a on principles of thermochemical extractive metallurgy, phase equilibria, solidification, and kinetics. The issues related\\u000a to these processes and their impact on solar cell performance and cost are discussed.

  1. Detailed balance analysis of nanophotonic solar cells

    E-print Network

    Fan, Shanhui

    -idealities, and is useful for determining the theoretical limit of solar cell efficiency for a given structure. Our approachDetailed balance analysis of nanophotonic solar cells Sunil Sandhu, Zongfu Yu, and Shanhui Fan-voltage characteristic modeling of nanophotonic solar cells. This approach takes into account the intrinsic material non

  2. EE580 Solar Cells Todd J. Kaiser

    E-print Network

    Kaiser, Todd J.

    7/21/2010 1 EE580 ­ Solar Cells Todd J. Kaiser · Lecture 04 · Semiconductor Materials · Chapter 1 1Montana State University: Solar Cells Lecture 4: Semiconductor Materials Semiconductor Bond Model · Bohr electrons interact to form bonds 2Montana State University: Solar Cells Lecture 4: Semiconductor Materials

  3. EE580 Solar Cells Todd J. Kaiser

    E-print Network

    Kaiser, Todd J.

    7/21/2010 1 EE580 ­ Solar Cells Todd J. Kaiser · Lecture 03 · Nature of Sunlight 1Montana State University: Solar Cells Lecture 3: Nature of Sunlight Wave-Particle Duality · Light acts as ­ Waves University: Solar Cells Lecture 3: Nature of Sunlight Properties of Light · Sunlight contains photons of many

  4. EE580 Solar Cells Todd J. Kaiser

    E-print Network

    Kaiser, Todd J.

    7/21/2010 1 EE580 ­ Solar Cells Todd J. Kaiser · Lecture 07 · EE Fundamentals 1Montana State University: Solar Cells Lecture 7: EE Fundamentals What is Electrical Engineering · Opposite of lightning · Symbolic information: electronics Montana State University: Solar Cells Lecture 7: EE Fundamentals 2 Review

  5. EE580 Solar Cells Todd J. Kaiser

    E-print Network

    Kaiser, Todd J.

    7/21/2010 1 EE580 ­ Solar Cells Todd J. Kaiser · Lecture 02 Microfabrication ­ A combination · Photolithograpy · Depostion · Etching 1 Montana State University: Solar Cells Lecture 2: Microfabrication Flow Montana State University: Solar Cells Lecture 2: Microfabrication Questions · What is heat? · Heat

  6. EE580 Solar Cells Todd J. Kaiser

    E-print Network

    Kaiser, Todd J.

    7/21/2010 1 EE580 ­ Solar Cells Todd J. Kaiser · Lecture 09 · Photovoltaic Systems 1Montana State University: Solar Cells Lecture 9: PV Systems Several types of operating modes · Centralized power plant or wanted Montana State University: Solar Cells Lecture 9: PV Systems 2 Residential Side Mounted Montana

  7. Texturisation of single crystalline silicon solar cell

    Microsoft Academic Search

    N. Johan; M. Mohamad Shahimin; S. Shaari

    2010-01-01

    The potential of solar cells have not been fully tapped due to lack of energy conversion efficiency. There are three importance mechanisms in producing high efficiency cells to harvest solar energy; reduction of reflectance, light trapping in the cell and higher light absorption. The work presented in this paper shows studies conducted in surface texturisation of single crystalline silicon solar

  8. Qualification of European nonreflective solar cells

    Microsoft Academic Search

    J. C. Larue

    1978-01-01

    Space environment and endurance tests were performed on 55 2 x 4 cm nonreflective (black) silicon solar cells. The qualification program followed the ESA standard specification for space solar cells. All tests were passed successfully. The average beginning of life maximum power of this type of solar cell reached 130 mW at 25 C while after irradiation with 10 to

  9. Solar cell array design handbook. Volume I

    Microsoft Academic Search

    Rauschenbach

    1976-01-01

    The Solar Cell Array Design Handbook is written at a practicing engineering level and provides a comprehensive compilation of explanatory notes, design practices, analytical models, solar cell characteristics, and material properties data of interest to personnel engaged in solar cell array performance specification, hardware design, analysis, fabrication and test. Twelve handbook chapters discuss the following: historical developments, the environment and

  10. Solar Cell Crack Inspection by Image Processing

    Microsoft Academic Search

    Fu Zhuang; Zhao Yanzheng; Liu Yang; Cao Qixin; Chen Mingbo; Zhang Jun; Jay Lee

    2009-01-01

    The aircraft works in space with terrible circumstance far from the Earth, so it is necessary for the solar cell with the property of anti-radiation to perform bonding process. After bonding, an essential process to the solar cell assembly is to inspect the cracks on the edge or inside of the solar cell. To avoid utilizing the unqualified products and

  11. Solar cell crack inspection by image processing

    Microsoft Academic Search

    Fu Zhuang; Zhao Yanzheng; Liu Yang; Cao Qixin; Chen Mingbo; Zhang Jun; Jay Lee

    2004-01-01

    Spacecraft operate in a hostile environment, far from the Earth, so it is necessary for solar cells with anti-radiation properties to have a bonding process carried out on them. After bonding, an essential process for the solar cell assembly is to inspect for cracks on the edges or inside the solar cell. To avoid utilizing unqualified products and to improve

  12. Predicted solar cell edge radiation effects

    Microsoft Academic Search

    Markland T. Gates

    1993-01-01

    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

  13. Flexibility in space solar cell production

    NASA Technical Reports Server (NTRS)

    Khemthong, Scott; Iles, Peter A.

    1989-01-01

    The wide range of cells that must be available from present-day production lines for space solar cells are described. After over thirty years of space-cell use, there is very little standardization in solar cell design. It is not generally recognized what a wide range of designs must remain available on cell production lines. This range of designs is surveyed.

  14. Photochemical reactions for commercial synthesis

    SciTech Connect

    Guillet, J. E.

    1985-06-25

    Photochemical reactions are conducted using floating polymer beads on the surface of a moving body of water. The polymer bead is impregnated with a reactant, floated on the water in direct sunlight so as to expose the reactant to solar radiation, collected at a downstream location, treated to remove product from the polymer, and then the bead can be recycled. The process can be used to collect and store solar energy in chemical form, or for conducting photochemical synthesis to produce useful chemical products.

  15. Nanostructured Materials for Solar Cells

    NASA Technical Reports Server (NTRS)

    Bailey, Sheila; Raffaelle, Ryne; Castro, Stephanie; Fahey, S.; Gennett, T.; Tin, P.

    2003-01-01

    The use of both inorganic and organic nanostructured materials in producing high efficiency photovoltaics is discussed in this paper. Recent theoretical results indicate that dramatic improvements in device efficiency may be attainable through the use of semiconductor quantum dots in an ordinary p-i-n solar cell. In addition, it has also recently been demonstrated that quantum dots can also be used to improve conversion efficiencies in polymeric thin film solar cells. A similar improvement in these types of cells has also been observed by employing single wall carbon nanotubes. This relatively new carbon allotrope may assist both in the disassociation of excitons as well as carrier transport through the composite material. This paper reviews the efforts that are currently underway to produce and characterize these nanoscale materials and to exploit their unique properties.

  16. NANO REVIEW Enhancing Solar Cell Efficiencies through 1-D Nanostructures

    E-print Network

    Chen, Junhong

    include dye-sensitized solar cells, quantum- dot-sensitized solar cells, and p-n junction solar cells their efficiencies more practical. Now the third-generation solar cells, such as dye-sensitized solar cells (DSSCsNANO REVIEW Enhancing Solar Cell Efficiencies through 1-D Nanostructures Kehan Yu Æ Junhong Chen

  17. New trends for solar cell development and recent progress of dye sensitized solar cells

    Microsoft Academic Search

    Hong Lin; Wen-li Wang; Yi-zhu Liu; Xin Li; Jian-bao Li

    2009-01-01

    This article reviews the new concepts and new trends of solar cell development. To increase the photoelectric conversion efficiency,\\u000a reduce the cost, and for application in a much broader field, thin film solar cell, flexible solar cell, and tandem solar\\u000a cell have become important subjects to be studied. As the representative of the solar cells of the third generation, the

  18. Mixed ternary heterojunction solar cell

    SciTech Connect

    Chen, W.S.; Stewart, J.M.

    1992-08-25

    A thin film heterojunction solar cell and a method of making it has a p-type layer of mixed ternary I-III-VI[sub 2] semiconductor material in contact with an n-type layer of mixed binary II-VI semiconductor material. The p-type semiconductor material includes a low resistivity copper-rich region adjacent the back metal contact of the cell and a composition gradient providing a minority carrier mirror that improves the photovoltaic performance of the cell. The p-type semiconductor material preferably is CuInGaSe[sub 2] or CuIn(SSe)[sub 2]. 8 figs.

  19. Interfaces in perovskite solar cells.

    PubMed

    Shi, Jiangjian; Xu, Xin; Li, Dongmei; Meng, Qingbo

    2015-06-01

    The interfacial atomic and electronic structures, charge transfer processes, and interface engineering in perovskite solar cells are discussed in this review. An effective heterojunction is found to exist at the window/perovskite absorber interface, contributing to the relatively fast extraction of free electrons. Moreover, the high photovoltage in this cell can be attributed to slow interfacial charge recombination due to the outstanding material and interfacial electronic properties. However, some fundamental questions including the interfacial atomic and electronic structures and the interface stability need to be further clarified. Designing and engineering the interfaces are also important for the next-stage development of this cell. PMID:25688549

  20. Biological solar cell

    NASA Astrophysics Data System (ADS)

    Seibert, M.; Janzen, A. F.

    1980-04-01

    Recent reports have demonstrated the possibility of employing photoactive, biological membrane components in photoelectrochemical cells. Present studies have led to the attachment of a much simpler biological complex, the bacterial photosynthetic reaction center isolated from Rhodopseudomonas sphaeroides, directly onto a SnO2 semiconductor electrode. Light induced photovoltages and photocurrents not attributable to Dember effects were observed in photoelectrochemical cells employing reaction center coated, SnO2 working electrodes. Such reaction center electrodes may serve as model systems for future organic photovoltaic devices.

  1. Towards stable silicon nanoarray hybrid solar cells

    NASA Astrophysics Data System (ADS)

    He, W. W.; Wu, K. J.; Wang, K.; Shi, T. F.; Wu, L.; Li, S. X.; Teng, D. Y.; Ye, C. H.

    2014-01-01

    Silicon nanoarray hybrid solar cells benefit from the ease of fabrication and the cost-effectiveness of the hybrid structure, and represent a new research focus towards the utilization of solar energy. However, hybrid solar cells composed of both inorganic and organic components suffer from the notorious stability issue, which has to be tackled before the hybrid solar cells could become a viable alternative for harvesting solar energy. Here we show that Si nanoarray/PEDOT:PSS hybrid solar cells with improved stability can be fabricated via eliminating the water inclusion in the initial formation of the heterojunction between Si nanoarray and PEDOT:PSS. The Si nanoarray hybrid solar cells are stable against rapid degradation in the atmosphere environment for several months without encapsulation. This finding paves the way towards the real-world applications of Si nanoarray hybrid solar cells.

  2. GaAs Solar Cell Radiation Handbook

    NASA Technical Reports Server (NTRS)

    Anspaugh, B. E.

    1996-01-01

    The handbook discusses the history of GaAs solar cell development, presents equations useful for working with GaAs solar cells, describes commonly used instrumentation techniques for assessing radiation effects in solar cells and fundamental processes occurring in solar cells exposed to ionizing radiation, and explains why radiation decreases the electrical performance of solar cells. Three basic elements required to perform solar array degradation calculations: degradation data for GaAs solar cells after irradiation with 1 MeV electrons at normal incidence; relative damage coefficients for omnidirectional electron and proton exposure; and the definition of the space radiation environment for the orbit of interest, are developed and used to perform a solar array degradation calculation.

  3. Towards stable silicon nanoarray hybrid solar cells

    PubMed Central

    He, W. W.; Wu, K. J.; Wang, K.; Shi, T. F.; Wu, L.; Li, S. X.; Teng, D. Y.; Ye, C. H.

    2014-01-01

    Silicon nanoarray hybrid solar cells benefit from the ease of fabrication and the cost-effectiveness of the hybrid structure, and represent a new research focus towards the utilization of solar energy. However, hybrid solar cells composed of both inorganic and organic components suffer from the notorious stability issue, which has to be tackled before the hybrid solar cells could become a viable alternative for harvesting solar energy. Here we show that Si nanoarray/PEDOT:PSS hybrid solar cells with improved stability can be fabricated via eliminating the water inclusion in the initial formation of the heterojunction between Si nanoarray and PEDOT:PSS. The Si nanoarray hybrid solar cells are stable against rapid degradation in the atmosphere environment for several months without encapsulation. This finding paves the way towards the real-world applications of Si nanoarray hybrid solar cells. PMID:24430057

  4. Intracellular photochemical reactions in the RPE cell exhibit a wavelength dependence that resembles the action spectrum of melanin

    NASA Astrophysics Data System (ADS)

    Glickman, Randolph D.; Vendal, Meena; Gonzalez, Mary Ann; Kumar, Neeru

    1999-06-01

    Melanosomes isolated from retinal pigment epithelial (RPE) cells support photochemical oxidation of cellular components when excited by visible light. These reactions have an action spectrum peaking between 450 and 500 nm. We now report that similar, wavelength-dependent reactions occur within intact RPE cells. The chemical probes, 2', 7'-dichlorofluorescein and dihydrorhodamine 123, are non-fluorescent when reduced and fluorescent when oxidized. Cultured bovine and baboon RPE cells were labeled with these probes, and then exposed to quantum-equivalent, 488, 514.5 or 647.1 nm emissions from Argon and Krypton ion CW lasers. The probes were isolated from the cells by solid phase extraction, and the amount of oxidized probe quantified by HPLC with fluorescence detection. Alternatively, cells were imaged with a fluorescence microscope. Images were acquired at various intervals after the cells were exposed to blue ((lambda) max equals 490 nm) and yellow ((lambda) max equals 582 nm) wavelengths derived from the microscope exciter lamp. The kinetics and amplitude of the fluorescence change in the cells were quantified with image processing software. Both types of experiments yielded the conclusion that blue-green wavelengths, on a quantal basis, most efficiently induced photo-oxidative stress in the pigmented cells. The microscopy also indicated that fluorescence was restricted to the cytoplasm. These findings are consistent with the involvement of melanosomes in photo- oxidative reactions.

  5. Solar cells Improved Hybrid Solar Cells via in situ UV Polymerization

    E-print Network

    Sibener, Steven

    Solar cells Improved Hybrid Solar Cells via in situ UV Polymerization Sanja Tepavcevic, Seth B-enhanced solar energy conversion. By using this simple in situ UV polymerization method that couples mobility of the photoactive layer can be enhanced. 1. Introduction Hybrid solar cells have been developed

  6. Biological solar cells

    NASA Astrophysics Data System (ADS)

    Seibert, M.; Janzen, A. F.

    Recent reports have demonstrated the possibility of employing photoactive, biological membrane components in photoelectrochemical cells. Such systems have produced small photovoltages and photocurrents. Present studies in the laboratories have led to the attachment of a much simpler biological complex, the bacterial photosynthetic reaction center isolated from Rhodopseudomonas sphaeroides, directly onto an SnO2 electrode. The light-induced primary charge separation processes which occur across the reaction center macromolecule have been coupled to the electrode, and in a two-electrode configuration photovoltages as high as 70 mV and photocurrents as high as 0.5 microamp/sq cm have been observed in an external circuit.

  7. Dye-Sensitized Solar Cells

    NSDL National Science Digital Library

    This lesson from The Lawrence Hall of Science was taught in spring 2012 and teaches students about nano and environmental technologies. Students will create "dye-sensitized solar cells (DSSC) using nano-crystalline titanium dioxide." This page includes links to the Source Articles for the Hands-on Module and Project Staff Write-ups of the Hands-on Module. Additionally, five documents provide lecture and lab materials for instructor use.

  8. in thin film solar cells

    Microsoft Academic Search

    M. Igalson; P. Zabierowski; A. Romeo; L. Stolt

    The interface states in TCO\\/CdS\\/CdTe and ZnO\\/CdS\\/Cu(In,Ga)Se2 photovoltaic devices has been studied by use of reverse-bias transient capacitance spectroscopy. Laplace transform analysis has been used in order to enhance a spectral resolution of the technique. It is shown, that the method yields useful information on the electronic characteristics of the heterointerface in the thin film solar cells. The conclusions include

  9. High Temperature Solar Cell Development

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

    The majority of satellites and near-earth probes developed to date have used photovoltaic arrays for power generation. If future mission 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. In this paper, we derive the optimum bandgap as a function of the operating temperature.

  10. Three-junction solar cell

    DOEpatents

    Ludowise, Michael J. (Cupertino, CA)

    1986-01-01

    A photovoltaic solar cell is formed in a monolithic semiconductor. The cell contains three junctions. In sequence from the light-entering face, the junctions have a high, a medium, and a low energy gap. The lower junctions are connected in series by one or more metallic members connecting the top of the lower junction through apertures to the bottom of the middle junction. The upper junction is connected in voltage opposition to the lower and middle junctions by second metallic electrodes deposited in holes 60 through the upper junction. The second electrodes are connected to an external terminal.

  11. A new filter that accurately mimics the solar UV-B spectrum using standard UV lamps: the photochemical properties, stabilization and use of the urate anion liquid filter.

    PubMed

    Sampath-Wiley, Priya; Jahnke, Leland S

    2011-02-01

    The physiological effects unique to solar ultraviolet (UV)-B exposure (280-315 nm) are difficult to accurately replicate in the laboratory. This study evaluates the effectiveness of the sodium urate anion in a liquid filter that yields a spectrum nearly indistinguishable from the solar UV-B spectrum while filtering the emissions of widely used UV-B lamps. The photochemical properties and stability of this filter are examined and weighed against a typical spectrum of ground-level solar UV-B radiation. To test the effectiveness of this filter, light-saturated photosynthetic oxygen evolution rates were measured following exposure to UV-B filtered either by this urate filter or the widely used cellulose acetate (CA) filter. The ubiquitous marine Chlorophyte alga Dunaliella tertiolecta was tested under identical UV-B flux densities coupled with ecologically realistic fluxes of UV-A and visible radiation for 6 and 12 h exposures. These results indicate that the urate-filtered UV-B radiation yields minor photosynthetic inhibition when compared with exposures lacking in UV-B. This is in agreement with published experiments using solar radiation. In sharp contrast, radiation filtered by CA filters produced large inhibition of photosynthesis. PMID:20955223

  12. Multi-junction solar cell device

    Microsoft Academic Search

    Daniel J. Friedman; John F. Geisz

    2007-01-01

    A multi-junction solar cell device (10) is provided. The multi-junction solar cell device (10) comprises either two or three active solar cells connected in series in a monolithic structure. The multi-junction device (10) comprises a bottom active cell (20) having a single-crystal silicon substrate base and an emitter layer (23). The multi-junction device (10) further comprises one or two subsequent

  13. Current-Enhanced Quantum Well Solar Cells

    Microsoft Academic Search

    Chao-Gang Lou; Qiang Sun; Jun Xu; Xiao-Bing Zhang; Wei Lei; Bao-Ping Wang; Wen-Jun Chen; Zai-Xiang Qiao

    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

  14. heat treatment for solar cells

    NASA Astrophysics Data System (ADS)

    Consonni, Vincent; Renet, Sébastien; Garnier, Jérôme; Gergaud, Patrice; Artús, Lluis; Michallon, Jérôme; Rapenne, Laetitia; Appert, Estelle; Kaminski-Cachopo, Anne

    2014-05-01

    CdTe is an important compound semiconductor for solar cells, and its use in nanowire-based heterostructures may become a critical requirement, owing to the potential scarcity of tellurium. The effects of the CdCl2 heat treatment are investigated on the physical properties of vertically aligned ZnO/CdTe core-shell nanowire arrays grown by combining chemical bath deposition with close space sublimation. It is found that recrystallization phenomena are induced by the CdCl2 heat treatment in the CdTe shell composed of nanograins: its crystallinity is improved while grain growth and texture randomization occur. The presence of a tellurium crystalline phase that may decorate grain boundaries is also revealed. The CdCl2 heat treatment further favors the chlorine doping of the CdTe shell with the formation of chlorine A-centers and can result in the passivation of grain boundaries. The absorption properties of ZnO/CdTe core-shell nanowire arrays are highly efficient, and more than 80% of the incident light can be absorbed in the spectral range of the solar irradiance. The resulting photovoltaic properties of solar cells made from ZnO/CdTe core-shell nanowire arrays covered with CuSCN/Au back-side contact are also improved after the CdCl2 heat treatment. However, recombination and trap phenomena are expected to operate, and the collection of the holes that are mainly photo-generated in the CdTe shell from the CuSCN/Au back-side contact is presumably identified as the main critical point in these solar cells.

  15. Lifetime analysis and degradation study of polymer solar cells

    NASA Astrophysics Data System (ADS)

    de Bettignies, Remi; Leroy, Jocelyne; Chambon, Sylvain; Firon, Muriel; Sentein, Carole; Sicot, Lionel; Lutsen, Laurence

    2004-11-01

    Though being much less efficient than silicon cells, organic solar cells exhibit a unique combination of interesting properties: low cost, flexibility, and the possibility of large surface coverage. Large progresses have been made over the last years using MDMO-PPV (Poly[2-methoxy-5-(3",7"-dimethyloctyloxy)-1,4-phenylenevinylene) reaching efficiencies of 2.9% and recently efficiencies over 3%, using poly(3-hexyl thiophene). A great deal of research however has still to be invested to improve the current state of the art. Among the main key-points to be addressed are namely the stability and lifetime of such devices. We are currently working on bulk heterojunction solar cells made from MDMO-PPV and PCBM (methano-fullerene[6,6]-phenyl C61-butyric acid methyl ester). Different batches of MDMO-PPV, originating from different synthesis modes (classical "Gilch" synthesis and "Sulphinyl" synthesis led by IMEC-IMOMEC) have been tested. Evolution of the power efficiency following continuous illumination (AM1.5, 80 mW.cm-2) was characterized under controlled atmosphere of nitrogen. In parallel, photodegradation studies are also investigated and electrical modeling is under way in order to get a better understanding of the relations between photochemical and electrical parameters of the diode that can be deduced from I/V curves.

  16. Lifetime analysis and degradation study of polymer solar cells

    NASA Astrophysics Data System (ADS)

    de Bettignies, Remi; Leroy, Jocelyne; Chambon, Sylvain; Firon, Muriel; Sentein, Carole; Sicot, Lionel; Lutsen, Laurence J.

    2004-09-01

    Though being much less efficient than silicon cells, organic solar cells exhibit a unique combination of interesting properties: low cost, flexibility, and the possibility of large surface coverage. Large progresses have been made over the last years using MDMO-PPV (Poly[2-methoxy-5-(3",7"-dimethyloctyloxy)-1,4-phenylenevinylene) reaching efficiencies of 2.9% and recently efficiencies over 3%, using poly(3-hexyl thiophene). A great deal of research however has still to be invested to improve the current state of the art. Among the main key-points to be addressed are namely the stability and lifetime of such devices. We are currently working on bulk heterojunction solar cells made from MDMO-PPV and PCBM (methano-fullerene[6,6]-phenyl C61-butyric acid methyl ester). Different batches of MDMO-PPV, originating from different synthesis modes (classical "Gilch" synthesis and "Sulphinyl" synthesis led by IMEC-IMOMEC) have been tested. Evolution of the power efficiency following continuous illumination (AM1.5, 80 mW.cm-2) was characterized under controlled atmosphere of nitrogen. In parallel, photodegradation studies are also investigated and electrical modeling is under way in order to get a better understanding of the relations between photochemical and electrical parameters of the diode that can be deduced from I/V curves.

  17. Eutectic Contact Inks for Solar Cells

    NASA Technical Reports Server (NTRS)

    Ross, B.

    1985-01-01

    Low-resistance electrical contacts formed on solar cells by melting powders of eutectic composition of semiconductor and dopant. Process improves cell performance without subjecting cell to processing temperatures high enough to degrade other characteristics.

  18. Photochemical reactions for commercial synthesis

    Microsoft Academic Search

    Guillet

    1985-01-01

    Photochemical reactions are conducted using floating polymer beads on the surface of a moving body of water. The polymer bead is impregnated with a reactant, floated on the water in direct sunlight so as to expose the reactant to solar radiation, collected at a downstream location, treated to remove product from the polymer, and then the bead can be recycled.

  19. Calculating the efficiency of dye sensitized solar cells with industry based silicon solar cells

    Microsoft Academic Search

    Komal Magsi; Emilia Macdonald; Leon Shterengas

    2010-01-01

    Our senior design project deal with two types of solar cell technologies: industry standard Si-based and the emerging one based on novel dye sensitized materials. Dye sensitized solar cells will be fabricated in a laboratory setting. FTIR and Raman microscopy will be used to study the surface make-up of the novel solar cells. A thin film flexible photovoltaic cell will

  20. Plasmonic antenna effects on photochemical reactions.

    PubMed

    Gao, Shuyan; Ueno, Kosei; Misawa, Hiroaki

    2011-04-19

    Efficient solar energy conversion has been vigorously pursued since the 1970s, but its large-scale implementation hinges on the availability of high-efficiency modules. For maximum efficiency, it is important to absorb most of the incoming radiation, which necessitates both efficient photoexcitation and minimal electron-hole recombination. To date, researchers have primarily focused on the latter difficulty: finding a strategy to effectively separate photoinduced electrons and holes. Very few reports have been devoted to broadband sunlight absorption and photoexcitation. However, the currently available photovoltaic cells, such as amorphous silicon, and even single-crystal silicon and sensitized solar cells, cannot respond to the wide range of the solar spectrum. The photoelectric conversion characteristics of solar cells generally decrease in the infrared wavelength range. Thus, the fraction of the solar spectrum absorbed is relatively poor. In addition, the large mismatch between the diffraction limit of light and the absorption cross-section makes the probability of interactions between photons and cell materials quite low, which greatly limits photoexcitation efficiency. Therefore, there is a pressing need for research aimed at finding conditions that lead to highly efficient photoexcitation over a wide spectrum of sunlight, particularly in the visible to near-infrared wavelengths. As characterized in the emerging field of plasmonics, metallic nanostructures are endowed with optical antenna effects. These plasmonic antenna effects provide a promising platform for artificially sidestepping the diffraction limit of light and strongly enhancing absorption cross-sections. Moreover, they can efficiently excite photochemical reactions between photons and molecules close to an optical antenna through the local field enhancement. This technology has the potential to induce highly efficient photoexcitation between photons and molecules over a wide spectrum of sunlight, from visible to near-infrared wavelengths. In this Account, we describe our recent work in using metallic nanostructures to assist photochemical reactions for augmenting photoexcitation efficiency. These studies investigate the optical antenna effects of coupled plasmonic gold nanoblocks, which were fabricated with electron-beam lithography and a lift-off technique to afford high resolution and nanometric accuracy. The two-photon photoluminescence of gold and the resulting nonlinear photopolymerization on gold nanoblocks substantiate the existence of enhanced optical field domains. Local two-photon photochemical reactions due to weak incoherent light sources were identified. The optical antenna effects support the unprecedented realization of (i) direct photocarrier injection from the gold nanorods into TiO(2) and (ii) efficient and stable photocurrent generation in the absence of electron donors from visible (450 nm) to near-infrared (1300 nm) wavelengths. PMID:21381706

  1. Energy Conversion: Nano Solar Cell

    NASA Astrophysics Data System (ADS)

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

    2009-09-01

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

  2. Photochemical degradation of chromophoric-dissolved organic matter exposed to simulated UV-B and natural solar radiation

    Microsoft Academic Search

    Yunlin Zhang; Mingliang Liu; Boqiang Qin; Sheng Feng

    2009-01-01

    Photochemical degradation of chromophoric-dissolved organic matter (CDOM) by UV-B radiation decreases CDOM absorption in the\\u000a UV region and fluorescence intensity, and alters CDOM composition. CDOM absorption, fluorescence, and the spectral slope indicating\\u000a the CDOM composition were studied using 0.22-?m-filtered samples of Meiliang Bay water from Lake Taihu that were exposed to\\u000a short-term (0–12 h) simulated UV-B radiation and long-term (0–12 days)

  3. Using cell-fractionation and photochemical crosslinking methods to determine the cellular binding site(s) of the antitumor drug DMP 840.

    PubMed

    Chatterjee, P K; Sternberg, N L

    1995-04-01

    In order to understand its mechanism of action we have begun an effort to better define the cellular target of action of the experimental antitumor agent DMP 840 (NSC D640430; (R,R)-2,2'-(1,2-ethanediylbis(imino-(1-methyl-2,1-ethanediyl)))-bi s(5- nitro-1H-benz(de)isoquinoline-1,3-(2H)-dione) dimethanesulfonate). Using a combination of gentle cell fractionation procedures and a previously unidentified photochemical crosslinking reaction, we have shown that after the drug is added to cultured Clone A cells, more than 80% of the drug that is found associated with cells partitions to the chromatin-containing structural framework of the cell and that the primary target after crosslinking with 360 nm light is DNA. While DMP 840 photoreacts quite efficiently with purified RNA in vitro, no photoattachment of the drug to RNA was observed in cells. In vitro photochemical studies also reveal that while GC-rich DNA is a preferred target for drug interaction, AT-rich DNA is more active in the photochemical crosslinking reaction. These results suggest that DMP 840 probably kills cells by interfering with DNA-metabolic processes, and that the drug and its derivatives are likely to be useful photoactive molecular probes for investigating higher order chromatin structures in cells. PMID:7740079

  4. A Surface-Controlled Solar Cell

    NASA Technical Reports Server (NTRS)

    Daud, T.; Crotty, G. T.

    1987-01-01

    Open-circuit voltage and cell efficiency increased. Proposed technique for controlling recombination velocity on solar-cell surfaces provides cells of increased efficiency and open-circuit voltage. In present cells, uncontrolled surface recombination velocity degrades opencircuit voltage and efficiency. In cell using proposed technique, transparent conducting layer, insulated from cell contacts, biased to enable variable control of surface recombination velocity.

  5. Bypass diode for a solar cell

    DOEpatents

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

    2012-03-13

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

  6. Ultrasonic Bonding of Solar-Cell Leads

    NASA Technical Reports Server (NTRS)

    Frasch, W.

    1984-01-01

    Rolling ultrasonic spot-bonding method successfully joins aluminum interconnect fingers to silicon solar cells with copper metalization. Technique combines best features of ultrasonic rotary seam welding and ultrasonic spot bonding: allows fast bond cycles and high indexing speeds without use of solder or flux. Achieves reliable bonds at production rates without damage to solar cells. Bonding system of interest for all solar-cell assemblies and other assemblies using flat leads (rather than round wires).

  7. Solar Cell Modules With Improved Backskin

    DOEpatents

    Gonsiorawski, Ronald C. (Danvers, MA)

    2003-12-09

    A laminated solar cell module comprises a front light transmitting support, a plurality of interconnected solar cells encapsulated by a light-transmitting encapsulant material, and an improved backskin formed of an ionomer/nylon alloy. The improved backskin has a toughness and melting point temperature sufficiently great to avoid any likelihood of it being pierced by any of the components that interconnect the solar cells.

  8. Nanowire-based All Oxide Solar Cells

    Microsoft Academic Search

    Benjamin D. Yuhas; Peidong; Peidong Yang

    2008-01-01

    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

  9. Changes in photochemically significant solar UV spectral irradiance as estimated by the composite Mg II index and scale factors

    NASA Technical Reports Server (NTRS)

    Deland, Matthew T.; Cebula, Richard P.

    1994-01-01

    Quantitative assessment of the impact of solar ultraviolet irradiance variations on stratospheric ozone abundances currently requires the use of proxy indicators. The Mg II core-to-wing index has been developed as an indicator of solar UV activity between 175-400 nm that is independent of most instrument artifacts, and measures solar variability on both rotational and solar cycle time scales. Linear regression fits have been used to merge the individual Mg II index data sets from the Nimbus-7, NOAA-9, and NOAA-11 instruments onto a single reference scale. The change in 27-dayrunning average of the composite Mg II index from solar maximum to solar minimum is approximately 8 percent for solar cycle 21, and approximately 9 percent for solar cycle 22 through January 1992. Scaling factors based on the short-term variations in the Mg II index and solar irradiance data sets have been developed to estimate solar variability at mid-UV and near-UV wavelengths. Near 205 nm, where solar irradiance variations are important for stratospheric photo-chemistry and dynamics, the estimated change in irradiance during solar cycle 22 is approximately 10 percent using the composite Mg II index and scale factors.

  10. Laser-assisted solar cell metallization processing

    NASA Technical Reports Server (NTRS)

    Rohatgi, A.; Gupta, S.; Mcmullin, P. G.; Palaschak, P. A.

    1985-01-01

    Laser-assisted processing techniques for producing high-quality solar cell metallization patterns are being investigated, developed, and characterized. The tasks comprising these investigations are outlined.

  11. Improved monolithic tandem solar cell

    SciTech Connect

    Wanlass, M.W.

    1991-04-23

    A single-crystal, monolithic, tandem, photovoltaic solar cell is described which includes (a) an InP substrate having upper and lower surfaces, (b) a first photoactive subcell on the upper surf ace of the InP substrate, (c) a second photoactive subcell on the first subcell; and (d) an optically transparent prismatic cover layer over the second subcell. The first photoactive subcell is GaInAsP of defined composition. The second subcell is InP. The two subcells are lattice matched.

  12. Current and lattice matched tandem solar cell

    DOEpatents

    Olson, Jerry M. (Lakewood, CO)

    1987-01-01

    A multijunction (cascade) tandem photovoltaic solar cell device is fabricated of a Ga.sub.x In.sub.1-x P (0.505.ltoreq.X.ltoreq.0.515) top cell semiconductor lattice matched to a GaAs bottom cell semiconductor at a low-resistance heterojunction, preferably a p+/n+ heterojunction between the cells. The top and bottom cells are both lattice matched and current matched for high efficiency solar radiation conversion to electrical energy.

  13. Radiation damage in biomimetic dye molecules for solar cells

    NASA Astrophysics Data System (ADS)

    Cook, Peter L.; Johnson, Phillip S.; Liu, Xiaosong; Chin, An-Li; Himpsel, F. J.

    2009-12-01

    A significant obstacle to organic photovoltaics is radiation damage, either directly by photochemical reactions or indirectly via hot electrons. Such effects are investigated for biomimetic dye molecules for solar cells (phthalocyanines) and for a biological analog (the charge transfer protein cytochrome c). Both feature a central transition metal atom (or H2) surrounded by nitrogen atoms. Soft x-ray absorption spectroscopy and photoelectron spectroscopy are used to identify three types of radiation-induced changes in the electronic structure of these molecules. (1) The peptide bonds along the backbone of the protein are readily broken, while the nitrogen cage remains rather stable in phthalocyanines. This finding suggests minimizing peptide attachments to biologically inspired molecules for photovoltaic applications. (2) The metal atom in the protein changes its 3d electron configuration under irradiation. (3) The Fermi level EF shifts relative to the band gap in phthalocyanine films due to radiation-induced gap states. This effect has little influence on the optical absorption, but it changes the lineup between the energy levels of the absorbing dye and the acceptor/donor electrodes that collect the charge carriers in a solar cell.

  14. Detailed balance theory of excitonic and bulk heterojunction solar cells

    Microsoft Academic Search

    Thomas Kirchartz; Julian Mattheis; Uwe Rau

    2008-01-01

    A generalized solar cell model for excitonic and classical bipolar solar cells describes the combined transport and interaction of electrons, holes, and excitons in accordance with the principle of detailed balance. Conventional inorganic solar cells, single-phase organic solar cells and bulk heterojunction solar cells, i.e., nanoscale mixtures of two organic materials, are special cases of this model. For high mobilities,

  15. Front contact solar cell with formed emitter

    DOEpatents

    Cousins, Peter John (Menlo Park, CA)

    2012-07-17

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

  16. Silicon solar cells as a high-solar-intensity radiometer

    NASA Technical Reports Server (NTRS)

    Spisz, E. W.; Robson, R. R.

    1971-01-01

    The characteristics of a conventional, 1- by 2-cm, N/P, gridded silicon solar cell when used as a radiometer have been determined for solar intensity levels to 2800 mW/sq cm (20 solar constants). The short-circuit current was proportional to the radiant intensity for levels only to 700 mW/sq cm (5 solar constants). For intensity levels greater than 700 mW/sq cm, it was necessary to operate the cell in a photoconductive mode in order to obtain a linear relation between the measured current and the radiant intensity. When the solar cell was biased with a reverse voltage of -1 V, the measured current and radiant intensity were linearly related over the complete intensity range from 100 to 2800 mW/sq cm.

  17. Multiple quantum well top cells for multijunction concentrator solar cells

    Microsoft Academic Search

    Kan-Hua Lee; Keith W. J. Barnham; Benjamin C. Browne; James P. Connolly; Jessica G. J. Adams; Rob J. Airey; Nicholas J. Ekins-Daukes; Markus Fuhrer; Victoria Rees; Mathew Lumb; Alison L. Dobbin; Massimo Mazzer; John S. Roberts; Thomas N. D. Tibbits

    2011-01-01

    High efficiency quantum well GaAs solar cells have been successfully applied in commercial multijunction concentrator cells to increase the absorption in the infrared and provide variability of the absorption edge to optimise energy harvesting. Multiple quantum well (MQW) top cells can further improve the performance of multijunction solar cells since the absorption edge of top and middle subcells can be

  18. The Case for the Large Scale Development of Solar Energy

    ERIC Educational Resources Information Center

    O'Reilly, S. A.

    1977-01-01

    Traces the history of solar energy development. Discusses global effects (temperature, particle and other pollution) of burning fossil fuels. Provides energy balance equations for solar energy distribution and discusses flat plate collectors, solar cells, photochemical and photobiological conversion of solar energy, heat pumps. (CS)

  19. Ultrathin silicon solar cell for space application

    NASA Astrophysics Data System (ADS)

    Matsutani, T.; Saga, T.; Ueyama, H.; Hagihara, Y.; Hirano, T.; Suzuki, A.

    1982-01-01

    Ultrathin silicon (Si) solar cells for space application were fabricated on an experimental basis and the electrical characteristics were investigated for three kinds of cells (Black, BSFR and Conventional cells). Under 135.3 mW sq cm (AM0) illumination, ultrathin Black cells showed 67.7 mW output, which is equal to 89 percent output of 280 micron Black cells. The power to mass ratio of bare ultrathin Black cells was 3.6 times high compared with 280 micron thick Black cells. 1 MeV electron irradiation test was carried out to evaluate the radiation resistance. Ultrathin cells showed superior radiation resistance compared with that of 280 micron thick cells, and it was comparable to that of a GaAs solar cell which had been recognized as a radiation resistive cell. The results suggest that ultrathin solar cells have high potential for space application.

  20. Flexible solid-state dye solar cells

    Microsoft Academic Search

    Toby B. Meyer; Andreas F. Meyer; Daniel Ginestoux

    2002-01-01

    The cell structure concepts and materials to build solid-state dye solar cells based on nanocristalline titanium oxide and an organic hole conductor were investigated. The substrate cell is based on a metal foil and a semi-transparent gold window on top of the cell structure and the superstrate cell is deposited on ITO coated polymer foil replacing the traditional conductive glass

  1. Bonder for Solar-Cell Strings

    NASA Technical Reports Server (NTRS)

    Garwood, G.; Frasch, W.

    1982-01-01

    String bonder for solar-cell arrays eliminates tedious manual assembly procedure that could damage cell face. Vacuum arm picks up face-down cell from cell-inverting work station and transfers it to string conveyor without changing cell orientation. Arm is activated by signal from microprocessor.

  2. Organic Tandem Solar Cells: Design and Formation

    NASA Astrophysics Data System (ADS)

    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 polyelectrolyte layer functioning as the surface dipole formation layer to provide better electrical contact with the photoactive layer. Due to the effectiveness of the conjugated polyelectrolyte layer, performance improvement was also observed. Furthermore, other issues regarding the semi-transparent tandem solar cells (e.g., photocurrent matching, exterior color tuning, and transparency tuning) are all explored to optimize best performance. In Chapter 5 and 6, the architectures of double- and triple-junction tandem solar cells are explored. Theoretically, triple-junction tandem solar cells with three photoactive absorbers with cascaded energy bandgaps have the potential to achieve higher performance, in comparison with double-junction tandem solar cells. Such expectations can be ascribed to the minimized carrier thermalization loss and further improved light absorption. However, the design of triple-junction solar cells often involves sophisticated multiple layer deposition as well as substantial optimization. Therefore, there is a lack of successful demonstrations of triple-junction solar cells outperforming the double-junction counterparts. To solve the incompatible issues related to the layer deposition in the fabrication, we proposed a novel architecture of inverted-structure tandem solar cells with newly designed interconnecting layers. Our design of interconnecting layers does not only focus on maintaining the orthogonal solution processing advantages, but also provides an excellent compatibility in the energy level alignment to allow different absorber materials to be used. Furthermore, we also explored the light management inside the double- and triple-junction tandem solar cells. The study of light management was carried out through optical simulation method based transfer matrix formalism. The intention is to obtain a balanced photocurrent output from each subcells inside the tandem solar cell, thus the minimal recombination loss at the contact of interconnecting layers and the optimal efficiency can be expected. With help from simulations, we were able to ca

  3. Nanoparticle Solar Cell Final Technical Report

    Microsoft Academic Search

    Breeze; J Alison; Yudhisthira Sahoo; Damoder Reddy; Veronica Sholin; Sue Carter

    2008-01-01

    The purpose of this work was to demonstrate all-inorganic nanoparticle-based solar cells with photovoltaic performance extending into the near-IR region of the solar spectrum as a pathway towards improving power conversion efficiencies. The field of all-inorganic nanoparticle-based solar cells is very new, with only one literature publication in the prior to our project. Very little is understood regarding how these

  4. Monolithic cells for solar fuels.

    PubMed

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

    2014-12-01

    Hybrid energy generation models based on a variety of alternative energy supply technologies are considered the best way to cope with the depletion of fossil energy resources and to limit global warming. One of the currently missing technologies is the mimic of natural photosynthesis to convert carbon dioxide and water into chemical fuel using sunlight. This idea has been around for decades, but artificial photosynthesis of organic molecules is still far away from providing real-world solutions. The scientific challenge is to perform in an efficient way the multi-electron transfer reactions of water oxidation and carbon dioxide reduction using holes and single electrons generated in an illuminated semiconductor. In this tutorial review the design of photoelectrochemical (PEC) cells that combine solar water oxidation and CO2 reduction is discussed. In such PEC cells simultaneous transport and efficient use of light, electrons, protons and molecules has to be managed. It is explained how efficiency can be gained by compartmentalisation of the water oxidation and CO2 reduction processes by proton exchange membranes, and monolithic concepts of artificial leaves and solar membranes are presented. Besides transferring protons from the anode to the cathode compartment the membrane serves as a molecular barrier material to prevent cross-over of oxygen and fuel molecules. Innovative nano-organized multimaterials will be needed to realise practical artificial photosynthesis devices. This review provides an overview of synthesis techniques which could be used to realise monolithic multifunctional membrane-electrode assemblies, such as Layer-by-Layer (LbL) deposition, Atomic Layer Deposition (ALD), and porous silicon (porSi) engineering. Advances in modelling approaches, electrochemical techniques and in situ spectroscopies to characterise overall PEC cell performance are discussed. PMID:24526085

  5. Effects of contamination on solar cell coverglass

    Microsoft Academic Search

    D. L. Liu; S. H. Liu; C. J. Panetta; K. R. Olson; S. M. Hong; D. R. Alaan; C. J. Mann; K. T. Luey

    2010-01-01

    As the power generation capability of solar cells depends strongly on the spectra of the incident light through the coverglass, there is a critical need to understand the impact of adsorbed molecular (organic) contaminants, which absorb light in the short wavelength range. The goal of this work is to calculate solar cell current loss based on experimentally determined coverglass transmission

  6. Stability\\/degradation of polymer solar cells

    Microsoft Academic Search

    Mikkel Jørgensen; Kion Norrman; Frederik C. Krebs

    2008-01-01

    Polymer and organic solar cells degrade during illumination and in the dark. This is in contrast to photovoltaics based on inorganic semiconductors such as silicon. Long operational lifetimes of solar cell devices are required in real-life application and the understanding and alleviation of the degradation phenomena are a prerequisite for successful application of this new and promising technology. In this

  7. Report on high intensity solar cells

    SciTech Connect

    Schwartz, R.J.; Gray, J.L.; Lundstrom, M.S.

    1985-02-01

    Much effort has been directed recently toward the development of high efficiency solar cells for terrestrial use. Significant progress has been made for their use as an alternative to more conventional energy sources. Silicon solar cells in particular are rapidly approaching theoretical limitations in efficiency. To aid the development of more efficient solar cells, a mathematical model would be invaluable. Solar cell geometries could be compared and optimized before actual fabrication, eliminating problems caused by the uncertainties associated with device processing. Because analytic models require too many simplifying assumptions, numerical models must be used. Further, a two-dimensional model is needed because most solar cell geometries cannot be handled adequately in one dimension. A computer program, SCAP2D (Solar Cell Analysis Program in 2 Dimensions), capable of modeling a variety of solar cell structures under various operating conditions has been developed. The potential of this program for use as a design and analysis tool has been demonstrated by modeling the conventional, IBC, and EMVJ solar cells.

  8. Method of manufacture of solar cell panel

    Microsoft Academic Search

    J. S. Walker; W. C. Kittler

    1978-01-01

    There is described a solar cell panel consisting of an outer rigid transparent faceply of glass or plastic material to which are applied at least two layers of plastic such as polyvinyl butyral between which are positioned a plurality of solar cell wafers. A thin flexible film of polyethylene terephthalate forms the other outer surface of the panel. The panel

  9. Porous silicon in solar cells technology

    Microsoft Academic Search

    T. V. Semikina; A. N. Shmyryeva

    1998-01-01

    A construction and technology preparing of solar cells elements with distributed potential barriers and fitting nonuniforming distribution of diffusing impurities along thickness by porous silicon layer using are represented. The porous silicon process formation has been got. Optimizal regimes of short-circuit current increasing (on 58 %) and open voltage — (on 7 %) were determined for solar cells with porous

  10. A Simplified Solar Cell Array Modelling Program

    Microsoft Academic Search

    R. D. Hughes

    1982-01-01

    As part of the energy conversion\\/self sufficiency efforts of DSN engineering, it was necessary to have a simplified computer model of a solar photovoltaic (PV) system. This article describes the analysis and simplifications employed in the development of a PV cell array computer model. The analysis of the incident solar radiation, steady state cell temperature and the current-voltage characteristics of

  11. Modeling and simulation of organic solar cells

    Microsoft Academic Search

    Liming Liu; Guangyong Li

    2010-01-01

    We present our investigation of organic solar cells by modeling and simulation after numerically solving Poisson and continuity equations that describe the electric property of semiconductors. Specifically, simulations reveal that Langevin type recombination, which describes the loss mechanism in pristine materials with low mobility, is not proper to predict the performance of BHJ organic solar cells and will lead counterintuitive

  12. Thin solar cell and lightweight array

    NASA Technical Reports Server (NTRS)

    Brandhorst, Henry W., Jr. (inventor); Weinberg, Irving (inventor)

    1991-01-01

    A thin, lightweight solar cell that utilizes front contact metallization is presented. Both the front light receiving surface of the solar cell and the facing surface of the cover glass are recessed to accommodate this metallization. This enables the two surfaces to meet flush for an optimum seal.

  13. Black and thin silicon solar cells

    Microsoft Academic Search

    J. Michel

    1976-01-01

    Methods for reducing the cost of solar electricity obtained from P\\/N junction single crystal silicon photocells are discussed. In particular, the use of a cheap etching bath (KOH) for texturizing black solar cells, and the possibility of producing efficient cells with silicon layers in the 70 to 300 micron range are considered. A computer program capable of analyzing energy conversion

  14. Improved radiation hardness of silicon solar cells

    Microsoft Academic Search

    Hidetoshi Washio; Yoshifumi Tonomura; Minoru Kaneiwa; Tatsuo Saga; O. Anzawa; S. Matsuda

    2000-01-01

    SHARP and NASDA (National Space Development Agency of Japan) have been engaged in the development of silicon space solar cells since 1970s. We started the project to improve the radiation hardness of silicon solar cells in 1998. This project gave fruitful results in BJ (both-side junction) and AHES (advanced high efficiency silicon) structure. The design and manufacturing process for the

  15. Introduction to basic solar cell measurements

    NASA Technical Reports Server (NTRS)

    Brandhorst, H. W., Jr.

    1976-01-01

    The basic approaches to solar cell performance and diagnostic measurements are described. The light sources, equipment for I-V curve measurement, and the test conditions and procedures for performance measurement are detailed. Solar cell diagnostic tools discussed include analysis of I-V curves, series resistance and reverse saturation current determination, spectral response/quantum yield measurement, and diffusion length/lifetime determination.

  16. Terrestrial solar spectra, solar simulation and solar cell short-circuit current calibration - A review

    NASA Astrophysics Data System (ADS)

    Matson, R. J.; Emery, K. A.; Bird, R. E.

    1984-03-01

    In this paper, the main issues in modeling and measuring terrestrial solar spectra and their relation to the short-circuit current of solar cells are addressed. These issues are (1) the measured and modeled terrestrial solar spectra, (2) the optimal light sources and their filtering for simulating the standard terrestrial solar irradiance spectrum and (3) the consequences of a mismatch between the chosen standard terrestrial solar spectrum and the actual irradiance conditions for the rated efficiency of a solar cell. In addition, this review provides the photovoltaics community with a tutorial document and a summary of the current activities and results in this field.

  17. Nanowire-based All Oxide Solar Cells

    SciTech Connect

    Yang*, Benjamin D. Yuhas and Peidong; Yang, Peidong

    2008-12-07

    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 enhanced with the addition of an intermediate oxide insulating layer between the nanowires and the nanoparticles. This observation of the important dependence of the shunt resistance on the photovoltaic performance is widely applicable to any nanowire solar cell constructed with the nanowire array in direct contact with one electrode.

  18. High-Temperature Solar Cell Development

    NASA Technical Reports Server (NTRS)

    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.

  19. Coating Processes Boost Performance of Solar Cells

    NASA Technical Reports Server (NTRS)

    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.

  20. Silicon film solar cell process

    NASA Technical Reports Server (NTRS)

    Hall, R. B.; Mcneely, J. B.; Barnett, A. M.

    1984-01-01

    The most promising way to reduce the cost of silicon in solar cells while still maintaining performance is to utilize thin films (10 to 20 microns thick) of crystalline silicon. The method of solution growth is being employed to grow thin polycrystalline films of silicon on dissimilar substrates. The initial results indicate that, using tin as the solvent, this growth process only requires operating temperatures in the range of 800 C to 1000 C. Growth rates in the range of 0.4 to 2.0 microns per minute and grain sizes in the range of 20 to 100 microns were achieved on both quartz and coated steel substrates. Typically, an aspect ratio of two to three between the width and the Si grain thickness is seen. Uniform coverage of Si growth on quartz over a 2.5 x 2.5 cm area was observed.

  1. Non-photochemical chlorophyll fluorescence quenching and structural rearrangements induced by low pH in intact cells of Chlorella fusca (Chlorophyceae) and Mantoniella squamata (Prasinophyceae)

    Microsoft Academic Search

    Reimund Goss; Gyözö Garab

    2001-01-01

    We have used circular dichroism (CD) spectroscopy and chlorophyll fluorescence induction measurements in order to examine\\u000a low-pH-induced changes in the chiral macro-organization of the chromophores and in the efficiency of non-photochemical quenching\\u000a of the chlorophyll a fluorescence (NPQ) in intact, dark-adapted cells of Chlorella fusca (Chlorophyceae) and Mantoniella squamata (Prasinophyceae). We found that: (i) high proton concentrations enhanced the formation

  2. Eradication of p53-Mutated Head and Neck Squamous Cell Carcinoma Xenografts Using Nonviral p53 Gene Therapy and Photochemical Internalization

    Microsoft Academic Search

    Alioune Ndoye; Gilles Dolivet; Anders Høgset; Agnès Leroux; Alexandre Fifre; Patrick Erbacher; Kristian Berg; Jean-Paul Behr; François Guillemin; Jean-Louis Merlin

    2006-01-01

    Photochemical internalization (PCI) technology has been used for PEI-mediated p53 gene transfer in mice bearing head and neck squamous cell carcinoma (HNSCC) xenografts. Using luciferase as a reporter gene, PCI led to a 20-fold increase in transgene expression 48 h after transfection and sustained transgene expression for 7 days. Therefore, iterative p53 gene transfer was performed by means of a

  3. Porphyrin-sensitized solar cells.

    PubMed

    Li, Lu-Lin; Diau, Eric Wei-Guang

    2013-01-01

    Nature has chosen chlorophylls in plants as antennae to harvest light for the conversion of solar energy in complicated photosynthetic processes. Inspired by natural photosynthesis, scientists utilized artificial chlorophylls - the porphyrins - as efficient centres to harvest light for solar cells sensitized with a porphyrin (PSSC). After the first example appeared in 1993 of a porphyrin of type copper chlorophyll as a photosensitizer for PSSC that achieved a power conversion efficiency of 2.6%, no significant advance of PSSC was reported until 2005; beta-linked zinc porphyrins were then reported to show promising device performances with a benchmark efficiency of 7.1% reported in 2007. Meso-linked zinc porphyrin sensitizers in the first series with a push-pull framework appeared in 2009; the best cell performed comparably to that of a N3-based device, and a benchmark 11% was reported for a porphyrin sensitizer of this type in 2010. With a structural design involving long alkoxyl chains to envelop the porphyrin core to suppress the dye aggregation for a push-pull zinc porphyrin, the PSSC achieved a record 12.3% in 2011 with co-sensitization of an organic dye and a cobalt-based electrolyte. The best PSSC system exhibited a panchromatic feature for light harvesting covering the visible spectral region to 700 nm, giving opportunities to many other porphyrins, such as fused and dimeric porphyrins, with near-infrared absorption spectral features, together with the approach of molecular co-sensitization, to enhance the device performance of PSSC. According to this historical trend for the development of prospective porphyrin sensitizers used in PSSC, we review systematically the progress of porphyrins of varied kinds, and their derivatives, applied in PSSC with a focus on reports during 2007-2012 from the point of view of molecular design correlated with photovoltaic performance. PMID:23023240

  4. Semiconductor quantum dot-sensitized solar cells

    PubMed Central

    Tian, Jianjun; Cao, Guozhong

    2013-01-01

    Semiconductor quantum dots (QDs) have been drawing great attention recently as a material for solar energy conversion due to their versatile optical and electrical properties. The QD-sensitized solar cell (QDSC) is one of the burgeoning semiconductor QD solar cells that shows promising developments for the next generation of solar cells. This article focuses on recent developments in QDSCs, including 1) the effect of quantum confinement on QDSCs, 2) the multiple exciton generation (MEG) of QDs, 3) fabrication methods of QDs, and 4) nanocrystalline photoelectrodes for solar cells. We also make suggestions for future research on QDSCs. Although the efficiency of QDSCs is still low, we think there will be major breakthroughs in developing QDSCs in the future. PMID:24191178

  5. Improving Solar Cells With Polycrystalline Silicon

    NASA Technical Reports Server (NTRS)

    Rohatgi, Ajeet; Campbell, Robert B.; Rai-Choudhury, Prosenjit

    1987-01-01

    In proposed solar-cell design, layers of polycrystalline silicon grown near front metal grid and back metal surface. Net electrical effect increases open-circuit voltage and short-circuit current, resulting in greater cell power output and energy conversion efficiency. Solar-cell configuration differs from existing one in that layers of doped polycrystalline silicon added to reduce recombination in emitter and back surface field regions.

  6. High performance porous silicon solar cell development

    Microsoft Academic Search

    S. M. Vernon; N. M. Kalkhoran; H. P. Maruska; W. D. Halverson

    1994-01-01

    We have fabricated Si solar cells from porous Si\\/bulk Si structures. Two cell types, having the junction within the porous Si or within the bulk Si, were studied. We have seen clear evidence of the photovoltaic effect in porous Si, although currents and voltages are low, due to spreading resistance problems. On a non-AR-coated bulk Si p-n junction solar cell,

  7. Single-nanowire Si solar cells

    Microsoft Academic Search

    M. D. Kelzenberg; D. B. Turner-Evans; B. M. Kayes; M. A. Filler; M. C. Putnam; N. S. Lewis; H. A. Atwater

    2008-01-01

    Solar cells based on arrays of CVD-grown Si nano- or micro-wires are being considered as a potentially low-cost route to implementing a vertical multijunction cell design via radial p-n junctions. This geometry has been predicted to enable efficiencies competitive with planar multicrystalline Si designs, while reducing the materials and processing costs of solar cell fabrication [1]. To further assess the

  8. Direct glassing of silicon solar cells

    NASA Astrophysics Data System (ADS)

    White, P. A.; Crabb, R. L.; Dollery, A. A.

    An alternate method of attaching coverglasses to silicon solar cells-currently achieved using silicone adhesives-is presented. The method is based on the electrostatic bonding of a specially developed glass that has an ideal expansion match to the silicon solar cell. Basically, the coverglass and cell are joined by a permanent chemical anodic bond formed by subjecting the cell and coverglass to voltage, temperature, and pressure while in intimate contact with each other. Because the front surface of the solar cell forms one of the bonding interfaces, it is important to understand the significance of changes in the cell design or type. Work performed in characterizing required cell parameters, e.g. coating type, texture, etc., and the effects of the bonding process on cell output are discussed.

  9. Dye-sensitized Solar Cells for Solar Energy Harvesting

    NASA Astrophysics Data System (ADS)

    Roy, M. S.; Deol, Y. S.; Kumar, Manish; Prasad, Narottam; Janu, Yojana

    2011-10-01

    Dye-sensitized solar cells (DSSCs) also known as Gratzel cells, have attracted the interests of researchers to a great extent because of its cost effective and easy manufacturing process without involving highly sophisticated lithographic technique and high cost raw materials as usually seen in conventional solar cell. Based on simple photo-electrochemical process, it has got immense potential in converting solar energy to electrical power in remote and desert area where the supply of conventional power is not possible. The overall peak power-production efficiency of dye-sensitized solar cells has been reported around 11 percent, so they are best suited to low-density applications and the price-to-performance ratio obtained through these solar cells is superior to others. DSSCs have ability to absorb even diffused sunlight and therefore work in cloudy whether as well without much impact over the efficiency. The present communication deals with a review of our work on DSSCs wherein we have used cost effective natural dyes/pigments as a sensitizer of nc-TiO2 and discussed about various key factors affecting the conversion efficiency of DSSC.

  10. Pharmacologic Alternatives to Riboflavin Photochemical Corneal Cross-Linking: A Comparison Study of Cell Toxicity Thresholds

    PubMed Central

    Kim, MiJung; Takaoka, Anna; Hoang, Quan V.; Trokel, Stephen L.; Paik, David C.

    2014-01-01

    Purpose. The efficacy of therapeutic cross-linking of the cornea using riboflavin photochemistry (commonly abbreviated as CXL) has caused its use to become widespread. Because there are known chemical agents that cross-link collagenous tissues, it may be possible to cross-link tissue pharmacologically. The present study was undertaken to compare the cell toxicity of such agents. Methods. Nine topical cross-linking agents (five nitroalcohols, glyceraldehyde [GLYC], genipin [GP], paraformaldehyde [FA], and glutaraldehyde [GLUT]) were tested with four different cell lines (immortalized human corneal epithelial cells, human skin fibroblasts, primary bovine corneal endothelial cells, and immortalized human retinal pigment epithelial cells [ARPE-19]). The cells were grown in planar culture and exposed to each agent in a range of concentrations (0.001 mM to 10 mM) for 24 hours followed by a 48-hour recovery phase. Toxicity thresholds were determined by using the trypan blue exclusion method. Results. A semiquantitative analysis using five categories of toxicity/fixation was carried out, based on plate attachment, uptake of trypan blue stain, and cellular fixation. The toxicity levels varied by a factor of 103 with the least toxic being mononitroalcohols and GLYC, intermediate toxicity for a nitrodiol and nitrotriol, and the most toxic being GLUT, FA, GP, and bronopol, a brominated nitrodiol. When comparing toxicity between different cell lines, the levels were generally in agreement. Conclusions. There are significant differences in cell toxicity among potential topical cross-linking compounds. The balance between cross-linking of tissue and cell toxicity should be borne in mind as compounds and strategies to improve mechanical tissue properties through therapeutic tissue cross-linking continue to develop. PMID:24722697

  11. Thermodynamic efficiency limit of excitonic solar cells

    SciTech Connect

    Giebink, Noel C. [Center for Nanoscale Materials, Argonne National Laboratory, Argonne, IL (United States); Wiederrecht, Gary P. [Center for Nanoscale Materials, Argonne National Laboratory, Argonne, IL (United States); Wasielewski, Michael R. [Northwestern Univ., Evanston, IL (United States); Forrest, Stephen R. [Univ. of Michigan, Ann Arbor, MI (United States)

    2011-05-01

    Excitonic solar cells, comprised of materials such as organic semiconductors, inorganic colloidal quantum dots, and carbon nanotubes, are fundamentally different than crystalline, inorganic solar cells in that photogeneration of free charge occurs through intermediate, bound exciton states. Here, we show that the Second Law of Thermodynamics limits the maximum efficiency of excitonic solar cells below the maximum of 31% established by Shockley and Queisser [J. Appl. Phys. 32, 510 (1961)] for inorganic solar cells (whose exciton-binding energy is small). In the case of ideal heterojunction excitonic cells, the free energy for charge transfer at the interface, ?G, places an additional constraint on the limiting efficiency due to a fundamental increase in the recombination rate, with typical ??G in the range 0.3 to 0.5 eV decreasing the maximum efficiency to 27% and 22%, respectively.

  12. Solar elastosis in conjunctival squamous cell neoplasm.

    PubMed

    Deka, A C; Dutta, A M; Sarma, P C; Baruah, K C

    2014-01-01

    Aim: To study the role of solar elastosis in the patient's with Conjunctival Squamous Cell Neoplasia (CSCN). Materials and Methods: Paraffin embedded 30 Conjunctival Squamous Cell Neoplasia tissues were studied for the presence of solar elastosis by Verhoeff's stain. Nineteen Squamous Cell Carcinoma (SCC), 6 Carcinoma In Situ (CIS) and 5 Conjunctival Intraepithelial Neoplasia (CIN) specimens were included in the study. Disease free conjunctiva and pterygium tissues were used as negative and positive control respectively. Results: Solar elastosis was found to be present in 19 of 30 (63.3%) Conjunctival Squamous Cell neoplasia specimens. Conclusion: Our study showed the presence of solar elastosis in conjunctival squamous cell neoplasia. Poor socioeconomic condition is an important factor as most of the elastosis positive patients were farmers. PMID:25494114

  13. Bypass diode for a solar cell

    DOEpatents

    Rim, Seung Bum; Kim, Taeseok; Smith, David D; Cousins, Peter J

    2013-11-12

    Methods of fabricating bypass diodes for solar cells are described. In once embodiment, a method includes forming a first conductive region of a first conductivity type above a substrate of a solar cell. A second conductive region of a second conductivity type is formed on the first conductive region. In another embodiment, a method includes forming a first conductive region of a first conductivity type above a substrate of a solar cell. A second conductive region of a second conductivity type is formed within, and surrounded by, an uppermost portion of the first conductive region but is not formed in a lowermost portion of the first conductive region.

  14. Heterojunction solar cell with passivated emitter surface

    DOEpatents

    Olson, Jerry M. (Lakewood, CO); Kurtz, Sarah R. (Golden, CO)

    1994-01-01

    A high-efficiency heterojunction solar cell wherein a thin emitter layer (preferably Ga.sub.0.52 In.sub.0.48 P) forms a heterojunction with a GaAs absorber layer. A passivating window layer of defined composition is disposed over the emitter layer. The conversion efficiency of the solar cell is at least 25.7%. The solar cell preferably includes a passivating layer between the substrate and the absorber layer. An anti-reflection coating is preferably disposed over the window layer.

  15. Catalysis of Photochemical Reactions.

    ERIC Educational Resources Information Center

    Albini, A.

    1986-01-01

    Offers a classification system of catalytic effects in photochemical reactions, contrasting characteristic properties of photochemical and thermal reactions. Discusses catalysis and sensitization, examples of catalyzed reactions of excepted states, complexing ground state substrates, and catalysis of primary photoproducts. (JM)

  16. Solar cell anomaly detection method and apparatus

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

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

  17. Indium oxide/n-silicon heterojunction solar cells

    DOEpatents

    Feng, Tom (Morris Plains, NJ); Ghosh, Amal K. (New Providence, NJ)

    1982-12-28

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

  18. PERSPECTIVE www.rsc.org/pps | Photochemical & Photobiological Sciences Effects of solar UV radiation on aquatic ecosystems and interactions with

    E-print Network

    Columbia University

    the general consensus that ozone-related increases in UV-B radiation can negatively influence many aquatic species and aquatic ecosystems (e.g., lakes, rivers, marshes, oceans). Solar UV radiation penetrates climate and UV radiation variability. There is also considerable evidence that aquatic species utilize

  19. The interdigitated back contact solar cell: A silicon solar cell for use in concentrated sunlight

    Microsoft Academic Search

    M. D. Lammert; R. J. Schwartz

    1977-01-01

    The theoretical and experimental performance of an interdigitated back contact solar cell is described. This type of cell is shown to have significant advantages over a conventional solar cell design when used at high concentration levels, namely, reduced internal series resistance, nonsaturating open-circuit voltage, and an absence of shadowing by front surface contacting fingers. The results of a computer study

  20. Photochemical Production and Behavior of Hydroperoxyacids in Heterotrophic Bacteria Attached to Senescent Phytoplanktonic Cells

    PubMed Central

    Petit, Morgan; Sempéré, Richard; Vaultier, Frédéric; Rontani, Jean-François

    2013-01-01

    The photooxidation of cellular monounsaturated fatty acids was investigated in senescent phytoplanktonic cells (Emiliania huxleyi) and in their attached bacteria under laboratory controlled conditions. Our results indicated that UV-visible irradiation of phytodetritus induced the photooxidation of oleic (produced by phytoplankton and bacteria) and cis-vaccenic (specifically produced by bacteria) acids. These experiments confirmed the involvement of a substantial singlet oxygen transfer from senescent phytoplanktonic cells to attached bacteria, and revealed a significant correlation between the concentration of chlorophyll, a photosensitizer, in the phytodetritus and the photodegradation state of bacteria. Hydroperoxyacids (fatty acid photoproducts) appeared to be quickly degraded to ketoacids and hydroxyacids in bacteria and in phytoplanktonic cells. This degradation involves homolytic cleavage (most likely induced by UV and/or transition metal ions) and peroxygenase activity (yielding epoxy acids). PMID:23736689

  1. 6, 78697904, 2006 Photochemical

    E-print Network

    Boyer, Edmond

    Chemistry and Physics Discussions Investigations of the photochemical isotope equilibrium between O2, CO2ACPD 6, 7869­7904, 2006 Photochemical isotope equilibrium between CO2 and O3 R. Shaheen et al­7904, 2006 Photochemical isotope equilibrium between CO2 and O3 R. Shaheen et al. Title Page Abstract

  2. Solar Cell Efficiency Tables (Version 33)

    Microsoft Academic Search

    Martin A. Green; Keith Emery; Yoshihiro Hishikawa; Wilhelm Warta

    2009-01-01

    Consolidated tables showing an extensive listing of the highest independently confirmed efficiencies for solar cells and modules are presented. Guidelines for inclusion of results into these tables are outlined and new entries since July 2008 are reviewed. Efficiencies are updated to the new reference solar spectrum tabulated in IEC 60904-3 Ed. 2 revised in April 2008 and an updated list

  3. Multi-junction solar cell designs

    Microsoft Academic Search

    Mahieddine Emziane; Adam Sleiman

    2011-01-01

    In this paper the designs of multi- junction solar cells for very high energy conversion efficiencies are reviewed. We highlight the importance of the concept of multi-junction solar devices and its superiority compared to other photovoltaic technologies. We present different types of multi-junction structures, and address the different electrical configurations used in various multi- junction designs.

  4. Germanium-on-glass solar cells

    Microsoft Academic Search

    Lorenzo Colace; Vito Sorianello; Carlo Maragliano; Gaetano Assanto; D. Fulgoni; L. Nash; M. Palmer

    2011-01-01

    We report on the fabrication and characterization of Ge solar cells on glass realized by layer transfer and epitaxial regrowth. These devices exhibit typical conversion efficiency exceeding 2.4% under AM1.5 irradiation and maximum efficiency of 3.7% under concentrated excitation. This approach enables flexible and affordable multi-junction engineering for solar energy conversion.

  5. Space solar cell research: Problems and potential

    Microsoft Academic Search

    D. J. Flood

    1986-01-01

    The value of a passive, maintenance-free, renewable energy source was apparent in the early days of the space program, and the silicon solar cell was pressed into service. Efficiencies of those early space solar arrays were low, and lifetimes shorter than hoped for, but within a decade significant advances had been made in both areas. Better performance was achieved through

  6. Space solar cell research - Problems and potential

    Microsoft Academic Search

    Dennis J. Flood

    1986-01-01

    The value of a passive, maintenance-free, renewable energy source was immediately recognized in the early days of the space program, and the silicon solar cell, despite its infancy, was quickly pressed into service. Efficiencies of those early space solar arrays were low, and lifetimes shorter than hoped for, but within a decade significant advances had been made in both areas.

  7. Radiation degradation of solar cell arrays

    NASA Technical Reports Server (NTRS)

    Hill, C. W.

    1975-01-01

    A method of incorporating a detailed solar cell radiation degradation model into a convenient computational scheme suitable for the solar electric propulsion system is outlined. The study shows that several existing codes may be applied in sequence to solve the problem.

  8. Transparent superstrate terrestrial solar cell module

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The design, development, fabrication, and testing of the transparent solar cell module were examined. Cell performance and material process characteristics were determined by extensive tests and design modifications were made prior to preproduction fabrication. These tests included three cell submodules and two full size engineering modules. Along with hardware and test activity, engineering documentation was prepared and submitted.

  9. Large area, low cost space solar cells

    NASA Technical Reports Server (NTRS)

    Kukulka, J.; Iles, P. A.

    1982-01-01

    This paper describes cost effective production-ready space solar cells which can meet the requirements for use on the Space Shuttle and other large space missions. Actual yield and performance data for these cells, as well as cost comparisons between these and standard space cells are included.

  10. High-efficiency thin silicon solar cells

    Microsoft Academic Search

    J. Michel; E. Fabre; M. Mautref

    1976-01-01

    Computer analysis of 'black' silicon solar cells with a n(plus)\\/p\\/p(plus) structure have been made. Detailed results are shown as a function of doping level, minority carrier diffusion length in bulk material and cell thickness. Experimental results show that good conversion efficiencies can be achieved with thin cells (100 microns) without any antireflective coating.

  11. Large area, low cost space solar cells

    SciTech Connect

    Kukulka, J.; Iles, P.A.

    1982-09-01

    This paper describes cost effective production-ready space solar cells which can meet the requirements for use on the space shuttle and other large space missions. Actual yield and performance data for these cells, as well as cost comparisons between these and standard space cells are included.

  12. Mars optimized solar cell technology (MOST)

    Microsoft Academic Search

    Paul M. Stella; Nick Mardesich; Kenneth Edmondson; Chris Fetzer; Andreea Boca

    2008-01-01

    Solar cells used for all Mars surface applications have been commercially available space qualified AM0 devices optimized for Earth orbiting geosynchronous applications. Due to fine dust circulating in the Martian atmosphere, which reduces the short wavelength light component, these cells are not optimized for Mars surface operation. As a result, these cells operate at less than optimal efficiency. As part

  13. Solar Cells With Multiple Small Junctions

    NASA Technical Reports Server (NTRS)

    Daud, T.; Koliwad, K. M.

    1985-01-01

    Concept for improving efficiency of photovoltaic solar cells based on decreasing p/n junction area in relation to total surface area of cell. Because of reduced junction area, surface leakage drops and saturation current density decreases. Surface passivation helps to ensure short-circuit current remains at high value and response of cells to blue light increases.

  14. Solar cell anomaly detection method and apparatus

    Microsoft Academic Search

    M. K. Gauthier; E. L. Miller; A. Shumka

    1981-01-01

    A method is provided for detecting cracks and other imperfections in a solar cell, which includes scanning a narrow light beam back and forth across the cell in a raster pattern, while monitoring the electrical output of the cell to find locations where the electrical output varies significantly. The electrical output can be monitored on a television type screen containing

  15. COLLOIDAL SEMICONDUCTOR NANOCRYSTALS BASED SOLAR CELLS

    E-print Network

    Tessler, Nir

    .; Tessler, N., Hybrid Organic-nanocrystal Photovoltaic Cells with Enhanced near IR response. In European nanoimprinting - Application to organic solar cells optimization. Organic Electronics 2011, 12 (7), 1241-1246. 5, O.; Banin, U.; Tessler, N., Novel all-Nanocrystals bulk heterojunction photovoltaic cells through

  16. Ultrathin silicon solar cell for space application

    Microsoft Academic Search

    T. Matsutani; T. Saga; H. Ueyama; Y. Hagihara; T. Hirano; A. Suzuki

    1982-01-01

    Ultrathin silicon (Si) solar cells for space application were fabricated on an experimental basis and the electrical characteristics were investigated for three kinds of cells (Black, BSFR and Conventional cells). Under 135.3 mW sq cm (AM0) illumination, ultrathin Black cells showed 67.7 mW output, which is equal to 89 percent output of 280 micron Black cells. The power to mass

  17. Wide band gap Gallium Phosphide solar cells for multi-junction solar cell system

    Microsoft Academic Search

    Xuesong Lu; S. R. Huang; M. Diaz; R. L. Opila; A. Barnett

    2010-01-01

    Gallium Phosphide (GaP) solar cells have been designed, fabricated, characterized and analyzed as candidates for the top junction solar cell in a multi-junction solar cell system. Liquid phase epitaxy (LPE) has been used as the growth method for the epitaxial layers. Open circuit voltage (Voc) of 1.535V has been achieved under one sun illumination from the outdoor test. Quantum efficiency

  18. Microstructured surface design for omnidirectional antireflection coatings on solar cells

    E-print Network

    Zhou, Weidong

    .g., silicon nitride SiNx thin film for silicon Si solar cells, is often used as a cost effective approachMicrostructured surface design for omnidirectional antireflection coatings on solar cells Weidong to current crystalline silicon solar cells, as well as future thin film, quantum dot, and organic solar cells

  19. Calculating the generation function of III-V solar cells

    Microsoft Academic Search

    G. Letay; M. Breselge; A. W. Bett

    2003-01-01

    Modelling the electrical response of a III-V solar cell requires an exact knowledge of the distribution of photogenerated electron hole pairs G(z) within the solar cell structure. Also, this generation function, connects the optical with the electrical part of a solar cell model. In contrast to silicon solar cells, 99 % of the light is absorbed in the first few

  20. Space solar cells: High efficiency and radiation damage

    NASA Technical Reports Server (NTRS)

    Brandhorst, H., Jr.; Bernatowicz, D. T.

    1980-01-01

    The progress and status of efforts to increase the end-of-life efficiency of solar cells for space use is assessed. High efficiency silicon solar cells, silicon solar cell radiation damage, GaAs solar cell performance and radiation damage and 30 percent devices are discussed.

  1. III-V material solar cells for space application

    Microsoft Academic Search

    T. V. Torchynska; G. P. Polupan

    2002-01-01

    The present paper is a review of current situation in space solar cell engineering. The comparison of the Si and III-V solar cell performances, as well as their parameter variation with temperature rise, radiation treatments and improving design were analyzed. The modern directions of the space solar cell development and international space projects, applied new types of solar cells, were

  2. Colloidal cluster phases and solar cells 

    E-print Network

    Mailer, Alastair George

    2012-11-28

    The arrangement of soft materials through solution processing techniques is a topic of profound importance for next generation solar cells; the resulting morphology has a major influence on construction, performance and ...

  3. EE580 Solar Cells Todd J. Kaiser

    E-print Network

    Kaiser, Todd J.

    as incorrect Monocrystalline silicon energy payback is 7 3­ Monocrystalline silicon energy payback is 7.3 years Photovoltaic Myth #7 · PV involves toxic materials ­ Minimal toxic materials in silicon solar cells, but used

  4. Heavily doped polysilicon-contact solar cells

    NASA Technical Reports Server (NTRS)

    Lindholm, F. A.; Neugroschel, A.; Arienzo, M.; Iles, P. A.

    1985-01-01

    The first use of a (silicon)/heavily doped polysilicon)/(metal) structure to replace the conventional high-low junction or back-surface-field (BSF) structure of silicon solar cells is reported. Compared with BSF and back-ohmic-contact (BOC) control samples, the polysilicon-back solar cells show improvements in red spectral response (RSR) and open-circuit voltage. Measurement reveals that a decrease in effective surface recombination velocity S is responsible for this improvement. Decreased S results for n-type (Si:As) polysilicon, consistent with past findings for bipolar transistors, and for p-type (Si:B) polysilicon, reported here for the first time. Though the present polysilicon-back solar cells are far from optimal, the results suggest a new class of designs for high efficiency silicon solar cells. Detailed technical reasons are advanced to support this view.

  5. Inexpensive silicon sheets for solar cells

    NASA Technical Reports Server (NTRS)

    Ciszek, T. F.; Schwuttke, G. H.

    1977-01-01

    Technique of producing silicon sheets by drawing gridlike or porous graphite gauze through silicon melt is readily adaptable to mass production, making process applicable to inexpensive manufacture of solar cell arrays.

  6. Selective laser patterning in organic solar cells

    NASA Astrophysics Data System (ADS)

    Abreu Fernandes, S.; Maragkaki, S.; Ostendorf, A.

    2014-10-01

    Selective laser patterning for integrative serious connection has been industrially established in inorganic thin film solar cells based on glass substrates since a few years. In organic solar cells (OSC) the used materials significantly differ in terms of their patterning behavior. Due to their processability by wet chemical methods inverted architectures are often preferred in organic solar cells which allow the patterning by ultrashort laser pulses in substrate and superstrate configuration. Starting with an introduction of the ablation mechanisms taking place in OSC thin films, an overview of the current state-of-the-art in laser patterning of organic solar cells is presented. Besides progress in research also current achievements in industrial applications are illustrated.

  7. Texturization of multicrystalline silicon solar cells

    E-print Network

    Li, Dai-Yin

    2010-01-01

    A significant efficiency gain for crystalline silicon solar cells can be achieved by surface texturization. This research was directed at developing a low-cost, high-throughput and reliable texturing method that can create ...

  8. Solar cell array design handbook. Volume II

    Microsoft Academic Search

    Rauschenbach

    1976-01-01

    This volume contains detailed design data in an appendix-like fashion and includes solar cell performance data, applicable unit conversion factors and physical constants, and mechanical, electrical, thermal, optical, magnetic, and outgassing material properties. Extensive references are provided.

  9. Solar cell array design handbook, volume 1

    NASA Technical Reports Server (NTRS)

    Rauschenbach, H. S.

    1976-01-01

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

  10. Dye-sensitized solar cells

    DOEpatents

    Skotheim, Terje A. [Berkeley, CA

    1980-03-04

    A low-cost dye-sensitized Schottky barrier solar cell comprised of a substrate of semiconductor with an ohmic contact on one face, a sensitizing dye adsorbed onto the opposite face of the semiconductor, a transparent thin-film layer of a reducing agent over the dye, and a thin-film layer of metal over the reducing agent. The ohmic contact and metal layer constitute electrodes for connection to an external circuit and one or the other or both are made transparent to permit light to penetrate to the dye and be absorbed therein for generating electric current. The semiconductor material chosen to be the substrate is one having a wide bandgap and which therefore is transparent; the dye selected is one having a ground state within the bandgap of the semiconductor to generate carriers in the semiconductor, and a first excited state above the conduction band edge of the semiconductor to readily conduct electrons from the dye to the semiconductor; the reducing agent selected is one having a ground state above the ground state of the sensitizer to provide a plentiful source of electrons to the dye during current generation and thereby enhance the generation; and the metal for the thin-film layer of metal is selected to have a Fermi level in the vicinity of or above the ground state of the reducing agent to thereby amply supply electrons to the reducing agent.

  11. Dye-sensitized solar cells

    DOEpatents

    Skotheim, T.A.

    1980-03-04

    A low-cost dye-sensitized Schottky barrier solar cell is comprised of a substrate of semiconductor with an ohmic contact on one face, a sensitizing dye adsorbed onto the opposite face of the semiconductor, a transparent thin-film layer of a reducing agent over the dye, and a thin-film layer of metal over the reducing agent. The ohmic contact and metal layer constitute electrodes for connection to an external circuit and one or the other or both are made transparent to permit light to penetrate to the dye and be absorbed therein for generating electric current. The semiconductor material chosen to be the substrate is one having a wide bandgap and which therefore is transparent; the dye selected is one having a ground state within the bandgap of the semiconductor to generate carriers in the semiconductor, and a first excited state above the conduction band edge of the semiconductor to readily conduct electrons from the dye to the semiconductor; the reducing agent selected is one having a ground state above the ground state of the sensitizer to provide a plentiful source of electrons to the dye during current generation and thereby enhance the generation; and the metal for the thin-film layer of metal is selected to have a Fermi level in the vicinity of or above the ground state of the reducing agent to thereby amply supply electrons to the reducing agent. 3 figs.

  12. T cell and B Cell immunity can be reconstituted with mismatched hematopoietic stem cell transplantation without alkylator therapy in artemis-deficient mice using anti-natural killer cell antibody and photochemically treated sensitized donor T cells.

    PubMed

    Xiao, Tony Z; Singh, Kanal; Dunn, Elizabeth; Ramachandran, Rageshree; Cowan, Morton J

    2012-02-01

    Children with Artemis-deficient T(-)B(-)NK(+) severe combined immunodeficiency are at high risk for graft rejection from natural killer (NK) cells and toxicity from increased sensitivity to the alkylating agents used in mismatched hematopoietic stem cell transplantation (HSCT). We evaluated the use of a nonalkylating agent regimen before HSCT in Artemis-deficient (mArt(-/-)) C57Bl/6 (B6) mice to open marrow niches and achieve long-term multilineage engraftment with full T cell and B cell immune reconstitution. We found that partial depletion of both recipient NK cells using anti-NK1.1 monoclonal antibody and donor T cells sensitized to recipient splenocytes was necessary. BALB/c-sensitized T cells (STCs) were photochemically treated (PCT) with psoralen and UVA light to inhibit proliferation, reduce the risk of graft-versus-host disease (GVHD), and target host hematopoietic stem cells (HSCs). A dose of 4 × 10(5) PCT STCs coinjected with 1 × 10(5) lineage-depleted c-kit(+) BALB/c HSCs resulted in 43.9% ± 3.3% CD4(+) and 10.9% ± 1.2% CD8(+) donor T cells in blood, 29% ± 7.8% and 21.7% ± 4.0 donor B220(+) IgM(+) in spleen and bone marrow, and 15.0% ± 3.6% donor Gran-1(+) cells in bone marrow at 6 months post-HSCT versus 0.02% ± 0.01%, 0.13% ± 0.10%, 0.53% ± 0.16%, 0.49% ± 0.09%, and 0.20% ± 0.06%, respectively, in controls who did not receive PCT STCs. We found that STCs target host HSCs and that PCT STCs are detectable only up to 24 hours after infusion, in contrast to non-photochemically treated STCs, which proliferate resulting in fatal GVHD. Increased mortality in the groups receiving 4-6 × 10(5) PCT STCs was associated with evidence of GVHD, particularly in the recipients of 6 × 10(5) cells. These results demonstrate that blocking NK cell-mediated resistance and making niches in bone marrow are both essential to achieving multilineage engraftment of mismatched donor cells and T cell and B cell reconstitution, even though GVHD is not completely eliminated. PMID:22015994

  13. A space solar cell bonding robot

    Microsoft Academic Search

    Zhuang Fu; Yan-zheng Zhao; Ren-qiang Liu; Zhi Dong

    2006-01-01

    A space solar cell bonding robot system which consists of a three-axis Cartesian coordinate’s robot, coating device, bonding\\u000a device, orientation plate, and control subsystem was studied. A method, which can control the thickness of adhesive layer\\u000a on the solar cell, was put forward and the mechanism was designed. Another method which can achieve the auto-bonding between\\u000a thin cover-glass and the

  14. Limiting efficiency of silicon solar cells

    Microsoft Academic Search

    TOM TIEDJE; ELI YABLONOVITCH; GEORGE D. CODY; BONNIE G. BROOKS

    1984-01-01

    The detailed balance method for calculating the radiative recombination limit to the performance of solar cells has been extended to include free carrier absorption and Auger recombination in addition to radiative losses. This method has been applied to crystalline silicon solar cells where the limiting efficiency is found to be 29.8 percent under AM1.5, based on the measured optical absorption

  15. Characterization of cadmium zinc telluride solar cells

    Microsoft Academic Search

    Gowri Sivaraman

    2003-01-01

    Currently thin film solar cells have efficiencies in the range of 16-18%. Higher efficiencies of 20% or more can be achieved by two junction solar cells in which two p-n junctions are connected in series one on top of the other in a tandem structure. The ideal bandgaps for optimum efficiency in a tandem structure are about 1eV for the

  16. Silicon solar cells, a manufacturing cost analysis

    NASA Technical Reports Server (NTRS)

    Grenon, L. A.; Coleman, M. G.

    1978-01-01

    A detailed cost analysis of solar cell module manufacturing, utilizing process sequences incorporating near-term technology, has been performed. The entire structuring of a factory to manufacture solar cell modules, starting from supplied polycrystalline silicon and other raw materials, was specified. This analysis then formed the basis for a sensitivity analysis of the major cost factors. The results of the cost and sensitivity analyses are presented here.

  17. Dye sensitized solar cells on paper substrates

    Microsoft Academic Search

    Bo Wang; Lei L. Kerr

    2011-01-01

    This article reports for the first time in the literature, a dye sensitized solar cells with 1.21% efficiency (Voc=0.56V, Jsc=6.70mA\\/cm2 and F.F.=0.33) on paper substrates. The current dye sensitized solar cell technology is based on fluorine doped SnO2 (FTO) coated glass substrates. The problem with the glass substrate is its rigidity and heavy weight. Making DSSCs on paper opens the

  18. Amorphous thin-film solar cells

    Microsoft Academic Search

    W. Krühler

    1991-01-01

    This report gives an overview of the present status of thin-film solar cells made from hydrogenated amorphous semiconductors (a-Si:H, a-Ge:H) together with new results emphasizing the physics of amorphous materials and devices. Preparation techniques, quality and performances of a-Si:H and a-Ge:H films as well as solar cells with pin structures are reviewed. Dark and light current-voltage I(V) characteristics and spectral

  19. Schottky solar cells on thin epitaxial silicon

    Microsoft Academic Search

    W. A. Anderson; S. M. Vernon; P. Mathe; B. Lalevic

    1976-01-01

    Schottky solar cells fabricated on 10, 20 and 30 micron epitaxial silicon produce a current density ranging from about 10-22 mA\\/sq cm, depending on Si thickness and orientation, in close agreement with theoretically predicted data. These results are also in close agreement with recent data on p-n solar cells, using thin epitaxial silicon. Data reported herein predict that 10% efficient

  20. Nanowire dye-sensitized solar cells

    Microsoft Academic Search

    Matt Law; Lori E. Greene; Justin C. Johnson; Richard Saykally; Peidong Yang

    2005-01-01

    Excitonic solar cells-including organic, hybrid organic-inorganic and dye-sensitized cells (DSCs)-are promising devices for inexpensive, large-scale solar energy conversion. The DSC is currently the most efficient and stable excitonic photocell. Central to this device is a thick nanoparticle film that provides a large surface area for the adsorption of light-harvesting molecules. However, nanoparticle DSCs rely on trap-limited diffusion for electron transport,

  1. Magnetoresistance in bulk heterojunction solar cells

    Microsoft Academic Search

    Ronald Oesterbacka; Sayani Majumdar; Himadri Majumdar; Harri Aarnio; Reino Laiho

    2008-01-01

    The magnetoresistance (MR) response of the poly(3-hexyl thiophene) and poly(3-hexyl thiophene):1-(3-methoxycarbonyl) propyl-1-phenyl-[6,6]-methanofullerene (PHT:PCBM) based bulk heterojunction solar cells have been studied. Positive MR was always observed at room temperature in both the devices. In both cases the magnitude of the MR signal decreases at lower temperature and shows positive to negative sign inversion at 100K for the solar cells and

  2. High-temperature Solar Cell Development

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

    The vast majority of space probes to date have relied upon photovoltaic power generation. If future missions designed to probe environments close to the sun (Figure 1) will be able to use such power generation, solar cells that can function at high temperatures, under high light intensity, and high radiation conditions must be developed. The significant problem is that solar cells lose performance at high temperatures.

  3. Microstructural analysis of solar cell welds

    Microsoft Academic Search

    T. J. Moore; G. K. Watson; C. R. Baraona

    1982-01-01

    Parallel-gap resistance welding of silicon solar cells with copper interconnects results in complex microstructural variations that depend on the welding variables. At relatively low heat input solid-state welds are produced. At medium heat the Ag-Cu eutectic forms resulting in a braze joint. High heat produces a fusion weld with complete melting of the silver layer on the silicon solar cell.

  4. Probing Dynamic Cell-Substrate Interactions using Photochemically Generated Surface-Immobilized Gradients: Application to Selectin-Mediated Leukocyte Rolling

    PubMed Central

    Herman, Christine T.; Potts, Gregory K.; Michael, Madeline C.; Tolan, Nicole V.

    2014-01-01

    Model substrates presenting biochemical cues immobilized in a controlled and well-defined manner are of great interest for their applications in biointerface studies that elucidate the molecular basis of cell receptor-ligand interactions. Herein, we describe a direct, photochemical method to generate one-component surface-immobilized biomolecular gradients that are applied to the study of selectin-mediated leukocyte rolling. The technique employs benzophenone-modified glass substrates, which upon controlled exposure to UV light (350 – 365 nm) in the presence of protein-containing solutions facilitate the generation of covalently immobilized protein gradients. Conditions were optimized to generate gradient substrates presenting P-selectin and PSGL-1 (P-selectin Glycoprotein Ligand-1) immobilized at site densities over a 5- to 10-fold range (from as low as ~200 molecules/?m2 to as high as 6000 molecules/?m2). The resulting substrates were quantitatively characterized via fluorescence analysis and radioimmunoassays before their use in the leukocyte rolling assays. HL-60 promyelocytes and Jurkat T lymphocytes were assessed for their ability to tether to and roll on substrates presenting immobilized P-selectin and PSGL-1 under conditions of physiologically relevant shear stress. The results of these flow assays reveal the combined effect of immobilized protein site density and applied wall shear stress on cell rolling behavior. Two-component substrates presenting P-selectin and ICAM-1 (intercellular adhesion molecule-1) were also generated to assess the interplay between these two proteins and their effect on cell rolling and adhesion. These proof-of-principle studies verify that the described gradient generation approach yields well-defined gradient substrates that present immobilized proteins over a large range of site densities that are applicable for investigation of cell-materials interactions, including multi-parameter leukocyte flow studies. Future applications of this enabling methodology may lead to new insights into the biophysical phenomena and molecular mechanism underlying complex biological processes such as leukocyte recruitment and the inflammatory response. PMID:21614364

  5. Interdigitated back contact solar cells. Annual report

    SciTech Connect

    Lundstrom, M.S.; Schwartz, R.J.

    1980-08-01

    The interdigitated back-contact solar cell (IBC cell) has been shown to possess a number of advantages for silicon solar cells, which operate at high concentration. The purpose of the present program is to support the Sandia Laboratory effort to optimize the IBC cell. A detailed discussion of the factors which need to be considered in the analysis of semiconducting devices which utilize heavily doped regions such as those which are found in solar cells in both the emitter and in the back surface field regions is given. This discussion covers the questions of: how to handle degeneracy, how to compute carrier concentrations in the absence of knowledge of the details of the band structure under heavily doped conditions, how to reconcile the usual interpretation of heavy doping as a rigid shift of the bands with the band tailing and impurity level conduction models. It also discusses the reasons for the observed discrepancy between various experimental measurements of bandgap narrowing. A discussion of the appropriateness of using experimentally determined parameters in conjunction with degenerate statistics in calculating cell performance is also presented. A detailed discussion of the one dimensional formulation of the solar cell analysis as well as a description of the one dimensional programs which have been writtten to perform this analysis are included. The results of calculations using the one dimensional program to analyze typical situations which occur in high intensity conventionally designed silicon solar cells are presented.

  6. High conversion efficiency photoelectrochemical solar cells

    NASA Astrophysics Data System (ADS)

    Pandey, R. N.; Babu, K. S. Chandra; Srivastava, O. N.

    1996-07-01

    The present review focusses on the prospectives and perspectives of high conversion efficiency photoelectrochemical (PEC) solar cells. The PEC solar cells score over their solid state counterparts on several points. Some of these axe ease of fabrication and inbuilt storage capability. In order to make PEC solar cells viable, their conversion efficiencies need to be enhanced so as to reach optimum values. Several feasible efficiency enhancement processes for PEC cells such as electrode surface modification, photoetching, electrolyte modification etc. have been described and discussed in this article. The case of efficiency enhancement of n-GaAs based PEC solar cell through the modification of GaAs by Os 3+ or Ru 3+ ions leading to efficiency enhancement from 9 to 15% has been described and discussed. In regard to efficiency enhancement through electrolyte modification, the example of n-CdSe based PEC cell where the electrolyte ( {K3Fe(CN)6}/{K4Fe(CN)6}) is modified through KCN has been dealt with. The efficiency obtained in this cell is upto 16%. For the PEC solar cells embodying the d-d phototransition, MX 2 type layered materials, the most dramatic conversion efficiency enhancements come through photoetching of electrode surfaces. We have described and discussed in detail the efficiency enhancements in {n-WSe 2}/{I 3-}, {I -}/{Pt} solar cells through photoetching of n-WSe 2 photoelectrodes in 0.1 M aquaregia. High efficiencies upto 17% have been obtained for those solar cells. Yet another route of fabricating viable PEC solar cells giving high power output corresponds to the development of newer PEC cell designs. One example of the newer cell designs which has been described and discussed in this article corresponds to semiconductor-septum (SC-SEP) PEC solar cell. The SC-SEP, PEC solar cells have been found to yield higher power outputs (V oc and I sc) than the conventional single compartment PEC cells. For example, {n-CdSe}/{Ti} septum based PEC solar cell with configuration - Pt, 1 M-3S// n-CdSe/ Ti//0.1M AgN0 3, Pt has been found to give higher power output (1.42 V and 20 mA/cm 2), as compared to n-CdSe based conventional PEC cell (0.64 V and 6 mA/cm 2). Similarly, {n-TiO 2}/{Ti} septum electrode based SC-SEP, cell - Pt, l M NaOH/ n-TiO 2/Ti/0.1M AgNO 3, Pt also gives higher power output (1.2 V and 15 mA/cm 2). The case of another new PEC cell design incorporating nanostructured TiO 2 photoelectrode overlaid with special dye (Ruthenium trinuclear cyanide complex) and exhibiting efficiencies of 7% (under usual solar illumination) and 12% (in diffuse solar light) has also been outlined.

  7. Optimization and performance of Space Station Freedom solar cells

    NASA Technical Reports Server (NTRS)

    Khemthong, S.; Hansen, N.; Bower, M.

    1991-01-01

    High efficiency, large area and low cost solar cells are the drivers for Space Station solar array designs. The manufacturing throughput, process complexity, yield of the cells, and array manufacturing technique determine the economics of the solar array design. The cell efficiency optimization of large area (8 x 8 m), dielectric wrapthrough contact solar cells are described. The results of the optimization are reported and the solar cell performance of limited production runs is reported.

  8. Back-contact vertical-junction solar cell. Master's thesis

    Microsoft Academic Search

    1988-01-01

    The objective of this thesis was to improve the efficiency of silicon solar cells by designing and fabricating a solar cell which synergistically combines the advantages of the interdigitated back-contact solar cell with the advantages of the wedged-channel vertical-junction solar cell. Solar cell designs which combine the two concepts were proposed and evaluated. A final design was chosen which consisted

  9. Advanced solar cells for satellite power systems

    NASA Astrophysics Data System (ADS)

    Flood, Dennis J.; Weinberg, Irving

    1994-11-01

    The multiple natures of today's space missions with regard to operational lifetime, orbital environment, cost and size of spacecraft, to name just a few, present such a broad range of performance requirements to be met by the solar array that no single design can suffice to meet them all. The result is a demand for development of specialized solar cell types that help to optimize overall satellite performance within a specified cost range for any given space mission. Historically, space solar array performance has been optimized for a given mission by tailoring the features of silicon solar cells to account for the orbital environment and average operating conditions expected during the mission. It has become necessary to turn to entirely new photovoltaic materials and device designs to meet the requirements of future missions, both in the near and far term. This paper will outline some of the mission drivers and resulting performance requirements that must be met by advanced solar cells, and provide an overview of some of the advanced cell technologies under development to meet them. The discussion will include high efficiency, radiation hard single junction cells; monolithic and mechanically stacked multiple bandgap cells; and thin film cells.

  10. Manufacture of Solar Cells on the Moon

    NASA Technical Reports Server (NTRS)

    Freundich, Alex; Ignatiev, Alex; Horton, Charles; Duke, Mike; Curren, Peter; Sibille, Laurent

    2005-01-01

    In support of the space exploration initiative a new architecture for the production of solar cells on the lunar surface is devised. The paper discusses experimental data on the fabrication and properties of lunar glass substrates, evaporated lunar regolith thin film (antireflect coatings and insulators), and preliminary attempts in the fabrication of thin film (silicon/II-VI) photovoltaic materials on lunar regolith substrates. A conceptual design for a solar powered robotic rover capable of fabricating solar cells directly on the lunar surface is provided. Technical challenges in the development of such a facility and strategies to alleviate perceived difficulties are discussed. Finally, preliminary cost benefit ratio analysis for different in situ solar cell production scenarios (using exclusively in-situ planetary resources or hybrid) are discussed.

  11. Mechanically-stacked multijunction solar cells

    SciTech Connect

    Gee, J.M.

    1985-01-01

    The results of experiments to simulate the performance of mechanically-stacked, multijunction solar cells are reported. The simulation consisted of stacking an AlGaAs optical filter on top of a silicon cell and measuring the silicon cell's output. Analysis of the experimental results was able to quantify the various mechanisms (absorption and reflection) that resulted in the loss of silicon cell output. Calculations were also performed to compare the relative merits of two different types of silicon cells and an InGaAs cell for stacked cell applications.

  12. Plastic Schottky-barrier solar cells

    DOEpatents

    Waldrop, J.R.; Cohen, M.J.

    1981-12-30

    A photovoltaic cell structure is fabricated from an active medium including an undoped polyacetylene, organic semiconductor. When a film of such material is in rectifying contact with a metallic area electrode, a Schottky-barrier junction is obtained within the body of the cell structure. Also, a gold overlayer passivates a magnesium layer on the undoped polyacetylene film. With the proper selection and location of elements a photovoltaic cell structure and solar cell are obtained.

  13. Modeling of polycrystalline thin film solar cells

    Microsoft Academic Search

    Alan L. Fahrenbruch

    1999-01-01

    This paper describes modeling polycrystalline thin-film solar cells using the program AMPS-1D1 to visualize the relationships between the many variables involved. These simulations are steps toward two dimensional modeling the effects of grain boundaries in polycrystalline cells. Although this paper describes results for the CdS\\/CdTe cell, the ideas presented here are applicable to copper-indium-gallium selenide (CIGS) cells as well as

  14. Emitter Wrap-Through solar cell

    SciTech Connect

    Gee, J.M.; Schubert, W.K.; Basore, P.A.

    1992-01-01

    The authors present a new cell concept (Emitter Wrap-Through or EWT) for a back-contact cell. The cell has laser-drilled vias to wrap the emitter on the front surface to contacts on the back surface and uses a potentially low-cost process sequence. Modeling calculations show that efficiencies of 18 and 21% are possible with large-area solar-grade multi- and monocrystalline silicon EWT cells, respectively.

  15. Progress in quantum well solar cells

    Microsoft Academic Search

    M. Mazzer; K. W. J. Barnham; I. M. Ballard; A. Bessiere; A. Ioannides; D. C. Johnson; M. C. Lynch; T. N. D. Tibbits; J. S. Roberts; G. Hill; C. Calder

    2006-01-01

    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

  16. 18 percent efficient polycrystalline silicon solar cells

    Microsoft Academic Search

    S. Narayanan; J. Zolper; F. Yun; S. R. Wenham; A. B. Sproul

    1990-01-01

    Over the past 7 yr, there has been marked improvements in crystalline silicon solar cell performance, with the highest independently confirmed cell efficiency increasing from 17.1 percent to 24.2 percent. Work directed at transferring some of these improvements to polycrystalline silicon cells is described. Applying a high-efficiency crystalline cell sequence has given efficiencies as high as 17.8 percent with the

  17. Nanoscale Charge Transport in Excitonic Solar Cells

    SciTech Connect

    Venkat Bommisetty, South Dakota State University

    2011-06-23

    Excitonic solar cells, including all-organic, hybrid organic-inorganic and dye-sensitized solar cells (DSSCs), offer strong potential for inexpensive and large-area solar energy conversion. Unlike traditional inorganic semiconductor solar cells, where all the charge generation and collection processes are well understood, these excitonic solar cells contain extremely disordered structures with complex interfaces which results in large variations in nanoscale electronic properties and has a strong influence on carrier generation, transport, dissociation and collection. Detailed understanding of these processes is important for fabrication of highly efficient solar cells. Efforts to improve efficiency are underway at a large number of research groups throughout the world focused on inorganic and organic semiconductors, photonics, photophysics, charge transport, nanoscience, ultrafast spectroscopy, photonics, semiconductor processing, device physics, device structures, interface structure etc. Rapid progress in this multidisciplinary area requires strong synergetic efforts among researchers from diverse backgrounds. Such effort can lead to novel methods for development of new materials with improved photon harvesting and interfacial treatments for improved carrier transport, process optimization to yield ordered nanoscale morphologies with well defined electronic structures.

  18. Stable, high-efficiency amorphous silicon solar cells with low hydrogen content. Annual subcontract report, 1 March 1991--31 January 1992

    SciTech Connect

    Fortmann, C.M.; Hegedus, S.S. [Institute of Energy Conversion, Newark, DE (United States)

    1992-12-01

    Results and conclusions obtained during a research program of the investigation of amorphous silicon and amorphous silicon based alloy materials and solar cells fabricated by photo-chemical vapor and glow discharge depositions are reported. Investigation of the effects of the hydrogen content in a-si:H i-layers in amorphous silicon solar cells show that cells with lowered hydrogen content i-layers are more stable. A classical thermodynamic formulation of the Staebler-Wronski effect has been developed for standard solar cell operating temperatures and illuminations. Methods have been developed to extract a lumped equivalent circuit from the current voltage characteristic of a single junction solar cell in order to predict its behavior in a multijunction device.

  19. Nanoparticle Solar Cell Final Technical Report

    SciTech Connect

    Breeze, Alison, J; Sahoo, Yudhisthira; Reddy, Damoder; Sholin, Veronica; Carter, Sue

    2008-06-17

    The purpose of this work was to demonstrate all-inorganic nanoparticle-based solar cells with photovoltaic performance extending into the near-IR region of the solar spectrum as a pathway towards improving power conversion efficiencies. The field of all-inorganic nanoparticle-based solar cells is very new, with only one literature publication in the prior to our project. Very little is understood regarding how these devices function. Inorganic solar cells with IR performance have previously been fabricated using traditional methods such as physical vapor deposition and sputtering, and solution-processed devices utilizing IR-absorbing organic polymers have been investigated. The solution-based deposition of nanoparticles offers the potential of a low-cost manufacturing process combined with the ability to tune the chemical synthesis and material properties to control the device properties. This work, in collaboration with the Sue Carter research group at the University of California, Santa Cruz, has greatly expanded the knowledge base in this field, exploring multiple material systems and several key areas of device physics including temperature, bandgap and electrode device behavior dependence, material morphological behavior, and the role of buffer layers. One publication has been accepted to Solar Energy Materials and Solar Cells pending minor revision and another two papers are being written now. While device performance in the near-IR did not reach the level anticipated at the beginning of this grant, we did observe one of the highest near-IR efficiencies for a nanoparticle-based solar cell device to date. We also identified several key parameters of importance for improving both near-IR performance and nanoparticle solar cells in general, and demonstrated multiple pathways which showed promise for future commercialization with further research.

  20. Excess currents in MINP-type solar cells

    Microsoft Academic Search

    B. B. Rao; S. Banerjee; W. A. Anderson; M. K. Han

    1985-01-01

    Green et al. (1982) have reported the introduction of the MINP solar cell. This cell has a high open-circuit voltage and utilizes an insulator layer over the shallow n(+) region. The present investigation is concerned with the conduction mechanisms and the role of excess dark current in high-efficiency solar cells. Three cells were fabricated, including a MINP solar cell, a

  1. Radiation hardened high efficiency silicon space solar cell

    Microsoft Academic Search

    V. Garboushian; S. Yoon; J. Turner

    1993-01-01

    A silicon solar cell with AMO 19% Beginning of Life (BOL) efficiency is reported. The cell has demonstrated equal or better radiation resistance when compared to conventional silicon space solar cells. Conventional silicon space solar cell performance is generally ≈14% at BOL. The Radiation Hardened High Efficiency Silicon (RHHES) cell is thinned for high specific power (watts\\/kilogram). The RHHES space

  2. Method of manufacturing an array of solar cells

    Microsoft Academic Search

    1983-01-01

    An arrangement or array of solar cells comprises a plurality of cells each having contacting connectors which establish an electrically conducting connection between the individual solar cells. Each solar cell has a connector which projects slightly from the edge thereof and is of a selected profile or shape such that the contacting connectors of adjacent cells may be overlapped and

  3. Advancements in solar simulators for terrestrial solar cells at high concentration (500 to 5000 Suns) levels

    Microsoft Academic Search

    Doug Jungwirth; Lynne C. Eigler; Steve Espiritu

    2008-01-01

    Testing requirements for high concentration solar cell systems have changed dramatically in the recent past, therefore a new generation of solar cell testers need to be developed to fulfill these testing requirements. This paper reports on one of those new solar cell illuminators. Spectrolab has completed initial evaluation of a Terrestrial-High Intensity Pulsed Solar Simulator (T-HIPSS) [3]. This pulsed illuminator

  4. Solar Energy Materials & Solar Cells 71 (2002) 261271 Photoelectric behavior of nanocrystalline TiO2

    E-print Network

    Huang, Yanyi

    2002-01-01

    photovoltaic converter has been a powerful alternative candidate for conventional silicon solar cells unmatched performance in dye staff studied as solar cell sensitizer before 1997. Only recently, a black dyeSolar Energy Materials & Solar Cells 71 (2002) 261­271 Photoelectric behavior of nanocrystalline Ti

  5. Performance measurement of dye-sensitized solar cells and organic polymer solar cells

    Microsoft Academic Search

    Yoshihiro Hishikawa

    2008-01-01

    Performance characterization of the dye-sensitized solar cells (DSC) and organic polymer solar cells (OSC) has been investigated, in order to clarify how to accurately determine their performance. Accurate characterization of DSC requires consideration on the very slow temporal response, and variation of the quantum efficiency spectrum for the bias light. The I-V curves of the DSC are clearly dependent on

  6. Solar cell radiation handbook. [Degradation of solar cells in space radiation environment

    Microsoft Academic Search

    H. Y. Tada; J. R. Jr. Carter

    1977-01-01

    The purpose of this document is to detail a method of predicting the degradation of a solar array in a space radiation environment. The text contains a discussion of solar cell technology which emphasizes the cell parameters which degrade in a radiation environment. The experimental techniques used in the evaluation of radiation effects are discussed. The theoretical aspects of radiation

  7. Progress in high-efficiency terrestrial concentrator solar cells

    Microsoft Academic Search

    R. K. Jones; P. Hebert; P. Pien; R. R. King; D. Bhusari; R. Brandt; O. Al-Taher; C. Fetzer; J. Ermer

    2009-01-01

    Multijunction solar cells based on III-V semiconductors are the most efficient solar cells in the world, with record efficiencies of over 40%. These devices offer the promise of very competitive solar power systems exploiting the high efficiency devices under high optical concentration. To make this promise a reality, Spectrolab is conducting a multi-year program to develop solar cells with still

  8. Transcending QCD in Nanostructured Solar Cells G. Galli S. Kauzlarich

    E-print Network

    (2012), 31% (2013) (Alta Devices) - Thin films: 19% in CdTe (2013) (First Solar) - Organic solar cellsTranscending QCD in Nanostructured Solar Cells 1 G. Galli S. Kauzlarich F. Gygi S. Carter (UCSC) A Optimization of gap: max efficiency: 31% (Shockley Queisser 1961) In real PV cells 80-85% of incident solar

  9. Absolute indoor calibration of large area solar cells

    Microsoft Academic Search

    J. Metzdorf; T. Wittchen; H. Kaase

    1986-01-01

    Equipment for the calibration of reference solar cells which is traceable back to their primary radiometric standards is presented. The apparatus, based on the differential spectral responsivity method is an absolute indoor procedure without reference solar cells, and needs no solar simulator. The method is applicable to all kinds of test devices up to solar cell areas of 10 x

  10. Third Working Meeting on Gallium Arsenide Solar Cells

    NASA Technical Reports Server (NTRS)

    Walker, G. H. (compiler)

    1976-01-01

    Research results are reported for GaAs Schottky barrier solar cells, GaAlAs/GaAs heteroface solar cells, and GaAlAs graded band gap solar cells. Related materials studies are presented. A systems study for GaAs and Si solar concentrator systems is given.

  11. Advanced Modelling of Silicon Wafer Solar Cells

    NASA Astrophysics Data System (ADS)

    Peters, Marius; Fajun, Ma; Siyu, Guo; Hoex, Bram; Blaesi, Benedikt; Glunz, Stefan; Aberle, Armin; Luther, Joachim

    2012-10-01

    Modelling of solar cells today is general practice in research and widely-used in industry. Established modelling software is typically limited to one dimension and/or to small scales. Additionally, novel effects, like, e.g., the use of diffractive structures or luminescent materials, are not established. In this paper we discuss how the combination of different modelling techniques can be used to overcome these limitations. In this context two examples are presented. The first example concerns the combination of the open source simulation software PC1D with circuit modelling to investigate the effect of local shunts on the global characteristics of a silicon wafer solar cell. For the investigated example (4.5 cm2 cell area) we find that a local point shunt reduces the solar cell efficiency by 4% relative. The second example concerns the modelling of diffractive gratings for thin silicon wafer solar cells. For this purpose, we use the rigorous coupled wave analysis to simulate Sentaurus technical computer-aided design (TCAD) is combined with the rigorous coupled wave analysis, a method to solve Maxwell's equations for periodic structures. Here we show that a grating can be used to improve the absorption in a thin silicon wafer solar cell considerably.

  12. Large area space solar cell assemblies

    Microsoft Academic Search

    M. B. Spitzer; M. J. Nowlan

    1982-01-01

    Development of a large area space solar cell assembly is presented. The assembly consists of an ion implanted silicon cell and glass cover. The important attributes of fabrication are (1) use of a back surface field which is compatible with a back surface reflector, and (2) integration of coverglass application and call fabrication.

  13. Liquid cooled, linear focus solar cell receiver

    DOEpatents

    Kirpich, A.S.

    1983-12-08

    Separate structures for electrical insulation and thermal conduction are established within a liquid cooled, linear focus solar cell receiver for use with parabolic or Fresnel optical concentrators. The receiver includes a V-shaped aluminum extrusion having a pair of outer faces each formed with a channel receiving a string of solar cells in thermal contact with the extrusion. Each cell string is attached to a continuous glass cover secured within the channel with spring clips to isolate the string from the external environment. Repair or replacement of solar cells is effected simply by detaching the spring clips to remove the cover/cell assembly without interrupting circulation of coolant fluid through the receiver. The lower surface of the channel in thermal contact with the cells of the string is anodized to establish a suitable standoff voltage capability between the cells and the extrusion. Primary electrical insulation is provided by a dielectric tape disposed between the coolant tube and extrusion. Adjacent solar cells are soldered to interconnect members designed to accommodate thermal expansion and mismatches. The coolant tube is clamped into the extrusion channel with a releasably attachable clamping strip to facilitate easy removal of the receiver from the coolant circuit.

  14. High-efficiency concentrator silicon solar cells

    SciTech Connect

    Sinton, R.A.; Cuevas, A.; King, R.R.; Swanson, R.M. (Stanford Univ., CA (USA). Solid-State Electronics Lab.)

    1990-11-01

    This report presents results from extensive process development in high-efficiency Si solar cells. An advanced design for a 1.56-cm{sup 2} cell with front grids achieved 26% efficiency at 90 suns. This is especially significant since this cell does not require a prismatic cover glass. New designs for simplified backside-contact solar cells were advanced from a status of near-nonfunctionality to demonstrated 21--22% for one-sun cells in sizes up to 37.5 cm{sup 2}. An efficiency of 26% was achieved for similar 0.64-cm{sup 2} concentrator cells at 150 suns. More fundamental work on dopant-diffused regions is also presented here. The recombination vs. various process and physical parameters was studied in detail for boron and phosphorous diffusions. Emitter-design studies based solidly upon these new data indicate the performance vs design parameters for a variety of the cases of most interest to solar cell designers. Extractions of p-type bandgap narrowing and the surface recombination for p- and n-type regions from these studies have a generality that extends beyond solar cells into basic device modeling. 68 refs., 50 figs.

  15. Liquid cooled, linear focus solar cell receiver

    DOEpatents

    Kirpich, Aaron S. (Broomall, PA)

    1985-01-01

    Separate structures for electrical insulation and thermal conduction are established within a liquid cooled, linear focus solar cell receiver for use with parabolic or Fresnel optical concentrators. The receiver includes a V-shaped aluminum extrusion having a pair of outer faces each formed with a channel receiving a string of solar cells in thermal contact with the extrusion. Each cell string is attached to a continuous glass cover secured within the channel with spring clips to isolate the string from the external environment. Repair or replacement of solar cells is effected simply by detaching the spring clips to remove the cover/cell assembly without interrupting circulation of coolant fluid through the receiver. The lower surface of the channel in thermal contact with the cells of the string is anodized to establish a suitable standoff voltage capability between the cells and the extrusion. Primary electrical insulation is provided by a dielectric tape disposed between the coolant tube and extrusion. Adjacent solar cells are soldered to interconnect members designed to accommodate thermal expansion and mismatches. The coolant tube is clamped into the extrusion channel with a releasably attachable clamping strip to facilitate easy removal of the receiver from the coolant circuit.

  16. Method of fabricating a solar cell array

    DOEpatents

    Lazzery, Angelo G. (Oaklyn, NJ); Crouthamel, Marvin S. (Pennsauken, NJ); Coyle, Peter J. (Oaklyn, NJ)

    1982-01-01

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

  17. Numerical analysis of silicon solar cells

    SciTech Connect

    Lundstrom, M.S.

    1980-01-01

    A set of equations which accurately describes the physics of modern high-efficiency silicon solar cells is formulated and solved numerically. The transport equations of Marshak and van Vliet are recast into a simple. Boltzmann-like form in which the effects associated with the nonuniform band structure and degenerate carrier concentrations are described by two parameters, the effective gap shrinkage and the effective asymmetry factor. The experimental determination of both of these parameters is also discussed. Adler's contention, that some important features of semiconductor device operation can be modeled accurately by using an electically measured effective bandgap shrinkage with an arbitrarily chosen effective asymmetry factor, is also considered. A semiconductor device is described mathematically by Poisson's equation and two current continuity equations. Using the transport equations, these equations were solved numerically in one dimension. The accuracy of the model was tested by comparing the results of computer calculations to exact, analytical results (for certain simple cases) and to experimental results. The model was shown to accurately describe high-efficiency silicon solar cells under a wide range of operating biases and for solar concentrations that varied from 1 to 250. By using the computer model, we were able to explain a physical mechanism which operates to degrade the performance of BSF solar cells operated under high solar concentration. The model was also used to design cells in which the effects of this degradation were minimized. A two-dimensional numerical solar cell model was also developed. An example of the use of this program in analyzing IBC solar cells is presented.

  18. Nanoplasmonics: a frontier of photovoltaic solar cells

    NASA Astrophysics Data System (ADS)

    Gu, Min; Ouyang, Zi; Jia, Baohua; Stokes, Nicholas; Chen, Xi; Fahim, Narges; Li, Xiangping; Ventura, Michael James; Shi, Zhengrong

    2012-12-01

    Nanoplasmonics recently has emerged as a new frontier of photovoltaic research. Noble metal nanostructures that can concentrate and guide light have demonstrated great capability for dramatically improving the energy conversion efficiency of both laboratory and industrial solar cells, providing an innovative pathway potentially transforming the solar industry. However, to make the nanoplasmonic technology fully appreciated by the solar industry, key challenges need to be addressed; including the detrimental absorption of metals, broadband light trapping mechanisms, cost of plasmonic nanomaterials, simple and inexpensive fabrication and integration methods of the plasmonic nanostructures, which are scalable for full size manufacture. This article reviews the recent progress of plasmonic solar cells including the fundamental mechanisms, material fabrication, theoretical modelling and emerging directions with a distinct emphasis on solutions tackling the above-mentioned challenges for industrial relevant applications.

  19. Present status of solid state photoelectrochemical solar cells and dye sensitized solar cells using PEO-based polymer electrolytes

    Microsoft Academic Search

    Pramod Kumar Singh; R K Nagarale; S P Pandey; H W Rhee; Bhaskar Bhattacharya

    2011-01-01

    Due to energy crises in the future, much effort is being directed towards alternate sources. Solar energy is accepted as a novel substitute for conventional sources of energy. Out of the long list of various types of solar cells available on the market, solid state photoelectrochemical solar cells (SSPECs) and dye sensitized solar cells (DSSCs) are proposed as an alternative

  20. Black silicon for solar cell applications

    NASA Astrophysics Data System (ADS)

    Kroll, Matthias; Otto, Martin; Käsebier, Thomas; Füchsel, Kevin; Wehrspohn, Ralf; Kley, Ernst-Bernhard; Tünnermann, Andreas; Pertsch, Thomas

    2012-06-01

    We present experimental results and rigorous numerical simulations on the optical properties of Black Silicon surfaces and their implications for solar cell applications. The Black Silicon is fabricated by reactive ion etching of crystalline silicon with SF6 and O2. This produces a surface consisting of sharp randomly distributed needle like features with a characteristic lateral spacing of about a few hundreds of nanometers and a wide range of aspect ratios depending on the process parameters. Due to the very low reflectance over a broad spectral range and a pronounced light trapping effect at the silicon absorption edge such Black Silicon surface textures are beneficial for photon management in photovoltaic applications. We demonstrate that those light trapping properties prevail upon functionalization of the Black Silicon with dielectric coatings, necessary to construct a photovoltaic system. The experimental investigations are accompanied by rigorous numerical simulations based on three dimensional models of the Black Silicon structures. Those simulations allow insights into the light trapping mechanism and the influence of the substrate thickness onto the optical performance of the Black Silicon. Finally we use an analytical solar cell model to relate the optical properties of Black Silicon to the maximum photo current and solar cell efficiency in dependence of the solar cell thickness. The results are compared to standard light trapping schemes and implications especially for thin solar cells are discussed.

  1. Generating AC With Rotating Solar Cells

    NASA Technical Reports Server (NTRS)

    Flanagan, David T.

    1993-01-01

    Rotating solar photovoltaic cells or batteries connected to suitable mechanical and/or electronic commutators produce nearly sinusoidal alternating current. Eliminates need for inverter circuitry and its attendant power-consumption and heat-dissipation problems, but imposes need for low-power-consumption rotary mechanism. Intended for use aboard spacecraft, also useful in special terrestrial situations where solar electric power must be transmitted over powerlines from one remote location to another.

  2. A light-trapping solar cell coverglass

    Microsoft Academic Search

    Geoffrey A. Landis

    1990-01-01

    A novel method of reducing surface reflectivity which eliminates the need to texturize the surface of the cell is presented. A double light pass is achieved by using a light-trapping coverglass which redirects reflected light back to the cell surface by total internal reflection. This technique allows low-reflectance surfaces to be used on planar solar cells, including GaAs and InP\\/int,

  3. Physics based simulation of dye solar cells

    Microsoft Academic Search

    M. Auf der Maur; A. Gagliardi; A. Di Carlo

    Dye sensitized solar cells are interesting candidates for providing a renewable, cost efficient energy source with low environmental\\u000a impact. The lack of a suitable simulation software to study basic cell properties and to optimize the cell topology is currently\\u000a one of the factors hindering their commercialization. We present in this paper a theoretical model of the entire device based\\u000a on

  4. One-sun silicon solar cell research

    Microsoft Academic Search

    M. A. Green; J. Zhao; A. Wang; A. W. Blakers; A. M. Milne; X. Dai; C. M. Chong; S. R. Wenham; F. Zhang; F. Yun; J. Zolper; S. Narayanan; A. B. Sproul

    1991-01-01

    This report describes research for the period September 1988 to February 1990 directed at improving the performance of crystalline and polycrystalline silicon solar cells. Key results include the demonstration of 24.2 percent energy conversion efficiency for 4-sq cm crystalline cells fabricated using the development of the Passivated Emitter Cell processing sequence, the demonstration of energy conversion efficiency up to 22.4

  5. Plasma Texturing of Silicon Solar Cells

    Microsoft Academic Search

    Mohan Narayanan; Madhu Roy; Douglas S. Ruby; Saleem H. Zaidi

    1999-01-01

    Surface texture promotes enhanced light absorption in Si solar cells. The quality of lower cost multicrystalline-silicon (mc-Si) has increased to the point that its cell performance is close to that of single c-Si cells, with the major difference resulting from the inability to texture mc-Si affordably. This has reduced the cost-per-watt advantage of mc-Si. Surface texturing aimed at enhanced absorption

  6. Advances in solar cell welding technology

    Microsoft Academic Search

    L. G. Chidester; D. R. Lott

    1982-01-01

    In addition to developing the rigid substrate welded conventional cell panels for an earlier U.S. flight program, LMSC recently demonstrated a welded lightweight array system using both 2 x 4 and 5.9 x 5.9 cm wraparound solar cells. This weld system uses infrared sensing of weld joint temperature at the cell contact metalization interface to precisely control weld energy on

  7. Reliability studies on MIS solar cells

    Microsoft Academic Search

    W. A. Anderson; J. K. Kim

    1978-01-01

    Research on Cr\\/oxide\\/p-type Si solar cells has produced a 12.2% efficiency on 2 cm2 area. Reliability studies have been conducted to determine if degradation occurs during use in an extreme environment. Several\\u000a cells with A\\/R coatings and encapsulation have been tested with degradation occurring in some cases after 2 years of use.\\u000a One cell without an A\\/R coating was used

  8. Reliability studies on MIS solar cells

    Microsoft Academic Search

    W. A. Anderson; J. K. Kim

    1978-01-01

    Research on Cr\\/oxide\\/p-type Si solar cells has produced a 12.2% efficiency on 2 sq cm area. Reliability studies have been conducted to determine if degradation occurs during use in an extreme environment. Several cells with A\\/R coatings and encapsulation have been tested with degradation occurring in some cases after 2 years of use. One cell without an A\\/R coating was

  9. Fabricating solar cells with silicon nanoparticles

    SciTech Connect

    Loscutoff, Paul; Molesa, Steve; Kim, Taeseok

    2014-09-02

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

  10. Solar Cell Modules with Parallel Oriented Interconnections

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Twenty-four solar modules, half of which were 48 cells in an all-series electrical configuration and half of a six parallel cells by eight series cells were provided. Upon delivery of environmentally tested modules, low power outputs were discovered. These low power modules were determined to have cracked cells which were thought to cause the low output power. The cracks tended to be linear or circular which were caused by different stressing mechanisms. These stressing mechanisms were fully explored. Efforts were undertaken to determine the causes of cell fracture. This resulted in module design and process modifications. The design and process changes were subsequently implemented in production.

  11. TACSAT-4 solar cell experiment: Advanced solar cell technologies in a high radiation environment

    Microsoft Academic Search

    Phillip Jenkins; Michael Krasowski; Norman Prokop; Robert Walters; D. Spina; M. Eskenazi; R. Skalitzky; T. Duffey; B. Davis; S. Koss; S. Messenger; E. Downard; K. Crist; M. O'Neill; B. Fu; D. Bentz

    2009-01-01

    The TACSAT-4 Solar Cell Experiment will measure the current and voltage characteristics of advanced EMCORE BTJM solar cells thinned to 100 microns and ATJM cells under an 8.5X ENTECH Stretched Lens. TACSAT-4 will fly in a highly elliptical orbit, passing through the electron and proton belts every six hours. This orbit is expected to induce a 25% power reduction in

  12. Space solar cell research - Problems and potential

    NASA Technical Reports Server (NTRS)

    Flood, Dennis J.

    1986-01-01

    The value of a passive, maintenance-free, renewable energy source was immediately recognized in the early days of the space program, and the silicon solar cell, despite its infancy, was quickly pressed into service. Efficiencies of those early space solar arrays were low, and lifetimes shorter than hoped for, but within a decade significant advances had been made in both areas. Better performance was achieved because of a variety of factors, ranging from improvements in silicon single crystal material, to better device designs, to a better understanding of the factors that affect the performance of a solar cell in space. Chief among the latter, particularly for the mid-to-high altitude (HEO) and geosynchronous (GEO) orbits, are the effects of the naturally occurring particulate radiation environment. Although not as broadly important to the photovoltaic community at large as increased efficiency, the topic of radiation damage is critically important to use of solar cells in space, and is a major component of the NASA research program in space photovoltaics. This paper will give a brief overview of some of the opportunities and challenges for space photovoltaic applications, and will discuss some of the current reseach directed at achieving high efficiency and controlling the effects of radiation damage in space solar cells.

  13. Space solar cell research: Problems and potential

    NASA Technical Reports Server (NTRS)

    Flood, D. J.

    1986-01-01

    The value of a passive, maintenance-free, renewable energy source was apparent in the early days of the space program, and the silicon solar cell was pressed into service. Efficiencies of those early space solar arrays were low, and lifetimes shorter than hoped for, but within a decade significant advances had been made in both areas. Better performance was achieved through improvements in silicon single crystal material, better device designs, and a better understanding of the factors that affect the performance of a solar cell in space. Chief among the latter, particularly for the mid-to-high altitude (HEO) and geosynchronous (GEO) orbits, are the effects of the naturally occurring particulate radiation environment. Although not as broadly important to the photovoltaic community at large as increased efficiency, the topic of radiation damage is critically important to use of solar cells in space, and is a major component of the NASA research program in space photovoltaics. A brief overview of some of the opportunities and challenges for space photovoltaic applications is given, and some of the current research directed at achieving high efficiency and controlling radiation damage in space solar cells is discussed.

  14. Modeling of polycrystalline thin film solar cells

    NASA Astrophysics Data System (ADS)

    Fahrenbruch, Alan L.

    1999-03-01

    This paper describes modeling polycrystalline thin-film solar cells using the program AMPS-1D1 to visualize the relationships between the many variables involved. These simulations are steps toward two dimensional modeling the effects of grain boundaries in polycrystalline cells. Although this paper describes results for the CdS/CdTe cell, the ideas presented here are applicable to copper-indium-gallium selenide (CIGS) cells as well as other types of cells. Results of these one-dimensional simulations are presented: (a) the duplication of experimentally observed cell parameters, (b) the effects of back-contact potential barrier height and its relation to stressing the cell, (c) the effects of the depletion layer width in the CdTe layer on cell parameters, and (d) the effects of CdS layer thickness on the cell parameters. Experience using the software is also described.

  15. Amorphous and Microcrystalline Silicon Solar Cells: Preprint

    SciTech Connect

    Wagner, S. (Princeton University); Carlson, D. E. (Solarex); Branz, H. M. (National Renewable Energy Laboratory)

    1999-04-01

    We review the progress made by amorphous silicon solar cells, including the emerging technology of solar cells of microcrystalline silicon. The long-term trend in the efficiency of stabilized laboratory cells based on a-Si:H has been a rise of {approx}0.6 % per year. The recent trend in the a-Si,Ge:H cell efficiency alone, measured in the spectral window assigned to the bottom device in a triple-junction cell, has been an increase of {approx}0.16% per year. These improvements have brought within reach the target of 15% efficiency identified by EPRI and DOE for widespread application. Our review leads to an identification of areas of promising research, with emphasis on the fundamental science required to reach the 15% target, and then to move to the next-level efficiency goal.

  16. Gaalas/Gaas Solar Cell Process Study

    NASA Technical Reports Server (NTRS)

    Almgren, D. W.; Csigi, K. I.

    1980-01-01

    Available information on liquid phase, vapor phase (including chemical vapor deposition) and molecular beam epitaxy growth procedures that could be used to fabricate single crystal, heteroface, (AlGa) As/GaAs solar cells, for space applications is summarized. A comparison of the basic cost elements of the epitaxy growth processes shows that the current infinite melt LPE process has the lower cost per cell for an annual production rate of 10,000 cells. The metal organic chemical vapor deposition (MO-CVD) process has the potential for low cost production of solar cells but there is currently a significant uncertainty in process yield, i.e., the fraction of active material in the input gas stream that ends up in the cell. Additional work is needed to optimize and document the process parameters for the MO-CVD process.

  17. Modeling and analysis of cascade solar cells

    NASA Astrophysics Data System (ADS)

    Ho, F. D.

    1986-01-01

    A brief review is given of the present status of the development of cascade solar cells. It is known that photovoltaic efficiencies can be improved through this development. The designs and calculations of the multijunction cells, however, are quite complicated. The main goal is to find a method which is a compromise between accuracy and simplicity for modeling a cascade solar cell. Three approaches are presently under way, among them (1) equivalent circuit approach, (2) numerical approach, and (3) analytical approach. Here, the first and the second approaches are discussed. The equivalent circuit approach using SPICE (Simulation Program, Integrated Circuit Emphasis) to the cascade cells and the cascade-cell array is highlighted. The methods of extracting parameters for modeling are discussed.

  18. Multi-junction solar cell device

    DOEpatents

    Friedman, Daniel J. (Lakewood, CO); Geisz, John F. (Wheat Ridge, CO)

    2007-12-18

    A multi-junction solar cell device (10) is provided. The multi-junction solar cell device (10) comprises either two or three active solar cells connected in series in a monolithic structure. The multi-junction device (10) comprises a bottom active cell (20) having a single-crystal silicon substrate base and an emitter layer (23). The multi-junction device (10) further comprises one or two subsequent active cells each having a base layer (32) and an emitter layer (23) with interconnecting tunnel junctions between each active cell. At least one layer that forms each of the top and middle active cells is composed of a single-crystal III-V semiconductor alloy that is substantially lattice-matched to the silicon substrate (22). The polarity of the active p-n junction cells is either p-on-n or n-on-p. The present invention further includes a method for substantially lattice matching single-crystal III-V semiconductor layers with the silicon substrate (22) by including boron and/or nitrogen in the chemical structure of these layers.

  19. Flexible implementation of rigid solar cell technologies.

    SciTech Connect

    Hollowell, Andrew E.

    2010-08-01

    As a source of clean, remote energy, photovoltaic (PV) systems are an important area of research. The majority of solar cells are rigid materials with negligible flexibility. Flexible PV systems possess many advantages, such as being transportable and incorporable on diverse structures. Amorphous silicon and organic PV systems are flexible; however, they lack the efficiency and lifetime of rigid cells. There is also a need for PV systems that are light weight, especially in space and flight applications. We propose a solution to this problem by arranging rigid cells onto a flexible substrate creating efficient, light weight, and flexible devices. To date, we have created a working prototype of our design using the 1.1cm x 1cm Emcore cells. We have achieved a better power to weight ratio than commercially available PowerFilm{reg_sign}, which uses thin film silicon yielding .034W/gram. We have also tested our concept with other types of cells and verified that our methods are able to be adapted to any rigid solar cell technology. This allows us to use the highest efficiency devices despite their physical characteristics. Depending on the cell size we use, we can rival the curvature of most available flexible PV devices. We have shown how the benefits of rigid solar cells can be integrated into flexible applications, allowing performance that surpasses alternative technologies.

  20. Solar cell contact formation using laser ablation

    DOEpatents

    Harley, Gabriel; Smith, David D.; Cousins, Peter John

    2014-07-22

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

  1. Solar cell contact formation using laser ablation

    DOEpatents

    Harley, Gabriel; Smith, David; Cousins, Peter

    2012-12-04

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

  2. Solar cell contact resistance - a review

    SciTech Connect

    Schroder, D.K.; Meier, D.L.

    1984-05-01

    An overview of ohmic contacts on solar cells is presented. The fundamentals of metal-semiconductor contacts are reviewed, including the Schottky approach, Fermi level pinning by surface states, and the mechanisms of thermionic emission, thermionic/field emission, and tunneling for current transport. The concept of contact resistance is developed and contact resistance data for several different contact materials on both silicon and gallium arsenide over a range of doping densities are summarized. Finally, the requirements imposed by solar cells on contact resistance are detailed.

  3. Origami-enabled deformable silicon solar cells

    SciTech Connect

    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.

  4. Impedance spectroscopic characterization of solar cell

    NASA Astrophysics Data System (ADS)

    Gautham, S.; Ramanathan, S.

    2014-10-01

    Impedance spectroscopy is used to characterize a commercial solar cell, at various dc bias potentials, under illumination and dark conditions. Interesting features are observed in medium and low frequency range, at large bias potentials. All the models reported in literature utilize combinations of resistances and capacitances, but the results indicate that inductances are necessary to model the actual solar cell, since an inductive loop is observed in the medium frequency range, especially at large bias potential, both under illumination and dark conditions. A new circuit which captures all the trends semi quantitatively is proposed to model the data.

  5. Design and fabrication of solar cell modules

    NASA Technical Reports Server (NTRS)

    Shaughnessy, T. P.

    1978-01-01

    A program conducted for design, fabrication and evaluation of twelve silicon solar cell modules is described. The purpose of the program was to develop a module design consistent with the requirements and objectives of JPL specification and to also incorporate elements of new technologies under development to meet LSSA Project goals. Module development emphasized preparation of a technically and economically competitive design based upon utilization of ion implanted solar cells and a glass encapsulation system. The modules fabricated, tested and delivered were of nominal 2 X 2 foot dimensions and 20 watt minimum rating. Basic design, design rationale, performance and results of environmental testing are described.

  6. Stratospheric NO and NO2 profiles at sunset from analysis of high-resolution balloon-borne infrared solar absorption spectra obtained at 33 deg N and calculations with a time-dependent photochemical model

    SciTech Connect

    Rinsland, C.P.; Boughner, R.E.; Larsen, J.C.; Goldman, A.

    1984-08-01

    Simultaneous stratospheric vertical profiles of NO and NO2 at sunset were derived from an analysis of infrared solar absorption spectra recorded from a float altitude of 33 km with an interferometer system during a balloon flight. A nonlinear least squares procedure was used to analyze the spectral data in regions of absorption by NO and NO2 lines. Normalized factors, determined from calculations of time dependent altitude profiles with a detailed photochemical model, were included in the onion peeling analysis to correct for the rapid diurnal changes in NO and NO2 concentrations with time near sunset. The CO2 profile was also derived from the analysis and is reported.

  7. Requirements for a large area solar simulator regarding the measurement of MJ solar cells

    Microsoft Academic Search

    Ralf Adelhelm; Detlev Berger

    2003-01-01

    The absolute electrical power measurement of a multi-junction (MJ) solar cell device requires high quality for the solar simulator, especially in terms of the generated uniformity and the spectral match of the irradiance, but also for the knowledge of the technical specifications of the MJ solar cell. As the uncertainty of the measurement of a solar array combines many geometrical,

  8. Accelerated/abbreviated test methods for predicting life of solar cell encapsulants to Jet Propulsion Laboratory California Institute of Technology for the encapsulation task of the low-cost solar array project

    NASA Technical Reports Server (NTRS)

    Kolyer, J. M.

    1978-01-01

    An important principle is that encapsulants should be tested in a total array system allowing realistic interaction of components. Therefore, micromodule test specimens were fabricated with a variety of encapsulants, substrates, and types of circuitry. One common failure mode was corrosion of circuitry and solar cell metallization due to moisture penetration. Another was darkening and/or opacification of encapsulant. A test program plan was proposed. It includes multicondition accelerated exposure. Another method was hyperaccelerated photochemical exposure using a solar concentrator. It simulates 20 year of sunlight exposure in a short period of one to two weeks. The study was beneficial in identifying some cost effective encapsulants and array designs.

  9. Harmful Shunting Mechanisms Found in Silicon Solar Cells (Fact Sheet)

    SciTech Connect

    Not Available

    2011-05-01

    Scientists developed near-field optical microscopy for imaging electrical breakdown in solar cells and identified critical electrical breakdown mechanisms operating in industrial silicon and epitaxial silicon solar cells.

  10. Growth and characterization of cascade solar cells

    Microsoft Academic Search

    S. M. Bedair; M. L. Timmons; M. Simons

    1981-01-01

    Monolithic, two-junction cascade solar cells are fabricated in two different III-V materials systems: Al-Ga-As and Al-Ga-As-Sb. The Al-Ga-As system employs a GaAs low bandgap cell and a 1.9 eV AlGaAs high bandgap cell connected by an AlGaAs tunnel junction, and although the cell does not possess the optimum bandgap values for maximum efficiency, it is attractive from a developmental standpoint

  11. 23.9% monolithic multijunction solar cell

    Microsoft Academic Search

    G. F. Virshup; B.-C. Chung; J. G. Werthen

    1988-01-01

    A monolithically grown two-junction solar cell has been fabricated which produces 23.9% efficiency under AM1.5 global conditions and 22.3% under AM0 conditions. These are the highest one-sun efficiencies reported to date for both AM0 and AM1.5. The Al.35Ga.65As (1.93 eV) top cell and the GaAs (1.42 eV) bottom cell were grown by metal-organic chemical vapor deposition on GaAs substrates. Cell

  12. Reverse bias degradation in dye solar cells

    NASA Astrophysics Data System (ADS)

    Mastroianni, Simone; Lanuti, Alessandro; Brown, Thomas M.; Argazzi, Roberto; Caramori, Stefano; Reale, Andrea; Di Carlo, Aldo

    2012-09-01

    A prolonged reverse bias (RB) stress forcing a short-circuit current through a dye solar cell, corresponding to the harshest test a shadowed cell may experience in real conditions, can cause the RB operating voltage VRB to drift with time, initially slowly but accelerating for VRB < (-1.65 ± 0.15)V when gas bubbles, identified as H2 (gas chromatography), are produced inside the cell, leading to breakdown. A close connection between VRB, cell performance, and stability was established. Contributions to RB degradation include triiodide depletion and impurities, in particular water. Acting upon these components and setting up protection strategies is important for delivering long-lasting modules.

  13. Photochemical Synthesis of Nepetanudone.

    PubMed

    Jayan, Swapna; Jones, Paul B

    2015-06-26

    Nepetanudone and nepetaparnone have been suspected of being the products of a photochemical dimerization of nepetapyrone. Both are natural products found in a variety of Nepeta species. The synthesis of (±)-nepetapyrone and subsequent photochemical experiments are described. (±)-Nepetanudone was produced upon irradiation of (±)-nepetapyrone, while (±)-nepetaparnone, a diastereomer of nepetanudone, was not observed. PMID:25978278

  14. Studies of silicon pn junction solar cells

    NASA Technical Reports Server (NTRS)

    Lindholm, F. A.; Neugroschel, A.

    1977-01-01

    Modifications of the basic Shockley equations that result from the random and nonrandom spatial variations of the chemical composition of a semiconductor were developed. These modifications underlie the existence of the extensive emitter recombination current that limits the voltage over the open circuit of solar cells. The measurement of parameters, series resistance and the base diffusion length is discussed. Two methods are presented for establishing the energy bandgap narrowing in the heavily-doped emitter region. Corrections that can be important in the application of one of these methods to small test cells are examined. Oxide-charge-induced high-low-junction emitter (OCI-HLE) test cells which exhibit considerably higher voltage over the open circuit than was previously seen in n-on-p solar cells are described.

  15. Direct-Write Contacts for Solar Cells

    SciTech Connect

    Kaydanova, T.; van Hest, M.F.A.M.; Miedaner, A.; Curtis, C. J.; Alleman, J. L.; Dabney, M. S.; Garnett, E.; Shaheen, S.; Ginley, D. S.; Smith, L.; Collins, R.; Hanoka, J. I.; Gabor, A. M.

    2005-01-01

    We report on our project to develop inkjet printable contacts for solar cells. Ag, Cu, and Ni metallizations were inkjet printed with near vacuum deposition quality. Thick, highly conducting lines of Ag and Cu demonstrating good adhesion to glass, Si, and PCB have been printed at 100-200 C in air and N2, respectively. Ag grids were inkjet-printed on Si solar cells and fired through silicon nitride AR layer at 850 C resulting in 8% cells. Next-generation multicomponent inks (including etching agents) have also been developed with improved fire-through contacts leading to higher cell efficiencies. The approach developed can be easily extended to other conductors such as Pt, Pd, and Au, etc. In addition, PEDOT-PSS polymer-based conductors were inkjet-printed with the conductivity as good or better than those of polymer-based conductors.

  16. Center punched solar cell module development effort

    NASA Technical Reports Server (NTRS)

    Ross, R. E.; Mortensen, W. E.

    1978-01-01

    The results are given of an advanced module development program with the objective of providing a low cost solar cell mechanical interconnect design. The design approach, which avoids soldering or welding operations, lends itself to automated assembly techniques thus supporting the Low-Cost Silicon Solar Array Project goals. The first group of six modules contained aluminum contact cells and the second group of six modules contained silver-titanium-palladium contact cells. Extensive component and environmental testing at the module level showed that reliable cell mechanical interconnection can be achieved when utilizing the proper electrical contact materials and pressures. A discussion is given of the module design, manufacturing procedure, test program, significant problem areas and solutions, and conclusions and recommendations as formulated and conducted by XEOS.

  17. High-performance silicon nanohole solar cells.

    PubMed

    Peng, Kui-Qing; Wang, Xin; Li, Li; Wu, Xiao-Ling; Lee, Shuit-Tong

    2010-05-26

    We demonstrate Si nanohole arrays as a superior sunlight-absorbing nanostructure for photovoltaic solar cell applications. Under 1 sun AM1.5G illumination, a Si nanohole solar cell with p-n junctions via P diffusion exhibited a open-circuit voltage of 566.6 mV, a short-circuit current density of 32.2 mA/cm(2), and a remarkable power conversion efficiency of 9.51%, which is higher than that of its counterparts based on Si nanowires, planar Si, and pyramid-textured Si. The nanohole array geometry presents a novel and viable method fo cost-efficient solar energy conversion. PMID:20426468

  18. Solar cell calibration for the Pico Satellite solar cell testbed (PSSC Testbed) space flight experiment

    Microsoft Academic Search

    Edward J. Simburger; Simon Liu; John Halpine; David Hinkley; Daniel Rumsey; James Swenson; Jennifer Granata; Henry Yoo

    2008-01-01

    The results of this preflight calibration of the measurement electronics and the individual solar arrays will allow corrections to be made to flight data for determining the actual degradation of the test solar cells as a result of exposure to the space environment.

  19. Solar module using dye-sensitized solar cells with a polymer electrolyte

    Microsoft Academic Search

    Jilian Nei de Freitas; Claudia Longo; Ana Flávia Nogueira; Marco-Aurelio De Paoli

    2008-01-01

    Dye-sensitized TiO2 solar cells assembled with a polymer electrolyte were investigated, aiming at the construction of an 8V solar module. The individual solar cells were assembled with 4.5cm2 active area and were characterized under outdoor conditions, exhibiting an average efficiency of 0.9% per cell (at 12:00 noon). The solar module was built by connecting 13 cells in series. The integrated

  20. High-efficiency silicon solar cells

    Microsoft Academic Search

    M. A. Green; A. W. Blakers; Jiqun Shi; E. M. Keller; S. R. Wenham

    1984-01-01

    Silicon solar cells are described which operate at energy conversion efficiencies independently measured at 18.7 percent under standard terrestrial test conditions (AM1.5, 100 mW\\/cm², 28°C). These are apparently the most efficient silicon cells fabricated to date. The high-efficiency results from a combination of high open-circuit voltage due to the careful attention paid to the passivation of the top surface of

  1. Detailed balance limit for solar cell efficiency

    Microsoft Academic Search

    Hans J. Queisser

    2009-01-01

    The principle of detailed balance was used in 1960 to derive a thermodynamic limit for energy conversion efficiency of semiconductor junction photovoltaic cells. Absorption and emission of photons must be balanced, the cell being a black body. Non-radiative recombinations of solar-generated electron–hole pairs are thus particularly deleterious, affecting silicon junctions. Gallium arsenide, however, is inherently more efficient because of its

  2. Thin film solar cells for terrestrial applications

    Microsoft Academic Search

    F. A. Shirland; W. J. Biter; E. W. Greeneich; T. P. Brody

    1975-01-01

    The goals of the project are to develop a terrestrial version of the CdS thin film solar cell that is demonstrably amenable to low cost mass production, and to establish data on the lifetime of such cells under the expected conditions of terrestrial use. There were six major tasks for the first year's work. These were: Re-establish the state-of-the-art of

  3. The analysis and optimization of a spherical silicon solar cell 

    E-print Network

    McKee, William Randall

    1976-01-01

    . Material parameters for n and p-type base and diffused layers 29 EIST OF FIGURES figure 1. Model for vertical multi-junction solar cell page 2. Comparison of the spherical, cubic and cylindrical solar cell geometries 3. Refraction of light... be other means to increase the collection efficiency without improving the solar cell material. The vertical multi- junction solar cell is an example of a geometry change which could reduce collection losses to negligible levels, This geometry has been...

  4. Space solar cells - High efficiency and radiation damage

    Microsoft Academic Search

    H. W. Brandhorst Jr.; D. T. Bernatowicz

    1980-01-01

    The proceedings of the Third Solar Cell High Efficiency and Radiation Damage Meeting are outlined. The topics covered included high efficiency silicon solar cells, silicon solar cell radiation damage, GaAs solar cell performance, and 30 percent conversion devices. The study of radiation damage from a fundamental defect-centered basis is discussed and evaluated as a focus of future work. 18% AM0

  5. Thin crystalline silicon solar cells with metallic back reflector

    Microsoft Academic Search

    C. Paola Murcia; Ruiying Hao; Christopher Leitz; Anthony Lochtefeld; Allen Barnett

    2011-01-01

    Thin-film crystalline silicon (c-Si) solar cells have the potential for very high efficiency through high open circuit voltage (Voc) [1]. The best performance reported in thin-film crystalline silicon solar cells with absorber thickness below 20 microns is 16.9% efficiency for a solar cell grown epitaxially on a crystalline silicon conductive substrate [2]. The efficiency potential of thin c-Si solar cells

  6. Wide gap chalcopyrites: material properties and solar cells

    Microsoft Academic Search

    Susanne Siebentritt

    2002-01-01

    Solar cells made from wide gap chalcopyrites have received considerable interest due to the fact that high open circuit voltages are desirable for thin film modules and due to the goal to develop tandem solar cells. Although on theoretical grounds efficiencies of CuInS2 and CuGaSe2 solar cells should be comparable to Cu(In,Ga)Se2 solar cells, so far, actual efficiencies are considerably

  7. Improved performance design of gallium arsenide solar cells for space

    Microsoft Academic Search

    R. H. Parekh; A. M. Barnett

    1984-01-01

    Two gallium arsenide solar cell configurations have evolved over the last decade--the heteroface solar cell which uses a (GaAl) as surface passivating layer over a p-n solar cell; and a n\\/sup +\\/-p-p\\/sup +\\/ shallow homojunction solar cell. Energy conversion efficiencies of 18.8 percent have been reported with the heteroface structure. In this paper, we report an improved design, shallow junction

  8. Efficiency limits for space multi-junction concentrator solar cells

    Microsoft Academic Search

    Ma Shaodong; Peng Hongling; Chen Wei; Jiang Bin; Zheng Wanhua

    2011-01-01

    Efficiency limits of single-junction and multi-junction concentrator solar cells are established from the thermodynamic principle of detailed balance. The maximum efficiency limit of single-junction solar cells is 35% at 500 suns, while that of 2-junction solar cells which meet the current matching condition is 46%. At the same condition, the maximum efficiency limit of 3-junction solar cells with GaAs as

  9. Concepts of inorganic solid-state nanostructured solar cells

    Microsoft Academic Search

    Thomas Dittrich; Abdelhak Belaidi; Ahmed Ennaoui

    2011-01-01

    The development of inorganic solid-state nanostructured solar cells over the last years has been reviewed with respect to concepts and materials. Major attention has been paid to solar cells with extremely thin absorber, solar cells with ultra-thin nano-composite absorber and solar cells with quantum dot absorber layers. The focus has been set to structured transparent electron conductors and absorber materials

  10. Photochemical Escape of Oxygen from Early Mars

    E-print Network

    Zhao, Jinjin

    2015-01-01

    Photochemical escape is an important process for oxygen escape from present Mars. In this work, a 1-D Monte-Carlo Model is developed to calculate escape rates of energetic oxygen atoms produced from O2+ dissociative recombination reactions (DR) under 1, 3, 10, and 20 times present solar XUV fluxes. We found that although the overall DR rates increase with solar XUV flux almost linearly, oxygen escape rate increases from 1 to 10 times present solar XUV conditions but decreases when increasing solar XUV flux further. Analysis shows that atomic species in the upper thermosphere of early Mars increases more rapidly than O2+ when increasing XUV fluxes. While the latter is the source of energetic O atoms, the former increases the collision probability and thus decreases the escape probability of energetic O. Our results suggest that photochemical escape be a less important escape mechanism than previously thought for the loss of water and/or CO2 from early Mars.

  11. Solar cell angle of incidence corrections

    Microsoft Academic Search

    Dale R. Burger; Robert L. Mueller

    1995-01-01

    Literature on solar array angle of incidence corrections was found to be sparse and contained no tabular data for support. This lack along with recent data on 27 GaAs\\/Ge 4 cm by 4 cm cells initiated the analysis presented in this paper. The literature cites seven possible contributors to angle of incidence effects: cosine, optical front surface, edge, shadowing, UV

  12. Phthalocyanine blends improve bulk heterojunction solar cells.

    PubMed

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

    2010-03-01

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

  13. Organic solar cells using inverted layer sequence

    Microsoft Academic Search

    M. Glatthaar; M. Niggemann; B. Zimmermann; P. Lewer; M. Riede; A. Hinsch; J. Luther

    2005-01-01

    We report on a concept for organic solar cells where the layer sequence is inverted compared to the conventional setup. In such a configuration a conducting polymer layer is used as the transparent anode which is able to transport the photocurrent laterally to a metal grid. For the anode a low sheet resistance and a work function matching approximately the

  14. Physics based simulation of dye solar cells

    Microsoft Academic Search

    M. Auf der Maur; A. Gagliardi; A. Di Carlo

    2010-01-01

    Dye sensitized solar cells (DSCs) are interesting candidates for providing a renewable, cost efficient energy source with low environmental impact. Although DSCs are very close to be commercialized, many issues still need to be addressed. Part of the problem is related to the lack of a reliable and consistent simulator able to catch the physics underlying the functioning of the

  15. First large-area dye solar cells

    Microsoft Academic Search

    Toby B. Meyer; Assef Azam; Andreas F. Meyer

    2004-01-01

    For the first time, large area nanocrystalline titanium oxide based Dye Solar Cell modules with a size up to 45 x 45 cm have been manufactured with industrial methods and materials, opening a way to real products for selected markets. The electrical performances are measured, efficiency and stability are addressed, as well as the economic data showing an excellent cost

  16. Plasmonics in Thin Film Solar Cells

    Microsoft Academic Search

    Stephan Fahr; Carsten Rockstuhl; Falk Lederer

    2009-01-01

    Thin film solar cells made of amorphous or microcrystalline silicon provide renewable energy at the benefits of low material consumption. As a drawback, these materials don't offer the high carrier mobilities of their crystalline counterpart. Due to low carrier mobilities, increased process times and material consumption, thick absorbing layers have to be avoided. For maintaining the absorption of the impinging

  17. Gallium arsenide solar cell radiation damage study

    Microsoft Academic Search

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

    1989-01-01

    An analysis has been made of electrons and proton damaged GaAs solar cells suitable for use in space. The authors find that although some electrical parametric data and spectral response data are quite similar, the type of damage due to the two types of radiation is different. An I - V analysis model shows that electrons damage the bulk of

  18. Gallium arsenide solar cell radiation damage study

    Microsoft Academic Search

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

    1989-01-01

    A thorough analysis has been made of electron- and proton- damaged GaAs solar cells suitable for use in space. It is found that, although some electrical parametric data and spectral response data are quite similar, the type of damage due to the two types of radiation is different. An I-V analysis model shows that electrons damage the bulk of the

  19. Solar cell contact resistance - a review

    Microsoft Academic Search

    D. K. Schroder; D. L. Meier

    1984-01-01

    An overview of ohmic contacts on solar cells is presented. The fundamentals of metal-semiconductor contacts are reviewed, including the Schottky approach, Fermi level pinning by surface states, and the mechanisms of thermionic emission, thermionic\\/field emission, and tunneling for current transport. The concept of contact resistance is developed and contact resistance data for several different contact materials on both silicon and

  20. Porous silicon application in solar cell technology

    Microsoft Academic Search

    K. Grigoras; Arunas Krotkus; V. Pacebutas; I. Simkiene

    1998-01-01

    Possible and already realized applications of porous silicon (PS) layers in silicon solar cell technology are overviewed. Four main directions are marked for PS incorporation: (1) heterojunction formation, (2) light trapping, (3) antireflection coating, and (4) surface passivation. Standard PS preparation technique is discussed and a new one is proposed, applicable for large area devices. Optical and electric parameters of

  1. Modeling large-area solar cells

    Microsoft Academic Search

    B. Kippelen; S. Choi; W. J. Potscavage

    2010-01-01

    In this talk we will discuss the modeling of large-area organic solar cells. Degradation of the performance with increased area is observed and analyzed in terms of the power loss density concept. The equivalent circuit model is used to verify that a change in power loss density (or RSA) can have a strong influence on device performance. The limited sheet

  2. Modelling real photovoltaic solar cell using Maple

    Microsoft Academic Search

    S. Aazou; E. M. Assaid

    2009-01-01

    In this paper, Maple software is used to study a solar cell modelled by an electronic circuit containing five physical parameters. The physical parameters are: the series resistance, the shunt resistance, the diode reverse saturation current, the diode ideality factor and the photocurrent (see figure 1). First, the characteristic equation is solved in order to find the output current as

  3. Fluorescent window for liquid junction solar cells

    Microsoft Academic Search

    M. S. Kazacos; E. J. McHenry; A. Heller; B. Miller

    1980-01-01

    To recover part of the often substantial fraction of the sunlight lost in practical semiconductor-liquid junction solar cells by solution absorption, two designs incorporating fluorescent windows are analyzed and tested. In these schemes the luminescers absorb incident light in regions of electrolyte absorption and re-emit at wavelengths both within the semiconductor band gap and the transparent range of the solution.

  4. Design and fabrication of solar cell modules

    Microsoft Academic Search

    T. P. Shaughnessy

    1978-01-01

    A program conducted for design, fabrication and evaluation of twelve silicon solar cell modules is described. The purpose of the program was to develop a module design consistent with the requirements and objectives of JPL specification and to also incorporate elements of new technologies under development to meet LSSA Project goals. Module development emphasized preparation of a technically and economically

  5. Accurate performance measurement of silicon solar cells

    E-print Network

    Accurate performance measurement of silicon solar cells William Murray Keogh July 2001 A thesis published or written by another person has been included in this thesis, except where due reference is made but the most careful simulator measurements. Periodic outdoor calibrations under natural sunlight can therefore

  6. Solar cell design for avoiding LILT degradation

    Microsoft Academic Search

    P. M. Stella; G. T. Ctorry

    1987-01-01

    Growing concerns about radioisotope thermoelectric generator (RTG) performance potential, cost, safety, and availability have renewed interest in utilizing photovoltaic energy conversion for future JPL interplanetary missions such as the Mariner Mark II set. Although lightweight solar array technology has advanced to the point where it would appear to provide an alternative power source, anomalous silicon cell curve shape degradation at

  7. A Photoelectrochemical Solar Cell: An Undergraduate Experiment.

    ERIC Educational Resources Information Center

    Boudreau, Sharon M.; And Others

    1983-01-01

    Preparation and testing of a cadmium selenide photoelectrical solar cell was introduced into an environmental chemistry course to illustrate solid state semiconductor and electrochemical principles. Background information, procedures, and results are provided for the experiment which can be accomplished in a three- to four-hour laboratory session…

  8. Analysis of Multijunction solar cells: Electroluminescence study

    Microsoft Academic Search

    S. Makham; M. Zazoui; J. C. Bourgoin

    2004-01-01

    This paper describes the principle of the study which is based on electroluminescence to extract the parameters characterizing the recombination centers induced by irradiation in a solar cell. This technique is able to provide direct information on each individual junction constituting the multijonctions. The results are compared with those obtained by electrical methods.

  9. Surface modelling of organic solar cells

    Microsoft Academic Search

    M. Chakaroun; B. Ratier; A. Moliton; W. Hojeij; M. Aubourg

    2009-01-01

    Modelling of physical phenomena in optoelectronic devices enables to define new strategies to optimize organic components (organic photovoltaic cells (OPVs), organic light emitting diodes (OLEDs), etc ....). The organic photovoltaic technology allows producing more attractive and lighter weight photovoltaic devices than silicon solar technology. Both organic small molecule based and polymer based devices are studied. These devices needs the use

  10. Pico Satellite Solar Cell Testbed (PSSC Testbed)

    Microsoft Academic Search

    Edward J. Simburger; Simon Liu; John Halpine; David Hinkley; Joseph R. Srour; Daniel Rumsey

    2006-01-01

    The proposed PSSC Testbed flight experiment is designed to obtain space environmental degradation data for advanced solar cells. The purpose of the first flight (International Space Station orbit) is to develop and operationally test the picosatellite and associated ground station. Subsequent flights will be in a GEO transfer orbit, which will provide accelerated radiation degradation data for missions to geosynchronous

  11. Plastic Schottky barrier solar cells

    DOEpatents

    Waldrop, James R. (Thousand Oaks, CA); Cohen, Marshall J. (Thousand Oaks, CA)

    1984-01-24

    A photovoltaic cell structure is fabricated from an active medium including an undoped, intrinsically p-type organic semiconductor comprising polyacetylene. When a film of such material is in rectifying contact with a magnesium electrode, a Schottky-barrier junction is obtained within the body of the cell structure. Also, a gold overlayer passivates the magnesium layer on the undoped polyacetylene film.

  12. High efficiency crystalline silicon solar cells

    NASA Technical Reports Server (NTRS)

    Sah, C. Tang

    1986-01-01

    A review of the entire research program since its inception ten years ago is given. The initial effort focused on the effects of impurities on the efficiency of silicon solar cells to provide figures of maximum allowable impurity density for efficiencies up to about 16 to 17%. Highly accurate experimental techniques were extended to characterize the recombination properties of the residual imputities in the silicon solar cell. A numerical simulator of the solar cell was also developed, using the Circuit Technique for Semiconductor Analysis. Recent effort focused on the delineation of the material and device parameters which limited the silicon efficiency to below 20% and on an investigation of cell designs to break the 20% barrier. Designs of the cell device structure and geometry can further reduce recombination losses as well as the sensitivity and criticalness of the fabrication technology required to exceed 20%. Further research is needed on the fundamental characterization of the carrier recombination properties at the chemical impurity and physical defect centers. It is shown that only single crystalline silicon cell technology can be successful in attaining efficiencies greater than 20%.

  13. New Materials for Chalcogenide Based Solar Cells

    NASA Astrophysics Data System (ADS)

    Tosun, Banu Selin

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

  14. Multijunction Solar Cells on Epitaxial Templates

    NASA Astrophysics Data System (ADS)

    Archer, Melissa Jane

    Future ultrahigh efficiency multijunction solar cells will employ designs that feature three or four or more subcells utilizing lattice-mismatched structures to achieve an optimal band gap sequence for solar energy conversion. While lattice-mismatched multijunction cells have been fabricated recently using metamorphic growth approaches, use of direct wafer bonding techniques to enable lattice mismatch accommodation at the subcell interfaces allows considerably more design freedom and inherently higher-quality, defect-free active regions. This thesis presents new results on wafer bonding and layer transfer for integration of materials with large lattice mismatch, as well as modeling work to better understand the key material parameters in the design of new multijunction solar cells. GaInP/GaAs dual junction solar cells on Ge/Si templates were fabricated using wafer bonding and ion implantation induced layer transfer techniques. Following layer transfer, the surface of the ˜1.4 mum thick transferred Ge(100) has an as-transferred RMS roughness of ˜20 nm and a near surface layer containing a high density of ion implantation-induced defects. The RMS roughness has been reduced to <1 nm. In addition, the effects of changing the strain state of the template substrate on the performance of the devices has been explored by comparing devices grown on Ge/Si and Ge/sapphire. The CTE mismatch between Si and GaAs/GaInP materials induces a tensile strain, whereas the sapphire substrate induces a compressive strain. An analytical p-n junction device physics model for GaInP/GaAs/InGaAsP/InGaAs four junction solar cells was developed. Real behavior of solar cells is accounted for by including: free carrier absorption, temperature and doping effects on carrier mobility, as well as two recombination pathways: Shockley-Read-Hall recombination from a single mid gap trap level and surface recombination. Upper bounds set by detailed balance calculations can be approached by letting the parameters approach ideal conditions. Detailed balance calculations always benefit from added subcells, current matching requirements in series connected p-n multijunctions indicate a minimum performance required from added subcells for net contribution to the overall device. This model allows novel solar cell structures to be evaluated by providing realistic predictions of the performance limitations of these multijunction devices.

  15. Space solar cell technology development - A perspective

    NASA Technical Reports Server (NTRS)

    Scott-Monck, J.

    1982-01-01

    The developmental history of photovoltaics is examined as a basis for predicting further advances to the year 2000. Transistor technology was the precursor of solar cell development. Terrestrial cells were modified for space through changes in geometry and size, as well as the use of Ag-Ti contacts and manufacture of a p-type base. The violet cell was produced for Comsat, and involved shallow junctions, new contacts, and an enhanced antireflection coating for better radiation tolerance. The driving force was the desire by private companies to reduce cost and weight for commercial satellite power supplies. Liquid phase epitaxial (LPE) GaAs cells are the latest advancement, having a 4 sq cm area and increased efficiency. GaAs cells are expected to be flight ready in the 1980s. Testing is still necessary to verify production techniques and the resistance to electron and photon damage. Research will continue in CVD cell technology, new panel technology, and ultrathin Si cells.

  16. Development of a shingle-type solar cell module

    Microsoft Academic Search

    N. F. Shepard Jr.; L. E. Sanchez

    1978-01-01

    The development of a solar cell module, which is suitable for use in place of shingles on the sloping roofs of residental or commercial buildings, is reported. The design consists of nineteen series-connected 53 mm diameter solar cells arranged in a closely packed hexagon configuration. The shingle solar cell module consists of two basic functional parts: an exposed rigid portion

  17. A nature compatible intelligent control system for solar cell

    Microsoft Academic Search

    Dong Jing; Sun Fengchi; Wu Tao

    2008-01-01

    This paper propose and implement a control system for pose control and state monitoring of the solar cell panel. A control model is established for the solar cell panel to adapt to the change of Sunlight in natural environment based on the relative movement between the sun and the earth. It enables the solar cell panel follow the movement of

  18. Investigating the efficiency of Silicon Solar cells at

    E-print Network

    Attari, Shahzeen Z.

    at the moment. What we need to do is to increase solar cell efficiency and cheaper to make using new energy is converted to electrical energy [2]. In this experiment we used a silicon solar cell (boughtInvestigating the efficiency of Silicon Solar cells at different temperatures and wavelengths

  19. Dielectric Waveguides and their Use in Solar Cells Zachariah Peterson

    E-print Network

    La Rosa, Andres H.

    Dielectric Waveguides and their Use in Solar Cells Zachariah Peterson ABSTRACT In this paper, I trapping in solar cells will be discussed. Experimental results will be presented showing decreased light reflection from Si solar cells covered with ZnO nanowire arrays. #12;1. Introduction Waveguides

  20. FMEA for Solar Cell Array DATE 23 Jan, 1969

    E-print Network

    Rathbun, Julie A.

    . Figur·e 1 shows the general configuration. The solar cells used in this array are blueTK:ld Dist. EASEP Std. FMEA for Solar Cell Array NO. EATM-45 i REV. NO. PAGE - OF DATE 23 Jan, 1969 #12;NO. REV. NO. FMEA for Solar Cell Array EATM-45 PAGE 1 OF 15 DATE 23 Jan. 1969 *1. 0 SUMMARY

  1. Plasmonic Nanostructure Design for Efficient Light Coupling into Solar Cells

    E-print Network

    Atwater, Harry

    Plasmonic Nanostructure Design for Efficient Light Coupling into Solar Cells Vivian E. Ferry, Luke sunlight into guided modes in thin film Si and GaAs plasmonic solar cells whose back interface is coated. These findings show promise for the design of ultrathin solar cells that exhibit enhanced absorption

  2. Dielectric nanostructures for broadband light trapping in organic solar cells

    E-print Network

    Fan, Shanhui

    Dielectric nanostructures for broadband light trapping in organic solar cells Aaswath Raman, Zongfu@stanford.edu Abstract: Organic bulk heterojunction solar cells are a promising candidate for low-cost next lying on top of the organic solar cell stack produce a 8-15% increase in photocurrent for a model

  3. Multi-Exciton Generation in Nanostructured Solar Cells

    E-print Network

    Multi-Exciton Generation in Nanostructured Solar Cells 1 G.T. Zimanyi UC Davis The energy is challenging, philosophically satisfying and fun #12;Multi-Exciton Generation in Nanostructured Solar Cells 2. Science: - GaAs: Alta Devices: 28% lab, 23.5% NREL verified - Organic solar cells: Sumitomo 10

  4. Small Molecule Solution-Processed Bulk Heterojunction Solar Cells

    E-print Network

    Candea, George

    in solution processed BHJ solar cells, which are made from a PCBM Squaraine DyeCyanine Dye Absorber MoleculesSmall Molecule Solution-Processed Bulk Heterojunction Solar Cells Arthur Aebersold Supervisors: J solar cell performance show a trend for better devices with an intemediate active layer thickness

  5. ZnO Nanotube Based Dye-Sensitized Solar Cells

    E-print Network

    ZnO Nanotube Based Dye-Sensitized Solar Cells Alex B. F. Martinson,, Jeffrey W. Elam, Joseph T templated by anodic aluminum oxide for use in dye-sensitized solar cells (DSSCs). Atomic layer deposition of the best dye- sensitized solar cells (DSSCs) is the product of a dye with moderate extinction

  6. Hierarchically structured photoelectrodes for dye-sensitized solar cells

    E-print Network

    Cao, Guozhong

    Hierarchically structured photoelectrodes for dye-sensitized solar cells Qifeng Zhang and Guozhong or one-dimensional assemblies. Introduction Dye-sensitized solar cells (DSCs) are a category-sensitized solar cells using hierarchically structured photoelectrodes that consist of spherical or one

  7. Space Radiation Effects in Advanced Solar Cell Materials and Devices

    Microsoft Academic Search

    R. J. Walters; G. P. Summers

    An investigation of the physical mechanisms governing the response of III-V based solar cells to particle irradiation is presented. The effect of particle irradiation on single and multijunction solar cells is studied through current vs. voltage, spectral response, and deep level transient spectroscopy measurements. The basic radiation response mechanisms are identified, and their effects on the solar cell electrical performance

  8. Indium phosphide solar cells for laser power beaming applications

    Microsoft Academic Search

    Raj K. Jain; Geoffrey A. Landis

    1992-01-01

    Lasers can be used to transmit power to photovoltaic cells. Solar cell efficiencies are enhanced significantly under monochromatic light, and therefore a laser beam of proper wavelength could be a very effective source of illumination for a solar array operating at very high efficiencies. This work reviews the modeling studies made on indium phosphide solar cells for such an application.

  9. Solar Cells in 2009 and Beyond Mike McGehee

    E-print Network

    McGehee, Michael

    ;Inorganic Thin Film Solar Cells CdTe CIGS (CuInGaSe2) amorphous Si · A thin film of semiconductor.1 um 0.05 um ~1000 um #12;CdTe Solar Cell with CdS window layer 14 Glass Superstrate TransparentSolar Cells in 2009 and Beyond Mike McGehee Materials Science and Engineering These slides

  10. MILESTONES TOWARD 50% EFFICIENT SOLAR CELL MODULES Allen Barnett1

    E-print Network

    Honsberg, Christiana

    unoccupied design space. Our approach is driven by proven quantitative models for the solar cell design-design of the optics, interconnects and solar cells. This architecture significantly increases the design spaceMILESTONES TOWARD 50% EFFICIENT SOLAR CELL MODULES Allen Barnett1 , Douglas Kirkpatrick2

  11. 50% EFFICIENT SOLAR CELL ARCHITECTURES AND DESIGNS Allen Barnett1

    E-print Network

    Honsberg, Christiana

    are integrating the optical design with the solar cell design, and have entered previously unoccupied design space50% EFFICIENT SOLAR CELL ARCHITECTURES AND DESIGNS Allen Barnett1 , Christiana Honsberg1 , Douglas ABSTRACT Very High Efficiency Solar Cells (VHESC) for portable applications [1] that operate at greater

  12. Fabrication of buried contact silicon solar cells using porous silicon

    Microsoft Academic Search

    P. Vitanov; E. Goranova; V. Stavrov; P. Ivanov; P. K. Singh

    2009-01-01

    We report the fabrication of buried contact solar cells using porous silicon as sacrificial layer to create well-defined channels (for buried contacts) in silicon. In this paper, the salient features of the technology have been presented. No detrimental effect was found in the performance of buried contact solar cell with partially filled contact area compared to the solar cells having

  13. Improved performance of solar cell based on porous silicon surfaces

    Microsoft Academic Search

    Asmiet Ramizy; Wisam J. Aziz; Z. Hassan; Khalid Omar; K. Ibrahim

    2011-01-01

    Porous silicon (PS) surfaces were fabricated by electrochemical etching for both sides of the Si wafer. The objective of the present study is to investigate the PS effect on performance of silicon solar cells. Moreover, enhancement of solar cell efficiency can be obtained by manipulating of the reflected mirrors, and the process is very promising for solar cells manufacturing due

  14. Flexible thermal cycle test equipment for concentrator solar cells

    DOEpatents

    Hebert, Peter H. (Glendale, CA); Brandt, Randolph J. (Palmdale, CA)

    2012-06-19

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

  15. Analytical determination of critical crack size in solar cells

    Microsoft Academic Search

    C. P. Chen

    1988-01-01

    Although solar cells usually have chips and cracks, no material specifications concerning the allowable crack size on solar cells are available for quality assurance and engineering design usage. Any material specifications that the cell manufacturers use were developed for cosmetic reasons that have no technical basis. Therefore, the Applied Solar Energy Corporation (ASEC) has sponsored a continuing program for the

  16. Business, market and intellectual property analysis of polymer solar cells

    Microsoft Academic Search

    Torben D. Nielsen; Craig Cruickshank; Søren Foged; Jesper Thorsen; Frederik C. Krebs

    2010-01-01

    The business potential of polymer solar cells is reviewed and the market opportunities analyzed on the basis of the currently reported and projected performance and manufacturing cost of polymer solar cells. Possible new market areas are identified and described. An overview of the present patent and intellectual property situation is also given and a patent map of polymer solar cells

  17. 50 micron - Silicon solar cell assembly and testing

    Microsoft Academic Search

    Hidekazu Hashimoto; Yasuhiro Aoki; Masakazu Iwakami; Hiroshi Nishiyama

    1986-01-01

    An ultrathin silicon solar cell developed recently is advantageous for the high power spacecraft. A solar panel assembly technique suitable for the ultrathin silicon cell has been developed and established. Two types of welding methods, the parallel gap welding method (PGW) and improved solar welding method (ISW), have been introduced to interconnect these cells into the form of arrays, and

  18. Solar cell panel crack detection using Particle Swarm Optimization algorithm

    Microsoft Academic Search

    Amir Hossein Aghamohammadi; Anton Satria Prabuwono; Shahnorbanun Sahran; Marzieh Mogharrebi

    2011-01-01

    A solar cell panel as an efficient power source for the production of electrical energy has long been considered. Any defect on the solar cell panel's surface will be lead to reduced production of power and loss in the yield. In this case, inspection of the solar cell panel is essential to be performed to obtain a product of high

  19. Screen printed processing of solar cells incorporating integral bypass diodes

    Microsoft Academic Search

    S. R. Wenham; M. C. Pitt; R. B. Godfrey; M. A. Green; E. Gauja

    1982-01-01

    The output of solar modules utilizing conventional solar cells suffers considerably when a single cell in a string is shaded, cracked, broken or even poorly graded resulting in mismatch losses in the module. Under such conditions, integral bypass diode (I.B.D.) solar cells alleviate the worst electrical mismatch conditions. This allows the module to maintain a relatively high power output while

  20. Assembly technology of GaAs solar cell

    Microsoft Academic Search

    H. Matsumoto; S. Yoshida; T. Oda; M. Okubo; Y. Okawa

    1989-01-01

    The parallel gap welding technique used on GaAs solar cells is described. To find the lowest thickness of solar cell that can be welded by this technique, welding experiments are carried out on GaAs solar cells with thicknesses ranging between 100 and 280 microns. Results of these tests are presented. Coupon modules of 4 cm by 4 cm and 2

  1. Silvaco ATLAS as a solar cell modeling tool

    Microsoft Academic Search

    S. Michael; A. D. Bates; M. S. Green

    2005-01-01

    This paper presents research efforts conducted at the Naval Postgraduate School in the development of an accurate, physically-based solar cell model using the general-purpose ATLAS device simulator by Silvaco International. Unlike solar cell models based on a combination of discrete electrical components, this novel model extracts the electrical characteristics of a solar cell based on virtual fabrication of its physical

  2. Nanocluster production for solar cell applications

    SciTech Connect

    Al Dosari, Haila M.; Ayesh, Ahmad I. [Department of Physics, United Arab Emirates University, P. O. Box 15551, Al Ain (United Arab Emirates)] [Department of Physics, United Arab Emirates University, P. O. Box 15551, Al Ain (United Arab Emirates)

    2013-08-07

    This research focuses on the fabrication and characterization of silver (Ag) and silicon (Si) nanoclusters that might be used for solar cell applications. Silver and silicon nanoclusters have been synthesized by means of dc magnetron sputtering and inert gas condensation inside an ultra-high vacuum compatible system. We have found that nanocluster size distributions can be tuned by various source parameters, such as the sputtering discharge power, flow rate of argon inert gas, and aggregation length. Quadrupole mass filter and transmission electron microscopy were used to evaluate the size distribution of Ag and Si nanoclusters. Ag nanoclusters with average size in the range of 3.6–8.3 nm were synthesized (herein size refers to the nanocluster diameter), whereas Si nanoclusters' average size was controlled to range between 2.9 and 7.4 nm by controlling the source parameters. This work illustrates the ability of controlling the Si and Ag nanoclusters' sizes by proper optimization of the operation conditions. By controlling nanoclusters' sizes, one can alter their surface properties to suit the need to enhance solar cell efficiency. Herein, Ag nanoclusters were deposited on commercial polycrystalline solar cells. Short circuit current (I{sub SC}), open circuit voltage (V{sub OC}), fill factor, and efficiency (?) were obtained under light source with an intensity of 30 mW/cm{sup 2}. A 22.7% enhancement in solar cell efficiency could be measured after deposition of Ag nanoclusters, which demonstrates that Ag nanoclusters generated in this work are useful to enhance solar cell efficiency.

  3. Piezoresistance and solar cell efficiency

    NASA Technical Reports Server (NTRS)

    Weizer, Victor G.

    1987-01-01

    Diffusion-induced stresses in silicon are shown to result in large localized changes in the minority-carrier mobility which in turn can have a significant effect on cell output. Evidence is given that both compressive and tensile stresses can be generated in either the emitter or the base region. Tensile stresses in the base appear to be much more effective in altering cell performance than do compressive stresses. While most stress-related effects appear to degrade cell efficiency, this is not always the case. Evidence is presented showing that arsenic-induced stresses can result in emitter characteristics comparable to those found in the MINP cell without requiring a high degree of surface passivation.

  4. Laser synthesized super-hydrophobic conducting carbon with broccoli-type morphology as a counter-electrode for dye sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Gokhale, Rohan; Agarkar, Shruti; Debgupta, Joyashish; Shinde, Deodatta; Lefez, Benoit; Banerjee, Abhik; Jog, Jyoti; More, Mahendra; Hannoyer, Beatrice; Ogale, Satishchandra

    2012-10-01

    A laser photochemical process is introduced to realize superhydrophobic conducting carbon coatings with broccoli-type hierarchical morphology for use as a metal-free counter electrode in a dye sensitized solar cell. The process involves pulsed excimer laser irradiation of a thin layer of liquid haloaromatic organic solvent o-dichlorobenzene (DCB). The coating reflects a carbon nanoparticle-self assembled and process-controlled morphology that yields solar to electric power conversion efficiency of 5.1% as opposed to 6.2% obtained with the conventional Pt-based electrode.A laser photochemical process is introduced to realize superhydrophobic conducting carbon coatings with broccoli-type hierarchical morphology for use as a metal-free counter electrode in a dye sensitized solar cell. The process involves pulsed excimer laser irradiation of a thin layer of liquid haloaromatic organic solvent o-dichlorobenzene (DCB). The coating reflects a carbon nanoparticle-self assembled and process-controlled morphology that yields solar to electric power conversion efficiency of 5.1% as opposed to 6.2% obtained with the conventional Pt-based electrode. Electronic supplementary information (ESI) available: Materials and equipment details, solar cell fabrication protocol, electrolyte spreading time measurement details, XPS spectra, electronic study, film adhesion test detailed analysis and field emission results. See DOI: 10.1039/c2nr32082g

  5. Experimental and simulation analysis of the dye sensitized solar cell\\/Cu(In,Ga)Se 2 solar cell tandem structure

    Microsoft Academic Search

    W. L. Wang; H. Lin; J. Zhang; X. Li; A. Yamada; M. Konagai; J. B. Li

    2010-01-01

    A novel tandem structure composed of dye sensitized solar cell (DSC) and CuInGaSe2 (CIGS) solar cell shows the potential to increase conversion efficiency by fully utilizing the sunlight. In our research, a tandem solar cell with a high open-circuit voltage of 1.15V and a conversion efficiency of 10.46%, which is both larger than that of DSC and CIGS solar cell

  6. AlGaAs top solar cell for mechanical attachment in a multi-junction tandem concentrator solar cell stack

    Microsoft Academic Search

    L. C. Dinetta; M. H. Hannon; J. B. McNeely; A. M. Barnett

    1991-01-01

    The AstroPower self-supporting, transparent AlGaAs top solar cell can be stacked upon any well-developed bottom solar cell for improved system performance. This is an approach to improve the performance and scale of space photovoltaic power systems. Mechanically stacked tandem solar cell concentrator systems based on the AlGaAs top concentrator solar cell can provide near term efficiencies of 36 percent (AMO,

  7. Solar cell development for the power extension package

    Microsoft Academic Search

    C. R. Baraona; J. L. Cioni

    1981-01-01

    The PEP is a 32 kilowatt flexible substrate, retrievable, solar array system for use on the Space Shuttle. Solar cell costs will be reduced by increasing cell area and simplifying cell and coverglass fabrication processes and specifications. The cost goal is to produce cells below $30 per watt. Two and ten ohm-cm silicon cells were investigated. In phase I of

  8. High performance porous silicon solar cell development

    SciTech Connect

    Vernon, S.M.; Kalkhoran, N.M.; Maruska, H.P.; Halverson, W.D. [Spire Corp., Bedford, MA (United States)

    1994-12-31

    The authors have fabricated Si solar cells from porous Si/bulk Si structures. Two cell types, having the junction within the porous Si or within the bulk Si, were studied. They have seen clear evidence of the photovoltaic effect in porous Si, although currents and voltages are low, due to spreading resistance problems. On a non-AR-coated bulk Si p-n junction solar cell, formation of a porous Si surface layer increases both internal- and external quantum efficiency (QE) by functioning both as a light-trapping antireflection coating and an effective minority-carrier mirror. Current-voltage (I-V) data indicate that the porous Si layer does not lead to an increase in dark current.

  9. Transparent electrode materials for solar cells

    NASA Astrophysics Data System (ADS)

    Meiss, Jan; Uhrich, Christian L.; Fehse, Karsten; Pfuetzner, Steffen; Riede, Moritz K.; Leo, Karl

    2008-04-01

    Alternatives for replacing the expensive ITO are explored and Poly(ethylene dioxythiophene):polystyrene sulfonate (PEDOT:PSS) is introduced as one possibility. We present the first small-molecule organic solar cells employing only PEDOT:PSS as transparent electrode. Solar cells on glass and on flexible plastic foil were prepared, using a p-doped hole transporting material, zinc phthalocyanine (ZnPc) and C60 as donor-acceptor heterojunction, and an exciton blocking layer. Different methods to structure the PEDOT:PSS electrodes were investigated and are presented. As proof of principle, non-optimized prototype cells with efficiencies of over 0.7% on glass and 0.9% on flexible plastic foil substrate were obtained.

  10. Prediction of solar cell performance in space

    SciTech Connect

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

    1982-09-01

    Predicting solar array performance with a high degree of accuracy is of critical importance to the success of space missions. This calculation is influenced by a large number of variables and parameters. Consequently, the accurate prediction becomes very difficult and safety margins must be assigned because of unknown factors relating to incomplete description of the behavior of the materials and components in the solar array. This paper discusses two factors which are important in such predictions. The first is a description of the gradual deterioration of the optical transmissivity of the coverglass and its adhesive layer, using data derived from the solar cell experiment on the Naval Research Laboratory NTS-2 satellite. The magnitude of this effect is shown through the interpretation of satellite data. The second factor is temperature enhanced radiation damage which was observed during radiation experiments at low dose rates on silicon solar cells. These experiments are being carried out at the NRL Cobalt 60 facility. The observed radiation damage is shown to be strongly dependent on the temperature of the silicon cells during irradiation. The magnitude of this effect is shown in its influence on the interpretation of satellite data.

  11. Hypervelocity Impact Studies on Solar Cell Modules

    NASA Technical Reports Server (NTRS)

    Brandhorst, Henry W., Jr.; Best, Stevie R.

    2001-01-01

    Space environmental effects have caused severe problems as satellites move toward increased power and operating voltage levels. The greatest unknown, however, is the effect of high velocity micrometeoroid impacts on high voltage arrays (>200V). Understanding such impact phenomena is necessary for the design of future reliable, high voltage solar arrays, especially for Space Solar Power applications. Therefore, the objective of this work was to study the effect of hypervelocity impacts on high voltage solar arrays. Initially, state of the art, 18% efficient GaAs solar cell strings were targeted. The maximum bias voltage on a two-cell string was -200 V while the adjacent string was held at -140 V relative to the plasma potential. A hollow cathode device provided the plasma. Soda lime glass particles 40-120 micrometers in diameter were accelerated in the Hypervelocity Impact Facility to velocities as high as 11.6 km/sec. Coordinates and velocity were obtained for each of the approximately 40 particle impact sites on each shot. Arcing did occur, and both discharging and recharging of arcs between the two strings was observed. The recharging phenomena appeared to stop at approximately 66V string differential. No arcing was observed at 400 V on concentrator cell modules for the Stretched Lens Array.

  12. Laser synthesized super-hydrophobic conducting carbon with broccoli-type morphology as a counter-electrode for dye sensitized solar cells.

    PubMed

    Gokhale, Rohan; Agarkar, Shruti; Debgupta, Joyashish; Shinde, Deodatta; Lefez, Benoit; Banerjee, Abhik; Jog, Jyoti; More, Mahendra; Hannoyer, Beatrice; Ogale, Satishchandra

    2012-11-01

    A laser photochemical process is introduced to realize superhydrophobic conducting carbon coatings with broccoli-type hierarchical morphology for use as a metal-free counter electrode in a dye sensitized solar cell. The process involves pulsed excimer laser irradiation of a thin layer of liquid haloaromatic organic solvent o-dichlorobenzene (DCB). The coating reflects a carbon nanoparticle-self assembled and process-controlled morphology that yields solar to electric power conversion efficiency of 5.1% as opposed to 6.2% obtained with the conventional Pt-based electrode. PMID:23034799

  13. Gallium Arsenide solar cell radiation damage experiment

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

  14. Monolithically interconnected GaAs solar cells: A new interconnection technology for high voltage solar cell output

    Microsoft Academic Search

    L. C. Dinetta; M. H. Hannon

    1995-01-01

    Photovoltaic linear concentrator arrays can benefit from high performance solar cell technologies being developed at AstroPower. Specifically, these are the integration of thin GaAs solar cell and epitaxial lateral overgrowth technologies with the application of monolithically interconnected solar cell (MISC) techniques. This MISC array has several advantages which make it ideal for space concentrator systems. These are high system voltage,

  15. Accelerated stress testing of terrestrial solar cells

    NASA Technical Reports Server (NTRS)

    Prince, J. L.; Lathrop, J. W.

    1979-01-01

    A program to investigate the reliability characteristics of unencapsulated low-cost terrestrial solar cells using accelerated stress testing is described. Reliability (or parametric degradation) factors appropriate to the cell technologies and use conditions were studied and a series of accelerated stress tests was synthesized. An electrical measurement procedure and a data analysis and management system was derived, and stress test fixturing and material flow procedures were set up after consideration was given to the number of cells to be stress tested and measured and the nature of the information to be obtained from the process. Selected results and conclusions are presented.

  16. Research on light capture of solar cell and its application

    NASA Astrophysics Data System (ADS)

    Li, Tianze; Hou, Luan; Jiang, Chuan; Ma, Lixiu

    2009-08-01

    First of all, the article represents the character of photovoltaic effect and solar energy of semiconductor devices and the current situation of solar panel. It analyzes two difficuitys of the appplication of solar energy, the ways of enhancing solar cell performance and the barriers of producing high-efficiency PV modules. Solar photovoltaic technology, the technology use of solar energy and industry development trend are preticted.

  17. Luminescent solar concentrators and all-inorganic nanoparticle solar cells for solar energy harvesting

    NASA Astrophysics Data System (ADS)

    Sholin, Veronica

    Increasing energy demand and the parallel increase of greenhouse gas emissions are challenging researchers to find new and cleaner energy sources. Solar energy harvesting is arguably the most promising candidate for replacing fossil-fuel power generation. Photovoltaics are the most direct way of collecting solar energy; cost continues to hinder large-scale implementation of photovoltaics, however. Therefore, alternative technologies that will allow the extraction of solar power, while maintaining the overall costs of fabrication, installation, collection, and distribution low, must be explored. This thesis focuses on the fabrication and testing of two types of devices that step up to this challenge: the luminescent solar concentrator (LSC) and all-inorganic nanoparticle solar cells. In these devices I make use of novel materials, semiconducting polymers and inorganic nanoparticles, both of which have lower costs than the crystalline materials used in the fabrication of traditional photovoltaics. Furthermore, the cost of manufacturing LSCs and the nanoparticle solar cells is lower than the manufacturing cost of traditional optics-based concentrators and crystalline solar cells. An LSC is essentially a slab of luminescent material that acts as a planar light pipe. The LSC absorbs incoming photons and channels fluoresced photons toward appropriately located solar cells, which perform the photovoltaic conversion. By covering large areas with relatively inexpensive fluorescing organic dyes or semiconducting polymers, the area of solar cell needed is greatly reduced. Because semiconducting polymers and quantum dots may have small absorption/emission band overlaps, tunable absorption, and longer lifetimes, they are good candidates for LSC fabrication, promising improvement with respect to laser dyes traditionally used to fabricate LSCs. Here the efficiency of LSCs consisting of liquid solutions of semiconducting polymers encased in glass was measured and compared to the efficiency of LSCs based on small molecule laser dyes and on quantum dots. Factors affecting the optical efficiency of the system such as the luminescing properties of the fluorophors were examined. The experimental results were compared to Monte-Carlo simulations. Our results suggest that commercially available quantum dots cannot serve as viable LSC dyes because of large absorption/emission band overlap and relatively low quantum yield. Materials such as Red F demonstrate that semi-conducting polymers with high quantum yield and small absorption/emission band overlap are good candidates for LSCs. Recently, a solar cell system based purely on CdSe and Cite nanoparticles as the absorbing materials was proposed ans it was suggested that its operational mechanism was that of polymer donor/acceptor systems. Here we present solar cells consisting of a sintered active bilayer of CdSe and PbSe nanoparticles in the structure ITO/CdSe/interlayer/PbSe/Al, where an interlayer of LiF or Al2O3 was found necessary to prevent low shunt resistance from suppressing the photovoltaic behavior. We fabricated unoptimized solar cells with a short-circuit current of 6 mA/cm2, an open-circuit voltage of 0.18 V, and a fill factor of 41%. External quantum efficiency spectra revealed that photons from the infrared portion of the spectrum were not collected, suggesting that the low bandgap PbSe film did not contribute to the photocurrent of the structure despite exhibiting photoconductivity. Other measurements, however, showed that the PbSe film was indeed necessary to produce a photovoltage and transport electrons. Through sintering, the nanoparticle films acquired bandgaps similar to those of the corresponding bulk materials and became more conductive. Because the PbSe films were found to be considerably more conductive than the CdSe ones, we suggest that the PbSe layer is effectively behaving like a low conductivity electrical contact. Therefore, in contrast to the photovoltaics presented in the seminal research on CdSe/Cite solar cells, the CdSe/PbSe solar cell system presented here d

  18. Silicon solar cell process development, fabrication, and analysis

    NASA Technical Reports Server (NTRS)

    Yoo, H. I.; Iles, P. A.; Leung, D. C.

    1980-01-01

    Solar cells from HEM, Dendritic Webs, and EFG ribbons were fabricated and characterized. The HEM solar cells showed only slight enhancement in cell performance after gettering steps (diffusion glass) were added. Dendritic webs from various growth runs indicated that performance of solar cells made from the webs was not as good as that of the conventional CZ cells. The EFG ribbons grown in CO ambient showed significant improvement in silicon quality.

  19. Characterization of Low Temperature Deposited Flexible Amorphous Silicon Solar Cells

    Microsoft Academic Search

    Yingge Li; Dongxing Du

    2009-01-01

    N-i-p structure amorphous silicon solar cells deposited on flexible and glass substrates are successfully fabricated at low substrate temperature of 100°C through plasma enhanced chemical vapor deposition (PECVD) system. The external parameters of solar cells are characterized by solar simulator. The results indicate the best dot of the solar cells with glass substrate can reach to 5.54% of conversion efficiency

  20. A dye-sensitized solar cell driven electrochromic device

    Microsoft Academic Search

    Henriette Santa-Nokki; Jani Kallioinen; Jouko Korppi-Tommola

    2007-01-01

    A new dye-sensitized solar cell driven electrochromic device has been fabricated. The device consists of an electrochromic display and a solar cell in a single nanocrystalline film. The optimization of the electrochromic and the solar cell functions was carried out. An applied potential of 1.0 V was required for coloring and the best solar energy conversion efficiency 1.1% was achieved.

  1. Design, fabrication, characterization and improvement of Ge:Si solar cell below Si solar cell in a multi-junction solar cell system

    Microsoft Academic Search

    Yi Wang; Christopher Kerestes; Lu Wang; Andrew Gerger; Anthony Lochtefeld; Robert Opila; Allen Barnett

    2011-01-01

    Low band gap germanium:silicon (Ge:Si) solar cells for operation with a silicon solar cell in a multi-junction concentrator system was designed, fabricated, characterized and analyzed. First principle simulations show that an efficiency of 2.3% can be achieved for 88% Ge concentration Ge:Si solar cells below Si at 30 suns. Through solving critical shunting and open circuit voltage (Voc) problems, an

  2. Highly efficient light management for perovskite solar cells

    E-print Network

    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.

  3. Recent advances in sensitized mesoscopic solar cells.

    PubMed

    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-intensive high vacuum and materials purification steps that are currently employed in the fabrication of all other thin-film solar cells. Organic materials are abundantly available, so that the technology can be scaled up to the terawatt scale without running into feedstock supply problems. This gives organic-based solar cells an advantage over the two major competing thin-film photovoltaic devices, i.e., CdTe and CuIn(As)Se, which use highly toxic materials of low natural abundance. However, a drawback of the current embodiment of OPV cells is that their efficiency is significantly lower than that for single and multicrystalline silicon as well as CdTe and CuIn(As)Se cells. Also, polymer-based OPV cells are very sensitive to water and oxygen and, hence, need to be carefully sealed to avoid rapid degradation. The research discussed within the framework of this Account aims at identifying and providing solutions to the efficiency problems that the OPV field is still facing. The discussion focuses on mesoscopic solar cells, in particular, dye-sensitized solar cells (DSCs), which have been developed in our laboratory and remain the focus of our investigations. The efficiency problem is being tackled using molecular science and nanotechnology. The sensitizer constitutes the heart of the DSC, using sunlight to pump electrons from a lower to a higher energy level, generating in this fashion an electric potential difference, which can exploited to produce electric work. Currently, there is a quest for sensitizers that achieve effective harnessing of the red and near-IR part of sunlight, converting these photons to electricity better than the currently used generation of dyes. Progress in this area has been significant over the past few years, resulting in a boost in the conversion efficiency of the DSC that will be reviewed. PMID:19715294

  4. Accelerated stress testing of terrestrial solar cells

    NASA Technical Reports Server (NTRS)

    Lathrop, J. W.; Hawkins, D. C.; Prince, J. L.; Walker, H. A.

    1982-01-01

    The development of an accelerated test schedule for terrestrial solar cells is described. This schedule, based on anticipated failure modes deduced from a consideration of IC failure mechanisms, involves bias-temperature testing, humidity testing (including both 85-85 and pressure cooker stress), and thermal-cycle thermal-shock testing. Results are described for 12 different unencapsulated cell types. Both gradual electrical degradation and sudden catastrophic mechanical change were observed. These effects can be used to discriminate between cell types and technologies relative to their reliability attributes. Consideration is given to identifying laboratory failure modes which might lead to severe degradation in the field through second quadrant operation. Test results indicate that the ability of most cell types to withstand accelerated stress testing depends more on the manufacturer's design, processing, and worksmanship than on the particular metallization system. Preliminary tests comparing accelerated test results on encapsulated and unencapsulated cells are described.

  5. Gallium arsenide solar cell radiation damage study

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

    A thorough analysis has been made of electron- and proton- damaged GaAs solar cells suitable for use in space. It is found that, although some electrical parametric data and spectral response data are quite similar, the type of damage due to the two types of radiation is different. An I-V analysis model shows that electrons damage the bulk of the cell and its currents relatively more, while protons damage the junction of the cell and its voltages more. It is suggested that multiple defects due to protons in a strong field region such as a p/n junction cause the greater degradation in cell voltage, whereas the individual point defects in the quasi-neutral minority-carrier-diffusion regions due to electrons cause the greater degradation in cell current and spectral response.

  6. Assembly and characterization of quantum-dot solar cells

    Microsoft Academic Search

    Kurtis Siegfried Leschkies

    2009-01-01

    Environmentally clean renewable energy resources such as solar energy have gained significant attention due to a continual increase in worldwide energy demand. A variety of technologies have been developed to harness solar energy. For example, photovoltaic (or solar) cells based on silicon wafers can convert solar energy directly into electricity with high efficiency, however they are expensive to manufacture, and

  7. New high-efficiency silicon solar cells

    NASA Technical Reports Server (NTRS)

    Daud, T.; Crotty, G. T.

    1985-01-01

    A design for silicon solar cells was investigated as an approach to increasing the cell open-circuit voltage and efficiency for flat-plate terrestrial photovoltaic applications. This deviates from past designs, where either the entire front surface of the cell is covered by a planar junction or the surface is textured before junction formation, which results in an even greater (up to 70%) junction area. The heavily doped front region and the junction space charge region are potential areas of high recombination for generated and injected minority carriers. The design presented reduces junction area by spreading equidiameter dot junctions across the surface of the cell, spaced about a diffusion length or less from each other. Various dot diameters and spacings allowed variations in total junction area. A simplified analysis was done to obtain a first-order design optimization. Efficiencies of up to 19% can be obtained. Cell fabrication involved extra masking steps for selective junction diffusion, and made surface passivation a key element in obtaining good collection. It also involved photolithography, with line widths down to microns. A method is demonstrated for achieving potentially high open-circuit voltages and solar-cell efficiencies.

  8. Photochemical Energy Conversion.

    ERIC Educational Resources Information Center

    Batschelet, William H.; George, Arnold

    1986-01-01

    Describes procedures for two demonstrations: (1) photochemical energy conversion using ferric oxalate actinometry and (2) liquification of gases using Freon 114. Safety precautions are given for both demonstrations, as are procedures and material specifications. (JM)

  9. A high intensity solar cell invention: The edge-illuminated vertical multi-junction (VNJ) solar cell. Final report

    Microsoft Academic Search

    Sater

    1992-01-01

    This report contains a summary of a High Intensity Solar Cell (HI Cell) development carried out under the NIST\\/DOE Energy-Related Invention Program. The HI Cell, or Edge-Illuminated vertical Multi-junction Solar Cell, eliminates most major problems encountered with other concentrator solar cell designs. Its high voltage and low series resistance features make it ideally suited for efficient operation at high intensities.

  10. A high intensity solar cell invention: The edge-illuminated Vertical Multi-Junction (VMJ) solar cell

    Microsoft Academic Search

    Bernard L. Sater

    1992-01-01

    A summary is presented of a High Intensity Solar Cell (HI Cell) development carried out under the NIST\\/DOE Energy-Related Invention Program. The HI Cell, or Edge-Illuminated Vertical Multi-junction Solar Cell, eliminates most major problems encountered with other concentrator solar cell designs. Its high voltage and low series resistance features make it ideally suited for efficient operation at high intensities. Computer

  11. Low cost thin film chalcopyrite solar cells

    NASA Astrophysics Data System (ADS)

    Kapur, Vijay K.; Basol, Bulent M.; Tseng, Eric S.

    A new low-cost process for the production of thin-film chalcopyrite solar cells of the type CuInSe2/Cds is reported. The CuInSe2 films were prepared utilizing electroplating techniques, and solar cells with 1.0-sq cm area and over 7 percent efficiency (without the antireflection coating) were fabricated. Correcting for the shading and the reflection losses, these devices can be projected to be about 10.0 percent efficient. Electroplating methods were also used for the preparation of absorber materials of varying compositions, such as CuIn(1-x)Ga(x)Se2. These materials are being investigated to achieve bandgap values approaching 1.5 eV.

  12. Nanostructured upconverters for improved solar cell performance

    NASA Astrophysics Data System (ADS)

    MacQueen, Rowan W.; Schulze, Tim F.; Khoury, Tony; Cheng, Yuen Yap; Stannowski, Bernd; Lips, Klaus; Crossley, Maxwel J.; Schmidt, Timothy

    2013-09-01

    Triplet-triplet annihilation photon upconversion (TTA-UC) is a promising candidate for mitigating sub-band gap absorption losses in solar cells. In TTA-UC, sensitiser dyes absorb sub-band gap photons, cross to a triplet state, and transfer triplet excitons to emitter dyes. Two triplet-excited emitters can undergo TTA, raising one emitter to a higher-energy bright singlet state. The quadratic efficiency of TTA-UC at device-relevant light intensities motivates a push towards the higher chromophore densities achievable in the solid phase. We have begun this process by tethering tetrakisquinoxalino palladium porphyrin to 20nm silica nanoparticles using peptide chemistry techniques, achieving a total-volume concentration of 1.5mM. The phosphorescence kinetics of the tethered porphyrins was measured to quantify quenching by rubrene emitter. Upconverter performance was measured in a solar cell enhancement experiment.

  13. Thin-film polycrystalline silicon solar cells

    NASA Astrophysics Data System (ADS)

    Funghnan, B. W.; Blanc, J.; Phillips, W.; Redfield, D.

    1980-08-01

    Thirty-four new solar cells were fabricated on Wacker Sislo substrates and the AM-1 parameters were measured. A detailed comparison was made between the measurement of minority carrier diffusion length by the OE method and the penetrating light laser scan grain boundary photoresponse linewidth method. The laser scan method has more experimental uncertainty and agrees within 10 to 50% with the QE method. It allows determination of L over a large area. Atomic hydrogen passivation studies continued on Wacker material by three techniques. A method of determining surface recombination velocity, s, from laser scan data was developed. No change in s in completed solar cells after H-plasma treatment was observed within experimental error. H-passivation of bare silicon cars as measured by the new laser scan photoconductivity technique showed very large effects.

  14. An efficient power electronics solution for lateral multi-junction solar cell systems

    Microsoft Academic Search

    Mohammed Khorshed Alam; Faisal H. Khan; Abu Saleh Imtiaz

    2011-01-01

    Compared to a single junction solar cell, a multi-junction (MJ) solar cell can extract higher energy from sun by splitting the solar spectrum. Depending on the spectrum splitting techniques, two different structures of MJ solar cells are possible: vertical multijunction solar cell (VMJ) and lateral multijunction solar cell (LMJ). Both of these structures have their own advantages and limitations. LMJ

  15. Development of standardized specifications for silicon solar cells

    Microsoft Academic Search

    J. A. Scott-Monck

    1977-01-01

    A space silicon solar cell assembly (cell and coverglass) specification aimed at standardizing the diverse requirements of current cell or assembly specifications was developed. This specification was designed to minimize both the procurement and manufacturing costs for space qualified silicon solar cell assembilies. In addition, an impact analysis estimating the technological and economic effects of employing a standardized space silicon

  16. Development of a large area space solar cell assembly

    Microsoft Academic Search

    M. B. Spitzer

    1982-01-01

    The development of a large area high efficiency solar cell assembly is described. The assembly consists of an ion implanted silicon solar cell and glass cover. The important attributes of fabrication are the use of a back surface field which is compatible with a back surface reflector, and integration of coverglass application and cell fabrications. Cell development experiments concerned optimization

  17. The control of radiation resistance in space solar cells

    Microsoft Academic Search

    ARTHUR F. W. WILLOUGHBY

    1994-01-01

    Solar cells, powering satellites and other space vehicles, can suffer substantial degradation in performance by electron and proton irradiation experienced in orbit. These effects are first described, and the behaviour of silicon solar cells compared with cells of gallium arsenide and indium phosphide, and the more recent thin film type cells. In particular, the paper will discuss the phenomenon of

  18. CLEFT Process for GaAs Solar Cells

    NASA Technical Reports Server (NTRS)

    Fan, J. C. C.; Bozler, C. O.; Mcclelland, R. W.

    1983-01-01

    CLEFT (cleavage of lateral epitaxial films for transfer) process involves growing ultrathin gallium arsenide (GaAs solar cell on much thicker layer of same material). Growth method is completed solar cell easily separated by cleaving from much thicker substrate. Thick substrate is reusable in making additional cells, which reduces cell material cost.

  19. Triple junction polymer solar cells for photoelectrochemical water splitting.

    PubMed

    Esiner, Serkan; van Eersel, Harm; Wienk, Martijn M; Janssen, René A J

    2013-06-01

    A triple junction polymer solar cell in a novel 1 + 2 type configuration provides photoelectrochemical water splitting in its maximum power point at V ? 1.70 V with an estimated solar to hydrogen energy conversion efficiency of 3.1%. The triple junction cell consists of a wide bandgap front cell and two identical small bandgap middle and back cells. PMID:23625814

  20. Solar cells failure modes and improvement of reverse characteristics

    Microsoft Academic Search

    A. M. Ricaud

    1982-01-01

    Attention is given to the prevention of power loss-inducing 'hot spots' in large photovoltaic installations, at the levels of solar cell, array panel, and system design. Hot spots arise when one or several solar cells become back-biased and operate in the negative voltage quadrant, as a result of short circuit current mismatch, cell cracking, or cell shadowing. It is presently

  1. Organic Bulk-Heterojunction Solar Cells

    Microsoft Academic Search

    Carsten Deibel; Vladimir Dyakonov; Christoph J. Brabec

    2010-01-01

    Solar cells based on solution-processable organic semiconductors have\\u000a shown a considerable performance increase in recent years, and a lot of\\u000a progress has been made in the understanding of the elementary processes\\u000a of photogeneration. This review will first give a brief overview of the\\u000a historic development of plastic photovoltaics, and summarize the current\\u000a state of knowledge concerning the different steps from

  2. Organic p -i- n solar cells

    Microsoft Academic Search

    B. Maennig; J. Drechsel; D. Gebeyehu; P. Simon; F. Kozlowski; A. Werner; F. Li; S. Grundmann; S. Sonntag; M. Koch; K. Leo; M. Pfeiffer; H. Hoppe; D. Meissner; N. S. Sariciftci; I. Riedel; V. Dyakonov; J. Parisi

    2004-01-01

    We introduce a p-i- n-type heterojunction architecture for organic solar cells where the active region is sandwiched between two doped wide-gap layers. The term p-i- n means here a layer sequence in the form p-doped layer, intrinsic layer and n-doped layer. The doping is realized by controlled co-evaporation using organic dopants and leads to conductivities of 10 -4 to 10

  3. Thin monocrystalline silicon films for solar cells

    Microsoft Academic Search

    C. S. Solanki; R. R. Bilyalov; G. Beaucarne; J. Poortmans

    2003-01-01

    Thin film monocrystalline silicon solar cells based on porous silicon layer transfer processes could be cost-effective because of their lower consumption of material use and the potential for high efficiency. Novel techniques of porous silicon film separation, obtained by anodization of silicon, are presented. Anodization techniques for porous silicon film separation are classified as either one-step or two-step. Two-step anodization

  4. All screen printed dye solar cell

    Microsoft Academic Search

    Toby Meyer; David Martineau; Asef Azam; Andreas Meyer

    2007-01-01

    All screen printed Dye Sensitized Solar cell modules were fabricated and demonstrated excellent electrical performances thanks to a monolithic interconnection based on highly conductive carbon layers. Attained efficiency at 1000 W\\/m2 is 6 % with a fill-factor of 0.7. This monolithic module is very elegant to manufacture since the layers, including nano- TiO2 spacer, catalytic active layer, conductive carbon and

  5. Laser processing of silicon solar cells

    Microsoft Academic Search

    J. S. Katzeff; M. Lopez; D. R. Burger

    1981-01-01

    Results of a study to utilize an Nd:glass laser for production line annealing of ion implantation induced damage in solar cells are reported. Czochralski-grown and sawn Si wafers 7.6 cm in diam, 0.35 mm thick, were implanted with phosphorus junctions and boron BSFs. Annealing with electron beam, laser, and firing of an Al paste to form the BSFs in different

  6. Investigation of solar cell radiation damage

    Microsoft Academic Search

    J. Bernard; R. Reulet; R. A. Arndt

    1974-01-01

    A facility for studying the influence of space radiations on the lifetime of solar arrays is described, in which the test samples are made to move past electron, proton, and photon sources. Measurement of such parameters as current-voltage characteristic, minority-carrier diffusion length, and window transmission, are carried out in vacuum immediately after irradiation. Results obtained for silicon cells and CdS

  7. Machine vision for solar cell characterization

    Microsoft Academic Search

    Miguel A. Ordaz; Gregory B. Lush

    2000-01-01

    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)

  8. Inkjet Printing for Silicon Solar Cells

    Microsoft Academic Search

    Han-Chang Liu; Chia-Pin Chuang; Yi-Tsun Chen; Chen-Hsun Du

    2009-01-01

    Inkjet printing of metal nanoparticles is an attractive method for front-side metallization of silicon solar cells. It is\\u000a owing to noncontact, low-cost, low-waste, and simple process. In this work, we proposed the ink-jet printing and electroless\\u000a technology to fabricate the seed layer and electrode layer, respectively. Furthermore, we used electroplating method to increase\\u000a the electrode conductivity. In this way, the

  9. Thin film CdTe solar cells

    Microsoft Academic Search

    C. Cohen-Solal; M. Barbe; H. Afifi; G. Neu

    1985-01-01

    This paper reviews some of the most promising CdTe-based solar cells, with efficiencies in excess of 10 percent, prepared by various film deposition methods including close-spaced vapor transport, close-spaced sublimation, hot-wall vacuum evaporation, electrodeposition and screen-printing. One of the major problems with CdTe films has always been the difficulty of achieving high p-type doping in order to provide a low

  10. Microcrystalline organic thin-film solar cells.

    PubMed

    Verreet, Bregt; Heremans, Paul; Stesmans, Andre; Rand, Barry P

    2013-10-11

    Microcrystalline organic films with tunable thickness are produced directly on an indium-tin-oxide substrate, by crystallizing a thin amorphous rubrene film followed by its use as a template for subsequent homoepitaxial growth. These films, with exciton diffusion lengths exceeding 200 nm, produce solar cells with increasing photocurrents at thicknesses up to 400 nm with a fill factor >65%, demonstrating significant potential for microcrystalline organic electronic devices. PMID:23939936

  11. Large area plastic solar cell modules

    Microsoft Academic Search

    Frederik C. Krebs; Holger Spanggard; Torben Kjær; Matteo Biancardo; Jan Alstrup

    2007-01-01

    Preliminary data on the fabrication of 0.1m2 polymer solar cells are presented. The process employed screen-printing of an active layer onto an indium-tin-oxide (ITO) electrode pattern (50?square?1) on a 200?m polyethyleneterphthalate (PET) substrate. After the printing, vacuum coating of an optional layer of C60 and the final aluminium electrode was employed to complete the device. The active layer consisted of

  12. Semi-transparent inverted organic solar cells

    Microsoft Academic Search

    H. Schmidt; T. Winkler; M. Tilgner; H. Flügge; S. Schmale; T. Bülow; J. Meyer; H.-H. Johannes; T. Riedl; W. Kowalsky

    2009-01-01

    We will present efficient semi-transparent bulk-heterojunction [regioregular of poly(3-hexylthiophene): (6,6)-phenyl C61 butyric acid methyl ester] solar cells with an inverted device architecture. Highly transparent ZnO and TiO2 films prepared by Atomic Layer Deposition are used as cathode interlayers on top of ITO. The topanode consists of a RF-sputtered ITO layer. To avoid damage due to the plasma deposition of this

  13. Chalcopyrite thin film solar cells by electrodeposition

    Microsoft Academic Search

    D. Lincot; J. F. Guillemoles; S. Taunier; D. Guimard; J. Sicx-Kurdi; A. Chaumont; O. Roussel; O. Ramdani; C. Hubert; J. P. Fauvarque; N. Bodereau; L. Parissi; P. Panheleux; P. Fanouillere; N. Naghavi; P. P. Grand; M. Benfarah; P. Mogensen; O. Kerrec

    2004-01-01

    This paper reviews the state of the art in using electrodeposition to prepare chalcopyrite absorber layers in thin film solar cells. Most of the studies deal with the direct preparation of Cu(In,Ga)Se2 films, and show that the introduction of gallium in the films is now becoming possible from single bath containing all the elements. Electrodeposition can also be used to

  14. Solar-hydrogen fuel-cell vehicles

    Microsoft Academic Search

    Mark A. DeLuchi; Joan M. Ogden

    1993-01-01

    Hydrogen is an especially attractive transportation fuel. It is the least populating fuel available, and can be produced anywhere there is water and a clean source of electricity. A fuel cycle in which hydrogen is produced by solar-electrolysis of water, or by gasification of renewably grown biomass, and then used in a fuel-cell powered electric-motor vehicle (FCEV), would produce little

  15. Interfaces in thin film solar cells

    Microsoft Academic Search

    A. Klein; W. Jaegermann; R. Hunger; D. Kraft; F. Sauberlich; T. Schulmeyer; B. Spath

    2005-01-01

    Interfaces are important for the efficiencies of thin film solar cells. In particular, for polycrystalline chalcogenide semiconductors as CdTe and Cu(In,Ga)(S,Se)2 (CIGS) the existing physical concepts, which describe the electronic properties of elemental or III-V compound semiconductor interfaces quite well, are not sufficient. The increased complexity is mostly due to the non-abruptness of the interfaces and the strong tendency for

  16. High efficiency silicon solar cell review

    NASA Technical Reports Server (NTRS)

    Godlewski, M. P. (editor)

    1975-01-01

    An overview is presented of the current research and development efforts to improve the performance of the silicon solar cell. The 24 papers presented reviewed experimental and analytic modeling work which emphasizes the improvment of conversion efficiency and the reduction of manufacturing costs. A summary is given of the round-table discussion, in which the near- and far-term directions of future efficiency improvements were discussed.

  17. Shunt types in multicrystalline solar cells

    Microsoft Academic Search

    O. Breitenstein; J. P. Rakotoniaina; S. Neve; M. H. Al Rifai; M. Werner

    2003-01-01

    Nine different types of shunts have been found in state of the art multicrystalline solar cells by lock-in thermography and identified by SEM-investigation (incl. EBIC), TEM and EDX. These shunts differ by the type of their I-V characteristic (linear or non-linear) and by their physical origin. Six shunt types are process-induced, and three are caused by grown-in defects of the

  18. Controlled power interface between solar cells and AC source

    Microsoft Academic Search

    Koosuke Harada; Gen Zhao

    1993-01-01

    A novel interface circuit between solar cells and a commercial AC source using Van Allen's multivibrator is presented. In this circuit, the AC source is used as a backup for solar cells, and the source and load power flow is automatically balanced by the circuit itself without any external phase control. Based on the analysis of the characteristics of solar

  19. Dye Solar Cell Simulations Using Finite Element Method

    Microsoft Academic Search

    A. Gagliardi; M. Auf der Maur; A. Pecchia; A. Di Carlo

    2009-01-01

    Using solar power is one of the most important challenge of today technology. A big effort is devoted in going beyond traditional semiconductor, especially silicon based, solar cells. A well established and promising technology is represented by electrochemical dye solar cells (DSC). Their functioning is a complicated interplay of different parts deeply interconnected which requires a model able to catch

  20. Laser sintering of photoelectrode layers for Dye Solar Cell technology

    Microsoft Academic Search

    G. Mincuzzi; L. Vesce; R. Riccitelli; A. Reale; A. Di Carlo; T. M. Brown

    2009-01-01

    Scanning laser processing has become a useful and often used tool in thin film solar cell industries, since it enables precise, low cost, non-contact and highly automated fabrication processes such as scribing, patterning, marking, edge deletion, local melting and sintering. Dye solar cells (DSCs) are electrochemical photovoltaic devices representing an attractive technology for large area solar energy conversion since they

  1. Radial Electron Collection in Dye-Sensitized Solar Cells

    E-print Network

    Radial Electron Collection in Dye-Sensitized Solar Cells Alex B. F. Martinson,, Jeffrey W. Elam-sensitized solar cells (DSSCs). Atomic layer deposition is employed to grow indium tin oxide (ITO) within a porous-Northwestern Solar Energy Research Center, Northwestern UniVersity, 2145 Sheridan Road, EVanston, Illinois 60208

  2. Weak light effect in multicrystalline silicon solar cells

    Microsoft Academic Search

    He Wang; Hong Yang; Huacong Yu; Jianping Xi; Hongxun Hu; Guangde Chen

    2002-01-01

    Minority carrier trapping centers frequently exist in solar grade multicrystalline silicon, such trapping centers cause a drastic increase in photoconductance at carrier injection levels equal to and below the trap density, this phenomenon leads to higher open circuit voltage for multicrystalline silicon solar cells at illumination levels below about 0.2 suns compared to high performance crystalline silicon solar cells. In

  3. WORKING QUANTUM EFFICIENCY OF CDTE SOLAR CELL Zimeng Cheng

    E-print Network

    Chen 1 , Tao Zhou 2 , Qi Wang 3 , George E. Georgiou 1 , Ken K. Chin 1 1 Apollo CdTe Solar Energy Renewable Energy Laboratory (NREL), Golden, CO 80401 USA ABSTRACT For p-CdTe/n-CdS solar cell but also most importantly voltage dependent, since the CdTe solar cell is believed to be the diode which

  4. High efficiency InAlN-based solar cells

    Microsoft Academic Search

    R. E. Jones; R. Broesler; K. M. Yu; J. W. Ager; E. E. Haller; W. Walukiewicz; X. Chen; W. J. Schaff

    2008-01-01

    The band gap energies of the In1?xAlxN alloys are continuously tunable across the solar spectrum, making them good candidates for high efficiency solar cells. In particular, multijunction solar cells could be fabricated entirely from different compositions of this one alloy system. From modeling experimental measurements of the optical absorption coefficient in alloys with 0 ? × ? 0.6, a band

  5. AlGaAs top solar cell for mechanical attachment in a multi-junction tandem concentrator solar cell stack

    NASA Technical Reports Server (NTRS)

    Dinetta, L. C.; Hannon, M. H.; Mcneely, J. B.; Barnett, A. M.

    1991-01-01

    The AstroPower self-supporting, transparent AlGaAs top solar cell can be stacked upon any well-developed bottom solar cell for improved system performance. This is an approach to improve the performance and scale of space photovoltaic power systems. Mechanically stacked tandem solar cell concentrator systems based on the AlGaAs top concentrator solar cell can provide near term efficiencies of 36 percent (AMO, 100x). Possible tandem stack efficiencies greater than 38 percent (100x, AMO) are feasible with a careful selection of materials. In a three solar cell stack, system efficiencies exceed 41 percent (100x, AMO). These device results demonstrate a practical solution for a state-of-the-art top solar cell for attachment to an existing, well-developed solar cell.

  6. Measurement and Characterization of Concentrator Solar Cells II

    NASA Technical Reports Server (NTRS)

    Scheiman, Dave; Sater, Bernard L.; Chubb, Donald; Jenkins, Phillip; Snyder, Dave

    2005-01-01

    Concentrator solar cells are continuing to get more consideration for use in power systems. This interest is because concentrator systems can have a net lower cost per watt in solar cell materials plus ongoing improvements in sun-tracking technology. Quantitatively measuring the efficiency of solar cells under concentration is difficult. Traditionally, the light concentration on solar cells has been determined by using a ratio of the measured solar cell s short circuit current to that at one sun, this assumes that current changes proportionally with light intensity. This works well with low to moderate (<20 suns) concentration levels on "well-behaved" linear cells but does not apply when cells respond superlinearly, current increases faster than intensity, or sublinearly, current increases more slowly than intensity. This paper continues work on using view factors to determine the concentration level and linearity of the solar cell with mathematical view factor analysis and experimental results [1].

  7. Squaraine donor based organic solar cells

    NASA Astrophysics Data System (ADS)

    Wei, Guodan

    There are three main ongoing avenues to improve the power conversion efficiency of organic photovoltaics (OPV): the development of new organic materials, improved process control and novel device architecture design. In this thesis, through molecular design with chemical modification of functional organic molecules, a family of new highly absorptive solution processable squaraine (SQ) materials have been systematically synthesized and explored to improve the sunlight harvesting and charge transport. The spin-cast SQ donors are then coated with fullerene acceptors to form a unique nanocrystalline heterojunction (NcHJ) OPV device. This combination of a novel and efficient family of SQ donors, a unique NcHJ device architecture and optimized fabrication processes leads to high efficiency solar cells. For example, solar cells with efficiencies of ˜5.7 % and a fill factor ˜0.74 are achieved. We find a correlation between solar cell fill factor with the SQ thin film density, providing support for the molecular design concept that planar end groups result in close intermolecular stacking, and hence improved charge transport and exciton diffusion. Finally, thermal annealing of the films results in the formation of nanocrystalline morphologies that lead to further improvements in device performance. The microcrystal growth of SQ donors have been characterized by XRD, AFM and TEM.

  8. Modeling and analysis of multijunction solar cells

    NASA Astrophysics Data System (ADS)

    González, María; Chan, Ngai; Ekins-Daukes, Nicholas J.; Adams, Jessica G. J.; Stavrinou, Paul; Vurgaftman, Igor; Meyer, Jerry R.; Abell, Joshua; Walters, Robert J.; Cress, Cory D.; Jenkins, Phillip P.

    2011-02-01

    The modeling of high efficiency, multijunction (MJ) solar cells away from the radiative limit is presented. In the model, we quantify the effect of non-radiative recombination by using radiative efficiency as a figure of merit to extract realistic values of performance under different spectral conditions. This approach represents a deviation from the traditional detailed balance approximation, where losses in the device are assumed to occur purely through radiative recombination. For lattice matched multijunction solar cells, the model predicts efficiency values of 37.1% for AM0 conditions and 52.8% under AM1.5D at 1 sun and 500X, respectively. In addition to the theoretical study, we present an experimental approach to achieving these high efficiencies by implementing a lattice matched triple junction (TJ) solar cell grown on InP substrates. The projected efficiencies of this approach are compared to results for the state of the art inverted-metamorphic (IMM) technology. We account for the effect of metamorphic junctions, essential in IMM technology, by employing reduced radiative efficiencies as derived from recent data. We show that high efficiencies, comparable to current GaAs-based MJ technology, can be accomplished without any relaxed layers for growth on InP, and derive the optimum energy gaps, material alloys, and quantum-well structures necessary to realize them.

  9. PbSe nanocrystal excitonic solar cells.

    PubMed

    Choi, Joshua J; Lim, Yee-Fun; Santiago-Berrios, Mitk'el B; Oh, Matthew; Hyun, Byung-Ryool; Sun, Liangfeng; Bartnik, Adam C; Goedhart, Augusta; Malliaras, George G; Abruña, Héctor D; Wise, Frank W; Hanrath, Tobias

    2009-11-01

    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. PMID:19719095

  10. Dye-sensitized solar cell using novel tandem cell structure

    Microsoft Academic Search

    M. Murayama; T. Mori

    2007-01-01

    The authors report a new tandem cell structure for improving the short-circuit performance of a dye-sensitized solar cell. Two dye-sensitized nanocrystalline TiO2 films were placed face-to-face as electrodes. As a counter electrode, a platinum mesh sheet with transmittance was inserted between the electrodes. Two TiO2 anodes were connected in parallel with each other and in series with the Pt-mesh sheet

  11. Status of nonsilicon photovoltaic solar cell research

    NASA Astrophysics Data System (ADS)

    Deb, S. K.; Wallace, W. L.

    1980-01-01

    The current status of non-silicon photovoltaic solar cells is discussed, including the identification of current technical and economic issues and future research directions for potential high efficiency low cost technologies. This review covers such advanced materials as CdS/Cu2S, CdS/CuInSe2, and GaAs homojunction and heterojunction devices; such emerging materials as InP, Zn3P2 and CdTe; and liquid junction electrochemical photovoltaic cells. An attempt is made to compare the current relative status of these various technologies and to indicate their near term potential where possible.

  12. V-grooved silicon solar cells

    NASA Technical Reports Server (NTRS)

    Baraona, C. R.; Brandhorst, H. W., Jr.

    1975-01-01

    Silicon solar cells with macroscopic V-shaped grooves and microscopically texturized surfaces were made by preferential etching techniques. Various conditions for potassium hydroxide and hydrazine hydrate etching were investigated. Optical reflection losses from these surface were reduced. The reduced reflection occurred at all wavelengths and resulted in improved short circuit current and spectral response. Improved collection efficiency is also expected from this structure due to generation of carriers closer to the cell junction. Microscopic point measurements of collected current using a scanning electron microscope showed that current collected at the peaks of the texturized surface were only 80 percent of those collected in the valleys.

  13. Epitaxial solar-cell fabrication, phase 2

    NASA Technical Reports Server (NTRS)

    Daiello, R. V.; Robinson, P. H.; Kressel, H.

    1977-01-01

    Dichlorosilane (SiH2Cl2) was used as the silicon source material in all of the epitaxial growths. Both n/p/p(+) and p/n/n(+) structures were studied. Correlations were made between the measured profiles and the solar cell parameters, especially cell open-circuit voltage. It was found that in order to obtain consistently high open-circuit voltage, the epitaxial techniques used to grow the surface layer must be altered to obtain very abrupt doping profiles in the vicinity of the junction. With these techniques, it was possible to grow reproducibly both p/n/n(+) and n/p/p(+) solar cell structures having open-circuit voltages in the 610- to 630-mV range, with fill-factors in excess of 0.80 and AM-1 efficiencies of about 13%. Combinations and comparisons of epitaxial and diffused surface layers were also made. Using such surface layers, we found that the blue response of epitaxial cells could be improved, resulting in AM-1 short-circuit current densities of about 30 mA/cm sq. The best cells fabricated in this manner had AM-1 efficiency of 14.1%.

  14. Modeling of thin film solar cells - Uniform field approximation

    Microsoft Academic Search

    R. S. Crandall

    1983-01-01

    A model of a p-i-n thin-film solar cell is presented that can be easily used to analyze solar cell properties. The continuity equations are solved using the regional approximation, producing elementary solutions that give insight into the physics of the transport in the cell. The steady-state solutions are compared with measurements on typical hydrogenated amorphous silicon, a-Si:H, solar cells. The

  15. Novel methods of bonding solar cells

    NASA Astrophysics Data System (ADS)

    Thomaier, Rob

    2011-09-01

    Messy liquid adhesives, short work times, long cure times, difficult clean-up of stray adhesive - all of these are associated with liquid adhesives for bonding solar cells. Current adhesion methods have been in place since the '70s: mix a two-part liquid silicone adhesive, coat a portion of adhesive onto a section of substrate, place the cells in a vacuum bag and wait for the adhesive to cure. Alternatively, one can use a fairly complicated robotic procedure to apply adhesive then fix a cell down and, again, wait for the adhesive to cure. Some difficulties that need to be overcome include balancing the amount adhesive to spread out with the available worktime in order to get all the cells onto the substrate with good adhesion; controlling the bondline; ensuring that the adhesive cures correctly after application; and, finally, if there is any re-work, removing the part from the adhesive without damaging everything around it.

  16. Correcting For Capacitance In Tests Of Solar Cells

    NASA Technical Reports Server (NTRS)

    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.

  17. T and B Cell Immunity can be Reconstituted with Mismatched Hematopoietic Stem Cell Transplantation Without Alkylator Therapy in Artemis-Deficient Mice Using Anti-NK Antibody and Photochemically-Treated Sensitized Donor T Cells

    PubMed Central

    Xiao, Tony Z; Singh, Kanal; Dunn, Elizabeth; Ramachandran, Rageshree; Cowan, Morton J.

    2011-01-01

    Children with Artemis-deficient T-B-NK+ SCID (SCIDA) have very high risks of graft rejection from NK cells and toxicity from increased sensitivity to alkylating agents used for mismatched hematopoietic stem cell transplantation (HSCT). We evaluated the use of a non-alkylating agent regimen prior to HSCT in Artemis-deficient (mArt-/-) C57Bl/6 (B6) mice to open marrow niches and achieve long-term multilineage engraftment with full T and B cell immune reconstitution. We found that both partial depletion of recipient NK cells using anti-NK1.1 monoclonal antibody and donor T cells sensitized to recipient splenocytes were necessary. BALB/c sensitized T cells (STC) were photochemically -treated (PCT) with psoralen and UVA light to inhibit proliferation, reduce the risk of Graft-versus-host disease (GvHD) and target host hematopoietic stem cells (HSC). 4×105 PCT STC co-injected with 1×105 lineage-depleted c-kit+ BALB/c HSC resulted in 43.9±3.3% CD4+, 10.9±1.2% CD8+ donor T cells in blood; 29±7.8% and 21.7±4.0 donor B220+ IgM+ in spleen and bone marrow and 15.0±3.6% donor Gran-1+ cells in bone marrow at six months post transplant versus 0.02±0.0.01%, 0.13±0.10%, 0.53±0.16%, 0.49±0.09% and 0.20±0.06%, respectively, in controls that did not receive PCT STC. We found that STC target host HSC, and that PCT STC are detectable up to only 24 hours following infusion in contrast to non-photochemically treated STC which proliferate resulting in fatal GvHD. Increased mortality in the groups receiving 4-6×105 PCT-STC was associated with evidence of GvHD in particular the recipients of 6×105 cells. These results show that blocking NK cell mediated resistance and making niches in bone marrow are both essential to achieve multilineage engraftment of mismatched donor cells and T and B cell reconstitution although GvHD is not completely eliminated. PMID:22015994

  18. Defect behavior of polycrystalline solar cell silicon

    SciTech Connect

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

    1993-05-01

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

  19. MANUFACTURE OF PHOTOVOLTAIC SOLAR CELL USING PLANT CHLOROPHYLL

    EPA Science Inventory

    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...

  20. Transparent antennas for solar cell integration

    NASA Astrophysics Data System (ADS)

    Yasin, Tursunjan

    Transparent patch antennas are microstrip patch antennas that have a certain level of optical transparency. Highly transparent patch antennas are potentially suitable for integration with solar panels of small satellites, which are becoming increasingly important in space exploration. Traditional patch antennas employed on small satellites compete with solar cells for surface area. However, a transparent patch antenna can be placed directly on top of solar cells and resolve the issue of competing for limited surface real estate. For such an integration, a high optical transparency of the patch antenna is required from the solar cells' point of view. On the other hand, the antenna should possess at least acceptable radiation properties at the same time. This dissertation focuses on some of the most important concerns from the perspective of small satellite applications. For example, an optimization method to simultaneously improve both optical transparency and radiation efficiency of the antenna is studied. Active integrated antenna design method is extended to meshed patch applications in an attempt to improve the overall power efficiency of the front end communication subsystem. As is well known, circular polarization is immune from Faraday rotation effect in the ionosphere and thus can avoid a 3-dB loss in geo-satellite communication. Therefore, this research also aims to present design methods for circularly polarized meshed patch antennas. Moreover, a meshed patch antenna capable of supporting a high communication data rate is investigated. Lastly, other types of transparent patch antennas are also analyzed and compared to meshed patches. In summary, many properties of transparent patch antennas are examined in order to meet different design requirements.