Note: This page contains sample records for the topic photochemical solar cells from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: November 12, 2013.
1

Photochemical Deposition of Semiconductor Thin Films and Their Application for Solar Cells and Gas Sensors  

SciTech Connect

The photochemical deposition (PCD) technique was applied for solar cells and gas sensors. CdS and Cd{sub 1-x}Zn{sub x}S were deposited by PCD. Thiosulfate ions S{sub 2}O{sub 3}{sup 2-} act as a reductant and a sulfur source. The SnS absorption layer was deposited by three-step pulse electrochemical deposition. For the CdS/SnS structure, the best cell showed an efficiency of about 0.2%, while for the Cd{sub 1-x}Zn{sub x}S/SnS structure, an efficiency of up to 0.7% was obtained. For the gas sensor application, SnO{sub 2} was deposited by PCD from a solution containing SnSO{sub 4} and HNO{sub 3}. To enhance the sensitivity to hydrogen, Pd was doped by the photochemical doping method. The current increased by a factor of 10{sup 4} upon exposure to 5000 ppm hydrogen within 1 min at room temperature. 10{sup 3} times conductivity increase was observed even for 50 ppm hydrogen.

Ichimura, M.; Gunasekaran, M.; Sueyoshi, T. [Dept. Engineering Physics, Electronics and Mechanics, Nagoya Institute of Technology Gokiso, Showa, Nagoya 466-8555 (Japan)

2009-06-01

2

Photochemical Deposition of Semiconductor Thin Films and Their Application for Solar Cells and Gas Sensors  

NASA Astrophysics Data System (ADS)

The photochemical deposition (PCD) technique was applied for solar cells and gas sensors. CdS and Cd1-xZnxS were deposited by PCD. Thiosulfate ions S2O32- act as a reductant and a sulfur source. The SnS absorption layer was deposited by three-step pulse electrochemical deposition. For the CdS/SnS structure, the best cell showed an efficiency of about 0.2%, while for the Cd1-xZnxS/SnS structure, an efficiency of up to 0.7% was obtained. For the gas sensor application, SnO2 was deposited by PCD from a solution containing SnSO4 and HNO3. To enhance the sensitivity to hydrogen, Pd was doped by the photochemical doping method. The current increased by a factor of 104 upon exposure to 5000 ppm hydrogen within 1 min at room temperature. 103 times conductivity increase was observed even for 50 ppm hydrogen.

Ichimura, M.; Gunasekaran, M.; Sueyoshi, T.

2009-06-01

3

Photochemical conversion of solar energy.  

PubMed

Energy is the most important issue of the 21st century. About 85% of our energy comes from fossil fuels, a finite resource unevenly distributed beneath the Earth's surface. Reserves of fossil fuels are progressively decreasing, and their continued use produces harmful effects such as pollution that threatens human health and greenhouse gases associated with global warming. Prompt global action to solve the energy crisis is therefore needed. To pursue such an action, we are urged to save energy and to use energy in more efficient ways, but we are also forced to find alternative energy sources, the most convenient of which is solar energy for several reasons. The sun continuously provides the Earth with a huge amount of energy, fairly distributed all over the world. Its enormous potential as a clean, abundant, and economical energy source, however, cannot be exploited unless it is converted into useful forms of energy. This Review starts with a brief description of the mechanism at the basis of the natural photosynthesis and, then, reports the results obtained so far in the field of photochemical conversion of solar energy. The "grand challenge" for chemists is to find a convenient means for artificial conversion of solar energy into fuels. If chemists succeed to create an artificial photosynthetic process, "... life and civilization will continue as long as the sun shines!", as the Italian scientist Giacomo Ciamician forecast almost one hundred years ago. PMID:18605661

Balzani, Vincenzo; Credi, Alberto; Venturi, Margherita

2008-01-01

4

Photochemical Conversion of Solar Energy.  

National Technical Information Service (NTIS)

Totally illuminated-multi thin layer (TI-MTL) iron-thiazine photogalvanic cells with SnO2 anodes and InSnO2 cathodes were constructed. A .07% sunlight engineering efficiency for power conversion was obtained with a 4-element TI-MTL iron-thionine cell with...

N. N. Lichtin

1976-01-01

5

Photochemical Conversion of Solar Energy.  

National Technical Information Service (NTIS)

Totally-illuminated multi-thin-layer (TI-MTL) iron-thionine (Fe-TH+) photogalvanic cells have been constructed with SnO2 and InSnO2, respectively, as transparent anode and cathode. A .07% sunlight engineering efficiency was achieved with a 4-element cell ...

N. N. Lichtin

1975-01-01

6

Photochemical Conversion of Solar Energy.  

National Technical Information Service (NTIS)

Basic and applied aspects of thin-layer, totally-illuminated (TI-TL) iron-thiazine photogalvanic cells were investigated. I(sc) varies linearly with photostationary concentration of leucodye. Slopes indicate that I(sc) < 25% of the diffusion-controlled li...

N. D. Lichtin

1977-01-01

7

Chemically modified photochemical cell  

SciTech Connect

A chemically modified photoelectrochemical cell is disclosed including at least one cathode and a plurality of anodes, at least said plurality of anodes being constituted with a semiconductor, each of said plurality of anodes being formed by fixing through covalent bonds molecules of at least one sensitizer dye on the surface of a light-transmissible flat plate of an n-type semiconductor or a light-transmissible flat plate covered with a thin film of an n-type semiconductor, and said plurality of anodes being disposed parallelly to each other and in the form of layers in an electrolyte solution, together with said at least one cathode. Thus, since this photoelectrochemical cell can convert photoenergy of a longer wavelength to electric energy with a high efficiency by making the use of the dye sensitization effect, sufficient practical utility to the photodevices is obtained.

Osa, T.; Fujihira, M.

1983-09-06

8

Facile Photochemical Synthesis of Graphene-Pt Nanoparticle Composite for Counter Electrode in Dye Sensitized Solar Cell.  

PubMed

A low temperature route to synthesize graphene oxide-Pt nanoparticle hybrid composite by light assisted spontaneous coreduction of graphene oxide and chloroplatinic acid without reducing agent is demonstrated. Analysis indicates the importance of light as energy provider and ethanol as hole scavenger in the formation of small Pt nanoparticles (?3 nm) on graphene oxide as well as graphene oxide reduction. Spray coating was used to deposit the hybrid material as a counter electrode in dye sensitized solar cells (DSCs). An efficiency of 6.77% for the hybrid graphene counter electrode has been obtained, higher than the control device made by low temperature sputtered Pt as counter electrode. Compatibility of the hybrid material with flexible plastic substrates was demonstrated yielding DSCs of an efficiency of 4.05%. PMID:22646232

Tjoa, Verawati; Chua, Julianto; Pramana, Stevin S; Wei, Jun; Mhaisalkar, Subodh G; Mathews, Nripan

2012-06-19

9

Photochemical solar energy conversion. An assessment of scientific accomplishments  

Microsoft Academic Search

Research on photochemical solar energy conversion has grown exponentially. Basic sciences have benefited most from this research. The tenet of this article is that solar energy research has appreciably contributed to the ongoing renaissance of colloid chemistry and to the development of ever-more-sophisticated models for light-sensitized distance-controlled electron transfers. The need for compartmentalizing components of the photosynthetic apparatus-sensitizers: electron donors,

Janos H. Fendler

1985-01-01

10

Photochemical solar energy conversion. An assessment of scientific accomplishments  

SciTech Connect

Research on photochemical solar energy conversion has grown exponentially. Basic sciences have benefited most from this research. The tenet of this article is that solar energy research has appreciably contributed to the ongoing renaissance of colloid chemistry and to the development of ever-more-sophisticated models for light-sensitized distance-controlled electron transfers. The need for compartmentalizing components of the photosynthetic apparatus-sensitizers: electron donors, acceptors, and relays; and catalysts - has focused attention to microheterogeneous systems. Micelles, monolayers, organized multilayers, vesicles, polymerized vesicles, and dispersed colloidal semiconductors are used as molecular organizers in artifical photosynthesis. Properties and potentials of these systems have been summarized. Emphasis is placed on insights gained through photochemical investigations. Electron-transfer studies in covalently linked porphyrin-quinone, carotenoid polyene-porphyrin-quinone model compounds, and proteins are summarized.

Fendler, J.H.

1985-01-01

11

Solar cells  

Microsoft Academic Search

Solar cells are based on the photovoltaic effect of converting solar energy into electric energy. The mechanism for solar cells is divided into steps, that is, electron-hole pair generation by absorption of light in semiconductors, separation of electron-hole pairs by built-in potential, electron-hole recombination, collection of charge carriers by metal electrodes, etc. In this article, the principle and the theories

Hiroshi Tsubomura; Hikaru Kobayashi

1993-01-01

12

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

Microsoft Academic Search

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

B. Dellinger; J. L. Graham; J. M. Berman; P. H. Taylor

1994-01-01

13

Cell adhesion properties on photochemically functionalized diamond.  

PubMed

The biocompatibility of diamond was investigated with a view toward correlating surface chemistry and topography with cellular adhesion and growth. The adhesion properties of normal human dermal fibroblast (NHDF) cells on microcrystalline and ultrananocrystalline diamond (UNCD) surfaces were measured using atomic force microscopy. Cell adhesion forces increased by several times on the hydrogenated diamond surfaces after UV irradiation of the surfaces in air or after functionalization with undecylenic acid. A direct correlation between initial cell adhesion forces and the subsequent cell growth was observed. Cell adhesion forces were observed to be strongest on UV-treated UNCD, and cell growth experiments showed that UNCD was intrinsically more biocompatible than microcrystalline diamond surfaces. The surface carboxylic acid groups on the functionalized diamond surface provide tethering sites for laminin to support the growth of neuron cells. Finally, using capillary injection, a surface gradient of polyethylene glycol could be assembled on top of the diamond surface for the construction of a cell gradient. PMID:17407337

Chong, Kwok Feng; Loh, Kian Ping; Vedula, S R K; Lim, Chwee Teck; Sternschulte, Hadwig; Steinmüller, Doris; Sheu, Fwu-Shan; Zhong, Yu Lin

2007-04-04

14

Solar Cells and Solar Panels.  

National Technical Information Service (NTIS)

The bibliography is a selection of unclassified and unlimited distribution references on Solar Cells and Solar Panels. These citations of reports present information on performance characteristics, fabrication, development of power levels, degradation stu...

1973-01-01

15

Continuous flow photochemical reactor for solar decontamination of water using immobilized TiO 2  

Microsoft Academic Search

A photochemical reactor is designed for solar decontamination of organic pollutants in water, where the nanocrystalline photocatalyst TiO2 is immobilized on glass. The reactor modules could be connected in series and\\/or parallel to achieve desired flow rates under different conditions of illumination and degree of contamination. Methyl violet and phenol was found to completely degrade under solor irradiation and flow

G. R. R. A Kumara; F. M Sultanbawa; V. P. S Perera; I. R. M Kottegoda; K Tennakone

1999-01-01

16

Primary targets in photochemical inactivation of cells in culture  

NASA Astrophysics Data System (ADS)

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.

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

1995-01-01

17

Solar photochemical treatment of winery wastewater in a CPC reactor.  

PubMed

Degradation of simulated winery wastewater was studied in a pilot-scale compound parabolic collector (CPC) solar reactor. Total organic carbon (TOC) reduction by heterogeneous photocatalysis (TiO(2)) and homogeneous photocatalysis with photo-Fenton was observed. The influence of TiO(2) concentration (200 or 500 mg/L) and also of combining TiO(2) with H(2)O(2) or Na(2)S(2)O(8) on heterogeneous photocatalysis was evaluated. Heterogeneous photocatalysis with TiO(2), TiO(2)/H(2)O(2) and TiO(2)/S(2)O(8)(2-) is revealed to be inefficient in removing TOC, originating TOC degradation of 10%, 11% and 25%, respectively, at best. However, photo-Fenton experiments led to 46% TOC degradation in simulated wastewater prepared with diluted wine (WV) and 93% in wastewater prepared with diluted grape juice (WG), and if ethanol is previously eliminated from mixed wine and grape juice wastewater (WW) by air stripping, it removes 96% of TOC. Furthermore, toxicity decreases during the photo-Fenton reaction very significantly from 48% to 28%. At the same time, total polyphenols decrease 92%, improving wastewater biodegradability. PMID:19899762

Lucas, Marco S; Mosteo, Rosa; Maldonado, Manuel I; Malato, Sixto; Peres, José A

2009-12-01

18

Solar Cell Radiation Handbook.  

National Technical Information Service (NTIS)

The handbook to predict the degradation of solar cell electrical performance in any given space radiation environment is presented. Solar cell theory, cell manufacturing and how they are modeled mathematically are described. The interaction of energetic c...

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

1982-01-01

19

A simple framework for modelling the photochemical response to solar spectral irradiance variability in the stratosphere  

NASA Astrophysics Data System (ADS)

The stratosphere is thought to play a central role in the atmospheric response to solar irradiance variability. Recent observations suggest that the spectral solar irradiance (SSI) variability involves significant time-dependent spectral variations, with variable degrees of correlation between wavelengths, and new reconstructions are being developed. In this paper, we propose a simplified modelling framework to characterise the effect of short term SSI variability on stratospheric ozone. We focus on the pure photochemical effect, for it is the best constrained one. The photochemical effect is characterised using an ensemble simulation approach with multiple linear regression analysis. A photochemical column model is used with interactive photolysis for this purpose. Regression models and their coefficients provide a characterisation of the stratospheric ozone response to SSI variability and will allow future inter-comparisons between different SSI reconstructions. As a first step in this study, and to allow comparison with past studies, we take the representation of SSI variability from the Lean (1997) solar minimum and maximum spectra. First, solar maximum-minimum response is analysed for all chemical families and partitioning ratios, and is compared with past studies. The ozone response peaks at 0.18 ppmv (approximately 3%) at 37 km altitude. Second, ensemble simulations are regressed following two linear models. In the simplest case, an adjusted coefficient of determination R2 larger than 0.97 is found throughout the stratosphere using two predictors, namely the previous day's ozone perturbation and the current day's solar irradiance perturbation. A better accuracy (R2 larger than 0.9992) is achieved with an additional predictor, the previous day's solar irradiance perturbation. The regression models also provide simple parameterisations of the ozone perturbation due to SSI variability. Their skills as proxy models are evaluated independently against the photochemistry column model. The bias and RMS error of the best regression model are found smaller than 1% and 15% of the ozone response, respectively. Sensitivities to initial conditions and to magnitude of the SSI variability are also discussed.

Muncaster, R.; Bourqui, M. S.; Chabrillat, S.; Viscardy, S.; Melo, S. M. L.; Charbonneau, P.

2012-08-01

20

Solar Cell Radiation Handbook.  

National Technical Information Service (NTIS)

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...

J. R. Carter H. Y. Tada

1973-01-01

21

Flexible Solar Cells.  

National Technical Information Service (NTIS)

Solar cell 'modules' are plastic strips coated with thin films of photovoltaic silicon that collect solar energy for instant conversion into electricity. Lasers divide the thin film coating into smaller cells to build up voltage. Developed by Iowa Thin Fi...

1994-01-01

22

Solar Photovoltaic Cells.  

ERIC Educational Resources Information Center

|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…

Mickey, Charles D.

1981-01-01

23

Radiation damage in biomimetic dye molecules for solar cells  

Microsoft Academic Search

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

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

2009-01-01

24

Solar cell encapsulation  

SciTech Connect

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.

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

1983-05-10

25

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

Microsoft Academic Search

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

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

26

Nanocrystal solar cells  

Microsoft Academic Search

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

Ilan Gur; Ilan

2006-01-01

27

Solar Cells and Solar Panels. Volume I.  

National Technical Information Service (NTIS)

An annotated bibliography is provided of documents in which performance characteristics of various solar cells, particularly types containing gallium arsenides, silicon, or cadmium sulfides, are evaluated. Other reports include solar-cell fabrication, dev...

1970-01-01

28

Colloidal nanocrystal solar cells  

Microsoft Academic Search

.  Colloidal nanocrystal based organic solar cells are envisaged to be a cost effective alternative to conventional inorganic\\u000a cells. A variety of studies have been reported recently with the goal to increases energy conversion efficiencies, which must\\u000a be pushed towards 10% for devices to be practical. We review the status of this work, critically examining the factors affecting\\u000a hybrid solar cell

Sandeep Kumar; Gregory D. Scholes

2008-01-01

29

Dye Sensitized Solar Cells  

PubMed Central

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.

Wei, Di

2010-01-01

30

Solar cell power supply circuit  

SciTech Connect

A solar cell power supply circuit for use in a calculator or equipment is disclosed. It includes a solar cell or cells, a back-up capacitor connected to the solar cells, and a circuit element connected to be responsive whether the electromotive force from the solar cells lies within a range of operation for a load element of the solar cells, typically an LSI semiconductor device. The back-up capacitor starts charging when the electromotive force of the solar cells falls out of the range of operation for the load element. Preferably, an alarm sound is delivered when the electromotive force of the solar cells is poor.

Higuchi, M.

1984-02-28

31

Vertical Multijunction Solar Cells.  

National Technical Information Service (NTIS)

A theoretical analysis of the vertical multijunction (VMJ) solar cell was performed which indicated that using silicon certain configurations could be fabricated to satisfy the program objectives. Results indicate that initial AMO efficiencies of 15% can ...

P. M. Stella

1973-01-01

32

Solar cell array interconnects  

DOEpatents

Electrical interconnects are disclosed 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. 4 figs.

Carey, P.G.; Thompson, J.B.; Colella, N.J.; Williams, K.A.

1995-11-14

33

Silicon for Solar Cells.  

National Technical Information Service (NTIS)

This report is an introduction to silicon solar cell technology and photovoltaic device operation. The conventional semiconductor industry techniques for extraction of Si from quartz, purification of silanes, chemical vapor deposition of polycrystalline s...

T. F. Ciszek

1984-01-01

34

Thin silicon solar cells  

SciTech Connect

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.

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

35

Nanocrystal Solar Cells  

SciTech Connect

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.

Gur, Ilan

2006-12-15

36

Photoelectrochemical Solar Cells.  

ERIC Educational Resources Information Center

|This introduction to photoelectrochemical (PEC) cells reviews topics pertaining to solar energy conversion and demonstrates the ease with which a working PEC cell can be prepared with n-type silicon as the photoanode and a platinum counter electrode (both immersed in ethanolic ferrocene/ferricenium solutions). Experiments using the cell are…

McDevitt, John T.

1984-01-01

37

Parameterization of Solar Cells.  

National Technical Information Service (NTIS)

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 b...

J. Appelbaum A. Chait D. Thompson

1992-01-01

38

Integrated solar cell array  

Microsoft Academic Search

An integrated array of solar cells, each cell having a positive and a negative electrode, is disclosed. A first grid comprising a plurality of non-intersecting electrically conductive members is affixed to an insulating substrate. Each single individual member of this grid forms the negative electrode of an individual cell of the array. Overlying and affixed to the negative electrodes and

W. J. Biter; F. A. Shirland

1980-01-01

39

Sliver solar cells  

NASA Astrophysics Data System (ADS)

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

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

2007-12-01

40

Solar cell window fitting  

SciTech Connect

A window fitting is described comprising: (a) a frame structure dimensioned to fit in a window opening of a building; (b) a pair of transparent panes supported by the frame structure in substantially parallel disposition with respect to each other to define a space there between; a window blind secured to the frame structure so as to be disposed in the space between the transparent panes, the window blind comprising a plurality of slats mounted in generally parallel disposition with respect to each other for substantially simultaneous rotation of the slats so that each of the slats moves through an angular range from a CLOSED configuration in which the slats overlap each other so as to block passage of sunlight through the window opening to a fully OPEN configuration in which a maximum amount of sunlight can pass through the window opening; (d) a plurality of solar-chargeable batteries for storing electrical energy, the batteries being mounted on the slats; (e) a plurality of solar cells mounted on the batteries so as to be exposed to sunlight incident upon the slats, the batteries thereby being sandwiched between the solar cells and the slats, the solar cells being electrically connected to the batteries so that the batteries can be electrically charged by the solar cells; and means for removing from the batteries the stored electrical energy that has been generated by the solar cells.

Gillard, C.W.

1993-06-22

41

Large Retractable Solar Cell Array.  

National Technical Information Service (NTIS)

Presented are detailed drawings of the orientation mechanism in corporation of reference solar cell and solar cell modules of 8 and 12-mil cells in the solar panel design, detail drawings of the drum mechanism and solar array, and all electronic circuit d...

E. O. Felkel G. Wolff

1969-01-01

42

Terrestrial solar spectra, solar simulation and solar cell efficiency measurement  

NASA Astrophysics Data System (ADS)

Fundamentals of light transmittance and, both measured and modeled atmospheric effects (i.e., air mass, molecular and aerosal scattering, and absorption) on terrestrial solar spectra are discussed. Geometric effects, such as global rather than direct beam measurements, and detector orientation are also reviewed. The SERI proposed ASTM global and direct beam terrestrial solar spectra are also presented. A detailed review/evaluation of the spectral characteristics of a number of solar simulators is given. Methods of calibrating the short circuit current of a solar cell with respect to a given irradiance spectrum are discussed. In conclusion, the need for a sophisticated solar simulator is proportional to the spectral mismatch betwen the spectral response of the reference cell used to set the solar simulator and that of the test cell. The ASTM terrestrial solar irradiance spectrum is recommended as a reference, spectrum and, the used either filtered xenon arc or dichroic filtered tungsten halogen lamps for solar simulation is also recommended.

Matson, R.; Bird, R.; Emery, K.

1981-09-01

43

Parameterization of solar cells  

NASA Astrophysics Data System (ADS)

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.

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

1992-10-01

44

Thin film solar cells  

SciTech Connect

Written for graduate students and R and D scientists and engineers, this text provides a lucid treatment of many facets of materials, technologies, and solid-state physics of thin film solar cell devices. The various types of homo-, hetero-, barrier, and liquid junction solar cells involving amorphous, polycrystalline, and epitaxial semiconductor thin films are all covered. The volume details the basic solid-state physics of junction devices and describes thin film materials and associated preparation, measurement, and analysis techniques, as well as device technology. The authors present a critical comparative analysis of the performance of various types of thin film solar cells in order to focus on the present status of the field and to project future developments.

Chopra, K.L.; Das, S.R.

1983-01-01

45

Photochemical Inactivation of Cell-Associated Human Immunodeficiency Virus in Platelet Concentrates  

Microsoft Academic Search

Photochemical decontamination (PCD) of platelet concen- trates, with adequate preservation of platelet function, has been shown using 8-methoxypsoralen (8-MOP) and long wavelength UV light (UVA). To further evaluate this tech- nique, models for the inactivation of pathogenic human cell-associated viruses and integrated proviral sequences are required. We have assessed the ability of the PCD tech- nique to inactivate cell-associated human

Lily Lin; Helen Londe; Carl V. Hanson; Gary Wiesehahn; Stephen Isaacs; George Cirnino; Laurence Corash

46

Photochemical transformation of azoxystrobin in aqueous solutions  

Microsoft Academic Search

The photochemical behaviour of azoxystrobin fungicide (AZX) in water was studied under laboratory conditions. Photodegradation was initiated using a solar simulator (xenon arc lamp) or a jacketed Pyrex reaction cell equipped with a 125W, high-pressure mercury lamp. HPLC\\/MS analysis (APCI and ESI in positive and negative modes) was used to identify AZX photoproducts. The calculated polychromatic quantum efficiencies (?) of

A. Boudina; C. Emmelin; A. Baaliouamer; O. Païssé; J. M. Chovelon

2007-01-01

47

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

Microsoft Academic Search

Results and conclusions obtained during the investigation of amorphous silicon, 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

C. M. Fortmann; S. S. Hegedus

1992-01-01

48

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

PubMed Central

This study describes the photochemical deposition of Co-based oxygen evolution catalysts on a semiconductor photoanode for use in solar oxygen evolution. In the photodeposition process, electron-hole pairs are generated in a semiconductor upon illumination and the photogenerated holes are used to oxidize Co2+ ions to Co3+ ions, resulting in the precipitation of Co3+-based catalysts on the semiconductor surface. Both photodeposition of the catalyst and solar O2 evolution are photo-oxidation reactions using the photogenerated holes. Therefore, photodeposition provides an efficient way to couple oxygen evolution catalysts with photoanodes by naturally placing catalysts at the locations where the holes are most readily available for solar O2 evolution. In this study Co-based catalysts were photochemically deposited as 10–30 nm nanoparticles on the ZnO surface. The comparison of the photocurrent-voltage characteristics of the ZnO electrodes with and without the presence of the Co-based catalyst demonstrated that the catalyst generally enhanced the anodic photocurrent of the ZnO electrode with its effect more pronounced when the band bending is less significant. The presence of Co-based catalyst on the ZnO photoanode also shifted the onset potential of the photocurrent by 0.23 V to the negative direction, closer to the flat band potential. These results demonstrated that the cobalt-based catalyst can efficiently use the photogenerated holes in ZnO to enhance solar O2 evolution. The photodeposition method described in this study can be used as a general route to deposit the Co-based catalysts on any semiconductor electrode with a valence band edge located at a more positive potential than the oxidation potential of Co2+ ions.

Steinmiller, Ellen M. P.; Choi, Kyoung-Shin

2009-01-01

49

Solar PV- How A Solar Cell Works  

NSDL National Science Digital Library

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.

Levander, Alejandro

2011-03-03

50

Solar-cell panel simulator  

Microsoft Academic Search

The energy generated by solar cells can be transformed into ac power by means of inverters. In most cases these inverters cannot be tested under real conditions, since large solar-cell arrays are not yet available at reasonable prices. Therefore, a circuit that simulates a solar-cell array has been developed.

D. Baert

1979-01-01

51

Advanced solar cell concepts1  

Microsoft Academic Search

In order to ensure the widespread use of solar photovoltaic technology for terrestrial applications, cost per unit watt must be significantly lower than 1$\\/Watt level. Material limitation of wafer based Si cell technology and efficiency limitation of thin-film solar cell technologies needs to overcome in order to achieve the above- mentioned cost goal. Thermodynamically solar cell efficiencies can be as

C. S. Solanki; G. Beaucarne

2007-01-01

52

NASA Facts, Solar Cells.  

ERIC Educational Resources Information Center

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

National Aeronautics and Space Administration, Washington, DC.

53

Amorphous semiconductor solar cell  

DOEpatents

A solar cell comprising a back electrical contact, amorphous silicon semiconductor base and junction layers and a top electrical contact includes in its manufacture the step of heat treating the physical junction between the base layer and junction layer to diffuse the dopant species at the physical junction into the base layer.

Dalal, Vikram L. (Newark, DE)

1981-01-01

54

Polymer solar cells.  

PubMed

This article reviews the motivations for developing polymer-based photovoltaics and describes some of the material systems used. Current challenges are identified, and some recent developments in the field are outlined. In particular, recent work to image and control nanostructure in polymer-based solar cells is reviewed, and very recent progress is described using the unique properties of organic semiconductors to develop strategies that may allow the Shockley-Queisser limit to be broken in a simple photovoltaic cell. PMID:23816905

Greenham, Neil C

2013-07-01

55

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

PubMed Central

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.

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

2004-01-01

56

EDITORIAL: Nanostructured solar cells Nanostructured solar cells  

NASA Astrophysics Data System (ADS)

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

Greenham, Neil C.; Grätzel, Michael

2008-10-01

57

Large Retractable Solar Cell Array.  

National Technical Information Service (NTIS)

The main activities on the Large Retractable Solar Cell Array(LRSCA) program during the fifth quarterly reporting period consisted of completion of the detailed drawings of the solar array, drum mechanism, and control electronics unit (CEU). Circuit desig...

E. O. Felkel G. Wolff M. C. Olson W. N. Turner R. E. Daniel

1969-01-01

58

Silicon Solar Cell Turns 50  

SciTech Connect

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

Perlin, J.

2004-08-01

59

Solar energy conversion in a photoelectrochemical biofuel cell.  

PubMed

A photoelectrochemical biofuel cell has been developed which incorporates aspects of both an enzymatic biofuel cell and a dye-sensitized solar cell. Photon absorption at a porphyrin-sensitized n-type semiconductor electrode gives rise to a charge-separated state. Electrons and holes are shuttled to appropriate cathodic and anodic catalysts, respectively, allowing the production of electricity, or a reduced fuel, via the photochemical oxidation of a biomass-derived substrate. The operation of this device is reviewed. The use of alternate anodic redox mediators provides insight regarding loss mechanisms in the device. Design strategies for enhanced performance are discussed. PMID:19904423

Hambourger, Michael; Kodis, Gerdenis; Vaughn, Michael D; Moore, Gary F; Gust, Devens; Moore, Ana L; Moore, Thomas A

2009-10-15

60

Optical properties of tropospheric aerosols determined by lidar and spectrophotometric measurements (Photochemical Activity and Solar Ultraviolet Radiation campaign).  

PubMed

We present the results of the aerosol measurements carried out over the Aegean Sea during the Photochemical Activity and Solar Ultraviolet Radiation campaign held in Greece during June 1996. Simultaneous observations performed with a lidar and a double-monochromator spectrophotometer allowed us to retrieve the optical depth, the Angström coefficient, and the backscatter-to-extinction ratio. The Sun photometric data can be used to improve quantitative aerosol measurements by lidar in the Planetary Boundary Layer. Systematic errors could arise otherwise, because the value of the backscatter-to-extinction ratio has to be supplied. Instead this ratio can be retrieved experimentally by use of an iterative solution of the lidar equation. PMID:18259559

Marenco, F; Santacesaria, V; Bais, A F; Balis, D; di Sarra, A; Papayannis, A; Zerefos, C

1997-09-20

61

Photochemical internalisation of a macromolecular protein toxin using a cell penetrating peptide-photosensitiser conjugate.  

PubMed

Photochemical internalisation (PCI) is a site-specific technique for improving cellular delivery of macromolecular drugs. In this study, a cell penetrating peptide, containing the core HIV-1 Tat 48-57 sequence, conjugated with a porphyrin photosensitiser has been shown to be effective for PCI. Herein we report an investigation of the photophysical and photobiological properties of a water soluble bioconjugate of the cationic Tat peptide with a hydrophobic tetraphenylporphyrin derivative. The cellular uptake and localisation of the amphiphilic bioconjugate was examined in the HN5 human head and neck squamous cell carcinoma cell line. Efficient cellular uptake and localisation in endo/lysosomal vesicles was found using fluorescence detection, and light-induced, rupture of the vesicles resulting in a more diffuse intracellular fluorescence distribution was observed. Conjugation of the Tat sequence with a hydrophobic porphyrin thus enables cellular delivery of an amphiphilic photosensitiser which can then localise in endo/lysosomal membranes, as required for effective PCI treatment. PCI efficacy was tested in combination with a protein toxin, saporin, and a significant reduction in cell viability was measured versus saporin or photosensitiser treatment alone. This study demonstrates that the cell penetrating peptide-photosensitiser bioconjugation strategy is a promising and versatile approach for enhancing the therapeutic potential of bioactive agents through photochemical internalisation. PMID:21889554

Wang, Julie T-W; Giuntini, Francesca; Eggleston, Ian M; Bown, Stephen G; MacRobert, Alexander J

2011-08-25

62

Amorphous silicon solar cells  

NASA Astrophysics Data System (ADS)

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 (LAMBDA) (+1).cm(+1)) were produced in an rf discharge for T/sub s/ 4000 C and in a dc cathodic discharge for T/sub s/ 3500 C. Diffusion lengths of approx. 0.8 (SIGMA)m were measured in undoped a-Si:H films at illumination levels of approx. 0.1 Sun. The activation energy of the diffusion length is 0.28 eV. The technique for measuring the diffusion length was improved by a liquid Schottky-barrier contact. It is confirmed that carbon alloying of the p layer improves the performance of p-i-n cells illuminated through that layer and also that the stability is better for cells illuminated through the p layer. It is indicated that a major factor determining the efficiency of ITO/n-i-p cells is the ITC/n contact. Several parameters were determined that affect device stability. A gradual boron profile enhances stability, as does a thin, undoped layer. Increased oxygen contamination increases the degradation of a-Si:H p-i-n cells.

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

1981-05-01

63

Quantum junction solar cells.  

PubMed

Colloidal quantum dot solids combine convenient solution-processing with quantum size effect tuning, offering avenues to high-efficiency multijunction cells based on a single materials synthesis and processing platform. The highest-performing colloidal quantum dot rectifying devices reported to date have relied on a junction between a quantum-tuned absorber and a bulk material (e.g., TiO(2)); however, quantum tuning of the absorber then requires complete redesign of the bulk acceptor, compromising the benefits of facile quantum tuning. Here we report rectifying junctions constructed entirely using inherently band-aligned quantum-tuned materials. Realizing these quantum junction diodes relied upon the creation of an n-type quantum dot solid having a clean bandgap. We combine stable, chemically compatible, high-performance n-type and p-type materials to create the first quantum junction solar cells. We present a family of photovoltaic devices having widely tuned bandgaps of 0.6-1.6 eV that excel where conventional quantum-to-bulk devices fail to perform. Devices having optimal single-junction bandgaps exhibit certified AM1.5 solar power conversion efficiencies of 5.4%. Control over doping in quantum solids, and the successful integration of these materials to form stable quantum junctions, offers a powerful new degree of freedom to colloidal quantum dot optoelectronics. PMID:22881834

Tang, Jiang; Liu, Huan; Zhitomirsky, David; Hoogland, Sjoerd; Wang, Xihua; Furukawa, Melissa; Levina, Larissa; Sargent, Edward H

2012-08-16

64

Solar fuels  

NASA Astrophysics Data System (ADS)

The aim of this paper is to give a review concerning the storage of solar energy by converting it to chemical energy. This is based on several articles published during the last fifteen years. The methods to convert solar energy to chemical energy, e.g., to produce hydrogen, can be divided into three different methods. The most common one is probably the usage of solar cells; thus the solar energy is first converted into electrical energy and further the water is split electrochemically to produce hydrogen. It could be also done in a photoelectrochemical cell, or simply photochemically. A photobiological system can also be considered as a photochemical system, although it is discussed separately from the photochemical systems. These three last mentioned methods will be discussed in this paper.

Viitanen, M.

1990-12-01

65

An Introduction to Solar Cells  

ERIC Educational Resources Information Center

|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…

Feldman, Bernard J.

2010-01-01

66

Flexible solar cells for clothing  

Microsoft Academic Search

Integration of flexible solar cells into clothing can provide power for portable electronic devices. Photovoltaics is the most advanced way of providing electricity far from any mains supply, although it suffers from the limits of ambient light intensity. But the energy demand of portable devices is now low enough that clothing-integrated solar cells are able to power most mobile electronics.

Markus B. Schubert; Jürgen H. Werner

2006-01-01

67

Colloidal quantum dot solar cells  

NASA Astrophysics Data System (ADS)

Solar cells based on solution-processed semiconductor nanoparticles -- colloidal quantum dots -- have seen rapid advances in recent years. By offering full-spectrum solar harvesting, these cells are poised to address the urgent need for low-cost, high-efficiency photovoltaics.

Sargent, Edward H.

2012-03-01

68

Carbon Nanotube Solar Cells  

PubMed Central

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

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

2012-01-01

69

Lunar production of solar cells  

NASA Astrophysics Data System (ADS)

The feasibility of manufacturing of solar cells on the moon for spacecraft applications is examined. Because of the much lower escape velocity, there is a great advantage in lunar manufacture of solar cells compared to Earth manufacture. Silicon is abundant on the moon, and new refining methods allow it to be reduced and purified without extensive reliance on materials unavailable on the moon. Silicon and amorphous silicon solar cells could be manufactured on the moon for use in space. Concepts for the production of a baseline amorphous silicon cell are discussed, and specific power levels are calculated for cells designed for both lunar and Earth manufacture.

Landis, Geoffrey A.; Perino, Maria Antonietta

1989-05-01

70

Thin Film Solar Cell Workshop.  

National Technical Information Service (NTIS)

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...

J. Armstrong F. Jeffrey

1993-01-01

71

Role of Superoxide Dismutase in the Photochemical Response of Cultured RPE Cells to Laser Exposure at 413 nm.  

National Technical Information Service (NTIS)

Thresholds for photochemical damage were performed in RPE cell lines (artificially pigmented) taken from either human (hTERT-RPE1), wild type (wt) mouse, or transgenic mice deficient (+/-) in either superoxide dismutase 1 (SOD1) or SOD2. The four cell lin...

K. J. Schuster L. E. Estlack M. L. Denton M. S. Foltz R. J. Thomas

2007-01-01

72

Isomerization and Aggregation of the Solar Cell Dye D149.  

PubMed

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 ZrO(2), partially including a coadsorbent. In solution, excitation to the S(2) 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 ZrO(2). 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

El-Zohry, Ahmed; Orthaber, Andreas; Zietz, Burkhard

2012-11-26

73

Isomerization and Aggregation of the Solar Cell Dye D149  

PubMed Central

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.

2012-01-01

74

Upconversion in solar cells  

PubMed Central

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

2013-01-01

75

Germanium Nanocrystal Solar Cells  

NASA Astrophysics Data System (ADS)

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.

Holman, Zachary Charles

76

Multiple Exciton Generation Solar Cells  

SciTech Connect

Heat loss is the major factor limiting traditional single junction solar cells to a theoretical efficiency of 32%. Multiple Exciton Generation (MEG) enables efficient use of the solar spectrum yielding a theoretical power conversion efficiency of 44% in solar cells under 1-sun conditions. Quantum-confined semiconductors have demonstrated the ability to generate multiple carriers but present-day materials deliver efficiencies far below the SQ limit of 32%. Semiconductor quantum dots of PbSe and PbS provide an active testbed for developing high-efficiency, inexpensive solar cells benefitting from quantum confinement effects. Here, we will present recent work of solar cells employing MEG to yield external quantum efficiencies exceeding 100%.

Luther, J. M.; Semonin, O. E.; Beard, M. C.; Gao, J.; Nozik, A. J.

2012-01-01

77

Lithium counterdoped silicon solar cell  

Microsoft Academic Search

The resistance to radiation damage of an n(+)p boron doped silicon solar cell is improved by lithium counterdoping. Even though lithium is an n-dopant in silicon, the lithium is introduced in small enough quantities so that the cell base remains p-type. The lithium is introduced into the solar cell wafer by implantation of lithium ions whose energy is about 50

I. Weinberg; H. W. Brandhorst Jr.

1986-01-01

78

Lithium counterdoped silicon solar cell  

Microsoft Academic Search

The resistance to radiation damage of an n(+)p boron doped silicon solar cell is improved by lithium counterdoping. Even though lithium is an n-dopant in silicon, the lithium is introduced in small enough quantities so that the cell base remains p-type. The lithium is introduced into the solar cell wafer by implantation of lithium ions whose energy is about 50

I. Weinberg; Brandhorst H. W. Jr

1984-01-01

79

The photochemical heat pipe  

Microsoft Academic Search

The performance of a solar collector system for high temperature heat delivery based on a photochromic reaction is discussed. The system consists of a non-focusing collector and a reactor integrated into a flow system. In the collector, kept close to ambient temperature, the chemical potential of the photochromic system is increased through an endothermic photochemical reaction and is used to

B. Carlsson; G. Wettermark

1978-01-01

80

Panel for solar energy cells  

Microsoft Academic Search

A panel for mounting solar energy cells, and particularly those cells upon which light is to be concentrated, includes an enclosure for holding the cells and has at least one wall formed from a good conductor of heat. The cells are mounted within the enclosure on a resinous cushion that is a relatively good conductor of heat and a poor

Varadi

1977-01-01

81

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

SciTech Connect

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.

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

1988-04-01

82

Photochemical solar energy conversion utilizing semiconductors localized in membrane-mimetic systems  

SciTech Connect

Extending the frontiers of colloidal photochemistry and colloidal electrochemistry to solar photochemistry research had been the main objective of this research. More specific objectives of this proposal include the examination of semiconductor-particle-mediated photoelectron transfer and photoelectric effects in different membrane mimetic systems. Emphasis had been placed on developing bilayer lipid membranes and Langmuir-Blodgett films as new membrane-mimetic systems, as well as on the characterization and utilization of these systems.

Fendler, J.H.

1991-08-31

83

Large Retractable Solar Cell Array.  

National Technical Information Service (NTIS)

The main activity on the Large Retractable Solar Cell Array (LRSCA) program during the third quarterly reporting period consisted of the completion of the analysis of a majority of the major subsystem components, start of detailed drawings, completion of ...

G. Wolff E. O. Felkel

1969-01-01

84

Lithium Implanted Solar Cells, Data.  

National Technical Information Service (NTIS)

The report contains the identification and processing description of all samples processed and the tabulated measurement data obtained on phosphorus diffused, lithium implanted, p-type silicon solar cell blanks. (Author)

D. A. Smith J. L. Hartke

1973-01-01

85

Thin-film solar cells  

Microsoft Academic Search

The rapid progress that is being made with inorganic thin-film photovoltaic (PV) technologies, both in the laboratory and in industry, is reviewed. While amorphous silicon based PV modules have been around for more than 20 years, recent industrial developments include the first polycrystalline silicon thin-film solar cells on glass and the first tandem solar cells based on stacks of amorphous and

Armin G. Aberle

2009-01-01

86

CCMR: Nanocrystal Sensitized Solar Cells  

NSDL National Science Digital Library

Nanocrystal sensitized solar cells demonstrate a possible cheap solution to practical device manufacture. This research examined the feasibility of using lead sulfide nanocrystals to sensitize tin dioxide and titanium dioxide substrates for the purpose of making a functioning photovoltaic device. Challenges included optimizing the substrate materials as well as the thin films made from them. Results indicate that titanium dioxide produces more suitable thin films than tin dioxide. Also, the methods employed did produce a functioning solar cell after optimization.

Perry, Alexis

2009-08-15

87

Radiation effects in solar cells  

NASA Astrophysics Data System (ADS)

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.

Imaizumi, Mitsuru; Ohshima, Takeshi

2013-05-01

88

Hydrogen generation from the chlorophyll water splitting reaction Photochemical conversion and solar energy storage  

NASA Astrophysics Data System (ADS)

In this paper we describe the developments leading to the production of hydrogen and organic fuels from water and carbon dioxide using sunlight and the chlorophyll extracted from green plants. Product analyses were made by a variety of physical measurements. The conversion of light into electrochemical potential is depicted in terms of the photoactivation overpotential derived from the photooxidation of hydrated chlorophyll aggregates. The chlorophyll functions as the photocatalyst, reducing and oxidizing the water to yield hydrogen and oxygen through a one-electron cyclic pathway that is readily observed by electron spin resonance measurements. The significance of the in vitro solar energy storage experiments relative to the long-term solution of the energy crisis is discussed.

Fong, F. K.

89

Terrestrial concentrator solar cell module  

SciTech Connect

This patent describes a solar cell module having a plurality of discrete cell units wherein each cell unit constitutes a tandem cell comprising an upper cell of a first semiconductive material and a lower cell of a second semiconductive material. It comprises a housing having a base and an upper portion; primary outer lens elements supported by the housing upper portion; a secondary radiant energy concentrating element associated with each primary lens element for protecting the carrier tape against incident light; each of the solar cell units being thermally coupled to the base; and parallel spaced strips of conductive material carried by the tape with means for separately connecting the strips to predetermined contact surfaces of the upper and lower cells of each cell unit.

Fraas, L.M.; Mansoori, N.; Kim, N.B.; Avery, J.E.

1992-06-02

90

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

SciTech Connect

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.

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

1992-12-01

91

Interdigitated back contact solar cells  

NASA Astrophysics Data System (ADS)

The interdigitated back contact solar cell (IBC cell) was shown to possess a number of advantages for silicon solar cells, which operate at high concentration. 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, and 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 discrepancies between various experimental measurements of bandgap narrowing.

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

1980-08-01

92

Lithium counterdoped silicon solar cell  

SciTech Connect

The resistance to radiation damage of an n(+)p boron doped silicon solar cell is improved by lithium counterdoping. Even though lithium is an n-dopant in silicon, the lithium is introduced in small enough quantities so that the cell base remains p-type. The lithium is introduced into the solar cell wafer by implantation of lithium ions whose energy is about 50 keV. After this lithium implantation, the wafer is annealed in a nitrogen atmosphere at 375 C for two hours. NASA

Weinberg, I.; Brandhorst, H.W., Jr.

1984-11-01

93

Lithium Counterdoped Silicon Solar Cell.  

National Technical Information Service (NTIS)

The resistance to radiation damage of an n(+)p boron doped silicon solar cell is improved by lithium counterdoping. Even though lithium is an n-dopant in silicon, the lithium is introduced in small enough quantities so that the cell base remains p-type. T...

I. Weinberg H. W. Brandhorst

1984-01-01

94

Design of a photochemical converter for solar energy using semiconductor electrodes  

SciTech Connect

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.

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

1993-07-01

95

Photon upconversion for thin film solar cells  

Microsoft Academic Search

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

J. de Wild

2012-01-01

96

Investigation of Sustained Arc under Solar Cell  

Microsoft Academic Search

We have so far studied the sustained arc between solar array strings using solar array coupons. The solar cells are connected electrically in series by interconnectors. The interconnector is conductor and is weld at both backside and top of cells. The solar array paddle undergoes the mechanical stress due to thermal cycles in orbit. This stress may cause the separation

Kazuhiro Toyoda; Mengu Cho; Shirou Kawakita; Masato Takahashi

2010-01-01

97

Photochemical internalization enhances the efficacy of bleomycin in malignant glioma cells  

NASA Astrophysics Data System (ADS)

The utility of photochemical internalization (PCI) for the treatment of malignant gliomas was investigated in vitro using: (1) monolayers consisting of F98 rat glioma cells, and (2) human glioma spheroids established from biopsy-derived glioma cells. In both cases, the cytotoxicity of AlPcS2a- based PCI of bleomycin was compared to: (1) AlPcS2a-PDT, and (2) bleomycin. In all cases, monolayers and spheroids were incubated in AlPcS2a (18 h), bleomycin (4 h), or AlPcS2a (18 h) + bleomycin (4 h) and were subsequently exposed to 670 nm light. Toxicity was evaluated using colony formation assays or spheroid growth kinetics. Neither F98 rat glioma cells in monolayer nor human glioma spheroids were found to be particularly sensitive to the effects of low irradiance (5 mW cm-2), low radiant exposure (1.5 J cm-2) AlPcS2a -PDT. Bleomycin was found to be moderately toxic to F98 cells in monolayer at relatively low concentrations - incubation of F98 cells in 0.1 ?g ml-1 for 4 hours resulted in 80% survival. Under similar incubation conditions, the effects of bleomycin on human glioma spheroids were negligible. In both in vitro systems investigated, the PCI effect was found to be significant. For example, PCI consisting of a radiant exposure of 1.5 J cm-2 together with 0.25 ?g ml-1 bleomycin resulted in approximately 20 and 65 % survival of F98 rat glioma cells and human glioma spheroids respectively. These results show that AlPcS2a-mediated PCI can be used to enhance the efficacy of chemotherapeutic agents such as bleomycin in malignant gliomas.

Madsen, Steen J.; Blickenstaff, Joseph W.; Vo, Van; Angell-Petersen, Even; Hirschberg, Henry

2009-02-01

98

Development of concentrator solar cells  

SciTech Connect

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.

Not Available

1994-08-01

99

Enhanced cellular delivery of cell-penetrating peptide-peptide nucleic acid conjugates by photochemical internalization.  

PubMed

Cell-penetrating peptides (CPPs) have been widely used for a cellular delivery of biologically relevant cargoes including antisense peptide nucleic acids (PNAs). Although chemical conjugation of PNA to a variety of CPPs significantly improves the cellular uptake of the PNAs, bioavailability (antisense activity) is still limited by endocytotic entrapment. We have shown that this low bioavailability can be greatly improved by combining CPP-PNA conjugate administration with a photochemical internalization technique using photosensitizers such as aluminum phthalocyanine (AlPcS(2a)) or tetraphenylporphyrin tetrasulfonic acid (TPPS). Cellular uptake of the PNA conjugates were evaluated by using a sensitive cellular method with HeLa pLuc705 cells based on the splicing correction of luciferase gene by targeting antisense oligonucleotides to a cryptic splice site of the mutated luciferase gene. The cellular efficacy of CPP conjugates were evaluated by measuring luciferase activity as a result of splicing correction and was also confirmed by RT-PCR analysis of luciferase pre-mRNA. PMID:21053145

Shiraishi, Takehiko; Nielsen, Peter E

2011-01-01

100

Silicon concentrator solar cell research  

SciTech Connect

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.

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

101

Photochemical solar energy conversion utilizing semiconductors localized in membrane mimetic systems  

NASA Astrophysics Data System (ADS)

Different membrane mimetic systems continue to be exploited as media for organizing components of the artificial photosynthetic apparatus. Surfactant vesicles, polymerized surfactant vesicles, Bilayer Lipid Membranes (BLMs), and Langmuir-Blodgett (LB) films are used as membrane mimetic systems. Catalyst-coated colloidal semiconductor particles are employed as sensitizers and relays in sacrificial half cells. Emphasis in our studies is placed on obtaining fundamental information on photoelectron transport. The BLM-supported colloidal semiconductors provide the most suitable media since photoelectron transfer processes can be monitored by simultaneous electrical and spectroscopic measurements. Advantage is taken of the insight gained from mechanistic investigations of vesicles and BLMs in the construction of more elaborate semiconductor-particle-containing LB films.

Fendler, Janos H.; Baral, Subhash

102

Scanning Probe Microscopy of Organic Solar Cells  

NASA Astrophysics Data System (ADS)

Nanostructured composites of organic semiconductors are a promising class of materials for the manufacture of low-cost solar cells. Understanding how the nanoscale morphology of these materials affects their efficiency as solar energy harvesters is crucial to their eventual potential for large-scale deployment for primary power generation. In this thesis we describe the use of optoelectronic scanning-probe based microscopy methods to study this efficiency-structure relationship with nanoscale resolution. In particular, our objective is to make spatially resolved measurements of each step in the power conversion process from photons to an electric current, including charge generation, transport, and recombination processes, and correlate them with local device structure. We have achieved two aims in this work: first, to develop and apply novel electrically sensitive scanning probe microscopy experiments to study the optoelectronic materials and processes discussed above; and second, to deepen our understanding of the physics underpinning our experimental techniques. In the first case, we have applied conductive-, and photoconductive atomic force (cAFM & pcAFM) microscopy to measure both local photocurrent collection and dark charge transport properties in a variety of model and novel organic solar cell composites, including polymer/fullerene blends, and polymer-nanowire/fullerene blends, finding that local heterogeneity is the rule, and that improvements in the uniformity of specific beneficial nanostructures could lead to large increases in efficiency. We have used scanning Kelvin probe microscopy (SKPM) and time resolved-electrostatic force microscopy (trEFM) to characterize all-polymer blends, quantifying their sensitivity to photochemical degradation and the subsequent formation of local charge traps. We find that while trEFM provides a sensitive measure of local quantum efficiency, SKPM is generally unsuited to measurements of efficiency, less sensitive than trEFM, and of greater utility in identifying local changes in steady-state charge density that can be associated with charge trapping. In the second case, we have developed a new understanding of charge transport between a sharp AFM tip and planar substrates applicable to conductive and photoconductive atomic force microscopy, and shown that hole-only transport characteristics can be easily obtained including quantitative values of the charge carrier mobility. Finally, we have shown that intensity-dependent photoconductive atomic force microscopy measurements can be used to infer the 3D structure of organic photovoltaic materials, and gained new insight into the influence vertical composition of the these devices can have on their open-circuit voltage and its intensity dependence.

Reid, Obadiah G.

103

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

Microsoft Academic Search

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.

C. M. Fortmann; S. S. Hegedus

1992-01-01

104

New methods for solar cells measurement by LED solar simulator  

Microsoft Academic Search

A solar simulator for solar cells is an important tool to measure their performance. At present, xenon and halogen lamp is used at most laboratories. It is considerably accurate, but the facility is so large and so expensive. Therefore, a solar simulator using LED (light-emitting diode) lamps is proposed, that is low-cost and portable, and was invented to its capability.

S. Kohraku; K. Kurokawa

2003-01-01

105

Solar cell array  

Microsoft Academic Search

An array of photovoltaic cells in a back wall-type configuration supported by a rigid transparent vitreous substrate, such as glass, for admitting incident radiation to the cells is described. A plurality of cells are interconnected into a desired electrical configuration by one or more layers of electrically conducting materials which overlie the entire heterojunction of each cell to minimize the

J. F. Jordan; C. M. Lampkin

1982-01-01

106

Solar cell array  

Microsoft Academic Search

An array of photovoltaic cells in a back wall-type configuration supported by a rigid transparent vitreous substrate, such as glass, for admitting incident radiation to the cells is described. A plurality of cells are interconnected into a desired electrical configuration by one or more layers of electrically conducting materials which overlie substantially the entire heterojunction of each cell to minimize

J. F. Jordan; C. M. Lampkin

1981-01-01

107

Key Physical Mechanisms in Nanostructured Solar Cells  

SciTech Connect

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.

Dr Stephan Bremner

2010-07-21

108

Titania solar cells: new photovoltaic technology  

Microsoft Academic Search

Titania solar cells are a new type of photovoltaic device invented by Professor Michael Grätzel at Ecole Polytechnique Federale de Lausanne (Switzerland). Titania solar cells convert sunlight directly into electricity through a process similar to photosynthesis. It has performance advantages over other solar cells, which include the ability to perform well in low light and shade, and to perform consistently

George Phani; Gavin Tulloch; David Vittorio; Igor Skryabin

2001-01-01

109

Method of fabricating solar cell modules  

Microsoft Academic Search

The solar cell module of this invention is fabricated by placing an array of solar cells in a suitable mold having a bottom surface, an entry port and an exit port. A light transparent superstrate effectively serves as the top for the mold and is placed over the array of solar cells in the mold. The superstrate is spaced from

W. B. Andrulitis; W. T. Kurth; S. G. Miles

1980-01-01

110

Concentrator solar cell array module  

Microsoft Academic Search

A concentrator solar cell array module is described having a metallic heat sink with a planar mounting surface. A semiconductor spacer is provided. The semiconductor spacer is provided with a layer of insulating material in the form of silicon oxide. The silicon oxide surface is secured to the mounting surface of the heat sink by a thermally conductive adhesive. A

R. M. Diamond; K. S. Ling; A. G. Winterer

1979-01-01

111

A novel chlorophyll solar cell  

NASA Astrophysics Data System (ADS)

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

Ludlow, J. C.

112

Mixed ternary heterojunction solar cell  

DOEpatents

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.

Chen, Wen S. (Seattle, WA); Stewart, John M. (Seattle, WA)

1992-08-25

113

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

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

Sampath-Wiley, Priya; Jahnke, Leland S

2010-11-24

114

Solar cell calibration by balloon flight  

Microsoft Academic Search

An overview of the manufacture and calibration by balloon flight of primary standard solar batteries is presented as follows. Primary standard solar battery cells of micro N electrode Back Surface Reflector (BSR) and micro N electrode Back Surface Field and Reflector (BSFR) type were produced, and primary solar battery modules of both types were assembled each with four cells selected

Sumio Matsuda; Takashi Tamura; Masato Uesugi

1992-01-01

115

The Case for the Large Scale Development of Solar Energy  

ERIC Educational Resources Information Center

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)

O'Reilly, S. A.

1977-01-01

116

The Case for the Large Scale Development of Solar Energy  

ERIC Educational Resources Information Center

|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)|

O'Reilly, S. A.

1977-01-01

117

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

PubMed Central

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.

2013-01-01

118

Solar cell junction processing system  

Microsoft Academic Search

An integrated system and process for the continuous formation of p-n junctions in solar cells in a cost-effective manner and under computer control. The integrated system essentially comprises an ion beam implanter, an electron beam annealer and a combination vacuum lock-and-wafer transport system, all disposed within a unitary housing maintained under a common vacuum environment. The integrated system employs no

A. J. Armini; R. G. Little

1982-01-01

119

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...

120

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

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

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

2007-01-01

121

Current status of silicon solar cell technology  

Microsoft Academic Search

In quest of higher efficiency, major progress has occurred in solar cell technology during the last five years. In this period cell efficiency has climbed about 50 percent. Technical approaches leading to increased output include back surface fields (n+-p-p+structures), shallow junctions, improved antireflection coatings, surface texturizing, and fine grid patterns on the cell surface. The status of current solar cell

H. W. Jr

1975-01-01

122

Silicon concentrator solar cell development  

NASA Astrophysics Data System (ADS)

This project involved the development and supply of 550 silicon concentrator solar cells for use in prototype point-focus concentrator modules. The cells were to have a designed illumination area of 12.5 by 12.5 mm and to be designed for use with prismatic covers at a geometric concentration ratio of 200X. The target efficiency of 24 percent was comfortably exceeded, with efficiencies as high as 25.2 percent reached in the designed concentration ratio range. A combined lens/cell efficiency of 24.4 percent was measured at Sandia using a cell supplied during this project and a point focus Fresnel lens. Subsequently, a peak module efficiency of 20.3 percent was achieved at Sandia using 12 cells and lenses. This is believed to be the first photovoltaic module to surpass the 20 percent efficiency milestone.

Green, Martin A.; Jianhua, Zhao; Aihua, Wang; Blakers, A. W.

1990-05-01

123

In situ laser-induced photochemical silver substrate synthesis and sequential SERS detection in a flow cell  

Microsoft Academic Search

A new, simple, and effective approach for multianalyte sequential surface-enhanced Raman scattering (SERS) detection in a\\u000a flow cell is reported. The silver substrate was prepared in situ by laser-induced photochemical synthesis. By focusing the\\u000a laser on the 320 ?m inner diameter glass capillary at 0.5 ml\\/min continuous flow of 1 mM silver nitrate and 10 mM sodium citrate\\u000a mixture, a SERS active silver spot

Krisztian Herman; László Szabó; Loredana F. Leopold; Vasile Chi?; Nicolae Leopold

2011-01-01

124

Investigation of Sustained Arc under Solar Cell  

NASA Astrophysics Data System (ADS)

We have so far studied the sustained arc between solar array strings using solar array coupons. The solar cells are connected electrically in series by interconnectors. The interconnector is conductor and is weld at both backside and top of cells. The solar array paddle undergoes the mechanical stress due to thermal cycles in orbit. This stress may cause the separation of interconnector welding backside of cells. If the interconnector is separated from the cell, the string circuit is opened. However solar cells can generate voltage. If the separated interconnector attached to the cell again, the current can flow. If the path between interconnector and cell is formed by insulated adhesive, sustained arc can occur between the separated interconnector and cell. In this paper, the sustained arc between interconnector and cells was investigated experimentally.

Toyoda, Kazuhiro; Cho, Mengu; Kawakita, Shirou; Takahashi, Masato

125

Energy Conversion: Nano Solar Cell  

NASA Astrophysics Data System (ADS)

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 cslash/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.

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

2009-09-01

126

Epitaxial thin-film Si solar cells  

Microsoft Academic Search

Most types of thin-film solar cells imply a radical departure from the dominant bulk crystalline Si technology. This is not the case for epitaxial thin-film solar cells. In this technology, a high quality Si layer is deposited epitaxially on a low-cost Si substrate (e.g. cast Upgraded Metallurgical Grade silicon or high-throughput Si ribbons) and processed into a solar cell. This

G. Beaucarne; F. Duerinckx; I. Kuzma; K. Van Nieuwenhuysen; H. J. Kim; J. Poortmans

2006-01-01

127

Bypass diode for a solar cell  

DOEpatents

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.

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

128

New materials for nanocrystal solar cells  

Microsoft Academic Search

New organic and inorganic materials for nanocrystal solar cells are reported with descriptions and basic characterization of their applicability. Brief background is presented regarding the fundamental operation of nanocrystal-polymer solar cells as context for the body of this work. New colloidal nanocrystals synthesized for solar cells include CdTe tetrapods for improved light absorption and electron transport, and Type II core\\/shell

Delia Jane Milliron

2004-01-01

129

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

NASA Astrophysics Data System (ADS)

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.

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

2005-04-01

130

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

Microsoft Academic Search

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)

Yunlin Zhang; Mingliang Liu; Boqiang Qin; Sheng Feng

2009-01-01

131

Interdigitated Back Contact Solar Cells. Annual Report.  

National Technical Information Service (NTIS)

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 ...

M. S. Lundstrom R. J. Schwartz

1980-01-01

132

The MIS and MISIM solar cell  

Microsoft Academic Search

The insertion of a very thin insulating layer (less than 20 A) between the metal and the semiconductor of a Schottky solar cell can dramatically improve the open circuit voltage of the cell. The resulting MIS structure is shown to be electronically equivalent to a p-n junction device, provided that minority current flow is dominant. The MISIM solar cell, a

M. A. Green; R. B. Godfrey

1978-01-01

133

Interconnect for electrically connecting solar cells  

SciTech Connect

This paper describes a solar cell array. It comprises: solar cells arranged in an array, each the solar cell having an upper electrical contact and a lower electrical contact; interconnects for electrically connecting the solar cells, each the interconnect comprising: a stress relief part comprised of a single longitudinally extended member having a central portion and first and second end portions defining a planar surface; a first connecting part attached to the upper contact of a respective one of the solar cells; a second connecting part attached to the lower contact of a solar cell adjacent to the respective one of the solar cells; means for joining the first and second connecting parts to respective first and second end portions of the stress relief part such that the central portion of the stress relief part is disposed substantially parallel to adjacent edges of the solar cells which are electrically connected by the interconnect and such that the planar surface defined by the stress relief part extends substantially perpendicularly relative to the top surface of the solar cell array.

Gaddy, E.M.

1991-04-09

134

Very High Efficiency Solar Cell Modules  

SciTech Connect

The Very High Efficiency Solar Cell (VHESC) program is developing integrated optical system - PV modules for portable applications that operate at greater than 50% efficiency. We are integrating the optical design with the solar cell design, and have entered previously unoccupied design space. Our approach is driven by proven quantitative models for the solar cell design, the optical design, and the integration of these designs. Optical systems efficiency with an optical efficiency of 93% and solar cell device results under ideal dichroic splitting optics summing to 42.7 {+-} 2.5% are described.

Barnett, A.; Kirkpatrick, D.; Honsberg, C.; Moore, D.; Wanlass, M.; Emery, K.; Schwartz, R.; Carlson, D.; Bowden, S.; Aiken, D.; Gray, A.; Kurtz, S.; Kazmerski, L., et al

2009-01-01

135

Luminescence radiation spectroscopy of silicon solar cells  

NASA Astrophysics Data System (ADS)

At present there are known many of diagnostic methods of detection large crystal lattice defects of silicon solar cells. This paper deals about results of new potential in to use one of characteristics luminescence radiation for detection defects of solar cells. So polarization spectroscopy of defect in solar cells may be used to fitting characterization of silicon solar cells. And this can lead to understand the electrical properties of defects in silicon solar cells and study of really formation defects. We used extending existing electroluminescence technology about polarization spectroscopy to yield the polarization of luminescence radiation by defect in solar cells. Radiation emitted by the solar cell has a wave character that can interact with the silicon structures or hypothetically thin reflectance layer of solar cells. In our research we can observed the linear partially polarization luminescence light on poly-silicon crack defect. Spectral response of using CCD camera is approximately 300 to 1100 nm. Sinusoid dependence of luminescence intensity on the angle of linear polarization analyzer rotation shown this fact. The degree of polarization depends on the material, in this case the character of defect. Polarized light can be obtained in various ways. This fact opens up for potential next new questions in this widely course of study diagnostics defects silicon solar cells.

Stojan, R.; Van?k, J.; Malý, M.; Gvritishvili, R.; Tománek, P.; Frantík, O.

2013-09-01

136

Solar cells using quantum funnels.  

PubMed

Colloidal quantum dots offer broad tuning of semiconductor bandstructure via the quantum size effect. Devices involving a sequence of layers comprised of quantum dots selected to have different diameters, and therefore bandgaps, offer the possibility of funneling energy toward an acceptor. Here we report a quantum funnel that efficiently conveys photoelectrons from their point of generation toward an intended electron acceptor. Using this concept we build a solar cell that benefits from enhanced fill factor as a result of this quantum funnel. This concept addresses limitations on transport in soft condensed matter systems and leverages their advantages in large-area optoelectronic devices and systems. PMID:21827197

Kramer, Illan J; Levina, Larissa; Debnath, Ratan; Zhitomirsky, David; Sargent, Edward H

2011-08-11

137

Lithium counterdoped silicon solar cell  

SciTech Connect

A radiation damage resistant solar cell is described comprising a wafer of p-type boron doped silicon having lithium ions implanted therein in small enough quantities such that the wafer remains p-type after lithium addition. The wafer has an n/sup +/ region formed by phosphorus ions implanted therein adjacent to a surface of the wafer, a first electrical contact on the surface adjacent to the n/sup +/ region, and a second electrical contact on an opposite surface of the wafer.

Weinberg, I.; Brandhorst, H.W. Jr.

1986-08-26

138

Improved monolithic tandem solar cell  

DOEpatents

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.

Wanlass, M.W.

1991-04-23

139

Radiation damage in biomimetic dye molecules for solar cells.  

PubMed

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 H(2)) 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 E(F) 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. PMID:19968355

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

2009-12-01

140

Upconverter solar cells: materials and applications  

Microsoft Academic Search

Spectral conversion of sunlight is a promising route to reduce spectral mismatch losses that are responsible for the major part of the efficiency losses in solar cells. Both upconversion and downconversion materials are presently explored. In an upconversion process, photons with an energy lower than the band gap of the solar cell are converted to higher energy photons. These higher

J. de Wild; A. Meijerink; J. K. Rath; W. G. J. H. M. van Sark; R. E. I. Schropp

2011-01-01

141

Calibration of Solar Cells in Terrestrial Sunlight.  

National Technical Information Service (NTIS)

A method of calibrating solar cells in sunlight is described. This method has been used for at least 15 years, and produces a value of the solar cell's short circuit current for any predetermined space of terrestrial condition. The main advantage of this ...

M. A. H. Davies C. Goodbody

1991-01-01

142

Solar cell parameter extraction using genetic algorithms  

Microsoft Academic Search

In this paper, a technique based on genetic algorithms is proposed for improving the accuracy of solar cell parameters extracted using conventional techniques. The approach is based on formulating the parameter extraction as a search and optimization problem. Current-voltage data used were generated by simulating a two-diode solar cell model of specified parameters. The genetic algorithm search range that simulates

Joseph A. Jervase; Hadj Bourdoucen; Ali Al-Lawati

2001-01-01

143

Si concentrator solar cell development. [Final report  

SciTech Connect

This is the final report of a program to develop a commercial, high-efficiency, low-cost concentrator solar cell compatible with Spectrolab`s existing manufacturing infrastructure for space solar cells. The period covered is between 1991 and 1993. The program was funded through Sandia National Laboratories through the DOE concentrator initiative and, was also cost shared by Spectrolab. As a result of this program, Spectrolab implemented solar cells achieving an efficiency of over 19% at 200 to 300X concentration. The cells are compatible with DOE guidelines for a cell price necessary to achieve a cost of electricity of 12 cents a kilowatthour.

Krut, D.D. [Spectrolab, Inc., Sylmar, CA (United States)

1994-10-01

144

US Polycrystalline Thin Film Solar Cells Program.  

National Technical Information Service (NTIS)

The Polycrystalline Thin Film Solar Cells Program, part of the United States National Photovoltaic Program, performs R and D on copper indium diselenide and cadmium telluride thin films. The objective of the Program is to support research to develop cells...

H. S. Ullal K. Zweibel R. L. Mitchell

1989-01-01

145

Nanowire-based All Oxide Solar Cells  

SciTech Connect

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.

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

2008-12-07

146

Multiple quantum well top cells for multijunction concentrator solar cells  

Microsoft Academic Search

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

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

147

Monolithic Cascade-Type Solar Cells.  

National Technical Information Service (NTIS)

Solar cells consist of a semiconductor base, a bottom cell with a band-gap energy of E1, and a top cell with a band-gap energy of E2, and 0.96 E1 1.36 eV and (0.80 E + 0.77) eV E2 (0.80 E1 + 0.92) eV. A monolithic cascade-type solar cell was prepared with...

S. Yamamoto A. Shibukawa M. Yamaguchi

1985-01-01

148

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

NASA Astrophysics Data System (ADS)

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.

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

1999-06-01

149

Porphyrin-sensitized solar cells.  

PubMed

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

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

2012-10-01

150

Integration of Solar Cells on Top of CMOS Chips Part I: aSi Solar Cells  

Microsoft Academic Search

We present the monolithic integration of deep- submicrometer complementary metal-oxide-semiconductor (CMOS) microchips with a-Si:H solar cells. Solar cells are manufactured directly on the CMOS chips. The microchips maintain comparable electronic performance, and the solar cells show efficiency values above 7%. The yield of photovoltaic cells on planarized CMOS chips is 92%. This integration allows integrated energy harvesting using established process

Jiwu Lu; Alexey Y. Kovalgin; Karine H. M. van der Werf; Ruud E. I. Schropp; Jurriaan Schmitz

2011-01-01

151

Characterising dye-sensitized solar cells  

NASA Astrophysics Data System (ADS)

With growing energy and environmental concerns due to fossil fuel depletion and global warming there is an increasing attention being attracted by alternative and/or renewable sources of power such as biomass, hydropower, geothermal, wind and solar energy. In today's society there is a vast and in many cases not fully appreciated dependence on electrical power for everyday life and therefore devices such as PV cells are of enormous importance. The more widely used and commercially available silicon (semiconductor) based cells currently have the greatest efficiencies, however the manufacturing of these cells is complex and costly due to the cost and difficulty of producing and processing pure silicon. One new direction being explored is the development of dye-sensitised solar cells (DSSC). The SFI Strategic Research Centre for Solar Energy Conversion is a new research cluster based in Ireland, formed with the express intention of bringing together industry and academia to produce renewable energy solutions. Our specific area of research is in biomimetic dye sensitised solar cells and their electrical properties. We are currently working to develop test equipment, and optoelectronic models describing the performance and behaviors of dye-sensitised solar cells (Grätzel Cells). In this paper we describe some of the background to our work and also some of our initial experimental results. Based on these results we intend to characterise the opto-electrical properties and bulk characteristics of simple dye-sensitised solar cells and then to proceed to test new cell compositions.

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

2009-08-01

152

Solar cells based on gallium antimonide  

SciTech Connect

Liquid-phase epitaxy and diffusion from the gas phase have been used to create various kinds of GaSb-based solar cell structures intended for use in cascaded solar-radiation converters. A narrow-gap (GaSb) solar cell was studied in tandem based on a combination of semiconductors GaAs-GaSb (two p-n junctions) and GaInP/GaAs-GaSb (three p-n junctions). The maximum efficiency of photovoltaic conversion in GaSb behind the wide-gap cells is {eta} = 6.5% (at sunlight concentration ratio of 275X, AM1.5D Low AOD spectrum)

Andreev, V. M.; Sorokina, S. V.; Timoshina, N. Kh.; Khvostikov, V. P., E-mail: vikhv@scell.ioffe.ru; Shvarts, M. Z. [Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation)

2009-05-15

153

Present status of buried contact solar cells  

Microsoft Academic Search

Recent years have seen substantially increased performance for laboratory Silicon solar cells. The standard commercial screen-printing cell process sequence appears unable to take advantage of many of these improvements. Consequently, until recently, the efficiency of commercial cells has lagged considerably. The buried contact cell provides a commercial approach able to bridge this gap. During 1990 and 1991, the first results

M. A. Green; S. R. Wenham; J. Zhao; S. Bowden; A. M. Milne; M. Taouk; F. Zhang

1991-01-01

154

Solar Cell Calibration Experiments on Les-6.  

National Technical Information Service (NTIS)

The sixth Lincoln Laboratory Experimental Satellite (LES-6) was placed in a synchronous orbit on 26 September 1968. Among instrumentation on board is a solar cell calibration experiment to measure the V-I characteristics at various angles of solar inciden...

F. W. Sarles A. G. Stanley C. Burrowes

1968-01-01

155

Nanocomposites for organic and hybrid organic-inorganic solar cells  

Microsoft Academic Search

The importance of nanocomposites materials such as carbon nanotubes-polymers composites for the efficient realization of innovative solar cells based on organic as well hybrid organic-inorganic solar cells is more and more evident. We present a study on the realization of dye sensitized solar cells (DSSC) and sublimation deposited solar cells, considering the impact of using nanocomposite materials in the different

A. Reale; T. M. Brown; A. Di Carlo; F. Giannini; F. Brunetti; E. Leonardi; M. Lucci; M. L. Terranova; S. Orlanducci; E. Tamburri; F. Toschi; V. Sessa

2006-01-01

156

Photochemical solar energy conversion utilizing semiconductors localized in membrane-mimetic systems. Performance report, April 1, 1989--August 31, 1991  

SciTech Connect

Extending the frontiers of colloidal photochemistry and colloidal electrochemistry to solar photochemistry research had been the main objective of this research. More specific objectives of this proposal include the examination of semiconductor-particle-mediated photoelectron transfer and photoelectric effects in different membrane mimetic systems. Emphasis had been placed on developing bilayer lipid membranes and Langmuir-Blodgett films as new membrane-mimetic systems, as well as on the characterization and utilization of these systems.

Fendler, J.H.

1991-08-31

157

Simple Ion Implantation System for Solar Cells.  

National Technical Information Service (NTIS)

A project has been initiated to investigate simple but effective ion implantation and pulsed annealing techniques for the fabrication of high efficiency silicon solar cells. In particular, the method aims to eliminate the mass analyser and associated comp...

M. J. Kenny J. R. Bird H. G. Broe

1982-01-01

158

Advanced Silicon Space Solar Cells Using Nanotechnology  

SciTech Connect

Application of nanotechnology and advanced optical structures offer new possibilities for improved radiation tolerance in silicon solar cells. We describe the application of subwavelength diffractive structures to enhance optical absorption near the surface, and thereby improve the radiation tolerance.

Gee, J.M.; Ruby, D.S.; Zaidi, S.H.

1999-03-31

159

Screen Printed Interdigitated Back Contact Solar Cell.  

National Technical Information Service (NTIS)

Interdigitated back contact solar cells were made by screen printing dopant materials onto the back surface of a semiconductor substrate in a pair of interdigitated patterns. These dopant materials were then diffused into the substrate to form junctions h...

C. R. Baraona G. A. Mazaris A. T. Chai

1983-01-01

160

Solar Cell Efficiency Tables (Version 34)  

SciTech Connect

Consolidated tables showing an extensive listing of the highest independently confirmed efficiencies for solar cells and modules are presented. Guidelines for inclusion of results into these tables are outlined and new entries since January, 2009 are reviewed.

Green, M. A.; Emery, K.; Hishikawa, Y.; Warta, W.

2009-01-01

161

Solar-cell testing and evaluation  

SciTech Connect

A two year study of the degradation effects in AlGaAs/GaAs solar cells is described. Illuminated current-voltage measurements were made during temperature and humidity cycling and time dependent degradation measurements were recorded.

Stefanakos, E.K.; Collis, W.J.

1982-04-01

162

Cascade solar cell having conductive interconnects  

DOEpatents

Direct ohmic contact between the cells in an epitaxially grown cascade solar cell is obtained by means of conductive interconnects formed through grooves etched intermittently in the upper cell. The base of the upper cell is directly connected by the conductive interconnects to the emitter of the bottom cell. The conductive interconnects preferably terminate on a ledge formed in the base of the upper cell.

Borden, Peter G. (Menlo Park, CA); Saxena, Ram R. (Saratoga, CA)

1982-10-26

163

Status of polycrystalline solar cell technologies  

Microsoft Academic Search

Thin-film cadmium telluride (CdTe) and thin-film copper indium diselenide (CIS) solar cells are discussed. The issues these technologies face before commercialization are addressed. The authors conclude that high-efficiency (15-18%) polycrystalline silicon modules will dominate the market in the near future, and impressive results for thin-film CdTe and CIS solar cells and their outdoor stability will attract increased interest in these

Vijay K. Kapur; Bulent M. Basol

1991-01-01

164

Towards upconversion for amorphous silicon solar cells  

Microsoft Academic Search

Upconversion of subbandgap light of thin film single junction amorphous silicon solar cells may enhance their performance in the near infrared (NIR). In this paper we report on the application of the NIR–vis upconverter ?-NaYF4:Yb3+(18%) Er3+(2%) at the back of an amorphous silicon solar cell in combination with a white back reflector and its response to infrared irradiation. Current–voltage measurements

J. de Wild; A. Meijerink; J. K. Rath; W. G. J. H. M. van Sark; R. E. I. Schropp

2010-01-01

165

Simplified solar cell material tester  

SciTech Connect

A method is described for testing quality of photovoltaic semiconductor material having a thickness of less than one minority carrier diffusion length, for use as solar cells, by determining the minority carrier diffusion length, comprising the steps of: preparing a thin slice of semiconductor material by polishing one side thereof, and preparing the other side thereof with a predetermined surface finish; coupling to both sides of the thin slice of semiconductor material with electrodes; directing lighting having a first predetermined wavelength onto the polished surface of the sice; measuring a first photovoltage developed at the electrodes while light at the first wavelength is applied to the slice; directing light having a second different predetermined wavelength onto the slice; adjusting the light intensity so that the photovoltage developed at the electrodes while light at the second wavelength is applied to the slice is substantially the same as the first photovoltage at the first wavelength; measuring a second intensity of illumination applied to the slice at the second wavelength; determining the ratio of the light intensity at one of the first and second wavelengths relative to the light intensity at the other of the first and second wavelengths; and ascertaining the minority carrier diffusion length from the ratio.

Garlick, G.F.J.

1987-04-07

166

Investigating dye-sensitised solar cells  

NASA Astrophysics Data System (ADS)

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

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

2010-04-01

167

Solar energy-conversion processes in organic solar cells  

NASA Astrophysics Data System (ADS)

Organic semiconducting materials have demonstrated attractive light-absorption and photocurrent-generation functions due to their delocalized ? electrons as well as intra-molecular and inter-molecular charge separation processes. On the other hand, organic semiconducting materials have easy property tuning, are mechanically flexible, and have large-area thin film formation properties. As a result, organic materials have become potential candidates in solar energy applications. This article will review critical energy-conversion processes in organic solar cells with the focus on singlet and triplet photovoltaic responses.

Xu, Zhihua; Zang, Huidong; Hu, Bin

2008-09-01

168

Monolithic solar cell panel of amorphous silicon  

Microsoft Academic Search

A monolithic solar cell panel has been fabricated using hydrogenated amorphous silicon (a-Si:H) as the semiconductor material. This device consists of a plate glass substrate bearing a number of long, narrow, parallel cells electrically connected in series along the lengths of the cells. It features several characteristics which make it uniquely attractive for large area devices (up to several sq

J. J. Hanak

1979-01-01

169

A hybrid soft solar cell based on the mycobacterial porin MspA linked to a sensitizer-viologen Diad.  

PubMed

A prototype of a nano solar cell containing the mycobacterial channel protein MspA has been successfully designed. MspA, an octameric transmembrane channel protein from Mycobacterium smegmatis, is one of the most stable proteins known to date. Eight Ruthenium(II) aminophenanthroline-viologen maleimide Diads (Ru-Diads) have been successfully bound to the MspA mutant MspAA96C via cysteine-maleimide bonds. MspA is known to form double layers in which it acts as nanoscopic surfactant. The nanostructured layer that is formed by (Ru-Diad)8MspA at the TiO2 electrode is photochemically active. The resulting "protein nano solar cell" features an incident photon conversion efficiency of 1% at 400 nm. This can be regarded as a proof-of-principle that stable proteins can be successfully integrated into the design of solar cells. PMID:23611424

Perera, Ayomi S; Subbaiyan, Navaneetha K; Kalita, Mausam; Wendel, Sebastian O; Samarakoon, Thilani N; D'Souza, Francis; Bossmann, Stefan H

2013-04-30

170

High efficiency amorphous silicon germanium solar cells  

Microsoft Academic Search

We report high-efficiency single-junction a-SiGe n-i-p solar cells deposited using rf PECVD on stainless steel (SS) substrates coated with metal\\/ZnO back-reflector (BR). The initial and stabilized active-area efficiencies have been improved to 12.5-13.0% and 10.4%, respectively, for 0.25 cm2 a-SiGe cells. The achievement of single-junction cells with such high efficiencies, equivalent to those for the state-of-the-art triple-junction solar cells, are

X. Liao; W. Du; X. Yang; H. Povolny; X. Xiang; X. Deng

2005-01-01

171

Nanoparticle Solar Cell Final Technical Report  

SciTech Connect

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.

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

2008-06-17

172

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

SciTech Connect

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.

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

1992-12-01

173

Catalysis of Photochemical Reactions.  

ERIC Educational Resources Information Center

|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)|

Albini, A.

1986-01-01

174

Catalysis of Photochemical Reactions.  

ERIC Educational Resources Information Center

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)

Albini, A.

1986-01-01

175

Thin-Film Technology in Intermediate Band Solar Cells: Advanced Concepts for Chalcopyrite Solar Cells  

NASA Astrophysics Data System (ADS)

Combining the two key factors of high performance and low cost into a single solar cell is the major challenge of research on photovoltaics. It is not easy to conceive a practical approach to such a device if not based on thin-film technology. Yet, it appears equally clear that current thin-film solar cells must upgrade their performance by some means in order to meet satisfactory energy conversion efficiencies. The incorporation of novel photovoltaic concepts, particularly the intermediate band solar cell, into thin-film technologies is expected to cross-fertilize both fields. In this chapter, we will outline the potential benefits ofthin-film intermediate band solar cells (TF-IBSC) and describe two different approaches toward its practical implementation. Particular attention will be devoted to devices based on chalcopyrite absorbers, currently leading the efficiency records of thin-film solar cells, and characterized by material properties well suited for this purpose.

Marrón, David Fuertes

176

Glass-Si Heterojunction Solar Cells.  

National Technical Information Service (NTIS)

Measurements on SnO2/n-Si heterojunction solar cells indicate the electron affinity of SnO2 about 0.85 eV greater than of Si. The principal dark current mechanism is electron emission; the operation is evidently similar to Schottky barrier cells. Rapid de...

R. L. Anderson G. Kent

1975-01-01

177

High-efficiency concentrator silicon solar cells  

SciTech Connect

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.

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

1990-11-01

178

Thin-Film Amorphorus Silicon Solar Cells.  

National Technical Information Service (NTIS)

The research programme on amorphous silicon solar cells with the structure Ni/TiOx/undoped amorphous silicon/'n+' amorphous silicon/stainless steel, was divided into three phases, the target being an 8% efficient 1 cm2 cell. It dealt with the growth of am...

R. J. Holwill J. McGill F. Riddoch P. Robinson S. D. Smith

1982-01-01

179

Automatic laser scanner for solar cells  

SciTech Connect

An instrument is described which controls a two-mirror scanning arrangement to raster a laser beam on a large-area solar cell. The short circuit current thus produced is plotted on an X--Y recorder, or recorded on a storage oscilloscope to study the spatial inhomogeneities of the cell.

Khanna, V.; Sastry, O.S.; Mukerjee, A.K.; Chopra, K.L.

1984-10-01

180

Thin Film Solar Cells for Terrestrial Applications.  

National Technical Information Service (NTIS)

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. ...

F. A. Shirland W. J. Biter E. W. Greeneigh T. P. Brody

1975-01-01

181

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

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

Reimund Goss; Gyözö Garab

2001-01-01

182

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

Microsoft Academic Search

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

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

183

Substitution of Aromatics by Amines at Room Temperature with Negative Energy of Activation: Amino peri-Arylenes as Metal-Free Components for Dye-Sensitized Solar Cells.  

PubMed

Substitution reactions of the chemically and photochemically unusually stable perylenetetracarboxylic bisimides proceed with neat amines even below room temperature where negative effective energies of activation were found. Analogous reactions proceed with naphthalenecarboximides as the lower homologues and terrylene and quaterrylene carboximides as the higher homologues. Bathochromically absorbing dyes with a novel pattern of substitution were obtained suitable as efficient metal-free light-absorbers for dye-sensitized solar cells. PMID:23988188

Langhals, Heinz; Christian, Sandra; Hofer, Alexander

2013-09-24

184

Simulations with CAO-3D model of photochemical response caused by precipitating electrons and solar protons at both polar regions during geomagnetic storms in October-November 2003 (preliminary comparison with MIPAS data)  

NASA Astrophysics Data System (ADS)

Relativistic electrons precipitating from radiation belts and solar protons can penetrate below 100 km into the polar atmosphere sometimes reaching the stratospheric levels wasting its energy and causing the ionization. It leads to additional production of NOx and HOx chemical com-pounds which destroy ozone in the chemical catalytic cycles. One of the strongest geomagnetic storms accompained by a strong Solar Proton Eevent (SPE) occured in October-November 2003. This period was covered also by observations with MIPAS instrument placed on board of ENVISAT satellite. The response of atmospheric chemical composition in both polar regions was studied with CAO-3D photochemical-transport model. In order to calculate ionization rates induced by precipitating electrons and solar protons during late October and November 2003, corresponding proton and electron fluxes in different energetic channels from GOES-10 and POES-15/16 have been used. The Atmospheric Ionization Module Osnabruck -AIMOS /Wissing and Kallenrode, 2009/ was used to calculate 3D fields of ionization rates separately by electrons and protons. Photochemical simulations showed that Northern and Southern po-lar regions had different photochemical response. Such difference mostly is the result of the two factors: polar cap expansion during the geomagnetic storm and the effect of horizontal transport. The calculated members of NOy, HOx, Cly families were preliminary compared with corresponding observed data measured by MIPAS and showed a general agreement. The sensitivity of calculated chemical response to the efficiencies of NOx and HOx production by en-ergetic particles have been studied also. This work was supported by Russian Science Foudation for Basic Research (grant 09-05-009949) and by contract 1-6-08 under Russian Sub-Program "Reseach and Investigation of Antarctica".

Krivolutsky, Alexei A.; Banin, Max; Maik Wissing, Jan; Vyushkova, Tatyana

185

Surface plasmon enhanced silicon solar cells  

NASA Astrophysics Data System (ADS)

Thin-film solar cells have the potential to significantly decrease the cost of photovoltaics. Light trapping is particularly critical in such thin-film crystalline silicon solar cells in order to increase light absorption and hence cell efficiency. In this article we investigate the suitability of localized surface plasmons on silver nanoparticles for enhancing the absorbance of silicon solar cells. We find that surface plasmons can increase the spectral response of thin-film cells over almost the entire solar spectrum. At wavelengths close to the band gap of Si we observe a significant enhancement of the absorption for both thin-film and wafer-based structures. We report a sevenfold enhancement for wafer-based cells at ?=1200 nm and up to 16-fold enhancement at ?=1050 nm for 1.25 ?m thin silicon-on-insulator (SOI) cells, and compare the results with a theoretical dipole-waveguide model. We also report a close to 12-fold enhancement in the electroluminescence from ultrathin SOI light-emitting diodes and investigate the effect of varying the particle size on that enhancement.

Pillai, S.; Catchpole, K. R.; Trupke, T.; Green, M. A.

2007-05-01

186

Photochemical instability of thiol-capped CdTe quantum dots in aqueous solution and living cells: process and mechanism.  

PubMed

The process and mechanism of photochemical instability of thiol-capped CdTe quantum dots (QDs) in aqueous solution were experimentally studied. After laser irradiation, the corresponding Raman bands of the Cd-S bond decreased obviously, indicating bond breaking and thiol detachment from the QD surfaces. Meanwhile, a photoinduced aggregation of QDs occurred with the hydrodynamic diameter increased to hundreds of nanometers from an initial 20 nm, as detected with dynamic light scattering measurements. The bleaching of the photoluminescence of QDs under laser irradiation could be attributed to the enhanced nonradiative transfer in excited QDs caused by increased surface defects due to the losing of thiol ligands. Singlet oxygen (1O2) was involved in the photooxidation of QDs, as revealed by the inhibiting effects of 1O2 quenchers of histidine or sodium azide (NaN3) on the photobleaching of QDs. The linear relationship in Stern-Volmer measurements between the terminal product and the concentration of NaN3 demonstrated that 1O2 was the main pathway of the photobleaching in QD solutions. By comparing the photostability of QDs in C2C12 cells with and without NaN3 treatment, the photooxidation effect of 1O2 on photobleaching of cellular QDs was confirmed. PMID:17887665

Ma, Jiong; Chen, Ji-Yao; Zhang, Yu; Wang, Pei-Nan; Guo, Jia; Yang, Wu-Li; Wang, Chang-Chun

2007-09-21

187

Towards highly efficient solar cells  

NASA Astrophysics Data System (ADS)

Suntech Power is the world's largest producer of solar panels and has delivered more than 20 million photovoltaic panels to more than 80 countries around the globe. Nature Photonics spoke with Stuart Wenham, chief technology officer at Suntech Power, to find out more about its activities and visions.

2012-03-01

188

Nanocrystal-polymer solar cells  

Microsoft Academic Search

The ability to structure materials on a nanometer dimension enables the processes of solar energy conversion to be optimized at their most fundamental length scale. In semiconducting nanocrystals, optical absorption and electrical transport can be tailored by changing their radius and length, respectively. The unique features of quantum confinement and shape manipulation characteristic for inorganic nanocrystals can be utilized to

Wendy Uyen Huynh

2002-01-01

189

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

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.

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

1984-08-01

190

Fill factor in organic solar cells.  

PubMed

The fill factor (FF) is an important parameter that determines the power conversion efficiency of an organic solar cell. There are several factors that can significantly influence FF, and these factors interact with each other very intricately. Due to this reason, a deep understanding of FF is quite difficult. Based on the three fundamental elements in the solar cell equivalent circuit, namely series resistance, shunt resistance and diode, we reviews the research progress in understanding on FF in organic solar cells. Physics lying behind the often-observed undesirable S-shaped J-V curves is also summarized. This paper aims to give a brief and comprehensive summary on FF from a fundamental point of view. PMID:23652780

Qi, Boyuan; Wang, Jizheng

2013-05-07

191

Solar cell parameter extraction using genetic algorithms  

NASA Astrophysics Data System (ADS)

In this paper, a technique based on genetic algorithms is proposed for improving the accuracy of solar cell parameters extracted using conventional techniques. The approach is based on formulating the parameter extraction as a search and optimization problem. Current-voltage data used were generated by simulating a two-diode solar cell model of specified parameters. The genetic algorithm search range that simulates the error in the extracted parameters was varied from ±5 to ±100% of the specified parameter values. Results obtained show that for a simulated error of ±5% in the solar cell model values, the deviation of the extracted parameters varied from 0.1 to 1% of the specified values. Even with a simulated error of as high as ±100%, the resulting deviation only varied from 2 to 36%. The performance of this technique is also shown to surpass the quasi-Newton method, a calculus-based search and optimization algorithm.

Jervase, Joseph A.; Bourdoucen, Hadj; Al-Lawati, Ali

2001-11-01

192

The characteristics of solar cells exposed to ?-radiation  

Microsoft Academic Search

We have investigated the characteristics of solar cells exposed to ?-radiation from the standpoint of developing such gamma cells utilizing nuclear spent fuels. The examination was performed for three representative types of solar cells, i.e. amorphous, monocrystalline and polycrystalline types. These solar cells were remotely irradiated using a highly intensive 60Co ?-source instead of spent fuels, and the induced current

Norikazu Horiuchi; Koichi Taniguchi; Masaki Kamiki; Takashi Kondo; Masanori Aritomi

1997-01-01

193

Multichromophore light harvesting in hybrid solar cells.  

PubMed

A new technologically relevant method for multichromophore sensitizing of hybrid blend solar cells is presented. Two dyes having complementary absorption in the UV-visible regions are individually adsorbed on nanocrystalline TiO(2) powder. These dyed TiO(2) nanoparticles are blended with an organic hole-conductor (HC) Spiro-OMeTAD in desired compositions and applied on a conducting substrate by doctor-blading at room temperature to fabricate multichromophore-sensitized hybrid blend solar cells. The external quantum efficiency (EQE) of the single hybrid layer system fabricated with two dyes, that absorb mainly UV (TPD dye) and visible regions (Ru-TPA-NCS dye), exhibited a clear panchromatic response with the sum of the EQE characteristics of each single dye cell. The first results of a multichromophore-sensitized solid-state solar cell showed J(sc) of 2.1 mA cm(-2), V(oc) of 645 mV, FF of 47% and efficiency of 0.65% at AM 1.5 G, 100 mW cm(-2) illumination intensity. The J(sc) of the multichromophore cell is the sum of the individually dyed solar cells. The process described here is technically very innovative and very simple in procedure. It has potentials to be adopted for panchromatic sensitization using more than two dyes in a single hybrid layer or layer-wise fabrication of a tandem structure at room temperature. PMID:21695348

Bandara, Jayasundera; Willinger, Katja; Thelakkat, Mukundan

2011-06-22

194

Gallium arsenide solar cell radiation damage study  

SciTech Connect

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 {minus} 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.

Maurer, R.H.; Herbert, G.A.; Kinnison, J.D. (The Johns Hopkins Univ., Applied Physics Lab., Laurel, MD (US)); Meulenberg, A. (COMSAT Lab., Clarksburg, MD (US))

1989-12-01

195

Electroluminescence from CdTe Solar Cells  

NASA Astrophysics Data System (ADS)

We have observed room-temperature electroluminescence (EL) from CdTe/CdS thin film solar cells. The spectral shape of the emission is similar to photoluminescence from the CdTe/CdS junction of the same devices. We attribute the electroluminescence to recombination of injected electrons and holes at the CdTe/CdS interface. The integrated electroluminescence intensity shows super-quadratic dependence on the device current. The EL intensity is shown to decrease after one-sun light soaking. These results demonstrate electroluminescence to be a promising characterization tool for CdTe/CdS solar cells. This work supported by the National Renewable Energy Laboratory (NREL).

Price, K. J.; Vasko, A.; Compaan, A. D.

2002-03-01

196

Optimum operating conditions of a solar cell panel and prediction of solar radiation in Sanaa, Yemen  

Microsoft Academic Search

Results of a study of the performance of solar cells under nominal operating conditions in Yemen are reported. The solar cell panel comprised 14 Si cells of .003 sq m surface area each, and was mounted on a rooftop with the solar radiation being measured by a pyranometer. Further monitoring was performed of the panel surface temperature, the ambient air

A. Khogali; M. R. I. Ramadan

1982-01-01

197

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

NASA Astrophysics Data System (ADS)

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

Sholin, Veronica

198

Process development for high-efficiency silicon solar cells.  

National Technical Information Service (NTIS)

Fabrication of high-efficiency silicon solar cells in an industrial environment requires a different optimization than in a laboratory environment. Strategies are presented for process development of high-efficiency silicon solar cells, with a goal of sim...

J. M. Gee P. A. Basore M. E. Buck D. S. Ruby W. K. Schubert

1991-01-01

199

Theoretical Quantification of Nonlinear Effects in Silicon Solar Cells.  

National Technical Information Service (NTIS)

An analytic model for the internal quantum efficiency of solar cells is presented. It is especially intended for explanation and quantitative analysis of nonlinear effects in silicon solar cells. The model differs from conventional ones in that it conside...

J. M. Ruiz

1986-01-01

200

Plastic solar cells with engineered interfaces  

NASA Astrophysics Data System (ADS)

We discuss here bulk-heterojunction polymer solar cells with engineered interfaces to achieve desired phase separations (vertical and horizontal), molecule orientations, ohmic contacts, and electronic properties for device performance maximization, and to enhance the device durability by eliminating corrosive interfacial layers. The strategies discussed include development of novel interfacial layers such as self-assembled organic layers and inorganic metal oxide layers, and using inverted cell architectures. Interface engineering leads to optimal active layer morphologies and to polymer ?- orientation, as well as maximum open circuit voltage. Using p-type NiO as the anode hole transporting/electron blocking layer results in dramatically enhanced device performance of P3HT/PCBM polymer solar cells with PCEs up to 5%. Electrical property and surface morphology investigations of NiO elucidate the mechanism for the enhanced performance. Other novel interfacial materials such as self-assembled organic monolayers and graphene oxide (GO) have also been incorporated into polymer solar cells to achieve comparable PCEs with improved device stability. Using ZnO as electron transporting/hole blocking layer and employing an inverted device architecture, polymer solar cells achieve desired molecule ?-orientation and vertical phase separation, therefore extremely high fill factors and promising power conversion efficiencies. In addition to interfacial layer materials, active layer components with state-of-the-art device performance, both polymer and small molecule developed in this laboratory, will also be discussed.

Guo, Xugang; Marks, Tobin J.

2013-03-01

201

Multi-junction solar cell device  

DOEpatents

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.

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

2007-12-18

202

Polymer-fullerene bulk heterojunction solar cells  

NASA Astrophysics Data System (ADS)

Organic solar cells have the potential to be low-cost and efficient solar energy converters, with a promising energy balance. They are made of carbon-based semiconductors, which exhibit favourable light absorption and charge generation properties, and can be manufactured by low temperature processes such as printing from solvent-based inks, which are compatible with flexible plastic substrates or even paper. In this review, we will present an overview of the physical function of organic solar cells, their state-of-the-art performance and limitations, as well as novel concepts to achieve a better material stability and higher power conversion efficiencies. We will also briefly review processing and cost in view of the market potential.

Deibel, Carsten; Dyakonov, Vladimir

2010-09-01

203

Photochemical decontamination of red cell concentrates with the silicon phthalocyanine Pc 4 and red light  

NASA Astrophysics Data System (ADS)

Virus inactivation in red blood cells concentrates (RBCC) is being studied in order to increase the safety of the blood supply. For this purpose we have been studying the silicon phthalocyanine (Pc 4), a photosensitizer activated with red light. Two approaches were used to achieve enhanced selectivity of Pc 4 for virus inactivation. One was formulation of Pc 4 in liposomes that reduce its binding to red cells. The other was the use of a light emitting diode (LED) array emitting at 700 nm. Vesicular stomatitis virus (VSV) infectivity served as an endpoint for virus kill in treated RBCC. Red cell hemolysis and circulatory survival in rabbits served as measures for red cell damage. Treatment of small aliquots of human RBCC with 2 (mu) M Pc 4 in liposomes and 10 J/cm2 of 700 nm LED light in the presence of the quenches of reactive oxygen species glutathione and trolox resulted in 6 log10 inactivation of VSV. Under these conditions hemolysis of treated red cells stored at 4 degree(s)C for 21 days was only slightly above that of control cells. Rabbit RBCC similarly treated circulated with a half life of 7.5 days compared with 10.5 days of control. It is concluded that Pc 4 used as described here may be useful for viral decontamination of RBCC, pending toxicological and clinical studies.

Ben-Hur, Ehud; Zuk, Maria M.; Oetjen, Joyce; Chan, Wai-Shun; Lenny, Leslie; Horowitz, Bernard

1999-07-01

204

Redox reaction in photochemical and ionizing irradiation systems.  

National Technical Information Service (NTIS)

This work presents a basic study of electron transfer reactions which could be involved in appropriate systems for photochemical conversion and storage of solar energy. The aim was to extend the knowledge to new photosensitizers and quenchers and to compa...

A. Slama-Schwok

1985-01-01

205

Photochemical production and behavior of hydroperoxyacids in heterotrophic bacteria attached to senescent phytoplanktonic cells.  

PubMed

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

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

2013-06-03

206

Material constraints for thin-film solar cells  

Microsoft Academic Search

Harnessing solar energy by using photovoltaic cells has the potential to become a major CO2-free energy source. Materials requirements for the solar cells based on four types of thin-film photovoltaics have been estimated and compared with global reserves, resources and annual refining. The use of solar cells based on Cd, Ga, Ge, In, Ru, Se and Te as a major

B. A Andersson; C Azar; J Holmberg; S Karlsson

1998-01-01

207

Determination of the solar cell panel installation angle  

Microsoft Academic Search

The output power of the solar cell panel is highly affected by the sunlight incident angle. The efficiency can be improved if the solar cell panel is properly installed with the optimum angle. The relationship between the sunlight incident angle and the sunlight radiation intensity on the solar cell panel surface is presented in this paper. Genetic algorithms with climatic

Yaow-Ming Chen; Hsu-Chin Wu

2001-01-01

208

Flexible thermal cycle test equipment for concentrator solar cells  

DOEpatents

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.

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

2012-06-19

209

A Photoelectrochemical Solar Cell: An Undergraduate Experiment.  

ERIC Educational Resources Information Center

|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…

Boudreau, Sharon M.; And Others

1983-01-01

210

Photon degradation effects in terrestrial solar cells  

Microsoft Academic Search

A certain type of photon degradation effect has been observed experimentally in n(+)\\/p solar cells. It is found that this effect is caused by a recombination center, the formation of which requires the simultaneous presence of a lattice defect and a silver atom or complex of atoms. The center is electrically active in its equilibrium state; the energy level of

V. G. Weizer; H. W. Brandhorst; J. D. Broder; R. E. Hart; J. H. Lamneck

1978-01-01

211

Screen printed boron emitters for solar cells  

Microsoft Academic Search

Screen printed (SP) boron emitters are presented as a useful option for the manufacturing of p-type emitters of solar cells. Details are provided on the diffusion process, including deposition, drying and firing steps, the latter performed in an infrared belt furnace. Besides their main dependences on the firing conditions, the sheet resistances and dopant profiles of the resulting emitters reveal

F. Recart; I. Freire; L. Pérez; R. Lago-Aurrekoetxea; J. C. Jimeno; G. Bueno

2007-01-01

212

The fatigue properties of solar cell interconnectors  

Microsoft Academic Search

The fatigue properties of varieties of silver plated molybdenum and silver mesh solar cell interconnectors were determined by deflection controlled cyclic tests at low temperature using a specially designed test unit. While the test conditions did not exactly simulate those experienced in service, the results allow comparisons to be made based on the fatigue properties of existing interconnectors and conclusions

R. B. Evans; S. Stevens

1978-01-01

213

Fatigue properties of solar cell interconnectors  

Microsoft Academic Search

A test rig was developed to evaluate the fatigue properties of molybdenum and silver mesh solar cell interconnectors at temperatures of -130 C and -170 C. The rig consists of an electromagnetic vibrator and a specimen clamping system and is operated using a closed loop system of control. The molybdenum interconnectors contain a complex loop to provide flexibility. The effect

R. B. Evans; S. Stevens; P. Campbell

1977-01-01

214

Fatigue Properties of Solar Cell Interconnectors.  

National Technical Information Service (NTIS)

A test rig was developed to evaluate the fatigue properties of molybdenum and silver mesh solar cell interconnectors at temperatures of -130 C and -170 C. The rig consists of an electromagnetic vibrator and a specimen clamping system and is operated using...

R. B. Evans S. Stevens P. Campbell

1977-01-01

215

A Bicontinuous Double Gyroid Hybrid Solar Cell  

Microsoft Academic Search

We report the first successful application of an ordered bicontinuous gyroid semiconducting network in a hybrid bulk heterojunction solar cell. The freestanding gyroid network is fabricated by electrochemical deposition into the 10 nm wide voided channels of a self-assembled, selectively degradable block copolymer film. The highly ordered pore structure is ideal for uniform infiltration of an organic hole transporting material,

Edward J. W. Crossland; Marleen Kamperman; Mihaela Nedelcu; Caterina Ducati; Ulrich Wiesner; Detlef-M. Smilgies; Gilman E. S. Toombes; Marc A. Hillmyer; Sabine Ludwigs; Ullrich Steiner; Henry J. Snaith

2009-01-01

216

Integral screen printed solar cells panel  

Microsoft Academic Search

This paper summarizes our activities in the field of process technologies for the fabrication of photovoltaic devices. The study is strongly focused on the integral screen printing technique for the fabrication of single crystal solar cells, using standard equipments available in our laboratory. The challenging aim of this survey is to attain encouraging results with very modest means. Knowing that

Y. Boukennous; B. Benyahia; M. R. Charif; A. Elamrani; M. F. Moussa

217

Phthalocyanine Blends Improve Bulk Heterojunction Solar Cells  

PubMed Central

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

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

2010-01-01

218

Development of high efficiency solar cells  

Microsoft Academic Search

Emphasis was on developing new polycrystal growth techniques, developing new analytical techniques to study grain boundaries, and fundamental studies of the physical mechanisms by which grain boundaries limit solar cell performance. Molecular beam epitaxy proved to be a very attractive technique for fundamental studies of both grain boundaries and unique device structures. Several high spatial resolution analytical techniques were developed

D. L. Miller; M. J. Cohen; J. S. Harris Jr.; J. J. Loferski; J. Ballantyne; T. Bhar; E. Stefanakos

1979-01-01

219

Solar-Cell Testing and Evaluation.  

National Technical Information Service (NTIS)

A two year study of the degradation effects in AlGaAs/GaAs solar cells is described. Illuminated current-voltage measurements were made during temperature and humidity cycling and time dependent degradation measurements were recorded. (ERA citation 07:061...

E. K. Stefanakos W. J. Collis

1982-01-01

220

Screen printed interdigitated back contact solar cell  

NASA Astrophysics Data System (ADS)

Interdigitated back contact solar cells are made by screen printing dopant materials onto the back surface of a semiconductor substrate in a pair of interdigitated patterns. These dopant materials are then diffused into the substrate to form junctions having configurations corresponding to these patterns. Contacts having configurations which match the patterns are then applied over the junctions.

Baraona, C. R.; Mazaris, G. A.; Chai, A. T.

1984-10-01

221

Microscopy for Graetzel Solar cells manufacturing  

Microsoft Academic Search

The Graetzel solar cells are devices composed by two transparent glass conductive surfaces, one nanocrystalline structure interfase of TiO 2 , where a dye is introduced. The manufacturing process includes tasks where microscopy is an important tool. For instance an intermediate task is make conductive a SiO2 glass that normally is non conductive, so it is necessary take into account

Héctor I. Olmos Castillo; Gerardo Zavala Guzmán

222

Transparent conductors for solar cell applications  

SciTech Connect

Non-stoichiometric and doped films of oxides of Sn, In, Cd, Zn and their alloys are highly transparent in the visible and also electrically conducting. The preparation and electro-optical properties of these films, and their applications in solar cells are reviewed.

Chopra, K.L.; Major, S.

1983-05-01

223

Defect analysis in polycrystalline silicon solar cells  

SciTech Connect

Localized bulk defects like diffusion length variations and structural defects like grain boundaries are analyzed in polycrystalline silicon solar cells using laser scanning and deep level transient spectroscopy techniques. The effect of hydrogen passivation on the role of grain boundaries has been studied.

Sastry, O.S.; Dutta, V.; Mukerjee, A.K.; Chopra, K.L.

1985-06-15

224

Nanostructured Solar Cells for High Efficiency Photovoltaics  

Microsoft Academic Search

The use of nanostructures in photovoltaics offers the potential for high efficiency by either using new physical mechanisms or by allowing solar cells which have efficiencies closer to their theoretical maximum, for example by tailoring material properties. At the same time, nanostructures have potentially low fabrication costs, moving to structures or materials which can be fabricated using chemically or biologically

Christiana B. Honsberg; Allen M. Barnett; Douglas Kirkpatrick

2006-01-01

225

Improved Thin-Film Solar Cells.  

National Technical Information Service (NTIS)

During this contract thin-film GaAs solar cells using semitransparent Pt layers as the barrier contact have been made and investigated to improve their photovoltaic characteristics. Studies of the GaAs film, grown by the close-spaced oxide transport proce...

D. M. Perkins W. L. Hui G. Noel E. F. Pasierb

1966-01-01

226

Photochemical oxidation and autoxidation of chlorophyll phytyl side chain in senescent phytoplanktonic cells: potential sources of several acyclic isoprenoid compounds in the marine environment.  

PubMed

Visible light-induced degradation of the chlorophyll phytyl side chain was studied in senescent cells of two phytoplanktonic strains (Skeletonema costatum and Thalassiosira weissflogii). Particular attention was paid to the induction of autoxidation processes on the phytyl chain and its photoproducts by photochemically produced hydroperoxides. The combination of photochemical oxidation and autoxidation reactions resulted in the production of several acyclic isoprenoid compounds that have been unambiguously identified by comparison of their retention times and mass spectra with those of appropriate standards. Various mechanisms are proposed to explain the formation of these oxidation products. These processes appear to be potential sources of numerous oxidized acyclic isoprenoids that previously have been detected in lacustrine and marine environments. Some oxidation products newly described or whose presence in natural samples was never reported in the literature were then sought in particulate matter, sediment, and microbial mat samples. The results obtained supported the significance of photochemical oxidation and autoxidation of phytoplanktonic chlorophyll phytyl side chain in the marine environment. PMID:12784864

Rontani, Jean-François; Rabourdin, Adélaïde; Marchand, Daphné; Aubert, Claude

2003-03-01

227

Direct-Write Contacts for Solar Cells  

SciTech Connect

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.

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

228

Photochemical Escape of C from Mars  

NASA Astrophysics Data System (ADS)

Atomic carbon may escape from the atmosphere of Mars by a number of non-thermal mechanisms, which may be photochemical or mechanical processes, such as sputtering. We present model calculations of the escape rate of C by the photochemical escape mechanisms, including dissociative recombination of CO+, photodissociation and photodissociative ionization of CO, electron impact dissociation and dissociative ionization of CO, and a few chemical reactions. Our background model is based on the MTGCM model of Bougher and co-workers, and the solar fluxes are from the solar flux model of Ayres. We find that the most important escape mechanism is dissociative recombination of CO+, but photodissociation may also make a signficant contribution if the mixing ratio of CO is larger at high solar activity than at low solar activity.

Fox, J. L.

1999-12-01

229

Photochemical Escape of C from Mars  

NASA Astrophysics Data System (ADS)

Atomic carbon may escape from the atmosphere of Mars by a number of non-thermal mechanisms, which may be photochemical or mechanical processes, such as sputtering. We present model calculations of the escape rate of C by the photochemical escape mechanisms, including dissociative recombination of CO^+, photodissociation and photodissociative ionization of CO, electron impact dissociation and dissociative ionization of CO, and a few chemical reactions. Our background model is based on the MTGCM model of Bougher and co-workers, and the solar fluxes are from the solar flux model of Ayres. We find that the most important escape mechanism is dissociative recombination of CO^+, but photodissociation may also make a signficant contribution if the mixing ratio of CO is larger at high solar activity than at low solar activity.

Fox, Jane L.

1999-10-01

230

Enhancing Solar Cell Efficiencies through 1-D Nanostructures  

NASA Astrophysics Data System (ADS)

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

Yu, Kehan; Chen, Junhong

2009-01-01

231

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

NASA Astrophysics Data System (ADS)

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

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

2012-10-01

232

High efficiency silicon MINP solar cells  

NASA Astrophysics Data System (ADS)

Investigations of high-efficiency MINP silicon solar cells are discussed. Emphasis is placed on cell characterization to develop a basic understanding of current-transport mechanisms which limit cell efficiency. Fabrication and characterization of cells based on 0.2 ohm-cm substrates, diffused emitters 150-200-nm deep, and with Mg MIS collector grids are discussed. A total-area AM1 efficiency of 16.8 percent has been achieved. Detailed analyses of photocurrent and current-loss mechanisms are presented and utilized to predict future directions of research.

Olsen, L. C.; Addis, F. W.; Miller, W. A.; Dunham, G.

233

Reverse bias degradation in dye solar cells  

NASA Astrophysics Data System (ADS)

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.

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

2012-09-01

234

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

PubMed

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

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

2012-10-04

235

Experimental study of variations of the solar spectrum of relevance to thin film solar cells  

Microsoft Academic Search

The influence of variations in the incident solar spectrum on solar cells is often neglected. This paper investigates the magnitude of this variation and its potential influence on the performance of thin film solar cells in a maritime climate. The investigation centres on the analysis of a large number of measurements carried out in Loughborough, UK, at 10min intervals over

R. Gottschalg; D. G. Infield; M. J. Kearney

2003-01-01

236

Modeling the Effects of Solar Cell Distribution on Optical Cross Section for Solar Panel Simulation.  

National Technical Information Service (NTIS)

The Air Force Research Laboratory (AFRL) Time-domain Analysis Simulation for Advanced Tracking (TASAT) was used to explore the variation of Optical Cross Section (OCS) with glint angle for a solar panel with different solar cell distribution statistics. S...

K. Feirstine L. Vaughn M. Duggin M. Klein

2012-01-01

237

18 percent efficient polycrystalline silicon solar cells  

NASA Astrophysics Data System (ADS)

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 addition of a phosphorous pretreatment step and modifications of a rear Al alloying step and cell processing temperatures. Surface texturing is identified as an important area requiring attention to obtain the highest possible efficiency. Laser texturing has given the best results to date for polycrystalline substrates. Results are described for a laser-textured, laser-grooved cell processing sequence with the potential to produce polycrystalline cells having efficiencies well above 18 percent.

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

238

Synergism between photochemical and ionizing radiation effects in MCF-7 cells in vitro  

NASA Astrophysics Data System (ADS)

Both PtCl4 (Rh-123)2 and PtCl4 (Nile Blue)2 interact positively in trimodality therapy including each drug, x-ray, and light (400 - 800 nm) in killing human mammary carcinoma cells (MCF-7) in vitro. The combination treatment results in more than additive killing as assessed by product of the surviving fractions and a significant reduction of the shoulder of the x-ray survival curve. Both of the drugs participate in photodynamic therapy (PDT) in drug and light dose dependent manner. The primary subcellular targets for the neutral platinum complexes were indicated to be the nuclear DNA as opposed to the mitochondria for Rh-123 or the lysosomes for Nile Blue. Because the nuclear DNA is also the primary target for ionizing radiation, drug plus light plus x-ray might cause supraadditive killing. Both PtCl4 (Rh-123)2 and PtCl4 (Nile Blue)2 have been reported to be relatively non-toxic in vivo compared to the anionic or cationic compounds currently being used in photodynamic therapy. Based on these results PtCl4 (Rh-123)2 and PtCl4 (Nile Blue)2 have the potential for use in photodynamic therapy and in trimodality therapy.

Ara, Gulshan; Herman, Terence S.; Varshney, Archana; Korbut, Timothy; Teicher, Beverly A.

1992-08-01

239

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

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

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

2011-10-19

240

Solar cell single measurement maximum power point tracking  

Microsoft Academic Search

It is possible to give a valuable estimation for an entire solar array IV curve, based only on a single working point (current and voltage) measurement, on panels of solar cells, when several of their parameters are known and environmental parameters also known. The estimations were performed using Matlab\\/Simulink and the simulation is based on the 10 parameter solar cell

Raul Rabinovici; Yotam B. Frechter

2010-01-01

241

High performance organic solar cells with interface engineering  

Microsoft Academic Search

Polymer solar cells are considered a promising candidate for renewable energy with low-cost and high volume production capability. The main focus of this dissertation is to investigate the several approaches for improving the efficiency of polymer solar cells. These approaches include understanding of the physics, operation mechanisms, materials and device engineering and optimization of fabrication processes. A typical polymer solar

Mi Hyae Park

2010-01-01

242

Recent advances in sensitized mesoscopic solar cells.  

PubMed

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

Grätzel, Michael

2009-11-17

243

Improved efficiency silicon solar cell module  

SciTech Connect

This paper describes a solar cell module efficiency of 22.3% independently measured at Sandia National Laboratories. This the highest ever confirmed efficiency for a photovoltaic module of this size achieved by cells made on any material. This 787-cm{sup 2} module used 40 large-area double-layer antireflection coated PERL (passivated emitter, rear locally-diffused) silicon cells of average efficiency of 23.1%. The double-layer coating, together with an improved cell structure and a shingled encapsulation technique, considerably contributed to this efficiency improvement. Also reported is an independently confirmed efficiency of 23.7% for a 21.60-cm{sup 2} cell of the type used in the module, the highest efficiency ever reported for a silicon cell of this size.

Zhao, J.; Wang, A.; Abbaspour-Sani, E.; Yun, F.; Green, M.A. [Univ. of New South Wales, Sydney (Australia). Photovoltaics Special Research Centre

1997-02-01

244

Design, synthesis, photochemical properties and cytotoxic activities of water-Soluble caged l-Leucyl- l-leucine methyl esters that control apoptosis of immune cells  

Microsoft Academic Search

l-Leucyl-l-leucine methyl esters (LeuLeuOMe) is a lysosomotropic agent that induces apoptosis of certain immune cells. Glucose-carrying 2-nitrobenzyl (2-NB) and 2-nitrophenethyl (2-NPE) caged LeuLeuOMe, 1a and b, were synthesized and their photochemical and immunological properties were studied. Caged glycine methyl esters (GlyOMe), 2a,b, were also prepared to examine the cytotoxic activity of the photolytic byproducts from 1a,b. All the caged compounds

Hironori Mizuta; Soichiro Watanabe; Yuji Sakurai; Keiko Nishiyama; Toshiaki Furuta; Yoshiro Kobayashi; Michiko Iwamura

2002-01-01

245

Nanostructured upconverters for improved solar cell performance  

NASA Astrophysics Data System (ADS)

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.

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

2013-09-01

246

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...

247

Research Profiling: Nano-enhanced, Thin-film Solar Cells  

Microsoft Academic Search

Nanotechnology-enhanced thin-film solar cells constitute one of the most promising solar energy solutions and an important currently emerging application of nanotechnology. This paper profiles the research patterns via \\

Ying Guo; Lu Huang; Alan L. Porter

248

Improved Solar Cells Testing Fixtures.  

National Technical Information Service (NTIS)

A rotating platform which can lock, connect and test the electrical parameters of two cells, locating them in the same position under the light beam, is described. Multi-filter spectral response equipment which operates in combination with the platform is...

G. Sala J. Aguilera J. C. Zamorano E. Sanchez A. M. Grass

1989-01-01

249

Chalcopyrite thin film solar cells by electrodeposition  

Microsoft Academic Search

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

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

250

Microcrystalline organic thin-film solar cells.  

PubMed

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

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

2013-08-13

251

Materials availability for thin film solar cells  

Microsoft Academic Search

Materials availability is one of the most important factors when we consider the mass-production of next generation photovoltaic devices. ``In (indium)'' is a vital element to produce high efficient thin film solar cells such as InP and CuIn(Ga)Se2 but its lifetime as a natural resource is suggested to be of order of 10~15 years. The lifetime of a specific natural

Yunosuke Makita

1997-01-01

252

Aluminum arsenide eutectic gallium arsenide solar cell  

Microsoft Academic Search

An improved gallium arsenide solar cell is provided by forming a P+ layer on top of a wafer of vertical PN junction eutectic gallium arsenide crystal by liquid phase epitaxial growth of P doped GaAs followed by liquid phase epitaxial growth at Al(x)AsGa(1-x) on the surface of the vertical PN junction substrate. The deposited GaAs layer with P dopant and

Rahilly

1976-01-01

253

Aluminum arsenide eutectic gallium arsenide solar cell  

Microsoft Academic Search

An improved gallium arsenide solar cell is provided by forming a P + layer on top of a wafer of plural vertical PN junction eutectic gallium arsenide crystal by liquid phase epitaxial growth of P doped GaAs followed by liquid phase epitaxial growth at Al\\/sub x\\/AsGa\\/sub l-x\\/ on the surface of the vertical PN junction substrate. The deposited GaAs layer

Rahilly

1978-01-01

254

Solar cell array with lightweight support structure  

Microsoft Academic Search

A panel comprising an aluminum honeycomb core and outer face skins of Kevlar, a bi-directional epoxy-reinforced polyparabenzamide fabric which is a thermal and electrical insulator adhering to the core and forming the opposite flat surfaces of the panel. Solar cells are glued directly to one face skin while a set of epoxy-reinforced carbon fiber stiffeners are glued to the other

Gounder

1983-01-01

255

Solar-hydrogen fuel-cell vehicles  

Microsoft Academic Search

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

Mark A. DeLuchi; Joan M. Ogden

1993-01-01

256

Efficient CIGS solar cells prepared by electrodeposition  

Microsoft Academic Search

Cu(In,Ga)Se\\/sub 2\\/\\/CdS\\/ZnO cells with efficiencies close to 19% have been obtained with films prepared by coevaporation of the elements. Electrodeposition has the potential to become a suitable method for large production of CIGS solar modules. In this paper, we present the results of an on going collaboration project, between CNRS-ENSCP, EDF (Electricite de France) and SUR (Saint Gobain Recheche) with

D. Guimard; N. Bodereau; J. Kurdi; J. F. Guillemoles; D. Lincot; P. P. Grand; M. BenFarrah; S. Taunier; O. Kerrec; P. Mogensen

2003-01-01

257

Health effects of solar cell component material.  

PubMed

Owing to the increasing interest being paid to the issue of the global environment, the production of solar cells has increased rapidly in recent years. Copper indium gallium diselenide (CIGS) is a new efficient thin film used in some types of solar cell. Indium is a constitutive element of CIGS thin-film solar cells. It was thought that indium compounds were not harmful until the beginning of the 1990s because there was little information regarding the adverse health effects on humans or animals arising from exposure to indium compounds. After the mid-1990s, data became available indicating that indium compounds can be toxic to animals. In animal studies, it has been clearly demonstrated that indium compounds cause pulmonary toxicity and that the dissolution of indium compounds in the lungs is considerably slow, as shown by repeated intratracheal instillations in experimental animals. Thus, it is necessary to pay much greater attention to human exposure to indium compounds, and precautions against possible exposure to indium compounds are paramount with regard to health management. PMID:23718969

Tanaka, Akiyo; Hirata, Miyuki

2013-01-01

258

Squaraine donor based organic solar cells  

NASA Astrophysics Data System (ADS)

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.

Wei, Guodan

259

High temperature-high current solar cells for thermophotovoltaic systems  

SciTech Connect

The conditions under which a photovoltaic cell operates in a thermophotovoltaic system are examined. The design of solar cells capable of operating under these conditions is then formulated and the efficiency of such cells is computed. It is shown that efficiencies in excess of 40% are possible in silicon p-n junction solar cells.

Neville, R.C.

1982-01-01

260

First space flight of InP solar cells  

Microsoft Academic Search

A large-scale, commercial process to produce high-efficiency diffused junction InP solar cells is developed. Proton irradiation effects on InP solar cells are also studied. Superior proton resistance of InP cells is confirmed by defect analysis. 1300 pieces of InP solar cells (2×1 cm2), with efficiencies of 16-17%, were used as the power source for the lunar orbiter of the Japanese

M. Yamaguchi; T. Hayashi; A. Ushirokawa; Y. Takahashi; M. Koubata; M. Hashimoto; S. Ikegami; H. Arai; T. Orii; H. Okazaki; T. Takamoto; M. Ura; M. Ohmori

1990-01-01

261

Saturation current in solar cells - An analysis  

NASA Astrophysics Data System (ADS)

An analysis of the saturation current in solar cells indicates that the factor A in the Shockley equation is material independent and has a constant value of 2.95 x 10 to the 5th A per sq cm of the cell. The saturation current, I(0), and a fundamental solid state parameter, the 0 K Debye temperature, are explicitly correlated on the basis of the work of Ravindra and Srivastava (1979). It is shown that dLnI(0)/dT increases with the energy gap at 0 K.

Ravindra, N. M.

1980-10-01

262

Variation of solar cell sensitivity and solar radiation on tilted surfaces  

Microsoft Academic Search

An empirical study was performed (1) to evaluate the validity of various insolation models used to compute solar radiation incident on tilted surfaces from global data measured on horizontal surfaces and (2) to determine the variation of solar cell sensitivity to solar radiation over a wide range of atmospheric condition. Evaluation of the insolation data indicates that the isotropic sky

T. M. Klucher

1978-01-01

263

Technical use of solar energy. Part 1. Thin films solar cells  

Microsoft Academic Search

Due to the potentialities of Cu2-xS-CdS thin film solar cells, several companies installed production lines for this type of solar cell. Besides investigations for further enhancing efficiency and long-term stability, for gaining data of physical and electronical parameters, and for improving the theoretical knowledge of the cell, materials and technologies are investigated which look promising for large-scale industrial production. Solar

W. Arndt; G. H. Bauer; H. U. Berger; W. H. Bloss; G. H. Hewig; F. Pfisterer; H. W. Schock

1983-01-01

264

Calculation of the Performance of Solar Cells With Spectral Down Shifters Using Realistic Outdoor Solar Spectra  

Microsoft Academic Search

Spectral down converters and shifters have been proposed as a good means to enhance the efficiency of underlying solar cells. In this paper, we focus on the simulation of the outdoor performance of solar cells with spectral down shifters, i.e., multicrystalline silicon solar cells with semiconductor nanocrystals as wavelength-shifting material. Daily and\\u000aannual performance of these devices can be simulated

W. G. J. H. M. van Sark

2007-01-01

265

Thin film polycrystalline silicon solar cells  

SciTech Connect

During the present quarter efficiency of heterostructure solar cells has been increased from 13 to 13.7% for single crystal and from 10.3 to 11.2% for polysilicon. For polysilicon the improvements can be attributed to reductions in grid-area coverage and in reflection losses and for single crystal to a combination of reduction in grid-area coverage and increase in fill factor. The heterostructure cells in both cases were IT0/n-Si solar cells. Degradation in Sn0/sub 2//n-Si solar cells can be greatly reduced to negligible proportions by proper encapsulation. The cells used in stability tests have an average initial efficiency of 11% which reduces to a value of about 10.5% after 6 months of exposure to sunlight and ambient conditions. This small degradation occurs within the first month, and the efficiency remains constant subsequently. The reduction in efficiency is due to a decrease in the open-circuit voltage only, while the short-circuit current and fill factor remain constant. The effects of grain-size on the Hall measurements in polysilicon have been analyzed and interpreted, with some modifications, using a model proposed by Bube. This modified model predicts that the measured effective Hall voltage is composed of components originating from the bulk and space-charge region. For materials with large grains, the carrier concentration is independent of the inter-grain boundary barrier, whereas the mobility is dependent on it. However, for small rains, both the carrier density and mobility depend on the barrier. These predictions are consistant with experimental results of mm-size Wacker polysilicon and ..mu..m-size NTD polysilicon.

Ghosh, A. K.; Feng, T.; Eustace, D. J.; Maruska, H. P.

1980-01-01

266

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

National Technical Information Service (NTIS)

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 encoun...

B. L. Sater

1992-01-01

267

Calibration of solar simulator for evaluation of dye-sensitized solar cells  

Microsoft Academic Search

The photo-to-electricity energy conversion efficiencies of ruthenium-dye-sensitized solar cells (DSC) are measured under a solar simulator. The error in conversion efficiencies was compared under a variety of spectral conditions. Measurements of the conversion efficiencies of DSC between a solar simulator and outdoor sunlight result in about 10% error. This error was seen when the spectral intensity of a xenon-lamp solar

Seigo Ito; Hiroshi Matsui; Ken-ichi Okada; Sei-ichi Kusano; Takayuki Kitamura; Yuji Wada; Shozo Yanagida

2004-01-01

268

Solar module having reflector between cells  

DOEpatents

A photovoltaic module comprising an array of electrically interconnected photovoltaic cells disposed in a planar and mutually spaced relationship between a light-transparent front cover member in sheet form and a back sheet structure is provided with a novel light-reflecting means disposed between adjacent cells for reflecting light falling in the areas between cells back toward said transparent cover member for further internal reflection onto the solar cells. The light-reflecting comprises a flexible plastic film that has been embossed so as to have a plurality of small V-shaped grooves in its front surface, and a thin light-reflecting coating on said front surface, the portions of said coating along the sides of said grooves forming light-reflecting facets, said grooves being formed so that said facets will reflect light impinging thereon back into said transparent cover sheet with an angle of incidence greater than the critical angle, whereby substantially all of the reflected light will be internally reflected from said cover sheet back to said solar modules, thereby increasing the current output of the module.

Kardauskas, Michael J. (Billerica, MA)

1999-01-01

269

Substrate Configuration Cadmium Telluride Solar Cells  

NASA Astrophysics Data System (ADS)

Cadmium telluride/cadmium sulfide substrate type thin-film solar cells were fabricated on 0.1 mm thick molybdenum and stainless steel substrates. The deposition method was radio frequency plasma sputtering in argon at pressures of 10 - 20 mTorr. The structure was: substrate/(ZnTe:N)/CdTe/CdS/TCO. The Transparent Conducting Oxide (TCO) was ITO or ZnO:Al. This is an inverted configuration compared to the conventional glass/TCO/CdS/CdTe/contact devices. Solar cells on Mo substrates exhibited up to 7.8(the highest value reported so far for this type of devices) and the cells on stainless steel or with ZnO:Al were about 3above 70shape at the red and blue edges of the spectrum show that there is less CdTe-CdS interdiffusion during the post-growth heat treatment compared to the conventional superstrate cells. This is attributed to the fully developed CdTe grains at the CdTe-CdS interface. Also, the current is limited at voltages above 0.8 V which indicates a back-diode effect at the metal-CdTe or CdS-TCO interface. Supported by the National Renewable Energy Laboratory.

Matulionis, Ilvydas

2002-03-01

270

Recent Advances in Sensitized Solar Cells  

NASA Astrophysics Data System (ADS)

Understanding the principal physical and chemical factors that govern or limit cell performance is critical for underpinning the development of next-generation sensitized solar cells. Recent studies of dye-sensitized solar cells (DSSCs) covering nanoporous (pore diameter <100 nm) one-dimensional TiO2 nanostructured arrays and molecular voltage enhancers are discussed. Films constructed of oriented one-dimensional nanostructures, such as nanotube arrays, which are aligned perpendicularly to the charge-collecting substrate, could potentially improve the charge-collection efficiency by promoting faster transport and/or slower recombination. The extent to which transport or recombination could be affected by an oriented architecture is expected to depend on the influence of other mechanistic factors, such as the density and location of defects, crystallinity, and film uniformity. Orientational disorder within the nanotube array could also influence the transport and recombination kinetics. Such architectural disorder in titanium dioxide films is shown to have a strong influence on the transport, recombination, and light-harvesting properties of DSSCs. The mechanism by which molecular adsorbents alter the photovoltage of DSSCs is dependent on the properties of the adsorbent. In principle, an adsorbent could affect the photovoltage by either altering the recombination rate of photoelectrons in TiO2 with oxidized redox species in the electrolyte or inducing band-edge movement. The net effect of altering the band positions and recombination kinetics can either improve or diminish cell performance. The mechanisms by which several molecular adsorbents increase the photovoltage of DSSCs are discussed.

Frank, Arthur J.

271

High efficiency, radiation-hard solar cells  

SciTech Connect

The direct gap of the In{sub 1-x}Ga{sub x}N alloy system extends continuously from InN (0.7 eV, in the near IR) to GaN (3.4 eV, in the mid-ultraviolet). This opens the intriguing possibility of using this single ternary alloy system in single or multi-junction (MJ) solar cells of the type used for space-based surveillance satellites. To evaluate the suitability of In{sub 1-x}Ga{sub x}N as a material for space applications, high quality thin films were grown with molecular beam epitaxy and extensive damage testing with electron, proton, and alpha particle radiation was performed. Using the room temperature photoluminescence intensity as a indirect measure of minority carrier lifetime, it is shown that In{sub 1-x}Ga{sub x}N retains its optoelectronic properties at radiation damage doses at least 2 orders of magnitude higher than the damage thresholds of the materials (GaAs and GaInP) currently used in high efficiency MJ cells. This indicates that the In{sub 1-x}Ga{sub x}N is well-suited for the future development of ultra radiation-hard optoelectronics. Critical issues affecting development of solar cells using this material system were addressed. The presence of an electron-rich surface layer in InN and In{sub 1-x}Ga{sub x}N (0 < x < 0.63) was investigated; it was shown that this is a less significant effect at large x. Evidence of p-type activity below the surface in Mg-doped InN was obtained; this is a significant step toward achieving photovoltaic action and, ultimately, a solar cell using this material.

Ager III, J.W.; Walukiewicz, W.

2004-10-22

272

Solar-QBO interaction and its impact on stratospheric ozone in a zonally averaged photochemical transport model of the middle atmosphere  

Microsoft Academic Search

We investigate the solar cycle modulation of the quasi-biennial oscillation (QBO) in stratospheric zonal winds and its impact on stratospheric ozone with an updated version of the zonally averaged CHEM2D middle atmosphere model. We find that the duration of the westerly QBO phase at solar maximum is 3 months shorter than at solar minimum, a more robust result than in

J. P. McCormack; D. E. Siskind; L. L. Hood

2007-01-01

273

POSS® Coatings as Replacements for Solar Cell Cover Glasses  

Microsoft Academic Search

Presently, solar cells are covered with Ce-doped microsheet cover glasses that are attached with Dow Corning DC 93500 silicone adhesive. This general approach has been used from the beginning of space exploration, however, it is expensive and time consuming. Furthermore, as the voltage of solar arrays increases, significant arcing has occurred in solar arrays, leading to loss of satellite power.

Henry Brandhorst; Tamara Isaacs-Smith; Brian Wells; Joseph D. Lichtenhan; Bruce X. Fu

2006-01-01

274

Recent progress of amorphous silicon solar cell technology in Japan  

Microsoft Academic Search

The current state of the art in Japanese activities in amorphous silicon solar cell R&D is reviewed. First, a change of the organization in the Sunshine Project is introduced. Second, some novel approaches and key technologies to improve solar cell efficiency with stabilized performance with amorphous materials such as a-SiC:H, ?c-SiC:H, a-SiGe:H, and their heterojunction and stacked solar cells are

Yoshihiro HAMAKAWA

1991-01-01

275

The CdTe Thin Film Solar Cell - AN Overview  

Microsoft Academic Search

The basic physical aspects of the CdTe-thin film solar cell in its various embodiments are reviewed. Deposition techniques are briefly described, results of present pilot-line production efforts and the future potential are discussed, which make the CdTe thin film solar cell a promising candidate for low cost and well-above 10% module-efficiency. A detailed costing model for thin film solar cells

Dieter Bonnet

1992-01-01

276

DOE\\/NREL fundamental and exploratory research into solar cells  

Microsoft Academic Search

The U.S. Department of Energy\\/National Renewable Energy Laboratory supports fundamental and exploratory research into solar cells. The purpose of the following set of research projects is twofold: (1) to provide fundamental experimental and theoretical foundations to existing photovoltaic (PV)\\/solar cell technologies, and (2) to explore whole new possibilities in PV\\/solar cell technologies, however revolutionary or nonconventional they might be. As

Richard Matson; Robert McConnell

2002-01-01

277

Metamorphic and Lattice-Matched Solar Cells Under Concentration  

Microsoft Academic Search

Metamorphic III-V semiconductor materials offer access to bandgaps that span key portions of the solar spectrum, enabling new bandgap combinations in multijunction solar cells, and increasing both theoretical and practical efficiency limits for terrestrial concentrator cells. Experimental results are given for the quantum efficiency of metamorphic GaInAs solar cells with bandgap from 1.1 to 1.4 eV, and for metamorphic GaInP

R. R. King; D. C. Law; K. M. Edmondson; C. M. Fetzer; R. A. Sherif; G. S. Kinsey; D. D. Krut; H. L. Cotal; N. H. Karam

2006-01-01

278

Solar cell fabrication studies pertinent to developing countries  

SciTech Connect

The question of photovoltaics among the many approaches to the energy problem as being of relevance in the Third World countries is discussed. Based on these studies, which involved the physics of solar cells, various solar cell configurations, the materials for their fabrication and their fabrication sequences, it was concluded that silicon homojunction solar cells are best suited to the present needs and environment of, and suitable for development in the Third World. The cadmium sulphide-cuprous sulphide solar cell could be considered as a viable future candidate. Attendant with the adoption of photovoltaics as electric energy supply, is the problem of technology transfer and development. Towards that goal, laboratory studies were carried out on the fabrication of solar cells using very simple fabrication sequences and materials to demonstrate the tolerable efficiencies are achievable by their use. To demonstrate how basic research could benefit solar cell fabrication, a number of experiments were undertaken; such as varying fabrication sequences and materials, finding their radiation tolerance, and carrying out Deep Level Transient Spectroscopy (DLTS) studies, in an attempt to understand some of the fabrication and environmental factors which limit solar cell performance. It was found that subjecting wafers to preheat treatments does not improve solar cell performance, but rather reduces solar cell radiation tolerance. Also P-type substrate solar cells were found to be more radiation resistant than N-type substrate solar cells. The Deep Level Transient Spectroscopy results showed that carbon and oxygen, as one would expect, are chief contaminants of the silicon wafers that were used in the fabrication of the solar cells.

Prah, J.H.

1983-01-01

279

New generation of space batteries--GaAs solar cells  

SciTech Connect

This paper describes a new generation of space power sources, GaAs solar cells, and the status of their development inside China and abroad. In conjunction with this, on the basis of unique properties associated with GaAs solar cells, it points out the direction of development, clarifies the value of key space applications, and, finally, forecasts the application prospects for GaAs solar cells.

Zhang, Z.; Shi, W.

1995-05-15

280

Polymer\\/Metal Oxide Nanocrystals Hybrid Solar Cells  

Microsoft Academic Search

In this paper, we present two different types of polymer\\/metal oxide nanocrystals hybrid photovoltaics. One is the poly(3-hexylthiophene) (P3HT)\\/TiO2 nanorods hybrid bulk heterojunction (BHJ) solar cell and the other is a nanostructured ZnO\\/P3HT hybrid solar cell. In a BHJ hybrid solar cell, the dispersed semiconducting nanocrystals lead to an increased interface area between polymer and nanocrystals, which can assist charge

Shao-Sian Li; Yun-Yue Lin; Wei-Fang Su; Chun-Wei Chen

2010-01-01

281

Multijunction Solar Cell Technology for Mars Surface Applications  

Microsoft Academic Search

Solar cells used for Mars surface applications have been commercial space qualified AMO optimized devices. Due to the Martian atmosphere, these cells are not optimized for the Mars surface and as a result operate at a reduced efficiency. A multi-year program, MOST (Mars Optimized Solar Cell Technology), managed by JPL Science Mission Directorate (SMD) and funded by NASA Code S,

Paul M. Stella; Nick Mardesich; Richard C. Ewell; Robert L. Mueller; Scott Endicter; Daniel Aiken; Kenneth Edmondson; Chris Fetzer

2006-01-01

282

Solar energy powered microbial fuel cell with a reversible bioelectrode  

Microsoft Academic Search

The solar energy powered microbial fuel cell is an emerging technology for electricity generation via electrochemically active microorganisms fueled by solar energy via in situ photosynthesized metabolites from algae, cyanobacteria, or living higher plants. A general problem with microbial fuel cells is the pH membrane gradient which reduces cell voltage and power output. This problem is caused by acid production

David P. B. T. B. Strik; Hubertus V. M. Hamelers; Cees J. N. Buisman

2010-01-01

283

A microprocessor-based instrument for automatic solar cell characterization  

Microsoft Academic Search

A system which digitally records solar cell performance parameters is discussed and the design of a microcomputer based measurement system for solar cells is described. The key parameter is the current-voltage characteristic, assayed by sweeping the bias voltage to vary the cell output voltage from zero to the open circuit value at a load resistance which is varied to values

G. C. Cardinali; E. Faldella

1982-01-01

284

Characterization of production GaAs solar cells for space  

SciTech Connect

The electrical performance of GaAs solar cells was characterized as a function of irradiation with protons and electrons with the underlying goal of producing solar cells suitable for use in space. Proton energies used varied between 50 keV and 10 MeV, and damage coefficients were derived for liquid phase epitaxy GaAs solar cells. Electron energies varied between 0.7 and 2.4 MeV. Cells from recent production runs were characterized as a function of electron and proton irradiation. These same cells were also characterized as a function of solar intensity and operating temperature, both before and after the electron irradiations. The long term stability of GaAs cells during photon exposure was examined. Some cells were found to degrade with photon exposure and some did not. Calibration standards were made for GaAs/Ge solar cells by flight on a high altitude balloon.

Anspaugh, B.E.

1988-12-01

285

Consciousness can reduce the voltage of the output signal of solar cell  

Microsoft Academic Search

When the sun's light radiate on the solar cell, the solar cell can produce the output signal as the photocurrent. We use the Data Acquisition Modules to record the voltage of the output signals. The v1 is voltage of the output signal of solar cell1; The v2 is the one of solar cell2. And these two solar cells stay side

Dayong Cao

2010-01-01

286

Recyclable organic solar cells on cellulose nanocrystal substrates  

PubMed Central

Solar energy is potentially the largest source of renewable energy at our disposal, but significant advances are required to make photovoltaic technologies economically viable and, from a life-cycle perspective, environmentally friendly, and consequently scalable. Cellulose nanomaterials are emerging high-value nanoparticles extracted from plants that are abundant, renewable, and sustainable. Here, we report on the first demonstration of efficient polymer solar cells fabricated on optically transparent cellulose nanocrystal (CNC) substrates. The solar cells fabricated on the CNC substrates display good rectification in the dark and reach a power conversion efficiency of 2.7%. In addition, we demonstrate that these solar cells can be easily separated and recycled into their major components using low-energy processes at room temperature, opening the door for a truly recyclable solar cell technology. Efficient and easily recyclable organic solar cells on CNC substrates are expected to be an attractive technology for sustainable, scalable, and environmentally-friendly energy production.

Zhou, Yinhua; Fuentes-Hernandez, Canek; Khan, Talha M.; Liu, Jen-Chieh; Hsu, James; Shim, Jae Won; Dindar, Amir; Youngblood, Jeffrey P.; Moon, Robert J.; Kippelen, Bernard

2013-01-01

287

Direct Write Contacts for Solar Cells  

SciTech Connect

Ag, Cu, and Ni metallizations were inkjet-printed with near-vacuum deposition quality. The approach developed can be easily extended to other conductors such as Pt, Pd, and Au. 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 the silicon nitride antireflective layer at 850 C resulting in 8%-efficient cells. Next-generation multicomponent inks (including etching agents) have also been developed with improved fire-through contacts leading to higher cell efficiencies. PEDOT-PSS polymer-based conductors were inkjet-printed with conductivity as good or better than that of spin-coated films.

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

2005-02-01

288

Elongated nanostructures for radial junction solar cells.  

PubMed

In solar cell technology, the current trend is to thin down the active absorber layer. The main advantage of a thinner absorber is primarily the reduced consumption of material and energy during production. For thin film silicon (Si) technology, thinning down the absorber layer is of particular interest since both the device throughput of vacuum deposition systems and the stability of the devices are significantly enhanced. These features lead to lower cost per installed watt peak for solar cells, provided that the (stabilized) efficiency is the same as for thicker devices. However, merely thinning down inevitably leads to a reduced light absorption. Therefore, advanced light trapping schemes are crucial to increase the light path length. The use of elongated nanostructures is a promising method for advanced light trapping. The enhanced optical performance originates from orthogonalization of the light's travel path with respect to the direction of carrier collection due to the radial junction, an improved anti-reflection effect thanks to the three-dimensional geometric configuration and the multiple scattering between individual nanostructures. These advantages potentially allow for high efficiency at a significantly reduced quantity and even at a reduced material quality, of the semiconductor material. In this article, several types of elongated nanostructures with the high potential to improve the device performance are reviewed. First, we briefly introduce the conventional solar cells with emphasis on thin film technology, following the most commonly used fabrication techniques for creating nanostructures with a high aspect ratio. Subsequently, several representative applications of elongated nanostructures, such as Si nanowires in realistic photovoltaic (PV) devices, are reviewed. Finally, the scientific challenges and an outlook for nanostructured PV devices are presented. PMID:24088584

Kuang, Yinghuan; Vece, Marcel Di; Rath, Jatindra K; Dijk, Lourens van; Schropp, Ruud E I

2013-10-03

289

Elongated nanostructures for radial junction solar cells  

NASA Astrophysics Data System (ADS)

In solar cell technology, the current trend is to thin down the active absorber layer. The main advantage of a thinner absorber is primarily the reduced consumption of material and energy during production. For thin film silicon (Si) technology, thinning down the absorber layer is of particular interest since both the device throughput of vacuum deposition systems and the stability of the devices are significantly enhanced. These features lead to lower cost per installed watt peak for solar cells, provided that the (stabilized) efficiency is the same as for thicker devices. However, merely thinning down inevitably leads to a reduced light absorption. Therefore, advanced light trapping schemes are crucial to increase the light path length. The use of elongated nanostructures is a promising method for advanced light trapping. The enhanced optical performance originates from orthogonalization of the light's travel path with respect to the direction of carrier collection due to the radial junction, an improved anti-reflection effect thanks to the three-dimensional geometric configuration and the multiple scattering between individual nanostructures. These advantages potentially allow for high efficiency at a significantly reduced quantity and even at a reduced material quality, of the semiconductor material. In this article, several types of elongated nanostructures with the high potential to improve the device performance are reviewed. First, we briefly introduce the conventional solar cells with emphasis on thin film technology, following the most commonly used fabrication techniques for creating nanostructures with a high aspect ratio. Subsequently, several representative applications of elongated nanostructures, such as Si nanowires in realistic photovoltaic (PV) devices, are reviewed. Finally, the scientific challenges and an outlook for nanostructured PV devices are presented.

Kuang, Yinghuan; Di Vece, Marcel; Rath, Jatindra K.; van Dijk, Lourens; Schropp, Ruud E. I.

2013-10-01

290

Photochemical Energy Conversion.  

ERIC Educational Resources Information Center

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)

Batschelet, William H.; George, Arnold

1986-01-01

291

Photochemical Reactivity of Perchloroethylene.  

National Technical Information Service (NTIS)

Perchloroethylene (PCE), a solvent used in dry cleaning, has been suspected of contributing significantly to photochemical ozone/oxidant (O3/Ox) problems in urban atmospheres. Past evidence, however, was neither complete nor consistent. To interpret more ...

B. Dimitriades B. W. Gay R. R. Arnts R. L. Seila

1983-01-01

292

aC:H absorber layer for solar cells matched to solar spectrum  

Microsoft Academic Search

An a-C:H-based absorber layer for photovoltaic application was fabricated by a DC PECVD. The stepped voltage biasing of the deposition process makes it possible to tailor the bandgap of the manufactured layers and match them to the solar spectrum. Such system can be used as intrinsic layer in p–i–n solar cells as well as in converter solar cells.

S. S. Tinchev; P. I. Nikolova; J. T. Dyulgerska; G. Danev; Tz. Babeva

2005-01-01

293

High-temperature solar cell for concentrated solar-power hybrid systems  

NASA Astrophysics Data System (ADS)

A high-temperature solar cell is proposed that harvests solar energy at elevated temperatures. Carrier separation is achieved by selective contacts that preferentially extract electrons or holes. The theoretical conversion efficiency of the proposed device is 38.6% at 600 K and an incident solar radiation concentration of 1000. The waste heat of this cell could be used by a secondary thermal converter boosting the total efficiency of the hybrid system above 55%.

Yang, Yang; Yang, Wenzheng; Tang, Weidong; Sun, Chuandong

2013-08-01

294

Thin-film cadmium telluride solar cells  

NASA Astrophysics Data System (ADS)

This is the final technical progress report of a research program entitled Thin-Film Cadmium Telluride Solar Cells. The major objective was to demonstrate chemical vapor deposition (CVD)-grown CdTe devices with a photovoltaic efficiency of at least 10%. The work included: (1) CVD and characterization of p-CdTe films of controlled resistivity; (2) deposition and characterization of heterojunction partners; (3) surface passivation of CdTe; and (4) preparation and characterization of thin-film solar cells. The CVD of p-CdTe was optimized with emphasis on resistivity control through nonstoichiometry and extrinsic doping. Both carbon and oxygen were identified as acceptors. The use of thermal oxidation for surface passivation of CdTe was investigated using capacitance-voltage measurement. Device-quality thermal oxide can be prepared by hydrogen annealing of CdTe before oxidation. Deposition and characterization of CdS, CdO, and ZnO:In were also carried out. The best thin-film cell to date had a conversion efficiency near 9%.

1986-09-01

295

Computer modeling of high intensity solar cells  

NASA Astrophysics Data System (ADS)

The purpose of this program is to provide general analytic support to Sandia National Laboratories' effort to develop high efficiency, high concentration solar cells. This report covers work performed between November 5, 1984, and December 31, 1985, and includes reprints of three papers presented at the 18th IEEE Photovoltaic Specialists' Conference. In the first paper, the factors that presently prevent achieving the predicted theoretical efficiencies (in excess of 30% at concentration) are examined. It is demonstrated, by two-dimensional computer simulations, that these efficiencies might be obtained by improved light trapping techniques and by fabrication of low resistance heteroface contacts. The second paper examines the Rose-Weaver lifetime and surface recombination velocity measurement technique. It is shown that the very small uncertainties in the measured quantities lead to large uncertainties in the computed lifetime and surface recombination velocity. This leads to radically different interpretations of how the recombination is distributed throughout the device, and therefore limits the usefulness of the measurement technique. Design options and constraints of GaAs concentrator cells are examined in the third paper. The effectiveness of various design options is assessed. It is shown that although such design options are of little use in increasing the efficiency of heteroface cells, they can improve the efficiency of shallow junction cells so that it is comparable to that of heteroface cells, In addition, documentation describing the use of both the one- and two-dimensional silicon codes, SCAP1D and SCAP2D, as well as the one-dimensional AlGaAs solar cell simulation code is included.

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

1987-01-01

296

Cable interconnections for solar cell modules  

SciTech Connect

This patent describes a photovoltaic solar cell device having a rear wall and a conductive terminal strip protruding from the rear wall and having a hole therein, a member made of an insulating material secured to the rear wall, the member having an aperture and being positioned so that the hole in the terminal strip extends across the aperture, and a nut capturing the strip to the member so as to provide an electrical connection with the strip, the nut having a threaded hole accessible through the aperture to receive a threaded hole accessible through the aperture to receive a threaded fastener for securing the strip to an electrical cable.

Tronstrom, E.; Norbedo, A.J.

1992-05-05

297

Heteroepitaxially grown InP solar cells  

Microsoft Academic Search

The properties of InP solar cells, processed by OMCVD on silicon substrates with an intermediate GaAs layer (InP\\/GaAs\\/Si) and on GaAs substrates (InP\\/GaAs), were determined before and after irradiation with 10-MeV protons. The preirradiation transport properties were found to be influenced largely by dislocations occurring at the InP-GaAs interface. A carrier removal rate of 1.8×103 cm-1 was observed after irradiation

I. Weinberg; C. K. Swartz; D. J. Brinker; D. M. Wilt

1990-01-01

298

Dye for dye-sensitized solar cell and dye-sensitized solar cell including the same  

US Patent & Trademark Office Database

A dye for a dye-sensitized solar cell according to embodiments of the present invention includes a compound having a silane group. The dye according to embodiments of the present invention may be used in a light absorption layer to improve photovoltaic efficiency and increase open-circuit voltage.

2011-08-02

299

Chemical “light meters” for photochemical and photobiological studies  

Microsoft Academic Search

.  Nitrate and nitrite solar actinometers or chemical ‘light meters’ were used to quantify light doses in photochemical and photobiological\\u000a experiments involving dimethylsulfide (DMS) and dimethylsulfoniopropionate (DMSP) cycling. Light doses were calculated based\\u000a on the photochemical production of salicylic acid (SA) from benzoic acid in these actinometers, with SA quantified by either\\u000a spectrofluorometry or high performance liquid chromatography. Nitrate and nitrite

David J. Kieber; Dierdre A. Toole; Joseph J. Jankowski; Ronald P. Kiene; George R. Westby; Daniela A. del Valle; Doris Slezak

2007-01-01

300

Solar energy from spinach and toothpaste: fabrication of a solar cell in schools  

NASA Astrophysics Data System (ADS)

We will show how pupils can make a solar cell with spinach, toothpaste and a few other items found in any school laboratory. This device is called a Graetzel cell, and could trigger off a revolution in photovoltaic technology.

Siemsen, F.; Bunk, A.; Fischer, K.; Korneck, F.; Engel, H.; Roux, D.

1998-01-01

301

Flexible solar cells based on cadmium sulfide and telluride  

SciTech Connect

Output parameters and diode characteristics under illumination of flexible thin-film solar cells ITO/CdS/CdTe/Cu/Au formed on polyimide films by vacuum methods are studied. Using mathematical modeling of the effect of diode characteristics under illumination on the efficiency, the physicothechnical parameters of such structures are optimized. This made it possible to obtain laboratory samples of flexible solar cells based on cadmium sulfide and telluride with an efficiency of 11.4%. Solar modules with an efficiency of 4.5% based on the developed flexible solar cells are formed for the first time.

Khrypunov, G. S., E-mail: khrip@ukr.net; Chernykh, E. P.; Kovtun, N. A. [National Technical University 'Kharkov Polytehcnical Institute' (Ukraine); Belonogov, E. K. [Voronezh State Technical University (Russian Federation)], E-mail: belonogov@phys.vorstu

2009-08-15

302

Energy converting material for solar cell application  

NASA Astrophysics Data System (ADS)

In this paper, we discuss the concept of an efficient infrared upconverting phosphor as an energy converting material that could potentially improve the efficiency of Si solar cells in bifacial configuration. Basic spectroscopic studies of Yb and Er-doped La2O2S phosphor was reported with particular attention to its upconversion properties under 1550 nm excitation. Different concentrations of phosphors were synthesized by solid state flux fusion method. The phosphor powders were well crystallized in a hexagonal shape with an average size 300-400 nm. The most efficient upconverting sample (1%Yb: 9% Er doped La2O2S) was also studied under the illumination with infrared (IR) broad band spectrum above 1000 nm. Our measurements show that even with an excitation power density of 0.159 W/cm2 using a tungsten halogen lamp the material shows efficient upconversion corroborating the fact that the present phosphors could be potential candidates for improving the efficiency of the present Si solar cells.

Pokhrel, Madhab; Kumar, G. A.; Sardar, Dhiraj K.

2012-02-01

303

Device modeling for organic solar cells  

NASA Astrophysics Data System (ADS)

Organic solar cells (OSCs) are expected to play an important role in addressing our future energy needs due to their low cost and low processing requirements compared to inorganic solar cells (ISCs). However the efficiency of OSCs is still too low in comparison with ISCs for widespread applications. The biggest loss of quantum efficiency (QE) in OSCs is due to the limited free carrier generation occurring at the donor-acceptor (D-A) interface. Excitons (bound electron-hole pairs) are generated in the bulk by photo-absorption, but only a portion of them reach the D-A interface where they can dissociate into free charge carriers. Therefore, better understanding and control of exciton diffusion, free carrier generation and recombination are critical in order to improve QE for OSCs. To elucidate the physics of OSCs and aid in experimental studies, we developed a drift-diffusion model to describe the dynamics of excitons and free charge carriers. Our model predicts the performance of OSC devices by calculating their QE and current-voltage curves (I-V), as well as many other important physical quantities, such as the internal electric field, and the concentration and flux of excitons and free carriers. The effect of exciton and free carrier mobility, device temperature, and layer thickness, will be discussed. Furthermore, the exciton dissociation mechanism widely described by Onsager's model, will be investigated in detail.

Huang, Lunmei; Krasny, Robert; Renshaw, Kyle; Forrest, Stephen

2012-02-01

304

Layer Transferred Graphene for Solar Cell Applications  

NASA Astrophysics Data System (ADS)

Indium tin oxide (ITO) used commonly as a transparent electrode has proven to be unfavorable for the eventual commercialization of organic photovoltaic devices. We have investigated graphene grown on copper by CVD and transferred to arbitrary substrates as a possible replacement for ITO. Graphene-covered copper foils (Alfa Aesar) were first coated in photoresist (Shipley 1805) and the copper was removed with a ferric chloride based etchant. After cleaning in water the photoresist and graphene was transferred to the substrate of choice and the photoresist was removed with acetone. The transferred graphene were found to show a Hall mobility higher than 2000 cm^2/Vs at room temperatures and optical absorbance of 3.2% at 550nm and 2.5% at 900nm. We used scanning Raman spectroscopy to characterize the thickness of the graphene and found that 90+% of layer transferred material is single layer graphene. The remainder was found to consist of clusters of bi- or multi-layer graphene of a typical size ranging from 0.5 to 2 ?m. We fabricated organic hybrid solar cells utilizing this material as a transparent electrode. Results including a comparison between graphene and ITO devices fabricated using the same procedure and efforts to improve the efficiency of such graphene hybrid solar cells will be presented. Work supported in part by NSF.

Myers, Ronald; Wang, Zhibing; Liu, Ying; Robinson, Joshua; Todd, Aaron; Xu, Jian

2010-03-01

305

Novel solar cells in a wire format.  

PubMed

Photovoltaic devices in a wire format have recently attracted increasing attention as, compared with the conventional planar structure, they show unique and promising advantages. For instance, they are light-weight and can be easily woven into clothes or integrated into other structures, which enable applications in electronic textiles and various complex devices. In this tutorial review, the recent advancement in photovoltaic wires including both dye-sensitized and polymer solar cells are described. Two main architectures based on a single core-sheath fiber and twisted fibers are carefully illustrated with an emphasis on the comparison of various substrates which have been focused in past development. The current challenge including low energy conversion efficiency and low stability and future direction of the wire-shaped cell have been finally summarized. PMID:23467786

Chen, Tao; Qiu, Longbin; Yang, Zhibin; Peng, Huisheng

2013-06-21

306

Photoelectrochemical Cell With Nondissolving Anode: New cell may be an economical alternative to silicon solar cell.  

National Technical Information Service (NTIS)

This citation summarizes a one-page announcement of technology available for utilization. An improved electrolytic photovoltaic cell converts solar energy to electricity without electrode decomposition. Cell efficiencies up to 15 percent have been measure...

1982-01-01

307

Recent Progress in Inorganic Solar Cells Using Quantum Structures  

Microsoft Academic Search

Thermalization of photogenerated carriers in bulk materials is the main bottleneck for the conversion efficiency of conventional inorganic solar cells. Furthermore, despite extensive research, the achieved conversion efficiency is nearly saturated during the last decade. Therefore, new device concepts to break through the efficiency barrier are highly requested. Nanotechnologies are the building blocks for next-generation solar cells, because low-dimensional quantum

Seung Y. Myong

2007-01-01

308

An investigation of mismatch losses in solar photovoltaic cell networks  

Microsoft Academic Search

Solar photovoltaic (PV) arrays in field conditions deliver lower power than the array rating. In this paper, the sensitivity of solar cell parameters in the variation of available power from the array is investigated. The parameters characteristic of aging and fresh cells used in prototype field systems have been used for computation of reduction in the available power. It is

N. D. Kaushika; Anil K. Rai

2007-01-01

309

Development of Novel II-VI Solar Cells.  

National Technical Information Service (NTIS)

The epitaxial growth of novel II-VI solar cell structures was investigated. In Phase I, the metal organic chemical vapor deposition (MOCVD) process parameters and associated growth chemistries for an epitaxial p-i-n, ZnTe/CdTe/GaAs, solar cell structure w...

G. S. Tompa

1990-01-01

310

Review Stability\\/degradation of polymer solar cells  

Microsoft Academic Search

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

Mikkel Jørgensen; Kion Norrman; Frederik C. Krebs

2008-01-01

311

Mercury cadmium telluride solar cell with 10. 6% efficiency  

SciTech Connect

Cd-rich mercury cadmium telluride (MCT) is a promising material for thin-film solar cell applications. In this letter we present data on the deposition of MCT films by a simple electroplating technique and report on the highest efficiency polycrystalline MCT thin-film solar cell to date, which has an efficiency of 10.6% under AM1.5 illumination.

Basol, B.M.; Tseng, E.S.

1986-04-07

312

CRADA Final Report: Process development for hybrid solar cells  

SciTech Connect

TCF funding of a CRADA between LBNL and RSLE leveraged RSLE's original $1M investment in LBNL research and led to development of a solar cell fabrication process that will bring the high efficiency, high voltage hybrid tandem solar cell closer to commercialization. RSLE has already built a pilot line at its Phoenix, Arizona site.

Ager, Joel W

2011-02-14

313

Electrical and optical characteristics of silicon nanocrystal solar cells  

Microsoft Academic Search

We investigated the relationship between the absorption in silicon nanocrystals (Si NCs) and the photocurrent of Si NC solar cells. Here, the absorption of Si NCs in the blue and green light regions was enhanced by up to 14 times compared to bulk Si. In addition, the photocurrent in Si NC solar cells was found to originate from absorption in

Sang-Kyun Kim; Chang-Hee Cho; Baek-Hyun Kim; Seong-Ju Park; Jae Won Lee

2009-01-01

314

Simulation studies on heterojunction and HIT solar cells  

NASA Astrophysics Data System (ADS)

Heterojunction solar cells have shown a promising comparable efficiency with the advantage of lower fabrication cost compared to the crystalline solar cells. In this paper, an attempt has been made to simulate the heterojunction structure and HIT structure using AMPS-1D software by applying various approaches. The simulation parameters of these structures are varied for cell efficiency, quantum efficiency, charge carrier concentration and temperature stability to achieve higher efficiency. The final solar cell parameters have been achieved about 20% for heterojunction and 23% for HIT cells. The effects on intrinsic and extrinsic characteristics of doped layers are discussed for these efficiencies.

Patel, Kamlesh; Panwar, O. S.; Bisht, Atul; Sreekumar, C.; Kumar, Sushil; Rauthan, C. M. S.

2012-10-01

315

A PHOTOCHEMICAL BOX MODEL FOR URBAN AIR QUALITY SIMULATION  

EPA Science Inventory

A simple 'box-approach' to air quality simulation modeling has been developed in conjunction with a newly formulated photochemical kinetic mechanism to produce an easily applied Photochemical Box Model (PBM). This approach represents an urban area as a single cell 20 km in both l...

316

Interim Report on Interdigitated Back-Contact Solar Cells.  

National Technical Information Service (NTIS)

The purpose of the work reported is to design, fabricate, test, and deliver silicon interdigitated back contact solar cells designed to operate at high sunlight intensity. A brief description of the Interdigitated Back Contact (IBC) cell is presented and ...

R. J. Schwartz

1978-01-01

317

How Porosity Modifies the Photovoltaic Effect in Nanocrystalline Solar Cells  

SciTech Connect

The porosity of the nanocrystalline semiconductor affects many aspects of the photoconversion process in dye-sensitzed solar cells, thus distinguishing them mechanistically from conventional photovoltaic and photoelectro-chemical cells. We discuss several examples from our recent work.

Gregg, B. A.; Pichot, F.

2000-01-01

318

Exploiting Nanocarbons in Dye-Sensitized Solar Cells.  

PubMed

Fullerenes, carbon nanotubes, nanodiamond, and graphene find various applications in the development of solar cells, including dye sensitized solar cells. Nanocarbons can be used as (1) active light-absorbing component, (2) current collector, (3) photoanode additive, or (4) counter electrode. Graphene-based materials have attracted considerable interest for catalytic counter electrodes, particularly in state-of-the-art dye sensitized solar cells with Co-mediators. The understanding of electrochemical charge-transfer at carbon surfaces is key to optimization of these solar cells, but the electrocatalysis on carbon surfaces is still a subject of conflicting debate. Due to the rich palette of problems at the interface of nanocarbons and photovoltaics, this review is selective rather than comprehensive. Its motivation was to highlight selected prospective inputs from nanocarbon science towards the development of novel dye sensitized solar cells with improved efficiency, durability, and cost. PMID:23729170

Kavan, Ladislav

2013-06-01

319

Near-Field Electromagnetic Theory for Thin Solar Cells  

NASA Astrophysics Data System (ADS)

Current methods for evaluating solar cell efficiencies cannot be applied to low-dimensional structures where phenomena from the realm of near-field optics prevail. We present a theoretical approach to analyze solar cell performance by allowing rigorous electromagnetic calculations of the emission rate using the fluctuation-dissipation theorem. Our approach shows the direct quantification of the voltage, current, and efficiency of low-dimensional solar cells. This approach is demonstrated by calculating the voltage and the efficiency of a GaAs slab solar cell for thicknesses from several microns down to a few nanometers. This example highlights the ability of the proposed approach to capture the role of optical near-field effects in solar cell performance.

Niv, A.; Gharghi, M.; Gladden, C.; Miller, O. D.; Zhang, X.

2012-09-01

320

Plastic solar cells: breaking the 10% commercialization barrier  

NASA Astrophysics Data System (ADS)

Tandem solar cells provide an effective way to harvest a broader spectrum of solar radiation by combining two or more solar cells with different absorption ranges. However, for polymer solar cells (PSCs), the performance of tandem devices lags behind single-layer cells mainly due to the lack of a high-performance low-bandgap polymer with appropriate spectral response range. Here, we demonstrate a novel low bandgap conjugated polymer (~1.44 eV) specifically suitable for tandem structure. In the single-layer device, power conversion efficiency (PCE) of 6.5% was achieved. When the polymer was applied to tandem solar cells, we demonstrated a NREL certified PCE of 8.62%[1] . Further optimization on materials and devices of this system has lead to record breaking efficiency of 10.6%. Furthermore, the tandem devices show excellent stability due both to the intrinsic stability of the polymer and the advanced device structure.

Dou, Letian; You, Jingbi; Chen, Chun-Chao; Li, Gang; Yang, Yang

2012-09-01

321

Improvement of Stabilized Efficiency of Amorphous Silicon Solar Cell by SiH2Cl2 Addition  

NASA Astrophysics Data System (ADS)

The characteristics of mercury-sensitized photo-chemical vapor deposition (CVD) grown a-Si:H films and solar cells in the case of dichrolosilane (SiH2Cl2) addition were investigated. The films with a small amount of SiH2Cl2 addition exhibited high photosensitivity, low hydrogen content and low defect density. However, the cells with an i-layer grown by SiH2Cl2 addition showed a low fill factor. It was also observed by secondary ion mass spectroscopy (SIMS) measurements that about 1019 atom/cm3 Cl was incorporated into a-Si:H films, even at the flow rate ratio of 0.01 (SiH2Cl2 to SiH4). Furthermore, it was found that the excess Cl in a-Si:H films was removed by H2 dilution. In the case of H2 dilution together with SiH2Cl2 addition to the i-layer of a-Si solar cells, a high fill factor and high quantum efficiencies, particularly in the medium wavelength region was observed. From numerical analysis, it was determined that the improvement was due to the increase of the electric field in the medium of the i-layer after light soaking. As a result, we achieved a high stabilized efficiency of 9.0% for a 1 cm2 single-junction a-Si:H solar cell.

Dairiki, Koji; Yamada, Akira; Konagai, Makoto

1999-07-01

322

Photon-degradation effects in terrestrial silicon solar cells  

Microsoft Academic Search

An unexplained instability in terrestrial solar-cell output under various use conditions has been observed. The effect is similar to but not identical with previously observed photon-induced degradation phenomenon in radiation-damaged space solar cells. Reduction in cell output is observed in n+\\/p cells upon exposure to illumination or upon the application of a sufficiently high forward bias. Conversely, an enhancement in

V. G. Weizer; H. W. Brandhorst; J. D. Broder; R. E. Hart; J. H. Lamneck

1979-01-01

323

Chemical reactions driven by concentrated solar energy  

Microsoft Academic Search

Solar energy can be used for driving endothermic reactions, either photochemically or thermally. The fraction of the solar spectrum that can be photochemically active is quite small. Therefore, it is desirable to be able to combine photochemical and thermal processes in order to increase the overall efficiency. Two thermally driven reactions are being studied: oil shale gasification and methane reforming.

Moshe Levy

1991-01-01

324

Effective diffusion length of multicrystalline solar cells  

NASA Astrophysics Data System (ADS)

Previous definitions of effective diffusion length 0268-1242/13/7/021/img1 of a multicrystalline semiconductor are reviewed. A new definition is proposed, which is based on the comparison of the current collected from the base of a multicrystalline solar cell and a single-crystal cell for uniform carrier generation, and holds for any sample thickness. An analytical expression for 0268-1242/13/7/021/img1 is obtained from the solution of the three-dimensional equation for the charge collection probability 0268-1242/13/7/021/img3 inside a grain with square cross section. This expression is used to numerically study the dependence of 0268-1242/13/7/021/img1 on the bulk diffusion length, grain size and grain boundary recombination velocity, and to make a comparison with previous specifications of 0268-1242/13/7/021/img1. The results indicate, in particular, that 0268-1242/13/7/021/img1 is the value that would be determined by the surface photovoltage method. The case of a cell with grains of different properties is briefly discussed and an average 0268-1242/13/7/021/img1 is defined. It is also shown that 0268-1242/13/7/021/img3 can be used to calculate the contribution of the base to the reverse saturation current of the cell.

Donolato, C.

1998-07-01

325

AlGaAs Top Solar Cell for Mechanical Attachment in a Multi-Junction Tandem Concentrator Solar Cell Stack.  

National Technical Information Service (NTIS)

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. Mecha...

L. C. Dinetta M. H. Hannon J. B. Mcneely A. M. Barnett

1991-01-01

326

Nanoparticle distribution in polymer solar cells  

NASA Astrophysics Data System (ADS)

Polymer based solar cells (PSC) hold the promise of cheap, versatile devices for harnessing solar energy. A widely studied PSC is poly-3-hexylthiophene (P3HT) blended with [6,6] - phenyl-C61 - butyric acid methyl ester (PCBM) nanoparticles. The acceptor PCBM is needed to inhibit exciton recombination, thus, proper PCBM distribution is critical for photovoltaic performance. However, determining this distribution is challenging, as PCBM is extremely difficult to distinguish from P3HT via standard techniques like microscopy or x-ray diffraction. Neutron scattering presents a solution, as the scattering potential for PCBM is ˜5 x that of P3HT. Thus, we have studied PCBM:P3HT thin film samples using neutron reflectometry, which is sensitive to the compositional depth profile.[1] Measurements were conducted both with a weak scatterer (air) and then with a strong scatterer (D2O) backing the sample, such that the depth profile could be calculated from the reflectometry data with no fitting parameters, and/or model fitted with virtually no ambiguity. We find that PCBM aggregates near the substrate and surface interfaces of the P3HT film, implying that the PCBM is not optimally distributed for best photovoltaic performance. In general, this work demonstrates the extreme utility of neutron reflectometry for studying this class of materials. [1] Kiel, et al. Soft Matter, DOI:10.1039/B920979D (2009).

Kirby, B. J.; Kiel, J. W.; Maranville, B. B.; Majkrzak, C. F.; Mackay, M. E.

2010-03-01

327

Photovoltaic technology: the case for thin-film solar cells  

PubMed

The advantages and limitations of photovoltaic solar modules for energy generation are reviewed with their operation principles and physical efficiency limits. Although the main materials currently used or investigated and the associated fabrication technologies are individually described, emphasis is on silicon-based solar cells. Wafer-based crystalline silicon solar modules dominate in terms of production, but amorphous silicon solar cells have the potential to undercut costs owing, for example, to the roll-to-roll production possibilities for modules. Recent developments suggest that thin-film crystalline silicon (especially microcrystalline silicon) is becoming a prime candidate for future photovoltaics. PMID:10426984

Shah; Torres; Tscharner; Wyrsch; Keppner

1999-07-30

328

New liquid crystal-embedded PVdF- co -HFP-based polymer electrolytes for dye-sensitized solar cell applications  

Microsoft Academic Search

Liquid crystal (LC; E7 and\\/or ML-0249)-embedded, poly(vinylidenefluoride-co-hexafluoropropylene) (PVdF-co-HFP)-based, polymer electrolytes were prepared for use in dye-sensitized solar cells (DSSCs). The electrolytes contained\\u000a 1-methyl-3-propylimidazolium iodide (PMII), tetrabutylammonium iodide (TBAI), and iodine (I\\u000a 2), which participate in theI\\u000a 3\\u000a ? \\/I\\u000a ? redox couple. The incorporation of photochemically stable PVdF-co-HFP in the DSSCs created a stable polymer electrolyte that resisted leakage and

G. Vijayakumar; Meyoung Jin Lee; Myungkwan Song; Sung-Ho Jin; Jae Wook Lee; Chan Woo Lee; Yeong-Soon Gal; Hyo Jin Shim; Yongku Kang; Gi-Won Lee; Kyungkon Kim; Nam-Gyu Park; Suhkmann Kim

2009-01-01

329

Solar cells incorporating light harvesting arrays  

DOEpatents

A solar cell incorporates a light harvesting array that comprises: (a) a first substrate comprising a first electrode; and (b) a layer of light harvesting rods electrically coupled to the first electrode, each of the light harvesting rods comprising a polymer of Formula I: X.sup.1.paren open-st.X.sup.m+1).sub.m (I) wherein m is at least 1, and may be from two, three or four to 20 or more; X.sup.1 is a charge separation group (and preferably a porphyrinic macrocycle, which may be one ligand of a double-decker sandwich compound) having an excited-state of energy equal to or lower than that of X.sup.2 ; and X.sup.2 through X.sup.m+1 are chromophores (and again are preferably porphyrinic macrocycles).

Lindsey, Jonathan S. (Raleigh, NC); Meyer, Gerald J. (Baltimore, MD)

2002-01-01

330

Core-shell silicon nanowire solar cells  

PubMed Central

Silicon nanowires can enhance broadband optical absorption and reduce radial carrier collection distances in solar cell devices. Arrays of disordered nanowires grown by vapor-liquid-solid method are attractive because they can be grown on low-cost substrates such as glass, and are large area compatible. Here, we experimentally demonstrate that an array of disordered silicon nanowires surrounded by a thin transparent conductive oxide has both low diffuse and specular reflection with total values as low as < 4% over a broad wavelength range of 400?nm < ? < 650?nm. These anti-reflective properties together with enhanced infrared absorption in the core-shell nanowire facilitates enhancement in external quantum efficiency using two different active shell materials: amorphous silicon and nanocrystalline silicon. As a result, the core-shell nanowire device exhibits a short-circuit current enhancement of 15% with an amorphous Si shell and 26% with a nanocrystalline Si shell compared to their corresponding planar devices.

Adachi, M. M.; Anantram, M. P.; Karim, K. S.

2013-01-01

331

Hot exciton dissociation in polymer solar cells  

NASA Astrophysics Data System (ADS)

The standard picture of photovoltaic conversion in all-organic bulk heterojunction solar cells predicts that the initial excitation dissociates at the donor/acceptor interface after thermalization. Accordingly, on above-gap excitation, the excess photon energy is quickly lost by internal dissipation. Here we directly target the interfacial physics of an efficient low-bandgap polymer/PC60BM system. Exciton splitting occurs within the first 50?fs, creating both interfacial charge transfer states (CTSs) and polaron species. On high-energy excitation, higher-lying singlet states convert into hot interfacial CTSs that effectively contribute to free-polaron generation. We rationalize these findings in terms of a higher degree of delocalization of the hot CTSs with respect to the relaxed ones, which enhances the probability of charge dissociation in the first 200?fs. Thus, the hot CTS dissociation produces an overall increase in the charge generation yield.

Grancini, G.; Maiuri, M.; Fazzi, D.; Petrozza, A.; Egelhaaf, H.-J.; Brida, D.; Cerullo, G.; Lanzani, G.

2013-01-01

332

Efficiency of silicon solar cells containing chromium  

DOEpatents

Efficiency of silicon solar cells containing about 10.sup.15 atoms/cm.sup.3 of chromium is improved about 26% by thermal annealing of the silicon wafer at a temperature of 200.degree. C. to form chromium precipitates having a diameter of less than 1 Angstrom. Further improvement in efficiency is achieved by scribing laser lines onto the back surface of the wafer at a spacing of at least 0.5 mm and at a depth of less than 13 micrometers to preferentially precipitate chromium near the back surface and away from the junction region of the device. This provides an economical way to improve the deleterious effects of chromium, one of the impurities present in metallurgical grade silicon material.

Frosch, Robert A. Administrator of the National Aeronautics and Space (New Port Beach, CA); Salama, Amal M. (New Port Beach, CA)

1982-01-01

333

Research in Photochemical Energy Conversion.  

National Technical Information Service (NTIS)

The results of investigations dealing with the following topics in photochemical energy conversion are presented: Apparatus for Photochemical Studies; Studies of Charge Transfer Systems; The Photochemistry of Perinaphthenone; The Photoreduction of Phenant...

K. Weiss

1971-01-01

334

Semitransparent organic solar cells with organic wavelength dependent reflectors  

NASA Astrophysics Data System (ADS)

Semitransparent organic solar cells employing solution-processable organic wavelength dependent reflectors of chiral nematic (cholesteric) liquid crystals are demonstrated. The cholesteric liquid crystal (CLC) reflects only in a narrow band of the solar spectrum and remains transparent for the remaining wavelengths. The reflective band is matched to the absorption spectrum of the organic solar cell such that only unabsorbed photons that can contribute to the photocurrent are reflected to pass through the active layer a second time. In this way, the efficiency of semitransparent organic solar cells can be enhanced without significant transparency losses. An efficiency increase of 6% was observed when a CLC reflector with a reflection band of 540-620 nm was used, whereas the transparency of the organic solar cells is only suppressed in the 80 nm narrow bandwidth.

Galagan, Yulia; Debije, Michael G.; Blom, Paul W. M.

2011-01-01

335

Results from the IMP-J violet solar cell experiment and violet cell balloon flights  

Microsoft Academic Search

The Interplanetary Monitoring Platform-J violet solar cell experiment was flown in an orbit with mild thermal cycling and low hard-particle radiation. The results of the experiment show that violet cells degrade at about the same rate as conventional cells in such an orbit. Balloon flight measurements show that violet solar cells produce approximately 20% more power than conventional cells.

E. M. Gaddy

1976-01-01

336

Area-scaling of organic solar cells  

NASA Astrophysics Data System (ADS)

We report on the performance of organic solar cells based on pentacene/C60 heterojunctions as a function of active area. Devices with areas of 0.13 and 7 cm2 were fabricated on indium-tin-oxide (ITO) coated glass. Degradation of the performance with increased area is observed and analyzed in terms of the power loss density concept. The various power loss contributions to the total series resistance (RSA) are measured independently and compared to the values of the series resistance extracted from the current-voltage characteristics using a Shockley equivalent circuit model. The limited sheet resistance of ITO is found to be one of the major limiting factors when the area of the cell is increased. To reduce the effects of series resistance, thick, electroplated, metal grid electrodes were integrated with ITO in large-area cells. The metal grids were fabricated directly onto ITO and passivated with an insulator to prevent electrical shorts during the deposition of the top Al electrode. By integrating metal grids onto ITO, the series resistance could be reduced significantly yielding improved performance. Design guidelines for metal grids are described and tradeoffs are discussed.

Choi, Seungkeun; Potscavage, William J.; Kippelen, Bernard

2009-09-01

337

Surface Plasmon Enhancement of Organic Solar Cells  

NASA Astrophysics Data System (ADS)

Organic photovoltaic (OPV) devices are inherently less efficient than silicon based devices. The short electron diffusion lengths in OPVs require the cells to be kept thin, diminishing their light absorption. One way to increase the absorption of these devices is to launch surface plasmons (SPs) along one of the electrodes at specific wavelengths in the solar spectrum. SPs are coherent electron oscillations that exist at the surface of a metal-dielectric boundary, and serve to focus light at the metal surface. This increase in absorption ultimately impacts the overall efficiency of the device. The OPV cells are fabricated on top of glass slides and consist of an organic heterojunction active layer residing between ITO and aluminum electrodes. SP coupling is achieved by forming sinusoidal gratings of various periods along the active layer/Al electrode boundary. Efficiency measurements of patterned and unpatterned samples were taken to determine if the gratings have any effect on the cell efficiency at the predicted wavelengths. No significant changes in efficiency have been observed, which could be due to the abnormally low efficiencies of the devices that were tested.

Shope, David; Steele, Jennifer

2011-10-01

338

Enhancing Solar Cell Efficiencies through 1-D Nanostructures  

Microsoft Academic Search

The current global energy problem can be attributed to insufficient fossil fuel supplies and excessive greenhouse gas emissions\\u000a resulting from increasing fossil fuel consumption. The huge demand for clean energy potentially can be met by solar-to-electricity\\u000a conversions. The large-scale use of solar energy is not occurring due to the high cost and inadequate efficiencies of existing\\u000a solar cells. Nanostructured materials

Kehan Yu; Junhong Chen

2009-01-01

339

Solar Cell Energy Availability From Around the Country  

NSDL National Science Digital Library

Solar cells have varying amounts of effectiveness depending on factors such as latitude and cloud coverage. For example, locations with more cloud coverage will produce less solar energy. By comparing the monthly averages of surface downward radiation in various locations around the United States, students can analyze areas that would be more or less beneficial to having solar panels per month. This lesson will introduce students to difference plots and how they can analyze such information.

340

High efficiency thin film cadmium telluride solar cells  

NASA Astrophysics Data System (ADS)

Cadmium sulfide (CdS), grown from an aqueous solution, and zinc oxide (ZnO), cadmium zinc sulfide (Cd1-xZnxS), and zinc selenide (ZnSe), deposited by metalorganic chemical vapor deposition (MOCVD), have been used as the window for thin film cadmium telluride (CdTe) solar cells. Thin film solar cells were prepared by the successive deposition of the window and p-CdTe (by MOCVD and close-spaced sublimation, CSS) on SnO2:F/glass substrates. CdS/CdTe(CSS) solar cells show considerably better characteristics than CdS/CdTe(MOCVD) solar cells because of the better microstructure of CSS CdTe films. Total area conversion efficiency of 14.6%, verified by the National Renewable Energy Laboratory, has been achieved for solar cells of about 1 cm2 area. Solar cell prepared by using ZnO, ZnSe, or Cd1-xZnxS as window have significantly lower photovoltage than CdS/CdTe solar cells.

Chu, T. L.; Chu, Shirley S.; Britt, J.; Chen, G.; Ferekides, C.; Schultz, N.; Wang, C.; Wu, C. Q.

1992-12-01

341

The photosensitizer disulfonated aluminum phthalocyanine reduces uptake and alters trafficking of fluid phase endocytosed drugs in vascular endothelial cells-Impact on efficacy of photochemical internalization.  

PubMed

Targeting cancer vasculature is an emerging field in cancer treatment. Photochemical internalization (PCI) is a drug delivery technology based on photochemical lysis of drug-bearing endocytic vesicles originally designed to target cancer cells. Recent investigations have revealed a lower PCI efficacy in vascular endothelial cells (HUVECs) in vitro than in HT1080 fibrosarcoma cells. This manuscript aims to explore the limiting factor for the PCI effect in HUVECs. Cellular uptake of the photosensitizers AlPcS2a and TPPS2a, and a model compound for macromolecular drugs taken up by fluid phase endocytosis, Alexa(488)-dextran, was explored by flow cytometry. The uptake of AlPcS2a and TPPS2a was 3.8-fold and 37-fold higher in HUVECs than in HT1080 cells, respectively, while the Alexa(488)-dextran uptake was 50% lower. AlPcS2a (but not TPPS2a) was shown to reduce Alexa(488)-dextran uptake in a concentration-dependent manner, resulting in 66% and 33% attenuation of Alexa(488)-dextran uptake at 20?g/ml AlPcS2a in HUVECs and HT1080 cells respectively. Studies of intracellular localization of Alexa(488)-dextran and AlPcS2a by confocal microscopy in HUVECs uncovered a concentration-dependent AlPcS2a-induced inhibition of Alexa(488)-dextran trafficking into AlPcS2a-stained and acidic vesicles. The localization of Alexa(488)-dextran to AlPcS2a-localizing compartments was reduced by 40% when the AlPcS2a concentration was increased from 5 to 20?g/ml. The treatment dose of AlPcS2a was found to influence on the efficacy of PCI of saporin, but to a lesser extent than expected considering the data from cellular uptake and intracellular trafficking of Alexa(488)-dextran. The implications of these results for further development of vascular targeting-PCI are discussed. PMID:23876343

Vikdal, Marie; Generalov, Roman; Berg, Kristian

2013-07-20

342

Thin multi-junction solar cells of III-V materials to advance solar energy harvesting  

NASA Astrophysics Data System (ADS)

Significant advancements in photovoltaic solar cells are required to support large-scale energy demands with solar power. The first generation of solar cells (SC) available today uses Si. While Si is highly abundant and these types of SC can be easily manufactured, the best power conversion efficiency is only 24%. Developing photovoltaic SC using III-V materials may increase the efficiency while decreasing the manufacturing costs associated with cell fabrication. This paper studies the opportunity to improve two-junctions solar cells made of III-V materials by making the layers very thin and including the antireflective layer in the first junction. In terms of light harvesting, the anti-reflective layer made of a semiconductor is shown to absorb the most part of the incident light.

Castelletto, S.; Parker, A.

2013-09-01

343

Neural Network Modeling of Degradation of Solar Cells  

SciTech Connect

Neural network modeling has been used to predict the degradation in conversion efficiency of solar cells in this work. The model takes intensity of light, temperature and exposure time as inputs and predicts the conversion efficiency of the solar cell. Backpropagation algorithm has been used to train the network. It is found that the neural network model satisfactorily predicts the degradation in efficiency of the solar cell with exposure time. The error in the computed results, after comparison with experimental results, lies in the range of 0.005-0.01, which is quite low.

Gupta, Himanshu; Ghosh, Bahniman [Department of Electrical Engineering, Indian Institute of Technology, Kanpur, 208016 (India); Banerjee, Sanjay K. [Department of Electrical and Computer Engineering, University of Texas at Austin, Austin, TX, 78758 (United States)

2011-05-25

344

Accelerated aging of GaAs concentrator solar cells  

SciTech Connect

An accelerated aging study of AlGaAs/GaAs solar cells has been completed. The purpose of the study was to identify the possible degradation mechanisms of AlGaAs/GaAs solar cells in terrestrial applications. Thermal storage tests and accelerated AlGaAs corrosion studies were performed to provide an experimental basis for a statistical analysis of the estimated lifetime. Results of this study suggest that a properly designed and fabricated AlGaAs/GaAs solar cell can be mechanically rugged and environmentally stable with projected lifetimes exceeding 100 years.

Gregory, P.E.

1982-04-01

345

PHOTOCHEMICAL AEROSOL DYNAMICS  

EPA Science Inventory

New data are reported on (1) the rate of formation of condensable chemical species by photochemical reactions, (2) the effect of the reaction products on the particle size distribution and (3) the distribution of reaction products as a function of particle size. Gas-to-particle c...

346

PHOTOCHEMICAL REACTIVITY OF PERCHLOROETHYLENE  

EPA Science Inventory

Perchloroethylene (PCE), a solvent used in dry cleaning, has been suspected of contributing significantly to photochemical ozone/oxidant (O3/Ox) problems in urban atmospheres. Past evidence, however, was neither complete nor consistent. To interpret more conclusively the past evi...

347

Photochemical tissue bonding  

DOEpatents

Photochemical tissue bonding methods include the application of a photosensitizer to a tissue and/or tissue graft, followed by irradiation with electromagnetic energy to produce a tissue seal. The methods are useful for tissue adhesion, such as in wound closure, tissue grafting, skin grafting, musculoskeletal tissue repair, ligament or tendon repair and corneal repair.

Redmond, Robert W. (Brookline, MA); Kochevar, Irene E. (Charlestown, MA)

2012-01-10

348

Crystalline silicon solar cells with micro/nano texture  

NASA Astrophysics Data System (ADS)

Crystalline silicon solar cells with two-scale texture consisting of random upright pyramids and surface nanotextured layer directly onto the pyramids are prepared and reflectance properties and I-V characteristics measured. Random pyramids texture is produced by etching in an alkaline solution. On top of the pyramids texture, a nanotexture is developed using an electroless oxidation/etching process. Solar cells with two-scale surface texturization are prepared following the standard screen-printing technology sequence. The micro/nano surface is found to lower considerably the light reflectance of silicon. The short wavelengths spectral response (blue response) improvement is observed in micro/nano textured solar cells compared to standard upright pyramids textured cells. An efficiency of 17.5% is measured for the best micro/nano textured c-Si solar cell. The efficiency improvement is found to be due to the gain in both Jsc and Voc.

Dimitrov, Dimitre Z.; Du, Chen-Hsun

2013-02-01

349

Solar Cell light trapping beyond the ray optic limit.  

PubMed

In 1982, Yablonovitch proposed a thermodynamic limit on light trapping within homogeneous semiconductor slabs, which implied a minimum thickness needed to fully absorb the solar spectrum. However, this limit is valid for geometrical optics but not for a new generation of subwavelength solar absorbers such as ultrathin or inhomogeneously structured cells, wire-based cells, photonic crystal-based cells, and plasmonic cells. Here we show that the key to exceeding the conventional ray optic or so-called ergodic light trapping limit is in designing an elevated local density of optical states (LDOS) for the absorber. Moreover, for any semiconductor we show that it is always possible to exceed the ray optic light trapping limit and use these principles to design a number of new solar absorbers with the key feature of having an elevated LDOS within the absorbing region of the device, opening new avenues for solar cell design and cost reduction. PMID:22149061

Callahan, Dennis M; Munday, Jeremy N; Atwater, Harry A

2012-01-03

350

Understanding junction breakdown in multicrystalline solar cells  

NASA Astrophysics Data System (ADS)

Extensive investigations on industrial multicrystalline silicon solar cells have shown that, for standard 1 ? cm material, acid-etched texturization, and in absence of strong ohmic shunts, there are three different types of breakdown appearing in different reverse bias ranges. Between -4 and -9 V there is early breakdown (type 1), which is due to Al contamination of the surface. Between -9 and -13 V defect-induced breakdown (type 2) dominates, which is due to metal-containing precipitates lying within recombination-active grain boundaries. Beyond -13 V we may find in addition avalanche breakdown (type 3) at etch pits, which is characterized by a steep slope of the I-V characteristic, avalanche carrier multiplication by impact ionization, and a negative temperature coefficient of the reverse current. If instead of acid-etching alkaline-etching is used, all these breakdown classes also appear, but their onset voltage is enlarged by several volts. Also for cells made from upgraded metallurgical grade material these classes can be distinguished. However, due to the higher net doping concentration of this material, their onset voltage is considerably reduced here.

Breitenstein, Otwin; Bauer, Jan; Bothe, Karsten; Kwapil, Wolfram; Lausch, Dominik; Rau, Uwe; Schmidt, Jan; Schneemann, Matthias; Schubert, Martin C.; Wagner, Jan-Martin; Warta, Wilhelm

2011-04-01

351

Solar Hydrogen Fuel Cell Projects at Brooklyn Tech  

ERIC Educational Resources Information Center

This article describes the projects on solar hydrogen powered vehicles using water as fuel conducted by teams at Brooklyn Technical High School. Their investigations into the pure and applied chemical thermodynamics of hydrogen fuel cells and bio-inspired devices have been consolidated in a new and emerging sub-discipline that they define as solar

Fedotov, Alex; Farah, Shadia; Farley, Daithi; Ghani, Naureen; Kuo, Emmy; Aponte, Cecielo; Abrescia, Leo; Kwan, Laiyee; Khan, Ussamah; Khizner, Felix; Yam, Anthony; Sakeeb, Khan; Grey, Daniel; Anika, Zarin; Issa, Fouad; Boussayoud, Chayama; Abdeldayem, Mahmoud; Zhang, Alvin; Chen, Kelin; Chan, Kameron Chuen; Roytman, Viktor; Yee, Michael

2010-01-01

352

Solar Cell and Array Standardization for Air Force Spacecraft.  

National Technical Information Service (NTIS)

Efforts have been in progress to evaluate and to accomplish solar cell and array standardization for Air Force spacecraft. Analysis results indicate that the array area and weight penalties that typically would be involved in the use of a standard solar c...

H. J. Killian E. Wade J. F. Wise H. T. Sampson

1974-01-01

353

Natural and simulated hypervelocity impacts into solar cells  

Microsoft Academic Search

The solar array which was returned to Earth from the Hubble Space Telescope (HST) in 1993, after 3.62 years of space exposure in low Earth orbit (LEO), has offered the opportunity to document populations of natural micrometeoroids and artificial “space debris”. Residues from the hypervelocity impact (HVI) of material deposited in 25 individual solar cells from the array have been

G. A. Graham; A. T. Kearsley; M. M. Grady; I. P. Wright; M. K. Herbert; J. A. M. McDonnell

1999-01-01

354

Nanostructured photovoltaic devices for next generation solar cell  

Microsoft Academic Search

As the search for alternative sources of energy other than petroleum continues to expand, solar energy conversion has already been identified as one of the most promising technologies. In the past few years there has been extensive research focused on the next generation solar cells that can exceed the Shockley-Queisser limit (a model that predicts the maximum achievable efficiency for

Sung Jin Kim

2008-01-01

355

Concentrator solar-cell flash tester. [Program SOLAR1 is listed that analyzes data from test  

Microsoft Academic Search

A method is described for testing solar cells at high concentrations in a laboratory environment without the need of coolant loops, precision tracking apparatus or dependence on cloud-free days. A complete Voltage-Current (V-I) characteristic curve for a solar cell is taken during one flash of a Xenon lamp light source. A comparison of this testing apparatus and an existing outside

Hibray

1982-01-01

356

28% efficient GaAs concentrator solar cells  

SciTech Connect

AlGaAs/GaAs heteroface solar concentrator cells which exhibit efficiencies in excess of 27% at high solar concentrations (>400 suns, AM1.5D, 100 mW/cm/sup 2/) have been fabricated with both n/p and p/n configurations. The best n/p cell achieved an efficiency of 28.1% around 400 suns, and the best p/n cell achieved an efficiency of 27.5% around 1000 suns. The high performance of these GaAs concentrator cells compared to our earlier high-efficiency cells was due to improved control of the MOCVD growth conditions and improved cell fabrication procedures (gridline definition and edge passivation). The design parameters of the solar cell structures and optimized grid pattern were determined with a realistic computer modeling program. An evaluation of the device characteristics and implications regarding future GaAs concentrator cell development is presented. 12 refs., 8 figs.

MacMillan, H.F.; Hamaker, H.C.; Kaminar, N.R.; Kuryla, M.S.; Ristow, M.L.; Liu, D.D.; Virshup, G.F.; Gee, J.M.

1988-01-01

357

The physics and modeling of gallium arsenide solar cells  

SciTech Connect

Gallium arsenide is a versatile semiconductor used in many devices. Due to its nearly ideal bandgap energy for solar energy conversion and its compatibility with AlGaAs, gallium arsenide's use in solar cells has been widespread and is growing. Only its chief rival, silicon, is more popular as a high-efficiency material. To continue gallium arsenide's growth, this research was conducted for the purpose of finding improved models for single-crystal GaAs solar cells. The research objectives were: (1) to characterize experimental GaAs cells, (2) to develop predictive device models for AlGaAs/GaAs, and (3) to project the potential of GaAs-based cells. Considering the number of laboratories fabricating GaAs solar cells, there has been a surprisingly limited number of experimental studies that have sought the understanding of GaAs device physics. To extend our knowledge in this area, a study of laboratory-grown cells was conducted. The goal was to uncover the mechanism that limit the performance of today's best GaAs solar cells. The information derived from this study has been used to develop improved models that successfully predict GaAs solar-cell performance. A two-dimensional numerical simulation program, capable of modeling GaAs/AlGaAs heterostructures, was developed. The simulation program is the culmination of earlier research efforts to GaAs/AlGaAs device modeling. It is not possible, using the numerical simulation program, to accurately assess the potential of GaAs solar cells. The numerical model projects conversion efficiencies of over 30% under concentrated sunlight, supporting earlier forecasts that GaAs could play an integral part of future solar-cell technology.

DeMoulin, P.D.

1988-01-01

358

Microcrystalline silicon solar cells deposited at high rates  

NASA Astrophysics Data System (ADS)

Hydrogenated microcrystalline silicon (?c-Si:H) thin-film solar cells were prepared at high rates by very high frequency plasma-enhanced chemical vapor deposition under high working pressure. The influence of deposition parameters on the deposition rate (RD) and the solar cell performance were comprehensively studied in this paper, as well as the structural, optical, and electrical properties of the resulting solar cells. Reactor-geometry adjustment was done to achieve a stable and homogeneous discharge under high pressure. Optimum solar cells are always found close to the transition from microcrystalline to amorphous growth, with a crystallinity of about 60%. At constant silane concentration, an increase in the discharge power did hardly increase the deposition rate, but did increase the crystallinity of the solar cells. This results in a shift of the ?c-Si:H/a-Si:H transition to higher silane concentration, and therefore leads to a higher RD for the optimum cells. On the other hand, an increase in the total flow rate at constant silane concentration did lead to a higher RD, but lower crystallinity. With this shift of the ?c-Si:H/a-Si:H transition at higher flow rates, the RD for the optimum cells decreased. A remarkable structure development along the growth axis was found in the solar cells deposited at high rates by a ``depth profile'' method, but this does not cause a deterioration of the solar cell performance apart from a poorer blue-light response. As a result, a ?c-Si:H single-junction p-i-n solar cell with a high efficiency of 9.8% was deposited at a RD of 1.1 nm/s.

Mai, Y.; Klein, S.; Carius, R.; Wolff, J.; Lambertz, A.; Finger, F.; Geng, X.

2005-06-01

359

Approaches to Future Generation Photovoltaics and Solar Fuels: Quantum Dots, Arrays, and Quantum Dot Solar Cells  

SciTech Connect

One potential, long-term approach to more efficient and lower cost future generation solar cells for solar electricity and solar fuels is to utilize the unique properties of quantum dots (QDs) to control the relaxation pathways of excited states to enhance multiple exciton generation (MEG). We have studied MEG in close-packed PbSe QD arrays where the QDs are electronically coupled in the films and thus exhibit good transport while still maintaining quantization and MEG. We have developed simple, all-inorganic solution-processable QD solar cells that produce large short-circuit photocurrents and power conversion efficiencies above 5% via nanocrystalline p-n junctions. These solar cells show QYs for photocurrent that exceed 100% in the photon energy regions where MEG is possible; the photocurrent MEG QYs as a function of photon energy match those determined via time-resolved spectroscopy Recent analyses of the major effect of MEG combined with solar concentration on the conversion efficiency of solar cells will also be discussed.

Semonin, O.; Luther, J.; Beard, M.; Johnson, J.; Gao, J.; Nozik, A.

2012-01-01

360

[Photochemical degradation of chlorpyrifos in water].  

PubMed

In this paper, the effects of different light sources, temperature, pH, and water quality on the photochemical degradation of clilorpyrifos in water were examined under natural and simulated solar irradiation. The results showed that the photochemical degradation of chlorpyrifos in water followed the first order reaction, and its half-life was 0.62, 6.92, 19.74 and 22.50 h under high pressure mercury lamp (HPML), xenon lamp (XL), ultraviolet lamp (UV), and sunlight (SL) irradiation, respectively. Temperature had a significant effect on the degradation rate of chlorpyrifos, which was increased with increasing temperature and reached the maximum at 35 degrees C. The degradation rate of chlorpyrifos was stable both in acid and in neutral buffer solution, but enhanced in alkaline buffer solution. Water quality also had a significant effect, with a decreasing degradation rate of chlorpyrifos in the sequence of distilled water > tap water > river water > lake wate > paddy water. PMID:17044511

Wu, Xiangwei; Hua, Rimao; Tang, Feng; Li, Xuede; Cao, Haiqun; Yue, Yongde

2006-07-01

361

Consciousness can reduce the voltage of the output signal of solar cell  

Microsoft Academic Search

When the sun's light radiate on the solar cell, it can produce the output signal as the pho- tocurrent. We use the Data Acquisition Modules to record the voltage of the output signals. The v1 is voltage of the photocurrent of solar cell1; The v2 is the one of solar cell2. And these two solar cells stay side by side.

Dayong Cao

2011-01-01

362

Simulation of solar cells utilization on the surface of Mars  

NASA Astrophysics Data System (ADS)

Results concerning the simulation of solar cells operation on Mars surface are reported in this article. PV arrays based on silicon and gallium arsenide solar cells are analyzed under the assumption of both ideal and present state-of-the-art technology. Measurements performed by the Viking Landers are used as inputs. They refer to ambient temperature, wind speed and the optical depth of the Martian atmosphere. The incoming global solar radiation flux (direct, diffuse and ground reflected) is computed by using a model previously proposed by the author. A thermodynamic model of solar cell is developed. Simulations were performed for both Viking Landers 1 and 2 sites during all the four Martian seasons. Information about the optimum voltage and cell temperature is provided as well as details about the electric power supply and cell efficiency. Different sorts of stationary and tracking solar cells arrays are studied. The PV efficiency is obviously higher than that obtained under terrestrial conditions due to the lower ambient temperature on Mars. One confirms that the low operating temperatures will reduce the advantage in efficiency of GaAs solar cells over silicon. The strategy to be chosen for maximum power supply mainly depends on the atmospheric optical depth.

Badescu, Viorel

363

Advanced cost-effective crystalline silicon solar cell technologies  

Microsoft Academic Search

An overview is given concerning current industrial technologies, near future improvements and medium-term developments in the field of industrially viable crystalline silicon terrestrial solar cell fabrication (without concentration).

J. F Nijs; J Szlufcik; J Poortmans; S Sivoththaman; R. P Mertens

2001-01-01

364

Amorphous silicon/polycrystalline thin film solar cells.  

National Technical Information Service (NTIS)

An improved photovoltaic solar cell is described including a p-type amorphous silicon layer, intrinsic amorphous silicon, and an n-type polycrystalline semiconductor such as cadmium sulfide, cadmium zinc sulfide, zinc selenide, gallium phosphide, and gall...

H. S. Ullal

1991-01-01

365

Process Technology and Advanced Concepts: Organic Solar Cells (Fact Sheet)  

SciTech Connect

Capabilities fact sheet for the National Center for Photovoltaics: Process Technology and Advanced Concepts: Organic Solar Cell that includes scope, core competencies and capabilities, and contact/web information.

Not Available

2011-06-01

366

Thin-film silicon and GaAs solar cells  

SciTech Connect

The growth of thin films of crystalline silicon and GaAs on inexpensive substrates offers the promise of combining the high performance of single crystal solar cells with the low cost of thin-film solar cells. The large number of potential crystal growth processes for achieving the desired structure can be organized into melt growth, vapor phase growth, solid state growth and solution growth. Solution growth offers several advantages for the development of solar cell quality material on dissimilar substrates. Thin solar cell design, the selection criteria that led to the choice of solution growth, a description of the growth stages and the growth of silicon on glass and steel and GaAs on aluminum are described.

Barnett, A.M.; Hall, I.W.; Hall, R.B.; Mauk, M.G.; McNeely, J.B.; Tiller, W.A.; Zolper, J.C.

1984-05-01

367

Plasmonic nano-antenna a-Si:H solar cell.  

PubMed

In this work the effects of plasmonics, nano-focusing, and orthogonalization of carrier and photon pathways are simultaneously explored by measuring the photocurrents in an elongated nano-scale solar cell with a silver nanoneedle inside. The silver nanoneedles formed the support of a conformally grown hydrogenated amorphous silicon (a-Si:H) n-i-p junction around it. A spherical morphology of the solar cell functions as a nano-lens, focusing incoming light directly on the silver nanoneedle. We found that plasmonics, geometric optics, and Fresnel reflections affect the nanostructured solar cell performance, depending strongly on light incidence angle and polarization. This provides valuable insight in solar cell processes in which novel concepts such as plasmonics, elongated nanostructures, and nano-lenses are used. PMID:23262683

Di Vece, Marcel; Kuang, Yinghuan; van Duren, Stephan N F; Charry, Jamie M; van Dijk, Lourens; Schropp, Ruud E I

2012-12-01

368

Method of applying an antireflective coating to a solar cell  

SciTech Connect

A tantalum oxide antireflective coating is applied to a surface of a solar energy cell by depositing a layer of a suboxide of tantalum on the surface and then oxidizing the layer to an oxide approaching ta2o5.

Lindmayer, J.

1980-05-06

369

Thermoelastic Analysis of Solar Cell Arrays and Their Material Properties.  

National Technical Information Service (NTIS)

A thermoelastic stress analysis procedure is reported for predicting the thermally induced stresses and failures in silicon solar cell arrays. A prerequisite for the analysis is the characterization of the temperature-dependent thermal and mechanical prop...

M. A. Salama R. K. Yasui W. M. Rowe

1973-01-01

370

Epitaxial Solar Cells on Silicon EFG 'Ribbon' Substrates.  

National Technical Information Service (NTIS)

Epitaxial solar cell structures grown on polycrystalline silicon 'ribbon' substrates (prepared by the edge-defined-growth process) are compared to devices made by direct diffusion into similar material. Efficiency values of 10% (AM-1) have been achieved b...

H. Kressel R. V. D'Aiello P. H. Robinson

1975-01-01

371

Hybrid polymer solar cell based on cadmium selenide quantum dots  

NASA Astrophysics Data System (ADS)

High quality CdSe quantum dots (QDs) were synthesized using the hot injection method. These QDs were further used for the fabrication of Hybrid polymer solar cell (HPSC) using the low band gap polymer such as P3HT. The CdSe QD sensitized polymer solar cell was fabricated using the spin coating technique. The obtained HPSC is further characterized for their optical and solar cell studies. The optical absorbance and photoluminescence of the HPSC is in the visible regime. The solar cell O/P characteristics under 1 Sun illumination produced a promising 0.6% efficiency. The corresponding current density and open circuit photovoltage values were 0.88 mA/cm2 and 278 mV respectively.

More, Anup J.; Pawar, Sachin A.; Burungale, Vishal V.; Patil, Raghunath S.; Patil, Pramod S.

2013-06-01

372

Improved bulk heterojunction organic solar cells employing C70 fullerenes  

NASA Astrophysics Data System (ADS)

We show that the fullerene C70 is suitable to replace fullerene C60, which is commonly used as electron transporter and acceptor in small-molecule organic solar cells. It is shown that the higher absorption of C70 leads to high external quantum efficiencies of over 50% in the spectral range of 500-700 nm. By optimizing the energy level alignment to hole transport layers, the absorption, and the ratio of C70:zinc phthalocyanine (ZnPc) in a bulk heterojunction solar cell, an efficiency of ?=2.87% is achieved. This is a substantial improvement over an identical solar cell employing C60 having ?=2.27%. The efficiency increase is due to a higher photocurrent, while fill factor and open-circuit voltage for C70 and C60-containing organic solar cells remain comparable.

Pfuetzner, Steffen; Meiss, Jan; Petrich, Annette; Riede, Moritz; Leo, Karl

2009-06-01

373

High-efficiency heterojunction solar cells on crystalline germanium substrates  

NASA Astrophysics Data System (ADS)

We report stand-alone heterojunction (HJ) solar cells with conversion efficiencies of 5.9% and 7.2% on n-type and p-type crystalline germanium (c-Ge) substrates, respectively. The emitter of the HJ solar cells is formed by growing thin layers of highly doped hydrogenated microcrystalline silicon using plasma-enhanced chemical vapor deposition at temperatures close to 200 °C. The conversion efficiencies of the HJ solar cells are well-comparable with conventional devices fabricated at temperatures as high as 600 °C. We also study the surface passivation of c-Ge with hydrogenated amorphous and microcrystalline Si and correlate the passivation quality with the electrical performance of the HJ solar cells.

Hekmatshoar, Bahman; Shahrjerdi, Davood; Hopstaken, Marinus; Fogel, Keith; Sadana, Devendra K.

2012-07-01

374

Investigation of the texture surface silicon solar cell  

SciTech Connect

The optical and electrical properties of the texture surface silicon solar cell are analyzed and discussed. A new method of etching a texture surface by LiOH is presented and the mechanism of etching a texture surface is investigated.

Rongqiang, C.; Huilan, Q.

1983-10-01

375

European Roadmap of Multijunction Solar Cells and Qualification Status  

Microsoft Academic Search

A program for the development and qualification of advanced triple-junction space solar cells in Europe was initiated and supported by the European Space Agency ESA (contracts No. 18767\\/04\\/NL\\/FM \\

G. F. X. Strobl; T. Bergunde; W. Kostler; R. Kern; M. Meusel; G. Laroche; W. Zimmermann; A. W. Bett; F. Dimroth; W. Geens; S. Taylor; E. Fernandez; L. Gerlach; C. Signorini; G. Hey

2006-01-01

376

Plasmonic reflection grating back contacts for microcrystalline silicon solar cells  

NASA Astrophysics Data System (ADS)

We report on the fabrication and optical simulation of a plasmonic light-trapping concept for microcrystalline silicon solar cells, consisting of silver nanostructures arranged in square lattice at the ZnO:Al/Ag back contact of the solar cell. Those solar cells deposited on this plasmonic reflection grating back contact showed an enhanced spectral response in the wavelengths range from 500 nm to 1000 nm, when comparing to flat solar cells. For a particular period, even an enhancement of the short circuit current density in comparison to the conventional random texture light-trapping concept is obtained. Full three-dimensional electromagnetic simulations are used to explain the working principle of the plasmonic light-trapping concept.

Paetzold, U. W.; Moulin, E.; Michaelis, D.; Böttler, W.; Wächter, C.; Hagemann, V.; Meier, M.; Carius, R.; Rau, U.

2011-10-01

377

High Temperature Bonding Techniques for Solar Cell Array.  

National Technical Information Service (NTIS)

An adhesive for solar cell attachment to spacecraft substrates has been sought with an unusually demanding combination of properties. These include (1) a basic resistance to decomposition at 600 C in vacuum, (2) retention of elastic properties at liquid n...

G. LaFontaine F. Marsh H. Levin F. Sinsheimer G. Wolff

1977-01-01

378

Hydrogen Radical-Enhanced Growth of Solar Cells.  

National Technical Information Service (NTIS)

High-efficiency solar cells require multiple layers of compound semiconducting materials with different composition and/or doping. They are grown epitaxially in succession on a substrate. Mechanical requirements often specify abrupt changes in both compos...

J. M. Borrego S. K. Ghandhi

1991-01-01

379

Crystalline Si thin-film solar cells: a review  

Microsoft Academic Search

.   The present review summarizes the results of research efforts in the field of crystalline silicon thin-film solar cells on\\u000a foreign substrates. The large number of competing approaches can be broadly classified according to the grain size of the\\u000a crystalline Si films and the doping of the crystalline absorber. Currently, solar cells based on microcrystalline Si films\\u000a on glass with

R. B. Bergmann

1999-01-01

380

Third generation photovoltaics: solar cells for 2020 and beyond  

Microsoft Academic Search

Many working in the field of photovoltaics believe that ‘first generation’ silicon wafer-based solar cells sooner or later will be replaced by a ‘second generation’ of lower cost thin-film technology, probably also involving a different semiconductor. Historically, CdS, a-Si, CuInSe2, CdTe and, more recently, thin-film Si have been regarded as key thin-film candidates. Since any mature solar cell technology is

Martin A Green

2002-01-01

381

Amorphous silicon\\/polycrystalline thin film solar cells  

Microsoft Academic Search

An improved photovoltaic solar cell is described including a p-type amorphous silicon layer, intrinsic amorphous silicon, and an n-type polycrystalline semiconductor such as cadmium sulfide, cadmium zinc sulfide, zinc selenide, gallium phosphide, and gallium nitride. The polycrystalline semiconductor has an energy bandgap greater than that of the amorphous silicon. The solar cell can be provided as a single-junction device or

Ullal

1991-01-01

382

Low temperature quantum efficiency measurements on irradiated multijunction solar cells  

Microsoft Academic Search

This paper presents quantum efficiency (QE) measurements and analyses on monolithic triple junction (3J) InGaP\\/GaAs\\/Ge solar cells under both room (300K) and low temperature (130K) conditions. In measuring the quantum efficiency of multijunction solar cells, one must be careful to use the proper bias conditions to isolate the subcell of interest. This may be achieved by using external light sources

S. R. Messenger; J. H. Warner; P. P. Jenkins; R. J. Walters; J. R. Lorentzen

2008-01-01

383

Simple Photovoltaic Cells for Exploring Solar Energy Concepts  

ERIC Educational Resources Information Center

|Low-efficiency solar cells for educational purposes can be simply made in school or home environments using wet-chemistry techniques and readily available chemicals of generally low toxicity. Instructions are given for making solar cells based on the heterojunctions Cu/Cu[subscript 2]O, Cu[subscript 2]O/ZnO and Cu[subscript 2]S/ZnO, together with…

Appleyard, S. J.

2006-01-01

384

Silicon nanocrystals - a luminescence convertor applied to silicon solar cells  

Microsoft Academic Search

In this contribution we investigate an implementation of silicon nanocrystals (Si-nc) into photovoltaic in order to improve the performance of the solar cells. The Si-nc are prepared ex-situ from porous silicon and embedded into SiO\\/sub 2\\/ based spin-on-glasses (SOG) layers and deposited on standard silicon solar cell. We are presenting the photo luminescence properties of such a SOG\\/Si-nc layers. When

V. Svrcek; A. Slaoui; J.-C. Muller

2003-01-01

385

Recent technological advances in thin film solar cells  

SciTech Connect

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

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

1990-03-01

386

High-efficiency panchromatic hybrid Schottky solar cells.  

PubMed

Nanostructured Schottky inorganic-organic solar cells provide overall power conversion efficiencies exceeding 3%, with extremely large short-circuit photocurrents. The device EQE faithfully tracks the absorptance of the CdSe nanorods, and the IQE is approximately constant over the entire visible spectrum as opposed to a p-n junction hybrid solar cell fabricated with a highly absorbing organic polymer. PMID:23090941

Lee, Joun; Mubeen, Syed; Hernandez-Sosa, Gerardo; Sun, Yanming; Toma, Francesca M; Stucky, Galen D; Moskovits, Martin

2012-10-23

387

Thin film solar cell inflatable ultraviolet rigidizable deployment hinge  

US Patent & Trademark Office Database

A flexible inflatable hinge includes curable resin for rigidly positioning panels of solar cells about the hinge in which wrap around contacts and flex circuits are disposed for routing power from the solar cells to the power bus further used for grounding the hinge. An indium tin oxide and magnesium fluoride coating is used to prevent static discharge while being transparent to ultraviolet light that cures the embedded resin after deployment for rigidizing the inflatable hinge.

Simburger; Edward J. (Agoura, CA); Matsumoto; James H. (Los Angeles, CA); Giants; Thomas W. (Santa Monica, CA); Garcia, III; Alec (Santa Clarita, CA); Perry; Alan R. (Conifer, CA); Rawal; Suraj (Littleton, CO); Marshall; Craig H. (Littleton, CO); Lin; John K. H. (Middletown, DE); Day; Jonathan Robert (Dover, DE); Kerslake; Thomas W. (Strongsville, OH); Scarborough; Stephen E. (Seaford, DE)

2010-05-04

388

Nanocrystalline metal electrodes for high-efficiency organic solar cells  

Microsoft Academic Search

We demonstrate that indium (In) nanocrystals can be used as efficient small-work function electrodes for organic solar cells. A Schottky-barrier solar cell consisting of the In nanoelectrodes, a zinc phthalocyanine (ZnPc) film as a p-type organic semiconductor, and a gold counterelectrode were assembled by vacuum evaporation on an indium-tin-oxide substrate. Nanoscopic Schottky barriers, which are the origins of photovoltaic effects,

Tetsuya Taima; Masayuki Chikamatsu; Yuji Yoshida; Kazuhiro Saito; Kiyoshi Yase

2004-01-01

389

Silicon nanocrystals as a photoluminescence down shifter for solar cells  

Microsoft Academic Search

The effects of a Si-rich silicon oxide (SRO) layer containing silicon nanocrystals as photoluminescence down-shifter layer on a conventional Si solar cell were investigated. Two SRO layers with different thicknesses but same composition were deposited on top of Si solar cells by plasma-enhanced chemical vapor deposition and followed by high temperature annealing to precipitate silicon nanocrystals. The SRO layers absorb

Zhizhong Yuan; Georg Pucker; Alessandro Marconi; Fabrizio Sgrignuoli; Aleksei Anopchenko; Yoann Jestin; Lorenza Ferrario; Pierluigi Bellutti; Lorenzo Pavesi

2011-01-01

390

Polycrystalline silicon on glass for thin-film solar cells  

Microsoft Academic Search

Although most solar cell modules to date have been based on crystalline or polycrystalline wafers, these may be too material\\u000a intensive and hence always too expensive to reach the very low costs required for large-scale impact of photovoltaics on the\\u000a energy scene. Polycrystalline silicon on glass (CSG) solar cell technology was developed to address this difficulty as well\\u000a as perceived

Martin A. Green

2009-01-01

391

Polymer solar cells with enhanced fill factors  

NASA Astrophysics Data System (ADS)

Recent advances in polymer solar cell (PSC) performance have resulted from compressing the bandgap to enhance the short-circuit current while lowering the highest occupied molecular orbital to increase the open-circuit voltage. Nevertheless, PSC power conversion efficiencies are still constrained by low fill factors, typically below 70%. Here, we report PSCs with exceptionally high fill factors by combining complementary materials design, synthesis, processing and device engineering strategies. The donor polymers, PTPD3T and PBTI3T, when incorporated into inverted bulk-heterojunction PSCs with a PC71BM acceptor, result in PSCs with fill factors of 76-80%. The enhanced performance is attributed to highly ordered, closely packed and properly oriented active-layer microstructures with optimal horizontal phase separation and vertical phase gradation. The result is efficient charge extraction and suppressed bulk and interfacial bimolecular recombination. The high fill factors yield power conversion efficiencies of up to 8.7% from polymers with suboptimal bandgaps, suggesting that efficiencies above 10% should be realizable by bandgap modification.

Guo, Xugang; Zhou, Nanjia; Lou, Sylvia J.; Smith, Jeremy; Tice, Daniel B.; Hennek, Jonathan W.; Ortiz, Rocío Ponce; Navarrete, Juan T. López; Li, Shuyou; Strzalka, Joseph; Chen, Lin X.; Chang, Robert P. H.; Facchetti, Antonio; Marks, Tobin J.

2013-10-01

392

High efficacy thinned four-junction solar cell  

NASA Astrophysics Data System (ADS)

A thinned four-junction (4J) 1.88 eV GaInP/1.41 eV GaInAs/0.92 eV GaInNAs(Sb)/0.66 eV Ge solar cell is analyzed here versus the benchmark optically thick GaInP/GaInAs/Ge three-junction (3J) solar cell. Despite purposefully reducing the one sun AM1.5D current density to 12.4 mA cm-2 in the III-V subcells and 13.6 mA cm-2 in the bottom Ge subcell (1.2 mA cm-2 excess current density) and using less than 1.0 eV bandgap for the third subcell, ~3% higher theoretical power conversion efficiency is possible along with ~27% less parasitic resistive (I2R) power loss and ~45% less epitaxially grown compound semiconductor material in comparison to the benchmark three-junction solar cell. If we consider the efficacy of the solar cells in terms of power (W) per epitaxial layer thickness (µm), then the thinned 4J solar cell has ~93% greater efficacy (W/µmepilayer) than the benchmark 3J solar cell. Additionally, compositionally graded versus fixed composition passivating window and back surface field layers for improved charge carrier transport are examined.

Kirk, A. P.

2011-12-01

393

OTEC to hydrogen fuel cells - A solar energy breakthrough  

Microsoft Academic Search

Recent advances in fuel cell technology and development are discussed, which will enhance the Ocean Thermal Energy Conversion (OTEC)-hydrogen-fuel cell mode of energy utilization. Hydrogen obtained from the ocean solar thermal resources can either be liquified or converted to ammonia, thus providing a convenient mode of transport, similar to that of liquid petroleum. The hydrogen fuel cell can convert hydrogen

J. R. Roney

1981-01-01

394

Solar Cell is Housed in Light-Bulb Enclosure: An inexpensive solar-cell module uses a standard outdoor light-bulb enclosure.  

National Technical Information Service (NTIS)

This citation summarizes a one-page announcement of technology available for utilization. With the advent of a recently announced innovation in solar cell fabrication, the planar multijunction (PMJ) high voltage solar cell have been found. Housed in a con...

1981-01-01

395

Photochemical isotope separation  

DOEpatents

A process for separating isotopes by selective excitation of isotopic species of a volatile compound by tuned laser light. A highly cooled gas of the volatile compound is produced in which the isotopic shift is sharpened and defined. Before substantial condensation occurs, the cooled gas is irradiated with laser light precisely tuned to a desired wavelength to selectively excite a particular isotopic species in the cooled gas. The laser light may impart sufficient energy to the excited species to cause it to undergo photochemical reaction or even to photoionize. Alternatively, a two-photon irradiation may be applied to the cooled gas to induce photochemical reaction or photoionization. The process is particularly applicable to the separation of isotopes of uranium and plutonium.

Robinson, C. Paul (Los Alamos, NM); Jensen, Reed J. (Los Alamos, NM); Cotter, Theodore P. (Los Alamos, NM); Greiner, Norman R. (Los Alamos, NM); Boyer, Keith (Los Alamos, NM)

1987-01-01

396

Photochemical isotope separation  

DOEpatents

A process is described for separating isotopes by selective excitation of isotopic species of a volatile compound by tuned laser light. A highly cooled gas of the volatile compound is produced in which the isotopic shift is sharpened and defined. Before substantial condensation occurs, the cooled gas is irradiated with laser light precisely tuned to a desired wavelength to selectively excite a particular isotopic species in the cooled gas. The laser light may impart sufficient energy to the excited species to cause it to undergo photochemical reaction or even to photoionize. Alternatively, a two-photon irradiation may be applied to the cooled gas to induce photochemical reaction or photoionization. The process is particularly applicable to the separation of isotopes of uranium and plutonium. 8 figs.

Robinson, C.P.; Jensen, R.J.; Cotter, T.P.; Greiner, N.R.; Boyer, K.

1987-04-28

397

Photochemical ozone creation potentials  

Microsoft Academic Search

Goal, Scope and Background  Photochemical ozone creation potentials (POCPs) typically used in life cycle impact assessment (LCIA) to address the impact\\u000a category ‘photo-oxidant formation’ only provide factors for particular volatile organic compounds and do not take into account\\u000a background concentrations and meteorological conditions. However, the formation of ozone from volatile organic compounds (VOCs),\\u000a carbon monoxide (CO) and nitrogen oxides (NOx) is

Eric Labouze; Cécile Honoré; Lamya Moulay; Bénédicte Couffignal; Matthias Beekmann

2004-01-01

398

Visibly transparent polymer solar cells produced by solution processing.  

PubMed

Visibly transparent photovoltaic devices can open photovoltaic applications in many areas, such as building-integrated photovoltaics or integrated photovoltaic chargers for portable electronics. We demonstrate high-performance, visibly transparent polymer solar cells fabricated via solution processing. The photoactive layer of these visibly transparent polymer solar cells harvests solar energy from the near-infrared region while being less sensitive to visible photons. The top transparent electrode employs a highly transparent silver nanowire-metal oxide composite conducting film, which is coated through mild solution processes. With this combination, we have achieved 4% power-conversion efficiency for solution-processed and visibly transparent polymer solar cells. The optimized devices have a maximum transparency of 66% at 550 nm. PMID:22789123

Chen, Chun-Chao; Dou, Letian; Zhu, Rui; Chung, Choong-Heui; Song, Tze-Bin; Zheng, Yue Bing; Hawks, Steve; Li, Gang; Weiss, Paul S; Yang, Yang

2012-07-12

399

New directions in InP solar cell research  

SciTech Connect

Recent research efforts representing new directions in InP solar cell research are reviewed. These include heteroepitaxial growth on silicon and gallium arsenide substrates, V-grooved cells, large area high efficiency cells, and surface passivation. Improvements in heteroepitaxial cell efficiency are described together with processing of 19.1 percent, 4 sq cm cells. Recommendations are made for improvements in processing leading to increased efficiencies.

Weinberg, I.; Swartz, C.K.; Brinker, D.J.

1990-01-01

400

Using solar cells as microparticle detectors in low earth orbit  

NASA Astrophysics Data System (ADS)

On retrieval from low Earth orbit (LEO), the solar arrays from the European retrievable carrier (EuReCa) and one solar array wing of the Hubble Space Telescope (HST) were inspected for micrometeoroid and space debris impact damage. Seven-hundred-three and eight-hundred-fourteen impact sites respectively were analyzed in detail. Interpretation of particle parameters from this large data set can yield a useful measurement of the micrometeoroid and debris flux in LEO. Due to similar orbital parameters, this then provides a flux measurement complimentary to those measured by the timeband capture cell experiment (TiCCE) of the EuReCa spacecraft and detectors and exposed surfaces on the Long Duration Exposure Facility (LDEF). To allow comparison of data from the space retrieved solar cells to previous data, solar cell material, glass and aluminum targets were impacted for inter-calibration using the University of Kent's Light Gas Gun (LGG). An average of 20 impact sites on each target material per shot were measured. It was decided to consider only non-perforations of the 150 micron thick CMX cover glass, common to both EuReCa and HST solar cells. Trends in crater morphology of the laboratory impacts are discussed and compared to those from space impacts. The effects of impact angle and crater scaling with particle size are investigated and a conversion from appropriate solar cell crater parameters to the ballistic limit in aluminum is presented.

Shrine, Nicholas R.; Taylor, Emma A.; Yano, H.; Griffiths, Andrew D.; McDonnell, J. Anthony M.

1996-10-01

401

Laser-assisted solar cell metallization processing. Quarterly report, September 13-December 12, 1983  

SciTech Connect

The Westinghouse Electric Corporation has undertaken to investigate, develop, and characterize laser-assisted processing techniques utilized to produce the fine line, thin metal grid structures that are required to fabricate high-efficiency solar cells. Two basic techniques for metal deposition will be investigated, as follows: (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. The purpose of this contract is to investigate the various existing laser-assisted film deposition techniques in order to develop a new, cost-effective technology for solar cell metallization. The tasks that will be performed in the conduct of these investigations are detailed. In the first three months of this contract, a comprehensive literature search has been carried out on the various state-of-the-art laser-assisted techniques for metal deposition, including laser chemical vapor deposition and laser photolysis of organometallics, as well as laser-enhanced electroplating. A compact system for the experiments involving laser-assisted photolysis of gas-phase compounds has been designed and constructed. Initial experiments on laser-enhanced electro-plating have yielded very promising results, with linewidths as fine as 25 ..mu..m and plating speeds as high as 12 ..mu..m/sec being achieved.

Dutta, S.

1984-01-16

402

Influence of solar heating on the performance of integrated solar cell microstrip patch antennas  

SciTech Connect

The integration of microstrip patch antennas with photovoltaics has been proposed for applications in autonomous wireless communication systems located on building facades. Full integration was achieved using polycrystalline silicon solar cells as both antenna ground plane and direct current power generation in the same device. An overview of the proposed photovoltaic antenna designs is provided and the variation characterised of the electromagnetic properties of the device with temperature and solar radiation. Measurements for both copper and solar antennas are reported on three different commercial laminates with contrasting values for thermal coefficient of the dielectric constant. (author)

Roo-Ons, M.J.; Shynu, S.V.; Ammann, M.J. [Antenna and High Frequency Research Centre, School of Electronic and Communications Engineering, Dublin Institute of Technology (Ireland); Seredynski, M. [Institute of Heat Engineering, Warsaw University of Technology (Poland); McCormack, S.J. [Dept. of Civil, Structural and Environmental Engineering, Trinity College Dublin (Ireland); Norton, B. [Dublin Energy Lab., Focas Institute, Dublin Institute of Technology (Ireland)

2010-09-15

403

Heat pipe-based cooling systems for photovoltaic cells under concentrated solar radiation  

Microsoft Academic Search

Concentrating solar radiation onto photovoltaic solar cells does not generally produce a uniform distribution of solar radiation at the surface of the cells. In this work a unique profile for the reflecting surfaces has been developed such that the solar cells are evenly illuminated under any degree of concentration. Also introduced is a passive method based on thermosyphons which can

A. Akbarzadeh; T. Wadowski

1996-01-01

404

Titan: Photochemical Modeling and Production of Aerosols  

NASA Astrophysics Data System (ADS)

Photolysis of methane results in the synthesis of more complex hydrocarbons. The hydrocarbon chemistry inevitably leads to the formation of high molecular weight species, and eventually gives rise to the production of aerosols. We carried out a photochemical study in a one-dimensional model. The temperature profile is based on that recently acquired by the Cassini UVIS experiment. Only solar UV radiation was used to drive the chemistry. The modeled concentrations of hydrocarbons species (C2H2, C2H6, C2H4, and C4H2) are in general agreement with the Cassini measurements in the region below ˜800 km. Above this level, the observed concentrations of these hydrocarbon compounds show a much larger density scale height than that in the model. This implies (1) there is an additional energy source (e.g., precipitating electrons) driving the production of organic compounds at higher altitudes, and/or (2) large scale transport of photochemical products from regions that have been in the sun for longer duration. We also found that the most probable molecule for the production of the detached haze layer observed at ˜500 km is C4H2. This compound and related polyynes would condense near the temperature minimum at ˜600 km. Other plausible precursor molecules under investigation for producing the detached aerosol layer include C6H6 and PAH, and nitrile species. Estimates are made to relate the photochemical production rates to the size distribution and optical properties of the aerosol particles.

Yung, Y. L.; Liang, M. C.; Tinetti, G.; Shemansky, D.; West, R. A.; Tice, D.

2005-08-01

405

Results of the 1979 NASA/JPL Balloon Flight Solar Cell Calibration Program.  

National Technical Information Service (NTIS)

Calibration of solar cells to be used as reference standards in simulator testing of cells and arrays was accomplished. Thirty-eight modules were carried to an altitude of about 36 kilometers during the solar cell calibration balloon flight.

C. H. Seaman R. S. Weiss

1980-01-01

406

Field collapse due to band-tail charge in amorphous silicon solar cells.  

National Technical Information Service (NTIS)

It is common for the fill factor to decrease with increasing illumination intensity in hydrogenated amorphous silicon solar cells. This is especially critical for thicker solar cells, because the decrease is more severe than in thinner cells. Usually, the...

Q. Wang R. S. Crandall E. A. Schiff

1996-01-01

407

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

Microsoft Academic Search

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

Veronica Sholin

2008-01-01

408

Solar cell angle of incidence corrections  

NASA Astrophysics Data System (ADS)

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 degradation, particulate soiling, and background color. Only the first three are covered in this paper due to lack of sufficient data. The cosine correction is commonly used but is not sufficient when the incident angle is large. Fresnel reflection calculations require knowledge of the index of refraction of the coverglass front surface. The absolute index of refraction for the coverglass front surface was not known nor was it measured due to lack of funds. However, a value for the index of refraction was obtained by examining how the prediction errors varied with different assumed indices and selecting the best fit to the set of measured values. Corrections using front surface Fresnel reflection along with the cosine correction give very good predictive results when compared to measured data, except there is a definite trend away from predicted values at the larger incident angles. This trend could be related to edge effects and is illustrated by a use of a box plot of the errors and by plotting the deviation of the mean against incidence angle. The trend is for larger deviations at larger incidence angles and there may be a fourth order effect involved in the trend. A chi-squared test was used to determine if the measurement errors were normally distributed. At 10 degrees the chi-squared test failed, probably due to the very small numbers involved or a bias from the measurement procedure. All other angles showed a good fit to the normal distribution with increasing goodness-of-fit as the angles increased which reinforces the very small numbers hypothesis. The contributed data only went to 65 degrees from normal which prevented any firm conclusions about extreme angle effects although a trend in the right direction was seen. Measurement errors were estimated and found to be consistent with the conclusions that were drawn. A controlled experiment using coverglasses and cells from the same lots and extending to larger incidence angles would probably lead to further insight into the subject area.

Burger, Dale R.; Mueller, Robert L.

1995-10-01

409

Solar energy powered microbial fuel cell with a reversible bioelectrode.  

PubMed

The solar energy powered microbial fuel cell is an emerging technology for electricity generation via electrochemically active microorganisms fueled by solar energy via in situ photosynthesized metabolites from algae, cyanobacteria, or living higher plants. A general problem with microbial fuel cells is the pH membrane gradient which reduces cell voltage and power output. This problem is caused by acid production at the anode, alkaline production at the cathode, and the nonspecific proton exchange through the membrane. Here we report a solution for a new kind of solar energy powered microbial fuel cell via development of a reversible bioelectrode responsible for both biocatalyzed anodic and cathodic electron transfer. Anodic produced protons were used for the cathodic reduction reaction which held the formation of a pH membrane gradient. The microbial fuel cell continuously generated electricity and repeatedly reversed polarity dependent on aeration or solar energy exposure. Identified organisms within biocatalyzing biofilm of the reversible bioelectrode were algae, (cyano)bacteria and protozoa. These results encourage application of solar energy powered microbial fuel cells. PMID:19961218

Strik, David P B T B; Hamelers, Hubertus V M; Buisman, Cees J N

2010-01-01

410

Progress in InP solar cell research  

NASA Astrophysics Data System (ADS)

Progress, in the past year, in InP solar cell research is reviewed. Small area cells with AMO, total area efficiencies of 18.8 percent were produced by OMCVD and Ion Implantation. Larger area cells (2 and 4 sq cm) were processed on a production basis. One thousand of the 2 sq cm cells will be used to supply power to a small piggyback lunar orbiter scheduled for launch in February 1990. Laboratory tests of ITO/InP cells, under 10 MeV proton irradiation, indicate radiation resistance comparable to InP n/p homojunction cells. Computer modeling studies indicate that, for identical geometries and dopant concentrations, InP solar cells are significantly more radiation resistant than GaAs under 1 MeV electron irradiation. Additional computer modeling calculations were used to produce rectangular and circular InP concentrator cell designs for both the low concentration SLATS and higher concentration Cassegrainian Concentrators.

Weinberg, Irving; Brinker, David J.

411

Progress in InP solar cell research  

NASA Astrophysics Data System (ADS)

Progress, in the past year, in InP solar cell research is reviewed. Small area cells with AMO, total area efficiencies of 18.8 percent were produced by OMCVD and Ion Implantation. Larger area cells (2 and 4 sq cm) were processed on a production basis. One thousand of the 2 sq cm cells will be used to supply power to a small piggyback lunar orbiter scheduled for launch in February 1990. Laboratory tests of ITO/InP cells, under 10 MeV proton irradiation, indicate radiation resistance comparable to InP n/P homojunction cells. Computer modeling studies indicate that, for identical geometries and dopant concentrations, InP solar cells are significantly more radiation resistant than GaAs under 1 MeV electron irradiation. Additional computer modeling calculations were used to produce rectangular and circular InP concentrator cell designs for both the low concentration SLATS and higher concentration Cassegrainian Concentrators.

Weinberg, I.; Brinker, D. J.

412

Multilevel metallization for large area point-contact solar cells  

NASA Astrophysics Data System (ADS)

An analysis of the series resistances of different metallization schemes for large-area backside-contact (BC) solar cells is presented. The need for developing a multilevel metallization technology for such cells is demonstrated. The authors propose a new design for the metallization of BC cells that presents a series resistance independent of the cell size. The particular features required for such a multilevel interconnection are studied, and a process using anodic oxidation of aluminum is presented. BC silicon solar cells of 0.64 sq cm have been processed in this technology, resulting in 26.2 percent efficiencies at 10 W/sq cm (100 suns AM1.5, 25.5 deg C). Subsequent runs with a simplified process and a new cell design have given 27.3 percent efficiency cells. The cells have been soldered on alumina mounts. Results of thermal cycling are given.

Verlinden, P.; Swanson, R. M.; Sinton, R. A.; Kane, D. E.

413

Solar cells design for low and medium concentrating photovoltaic systems  

NASA Astrophysics Data System (ADS)

The solar cell is the key element of any CPV system, and its design plays an important role in enhancing the performance of the entire system. Special types of cells are required in the CPV systems capable of operating at high concentrations and elevated temperatures. These Concentrator solar cells differ significantly from the usual solar cells in the method of manufacture, the overall cell design and their performance. Systematic design and manufacture of the cell ensures better performance in a given CPV system. A number of factors come into play while designing the solar cell for a specific system these include concentration, cell material properties, expected operating temperature, shape, bus bar configuration and finger spacing. Most of these variables are decided on based on some rules of thumb and PC1D calculations. However, there is scope for design improvement and cell optimization by performing a detailed analysis based on the illumination profile incident on the cell. Recent studies demonstrated the use of Finite element method to analyze the electrical behavior of PV cell under the influence of arbitrarily chosen illumination flux profiles. This study outlines a methodology and analysis procedure while performing a case study of a CPV system under development having a non-uniform illumination profile towards the exit of the concentrator. The LCPV system chosen is the Photovoltaic Facades of Reduced Costs Incorporating Devices with Optically Concentrating Elements (PRIDE) concentrator made of dielectric material. A coupled optical, thermal and electrical analysis is performed on the system to demonstrate the method useful in designing solar cells for low and medium concentrations.

Baig, Hasan; Heasman, Keith C.; Sarmah, Nabin; Mallick, Tapas

2012-10-01

414

Photochemical Models for Mars' Upper Atmosphere and Ionosphere at Low, Medium, and High Solar Activity: Implications for H2, D, and Evolution of Water  

NASA Astrophysics Data System (ADS)

Self-consistent models for 11 neutral and 18 ion species from 80 to 300 km on Mars have been developed by solving the continuity equations including ambipolar diffusion for ions. The models were calculated for the conditions of the HST, FUSE, and Mariner 6, 7 observations of D, H2, and H, respectively, when solar activity index was 25, 61, and 88 on Mars orbit, respectively. Special care was taken to simulate the processes of H2 and HD dissociation in the reactions with CO2+, O+, CO+, N2+, N+, Ar+, O(1D), and by photoelectrons. Thermal and nonthermal escape velocities were used as the upper boundary conditions for H2, H, HD, D, and He. The calculated ion density profiles at various solar activity and the column reaction rates provide complete quantitative information for behavior of each ion, its formation and loss. The HCO+ ion is abundant in Mars' ionosphere because it is a final product of many reactions of other ions with H2 and does not react with neutral species. The H2 and D mixing ratios of 15 ppm and 11 ppb chosen to fit the FUSE and HST observations of H2 and D, respectively, result in (HD/H2)/(HDO/H2O) = 0.41. This value agrees with the depletion of D in H2 because of the smaller HDO photolysis cross section, the preferential condensation of HDO above the hygropause, and the fractionation in chemical reactions that result in the formation of H2. Therefore the controversial problem of deuterium fractionation is solved throughout the atmosphere. Isotope fractionation factor for hydrogen escape is equal to 0.055, 0.082, and 0.167 for low, medium, and high solar activity, respectively, and the solar cycle mean value is 0.105. The polar caps shrink or dissappear at high obliquity, and water in the polar caps is in isotopic equilibrium with the atmospheric water. Using the water amount of 14 m in the polar caps, the fractionation factor, the present D/H ratio and that at the end of hydrodynamic escape (5.5 and 1.9 times the terrestrial ratio, respectively), the calculated loss of water for the last 3.8 Byr is equal to a global ocean 30 m deep. Delivery of water by comets was ?0.5 m in that period and could not significantly affect the D/H ratio. The existence of liquid ocean on early Mars is not sufficient to drive hydrodynamic escape, and that of the initially accreted H2 and H2 released in the reaction Fe + H2O -> FeO + H2 is more probable. Using the known fractionation factor of 0.8 for hydrodynamic escape, the total loss of water in hydrodynamic escape is equivalent of an ocean of more than 1.3 km deep. This means that the initial amount of water on Mars exceeded that on Earth scaled to the mass and size of Mars.

Krasnopolsky, V. A.

2002-05-01

415

GAAS shallow-homojunction solar cells. Final report  

SciTech Connect

The feasibility of fabricating space resistant, high efficiency, light weight, low cost GaAs shallow homojunction solar cells for space application is investigated. The material preparation of ultrathin GaAs single crystal layers, and the fabrication of efficient GaAs solar cells on bulk GaAs substrates are discussed. Considerable progress was made in both areas, and conversion efficiency about 16% AMO was obtained using anodic oxide as a single layer antireflection coating. A computer design shows that even better cells can be obtained with double layer antireflection coating. Ultrathin, high efficiency solar cells were obtained from GaAs films prepared by the CLEFT process, with conversion efficiency as high as 17% at AMI from a 10 micrometers thick GaAs film. A organometallic CVD was designed and constructed.

Fan, J.C.C.

1981-06-01

416

Laminated photovoltaic modules using back-contact solar cells  

DOEpatents

Photovoltaic modules which comprise back-contact solar cells, such as back-contact crystalline silicon solar cells, positioned atop electrically conductive circuit elements affixed to a planar support so that a circuit capable of generating electric power is created. The modules are encapsulated using encapsulant materials such as EVA which are commonly used in photovoltaic module manufacture. The module designs allow multiple cells to be electrically connected in a single encapsulation step rather than by sequential soldering which characterizes the currently used commercial practices.

Gee, James M. (Albuquerque, NM); Garrett, Stephen E. (Albuquerque, NM); Morgan, William P. (Albuquerque, NM); Worobey, Walter (Albuquerque, NM)

1999-09-14

417

Development and fabrication of a solar cell junction processing system  

NASA Astrophysics Data System (ADS)

A solar cell junction processing system was developed and fabricated. A pulsed electron beam for the four inch wafers is being assembled and tested, wafers were successfully pulsed, and solar cells fabricated. Assembly of the transport locks is completed. The transport was operated successfully but not with sufficient reproducibility. An experiment test facility to examine potential scaleup problems associated with the proposed ion implanter design was constructed and operated. Cells were implanted and found to have efficiency identical to the normal Spire implant process.

Bunker, S.

1981-10-01

418

Electroless copper contacts for low concentration silicon solar cells  

NASA Astrophysics Data System (ADS)

The purpose of this work was to form highly conductive and low cost copper contacts on shallow and hence optically thin p-n junctions (<0.4?m deep) on a randomly textured solar cells for low concentration PV (LCPV) module. At first, window formation process in SiNx by femtosecond UV laser pulse ablation on the textured surface was introduced. Then nickel silicide contacts were formed and subsequent contact thickening was performed by electroless copper plating in an industrially feasible way. Characteristics of finished solar cells were investigated in this work. The cells were successfully implemented into the low concentration (C=15x) PV module.

Janušonis, Julius; Galdikas, Algirdas; Juzumas, Valdemaras; Jaramin?, Lina; Lukštaraupis, Tomas; Andrijauskas, Darius; Janušonien?, Vida; Janušonis, Darius; Ulbikas, Juras

2012-10-01

419

Effects of Photochemical Oxidants on Plants.  

National Technical Information Service (NTIS)

Photochemical oxidants are found in 'photochemical smog' which is a complex mixture of primary and secondary air pollutants. The photochemical oxidants are secondary air pollutants formed by the action of sunlight on nitrogen oxides and reactive hydrocarb...

R. Guderian D. T. Tingey R. Rabe

1984-01-01

420

New developments in CIGS thin-film solar cell technology  

Microsoft Academic Search

Thin-film solar modules based on Cu(In,Ga)Se\\/sub 2\\/ (ClGS) are on the way to mass production. ZSW is operating a line for 0.3 m \\/spl times\\/ 0.3 m modules in which all process steps - from glass cleaning to module encapsulation - are being developed. Especially new materials and processes are transferred from cells to the module level. In Wuerth Solar's

Michael Powalla; B. Dimmler

2003-01-01

421

Integration of Microstrip Patch Antenna With Polycrystalline Silicon Solar Cell  

Microsoft Academic Search

The implementation of a polycrystalline silicon solar cell as a microwave groundplane in a low-profile, reduced-footprint microstrip patch antenna design for autonomous communication applications is reported. The effects on the antenna\\/solar performances due to the integration, different electrical conductivities in the silicon layer and variation in incident light intensity are investigated. The antenna sensitivity to the orientation of the anisotropic

S. V. Shynu; Maria Jose Roo Ons; Patrick McEvoy; Max J. Ammann; Sarah J. McCormack; Brian Norton

2009-01-01

422

Integration of Microstrip Patch Antennas with Polycrystalline Silicon Solar Cells  

Microsoft Academic Search

The implementation of a polycrystalline silicon solar cell as a microwave groundplane in a low-profile, reduced-footprint microstrip patch antenna design for autonomous communication applications is reported. The effects on the antenna\\/solar performances due to the integration, different electrical conductivities in the silicon layer and variation in incident light intensity are investigated. The antenna sensitivity to the orientation of the anisotropic

S. V. Shynu; M. Roo Ons; Max Ammann; Sarah McCormack; Brian Norton

2009-01-01

423

Silicon nanocrystals as light converter for solar cells  

Microsoft Academic Search

In this work, we investigate the potential use of silicon nanocrystals (Si-nc) into photovoltaics technology as one possible way to increase the silicon solar efficiency at low cost. The Si-nc were prepared ex situ (pulverizing of electrochemical etched porous silicon), embedded into spin-on-glass antireflecting SiO2 based solution and then spun onto standard silicon solar cells. The Si-nc\\/SiO2 layer serves as

V. Švr?ek; A. Slaoui; J.-C. Muller

2004-01-01

424

Characterization of CdSe Nanocrystals for Hybrid Solar Cells  

Microsoft Academic Search

Hybrid solar cells have attracted considerable attention in recent years due to their high thermal and chemical stability, light weight, high carrier mobility, and low cost. The active layer of cadmium selenide (CdSe) nanoparticles- poly(3-hexylthiophene) (P3HT) is optimized in terms of their mass ratio and microstructure by using absorption and scanning electron microscope (SEM). The active layer of hybrid solar

Virendra Kumar Verma; Yashvendra Singh; Ram Narayan Chauhan; R. S. Anand; Jitendra Kumar

2010-01-01

425

Nanostructured solar cells employ wide-band-gap  

Microsoft Academic Search

The solar-electric conversion efficiency of traditional semicon- ductor solar cells is limited by a fundamental trade-off between the current generated by photon absorption and the operating voltage. Photons with energies below the semiconductor band gap pass straight through the device and do not contribute to the photocurrent. High-energy photons can be absorbed, but the resulting electrons are collected and extracted

Roger Welser

426

High-efficiency space and terrestrial multijunction solar cells through bandgap control in cell structures  

Microsoft Academic Search

Using the energy bandgap of semiconductors as a design parameter is critically important for achieving the highest efficiency multijunction solar cells. The bandgaps of lattice-matched semiconductors that are most convenient to use are rarely those which would result in the highest theoretical efficiency. For both the space and terrestrial solar spectra, the efficiency of 3-junction GaInP\\/GaAs\\/Ge solar cells can be

Richard R. King; C. M. Fetzer; Peter C. Colter; Ken M. Edmondson; J. H. Ermer; Hector L. Cotal; Hojun Yoon; Alex P. Stavrides; Geoff Kinsey; Dimitri D. Krut; N. H. Karam

2002-01-01

427

The Use of Fep Teflon in Solar Cell Cover Technology.  

National Technical Information Service (NTIS)

FEP plastic film was used as a cover and as an adhesive to bond cover glasses to silicon solar cells. Various anti-reflective coatings were applied to cells and subsequently covered with FEP. Short circuit currents were measured before and after applicati...

G. A. Mazaris J. D. Broder

1973-01-01

428

Simplified edge isolation of buried contact solar cells  

Microsoft Academic Search

The aim of this work is to implement simple edge isolation techniques in buried contact solar cell (BCSC) process by preserving the active cell area. Here we present results of two simplified edge isolation techniques for BCSC and they are compared with the standard process incorporating mechanical edge isolation using a dicing saw. The first technique is chemical wet etching

Jayaprasad Arumughan; Thomas Pernau; Alexander Hauser; Ihor Melnyk

2005-01-01

429

The performance of advanced solar cells for interplanetary missions  

Microsoft Academic Search

Recent advances in space solar cell technology have produced substantial increases in Air Mass Zero (AM0) efficiency. Since these cells have been developed primarily for Earth orbiting missions, little is known of their behavior at distances far from the Sun. In order to better define the photovoltaic performance of arrays for deep space missions, JPL has completed initial measurements on

Paul M. Stella; Gregory L. Davis; Robert L. Mueller; Dmitri D. Krut; David J. Brinker; David A. Scheiman

2000-01-01

430

Radiation Effects on Multi-Junction Solar Cells.  

National Technical Information Service (NTIS)

The GaInP2/GaAs/Ge monolithic high efficiency triple junction cell is the state of the art multijunction solar cell for space applications. Numerous labs have undertaken investigation into the stability of GaInP2/GaAs/Ge in response to electron radiation....

T. L. Fifer

2001-01-01

431

Development of a Cadmium Selenide Thin Film Solar Cell.  

National Technical Information Service (NTIS)

A CdSe MIS thin film solar cell was developed. Fourteen materials were studied with regard to their suitability as I-layers. Two these compounds, i.e., ZnSe and Sb2Se3, give cells with relatively high photovoltage and high photocurrent. The preparation pr...

D. Bonnet

1979-01-01

432

Development of a Cadmium Selenide Thin Film Solar Cell.  

National Technical Information Service (NTIS)

A project aimed at developing a CdSe MIS thin film solar cell was conducted. Fourteen materials were studied with regard to their suitability as I-layers. Two of these compounds, i.e., ZnSe and SbSe, were found to result in cells with relatively high phot...

D. Bonnet

1979-01-01

433

An automatable integrated thin film solar cell array  

Microsoft Academic Search

A description is presented of a new integrated array of thin film solar cells which can be produced by means of continuous automatic fabrication techniques and which offers major advantages in cost and operational reliability. In the first step of the fabrication procedure negative electrodes are formed on an insulating substrate. The negative electrodes define the individual cells. In the

W. J. Biter; F. A. Shirland

1976-01-01

434

Solar-wind hybrid power for rural Indian cell sites  

Microsoft Academic Search

Rapid expansion of rural cell phone subscriber base in India is facing some tough challenges in getting the stable back up power for cell sites. Grid power availability is very poor and use of diesel generator is turning out to be expensive with heavy fuel and transportation costs. Use of alternative energy provides a long term viable solution. Solar-wind hybrid

A. Naikodi

2010-01-01

435

Radiation Effects in Heteroepitaxial InP Solar Cells.  

National Technical Information Service (NTIS)

Heteroepitaxial InP solar cells, with GaAs substrates, were irradiated by 0.5 and 3 MeV protons and their performance, temperature dependency, and carrier removal rates determined as a function of fluence. The radiation resistance of the present cells was...

I. Weinberg H. B. Curtis C. K. Swartz D. J. Brinker C. Vargas-Aburto

1993-01-01

436

A model to determine financial indicators for organic solar cells  

SciTech Connect

Organic solar cells are an emerging photovoltaic technology that is inexpensive and easy to manufacture, despite low efficiency and stability. A model, named TEEOS (Technical and Economic Evaluator for Organic Solar), is presented that evaluates organic solar cells for various solar energy applications in different geographic locations, in terms of two financial indicators, payback period and net present value (NPV). TEEOS uses SMARTS2 software to estimate broadband (280-4000 nm) spectral irradiance data and with the use of a cloud modification factor, predicts hourly irradiation in the absence of actual broadband irradiance data, which is scarce for most urban locations. By using the avoided cost of electricity, annual savings are calculated which produce the financial indicators. It is hoped that these financial indicators can help guide certain technical decisions regarding the direction of research for organic solar cells, for example, increasing efficiency or increasing the absorptive wavelength range. A sample calculation using solar hats is shown to be uneconomical, but a good example of large-scale organic PV production. (author)

Powell, Colin; Bender, Timothy; Lawryshyn, Yuri [Department of Chemical Engineering and Applied Chemistry, Faculty of Engineering and Applied Science, University of Toronto, 200 College Street, Toronto, Ont. (Canada)

2009-11-15

437

Photochemical cutting of fabrics  

DOEpatents

Apparatus for the cutting of garment patterns from one or more layers of fabric. A laser capable of producing laser light at an ultraviolet wavelength is utilized to shine light through a pattern, such as a holographic phase filter, and through a lens onto the one or more layers of fabric. The ultraviolet laser light causes rapid photochemical decomposition of the one or more layers of fabric, but only along the pattern. The balance of the fabric of the one or more layers of fabric is undamaged.

Piltch, Martin S. (Los Alamos, NM)

1994-01-01

438

Photochemical cutting of fabrics  

SciTech Connect

Apparatus is described for the cutting of garment patterns from one or more layers of fabric. A laser capable of producing laser light at an ultraviolet wavelength is utilized to shine light through a pattern, such as a holographic phase filter, and through a lens onto the one or more layers of fabric. The ultraviolet laser light causes rapid photochemical decomposition of the one or more layers of fabric, but only along the pattern. The balance of the fabric of the one or more layers of fabric is undamaged. 1 fig.

Piltch, M.S.

1994-11-22

439

Dye-sensitized solar tubes: A new solar cell design for efficient current collection and improved cell sealing  

Microsoft Academic Search

A dye-sensitized solar cell (DSSC) fabricated inside a glass tube to form a dye-sensitized solar tube (DSST) is presented. We developed the synthesis of Fluorine-doped Tin oxide (FTO) with a high optical transmittance and low sheet resistance, which was deposited inside a glass tube by spray pyrolysis. The FTO was covered with a mesoporous TiO2 film using electrophoretic deposition (EPD).

Zion Tachan; Sven Rühle; Arie Zaban

2010-01-01

440

Concentrator solar cell array technology flight experiment  

Microsoft Academic Search

A flight experiment has been planned to study the suitability of a new concentrator solar array technology for satellite applications. This paper briefly describes the design and testing of the experiment. By the end of March 2002, Space Systems\\/Loral (SS\\/L) completed the testing of the flight coupon panel under various space environment conditions. The experiment is under integration and will

R. K. Jain; Yu Nang Wong; J. Kesapradist; G. van Ommering; M. Eskenazi

2002-01-01

441

Anomalous charge storage exponents of organic bulk heterojunction solar cells.  

NASA Astrophysics Data System (ADS)

Organic bulk heterojunction (BHJ) devices are increasingly being researched for low cost solar energy conversion. The efficiency of such solar cells is dictated by various recombination processes involved. While it is well known that the ideality factor and hence the charge storage exponents of conventional PN junction diodes are influenced by the recombination processes, the same aspects are not so well understood for organic solar cells. While dark currents of such devices typically show an ideality factor of 1 (after correcting for shunt resistance effects, if any), surprisingly, a wide range of charge storage exponents for such devices are reported in literature alluding to apparent concentration dependence for bi-molecular recombination rates. In this manuscript we critically analyze the role of bi-molecular recombination processes on charge storage exponents of organic solar cells. Our results indicate that the charge storage exponents are fundamentally influenced by the electrostatics and recombination processes and can be correlated to the dark current ideality factors. We believe that our findings are novel, and advance the state-of the art understanding on various recombination processes that dictate the performance limits of organic solar cells.

Nair, Pradeep; Dwivedi, Raaz; Kumar, Goutam

2013-03-01

442

Light harvesting enhancement in solar cells with quasicrystalline plasmonic structures.  

PubMed

Solar cells are important in the area of renewable energies. Since it is expensive to produce solar-grade silicon [Electrochem. Soc. Interface 17, 30 (2008)], especially thin-film solar cells are interesting. However, the efficiency of such solar cells is low. Therefore, it is important to increase the efficiency. The group of Polman has shown that a periodic arrangement of metal particles is able to enhance the absorbance of light [Nano Lett. 11, 1760 (2011)]. However, a quasicrystalline arrangement of the metal particles is expected to enhance the light absorbance independent of the incident polar and azimuthal angles due to the more isotropic photonic bandstructure. In this paper, we compare the absorption enhancement of a quasiperiodic photonic crystal to that of a periodic photonic crystal. We indeed find that the absorption enhancement for the quasicrystalline arrangement shows such an isotropic behavior. This implies that the absorption efficiency of the solar cell is relatively constant during the course of the day as well as the year. This is particularly important with respect to power distribution, power storage requirements, and the stability of the electric grid upon massive use of renewable energy. PMID:24104423

Bauer, Christina; Giessen, Harald

2013-05-01

443

New approaches for high-efficiency solar cells. Final report  

SciTech Connect

This report summarizes the activities carried out in this subcontract. These activities cover, first the atomic layer epitaxy (ALE) growth of GaAs, AlGaAs and InGaP at fairly low growth temperatures. This was followed by using ALE to achieve high levels of doping both n-type and p-type required for tunnel junctions (Tj) in the cascade solar cell structures. Then the authors studied the properties of AlGaAs/InGaP and AlGaAs/GaAs tunnel junctions and their performances at different growth conditions. This is followed by the use of these tunnel junctions in stacked solar cell structures. The effect of these tunnel junctions on the performance of stacked solar cells was studied at different temperatures and different solar fluences. Finally, the authors studied the effect of different types of black surface fields (BSF), both p/n and n/p GaInP solar cell structures, and their potential for window layer applications. Parts of these activities were carried in close cooperation with Dr. Mike Timmons of the Research Triangle Institute.

Bedair, S.M.; El-Masry, N.A. [North Carolina State Univ., Raleigh, NC (United States)

1997-12-01

444

Ultrathin and lightweight organic solar cells with high flexibility.  

PubMed

Application-specific requirements for future lighting, displays and photovoltaics will include large-area, low-weight and mechanical resilience for dual-purpose uses such as electronic skin, textiles and surface conforming foils. Here we demonstrate polymer-based photovoltaic devices on plastic foil substrates less than 2 ?m thick, with equal power conversion efficiency to their glass-based counterparts. They can reversibly withstand extreme mechanical deformation and have unprecedented solar cell-specific weight. Instead of a single bend, we form a random network of folds within the device area. The processing methods are standard, so the same weight and flexibility should be achievable in light emitting diodes, capacitors and transistors to fully realize ultrathin organic electronics. These ultrathin organic solar cells are over ten times thinner, lighter and more flexible than any other solar cell of any technology to date. PMID:22473014

Kaltenbrunner, Martin; White, Matthew S; G?owacki, Eric D; Sekitani, Tsuyoshi; Someya, Takao; Sariciftci, Niyazi Serdar; Bauer, Siegfried

2012-04-03

445

Ultrathin and lightweight organic solar cells with high flexibility  

NASA Astrophysics Data System (ADS)

Application-specific requirements for future lighting, displays and photovoltaics will include large-area, low-weight and mechanical resilience for dual-purpose uses such as electronic skin, textiles and surface conforming foils. Here we demonstrate polymer-based photovoltaic devices on plastic foil substrates less than 2??m thick, with equal power conversion efficiency to their glass-based counterparts. They can reversibly withstand extreme mechanical deformation and have unprecedented solar cell-specific weight. Instead of a single bend, we form a random network of folds within the device area. The processing methods are standard, so the same weight and flexibility should be achievable in light emitting diodes, capacitors and transistors to fully realize ultrathin organic electronics. These ultrathin organic solar cells are over ten times thinner, lighter and more flexible than any other solar cell of any technology to date.

Kaltenbrunner, Martin; White, Matthew S.; G?owacki, Eric D.; Sekitani, Tsuyoshi; Someya, Takao; Sariciftci, Niyazi Serdar; Bauer, Siegfried

2012-04-01

446

Ultrathin and lightweight organic solar cells with high flexibility  

PubMed Central

Application-specific requirements for future lighting, displays and photovoltaics will include large-area, low-weight and mechanical resilience for dual-purpose uses such as electronic skin, textiles and surface conforming foils. Here we demonstrate polymer-based photovoltaic devices on plastic foil substrates less than 2??m thick, with equal power conversion efficiency to their glass-based counterparts. They can reversibly withstand extreme mechanical deformation and have unprecedented solar cell-specific weight. Instead of a single bend, we form a random network of folds within the device area. The processing methods are standard, so the same weight and flexibility should be achievable in light emitting diodes, capacitors and transistors to fully realize ultrathin organic electronics. These ultrathin organic solar cells are over ten times thinner, lighter and more flexible than any other solar cell of any technology to date.

Kaltenbrunner, Martin; White, Matthew S.; Glowacki, Eric D.; Sekitani, Tsuyoshi; Someya, Takao; Sariciftci, Niyazi Serdar; Bauer, Siegfried

2012-01-01

447

Visualizing charge separation in bulk heterojunction organic solar cells  

NASA Astrophysics Data System (ADS)

Solar cells based on conjugated polymer and fullerene blends have been developed as a low-cost alternative to silicon. For efficient solar cells, electron-hole pairs must separate into free mobile charges that can be extracted in high yield. We still lack good understanding of how, why and when carriers separate against the Coulomb attraction. Here we visualize the charge separation process in bulk heterojunction solar cells by directly measuring charge carrier drift in a polymer:fullerene blend with ultrafast time resolution. We show that initially only closely separated (<1?nm) charge pairs are created and they separate by several nanometres during the first several picoseconds. Charge pairs overcome Coulomb attraction and form free carriers on a subnanosecond time scale. Numerical simulations complementing the experimental data show that fast three-dimensional charge diffusion within an energetically disordered medium, increasing the entropy of the system, is sufficient to drive the charge separation process.

Vithanage, D. Amarasinghe; Devižis, A.; Abramavi?ius, V.; Infahsaeng, Y.; Abramavi?ius, D.; MacKenzie, R. C. I.; Keivanidis, P. E.; Yartsev, A.; Hertel, D.; Nelson, J.; Sundström, V.; Gulbinas, V.

2013-08-01

448

Solar Cells for High Temperature Environments in Space  

NASA Astrophysics Data System (ADS)

Future NASA missions into regions close to the sun will require power systems to operate in high temperature, high light-intensity environments. Some of the missions are: *Solar Probe Plus *Mercury probes *Venus probes Approaches to solar array design include developing improved high-temperature solar cells, reducing incident intensity to limit temperature, and use of cooling to minimize the temperature. Each of these missions has different challenges. Solar Probe Plus, a mission to the outer corona of the sun, will operate from 1 AU inward to 9.5 solar radii from the sun, nearly three orders of magnitude in incident intensity. Probes to the surface of Mercury experience a solar intensity of 10 kW/m^2 with temperature ranging from 425^oC at noon to -175^oC at night; while Mercury orbital missions are subject to incident solar radiation, reflected sunlight, and thermal IR radiated from the planet's surface. Venus presents the greatest challenge to photovoltaic operation, with surface temperature of 450^oC, low intensity sunlight, and a corrosive environment.

Landis, Geoffrey

2010-04-01

449

Efficient Tandem Polymer Solar Cells Fabricated by All-Solution Processing  

Microsoft Academic Search

Tandem solar cells, in which two solar cells with different absorption characteristics are linked to use a wider range of the solar spectrum, were fabricated with each layer processed from solution with the use of bulk heterojunction materials comprising semiconducting polymers and fullerene derivatives. A transparent titanium oxide (TiOx) layer separates and connects the front cell and the back cell.

Jin Young Kim; Kwanghee Lee; Nelson E. Coates; Daniel Moses; Thuc-Quyen Nguyen; Mark Dante; Alan J. Heeger

2007-01-01

450

Comparison of Dye-Sensitized Rutile- and Anatase-Based TiO2 Solar Cells  

SciTech Connect

The objective of this work is to develop and optimize the new dye-sensitized solar cell technology. In view of the infancy of rutile material development for solar cells, the PV response of the dye-sensitized rutile-based solar cell is remarkably close to that of the anatase-based cell.

Park, N. G.; van de Lagemaat, J.; Frank, A. J.

2000-01-01

451

A V-grooved GaAs solar cell  

SciTech Connect

V-grooved GaAs solar cells promise the benefits of improved optical coupling, higher short-circuit current, and increased tolerance to particle radiation compared to planar cells. A GaAs homojunction cell was fabricated by etching a V-groove pattern into an n epilayer (2.1 x 10 to the 17th power per cu cm) grown by metalorganic chemical vapor deposition (MOCVD) on an n+ substrate (2.8 x 10 to the 18th power per cu cm) and then depositing and MOCVD p epilayer (4.2 x 10 to the 18th power per cu cm). Reflectivity measurements on cells with and without an antireflective coating confirm the expected decrease in reluctance of the microgrooved cell compared to the planar structure. The short circuit current of the V-grooved solar cell was 13 percent higher than that of the planar control.

Bailey, S.G.; Fatemi, N.S.; Landis, G.A.; Wilt, D.M.; Thomas, R.D.; Arrison, A.

1988-01-01

452

Silicon heterojunction solar cell and crystallization of amorphous silicon  

NASA Astrophysics Data System (ADS)

The rapid growth of photovoltaics in the past decade brings on the soaring price and demand for crystalline silicon. Hence it becomes necessary and also profitable to develop solar cells with over 20% efficiency, using thin (˜100mum) silicon wafers. In this respect, diffused junction cells are not the best choice, since the inescapable heating in the diffusion process not only makes it hard to handle thin wafers, but also reduces carriers' bulk lifetime and impairs the crystal quality of the substrate, which could lower cell efficiency. An alternative is the heterojunction cells, such as amorphous silicon/crystalline silicon heterojunction (SHJ) solar cell, where the emitter layer can be grown at low temperature (<200°C). In first part of this dissertation, I will introduce our work on front-junction SHJ solar cell, including the importance of intrinsic buffer layer; the discussion on the often observed anomalous "S"-shaped J-V curve (low fill factor) by using band diagram analysis; the surface passivation quality of intrinsic buffer and its relationship to the performance of front-junction SHJ cells. Although the a-Si:H is found to help to achieve high efficiency in c-Si heterojuntion solar cells, it also absorbs short wavelength (<600 nm) light, leading to non-ideal blue response and lower short circuit currents (JSC) in the front-junction SHJ cells. Considering this, heterojunction with both a-Si:H emitter and base contact on the back side in an interdigitated pattern, i.e. interdigitated back contact silicon heterojunction (IBC-SHJ) solar cell, is developed. This dissertation will show our progress in developing IBC-SHJ solar cells, including the structure design; device fabrication and characterization; two dimensional simulation by using simulator Sentaurus Device; some special features of IBC-SHJ solar cells; and performance of IBC-SHJ cells without and with back surface buffer layers. Another trend for solar cell industry is thin film solar cells, since they use less materials resulting in lower cost. Polycrystalline silicon (poly-Si) is one promising thin-film material. It has the potential advantages to not only retain the performance and stability of c-Si, but also use the well established manufacturing techniques on thin-film. One of the main difficulties of poly-Si thin-film solar cells is growing large-grained poly-Si films (grain sizes comparable to the film thickness of micrometers) onto foreign substrates. Aluminum-induced crystallization (AIC) is one technique that has been developed to transform the amorphous Si to large-grain poly-Si. In this dissertation, our systematic studies of AIC samples with different stack structures, with and without interface oxide layer, annealed both below and above eutectic temperature will be introduced, and a phenomenological model will be proposed to explain the experimental results.

Lu, Meijun

453

First principles modeling of panchromatic dyes for solar cells applications.  

NASA Astrophysics Data System (ADS)

The state-of-the-art dye in Gr"atzel solar cells, N719, exhibits a total solar-to-electric conversion efficiency of 11.2%. However, it severely lacks absorption in the red and the near infrared regions of the electromagnetic spectrum, which represent more than 70% of the solar radiation spectrum. Using calculations from first principles in the time-dependent domain, we have studied the electronic and optical response of a novel class of panchromatic sensitizers that can harvest solar energy efficiently across the visible and near infrared regions, which have been recently synthesized [A. El-Shafei, M. Hussain, A. Atiq, A. Islam, and L. Han, J. Mater. Chem. 22, 24048 (2012)]. Our calculations show that, by tuning the properties of antenna groups, one can achieve a substantial improvement of the optical properties.

di Felice, Rosa; Calzolari, Arrigo; Dong, Rui; Buongiorno Nardelli, Marco

2013-03-01

454

Proton irradiated heteroepitaxial InP solar cells  

Microsoft Academic Search

Heteroepitaxial InP solar cells, processed using GaAs substrates, were proton irradiated over the energy range from 0.2 to 10 MeV. Results for carrier removal, cell performance and minority carrier diffusion length were found to be separable into either dislocation dominated or energy dependent categories. High dislocation densities were dominant in determining low pre-irradiation minority carrier diffusion lengths and cell efficiencies.

I. Weinberg; R. K. Jain; C. K. Swartza; H. B. Curtis; D. J. Brinker; C. Vargas-Aburtob; P. J. Drevinsky

1993-01-01

455

Dye-Sensitized Solar Cell Utilizing Electrostatic Inkjet  

NASA Astrophysics Data System (ADS)

Solar cell is one of the key technologies in this century because this has possibility to clear energy problems. We tried to pattern good titania layer of dye-sensitized solar cell (DSC) utilizing electrostatic inkjet. The electrostatic inkjet has good merit; that is ability to eject highly viscous liquid. We applied the merit for patterning titania paste on fluorine-doped tin oxide (FTO) glass. In this paper, we investigated fundamental characteristics to pattern titania layer on FTO glass because efficiency depends on thickness of titania layer.

Umezu, Shinjiro; Kunugi, Yoshihito; Ohmori, Hitoshi

2013-05-01

456

Disordered photonic structures for light harvesting in solar cells.  

PubMed

The effect of periodic and disordered photonic structures on the absorption efficiency of amorphous and crystalline Silicon thin-film solar cells is investigated numerically. We show that disordered patterns possessing a short-range correlation in the position of the holes yield comparable, or even superior, absorption enhancements than periodic (photonic crystal) patterns. This work provides clear evidence that non-deterministic photonic structures represent a viable alternative strategy for photon management in thin-film solar cells, thereby opening the route towards more efficient and potentially cheaper photovoltaic technologies. PMID:24104434

Pratesi, Filippo; Burresi, Matteo; Riboli, Francesco; Vynck, Kevin; Wiersma, Diederik S

2013-05-01

457

[Improvement of the power conversion efficiency in organic solar cells].  

PubMed

Energy is most important issue in the world now because the chemical energy (oil, natural gas, coal et al) is on the edge of depleting. Many Countries are now paying attention to the use of sun power. Photovoltaic device is the most important way to make use of sun energy. Organic solar cell is one promising kind of photovoltaic device, though it's low power conversion efficiency hampers its commercialization. This paper briefly reviewed two ways to improve the power conversion efficiency of organic solar cells and pointed out the unsolved problems. PMID:21800554

Mu, Li-ping; Yuan, Dan; Huan, Min; Chen, Zhi-jian; Xiao, Li-xin; Qu, Bo; Gong, Qi-huang

2011-05-01

458

Efficient laser textured nanocrystalline silicon-polymer bilayer solar cells  

NASA Astrophysics Data System (ADS)

Excimer laser textured thin film silicon and poly(2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylenevinylene bilayer solar cells are fabricated and characterized with air mass 1.5 simulated solar irradiation. The polymer layer increases the light harvesting capability of the cell and increases the shunt resistance while increasing open circuit voltage. The highest efficiency of 0.87% for the thin film silicon/polymer bilayer device is observed due to enhanced charge collection resulting from the inclusion of the polymer layer. Generation of charge carriers is proposed to be occurring mainly in the silicon layer and charge transport is explained using an energy band diagram.

Adikaari, A. A. D. T.; Dissanayake, D. M. N. M.; Hatton, R. A.; Silva, S. R. P.

2007-05-01

459

3D photonic crystals for photon management in solar cells  

NASA Astrophysics Data System (ADS)

Photon management is a key component in the development of efficient solar cells. Especially light-trapping concepts have a high potential to realize enhanced efficiencies. Here, we give an overview over several light trapping concepts for photon management in solar cells. These include basic as well as advanced light-trapping concepts. The theoretical limits of light path enhancement of the different concepts are given and experimental work on these topics is presented. The potential of 3D photonic crystals is discussed in the context of the corresponding approaches as well.

Schweizer, S. L.; Sprafke, A. N.; Wehrspohn, R. B.

2013-09-01

460

Process Development for High Voc CdTe Solar Cells  

SciTech Connect

This is a cumulative and final report for Phases I, II and III of this NREL funded project (subcontract # XXL-5-44205-10). The main research activities of this project focused on the open-circuit voltage of the CdTe thin film solar cells. Although, thin film CdTe continues to be one of the leading materials for large-scale cost-effective production of photovoltaics, the efficiency of the CdTe solar cells have been stagnant for the last few years. This report describes and summarizes the results for this 3-year research project.

Ferekides, C. S.; Morel, D. L.

2011-05-01

461

Fabrication of solar cells with counter doping prevention  

DOEpatents

A solar cell fabrication process includes printing of dopant sources over a polysilicon layer over backside of a solar cell substrate. The dopant sources are cured to diffuse dopants from the dopant sources into the polysilicon layer to form diffusion regions, and to crosslink the dopant sources to make them resistant to a subsequently performed texturing process. To prevent counter doping, dopants from one of the dopant sources are prevented from outgassing and diffusing into the other dopant source. For example, phosphorus from an N-type dopant source is prevented from diffusing to a P-type dopant source comprising boron.

Dennis, Timothy D; Li, Bo; Cousins, Peter John

2013-02-19

462

Efficient polymer nanocrystal hybrid solar cells by improved nanocrystal composition  

Microsoft Academic Search

We demonstrate the importance of the nanocrystal surface treatment and the inorganic composition for hybrid solar cells. Mixtures of CdSe nanorods and CdSe quantum dots integrated in hybrid solar cells together with the conjugated polymer poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b']-dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT) perform better than nanorod and quantum dot only based devices. In addition larger sized quantum dots show a similar improvement after integration in

Yunfei Zhou; Michael Eck; Cong Men; Frank Rauscher; Phenwisa Niyamakom; Seyfullah Yilmaz; Ines Dumsch; Sybille Allard; Ullrich Scherf; Michael Krüger

2011-01-01

463

Multicrystalline silicon solar cells: Gettering optimization and characterization  

NASA Astrophysics Data System (ADS)

Three multicrystalline silicon materials were used in preliminary experiments in preparation for a planned comprehensive gettering study on several industrial solar cell materials. Two processes commonly used to upgrade material quality were investigated: phosphorus gettering and aluminum-alloying. Microwave-detected photoconductance decay measurements of minority carrier lifetime and detailed analyses of full solar cells were used to determine the response to the gettering processes. Lateral nonuniformities were shown to be significant in these multicrystalline materials. Identification of the nature of the nonuniformities is important in developing an understanding of gettering effects.

Schubert, W. K.

464

Efficient broadband near-infrared quantum cutting for solar cells.  

PubMed

Yb(2+) and Yb(3+) co-activated luminescent material that can cut one photon in ultraviolet and visible region into multi NIR photons could be used as a downconversion luminescent convertor in front of crystalline silicon solar cell panels to reduce thermalization loss of the solar cell. After a direct excitation of Yb(2+) ions, an intense Yb(3+) luminescence is observed based on a cooperative energy transfer process. The energy transfer process is discussed according to the dependence of Yb(3+) luminescence intensity on the excitation power and the ambient temperature. PMID:20588816

Teng, Yu; Zhou, Jiajia; Liu, Xiaofeng; Ye, Song; Qiu, Jianrong

2010-04-26

465

Highly Mismatched Alloys for Intermediate Band Solar Cells  

SciTech Connect

It has long been recognized that the introduction of a narrow band of states in a semiconductor band gap could be used to achieve improved power conversion efficiency in semiconductor-based solar cells. The intermediate band would serve as a ''stepping stone'' for photons of different energy to excite electrons from the valence to the conduction band. An important advantage of this design is that it requires formation of only a single p-n junction, which is a crucial simplification in comparison to multijunction solar cells. A detailed balance analysis predicts a limiting efficiency of more than 50% for an optimized, single intermediate band solar cell. This is higher than the efficiency of an optimized two junction solar cell. Using ion beam implantation and pulsed laser melting we have synthesized Zn{sub 1-y}Mn{sub y}O{sub x}Te{sub 1-x} alloys with x<0.03. These highly mismatched alloys have a unique electronic structure with a narrow oxygen-derived intermediate band. The width and the location of the band is described by the Band Anticrossing model and can be varied by controlling the oxygen content. This provides a unique opportunity to optimize the absorption of solar photons for best solar cell performance. We have carried out systematic studies of the effects of the intermediate band on the optical and electrical properties of Zn{sub 1-y}Mn{sub y}O{sub x}Te{sub 1-x} alloys. We observe an extension of the photovoltaic response towards lower photon energies, which is a clear indication of optical transitions from the valence to the intermediate band.

Walukiewicz, W.; Yu, K.M.; Wu, J.; Ager III, J.W.; Shan, W.; Scrapulla, M.A.; Dubon, O.D.; Becla, P.

2005-03-21

466

Efficient planar heterojunction perovskite solar cells by vapour deposition.  

PubMed

Many different photovoltaic technologies are being developed for large-scale solar energy conversion. The wafer-based first-generation photovoltaic devices have been followed by thin-film solid semiconductor absorber layers sandwiched between two charge-selective contacts and nanostructured (or mesostructured) solar cells that rely on a distributed heterojunction to generate charge and to transport positive and negative charges in spatially separated phases. Although many materials have been used in nanostructured devices, the goal of attaining high-efficiency thin-film solar cells in such a way has yet to be achieved. Organometal halide perovskites have recently emerged as a promising material for high-efficiency nanostructured devices. Here we show that nanostructuring is not necessary to achieve high efficiencies with this material: a simple planar heterojunction solar cell incorporating vapour-deposited perovskite as the absorbing layer can have solar-to-electrical power conversion efficiencies of over 15 per cent (as measured under simulated full sunlight). This demonstrates that perovskite absorbers can function at the highest efficiencies in simplified device architectures, without the need for complex nanostructures. PMID:24025775

Liu, Mingzhen; Johnston, Michael B; Snaith, Henry J

2013-09-11

467

Metal-Metal Oxide Nanoomposite for Solar Cell Applications  

NASA Astrophysics Data System (ADS)

Currently, there is a large need for alternative energies and one good option is solar cells. A High efficiency solar cell generally consists of a number of thin layers: active layer consisting of a material having high absorption in the solar spectrum, transparent conducting layer, p- and n-type materials used to fabricate the junction, and electrodes for good Ohmic contacts. The presence of metal nanoparticles in metal oxide films improves significantly the solar absorbance of metal oxide films. The absorption depends on the bandgap of metal oxides which can be tuned by incorporation of metal nanoparticles. Tuning of the bandgap and absorption are the very important parameters to fabricate the solar cell devices. Thin films of M-MO (M = transition metals Co and Ni) nanocomposite have been grown on quartz substrate using pulse laser deposition technique. Structural properties have been characterized using X-ray diffraction and scanning electron microscopy. Electrical properties with and without light and absorption spectra have been measured using I-V characterization and UV-VIS spectroscopy techniques. Detailed results will be discussed in the presentation.

Gemar, H.; Ghosh, K.

2012-02-01

468

Development of Thin Solar Cells for Space Applications at NASA Glenn Research Center.  

National Technical Information Service (NTIS)

NASA GRC Thin Film Solar Cell program is developing solar cell technologies for space applications which address two critical metrics: higher specific power (power per unit mass) and lower launch stowed volume. To be considered for space applications, an ...

J. E. Dickman A. Hepp K. K. Banger J. D. Harris M. H. Jin

2003-01-01

469

Development of Low-Cost, High Energy-Per-Unit-Area Solar Cell Modules. Final Report.  

National Technical Information Service (NTIS)

The development of two hexagonal solar cell process sequences, a laser-scribing process technique for scribing hexagonal and modified hexagonal solar cells, a large throughput diffusion process, and two surface macrostructure processes suitable for large ...

G. T. Jones S. Chitre S. S. Rhee

1978-01-01

470

Award-Winning Etching Process Cuts Solar Cell Costs (Revised) (Fact Sheet)  

SciTech Connect

The NREL "black silicon" nanocatalytic wet-chemical etch is an inexpensive, one-step method to minimize reflections from crystalline silicon solar cells. The technology enables high-efficiency solar cells without the use of expensive antireflection coatings.

Not Available

2011-05-01

471

Influence of Wafer Thickness on the Performance of Multicrystalline SI Solar Cells: An Experimental Study.  

National Technical Information Service (NTIS)

The influence of the thickness of silicon solar cells has been investigated using neighboring multicrystalline silicon wafers with thickness ranging from 150 to 325 micrometers. For silicon solar cell structures with a high minority carrier diffusion leng...

C. J. J. Tool A. R. Burgers P. Manshanden A. W. Weeber B. H. M. van Straaten

2001-01-01

472

High-efficiency silicon solar cells by rapid thermal processing  

SciTech Connect

Silicon solar cell efficiencies of 16.9% have been achieved on 0.2 [Omega] cm float zone silicon, using a simplified cost effective rapid thermal process (RTP). Although the individual processing steps are not fully optimized yet, this represents the highest reported efficiency for solar cells processed with simultaneous front and back diffusion with no conventional high-temperature furnace steps. A diffusion temperature schedule coupled with an added short [ital in] [ital situ] slow cooling during RTP resulted in greater than 200 [mu]m diffusion length and appropriate diffusion profiles for high efficiency cells. Plasma enhanced chemical vapor deposition (PECVD) of SiN/SiO[sub 2] was used for surface passivation and antireflection coating. Conventional cells fabricated by furnace diffusions and oxidations gave an efficiency of 18.8%. Process optimization can further reduce the gap between the conventional and RTP/PECVD cells.

Rohatgi, A.; Chen, Z.; Doshi, P.; Pham, T. (University Center of Excellence for Photovoltaics Research and Education, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)); Ruby, D. (Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States))

1994-10-17

473

Carrier collectors for dye-sensitized solar cells  

NASA Astrophysics Data System (ADS)

Upscaling the dye sensitized solar cell (DSSC) is a key issue that confronting the entry of this type cells in commercial market. Performance of large size DSSCs is always poor than small size cells because of high resistive losses associated with sheet resistance of conducting glass substrates. Here we show a simple method to reduce resistive loss, also, efficient collection of photo generated carriers through silver current collectors which are prepared on both working electrode and counter electrode substrates by screen printing method in analogy to conventional silicon solar cells. For long-term stability, to protect corrosion and to avoid charge recombination, silver current collectors were laminated by surlyn sheet. Using these substrates, DSSCs were prepared and their I-V characteristics have been studied as a function of light intensity and compared with normal cells which don't have silver carrier collectors.

Lee, Won Jae; Ramasamy, Easwaramoorthi; Lee, Dong Yoon; Min, Bok Ki; Song, Jae Sung

2006-01-01

474

Increased photogeneration in thin silicon concentrator solar cells  

NASA Astrophysics Data System (ADS)

Recent progress in silicon concentrator solar cells has resulted in several designs capable of 25-percent efficiency with one group reporting 28 percent under 14 W/sq cm of incident power at 25 C. It has been shown that further improvement is possible by restricting the sunlight acceptance angle of the cell. In this letter, a practical implementation which is equivalent in its effect is proposed which results in an increased utilization of weakly absorbed near-bandgap light. This increased absorption is obtained by placing the cells in a cavity with a small entrance aperture. The design is expected to improve the efficiencies of existing solar cells to 30 percent. If used in conjuction with previously proposed cell improvements, the efficiencies will be improved towards 33 percent, very near the limit efficiency of 36 percent.

Sinton, Ronald A.; Swanson, Richard M.

1987-11-01