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Sample records for zinc phosphide solar cells

  1. Photovoltaic cells employing zinc phosphide

    DOEpatents

    Barnett, Allen M. (Newark, DE); Catalano, Anthony W. (Wilmington, DE); Dalal, Vikram L. (Newark, DE); Masi, James V. (Wilbraham, MA); Meakin, John D. (Newark, DE); Hall, Robert B. (Newark, DE)

    1984-01-01

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

  2. Zinc phosphide

    Integrated Risk Information System (IRIS)

    Zinc phoshide ; CASRN 1314 - 84 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef

  3. Determination of series resistance of indium phosphide solar cells

    NASA Technical Reports Server (NTRS)

    Jain, Raj K.; Weinberg, Irving

    1991-01-01

    The series resistance of a solar cell is an important parameter, which must be minimized to achieve high cell efficiencies. The cell series resistance is affected by the starting material, its design, and processing. The theoretical approach proposed by Jia, et. al., is used to calculate the series resistance of indium phosphide solar cells. It is observed that the theoretical approach does not predict the series resistance correctly in all cases. The analysis was modified to include the use of effective junction ideality factor. The calculated results were compared with the available experimental results on indium phosphide solar cells processed by different techniques. It is found that the use of process dependent junction ideality factor leads to better estimation of series resistance. An accurate comprehensive series resistance model is warranted to give proper feedback for modifying the cell processing from the design state.

  4. Indium phosphide solar cells for laser power beaming applications

    NASA Technical Reports Server (NTRS)

    Jain, Raj K.; Landis, Geoffrey A.

    1992-01-01

    Lasers can be used to transmit power to photovoltaic cells. Solar cell efficiencies are enhanced significantly under monochromatic light, and therefore a laser beam of proper wavelength could be a very effective source of illumination for a solar array operating at very high efficiencies. This work reviews the modeling studies made on indium phosphide solar cells for such an application. These cells are known to be very radiation resistant and have a potential for high efficiency. Effects of cell series resistance, laser intensity, and temperature on cell performance have been discussed.

  5. Zinc Phosphide Poisoning

    PubMed Central

    Do?an, Erdal; Güzel, Abdulmenap; Çiftçi, Taner; Aycan, ?lker; Çetin, Bedri; Kavak, Gönül Ölmez

    2014-01-01

    Zinc phosphide has been used widely as a rodenticide. Upon ingestion, it gets converted to phosphine gas in the body, which is subsequently absorbed into the bloodstream through the stomach and the intestines and gets captured by the liver and the lungs. Phosphine gas produces various metabolic and nonmetabolic toxic effects. Clinical symptoms are circulatory collapse, hypotension, shock symptoms, myocarditis, pericarditis, acute pulmonary edema, and congestive heart failure. In this case presentation, we aim to present the intensive care process and treatment resistance of a patient who ingested zinc phosphide for suicide purposes. PMID:25101186

  6. Indium phosphide space solar cell research: Where we are and where we are going

    NASA Technical Reports Server (NTRS)

    Jain, R. K.; Flood, D. J.; Weinberg, Irving

    1995-01-01

    Indium phosphide is considered to be a strong contender for many photovoltaic space applications because of its radiation resistance and its potential for high efficiency. An overview of recent progress is presented, and possible future research directions for indium phosphide space solar cells are discussed. The topics considered include radiation damage studies and space flight experiments.

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

    NASA Technical Reports Server (NTRS)

    Jain, Raj K.

    2005-01-01

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

  8. Optimal design study of high efficiency indium phosphide space solar cells

    NASA Technical Reports Server (NTRS)

    Jain, Raj K.; Flood, Dennis J.

    1990-01-01

    Recently indium phosphide solar cells have achieved beginning of life AMO efficiencies in excess of 19 pct. at 25 C. The high efficiency prospects along with superb radiation tolerance make indium phosphide a leading material for space power requirements. To achieve cost effectiveness, practical cell efficiencies have to be raised to near theoretical limits and thin film indium phosphide cells need to be developed. The optimal design study is described of high efficiency indium phosphide solar cells for space power applications using the PC-1D computer program. It is shown that cells with efficiencies over 22 pct. AMO at 25 C could be fabricated by achieving proper material and process parameters. It is observed that further improvements in cell material and process parameters could lead to experimental cell efficiencies near theoretical limits. The effect of various emitter and base parameters on cell performance was studied.

  9. 40 CFR 180.284 - Zinc phosphide; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Zinc phosphide; tolerances for residues. 180.284 Section 180.284...EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances ...Zinc phosphide; tolerances for residues. (a) General....

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

    NASA Technical Reports Server (NTRS)

    Jain, Raj K.; Landis, Geoffrey A.

    1992-01-01

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

  11. Effect of emitter parameter variation on the performance of heteroepitaxial indium phosphide solar cells

    NASA Technical Reports Server (NTRS)

    Jain, Raj K.; Flood, Dennis J.

    1990-01-01

    Metallorganic chemical-vapor-deposited heteroepitaxial indium phosphide (InP) solar cell experimental results were simulated by using a PC-1D computer model. The effect of emitter parameter variation on the performance of n(+)/p/p(+) heteroepitaxial InP/GaAs solar cell was presented. The thinner and lighter doped emitters were observed to offer higher cell efficiencies. The influence of emitter thickness and minority carrier diffusion length on the cell efficiency with respect to dislocation density was studied. Heteroepitaxial cells with efficiencies similar to present day homojunction InP efficiencies (greater than 16 percent AMO) were shown to be attainable if a dislocation density lower than 10(exp 6)/sq cm could be achieved. A realistic optimized design study yielded InP solar cells of over 22 percent AMO efficiency at 25 C.

  12. 40 CFR 180.284 - Zinc phosphide; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Zinc phosphide; tolerances for... § 180.284 Zinc phosphide; tolerances for residues. (a) General. Tolerances are established for residues of the phosphine resulting from the use of the rodenticide zinc phosphide in or on the...

  13. 40 CFR 180.284 - Zinc phosphide; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Zinc phosphide; tolerances for... § 180.284 Zinc phosphide; tolerances for residues. (a) General. Tolerances are established for residues of the phosphine resulting from the use of the rodenticide zinc phosphide in or on the...

  14. 40 CFR 180.284 - Zinc phosphide; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Zinc phosphide; tolerances for... § 180.284 Zinc phosphide; tolerances for residues. (a) General. Tolerances are established for residues of the phosphine resulting from the use of the rodenticide zinc phosphide in or on the...

  15. 40 CFR 180.284 - Zinc phosphide; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Zinc phosphide; tolerances for... § 180.284 Zinc phosphide; tolerances for residues. (a) General. Tolerances are established for residues of the phosphine resulting from the use of the rodenticide zinc phosphide in or on the...

  16. 40 CFR 180.284 - Zinc phosphide; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Zinc phosphide; tolerances for... § 180.284 Zinc phosphide; tolerances for residues. (a) General. Tolerances are established for residues of the phosphine resulting from the use of the rodenticide zinc phosphide in or on the...

  17. Forward-biased current annealing of radiation degraded indium phosphide and gallium arsenide solar cells

    NASA Technical Reports Server (NTRS)

    Michael, Sherif; Cypranowski, Corinne; Anspaugh, Bruce

    1990-01-01

    The preliminary results of a novel approach to low-temperature annealing of previously irradiated indium phosphide and gallium arsenide solar cells are reported. The technique is based on forward-biased current annealing. The two types of III-V solar cells were irradiated with 1-MeV electrons to a fluence level of (1-10) x 10 to the 14th electrons/sq cm. Several annealing attempts were made, varying all conditions. Optimum annealing was achieved when cells were injected with minority currents at a constant 90 C. The current density for each type of cell was also determined. Significant recovery of degraded parameters was achieved in both cases. However, the InP cell recovery notably exceeded the recovery in GaAs cells. The recovery is thought to be caused by current-stimulated reordering of the radiator-induced displacement damage. Both types of cell were then subjected to several cycles of irradiation and annealing. The results were also very promising. The significant recovery of degraded cell parameters at low temperature might play a major role in considerably extending the end of life of future spacecraft.

  18. Diffusion length variation in 0.5- and 3-MeV-proton-irradiated, heteroepitaxial indium phosphide solar cells

    NASA Technical Reports Server (NTRS)

    Jain, Raj K.; Weinberg, Irving; Flood, Dennis J.

    1993-01-01

    Indium phosphide (InP) solar cells are more radiation resistant than gallium arsenide (GaAs) and silicon (Si) solar cells, and their growth by heteroepitaxy offers additional advantages leading to the development of light weight, mechanically strong, and cost-effective cells. Changes in heteroepitaxial InP cell efficiency under 0.5- and 3-MeV proton irradiations have been explained by the variation in the minority-carrier diffusion length. The base diffusion length versus proton fluence was calculated by simulating the cell performance. The diffusion length damage coefficient, K(sub L), was also plotted as a function of proton fluence.

  19. Diphacinone and zinc phosphide toxicity in a flock of Peafowl.

    PubMed

    Shivaprasad, H L; Galey, F

    2001-12-01

    Toxicity probably due to a combination of diphacinone and zinc phosphide was diagnosed in a flock of peafowl, in which 35 birds in a flock of 80 died over a span of 10 days without any apparent clinical signs. Chickens and guinea fowl, 30 each on the same premises, were not affected. Plastic tubes containing diphacinone and zinc phosphide were used on the premises to control ground squirrels. Most of the six dead peafowl, which ranged in age from 6 months to 4 years, had an accumulation of serosanguinous fluid in the abdominal cavity, semi-clotted blood over the liver lobes, increased pericardial fluid, and enlarged and pale kidneys. Pellets of diphacinone and zinc phosphide were found in the crop and gizzard contents from most of the birds. Microscopically, most of the birds had mild to moderate centrolobular degeneration of hepatocytes and multifocal degeneration of myofibres in the heart with infiltration by a few mononuclear cells. Acute nephrosis and mucosal oedema in the oesophagus and crop were also observed. Toxicological analysis of the crop and gizzard contents revealed the presence of diphacinone and phosphine gas, and analysis of the crop contents from two birds for heavy metals revealed zinc levels of up to 6600 parts/10 6 . It was suspected that only the peafowl and not the chickens and guinea fowl were affected because peafowl, with their longer necks, were able to reach into the plastic tubes and eat the pellets. PMID:19184953

  20. A numerical simulation study of gallium-phosphide/silicon heterojunction passivated emitter and rear solar cells

    SciTech Connect

    Wagner, Hannes; Ohrdes, Tobias; Dastgheib-Shirazi, Amir; Puthen-Veettil, Binesh; König, Dirk; Altermatt, Pietro P.

    2014-01-28

    The performance of passivated emitter and rear (PERC) solar cells made of p-type Si wafers is often limited by recombination in the phosphorus-doped emitter. To overcome this limitation, a realistic PERC solar cell is simulated, whereby the conventional phosphorus-doped emitter is replaced by a thin, crystalline gallium phosphide (GaP) layer. The resulting GaP/Si PERC cell is compared to Si PERC cells, which have (i) a standard POCl{sub 3} diffused emitter, (ii) a solid-state diffused emitter, or (iii) a high efficiency ion-implanted emitter. The maximum efficiencies for these realistic PERC cells are between 20.5% and 21.2% for the phosphorus-doped emitters (i)–(iii), and up to 21.6% for the GaP emitter. The major advantage of this GaP hetero-emitter is a significantly reduced recombination loss, resulting in a higher V{sub oc}. This is so because the high valence band offset between GaP and Si acts as a nearly ideal minority carrier blocker. This effect is comparable to amorphous Si. However, the GaP layer can be contacted with metal fingers like crystalline Si, so no conductive oxide is necessary. Compared to the conventional PERC structure, the GaP/Si PERC cell requires a lower Si base doping density, which reduces the impact of the boron-oxygen complexes. Despite the lower base doping, fewer rear local contacts are necessary. This is so because the GaP emitter shows reduced recombination, leading to a higher minority electron density in the base and, in turn, to a higher base conductivity.

  1. Solution-based synthesis and purification of zinc tin phosphide nanowires

    NASA Astrophysics Data System (ADS)

    Sheets, Erik J.; Balow, Robert B.; Yang, Wei-Chang; Stach, Eric A.; Agrawal, Rakesh

    2015-11-01

    The solution-based synthesis of nanoscale earth-abundant semiconductors has the potential to unlock simple, scalable, and tunable material processes which currently constrain development of novel compounds for alternative energy devices. One such promising semiconductor is zinc tin phosphide (ZnSnP2). We report the synthesis of ZnSnP2 nanowires via a solution-liquid-solid mechanism utilizing metallic zinc and tin in decomposing trioctylphosphine (TOP). Dried films of the reaction product are purified of binary phosphide phases by annealing at 345 °C. Tin is removed using a 0.1 M nitric acid treatment leaving pure ZnSnP2 nanowires. Diffuse reflectance spectroscopy indicates ZnSnP2 has a direct bandgap energy of 1.24 eV which is optimal for solar cell applications. Using a photoelectrochemical cell, we demonstrate cathodic photocurrent generation at open circuit conditions from the ZnSnP2 nanowires upon solar simulated illumination confirming p-type conductivity.The solution-based synthesis of nanoscale earth-abundant semiconductors has the potential to unlock simple, scalable, and tunable material processes which currently constrain development of novel compounds for alternative energy devices. One such promising semiconductor is zinc tin phosphide (ZnSnP2). We report the synthesis of ZnSnP2 nanowires via a solution-liquid-solid mechanism utilizing metallic zinc and tin in decomposing trioctylphosphine (TOP). Dried films of the reaction product are purified of binary phosphide phases by annealing at 345 °C. Tin is removed using a 0.1 M nitric acid treatment leaving pure ZnSnP2 nanowires. Diffuse reflectance spectroscopy indicates ZnSnP2 has a direct bandgap energy of 1.24 eV which is optimal for solar cell applications. Using a photoelectrochemical cell, we demonstrate cathodic photocurrent generation at open circuit conditions from the ZnSnP2 nanowires upon solar simulated illumination confirming p-type conductivity. Electronic supplementary information (ESI) available: Characterization details, synthesis of Zn3P2 and Sn4P3, GC-MS, ZnSnP2 optimization experiments, diffuse reflectance calculations, Rietveld refinement, ZnSnP2 SAED, TEM EDS data, and TGA data. See DOI: 10.1039/c5nr05171a

  2. 40 CFR 180.284 - Zinc phosphide; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...rodenticide zinc phosphide in or on the following raw agricultural commodities as follows: Commodity Parts per million Artichoke, globe 0.01 Beet, sugar, roots 0.04 Beet, sugar, tops 0.02 (d) Indirect or inadvertent...

  3. 40 CFR 180.284 - Zinc phosphide; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...rodenticide zinc phosphide in or on the following raw agricultural commodities as follows: Commodity Parts per million Artichoke, globe 0.01 Beet, sugar, roots 0.04 Beet, sugar, tops 0.02 (d) Indirect or inadvertent...

  4. 40 CFR 180.284 - Zinc phosphide; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...rodenticide zinc phosphide in or on the following raw agricultural commodities as follows: Commodity Parts per million Artichoke, globe 0.01 Beet, sugar, roots 0.04 Beet, sugar, tops 0.02 (d) Indirect or inadvertent...

  5. 40 CFR 180.284 - Zinc phosphide; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...rodenticide zinc phosphide in or on the following raw agricultural commodities as follows: Commodity Parts per million Artichoke, globe 0.01 Beet, sugar, roots 0.04 Beet, sugar, tops 0.02 (d) Indirect or inadvertent...

  6. Simulation of high-efficiency n[sup +]p indium phosphide solar cell results and future improvements

    SciTech Connect

    Jain, R.K.; Flood, D.J. )

    1994-12-01

    A simulation of the highest efficiency (19.1% AM0) n[sup +]p indium phosphide (InP) solar cell was made using a computer code PC-1D in order to understand it and suggest future improvements to it. Available cell design and process data was used in the simulation. Minority carrier diffusion lengths in the emitter and base have been varied to match the experimental cell I-V characteristics with the calculated results. To further understand and improve the InP cell efficiency, simulations were performed using improved values of cell material and process parameters. The authors show that the efficiency of this cell could be increased to more than 23% AM0 by incorporating the suggested cell material, design and process improvements. At these high efficiencies InP cell technology will be very attractive for space use.

  7. Effect of dislocations on the open-circuit voltage, short-circuit current and efficiency of heteroepitaxial indium phosphide solar cells

    NASA Technical Reports Server (NTRS)

    Jain, Raj K.; Flood, Dennis J.

    1990-01-01

    Excellent radiation resistance of indium phosphide solar cells makes them a promising candidate for space power applications, but the present high cost of starting substrates may inhibit their large scale use. Thin film indium phosphide cells grown on Si or GaAs substrates have exhibited low efficiencies, because of the generation and propagation of large number of dislocations. Dislocation densities were calculated and its influence on the open circuit voltage, short circuit current, and efficiency of heteroepitaxial indium phosphide cells was studied using the PC-1D. Dislocations act as predominant recombination centers and are required to be controlled by proper transition layers and improved growth techniques. It is shown that heteroepitaxial grown cells could achieve efficiencies in excess of 18 percent AMO by controlling the number of dislocations. The effect of emitter thickness and surface recombination velocity on the cell performance parameters vs. dislocation density is also studied.

  8. Solution-based synthesis and purification of zinc tin phosphide nanowires.

    PubMed

    Sheets, Erik J; Balow, Robert B; Yang, Wei-Chang; Stach, Eric A; Agrawal, Rakesh

    2015-12-01

    The solution-based synthesis of nanoscale earth-abundant semiconductors has the potential to unlock simple, scalable, and tunable material processes which currently constrain development of novel compounds for alternative energy devices. One such promising semiconductor is zinc tin phosphide (ZnSnP2). We report the synthesis of ZnSnP2 nanowires via a solution-liquid-solid mechanism utilizing metallic zinc and tin in decomposing trioctylphosphine (TOP). Dried films of the reaction product are purified of binary phosphide phases by annealing at 345 °C. Tin is removed using a 0.1 M nitric acid treatment leaving pure ZnSnP2 nanowires. Diffuse reflectance spectroscopy indicates ZnSnP2 has a direct bandgap energy of 1.24 eV which is optimal for solar cell applications. Using a photoelectrochemical cell, we demonstrate cathodic photocurrent generation at open circuit conditions from the ZnSnP2 nanowires upon solar simulated illumination confirming p-type conductivity. PMID:26530669

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

    E-print Network

    Tu, Bor-An Clayton

    2013-01-01

    tandem solar cell with 10.6% power conversion efficiency. ,”picture of the power conversion efficiency of solar cells,solar cell under light. Source: National Instruments [57] The final power conversion efficiency (

  10. Lattice-mismatched In(0.40)Al(0.60)As window layers for indium phosphide solar cells

    NASA Technical Reports Server (NTRS)

    Jain, Raj K.; Landis, Geoffrey A.; Wilt, David M.; Flood, Dennis J.

    1993-01-01

    The efficiency of indium phosphide (InP) solar cells is limited by its high surface recombination velocity (approximately 10(exp 7) cm/s). This might be reduced by a wide-bandgap window layer. The performance of InP solar cells with wide-bandgap (1.8 eV) lattice-mismatched In(0.40)Al(0.60)As as a window layer was calculated. Because the required window layer thickness is less than the critical layer thickness, growth of strained (pseudomorphic) layers without interfacial misfit dislocations should be possible. Calculations using the PC-lD numerical code showed that the efficiencies of baseline and optimized p(+)n (p-on-n) cells are increased to more than 22 and 24 percent, (air mass zero (AMO), 25 C), respectively for a lattice-mismatched In(0.40)Al(0.60)As window layer of 10-nm thickness. Currently, most cell development work has been focused on n(+)p (n-on-p) structures although comparatively little improvement has been found for n(+)p cells.

  11. Responses of Siberian ferrets to secondary zinc phosphide poisoning

    USGS Publications Warehouse

    Hill, E.F.; Carpenter, J.W.

    1982-01-01

    The hazard of operational-type applications of zinc phosphide (Zn3P2) on a species closely related to the black-footed ferret (Mustela nigripes), was evaluated by feeding 16 Siberian ferrets (M. eversmanni) rats that had been killed by consumption of 2% zinc phosphide treated bait or by an oral dose of 40, 80, or 160 mg of Zn3P2. All ferrets accepted rats and a single emesis by each of 3 ferrets was the only evidence of acute intoxication. All ferrets learned to avoid eating gastrointestinal tracts of the rats. Subacute zinc phosphide toxicity in the ferrets was indicated by significant decreases (18-48%) in hemoglobin, increases of 35-91 % in serum iron, and elevated levels of serum globulin, cholesterol, and triglycerides. Hemoglobin/iron, urea nitrogen/creatinine, and albumin/globulin ratios also were altered by the treatments. This study demonstrated that Siberian ferrets, or other species with a sensitive emetic reflex, are afforded a degree of protection from acute zinc phosphide poisoning due to its emetic action. The importance of toxicity associated with possible respiratory, liver, and kidney damage indicated by altered blood chemistries is not known.

  12. Influence of the Dislocation Density on the Performance of Heteroepitaxial Indium Phosphide Solar Cells

    NASA Technical Reports Server (NTRS)

    Jain, R. K.; Flood, D. J.

    1991-01-01

    Calculations are made to study the dependence of heteroepitaxial InP solar-cell efficiency on dislocation density. Effects of surface recombination velocity and cell emitter thickness are considered. Calculated results are compared with the available experimental results on representative InP solar cells. It is shown that heteroepitaxial InP cells with over 20 percent AM0 efficiency could be fabricated if dislocations are reduced to less than 100,000/sq cm.

  13. Theoretical modeling, near-optimum design and predicted performance of n(+)pp(+) and p(+)nn(+) indium phosphide homojunction solar cells

    NASA Technical Reports Server (NTRS)

    Goradia, Chandra; Thesling, William; Weinberg, Irving

    1991-01-01

    Using a detailed simulation model of p(+)nn(+) and n(+)pp(+) indium phosphide (InP) homojunction solar cells, extensive parametric variation computer simulation runs are conducted to help arrive at near-optimum designs of these two solar cell configurations. Values of all the geometrical and material parameters corresponding to the near-optimal designs of both these configurations are presented. For each configuration, results are given for parametric variation runs showing how the performance parameters JSC, VOC, and eta vary with each of the cell parameters for the near-optimally designed cell.

  14. Three-dimensional numerical modeling of indium phosphide Point-Contact Solar Cells

    NASA Technical Reports Server (NTRS)

    Clark, Ralph O.

    1992-01-01

    The Point-Contact Solar Cell (PCSC) geometry has proven very effective for silicon cells. To date, it has not been implemented in III-V materials. In addition, modeling such a geometry is very difficult because of its three-dimensional nature. We have developed a three-dimensional finite element modeling code (FIESTA ROC). In this paper, we present results from a three-dimensional modeling study of InP point-contact solar cells.

  15. Indium phosphide solar cell research in the US: Comparison with nonphotovoltaic sources

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

    Highlights of the InP solar cell research program are presented. Homojunction cells with AMO efficiences approaching 19 percent were demonstrated while 17 percent was achieved for indium tin oxide (ITO)/InP cells. The superior radiation resistance of these latter two cell configurations over both Si and GaAs were demonstrated. InP cells on board the LIPS III satellite show no degradation after more than a year in orbit. Computer modeling calculations were directed toward radiation damage predictions and the specification of concentrator cell parameters. Computed array specific powers, for a specific orbit, are used to compare the performance of an InP solar cell array to solar dynamic and nuclear systems.

  16. Effect of zinc impurity on silicon solar-cell efficiency

    NASA Technical Reports Server (NTRS)

    Sah, C.-T.; Chan, P. C. H.; Wang, C.-K.; Yamakawa, K. A.; Lutwack, R.; Sah, R. L.-Y.

    1981-01-01

    Zinc is a major residue impurity in the preparation of solar-grade silicon material by the zinc vapor reduction of silicon tetrachloride. This paper projects that in order to get a 17-percent AM1 cell efficiency for the Block IV module of the Low-Cost Solar Array Project, the concentration of the zinc recombination centers in the base region of silicon solar cells must be less than 4 x 10 to the 11th Zn/cu cm in the p-base n+/p/p+ cell and 7 x 10 to the 11th Zn/cu cm in the n-base p+/n/n+ cell for a base dopant impurity concentration of 5 x 10 to the 14 atoms/cu cm. If the base dopant impurity concentration is increased by a factor of 10 to 5 x 10 to the 15th atoms/cu cm, then the maximum allowable zinc concentration is increased by a factor of about two for a 17-percent AM1 efficiency. The thermal equilibrium electron and hole recombination and generation rates at the double-acceptor zinc centers are obtained from previous high-field measurements as well as new measurements at zero field described in this paper. These rates are used in the exact dc-circuit model to compute the projections.

  17. Naval Research Laboratory's programs in advanced indium phosphide solar cell development

    NASA Technical Reports Server (NTRS)

    Summers, Geoffrey P.

    1996-01-01

    The Naval Research Laboratory (NRL) has been involved in the development of solar cells for space applications since the 1960s. It quickly became apparent in this work that radiation damage caused to solar cells by electrons and protons trapped by the earth's magnetic field would seriously degrade the power output of photovoltaic arrays in extended missions. Techniques were therefore developed to harden the cells by shielding them with coverglass, etc. Ultimately, however, there is a limit to such approaches, which is determined by the radiation response of the semiconductor material employed. A desire for high efficiency and radiation resistance led to the development of alternative cell technologies such as GaAs, which has since become the technology of choice for many applications. InP cells are currently the most radiation resistant, high efficiency, planar cells known. NRL first sponsored InP solar cell technology in 1986, when Arizona State University was contracted to grow p/n cells by liquid phase epitaxy. NRL's interest in InP cells was generated by the results presented by Yamaguchi and his co-workers in the early 1980s on the remarkable radiation resistance of cells grown by diffusion of S into Zn doped p-type InP substrates. These cells also had beginning of life (BOL) efficiencies approximately 16%(AM0). Related to the radiation resistance of the cells was the fact that radiation-induced damage could be optically annealed by sunlight. Relatively large quantities of 1 x 2 cm(exp 2) diffused junction cells were made and were used on the MUSES-A and the EXOS-D satellites. These cells were also available in the U.S. through NIMCO, and were studied at NRL and elsewhere. Workers at NASA Lewis became involved in research in InP cells about the same time as NRL.

  18. Indium tin oxide and indium phosphide heterojunction nanowire array solar cells

    SciTech Connect

    Yoshimura, Masatoshi Nakai, Eiji; Fukui, Takashi; Tomioka, Katsuhiro; PRESTO, Japan Science and Technology Agency , Honcho Kawaguchi, 332–0012 Saitama

    2013-12-09

    Heterojunction solar cells were formed with a position-controlled InP nanowire array sputtered with indium tin oxide (ITO). The ITO not only acted as a transparent electrode but also as forming a photovoltaic junction. The devices exhibited an open-circuit voltage of 0.436?V, short-circuit current of 24.8?mA/cm{sup 2}, and fill factor of 0.682, giving a power conversion efficiency of 7.37% under AM1.5?G illumination. The internal quantum efficiency of the device was higher than that of the world-record InP cell in the short wavelength range.

  19. Naval Research Laboratory`s programs in advanced indium phosphide solar cell development

    SciTech Connect

    Summers, G.P.

    1995-10-01

    The Naval Research Laboratory has been involved in developing InP solar cell technology since 1988. The purpose of these programs was to produce advanced cells for use in very high radiation environments, either as a result of operating satellites in the Van Allen belts or for very long duration missions in other orbits. Richard Statler was technical representative on the first program, with Spire Corporation as the contractor, which eventually produced several hundred, high efficiency 2 x 2 sq cm single crystal InP cells. The shallow homojunction technology which was developed in this program enabled cells to be made with AMO, one sun efficiencies greater than 19%. Many of these cells have been flown on space experiments, including PASP Plus, which have confirmed the high radiation resistance of InP cells. NRL has also published widely on the radiation response of these cells and also on radiation-induced defect levels detected by DLTS, especially the work of Rob Walters and Scott Messenger. In 1990 NRL began another Navy-sponsored program with Tim Coutts and Mark Wanlass at the National Renewable Energy Laboratory (NREL), to develop a one sun, two terminal space version of the InP-InGaAs tandem junction cell being investigated at NREL for terrestrial applications. These cells were grown on InP substrates. Several cells with AMO, one sun efficiencies greater than 22% were produced. Two 2 x 2 sq cm cells were incorporated on the STRV lA/B solar cell experiment. These were the only two junction, tandem cells on the STRV experiment. The high cost and relative brittleness of InP wafers meant that if InP cell technology were to become a viable space power source, the superior radiation resistance of InP would have to be combined with a cheaper and more robust substrate. The main technical challenge was to overcome the effect of the dislocations produced by the lattice mismatch at the interface of the two materials.

  20. Naval Research Laboratory's programs in advanced indium phosphide solar cell development

    NASA Technical Reports Server (NTRS)

    Summers, Geoffrey P.

    1995-01-01

    The Naval Research Laboratory has been involved in developing InP solar cell technology since 1988. The purpose of these programs was to produce advanced cells for use in very high radiation environments, either as a result of operating satellites in the Van Allen belts or for very long duration missions in other orbits. Richard Statler was technical representative on the first program, with Spire Corporation as the contractor, which eventually produced several hundred, high efficiency 2 x 2 sq cm single crystal InP cells. The shallow homojunction technology which was developed in this program enabled cells to be made with AMO, one sun efficiencies greater than 19%. Many of these cells have been flown on space experiments, including PASP Plus, which have confirmed the high radiation resistance of InP cells. NRL has also published widely on the radiation response of these cells and also on radiation-induced defect levels detected by DLTS, especially the work of Rob Walters and Scott Messenger. In 1990 NRL began another Navy-sponsored program with Tim Coutts and Mark Wanlass at the National Renewable Energy Laboratory (NREL), to develop a one sun, two terminal space version of the InP-InGaAs tandem junction cell being investigated at NREL for terrestrial applications. These cells were grown on InP substrates. Several cells with AM0, one sun efficiencies greater than 22% were produced. Two 2 x 2 sq cm cells were incorporated on the STRV lA/B solar cell experiment. These were the only two junction, tandem cells on the STRV experiment. The high cost and relative brittleness of InP wafers meant that if InP cell technology were to become a viable space power source, the superior radiation resistance of InP would have to be combined with a cheaper and more robust substrate. The main technical challenge was to overcome the effect of the dislocations produced by the lattice mismatch at the interface of the two materials. Over the last few years, NRL and Steve Wojtczuk at Spire have been developing a single junction InP on Si cell, in an ONR-sponsored SBIR program. Both cell polarities were investigated and the best efficiencies to date (approximately 13% on a 2 x 4 sq cm cell) were achieved with n/p cells. Earlier this year NRL began a program with ASEC to develop a two terminal InP-InGaAs tandem cell on a Ge substrate. RTI and NREL are subcontractors on this program. The results of an ONR-sponsored study of the potential market for InP/Si cells will be discussed. Also the technical status of both the InP/Si and the InP-InGaAs/Ge programs will be given. The technical challenges still remaining will be briefly described.

  1. A theoretical comparison of the near-optimum design and predicted performance of n/p and p/n indium phosphide homojunction solar cells

    NASA Technical Reports Server (NTRS)

    Goradia, Chandra; Thesling, William; Weinberg, Irving

    1991-01-01

    Using a detailed simulation model of p(+)nn(+) and n(+)pp(+) indium phosphide (InP) homojunction solar cells, extensive parametric variation computer simulation runs were performed to aid in making near-optimum designs for these two solar cell configurations. The values of all the geometrical and material parameters corresponding to the near-optimal designs of both these configurations are presented. The results of parametric variation runs are presented for each configuration showing how the performance parameters J(sub sc), V(sub oc), and eta vary with each of the cell design parameters for the near-optimally designed cell. Finally, the theoretically obtained results are discussed, and the relative merits and drawbacks of the two configurations are compared.

  2. 1-Dimensional Zinc Oxide Nanomaterial Growth and Solar Cell Applications

    NASA Astrophysics Data System (ADS)

    Choi, Hyung Woo

    Zinc oxide (ZnO) has attracted much interest during last decades as a functional material. Furthermore, ZnO is a potential material for transparent conducting oxide material competing with indium tin oxide (ITO), graphene, and carbon nanotube film. It has been known as a conductive material when doped with elements such as indium, gallium and aluminum. The solubility of those dopant elements in ZnO is still debatable; but, it is necessary to find alternative conducting materials when their form is film or nanostructure for display devices. This is a consequence of the ever increasing price of indium. In addition, a new generation solar cell (nanostructured or hybrid photovoltaics) requires compatible materials which are capable of free standing on substrates without seed or buffer layers and have the ability introduce electrons or holes pathway without blocking towards electrodes. The nanostructures for solar cells using inorganic materials such as silicon (Si), titanium oxide (TiO2), and ZnO have been an interesting topic for research in solar cell community in order to overcome the limitation of efficiency for organic solar cells. This dissertation is a study of the rational solution-based synthesis of 1-dimentional ZnO nanomaterial and its solar cell applications. These results have implications in cost effective and uniform nanomanufacturing for the next generation solar cells application by controlling growth condition and by doping transition metal element in solution.

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

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

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

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

    SciTech Connect

    Chu, T.L. )

    1992-04-01

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

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

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A. (Inventor)

    2006-01-01

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

  7. Low-Resistivity Zinc Selenide for Heterojunctions

    NASA Technical Reports Server (NTRS)

    Stirn, R. J.

    1986-01-01

    Magnetron reactive sputtering enables doping of this semiconductor. Proposed method of reactive sputtering combined with doping shows potential for yielding low-resistivity zinc selenide films. Zinc selenide attractive material for forming heterojunctions with other semiconductor compounds as zinc phosphide, cadmium telluride, and gallium arsenide. Semiconductor junctions promising for future optoelectronic devices, including solar cells and electroluminescent displays. Resistivities of zinc selenide layers deposited by evaporation or chemical vapor deposition too high to form practical heterojunctions.

  8. A very low resistance, non-sintered contact system for use on indium phosphide concentrator/shallow junction solar cells

    NASA Technical Reports Server (NTRS)

    Weizer, Victor G.; Fatemi, Navid S.

    1991-01-01

    An investigation is made into the possibility of providing low resistance contacts to shallow junction InP solar cells which do not require sintering and which do not cause device degradation even when subjected to extended annealing at elevated temperatures. We show that the addition of In to Au contacts in amounts that exceed the solid solubility limit lowers the as-fabricated (unsintered) contact resistivity (R sub c) to the 10(exp -5) ohm cm(exp 2) range. We next consider the contact system Au/Au2P3, which has been shown to exhibit as-fabricated R sub c values in the 10(exp -6) ohm cm(exp 2) range, but which fails quickly when heated. We show that the substitution of a refractory metal (W, Ta) for Au preserves the low R sub c values while preventing the destructive reactions that would normally take place in this system at high temperatures. We show, finally, that R sub c values in the 10(exp -7) ohm cm(exp 2) range can be achieved without sintering by combining the effects of In or Ga additions to Au contacts with the effects of introducing a thin Au2P3 layer at the metal-InP interface.

  9. Synthesis of zinc chlorophyll materials for dye-sensitized solar cell applications

    NASA Astrophysics Data System (ADS)

    Erten-Ela, Sule; Vakuliuk, Olena; Tarnowska, Anna; Ocakoglu, Kasim; Gryko, Daniel T.

    2015-01-01

    To design sensitizers for dye sensitized solar cells (DSSCs), a series of zinc chlorins with different substituents were synthesized. Novel zinc methyl 3-devinyl-3-hydroxymethyl-20-phenylacetylenylpyropheophorbide-a (ZnChl-1), zinc methyl 20-bromo-3-devinyl-3-hydroxymethylpyropheophorbide-a (ZnChl-2), zinc methyl 3-devinyl-3-hydroxymethyl-pyropheophorbide-a (ZnChl-3), zinc propyl 3-devinyl-3-hydroxymethyl-pyropheophorbide-a (ZnChl-4) were synthesized and their photovoltaic performances were evaluated in dye-sensitized solar cells. Photoelectrodes with a 7 ?m thick nanoporous layer and a 5 ?m thick light-scattering layer were used to fabricate dye sensitized solar cells. The best efficiency was obtained with ZnChl-2 sensitizer. ZnChl-2 gave a Jsc of 3.5 mA/cm2, Voc of 412 mV, FF of 0.56 and an overall conversion efficiency of 0.81 at full sun (1000 W m-2).

  10. Efficient inverted polymer solar cells based on conjugated polyelectrolyte and zinc oxide modified ITO electrode

    SciTech Connect

    Yuan, Tao; Zhu, Xiaoguang; Tu, Guoli; Zhou, Lingyu; Zhang, Jian

    2015-02-23

    Efficient inverted polymer solar cells (PSCs) were constructed by utilizing a conjugated polyelectrolyte PF{sub EO}SO{sub 3}Na and zinc oxide to modify the indium tin oxide (ITO) electrode. The ITO electrode modified by PF{sub EO}SO{sub 3}Na and zinc oxide possesses high transparency, increased electron mobility, smoothened surface, and lower work function. PTB7:PC{sub 71}BM inverted PSCs containing the modified ITO electrode achieved a high power conversion efficiency (PCE) of 8.49%, exceeding that of the control device containing a ZnO modified ITO electrode (7.48%). Especially, PCE-10:PC{sub 71}BM inverted polymer solar cells achieved a high PCE up to 9.4%. These results demonstrate a useful approach to improve the performance of inverted polymer solar cells.

  11. Porous copper zinc tin sulfide thin film as photocathode for double junction photoelectrochemical solar cells.

    PubMed

    Dai, Pengcheng; Zhang, Guan; Chen, Yuncheng; Jiang, Hechun; Feng, Zhenyu; Lin, Zhaojun; Zhan, Jinhua

    2012-03-21

    Porous copper zinc tin sulfide (CZTS) thin film was prepared via a solvothermal approach. Compared with conventional dye-sensitized solar cells (DSSCs), double junction photoelectrochemical cells using dye-sensitized n-type TiO(2) (DS-TiO(2)) as the photoanode and porous p-type CZTS film as the photocathode shows an increased short circuit current, external quantum efficiency and power conversion efficiency. PMID:22322239

  12. Enhancing the efficiency of SnS solar cells via band-offset engineering with a zinc oxysulfide buffer layer

    E-print Network

    solar cells. In this letter, we present a SnS device with a record power conversion efficiency of 2Enhancing the efficiency of SnS solar cells via band-offset engineering with a zinc oxysulfide as an NREL-certified total-area power-conversion efficiency of 2.04% and an uncertified active

  13. Co-solvent enhanced zinc oxysulfide buffer layers in Kesterite copper zinc tin selenide solar cells.

    PubMed

    Steirer, K Xerxes; Garris, Rebekah L; Li, Jian V; Dzara, Michael J; Ndione, Paul F; Ramanathan, Kannan; Repins, Ingrid; Teeter, Glenn; Perkins, Craig L

    2015-06-21

    A co-solvent, dimethylsulfoxide (DMSO), is added to the aqueous chemical "bath" deposition (CBD) process used to grow ZnOS buffer layers for thin film Cu2ZnSnSe4 (CZTSe) solar cells. Device performance improves markedly as fill factors increase from 0.17 to 0.51 upon the co-solvent addition. X-ray photoelectron spectroscopy (XPS) analyses are presented for quasi-in situ CZTSe/CBD-ZnOS interfaces prepared under an inert atmosphere and yield valence band offsets equal to -1.0 eV for both ZnOS preparations. When combined with optical band gap data, conduction band offsets exceed 1 eV for the water and the water/DMSO solutions. XPS measurements show increased downward band bending in the CZTSe absorber layer when the ZnOS buffer layer is deposited from water only. Admittance spectroscopy data shows that the ZnOS deposited from water increases the built-in potential (Vbi) yet these solar cells perform poorly compared to those made with DMSO added. The band energy offsets imply an alternate form of transport through this junction. Possible mechanisms are discussed, which circumvent the otherwise large conduction band spike between CZTSe and ZnOS, and improve functionality with the low-band gap absorber, CZTSe (Eg = 0.96 eV). PMID:26000570

  14. Evaluation of Potential Oxidative Stress in Egyptian Patients with Acute Zinc Phosphide Poisoning and the Role of Vitamin C

    PubMed Central

    Sagah, Ghada A.; Oreby, Merfat M.; El-Gharbawy, Rehab M.; Ahmed Fathy, Amal S.

    2015-01-01

    Objective To evaluate potential oxidative stress in patients with acute phosphide poisoning and the effect of vitamin C. Methods Participants were females and divided into three groups; group I: healthy volunteers group II: healthy volunteers received vitamin C, group III: patients with acute phosphide poisoning received the supportive and symptomatic treatment and group IV: patients with acute phosphide poisoning received the supportive and symptomatic treatment in addition to vitamin C. All the participants were subjected to thorough history, clinical examination, ECG and laboratory investigations were carried on collected blood and gastric lavage samples on admission. Blood samples were divided into two parts, one for measurement of routine investigations and the second part was used for evaluation of malondialdehyde and total thiol levels before and after receiving the treatment regimen. Results Most of the cases in this study were among the age group of 15–25 years, females, single, secondary school education, from rural areas and suicidal. All vital signs were within normal range and the most common complaint was vomiting and abdominal pain. All cases in this study showed normal routine investigations. The mean MDA levels after receiving treatment decreased significantly in groups II and IV. The mean total thiol levels increased significantly after receiving treatment in groups II and IV. Conclusion It can be concluded that vitamin C has a potential benefit due to its antioxidant property on zinc phosphide induced-oxidative stress in acute zinc phosphide poisoned patients. PMID:26715917

  15. Synthesis of highly crystalline Ga-doped zinc-oxide nanoparticles for hybrid polymer solar cells

    NASA Astrophysics Data System (ADS)

    Park, Hye-Jeong; Lee, Kang Hyuck; Sameera, Ivaturi; Kim, Sang-Woo

    2015-05-01

    Gallium (Ga)-doped zinc-oxide (ZnO) nanoparticles (NPs) were synthesized by using a polymer pyrolysis method. The smallest size of the obtained 4-mol% Ga-doped zinc-oxide (GZO) spherical NPs was approximately 10-15 nm, and the presence of Ga was confirmed by using X-ray photoelectron spectroscopy. To examine the role of GZO NPs, fabricated hybrid polymer solar cells (HPSCs) by using blends of a conjugated polymer poly (3-hexalthiophene) as an electron donor and crystalline GZO NPs as an electron acceptor. Significant improvements in the short-circuit current density and fill factor compared to these for the undoped ZnO (UZO) NPs were achieved by using the GZO NPs. This suggests that the GZO NPs have higher electron mobility than the UZO NPs and possess great potential for use as electron acceptor in HPSCs.

  16. Inverted polymer solar cells with amorphous indium zinc oxide as the electron-collecting electrode

    SciTech Connect

    Cheun, Hyeunseok; Kim, Jungbae; Zhou, Yinhua; Fang, Yunnan; Dindar, Amir; Shim, Jae Won; Fuentes-Hernandez, Canek; Sandhage, Kenneth H.; Kippelen, Bernard

    2010-09-17

    We report on the fabrication and performance of polymer-based inverted solar cells utilizing amorphous indium zinc oxide (a-IZO) as the electron-collecting electrode. Amorphous IZO films of 200 nm thickness were deposited by room temperature sputtering in a high-purity argon atmosphere. The films possessed a high optical transmittance in the visible region (? 80%), a low resistivity (3.3 × 10-4 ?cm), a low surface roughness (root mean square = 0.68 nm), and a low work function (4.46 ± 0.02 eV). Inverted solar cells with the structure a-IZO/P3HT: PCBM/PEDOT:PSS/Ag exhibited a power conversion efficiency of 3% estimated for AM 1.5G, 100 mW/cm2 illumination.

  17. Inverted polymer solar cells with amorphous indium zinc oxide as the electron-collecting electrode.

    PubMed

    Cheun, Hyeunseok; Kim, Jungbae; Zhou, Yinhua; Fang, Yunnan; Dindar, Amir; Shim, Jaewon; Fuentes-Hernandez, Canek; Sandhage, Kenneth H; Kippelen, Bernard

    2010-11-01

    We report on the fabrication and performance of polymer-based inverted solar cells utilizing amorphous indium zinc oxide (a-IZO) as the electron-collecting electrode. Amorphous IZO films of 200 nm thickness were deposited by room temperature sputtering in a high-purity argon atmosphere. The films possessed a high optical transmittance in the visible region (? 80%), a low resistivity (3.3 × 10?? ?cm), a low surface roughness (root mean square = 0.68 nm), and a low work function (4.46 ± 0.02 eV). Inverted solar cells with the structure a-IZO/P3HT: PCBM/PEDOT:PSS/Ag exhibited a power conversion efficiency of 3% estimated for AM 1.5G, 100 mW/cm² illumination. PMID:21165082

  18. Novel planar binuclear zinc phthalocyanine sensitizer for dye-sensitized solar cells: Synthesis and spectral, electrochemical, and photovoltaic properties

    NASA Astrophysics Data System (ADS)

    Zhu, Baiqing; Zhang, Xuejun; Han, Mingliang; Deng, Pengfei; Li, Qiaoling

    2015-01-01

    A planar binuclear zinc phthalocyanine was newly synthesized for use in dye-sensitized solar cells, based on Schiff base and asymmetric amino zinc phthalocyanine. The novel compounds were characterized using FTIR, UV-Vis, 1H NMR, cyclic voltammetry and elemental analysis. From the reduction and oxidation behavior, it is proved that APC and bi-NPC have negative LUMO levels and positive HOMO levels, satisfying the energy gap rule, and can be employed as sensitizers for dye-sensitized solar cells (DSSCs) applications.

  19. Fabrication and characterization of P3HT:PCBM-based thin film organic solar cells with zinc phthalocyanine

    NASA Astrophysics Data System (ADS)

    Maruhashi, Haruto; Oku, Takeo; Suzuki, Atsushi; Akiyama, Tsuyoshi; Yamasaki, Yasuhiro

    2015-02-01

    [6,6]-phenyl C61-butyric acid methyl ester and poly(3-hexylthiophene) bulk heterojunction solar cells added with zinc-tetra-tertiary-butyl-phthalocyanine (ZnPc) were fabricated and characterized. The photovoltaic properties of the solar cells with an inverted structure were improved by the ZnPc addition, which were investigated on the bases of current density-voltage characteristics, incident photon to current conversion efficiency.

  20. Fabrication and characterization of P3HT:PCBM-based thin film organic solar cells with zinc phthalocyanine

    SciTech Connect

    Maruhashi, Haruto Oku, Takeo Suzuki, Atsushi Akiyama, Tsuyoshi; Yamasaki, Yasuhiro

    2015-02-27

    [6,6]–phenyl C{sub 61}–butyric acid methyl ester and poly(3–hexylthiophene) bulk heterojunction solar cells added with zinc–tetra–tertiary–butyl–phthalocyanine (ZnPc) were fabricated and characterized. The photovoltaic properties of the solar cells with an inverted structure were improved by the ZnPc addition, which were investigated on the bases of current density–voltage characteristics, incident photon to current conversion efficiency.

  1. Mixed metal oxides for dye-sensitized solar cell using zinc titanium layered double hydroxide as precursor

    NASA Astrophysics Data System (ADS)

    Liu, Jianqiang; Qin, Yaowei; Zhang, Liangji; Xiao, Hongdi; Song, Jianye; Liu, Dehe; Leng, Mingzhe; Hou, Wanguo; Du, Na

    2013-12-01

    Mixed metal oxides (MMO) are always obtained from layered double hydroxide (LDH) by thermal decomposition. In the present work, a zinc titanium LDH with the zinc titanium molar ratio of 4.25 was prepared by urea method and ZnO-based mixed oxides were obtained by calcining at or over 500°C. The MMO was used as electrodes for dye sensitized solar cell (DSSC). The cells constructed by films of prepared composite materials using a N719 as dye were prepared. The efficiency values of these cells are 0.691%, 0.572% and 0.302% with MMO prepared at 500, 600 and 700°C, respectively.

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

    PubMed

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

    2015-10-01

    Recently, hybrid nanocomposites consisting of graphene/nanomaterial heterostructures have emerged as promising candidates for the fabrication of optoelectronic devices. In this work, we have employed a facile and in situ solution-based process to prepare zinc oxide/graphene quantum dots (ZnO/G QDs) in a hybrid structure. The prepared hybrid dots are composed of a ZnO core, with an average size of 5 nm, warped with graphene nanosheets. Spectroscopic studies show that the graphene shell quenches the photoluminescence intensity of the ZnO nanocrystals by about 72%, primarily due to charge transfer reactions and static quenching. A red shift in the absorption peak is also observed. Raman spectroscopy determines G-band splitting of the graphene shell into two separated sub-bands (G(+), G(-)) caused by the strain induced symmetry breaking. It is shown that the hybrid ZnO/G QDs can be used as a counter-electrode for heterojunction colloidal quantum-dot solar cells for efficient charge-carrier collection, as evidenced by the external quantum efficiency measurement. Under the solar simulated spectrum (AM 1.5G), we report enhanced power conversion efficiency (35%) with higher short current circuit (80%) for lead sulfide-based solar cells as compared to devices prepared by pristine ZnO nanocrystals. PMID:26339693

  3. Design of a Three-Layer Antireflection Coating for High Efficiency Indium Phosphide Solar Cells Using a Chemical Oxide as First Layer

    NASA Technical Reports Server (NTRS)

    Moulot, Jacques; Faur, Mircea; Faur, Maria; Goradia, Chandra; Goradia, Manju; Bailey, Sheila

    1995-01-01

    It is well known that the behavior of III-V compound based solar cells is largely controlled by their surface, since the majority of light generated carriers (63% for GaAs and 79% for InP) are created within 0.2 microns of the illuminated surface of the cell. Consequently, the always observed high surface recombination velocity (SRV) on these cells is a serious limiting factor for their high efficiency performance, especially for those with the p-n junction made by either thermal diffusion or ion implantation. A good surface passivation layer, ideally, a grown oxide as opposed to a deposited one, will cause a significant reduction in the SRV without adding interface problems, thus improving the performance of III-V compound based solar cells. Another significant benefit to the overall performance of the solar cells can be achieved by a substantial reduction of their large surface optical reflection by the use of a well designed antireflection (AR) coating. In this paper, we demonstrate the effectiveness of using a chemically grown, thermally and chemically stable oxide, not only for surface passivation but also as an integral part of a 3- layer AR coating for thermally diffused p(+)n InP solar cells. A phosphorus-rich interfacial oxide, In(PO3)3, is grown at the surface of the p(+) emitter using an etchant based on HNO3, o-H3PO4 and H2O2. This oxide has the unique properties of passivating the surface as well as serving as a fairly efficient antireflective layer yielding a measured record high AM0, 25 C, open-circuit voltage of 890.3 mV on a thermally diffused InP(Cd,S) solar cell. Unlike conventional single layer AR coatings such as ZnS, Sb2O3, SiO or double layer AR coatings such as ZnS/MgF2 deposited by e-beam or resistive evaporation, this oxide preserves the stoichiometry of the InP surface. We show that it is possible to design a three-layer AR coating for a thermally diffused InP solar cell using the In(PO3)3 grown oxide as the first layer and Al2O3, MgF2 or ZnS, MgF2 as the second and third layers respectively, so as to yield an overall theoretical reflectance of less than 2%. Since chemical oxides are readily grown on III-V semiconductor materials, the technique of using the grown oxide layer to both passivate the surface as well as serve as the first of a multilayer AR coating, should work well for essentially all III-V compound-based solar cells.

  4. Design of a three-layer antireflection coating for high efficiency indium phosphide solar cells using a chemical oxide as first layer

    NASA Technical Reports Server (NTRS)

    Moulot, Jacques; Faur, M.; Faur, M.; Goradia, C.; Goradia, M.; Bailey, S.

    1995-01-01

    It is well known that the behavior of III-V compound based solar cells is largely controlled by their surface, since the majority of light generated carriers (63% for GaAs and 79% for InP) are created within 0.2 mu m of the surface of the illuminated cell. Consequently, the always observed high surface recombination velocity (SRV) on these cells is a serious limiting factor for their high efficiency performance, especially for those with p-n junction made by either thermal diffusion or ion implantation. A good surface passivation layer, ideally a grown oxide as opposed to a deposited one, will cause a significant reduction in the SRV without adding interface problems, thus improving the performance of III-V compound based solar cells. Another significant benefit to the overall performance of the solar cells can be achieved by a substantial reduction of their large surface optical reflection by the use of a well designed antireflection (AR) coating. In this paper, we demonstrate the effectiveness of using a chemically grown thermally and chemically stable oxide, not only for surface passivation but also as an integral part of a 3-layer AR coating for thermally diffused p+n InP solar cells. A phosphorus-rich interfacial oxide, In(PO3)3, is grown at the surface of the p+ emitter using an etchant based on HNO3, o-H3PO4 and H2O2. This oxide has the unique properties of passivating the surface as well as serving as an efficient antireflective layer yielding a measured record high AMO open-circuit voltage of 890.3 mV on a thermally diffused InP(Cd,S) solar cell. Unlike conventional single layer AR coatings such as ZnS, Sb2O3, SiO or double layer AR coatings such as ZnS/MgF2 deposited by e-beam or resistive evaporation, this oxide preserves the stoichiometry of the InP surface. We show that it is possible to design a three-layer AR coating for a thermally diffused InP solar cell using the In(PO3)3 grown oxide as the first layer and Al2O3 and MgF2 as the second and third layers respectively, so as to yield an overall theoretical reflectance of less than 2%. Since chemical oxides are readily grown on III-V semiconductors materials, the technique of using the grown oxide layer to both passivate the surface as well as serve as the first of a multilayer AR coating should work well for all III-V compound-based solar cells.

  5. Design of a three-layer antireflection coating for high efficiency indium phosphide solar cells using a chemical oxide as first layer

    NASA Astrophysics Data System (ADS)

    Moulot, Jacques; Faur, M.; Faur, M.; Goradia, C.; Goradia, M.; Bailey, S.

    1995-10-01

    It is well known that the behavior of III-V compound based solar cells is largely controlled by their surface, since the majority of light generated carriers (63% for GaAs and 79% for InP) are created within 0.2 mu m of the surface of the illuminated cell. Consequently, the always observed high surface recombination velocity (SRV) on these cells is a serious limiting factor for their high efficiency performance, especially for those with p-n junction made by either thermal diffusion or ion implantation. A good surface passivation layer, ideally a grown oxide as opposed to a deposited one, will cause a significant reduction in the SRV without adding interface problems, thus improving the performance of III-V compound based solar cells. Another significant benefit to the overall performance of the solar cells can be achieved by a substantial reduction of their large surface optical reflection by the use of a well designed antireflection (AR) coating. In this paper, we demonstrate the effectiveness of using a chemically grown thermally and chemically stable oxide, not only for surface passivation but also as an integral part of a 3-layer AR coating for thermally diffused p+n InP solar cells. A phosphorus-rich interfacial oxide, In(PO3)3, is grown at the surface of the p+ emitter using an etchant based on HNO3, o-H3PO4 and H2O2. This oxide has the unique properties of passivating the surface as well as serving as an efficient antireflective layer yielding a measured record high AMO open-circuit voltage of 890.3 mV on a thermally diffused InP(Cd,S) solar cell. Unlike conventional single layer AR coatings such as ZnS, Sb2O3, SiO or double layer AR coatings such as ZnS/MgF2 deposited by e-beam or resistive evaporation, this oxide preserves the stoichiometry of the InP surface. We show that it is possible to design a three-layer AR coating for a thermally diffused InP solar cell using the In(PO3)3 grown oxide as the first layer and Al2O3 and MgF2 as the second and third layers respectively, so as to yield an overall theoretical reflectance of less than 2%. Since chemical oxides are readily grown on III-V semiconductors materials, the technique of using the grown oxide layer to both passivate the surface as well as serve as the first of a multilayer AR coating should work well for all III-V compound-based solar cells.

  6. Semitransparent polymer-based solar cells with aluminum-doped zinc oxide electrodes.

    PubMed

    Wilken, Sebastian; Wilkens, Verena; Scheunemann, Dorothea; Nowak, Regina-Elisabeth; von Maydell, Karsten; Parisi, Jürgen; Borchert, Holger

    2015-01-14

    With the use of two transparent electrodes, organic polymer-fullerene solar cells are semitransparent and may be combined to parallel-connected multijunction devices or used for innovative applications like power-generating windows. A challenging issue is the optimization of the electrodes, to combine high transparency with adequate electric properties. In the present work, we study the potential of sputter-deposited aluminum-doped zinc oxide as an alternative to the widely used but relatively expensive indium tin oxide (ITO) as cathode material in semitransparent polymer-fullerene solar cells. Concerning the anode, we utilized an insulator-metal-insulator structure based on ultrathin Au films embedded between two evaporated MoO3 layers, with the outer MoO3 film (capping layer) serving as a light coupling layer. The performance of the ITO-free semitransparent polymer-fullerene solar cells was systematically studied as dependent on the thickness of the capping layer and the active layer as well as the illumination direction. These variations were found to have strong impact on the obtained photocurrent densities. We performed optical simulations of the electric field distribution within the devices using the transfer-matrix method, to analyze the origin of the current density variations in detail and provide deep insight into the device physics. With the conventional absorber materials studied here, optimized ITO-free and semitransparent devices reached 2.0% power conversion efficiency and a maximum optical transmission of 60%, with the device concept being potentially transferable to other absorber materials. PMID:25495167

  7. Design of Zinc Oxide Based Solid-State Excitonic Solar Cell with Improved Efficiency 

    E-print Network

    Lee, Tao Hua

    2012-02-14

    Excitonic photovoltaic devices, including organic, hybrid organic/inorganic, and dye-sensitized solar cells, are attractive alternatives to conventional inorganic solar cells due to their potential for low cost and low temperature solution...

  8. InP (Indium Phosphide): Into the future

    NASA Technical Reports Server (NTRS)

    Brandhorst, Henry W., Jr.

    1989-01-01

    Major industry is beginning to be devoted to indium phosphide and its potential applications. Key to these applications are high speed and radiation tolerance; however the high cost of indium phosphide may be an inhibitor to progress. The broad applicability of indium phosphide to many devices will be discussed with an emphasis on photovoltaics. Major attention is devoted to radiation tolerance and means of reducing cost of devices. Some of the approaches applicable to solar cells may also be relevant to other devices. The intent is to display the impact of visionary leadership in the field and enable the directions and broad applicability of indium phosphide.

  9. Anti-reflection zinc oxide nanocones for higher efficiency thin-film silicon solar cells

    E-print Network

    Mailoa, Jonathan P

    2012-01-01

    Thin film silicon solar cells, which are commonly made from microcrystalline silicon ([mu]c-Si) or amorphous silicon (a-Si), have been considered inexpensive alternatives to thick polycrystalline silicon (polysilicon) solar ...

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

    SciTech Connect

    Chu, T.L.

    1992-04-01

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

  11. Nickel-zinc cell

    SciTech Connect

    Jones, R.A.

    1982-11-09

    A long-lived, nickel-zinc cell is disclosed which is characterized by a zinc electrode having a copper grid and an active material comprising zinc-rich particles, calcium-rich particles and an entanglement of cellulose fibers for irrigating the mix and supporting Cazincate formation and persistance. Lead compounds may be added for improved turn around efficiency and reduced H/sub 2/O loss.

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

    NASA Technical Reports Server (NTRS)

    Barnett, Allen M. (Inventor)

    1985-01-01

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

  13. ZINC ROUGHER CELLS ON LEFT, ZINC CLEANER CELLS ON RIGHT, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ZINC ROUGHER CELLS ON LEFT, ZINC CLEANER CELLS ON RIGHT, LOOKING NORTH. NOTE ONE STYLE OF DENVER AGITATOR IN LOWER RIGHT CELL. - Shenandoah-Dives Mill, 135 County Road 2, Silverton, San Juan County, CO

  14. Efficient inverted polymer solar cells based on ultrathin aluminum interlayer modified aluminum-doped zinc oxide electrode

    NASA Astrophysics Data System (ADS)

    Shi, Ting; Zhu, Xiaoguang; Tu, Guoli

    2014-03-01

    A convenient and economical design for inverted polymer solar cells has been developed by introducing an ultrathin aluminium (Al) interlayer to modify aluminum-doped zinc oxide (AZO) electrode as the bottom cathode. An ultrathin interlayer of Al could lower the work function of AZO electrode. Power conversion efficiency (PCE) of 3.84% was obtained for poly(3-hexyl-thiophene):phenyl-C61-butyric acid methyl ester based device and that of poly(3-hexyl-thiophene):indene-C60 bisadduct based device with such electrodes could reach to 5.52%, which was much higher than the structurally identical device based on ITO/Al(1 nm) electrode and almost the same as that of the conventional device. This indicates that the ultrathin Al modified AZO composite electrode is a strong competitor for the cathode in inverted polymer solar cells especially the large scale and low costs devices.

  15. Silicon nanowire arrays coupled with cobalt phosphide spheres as low-cost photocathodes for efficient solar hydrogen evolution.

    PubMed

    Bao, Xiao-Qing; Fatima Cerqueira, M; Alpuim, Pedro; Liu, Lifeng

    2015-07-01

    We demonstrate the first example of silicon nanowire array photocathodes coupled with hollow spheres of the emerging earth-abundant cobalt phosphide catalysts. Compared to bare silicon nanowire arrays, the hybrid electrodes exhibit significantly improved photoelectrochemical performance toward the solar-driven H2 evolution reaction. PMID:26050844

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

    SciTech Connect

    Lange, Ilja; Reiter, Sina; Kniepert, Juliane; Piersimoni, Fortunato; Brenner, Thomas; Neher, Dieter; Pätzel, Michael; Hildebrandt, Jana; Hecht, Stefan

    2015-03-16

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

  17. Salicylic acid as a tridentate anchoring group for azo-bridged zinc porphyrin in dye-sensitized solar cells.

    PubMed

    Gou, Faliang; Jiang, Xu; Li, Bo; Jing, Huanwang; Zhu, Zhenping

    2013-12-11

    Two series dyes of azo-bridged zinc porphyrins have been devised, synthesized, and performed in dye-sensitized solar cells, in which salicylic acids and azo groups were introduced as a new anchoring group and ?-conjugated bridge via a simple synthetic procedure. The representation of the new dyes has been investigated by optical, photovoltaic, and electrochemical means. The photoelectric conversion efficiency of their DSSC devices has been improved compared with other DSSC devices sensitized by symmetrical porphyrin dyes. The results revealed that tridentate binding modes between salicylic acid and TiO2 nanoparticles could enhance the efficiency of electron injection. The binding modes between salicylic acid and TiO2 nanoparticles may play a crucial role in the photovoltaic performance of DSSCs. PMID:24229086

  18. Ink jet printable silver metallization with zinc oxide for front side metallization for micro crystalline silicon solar cells

    NASA Astrophysics Data System (ADS)

    Jurk, Robert; Fritsch, Marco; Eberstein, Markus; Schilm, Jochen; Uhlig, Florian; Waltinger, Andreas; Michaelis, Alexander

    2015-12-01

    Ink jet printable water based inks are prepared by a new silver nanoparticle synthesis and the addition of nanoscaled ZnO particles. For the formation of front side contacts the inks are ink jet printed on the front side of micro crystalline silicon solar cells, and contact the cell directly during the firing step by etching through the wafers’ anti-reflection coating (ARC). In terms of Ag dissolution and precipitation the mechanism of contact formation can be compared to commercial glass containing thick film pastes. This avoids additional processing steps, like laser ablation, which are usually necessary to open the ARC prior to ink jet printing. As a consequence process costs can be reduced. In order to optimize the ARC etching and contact formation during firing, zinc oxide nanoparticles are investigated as an ink additive. By utilization of in situ contact resistivity measurements the mechanism of contacting was explored. Our results show that silver inks containing ZnO particles realize a specific contact resistance below 10 m??cm2. By using a multi-pass ink jet printing and plating process a front side metallization of commercial 6??×??6 inch2 standard micro crystalline silicone solar cells with emitter resistance of 60 ?/? was achieved and showed an efficiency of 15.7%.

  19. Effect of the filtration of PbI2 solution for zinc oxide nanowire based perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Mijanur Rahman, Md.; Uekawa, Naofumi; Shiba, Fumiyuki; Okawa, Yusuke; Sakai, Masatoshi; Yamamoto, Kazunuki; Kudo, Kazuhiro; Konishi, Takehisa

    2016-01-01

    Zinc oxide (ZnO) nanowires (NWs) are grown on fluorine-doped tin oxide (FTO) glass substrates via a simple reactive evaporation method without the presence of any catalysts or additives. The ZnO NWs show high crystallinity and preferential elongation along the c-axis of the hexagonal wurtzite crystal structure. The highly crystalline NWs as electron transporting layer have been used to fabricate the CH3NH3PbI3 perovskite solar cells and their photovoltaic performance were investigated. In this report, we studied the effect of filtration of PbI2-solution on surface morphology of CH3NH3PbI3 layer. Spin-coating of the filtered PbI2-solution leads to a better crystallization and relatively homogenous coverage of the CH3NH3PbI3 film, resulting in an enhancement of the solar cell efficiency compared to the cell fabricated using non-filtrated PbI2-solution. By synthesizing the CH3NH3PbI3 film using filtrated PbI2-solution, we achieved the best power conversion efficiency of 4.8% with a current density of 7.6 mA cm?2, the open circuit voltage of 0.79 V and fill factor of 0.63.

  20. Solar Energy Materials & Solar Cells 91 (2007) 924930 Plasma-enhanced chemical vapor deposition of zinc oxide at

    E-print Network

    Hicks, Robert F.

    2007-01-01

    of zinc oxide at atmospheric pressure and low temperature M.D. Barankin, E. Gonzalez II, A.M. Ladwig, R vapor deposition of aluminum-doped zinc oxide has been demonstrated for the first time at 800 Torr reserved. Keywords: Transparent-conducting oxide (TCO); Al/ZnO; PECVD 1. Introduction Aluminum-doped zinc

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

    SciTech Connect

    Rohatgi, A.; Sudharsanan, R.; Ringel, S.A.; Chou, H.C. )

    1992-10-01

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

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

    SciTech Connect

    Rohatgi, A.; Sudharsanan, R.; Ringel, S. )

    1992-02-01

    This report describes research into polycrystalline CdTe solar cells grown by metal-organic chemical vapor deposition. Efficiencies of {approximately}10% were achieved using both p-i-n and p-n structures. A pre-heat treatment of CdS/SnO{sub 2}/glass substrates at 450{degrees}C in hydrogen atmosphere prior to the CdTe growth was found to be essential for high performance because this heat treatment reduces oxygen-related defects from the CdS surface. However, this treatment also resulted in a Cd-deficient CdS surface, which may in part limit the CdTe cell efficiency to 10% due to Cd vacancy-related interface defects. Preliminary model calculations suggest that removing these states can increase the cell efficiency from 10% to 13.5%. Photon absorption in the CdS film also limits the cell performance, and eliminating this loss mechanism can result in CdTe efficiencies in excess of 18%. Polycrystalline, 1.7-e, CdZnTe films were also grown for tandem-cell applications. CdZnTe/CdS cells processed using the standard CdTe cell fabrication procedure resulted in 4.4% efficiency, high series resistance, and a band-gap shift to 1.55 eV. The formation of Zn-O at and near the CdZnTe surface is the source of high contact resistance. A saturated dichromate each prior to contact deposition was found to solve the contact resistance problem. The CdCl{sub 2} treatment was identified as the cause of the observed band-gap shift due to the preferred formation of ZnCl{sub 2}. 59 refs.

  3. A review of episodes of zinc phosphide toxicosis in wild geese (Branta spp.) in Oregon (2004?2011)

    USGS Publications Warehouse

    Bildfell, Rob J.; Rumbeiha, Wilson K.; Schuler, Krysten L.; Meteyer, Carol U.; Wolff, Peregrine L.; Gillin, Colin M.

    2013-01-01

    Epizootic mortality in several geese species, including cackling geese (Branta hutchinsii) and Canada geese (Branta canadensis), has been recognized in the Willamette Valley of Oregon for over a decade. Birds are generally found dead on a body of water or are occasionally observed displaying neurologic clinical signs such as an inability to raise or control the head prior to death. Investigation of these epizootic mortality events has revealed the etiology to be accidental poisoning with the rodenticide zinc phosphide (Zn3P2). Gross and histologic changes are restricted to acute pulmonary congestion and edema, sometimes accompanied by distension of the upper alimentary tract by fresh grass. Geese are unusually susceptible to this pesticide; when combined with an epidemiologic confluence of depredation of specific agricultural crops by rodents and seasonal avian migration pathways, epizootic toxicosis may occur. Diagnosis requires a high index of suspicion, appropriate sample collection and handling, plus specific test calibration for this toxicant. Interagency cooperation, education of farmers regarding pesticide use, and enforcement of regulations has been successful in greatly decreasing these mortality events since 2009.

  4. Dye-sensitized solar cell employing zinc oxide aggregates grown in the presence of lithium

    DOEpatents

    Zhang, Qifeng; Cao, Guozhong

    2013-10-15

    Provided are a novel ZnO dye-sensitized solar cell and method of fabricating the same. In one embodiment, deliberately added lithium ions are used to mediate the growth of ZnO aggregates. The use of lithium provides ZnO aggregates that have advantageous microstructure, morphology, crystallinity, and operational characteristics. Employing lithium during aggregate synthesis results in a polydisperse collection of ZnO aggregates favorable for porosity and light scattering. The resulting nanocrystallites forming the aggregates have improved crystallinity and more favorable facets for dye molecule absorption. The lithium synthesis improves the surface stability of ZnO in acidic dyes. The procedures developed and disclosed herein also help ensure the formation of an aggregate film that has a high homogeneity of thickness, a high packing density, a high specific surface area, and good electrical contact between the film and the fluorine-doped tin oxide electrode and among the aggregate particles.

  5. Dye-sensitized solar cell characteristics of nanocomposite zinc ferrite working electrode: effect of composite precursors and titania as a blocking layer on photovoltaic performance.

    PubMed

    Habibi, Mohammad Hossein; Habibi, Amir Hossein; Zendehdel, Mahmoud; Habibi, Mehdi

    2013-06-01

    This research investigates the performance of a zinc ferrite (ZF) as working electrodes in a dye-sensitized solar cell (DSSC). This ZF working electrode was prepared by sol-gel and thermal decomposition of four different precursors including: zinc acetate dihydrate (Zn(CH3COO)2·2H2O), ferric nitrate nonahydrate (Fe(NO3)3·9H2O), iron(III) acetate; Fe(C2H3O2)3, and zinc nitrate hexahydrate, Zn(NO3)2·6H2O. The effects of annealing temperature and precursors on the structural, morphological, and optical properties were investigated. The field emission scanning electron microscope images (FESEM) and scanning electron microscopy (SEM) show that ZFe films are polycrystalline in nature and homogeneous with densely packed grains. Nanoporous zinc ferrite coatings were prepared by doctor blade technique on the fluorine-doped tin oxide (FTO) and used as working electrodes in DSSC. In all DSSCs, platinized FTO and [Co(bpy)3](2+/3+) in 3-methoxy proponitrile were used as counter electrode and redox mediator system respectively. Comparing the fill factors of four different zinc ferrite nanocomposites, the highest fill factor was for ZnFe2O4-TBL sample. Cell fabricated with ZnFeA working electrode shows relatively higher Jsc. PMID:23571086

  6. Highly porous Zinc Stannate (Zn2SnO4) nanofibers scaffold photoelectrodes for efficient methyl ammonium halide perovskite solar cells

    PubMed Central

    Mali, Sawanta S.; Su Shim, Chang; Kook Hong, Chang

    2015-01-01

    Development of ternary metal oxide (TMO) based electron transporting layer (ETL) for perovskite solar cell open a new approaches toward efficient a unique strategy for solid state dye-sensitized solar cells (ssDSSCs). In the present investigation, highly porous zinc tin oxide (Zn2SnO4) scaffold nanofibers has been synthesized by electrospinning technique and successfully used for methyl ammonium lead halide (CH3NH3PbI3) perovskite sensitized solid state solar cells. The fabricated optimized perovskite solar cell devices exhibited 7.38% power conversion efficiency (PCE) with open circuit voltage (VOC) 0.986?V, current density (JSC)?=?12.68?mAcm-2 and fill factor (FF) 0.59 under AM 1.5?G sunlight (100?mWcm?2) which is higher than Zn2SnO4 nanoparticle (??=?2.52%) based perovskite solar cells. This improvement is achieved due to high porosity of Zn2SnO4 nanofibers and high crystallinity of the nanofibers synthesized at 700?°C. These results are remarkably higher than reported perovskite solar cells based on such type of ternary metal oxide ETLs. PMID:26094863

  7. Highly porous Zinc Stannate (Zn2SnO4) nanofibers scaffold photoelectrodes for efficient methyl ammonium halide perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Mali, Sawanta S.; Su Shim, Chang; Kook Hong, Chang

    2015-06-01

    Development of ternary metal oxide (TMO) based electron transporting layer (ETL) for perovskite solar cell open a new approaches toward efficient a unique strategy for solid state dye-sensitized solar cells (ssDSSCs). In the present investigation, highly porous zinc tin oxide (Zn2SnO4) scaffold nanofibers has been synthesized by electrospinning technique and successfully used for methyl ammonium lead halide (CH3NH3PbI3) perovskite sensitized solid state solar cells. The fabricated optimized perovskite solar cell devices exhibited 7.38% power conversion efficiency (PCE) with open circuit voltage (VOC) 0.986?V, current density (JSC)?=?12.68?mAcm-2 and fill factor (FF) 0.59 under AM 1.5?G sunlight (100?mWcm-2) which is higher than Zn2SnO4 nanoparticle (??=?2.52%) based perovskite solar cells. This improvement is achieved due to high porosity of Zn2SnO4 nanofibers and high crystallinity of the nanofibers synthesized at 700?°C. These results are remarkably higher than reported perovskite solar cells based on such type of ternary metal oxide ETLs.

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

    SciTech Connect

    Rohatgi, A.; Summers, C.J.; Erbil, A.; Sudharsanan, R.; Ringel, S. . School of Electrical Engineering)

    1990-10-01

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

  9. Ultrathin amorphous zinc-tin-oxide buffer layer for enhancing heterojunction interface quality in metal-oxide solar cells

    E-print Network

    Heo, Jaeyeong

    We demonstrate a tunable electron-blocking layer to enhance the performance of an Earth-abundant metal-oxide solar-cell material. A 5 nm thick amorphous ternary metal-oxide buffer layer reduces interface recombination, ...

  10. Gallium phosphide energy converters

    NASA Technical Reports Server (NTRS)

    Sims, P. E.; Dinetta, L. C.; Goetz, M. A.

    1995-01-01

    Gallium phosphide (GaP) energy converters may be successfully deployed to provide new mission capabilities for spacecraft. Betavoltaic power supplies based on the conversion of tritium beta decay to electricity using GaP energy converters can supply long term low-level power with high reliability. High temperature solar cells, also based on GaP, can be used in inward-bound missions greatly reducing the need for thermal dissipation. Results are presented for GaP direct conversion devices powered by Ni-63 and compared to the conversion of light emitted by tritiarated phosphors. Leakage currents as low as 1.2 x 10(exp -17) A/sq cm have been measured and the temperature dependence of the reverse saturation current is found to have ideal behavior. Temperature dependent IV, QE, R(sub sh), and V(sub oc) results are also presented. These data are used to predict the high-temperature solar cell and betacell performance of GaP devices and suggest appropriate applications for the deployment of this technology.

  11. Efficient and ultraviolet durable inverted organic solar cells based on an aluminum-doped zinc oxide transparent cathode

    NASA Astrophysics Data System (ADS)

    Liu, Hanxiao; Wu, Zhenghui; Hu, Jianqiao; Song, Qunliang; Wu, Bo; Lam Tam, Hoi; Yang, Qingyi; Hong Choi, Wing; Zhu, Furong

    2013-07-01

    High performance inverted bulk heterojunction organic solar cells (OSCs), based on the blend of poly[[4,8-bis[(2-ethylhexyl)oxy] benzo [1,2-b:4,5-b'] dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl

  12. Zinc Oxide Modified with Benzylphosphonic Acids as Transparent Electrodes in Regular and Inverted Organic Solar Cell Structures

    E-print Network

    Ilja Lange; Sina Reiter; Juliane Kniepert; Fortunato Piersimoni; Michael Paetzel; Jana Hildebrandt; Thomas Brenner; Stefan Hecht; Dieter Neher

    2015-02-05

    An approach is presented to modify the WF of solution-processed sol-gel derived ZnOover an exceptionally wide range of more than 2.3 eV. This approach relies on the formation of dense and homogeneous self-assembled monolayers based on phosphonic acids with different dipole moments. This allows us to apply ZnO as charge selective bottom electrodes in either regular or inverted solar cell structures, using P3HT:PCBM as the active layer. These devices compete with or even exceed the performance of the reference cell on ITO/PEDOT:PSS. Our finding challenges the current view that bottom electrodes in inverted solar cells need to be electron-blocking for good device performance.

  13. Routes to copper zinc tin sulfide Cu2ZnSnS4 a potential material for solar cells.

    PubMed

    Ramasamy, Karthik; Malik, Mohammad A; O'Brien, Paul

    2012-06-11

    Power generation through photovoltaics (PV) has been growing at an average rate of 40% per year over the last decade; but has largely been fuelled by conventional Si-based technologies. Such cells involve expensive processing and many alternatives use either toxic, less-abundant and or expensive elements. Kesterite Cu(2)ZnSnS(4) (CZTS) has been identified as a solar energy material composed of both less toxic and more available elements. Power conversion efficiencies of 8.4% (vacuum processing) and 10.1% (non-vacuum processing) from cells constructed using CZTS have been achieved to date. In this article, we review various deposition methods for CZTS thin films and the synthesis of CZTS nanoparticles. Studies of direct relevance to solar cell applications are emphasised and characteristic properties are collated. PMID:22531115

  14. Preparation of n-ZnO/ p-Si solar cells by oxidation of zinc nanoparticles: effect of oxidation temperature on the photovoltaic properties

    NASA Astrophysics Data System (ADS)

    Ismail, Raid A.; Al-Jawad, Selma M. H.; Hussein, Naba

    2014-12-01

    In this study, n-ZnO/ p-Si solar cells were fabricated by spraying ZnO nanoparticles (NPs) film synthesised by dissolving of high purity zinc in hydrogen peroxide H2O2 followed by thermal oxidation in air on p-type silicon substrates. The oxidation was carried out at different temperatures (200-500) °C. The crystalline structure of the ZnO NPs films was investigated by X-ray diffraction which indicated wurtzite structure films along (100) plane. The morphology of the NPs was studied by atomic force microscopy and scanning electron microscopy. The result showed an average grain size of ZnO NPs in the range of (72.7-95.8) nm and the surface roughness increasing with oxidation temperature. Three peaks located at ultraviolet, violet and green emission regions were noticed in the photoluminescence spectra of ZnO NPs. From optical studies, it was shown that the direct optical band gap is found to be in the range of (3.85-3.96) eV depended on the oxidation temperature. The synthesised ZnO films have n-type conductivity, and the mobility was in the range of (7-24) cm2 V-1 s-1. Current-voltage I- V and capacitance-voltage C- V of ZnO NPs/Si heterojunction solar cell were investigated as function of oxidation temperature. The spectral response of n-ZnO NPs/ p-Si solar cell showed two peaks of response and its maximum value approaching 0.62 mA W-1 at ? = 800 nm. Solar cell oxidized at 500 °C gave open circuit voltage V OC of 375 mV, short circuit current density J SC of 25 mA cm-2, a fill factor FF of 0.72, and conversion efficiency ? of 6.79 % under illumination of 100 mW cm-2.

  15. Comparative modeling of InP solar cell structures

    NASA Technical Reports Server (NTRS)

    Jain, R. K.; Weinberg, I.; Flood, D. J.

    1991-01-01

    The comparative modeling of p(+)n and n(+)p indium phosphide solar cell structures is studied using a numerical program PC-1D. The optimal design study has predicted that the p(+)n structure offers improved cell efficiencies as compared to n(+)p structure, due to higher open-circuit voltage. The various cell material and process parameters to achieve the maximum cell efficiencies are reported. The effect of some of the cell parameters on InP cell I-V characteristics was studied. The available radiation resistance data on n(+)p and p(+)p InP solar cells are also critically discussed.

  16. Wurtzite copper-zinc-tin sulfide as a superior counter electrode material for dye-sensitized solar cells.

    PubMed

    Kong, Jun; Zhou, Zheng-Ji; Li, Mei; Zhou, Wen-Hui; Yuan, Sheng-Jie; Yao, Rong-Yue; Zhao, Yang; Wu, Si-Xin

    2013-01-01

    Wurtzite and kesterite Cu2ZnSnS4 (CZTS) nanocrystals were employed as counter electrode (CE) materials for dye-sensitized solar cells (DSSCs). Compared to kesterite CZTS, the wurtzite CZTS exhibited higher electrocatalytic activity for catalyzing reduction of iodide electrolyte and better conductivity. Accordingly, the DSSC with wurtzite CZTS CE generated higher power conversion efficiency (6.89%) than that of Pt (6.23%) and kesterite CZTS (4.89%) CEs. PMID:24191954

  17. Wurtzite copper-zinc-tin sulfide as a superior counter electrode material for dye-sensitized solar cells

    PubMed Central

    2013-01-01

    Wurtzite and kesterite Cu2ZnSnS4 (CZTS) nanocrystals were employed as counter electrode (CE) materials for dye-sensitized solar cells (DSSCs). Compared to kesterite CZTS, the wurtzite CZTS exhibited higher electrocatalytic activity for catalyzing reduction of iodide electrolyte and better conductivity. Accordingly, the DSSC with wurtzite CZTS CE generated higher power conversion efficiency (6.89%) than that of Pt (6.23%) and kesterite CZTS (4.89%) CEs. PMID:24191954

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

    SciTech Connect

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

    2014-06-16

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

    Indium-tin-oxide (ITO) free inverted organic solar cells (IOSCs) based on aluminum-doped zinc oxide (AZO) cathode, low-temperature aqueous solution processed zinc oxide (ZnO) electron extraction layer, and poly(3-hexylthiophene-2, 5-diyl):[6, 6]-phenyl C61 butyric acid methyl ester blend were realized in this work. The resulted IOSC with ZnO annealed at 150 °C shows the superior power conversion efficiency (PCE) of 3.01%, if decreasing the ZnO annealing temperature to 100 °C, the obtained IOSC also shows a PCE of 2.76%, and no light soaking issue is observed. It is found that this ZnO film not only acts as an effective buffer layer but also slightly improves the optical transmittance of AZO substrates. Further, despite the relatively inferior air-stability, these un-encapsulated AZO/ZnO IOSCs show comparable PCEs to the referenced ITO/ZnO IOSCs, which demonstrates that the AZO cathode is a potential alternative to ITO in IOSCs. Meanwhile, this simple ZnO process is compatible with large area deposition and plastic substrates, and is promising to be widely used in IOSCs and other relative fields.

  20. Aluminum phosphide

    Integrated Risk Information System (IRIS)

    Aluminum phosphide ; CASRN 20859 - 73 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinoge

  1. Solar Cells

    NASA Technical Reports Server (NTRS)

    1983-01-01

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

  2. Application of patterned growth of aligned zinc oxide nanoarrays by mirocontact printing in quantum dots-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Deng, Jianping; Wang, Minqiang; Yang, Zhi; Liu, Jing; Sun, Zhongwang; Song, Xiaohui

    2015-04-01

    This paper describes a simple method for patterned growth of ZnO nanoarrays (NAs) that is based on a combination of the microcontact printing process for patterning ZnO seed films and the low-temperature hydrothermal approach for depositing ZnO NAs. The patterned ZnO seed films were achieved via printing patterned TiO2 sol on ZnO seed films. It is found that the pattern quality is mainly affected by the viscosity of TiO2 ink and the pressure including value and direction. To assess the possibility of patterned ZnO NAs applied to devices, the patterned ZnO NAs were used as light scattering layer in CdSe-sensitized solar cells. The diffuse-reflection, absorption and transmission spectra show that the patterned ZnO NAs greatly enhance the light scattering and absorbance in the visible range. The enhancement of cell performance is attributed to the patterned ZnO NAs: 1) multiple-light scattering improves the light absorbance, and 2) NAs with high electron mobility facilitate the electron collection.

  3. Acute changes in cellular zinc alters zinc uptake rates prior to zinc transporter gene expression in Jurkat cells.

    PubMed

    Holland, Tai C; Killilea, David W; Shenvi, Swapna V; King, Janet C

    2015-12-01

    A coordinated network of zinc transporters and binding proteins tightly regulate cellular zinc levels. Canonical responses to zinc availability are thought to be mediated by changes in gene expression of key zinc transporters. We investigated the temporal relationships of actual zinc uptake with patterns of gene expression in membrane-bound zinc transporters in the human immortalized T lymphocyte Jurkat cell line. Cellular zinc levels were elevated or reduced with exogenous zinc sulfate or N,N,N',N-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN), respectively. Excess zinc resulted in a rapid 44 % decrease in the rate of zinc uptake within 10 min. After 120 min, the expression of metallothionein (positive control) increased, as well as the zinc exporter, ZnT1; however, the expression of zinc importers did not change during this time period. Zinc chelation with TPEN resulted in a rapid twofold increase in the rate of zinc uptake within 10 min. After 120 min, the expression of ZnT1 decreased, while again the expression of zinc importers did not change. Overall, zinc transporter gene expression kinetics did not match actual changes in cellular zinc uptake with exogenous zinc or TPEN treatments. This suggests zinc transporter regulation may be the initial response to changes in zinc within Jurkat cells. PMID:26420239

  4. Indium-gallium-zinc-oxide layer used to increase light transmittance efficiency of adhesive layer for stacked-type multijunction solar cells

    NASA Astrophysics Data System (ADS)

    Yoshidomi, Shinya; Kimura, Shunsuke; Hasumi, Masahiko; Sameshima, Toshiyuki

    2015-11-01

    We report the increase in transmittance efficiency of the intermediate layer for multijunction solar cells caused by the indium-gallium-zinc-oxide (IGZO) layer used as the antireflection layer. Si substrates coated with a 200-nm-thick IGZO layer with a refractive index of 1.85 were prepared. The resistivity of the IGZO layer was increased from 0.0069 (as-deposited) to 0.032 ? cm by heat treatment at 350 °C for 1 h to prevent free-carrier optical absorption. Samples with the Si/IGZO/adhesive/IGZO/Si structure were fabricated. The average transmissivity for wavelengths between 1200 and 1600 nm was 49%, which was close to 55% of single-crystal silicon substrates. A high effective transmittance efficiency of 89% was experimentally achieved. The numerical calculation showed in an effective transmittance efficiency of 99% for 170-nm-thick antireflection layers with a resistivity of 0.6 ? cm and a refractive index of 2.1.

  5. Aluminium phosphide-induced leukopenia

    PubMed Central

    Ntelios, Dimitrios; Mandros, Charalampos; Potolidis, Evangelos; Fanourgiakis, Panagiotis

    2013-01-01

    Acute intoxication from the pesticide aluminium phosphide is a relatively rare, life-threatening condition in which cardiovascular decompensation is the most feared problem. We report the case of a patient exposed to aluminium phosphide-liberated phosphine gas. It resulted in the development of a gastroenteritis-like syndrome accompanied by severe reduction in white blood cell numbers as an early and prominent manifestation. By affecting important physiological processes such as mitochondrial function and reactive oxygen species homeostasis, phosphine could cause severe toxicity. After presenting the characteristics of certain leucocyte subpopulations we provide the current molecular understanding of the observed leukopenia which in part seems paradoxical. PMID:24172776

  6. Perylene Bisimide as a Promising Zinc Oxide Surface Modifier: Enhanced Interfacial Combination for Highly Efficient Inverted Polymer Solar Cells.

    PubMed

    Nian, Li; Zhang, Wenqiang; Wu, Siping; Qin, Leiqiang; Liu, Linlin; Xie, Zengqi; Wu, Hongbin; Ma, Yuguang

    2015-11-25

    We report the application of a perylene bisimide (PBI-H) as zinc oxide (ZnO) surface modifier to afford an organic-inorganic co-interlayer for highly efficient inverted organic photovoltaics (i-OPV). By thermal annealing, a N-Zn chemical bond formed between PBI-H and ZnO, inducing close organic-inorganic combination. In addition, this co-interlayer shows decreased work function and increased electron transportation and conductivity, which are benefits for the cathode to enhance charge extraction efficiency and decrease recombination losses. As a result a highly efficient i-OPV was achieved with a power conversion efficiency (PCE) of 9.43% based on this co-interlayer with PTB7:PC71BM as the active layer, which shows over 35% enhancement compared to that of the device without the PBI-H layer. Moreover, this co-interlayer was widely applicable for i-OPVs based on various material systems, such as P3HT:PC61BM and PTB7-Th:PC71BM, resulting in PCE as high as 4.78% and 10.31%, respectively. PMID:26550849

  7. Nanowire-based All Oxide Solar Cells

    SciTech Connect

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

    2008-12-07

    We present an all-oxide solar cell fabricated from vertically oriented zinc oxide nanowires and cuprous oxide nanoparticles. Our solar cell consists of vertically oriented n-type zinc oxide nanowires, surrounded by a film constructed from p-type cuprous oxide nanoparticles. Our solution-based synthesis of inexpensive and environmentally benign oxide materials in a solar cell would allow for the facile production of large-scale photovoltaic devices. We found that the solar cell performance is enhanced with the addition of an intermediate oxide insulating layer between the nanowires and the nanoparticles. This observation of the important dependence of the shunt resistance on the photovoltaic performance is widely applicable to any nanowire solar cell constructed with the nanowire array in direct contact with one electrode.

  8. Effect of resveratrol and zinc on intracellular zinc status in normal human prostate epithelial cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To evaluate the influence of resveratrol on cellular zinc status, normal human prostate epithelial (NHPrE) cells were treated with 6 levels of resveratrol (0, 0.5, 1, 2.5, 5 and 10 microM) and 4 levels of zinc [0, 4, 16, and 32 microM for zinc-deficient (ZD), zinc-normal (ZN), zinc-adequate (ZA), an...

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

    PubMed

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

    2015-03-25

    In this study, we employed polyethylenimine-doped sol-gel-processed zinc oxide composites (ZnO:PEI) as efficient electron transport layers (ETL) for facilitating electron extraction in inverted polymer solar cells. Using ultraviolet photoelectron spectroscopy, synchrotron grazing-incidence small-angle X-ray scattering and transmission electron microscopy, we observed that ZnO:PEI composite films' energy bands could be tuned considerably by varying the content of PEI up to 7 wt %-the conduction band ranged from 4.32 to 4.0 eV-and the structural order of ZnO in the ZnO:PEI thin films would be enhanced to align perpendicular to the ITO electrode, particularly at 7 wt % PEI, facilitating electron transport vertically. We then prepared two types of bulk heterojunction systems-based on poly(3-hexylthiophene) (P3HT):phenyl-C61-butryric acid methyl ester (PC61BM) and benzo[1,2-b:4,5-b?]dithiophene-thiophene-2,1,3-benzooxadiazole (PBDTTBO):phenyl-C71-butryric acid methyl ester (PC71BM)-that incorporated the ZnO:PEI composite layers. When using a composite of ZnO:PEI (93:7, w/w) as the ETL, the power conversion efficiency (PCE) of the P3HT:PC61BM (1:1, w/w) device improved to 4.6% from a value of 3.7% for the corresponding device that incorporated pristine ZnO as the ETL-a relative increase of 24%. For the PBDTTBO:PC71BM (1:2, w/w) device featuring the same amount of PEI blended in the ETL, the PCE improved to 8.7% from a value of 7.3% for the corresponding device that featured pure ZnO as its ETL-a relative increase of 20%. Accordingly, ZnO:PEI composites can be effective ETLs within organic photovoltaics. PMID:25697544

  10. Development of GaAs solar cells

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Solar cells and mesa diodes were fabricated by the implantation of zinc or beryllium ions into n-type gallium arsenide. Annealing temperatures above 750 C (zinc) or 650 C (beryllium) were found to produce 50% to 100% activation of the implanted ions. Junction depths of about 0.4 micron were produced by 600 keV zinc implants or 70 keV beryllium implants. P-layer sheet resistance was about 150 ohms for 2 x 10 to the 15th power cm/2 zinc or 1 x 10 to the 15th power cm/2 beryllium implants. This is sufficiently low for efficient solar cell fabrication. Contacting procedures were improved to yield reproducibly adherent, low resistance front and back contacts.

  11. Direct Effect of Zinc on Mitochondrial Apoptogenesis in Prostate Cells

    PubMed Central

    Feng, Pei; Li, Tie-Luo; Guan, Zhi-Xin; Franklin, Renty B.; Costello, Leslie C.

    2015-01-01

    BACKGROUND Prostate epithelial cells uniquely accumulate significantly higher levels of zinc than other mammalian cells. We previously showed that the accumulation of high intracellular zinc levels in specific prostate cells results in the induction of apoptosis and the inhibition of cell growth. The apoptotic effect is due to zinc induction of mitochondrial apoptogenesis. We now report additional studies that corroborate this effect of zinc and provide insight into the mechanism of this unique effect. METHODS The effect of exposure to physiological levels of zinc on apoptosis was determined for three human prostate cell lines (PC-3, BPH, and HPR-1). Zinc-induced apoptosis was identified by DNA fragmentation. The direct effect of zinc on isolated mitochondrial preparations from each cell line was determined. The mitochondrial release of cytochrome c was determined by Western blot. RESULTS Exposure to zinc induced apoptosis in PC-3 and BPH cells but not in HPR-1 cells. The zinc accumulation in PC-3 (4.3 ± 0.3) and BPH (2.8 ± 0.4) was higher than that in HPR-1 cells (1.8 ± 0.1). The apoptotic effect of zinc on PC-3 cells could be observed as early as 4–6 hr of zinc treatment, and this effect was not reversible. The exposure of isolated mitochondria from PC-3 and BPH cells to zinc resulted in the release of cytochrome c; but zinc had no effect on mitochondria from HPR-1 cells. CONCLUSIONS Exposure to zinc induces apoptosis in PC-3 and BPH cells, which accumulate high intracellular levels of zinc, but not in HPR-1 cells, which do not accumulate high levels of zinc. Once initiated, the induction of apoptosis is not reversed by the removal of zinc, i.e., it is an irreversible process. The apoptogenic effect is due to a direct effect of zinc on mitochondria that results in the release of cytochrome c. The cell specificity of zinc induction of apoptogenesis is dependent on the ability of the cells to accumulate high levels of intracellular zinc and on the ability of the mitochondria to respond to the direct effect of zinc. PMID:12210492

  12. Temperature-stable and optically transparent thin-film zinc oxide aerogel electrodes as model systems for 3D interpenetrating organic-inorganic heterojunction solar cells.

    PubMed

    Krumm, Michael; Pawlitzek, Fabian; Weickert, Jonas; Schmidt-Mende, Lukas; Polarz, Sebastian

    2012-12-01

    Novel, nanostructured electrode materials comprising porous ZnO films with aerogel morphology are presented. Almost any substrate including polymers, metals, or ceramics can be coated using a method that is suitable for mass production. The thin, porous films can be prepared from the wet gels via conventional drying, supercritical drying is not necessary. The filigree ZnO network is thermally very stable and exhibits sufficient electrical conductivity for advanced electronic applications. The latter was tested by realizing a highly desired architecture of organic-inorganic hybrid solar cells. After sensitizing of the ZnO with a purely organic squarine dye (SQ2), a nanostructured, interpenetrating 3D network of the inorganic semiconductor (ZnO) and organic semiconductor (P3HT) was prepared. The solar cell device was tested under illumination with AM 1.5G solar light (100 mW/cm(2)) and exhibited an energy conversion efficiency (?(eff)) of 0.69%. PMID:23194020

  13. 3. Right side of Zinc Plant, from Cell Room midpoint ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. Right side of Zinc Plant, from Cell Room midpoint to Plant Office (foreground) and #5 Roaster and Concentrate Handling (background). View is to the east. - Sullivan Electrolytic Zinc Plant, Government Gulch, Kellogg, Shoshone County, ID

  14. Solar Photovoltaic Cells.

    ERIC Educational Resources Information Center

    Mickey, Charles D.

    1981-01-01

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

  15. Morphology control of zinc regeneration for zinc-air fuel cell and battery

    NASA Astrophysics Data System (ADS)

    Wang, Keliang; Pei, Pucheng; Ma, Ze; Xu, Huachi; Li, Pengcheng; Wang, Xizhong

    2014-12-01

    Morphology control is crucial both for zinc-air batteries and for zinc-air fuel cells during zinc regeneration. Zinc dendrite should be avoided in zinc-air batteries and zinc pellets are yearned to be formed for zinc-air fuel cells. This paper is mainly to analyze the mechanism of shape change and to control the zinc morphology during charge. A numerical three-dimensional model for zinc regeneration is established with COMSOL software on the basis of ionic transport theory and electrode reaction electrochemistry, and some experiments of zinc regeneration are carried out. The deposition process is qualitatively analyzed by the kinetics Monte Carlo method to study the morphological change from the electrocrystallization point of view. Morphological evolution of deposited zinc under different conditions of direct currents and pulse currents is also investigated by simulation. The simulation shows that parametric variables of the flowing electrolyte, the surface roughness and the structure of the electrode, the charging current and mode affect morphological evolution. The uniform morphology of deposited zinc is attained at low current, pulsating current or hydrodynamic electrolyte, and granular morphology is obtained by means of an electrode of discrete columnar structure in combination with high current and flowing electrolyte.

  16. Study on the Realization of Zinc Point and the Zinc-Point Cell Comparison

    NASA Astrophysics Data System (ADS)

    Widiatmo, J. V.; Sakai, M.; Satou, K.; Yamazawa, K.; Tamba, J.; Arai, M.

    2011-01-01

    Continuing our study on aluminum, tin, and silver points, a study on the realization of the zinc point was conducted. Zinc-point cells were newly fabricated using 6N-nominal grade zinc samples, impurity elements of which were analyzed extensively based on glow-discharge mass spectrometry (GDMS). The present paper reports the temperature measurements done using the newly fabricated cells during the zinc freezing process, under which the zinc fixed point is defined, and the analysis of the freezing curve obtained. Comparisons of zinc-point temperatures realized by the newly fabricated cells (cell-to-cell comparisons) were also conducted. Zinc-point depression due to impurity elements was calculated based on the sum of individual estimates and the impurity element analysis. One of the cells evaluated was drawn out from its crucible and analyzed by GDMS at four points, namely, at around the center of the top, of the middle, of the bottom, and around the outer part of the middle area. The purpose of this cell disassembly is to see whether or not there has been some difference before and after cell fabrication, as well as difference in impurity element distribution within the ingot. From the aforementioned studies, some findings were obtained. First finding is that the homogeneity of the zinc ingot was within 30%, except for Pb, which was more concentrated in the center part. Second finding is that the cell-to-cell temperature difference changes along with the progressing solidification process. As a consequence, for an accurate cell-to-cell comparison, the locus in the freezing plateau where the comparison is done should be determined. Third finding is that the slope analysis estimates accurately the cell-to-cell comparison, and is consistent with the impurity analysis. This shows that the slope analysis gives extensive information about the effect of impurity to the zinc-point realization, especially after the cell fabrication.

  17. Zinc signals promote IL-2-dependent proliferation of T cells.

    PubMed

    Kaltenberg, Jennifer; Plum, Laura M; Ober-Blöbaum, Julia L; Hönscheid, Andrea; Rink, Lothar; Haase, Hajo

    2010-05-01

    Zinc signals, i.e. a change of the intracellular concentration of free zinc ions in response to receptor stimulation, are involved in signal transduction in several immune cells. Here, the role of zinc signals in T-cell activation by IL-2 was investigated in the murine cytotoxic T-cell line CTLL-2 and in primary human T cells. Measurements with the fluorescent dyes FluoZin-3 and Zinquin showed that zinc is released from lysosomes into the cytosol in response to stimulation of the IL-2-receptor. Activation of the ERK-pathway was blocked by chelation of free zinc with N,N,N',N'-tetrakis-2(pyridyl-methyl)ethylenediamine, whereas zinc was not required for STAT5 phosphorylation. In addition, the key signaling molecules MEK and ERK were activated in response to elevated free intracellular zinc, induced by incubation with zinc and the ionophore pyrithione. Downstream of ERK activation, ERK-specific gene expression of c-fos and IL-2-induced proliferation was found to depend on zinc. Further experiments indicated that inhibition of MEK and ERK-dephosphorylating protein phosphatases is the molecular mechanism for the influence of zinc on this pathway. In conclusion, an increase of cytoplasmic free zinc is required for IL-2-induced ERK signaling and proliferation of T cells. PMID:20201035

  18. Rechargeable zinc cell with alkaline electrolyte which inhibits shape change in zinc electrode

    DOEpatents

    Adler, T.C.; McLarnon, F.R.; Cairns, E.J.

    1994-04-12

    An improved rechargeable zinc cell is described comprising a zinc electrode and another electrode such as, for example, a nickel-containing electrode, and having an electrolyte containing KOH and a combination of KF and K[sub 2]CO[sub 3] salts which inhibits shape change in the zinc electrode, i.e., the zinc electrode exhibits low shape change, resulting in an improved capacity retention of the cell over an number of charge-discharge cycles, while still maintaining high discharge rate characteristics. 8 figures.

  19. Rechargeable zinc cell with alkaline electrolyte which inhibits shape change in zinc electrode

    DOEpatents

    Adler, Thomas C. (Berkeley, CA); McLarnon, Frank R. (Orinda, CA); Cairns, Elton J. (Walnut Creek, CA)

    1994-01-01

    An improved rechargeable zinc cell is described comprising a zinc electrode and another electrode such as, for example, a nickel-containing electrode, and having an electrolyte containing KOH and a combination of KF and K.sub.2 CO.sub.3 salts which inhibits shape change in the zinc electrode, i.e., the zinc electrode exhibits low shape change, resulting in an improved capacity retention of the cell over an number of charge-discharge cycles, while still maintaining high discharge rate characteristics.

  20. Photovoltaic solar cell

    DOEpatents

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

    2015-09-08

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

  1. The silicon/zinc oxide interface in amorphous silicon-based thin-film solar cells: Understanding an empirically optimized contact

    SciTech Connect

    Gerlach, D.; Wilks, R. G.; Wimmer, M.; Felix, R.; Gorgoi, M.; Lips, K.; Rech, B.; Wippler, D.; Mueck, A.; Meier, M.; Huepkes, J.; Lozac'h, M.; Ueda, S.; Sumiya, M.; Yoshikawa, H.; Kobayashi, K.; Baer, M.

    2013-07-08

    The electronic structure of the interface between the boron-doped oxygenated amorphous silicon 'window layer' (a-SiO{sub x}:H(B)) and aluminum-doped zinc oxide (ZnO:Al) was investigated using hard x-ray photoelectron spectroscopy and compared to that of the boron-doped microcrystalline silicon ({mu}c-Si:H(B))/ZnO:Al interface. The corresponding valence band offsets have been determined to be (-2.87 {+-} 0.27) eV and (-3.37 {+-} 0.27) eV, respectively. A lower tunnel junction barrier height at the {mu}c-Si:H(B)/ZnO:Al interface compared to that at the a-SiO{sub x}:H(B)/ZnO:Al interface is found and linked to the higher device performances in cells where a {mu}c-Si:H(B) buffer between the a-Si:H p-i-n absorber stack and the ZnO:Al contact is employed.

  2. Zinc air refuelable battery: alternative zinc fuel morphologies and cell behavior

    SciTech Connect

    Cooper, J.F.; Krueger, R.

    1997-01-01

    Multicell zinc/air batteries have been tested previously in the laboratory and as part of the propulsion system of an electric bus; cut zinc wire was used as the anode material. This battery is refueled by a hydraulic transport of 0.5-1 mm zinc particles into hoppers above each cell. We report an investigation concerning alternative zinc fuel morphologies, and energy losses associated with refueling and with overnight or prolonged standby. Three types of fuel pellets were fabricated, tested and compared with results for cut wire: spheres produced in a fluidized bed electrolysis cell; elongated particles produced by gas-atomization; and pellets produced by chopping 1 mm porous plates made of compacted zinc fines. Relative sizes of the particles and cell gap dimensions are critical. All three types transported within the cell 1553 and showed acceptable discharge characteristics, but a fluidized bed approach appears especially attractive for owner/user recovery operations.

  3. Solar cell device

    SciTech Connect

    Nishiura, M.; Haruki, H.; Miyagi, M.; Sakai, H.; Uchida, Y.

    1984-06-26

    A solar cell array is equipped with serially or parallel connected reverse polarity diodes formed simultaneously with the array. The diodes are constituted by one or more solar cells of the array which may be shaded to prevent photoelectric conversion, and which are electrically connected in reverse polarity with respect to the remaining cells.

  4. High efficiency cadmium telluride and zinc telluride based thin-film solar cells. Annual subcontract report, 1 March 1990--28 February 1992

    SciTech Connect

    Rohatgi, A.; Sudharsanan, R.; Ringel, S.A.; Chou, H.C.

    1992-10-01

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

  5. Heterojunction solar cell

    DOEpatents

    Olson, Jerry M. (Lakewood, CO)

    1994-01-01

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

  6. Heterojunction solar cell

    DOEpatents

    Olson, J.M.

    1994-08-30

    A high-efficiency single heterojunction solar cell is described wherein a thin emitter layer (preferably Ga[sub 0.52]In[sub 0.48]P) forms a heterojunction with a GaAs absorber layer. The conversion efficiency of the solar cell is at least 25.7%. The solar cell preferably includes a passivating layer between the substrate and the absorber layer. An anti-reflection coating is preferably disposed over the emitter layer. 1 fig.

  7. High-efficiency cadmium and zinc-telluride-based thin-film solar cells. Annual subcontract report, 1 March 1990--28 February 1991

    SciTech Connect

    Rohatgi, A.; Sudharsanan, R.; Ringel, S.

    1992-02-01

    This report describes research into polycrystalline CdTe solar cells grown by metal-organic chemical vapor deposition. Efficiencies of {approximately}10% were achieved using both p-i-n and p-n structures. A pre-heat treatment of CdS/SnO{sub 2}/glass substrates at 450{degrees}C in hydrogen atmosphere prior to the CdTe growth was found to be essential for high performance because this heat treatment reduces oxygen-related defects from the CdS surface. However, this treatment also resulted in a Cd-deficient CdS surface, which may in part limit the CdTe cell efficiency to 10% due to Cd vacancy-related interface defects. Preliminary model calculations suggest that removing these states can increase the cell efficiency from 10% to 13.5%. Photon absorption in the CdS film also limits the cell performance, and eliminating this loss mechanism can result in CdTe efficiencies in excess of 18%. Polycrystalline, 1.7-e, CdZnTe films were also grown for tandem-cell applications. CdZnTe/CdS cells processed using the standard CdTe cell fabrication procedure resulted in 4.4% efficiency, high series resistance, and a band-gap shift to 1.55 eV. The formation of Zn-O at and near the CdZnTe surface is the source of high contact resistance. A saturated dichromate each prior to contact deposition was found to solve the contact resistance problem. The CdCl{sub 2} treatment was identified as the cause of the observed band-gap shift due to the preferred formation of ZnCl{sub 2}. 59 refs.

  8. Redistribution of NAVSEC-1 composition on zinc anodes during silver-zinc cell cycling

    SciTech Connect

    Hammersley, V.L.; Wharton, S.P.; Winter, B.T.

    1997-12-01

    A number of elements have been used as additives to zinc electrodes in silver-zinc batteries. The purpose of these additives is to suppress hydrogen evolution and minimize shape change of the zinc electrode. Corrosion of the zinc electrode results in loss of material at the top and along the sides in preference to the bottom. Studies have been conducted on the comparison of the additives and their effect on capacity over a period of time. The present study consisted of analyzing zinc plates for the distribution of the NAVSEC-1 mixture. The mixture consists of 2% cadmium oxide and 1% lead oxide. The effectiveness of these additives to reduce hydrogen evolution and minimize shape change depends on the distribution of the components. Comparisons of virgin zinc plates with baseline and 50 cycle cell plates were made.

  9. Development and interface/surface characterization of titanium dioxide and zinc oxide electron-collection interlayer materials for organic solar cells

    NASA Astrophysics Data System (ADS)

    Ou, Kai-Lin

    My research on metal oxide electron-harvesting interlayers for organic solar cells was focused as three interrelated projects in this dissertation: i) development of a chemical vapor deposition (CVD) system for TiO 2 film; ii) an electrochemical methodology to evaluate ZnO thin film charge (hole) blocking ability; iii) the effects of plasma modifications on sol-gel ZnO and sol-gel ZnO/organic (active layer) interfaces. In i), we showed that nanoscale (12-36 nm) CVD TiO2 film deposited at 210 oC obtains properties of conformal growth, superior hole blocking ability, stoichiometric metal to oxide ratio. The introduction of CVD TiO2 film as an electron transport layer into organic solar cell significantly improves its J-V characteristics. The optimum TiO2 thickness in the OPV device applications was found to be 24 nm with a high fill factor (0.58) and power conversion efficiency (3.7%) obtained. In ii), simple electrochemical methods, i.e., cyclic voltammetry, impedance spectroscopy have been used to evaluate sol-gel derived ZnO (sg-ZnO) and sputtered ZnO (sp-ZnO) porosity and pinhole density. We showed that sg-ZnO with high surface area porous structure allows the probe molecules and poly-thiophene (P3HT) thin layer to direct contact ITO substrate, whereas sp-ZnO with dense structural property efficiently eliminates these electroactivities. This electrochemical property difference also directly reflects on the device shunt resistance (Rp), where we observed larger leakage current for the devices using sg-ZnO than that of devices using sp-ZnO. In iii), we demonstrated low power radio frequency (RF) O2 and Ar plasma treatments have significant impacts on sg-ZnO near-surface chemical compositions, which in turn influence the onset potential of sg-ZnO electron injection and its energetic alignment with electron acceptors, e.g., C60. Using UPS, we found the presence of localized mid-gap states near the Fermi-level of sg-ZnO, which induces the most favorable band bending and the largest vacuum level shift due to significant electron transfer from sg-ZnO to C60. As a result, the resultant solar cells show the best device performance. Upon the plasma treatments, the passivation effects eliminate the mid-gap state. Therefore, we observed less degree of band bending at ZnO/C60 interface and poorer device performance for the plasma treated sg-ZnO.

  10. High-efficiency solar cell and method for fabrication

    DOEpatents

    Hou, H.Q.; Reinhardt, K.C.

    1999-08-31

    A high-efficiency 3- or 4-junction solar cell is disclosed with a theoretical AM0 energy conversion efficiency of about 40%. The solar cell includes p-n junctions formed from indium gallium arsenide nitride (InGaAsN), gallium arsenide (GaAs) and indium gallium aluminum phosphide (InGaAlP) separated by n-p tunnel junctions. An optional germanium (Ge) p-n junction can be formed in the substrate upon which the other p-n junctions are grown. The bandgap energies for each p-n junction are tailored to provide substantially equal short-circuit currents for each p-n junction, thereby eliminating current bottlenecks and improving the overall energy conversion efficiency of the solar cell. Additionally, the use of an InGaAsN p-n junction overcomes super-bandgap energy losses that are present in conventional multi-junction solar cells. A method is also disclosed for fabricating the high-efficiency 3- or 4-junction solar cell by metal-organic chemical vapor deposition (MOCVD). 4 figs.

  11. High-efficiency solar cell and method for fabrication

    DOEpatents

    Hou, Hong Q. (Albuquerque, NM); Reinhardt, Kitt C. (Albuquerque, NM)

    1999-01-01

    A high-efficiency 3- or 4-junction solar cell is disclosed with a theoretical AM0 energy conversion efficiency of about 40%. The solar cell includes p-n junctions formed from indium gallium arsenide nitride (InGaAsN), gallium arsenide (GaAs) and indium gallium aluminum phosphide (InGaAlP) separated by n-p tunnel junctions. An optional germanium (Ge) p-n junction can be formed in the substrate upon which the other p-n junctions are grown. The bandgap energies for each p-n junction are tailored to provide substantially equal short-circuit currents for each p-n junction, thereby eliminating current bottlenecks and improving the overall energy conversion efficiency of the solar cell. Additionally, the use of an InGaAsN p-n junction overcomes super-bandgap energy losses that are present in conventional multi-junction solar cells. A method is also disclosed for fabricating the high-efficiency 3- or 4-junction solar cell by metal-organic chemical vapor deposition (MOCVD).

  12. Solar cell radiation handbook

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

    Solar cell theory cells are manufactured, and how they are modeled mathematically is reviewed. The interaction of energetic charged particle radiation with solar cells is discussed in detail and the concept of 1 MeV equivalent electron fluence is introduced. The space radiation environment is described and methods of calculating equivalent fluences for the space environment are developed. A computer program was written to perform the equivalent fluence calculations and a FORTRAN listing of the program is included. Finally, an extensive body of data detailing the degradation of solar cell electrical parameters as a function of 1 MeV electron fluence is presented.

  13. Characterization of Zinc Influx Transporters (ZIPs) in Pancreatic ? Cells

    PubMed Central

    Liu, Ying; Batchuluun, Battsetseg; Ho, Louisa; Zhu, Dan; Prentice, Kacey J.; Bhattacharjee, Alpana; Zhang, Ming; Pourasgari, Farzaneh; Hardy, Alexandre B.; Taylor, Kathryn M.; Gaisano, Herbert; Dai, Feihan F.; Wheeler, Michael B.

    2015-01-01

    Zinc plays an essential role in the regulation of pancreatic ? cell function, affecting important processes including insulin biosynthesis, glucose-stimulated insulin secretion, and cell viability. Mutations in the zinc efflux transport protein ZnT8 have been linked with both type 1 and type 2 diabetes, further supporting an important role for zinc in glucose homeostasis. However, very little is known about how cytosolic zinc is controlled by zinc influx transporters (ZIPs). In this study, we examined the ? cell and islet ZIP transcriptome and show consistent high expression of ZIP6 (Slc39a6) and ZIP7 (Slc39a7) genes across human and mouse islets and MIN6 ? cells. Modulation of ZIP6 and ZIP7 expression significantly altered cytosolic zinc influx in pancreatic ? cells, indicating an important role for ZIP6 and ZIP7 in regulating cellular zinc homeostasis. Functionally, this dysregulated cytosolic zinc homeostasis led to impaired insulin secretion. In parallel studies, we identified both ZIP6 and ZIP7 as potential interacting proteins with GLP-1R by a membrane yeast two-hybrid assay. Knock-down of ZIP6 but not ZIP7 in MIN6 ? cells impaired the protective effects of GLP-1 on fatty acid-induced cell apoptosis, possibly via reduced activation of the p-ERK pathway. Therefore, our data suggest that ZIP6 and ZIP7 function as two important zinc influx transporters to regulate cytosolic zinc concentrations and insulin secretion in ? cells. In particular, ZIP6 is also capable of directly interacting with GLP-1R to facilitate the protective effect of GLP-1 on ? cell survival. PMID:25969539

  14. NREL Scientists Spurred the Success of Multijunction Solar Cells (Fact Sheet)

    SciTech Connect

    Not Available

    2012-09-01

    Before 1984, many scientists believed that high-quality gallium indium phosphide (GaInP) alloys could not be grown for use as semiconductors because the alloys would separate. One researcher at the Solar Energy Research Institute (SERI) thought differently. His name was Jerry Olson, and his innovative thinking changed solar history. Olson identified a material combination that allowed the multijunction cell to flourish. It is now the workhorse that powers satellites and the catalyst for renewed interest in concentrator photovoltaic (CPV) products.

  15. Efficient water reduction with gallium phosphide nanowires

    NASA Astrophysics Data System (ADS)

    Standing, Anthony; Assali, Simone; Gao, Lu; Verheijen, Marcel A.; van Dam, Dick; Cui, Yingchao; Notten, Peter H. L.; Haverkort, Jos E. M.; Bakkers, Erik P. A. M.

    2015-07-01

    Photoelectrochemical hydrogen production from solar energy and water offers a clean and sustainable fuel option for the future. Planar III/V material systems have shown the highest efficiencies, but are expensive. By moving to the nanowire regime the demand on material quantity is reduced, and new materials can be uncovered, such as wurtzite gallium phosphide, featuring a direct bandgap. This is one of the few materials combining large solar light absorption and (close to) ideal band-edge positions for full water splitting. Here we report the photoelectrochemical reduction of water, on a p-type wurtzite gallium phosphide nanowire photocathode. By modifying geometry to reduce electrical resistance and enhance optical absorption, and modifying the surface with a multistep platinum deposition, high current densities and open circuit potentials were achieved. Our results demonstrate the capabilities of this material, even when used in such low quantities, as in nanowires.

  16. Efficient water reduction with gallium phosphide nanowires.

    PubMed

    Standing, Anthony; Assali, Simone; Gao, Lu; Verheijen, Marcel A; van Dam, Dick; Cui, Yingchao; Notten, Peter H L; Haverkort, Jos E M; Bakkers, Erik P A M

    2015-01-01

    Photoelectrochemical hydrogen production from solar energy and water offers a clean and sustainable fuel option for the future. Planar III/V material systems have shown the highest efficiencies, but are expensive. By moving to the nanowire regime the demand on material quantity is reduced, and new materials can be uncovered, such as wurtzite gallium phosphide, featuring a direct bandgap. This is one of the few materials combining large solar light absorption and (close to) ideal band-edge positions for full water splitting. Here we report the photoelectrochemical reduction of water, on a p-type wurtzite gallium phosphide nanowire photocathode. By modifying geometry to reduce electrical resistance and enhance optical absorption, and modifying the surface with a multistep platinum deposition, high current densities and open circuit potentials were achieved. Our results demonstrate the capabilities of this material, even when used in such low quantities, as in nanowires. PMID:26183949

  17. Efficient water reduction with gallium phosphide nanowires

    PubMed Central

    Standing, Anthony; Assali, Simone; Gao, Lu; Verheijen, Marcel A.; van Dam, Dick; Cui, Yingchao; Notten, Peter H. L.; Haverkort, Jos E. M.; Bakkers, Erik P. A. M.

    2015-01-01

    Photoelectrochemical hydrogen production from solar energy and water offers a clean and sustainable fuel option for the future. Planar III/V material systems have shown the highest efficiencies, but are expensive. By moving to the nanowire regime the demand on material quantity is reduced, and new materials can be uncovered, such as wurtzite gallium phosphide, featuring a direct bandgap. This is one of the few materials combining large solar light absorption and (close to) ideal band-edge positions for full water splitting. Here we report the photoelectrochemical reduction of water, on a p-type wurtzite gallium phosphide nanowire photocathode. By modifying geometry to reduce electrical resistance and enhance optical absorption, and modifying the surface with a multistep platinum deposition, high current densities and open circuit potentials were achieved. Our results demonstrate the capabilities of this material, even when used in such low quantities, as in nanowires. PMID:26183949

  18. Solar cell radiation handbook

    NASA Technical Reports Server (NTRS)

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

    1982-01-01

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

  19. Dye Sensitized Solar Cells

    PubMed Central

    Wei, Di

    2010-01-01

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

  20. Lateral superlattice solar cells

    SciTech Connect

    Mascarenhas, A.; Zhang, Y.; Millunchick, J.M.; Twesten, R.D.; Jones, E.D.

    1997-10-01

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

  1. ZINC TRANSPORTER 8 (ZNT8) AND BETA CELL FUNCTION

    PubMed Central

    Davidson, Howard W.; Wenzlau, Janet M.; O’Brien, Richard M.

    2014-01-01

    Human pancreatic ? cells have exceptionally high zinc content. In ? cells the highest zinc concentration is in insulin secretory granules, from which it is co-secreted with the hormone. Uptake of zinc into secretory granules is mainly mediated by zinc transporter 8 (ZnT8), the product of the SLC30A8 gene. The minor alleles of several single nucleotide polymorphisms (SNPs) in SLC30A8 are associated with decreased risk of type 2 diabetes (T2D), but the precise mechanisms underlying the protective effects remain uncertain. In this article we review current knowledge of the role of ZnT8 in maintaining zinc homeostasis in ? cells, its role in glucose metabolism based on knockout mouse studies, and current theories regarding the link between ZnT8 function and T2D. PMID:24751356

  2. Thin boron phosphide coating as a corrosion-resistant layer

    DOEpatents

    Not Available

    1982-08-25

    A surface prone to corrosion in corrosive environments is rendered anticorrosive by CVD growing a thin continuous film, e.g., having no detectable pinholes, thereon, of boron phosphide. In one embodiment, the film is semiconductive. In another aspect, the invention is an improved photoanode, and/or photoelectrochemical cell with a photoanode having a thin film of boron phosphide thereon rendering it anticorrosive, and providing it with unexpectedly improved photoresponsive properties.

  3. Spray deposited copper zinc tin sulphide (Cu2ZnSnS4) film as a counter electrode in dye sensitized solar cells.

    PubMed

    Swami, Sanjay Kumar; Chaturvedi, Neha; Kumar, Anuj; Chander, Nikhil; Dutta, Viresh; Kumar, D Kishore; Ivaturi, A; Senthilarasu, S; Upadhyaya, Hari M

    2014-11-21

    Stoichiometric thin films of Cu2ZnSnS4 (CZTS) were deposited by the spray technique on a FTO coated glass substrate, with post-annealing in a H2S environment to improve the film properties. CZTS films were used as a counter electrode (CE) in Dye-Sensitized Solar Cells (DSCs) with N719 dye and an iodine electrolyte. The DSC of 0.25 cm(2) area using a CE of CZTS film annealed in a H2S environment under AM 1.5G illumination (100 mW cm(-2)) exhibited a short circuit current density (JSC) = 18.63 mA cm(-2), an open circuit voltage (VOC) = 0.65 V and a fill factor (FF) = 0.53, resulting in an overall power conversion efficiency (PCE) = 6.4%. While the DSC using as deposited CZTS film as a CE showed the PCE = 3.7% with JSC = 13.38 mA cm(-2), VOC = 0.57 V and FF = 0.48. Thus, the spray deposited CZTS films can play an important role as a CE in the large area DSC fabrication. PMID:25286339

  4. A novel triple-layer zinc oxide/carbon nanotube architecture for dye-sensitized solar cells with excellent power conversion efficiency

    NASA Astrophysics Data System (ADS)

    Hu, Jing; Xie, Yahong; Bai, Te; Zhang, Chunyang; Wang, Jide

    2015-07-01

    A novel triple-layer photoanode architecture, composed of ZnO and ZnO/CNT nanostructure semiconductor films for dye-sensitized solar cell with excellent power conversion efficiency is fabricated by a simple strategy. A convenient and effective method is applied to disperse the multiwalled carbon nanotube (MWCNT). The structure, morphology and light absorption of the novel hybrid photoanode are characterized by X-ray diffraction, scanning electron microscopy, and UV-vis absorption spectroscopy analyze. Results indicate that the ZnO has a typical wurtzite structure and the MWCNTs are homogeneously dispersed in ZnO. Current-voltage curves demonstrate CNT-0.5 with 0.05wt% of carbon nanotube (CNT) is the most suitable in improving the performance of DSSCs, and the power conversion efficiency of ZnO/CNT-0.5-0.05wt% is 6.25%, which is 35.57% higher than those without CNTs (4.61%). Finally, electrochemical impedance spectra confirms that the abundant dyes absorption by the ZnO layer and large numbers of direct pathway for electron transport provided by the MWCNTs are attributed to the high efficiency of this new DSSC. This result is remarkable and provides a novel triple-layer ZnO/CNT architecture in improving the performance of DSSCs.

  5. Photoelectrochemical Solar Cells.

    ERIC Educational Resources Information Center

    McDevitt, John T.

    1984-01-01

    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…

  6. Screening of solar cells

    SciTech Connect

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

    1993-07-01

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

  7. Screening of solar cells

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

  8. Aluminium phosphide poisoning.

    PubMed

    Bogle, R G; Theron, P; Brooks, P; Dargan, P I; Redhead, J

    2006-01-01

    We describe a lethal poisoning in a healthy woman caused by deliberate ingestion of aluminium phosphide (AlP), a pesticide used to kill rodents and insects. Toxicity of AlP and review of cases reported to the National Poisons Information Service (London) 1997-2003 are discussed. PMID:16373788

  9. Nanocrystal Solar Cells

    SciTech Connect

    Gur, Ilan

    2006-12-15

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

  10. Photovoltaic solar cell

    SciTech Connect

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

    2013-11-26

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

  11. Photovoltaic solar cell

    DOEpatents

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

    2014-05-20

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

  12. Solar cell array interconnects

    DOEpatents

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

    1995-11-14

    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.

  13. Solar cell array interconnects

    DOEpatents

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

    1995-01-01

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

  14. Lightweight solar cell

    SciTech Connect

    Hotaling, S.P.

    1993-06-22

    A lightweight solar cell is described comprising: (a) an LD aerogel substrate having a density of between 10-1,000 mg/cc, the surface of the substrate being polished (b) a dielectric planarization layer being applied to the polished surface, and (c) at least one layer of PV material deposited thereon. The solar cell having a plurality of PV layers deposited on the planarization layer.

  15. Thin silicon solar cells

    SciTech Connect

    Hall, R.B.; Bacon, C.; DiReda, V.; Ford, D.H.; Ingram, A.E.; Cotter, J.; Hughes-Lampros, T.; Rand, J.A.; Ruffins, T.R.; Barnett, A.M.

    1992-12-01

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

  16. Rechargeable zinc cell with alkaline electrolyte which inhibits shape change in zinc electrode

    DOEpatents

    Adler, Thomas C. (Berkeley, CA); McLarnon, Frank R. (Orinda, CA); Cairns, Elton J. (Walnut Creek, CA)

    1995-01-01

    An improved rechargeable zinc cell is described comprising a zinc electrode and another electrode such as, for example, a nickel-containing electrode, and having an electrolyte containing one or more hydroxides having the formula M(OH), one or more fluorides having the formula MF, and one or more carbonates having the formula M.sub.2 CO.sub.3, where M is a metal selected from the group consisting of alkali metals. The electrolyte inhibits shape change in the zinc electrode, i.e., the zinc electrode exhibits low shape change, resulting in an improved capacity retention of the cell over an number of charge-discharge cycles, while still maintaining high discharge rate characteristics.

  17. Integrated solar cell and battery

    SciTech Connect

    Little, R.G.

    1988-04-26

    An integrated solar cell and battery is described comprising: (a) a substrate; and (b) a solar cell and a thin film battery including a solid electrolyte, deposited by thin film deposition techniques on the substrate; (c) the substrate and the solar cell together comprising a bulk type solar cell.

  18. Welded solar cell interconnection

    NASA Technical Reports Server (NTRS)

    Stofel, E. J.; Browne, E. R.; Meese, R. A.; Vendura, G. J.

    1982-01-01

    The efficiency of the welding of solar-cell interconnects is compared with the efficiency of soldering such interconnects, and the cases in which welding may be superior are examined. Emphasis is placed on ultrasonic welding; attention is given to the solar-cell welding machine, the application of the welding process to different solar-cell configurations, producibility, and long-life performance of welded interconnects. Much of the present work has been directed toward providing increased confidence in the reliability of welding using conditions approximating those that would occur with large-scale array production. It is concluded that there is as yet insufficient data to determine which of three methods (soldering, parallel gap welding, and ultrasonic welding) provides the longest-duration solar panel life.

  19. Development and fabrication of large vented nickel-zinc cells

    NASA Technical Reports Server (NTRS)

    Donnel, C. P., III

    1975-01-01

    A preliminary cell design for a 300AH vented nickel-zinc cell was established based on volume requirements and cell component materials selected by NASA Lewis Research Center. A 100AH cell configuration was derived from the 300AH cell design utilizing the same size electrodes, separators, and cell terminal hardware. The first cells fabricated were four groups of three cells each in the 100AH size. These 100AH experimental nickel-zinc cells had as common components the nickel positive electrodes (GFM), flexible inorganic separator (GFM) bags on the negative electrodes, pressed powder zinc oxide electrodes, and cell containers with hardware. The variations introduced were four differing electrolyte absorber (interseparator) systems used to encase the nickel positive electrodes of each cell group. The four groups of 100AH experimental vented nickel-zinc cells were tested to determine, based on cell performance, the best two interseparator systems. Using the two interseparator systems, two groups of experimental 300AH cells were fabricated. Each group of three cells differed only in the interseparator material used. The six cells were filled, formed and tested to evaluate the interseparator materials and investigate the performance characteristics of the 300AH cell configuration and its components.

  20. ZINC

    EPA Science Inventory

    This report summarizes the available information on zinc as it relates to its effects on man and his environment. Zinc is found in most soils, but some areas are deficient in it. Metallurgic operations contribute to zinc contamination in air, water and soil. Trace amounts of zinc...

  1. Fabrication and testing of sealed silver-zinc cells

    NASA Technical Reports Server (NTRS)

    Donnel, C. P., III

    1976-01-01

    A number of Type HS40-7 sealed silver-zinc cells and experimental 40AH sealed silver-zinc cells were fabricated. Cells of each experimental group contained one variation from the standard configuration (HS40-7) cell. Cells from each of five experimental cell groups and cells of the standard configuration were tested to characterize voltage and capacity performance at various discharge rates. The test cells were then subjected to 100 percent DOD Cycle Life Testing at 22 C. Results indicate that material and/or process variations are available which will improve both performance and cycle life of the existing 40 ampere-hour sealed silver-zinc cell configurations. The average cycle life to 50 percent loss of nominal capacity in cells from two (2) of the experimental groups was 150 - 165 cycles. A series of 12 ampere-hour cells was fabricated and tested as part of a program to incorporate the 40AH sealed silver-zinc cell fabrication technology into a cell of smaller size. Base-line configuration cells and experimental variations were produced using the HS40-7 cell fabrication and processing methods adapted to the smaller cell size.

  2. Parameterization of solar cells

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  3. Broad spectrum solar cell

    DOEpatents

    Walukiewicz, Wladyslaw (Kensington, CA); Yu, Kin Man (Lafayette, CA); Wu, Junqiao (Richmond, CA); Schaff, William J. (Ithaca, NY)

    2007-05-15

    An alloy having a large band gap range is used in a multijunction solar cell to enhance utilization of the solar energy spectrum. In one embodiment, the alloy is In.sub.1-xGa.sub.xN having an energy bandgap range of approximately 0.7 eV to 3.4 eV, providing a good match to the solar energy spectrum. Multiple junctions having different bandgaps are stacked to form a solar cell. Each junction may have different bandgaps (realized by varying the alloy composition), and therefore be responsive to different parts of the spectrum. The junctions are stacked in such a manner that some bands of light pass through upper junctions to lower junctions that are responsive to such bands.

  4. Ingestion of gallium phosphide nanowires has no adverse effect on Drosophila tissue function

    NASA Astrophysics Data System (ADS)

    Adolfsson, Karl; Schneider, Martina; Hammarin, Greger; Häcker, Udo; Prinz, Christelle N.

    2013-07-01

    Engineered nanoparticles have been under increasing scrutiny in recent years. High aspect ratio nanoparticles such as carbon nanotubes and nanowires have raised safety concerns due to their geometrical similarity to asbestos fibers. III-V epitaxial semiconductor nanowires are expected to be utilized in devices such as LEDs and solar cells and will thus be available to the public. In addition, clean-room staff fabricating and characterizing the nanowires are at risk of exposure, emphasizing the importance of investigating their possible toxicity. Here we investigated the effects of gallium phosphide nanowires on the fruit fly Drosophila melanogaster. Drosophila larvae and/or adults were exposed to gallium phosphide nanowires by ingestion with food. The toxicity and tissue interaction of the nanowires was evaluated by investigating tissue distribution, activation of immune response, genome-wide gene expression, life span, fecundity and somatic mutation rates. Our results show that gallium phosphide nanowires applied through the diet are not taken up into Drosophila tissues, do not elicit a measurable immune response or changes in genome-wide gene expression and do not significantly affect life span or somatic mutation rate.

  5. Welded solar cell interconnection

    SciTech Connect

    Stofel, E.J.; Browne, E.R.; Meese, R.A.; Vendura, G.J.

    1982-09-01

    The welding of solar cell interconnects has received increased attention in recent years. Welding is used routinely in Europe and is being investigated seriously by several solar array fabricators in the United States. Most of this welding has been made using parallel gap resistive heating. Hughes Aircraft Company has chosen to investigate ultrasonic welding as an alternate bonding method. The results of this work and the manner in which ultrasonic welding differs from parallel gap welding or soldering is herein summarized.

  6. Making Ultrathin Solar Cells

    NASA Technical Reports Server (NTRS)

    Cogan, George W.; Christel, Lee A.; Merchant, J. Thomas; Gibbons, James F.

    1991-01-01

    Process produces extremely thin silicon solar cells - only 50 micrometers or less in thickness. Electrons and holes have less opportunity to recombine before collected at cell surfaces. Efficiency higher and because volume of silicon small, less chance of radiation damage in new cells. Initial steps carried out at normal thickness to reduce breakage and avoid extra cost of special handling. Cells then thinned mechanically and chemically. Final cell includes reflective layer on back surface. Layer bounces unabsorbed light back into bulk silicon so it absorbs and produces useful electrical output.

  7. III-V solar cells and doping processes

    SciTech Connect

    Fraas, L.M.; Sundaram, V.S.; Avery, J.E.; Gruenhaum, P.E.; Malocsay, E.

    1993-06-08

    A tandem solar cell concentrator module is described comprising: (a) a concentrator lens for focusing incident solar radiation; (b) a tandem solar cell substantially at the focus of the lens, the cell including: (i) an upper AlGaAs/GaAs primary cell having: (1) an AlGaAs window covering a photoactive region of a generally n-type GaAs wafer, and (2) a zinc-diffused, p-type emitter region having a concentration of zinc of between about 10[sup 18]-10[sup 19] atoms/cm[sup 3]; and (ii) a lower GaSb booster cell positioned to receive solar radiation that passes through the primary cell, the booster cell including grid lines on the upper surface for collecting current produced in the booster cell by incident radiation, a heavy concentration of zinc under the rid lines to provide low ohmic contact resistance, and a light concentration of zinc between the grid lines, the light concentration being effective to preserve the minority carrier lifetime in the booster cell to increase the short circuit current; wherein the booster cell includes texture etching to increase the conversion efficiency and to reduce reflection losses, the etching patterning the booster cell in the regions between the grid lines, and includes a backside metallization comprising layers of indium tin oxide, titanium tungsten nitride, and silver overlying one another, the indium tin oxide adjacent the GaSb and the silver at the exposed surface; (c) a heat spreader attached to both the primary cell and booster cell for holding the two in proper spaced relationship and for conveying excess heat away from either to a heat sink; and (d) current collection means connected to the primary cell and booster cell for collecting current generated in both when solar radiation is focused on the module.

  8. Solar cell radiation handbook

    NASA Technical Reports Server (NTRS)

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

    1973-01-01

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

  9. Flexible Solar Cells

    NASA Technical Reports Server (NTRS)

    1994-01-01

    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 Film Technologies under NASA and DOE grants, the modules are used as electrical supply for advertising displays, battery rechargers for recreational vehicles, and to power model airplanes. The company is planning other applications both in consumer goods and as a power source in underdeveloped countries.

  10. Monolithic tandem solar cell

    DOEpatents

    Wanlass, Mark W. (Golden, CO)

    1991-01-01

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

  11. Surface passivation of InP solar cells with InAlAs layers

    NASA Technical Reports Server (NTRS)

    Jain, Raj K.; Flood, Dennis J.; Landis, Geoffrey A.

    1993-01-01

    The efficiency of indium phosphide solar cells is limited by high values of surface recombination. The effect of a lattice-matched In(0.52)Al(0.48)As window layer material for InP solar cells, using the numerical code PC-1D is investigated. It was found that the use of InAlAs layer significantly enhances the p(+)n cell efficiency, while no appreciable improvement is seen for n(+)p cells. The conduction band energy discontinuity at the heterojunction helps in improving the surface recombination. An optimally designed InP cell efficiency improves from 15.4 percent to 23 percent AMO for a 10 nm thick InAlAs layer. The efficiency improvement reduces with increase in InAlAs layer thickness, due to light absorption in the window layer.

  12. Zinc

    MedlinePLUS

    ... very small amounts of zinc are necessary for human health. Zinc is used for treatment and prevention ... for the proper growth and maintenance of the human body. It is found in several systems and ...

  13. Interleukin-1 stimulates zinc uptake by human thymic epithelial cells

    SciTech Connect

    Coto, J.A.; Hadden, J.W. )

    1991-03-15

    Thymic epithelial cells (TEC) are known to secrete peptides which influence the differentiation and maturation of T-lymphocytes. These peptides include the thymic hormones thymulin, thymosin-{alpha}1, and thymopoietin. The biological activity of thymulin is dependent on the presence of zinc in an equimolar ratio. The authors have shown that both interleukin-1{alpha}(IL-1{alpha}) and interleukin-1{beta}(IL-1{beta}), which stimulate proliferation of TEC, stimulate the uptake of Zn-65 in-vitro independent of this proliferation. Mitomycin-C was used to inhibit the proliferation of TEC. Two other stimulators of proliferation of TEC, bovine pituitary extract (BPE) and epidermal growth factor (EGF), did not stimulate zinc uptake by the TEC independent of proliferation. They have also shown, utilizing in-situ hybridization, that IL-1 and zinc induce metallothionein(MT) mRNA expression in human thymic epithelial cells. The exact role of metallothionein is not clear, but it is thought to be involved in regulation of trace metal metabolism, especially in maintenance of zinc homeostasis. Their current hypothesis is that IL-1 stimulates uptake of zinc into the TEC, followed by its complexing with metallothionein. Zinc is then thought to be transferred from metallothionein to thymulin. Immunostaining, utilizing an antithymulin antibody and a fluoresceinated goat anti-rabbit second antibody, confirms the presence of thymulin in TEC and its dependence on zinc. Upon stimulation, thymulin is then secreted. Known stimulants for thymulin include progesterone, dexamethasone, estradiol, testosterone, and prolactin. None of these secretagogues increase zinc uptake, suggesting the priming of the zinc-thymulin complex is unrelated to the regulation of its secretion.

  14. Flexible solar cells.

    PubMed

    Pagliaro, Mario; Ciriminna, Rosaria; Palmisano, Giovanni

    2008-01-01

    Thin-film flexible photovoltaics are paving the way to low-cost electricity. Organic, inorganic and organic-inorganic solar cells are deposited over flexible substrates by high-throughput (often roll-to-roll printing) technologies to afford lightweight, economic solar modules that can be integrated into, not installed on, various surfaces. Current conversion efficiencies under standard conditions are in the 3-15 % range, but in real applications the overall productivity is high. These new photovoltaic technologies are ready to provide cheap, clean electricity to the 2 billion people who lack access to the grid as well as to energy-eager companies and families in the developed world facing the increasing costs of electricity generated using fossil fuel resources. This Review focuses on recent achievements in the area of flexible solar cells, highlights the principles behind the main technologies, and discusses future challenges in this area. PMID:18979493

  15. NASA Facts, Solar Cells.

    ERIC Educational Resources Information Center

    National Aeronautics and Space Administration, Washington, DC.

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

  16. Framework to predict optimal buffer layer pairing for thin film solar cell absorbers: A case study for tin sulfide/zinc oxysulfide

    NASA Astrophysics Data System (ADS)

    Mangan, Niall M.; Brandt, Riley E.; Steinmann, Vera; Jaramillo, R.; Yang, Chuanxi; Poindexter, Jeremy R.; Chakraborty, Rupak; Park, Helen Hejin; Zhao, Xizhu; Gordon, Roy G.; Buonassisi, Tonio

    2015-09-01

    An outstanding challenge in the development of novel functional materials for optoelectronic devices is identifying suitable charge-carrier contact layers. Herein, we simulate the photovoltaic device performance of various n-type contact material pairings with tin(II) sulfide (SnS), a p-type absorber. The performance of the contacting material, and resulting device efficiency, depend most strongly on two variables: conduction band offset between absorber and contact layer, and doping concentration within the contact layer. By generating a 2D contour plot of device efficiency as a function of these two variables, we create a performance-space plot for contacting layers on a given absorber material. For a simulated high-lifetime SnS absorber, this 2D performance-space illustrates two maxima, one local and one global. The local maximum occurs over a wide range of contact-layer doping concentrations (below 1016 cm-3), but only a narrow range of conduction band offsets (0 to -0.1 eV), and is highly sensitive to interface recombination. This first maximum is ideal for early-stage absorber research because it is more robust to low bulk-minority-carrier lifetime and pinholes (shunts), enabling device efficiencies approaching half the Shockley-Queisser limit, greater than 16%. The global maximum is achieved with contact-layer doping concentrations greater than 1018 cm-3, but for a wider range of band offsets (-0.1 to 0.2 eV), and is insensitive to interface recombination. This second maximum is ideal for high-quality films because it is more robust to interface recombination, enabling device efficiencies approaching the Shockley-Queisser limit, greater than 20%. Band offset measurements using X-ray photoelectron spectroscopy and carrier concentration approximated from resistivity measurements are used to characterize the zinc oxysulfide contacting layers in recent record-efficiency SnS devices. Simulations representative of these present-day devices suggest that record efficiency SnS devices are optimized for the second local maximum, due to low absorber lifetime and relatively well passivated interfaces. By employing contact layers with higher carrier concentrations and lower electron affinities, a higher efficiency ceiling can be enabled.

  17. Solar cells for solar power satellites

    NASA Technical Reports Server (NTRS)

    Oman, H.

    1978-01-01

    The concept of a solar-cell array for a solar power satellite is developed to permit evaluation of its economic feasibility for generating power for delivery to public utilities on earth. Gallium arsenide solar cells were considered but it could not be assured that the world gallium resources could support constructions of two solar power satellites per year. Therefore, for preliminary design an array blanket made from 5 by 10 cm silicon solar cells, 50 microns thick, and electrostatically bonded between borosilicate glass sheets was adopted. In annealing experiments, a radiated 50 microns thick cell was restored to its initial performance in a 500 C. Solar-cell efficiency effects significantly the solar power satellite mass, which varies from 90,000 metric tons for 20 percent cells to 120,000 metric tons for 12 percent cells. The anticipated cost of delivered power, based on 1977 dollars, varies from 4 cents per kWh with 18 percent cells, to 5 cents per kWh for 12 percent efficient cells.

  18. Zinc oxyfluoride transparent conductor

    DOEpatents

    Gordon, Roy G. (Cambridge, MA)

    1991-02-05

    Transparent, electrically conductive and infrared-reflective films of zinc oxyfluoride are produced by chemical vapor deposition from vapor mixtures of zinc, oxygen and fluorine-containing compounds. The substitution of fluorine for some of the oxygen in zinc oxide results in dramatic increases in the electrical conductivity. For example, diethyl zinc, ethyl alcohol and hexafluoropropene vapors are reacted over a glass surface at 400.degree. C. to form a visibly transparent, electrically conductive, infrared reflective and ultraviolet absorptive film of zinc oxyfluoride. Such films are useful in liquid crystal display devices, solar cells, electrochromic absorbers and reflectors, energy-conserving heat mirrors, and antistatic coatings.

  19. Modeling of high efficiency solar cells under laser pulse for power beaming applications

    NASA Technical Reports Server (NTRS)

    Jain, Raj K.; Landis, Geoffrey A.

    1994-01-01

    Solar cells have been used to convert sunlight to electrical energy for many years and also offer great potential for non-solar energy conversion applications. Their greatly improved performance under monochromatic light compared to sunlight, makes them suitable as photovoltaic (PV) receivers in laser power beaming applications. Laser beamed power to a PV array receiver could provide power to satellites, an orbital transfer vehicle, or a lunar base. Gallium arsenide (GaAs) and indium phosphide (InP) solar cells have calculated efficiencies of more than 50 percent under continuous illumination at the optimum wavelength. Currently high power free-electron lasers are being developed which operate in pulsed conditions. Understanding cell behavior under a laser pulse is important in the selection of the solar cell material and the laser. An experiment by NAsA lewis and JPL at the AVLIS laser facility in Livermore, CA presented experimental data on cell performance under pulsed laser illumination. Reference 5 contains an overview of technical issues concerning the use of solar cells for laser power conversion, written before the experiments were performed. As the experimental results showed, the actual effects of pulsed operation are more complicated. Reference 6 discusses simulations of the output of GaAs concentrator solar cells under pulsed laser illumination. The present paper continues this work, and compares the output of Si and GaAs solar cells.

  20. High efficiency solar cell structure

    SciTech Connect

    Green, M.A.; Blakers, A.W.

    1983-09-13

    The invention relates to a new-type of solar cell structure, and to a method of manufacturing same. The solar cell is designated as an MINP cell (Metal-Insulator-NP junction solar cell). Essentially, the MINP solar cell is an extremely shallow N-P junction cell with a MIS (Metal-Insulator-Semiconductor) type contact made to the top of the cell. Although combining features of the two technologies, no more processing steps are required than for a conventional P-N junction cell. The advantage of the MINP structure is its substantially improved efficiency.

  1. Transient fluctuations of intracellular zinc ions in cell proliferation

    SciTech Connect

    Li, Yuan; Maret, Wolfgang; Department of Anesthesiology, The University of Texas Medical Branch, Galveston, TX 77555

    2009-08-15

    Zinc is essential for cell proliferation, differentiation, and viability. When zinc becomes limited for cultured cells, DNA synthesis ceases and the cell cycle is arrested. The molecular mechanisms of actions of zinc are believed to involve changes in the availability of zinc(II) ions (Zn{sup 2+}). By employing a fluorescent Zn{sup 2+} probe, FluoZin-3 acetoxymethyl ester, intracellular Zn{sup 2+} concentrations were measured in undifferentiated and in nerve growth factor (NGF)-differentiated rat pheochromocytoma (PC12) cells. Intracellular Zn{sup 2+} concentrations are pico- to nanomolar in PC12 cells and are higher in the differentiated than in the undifferentiated cells. When following cellular Zn{sup 2+} concentrations for 48 h after the removal of serum, a condition that is known to cause cell cycle arrest, Zn{sup 2+} concentrations decrease after 30 min but, remarkably, increase after 1 h, and then decrease again to about one half of the initial concentration. Cell proliferation, measured by an MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay, decreases after both serum starvation and zinc chelation. Two peaks of Zn{sup 2+} concentrations occur within one cell cycle: one early in the G1 phase and the other in the late G1/S phase. Thus, fluctuations of intracellular Zn{sup 2+} concentrations and established modulation of phosphorylation signaling, via an inhibition of protein tyrosine phosphatases at commensurately low Zn{sup 2+} concentrations, suggest a role for Zn{sup 2+} in the control of the cell cycle. Interventions targeted at these picomolar Zn{sup 2+} fluctuations may be a way of controlling cell growth in hyperplasia, neoplasia, and diseases associated with aberrant differentiation.

  2. Gallium phosphide energy converters

    NASA Technical Reports Server (NTRS)

    Sims, P. E.; DiNetta, Louis C.; DuganCavanagh, K.; Goetz, M. A.

    1996-01-01

    Betavoltaic power supplies based on gallium phosphide can supply long term low-level power with high reliability. Results are presented for GaP devices powered by Ni-63 and tritiarated phosphors. Leakage currents as low as 1.2 x 10(exp -17) A/cm(exp 2) have been measured and the temperature dependence of the reverse saturation current is found to have ideal behavior. A small demonstration system has been assembled that generates and stores enough electricity to light up an LED.

  3. Thermophotovoltaic Cells on Zinc Diffused Polycrystalline GaSb

    SciTech Connect

    Sulima, O.V.; Bett, A.W.; Dutta, P.S.; Ehsani, H.; Gutmann, R.J.

    2000-05-01

    For the first time, it has been demonstrated that thermophotovoltaic cells made of polycrystalline GaSb with small grain sizes (down to 100 x 100 {micro}m) have similar characteristics to the best Zinc diffused single crystal GaSb cells with identified device parameters. The grain boundaries in polycrystalline GaSb do not degrade TPV cell parameters, indicating that such material can be used for high-efficiency thermophotovoltaic cells.

  4. EE580 Solar Cells Todd J. Kaiser

    E-print Network

    Kaiser, Todd J.

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

  5. Nighttime solar cell

    SciTech Connect

    Parise, R.J.

    1998-07-01

    Currently photovoltaic (PV) cells convert solar energy into electrical energy at an efficiency of about 18%, with the maximum conversion rate taking place around noon on a cloudless day. In many applications, the PV cells are utilized to recharge a stand-by battery pack that provides electrical energy at night or on cloudy days. Increasing the utilization of the panel array area by producing electrical power at night will reduce the amount of required electrical energy storage for a given array size and increase system reliability. Thermoelectric generators (TEG) are solid state devices that convert thermal energy into electrical energy. Using the nighttime sky, or deep space, with an effective temperature of 3.5 K as a cold sink, the TEG presented here can produce electrical power at night. The hot junction is supplied energy by the ambient air temperature or some other warm temperature source. The cold junction of the TEG is insulated from the surroundings by a vacuum cell, improving its overall effectiveness. Combining the TEG with the PV cell, a unique solid state device is developed that converts electromagnetic radiant energy into usable electrical energy. The thermoelectric-photovoltaic (TEPV) cell, or the Nighttime Solar Cell, is a direct energy conversion device that produces electrical energy both at night and during the day.

  6. DOI: 10.1002/adma.200602927 Hierarchically Structured ZnO Film for Dye-Sensitized Solar Cells

    E-print Network

    Cao, Guozhong

    DOI: 10.1002/adma.200602927 Hierarchically Structured ZnO Film for Dye-Sensitized Solar Cells* The interest in dye-sensitized solar cells has increased due to reduced energy sources and higher energy, zinc oxide (ZnO) has recently been explored as an alternative material in dye-sensitized solar cells

  7. Effect of soluble zinc on differentiation of osteoprogenitor cells

    PubMed Central

    Popp, Jenni R.; Love, Brian J.; Goldstein, Aaron S.

    2011-01-01

    Amorphous calcium phosphates (ACPs) are attractive fillers for osseous defects and are stabilized through the incorporation of transition metals such as zirconium and zinc. As ACP converts in solution to hydroxyapatite (HAP) in a manner marked by a transient release of calcium and phosphate ions, it is capable of stimulating osteoblastic differentiation. Zinc is known to retard ACP conversion to HAP, and—when incorporated into ceramic biomaterials—has been shown to stimulate osteoblastic differentiation. Because zinc deficiency in vivo is marked by skeletal defects, we postulated that zinc ions released from ACP and other minerals could stimulate proliferation and osteoblastic differentiation of progenitor cells. To test this hypothesis, rat bone marrow stromal cells were cultured in osteogenic medium containing basal (3 × 10?6 M) or supplemented Zn2+ concentrations (1 × 10?5 and 4 × 10?5 M) for up to 3 weeks. No significant effects of zinc concentration on cell number, alkaline phosphatase activity, total protein content, collagen synthesis, or matrix mineralization were found. PMID:17377969

  8. Novel chlorophyll solar cell

    SciTech Connect

    Ludlow, J.C.

    1981-01-01

    A novel solar battery is being developed which uses chlorophyll a for the generation of a voltage. The battery consists of platinum foil electrode, onto which a mixture of chlorophyll a and lipoic acid is deposited, and a platinum current collector. With such a device, voltages greater than 0.35 volts can reproducibly generated. The dependence of the output of the cell as a function of chlorophyll levels and light intensity has been determined. 9 refs.

  9. Mechanically refuelable zinc/air electric vehicle cells

    NASA Astrophysics Data System (ADS)

    Noring, J.; Gordon, S.; Maimoni, A.; Spragge, M.; Cooper, J. F.

    1992-12-01

    Refuelable zinc/air batteries have long been considered for motive as well as stationary power because of a combination of high specific energy, low initial cost, and the possibility of mechanical recharge by electrolyte exchange and additions of metallic zinc. In this context, advanced slurry batteries, stationary packed bed cells, and batteries offering replaceable cassettes have been reported recently. The authors are developing self-feeding, particulate-zinc/air batteries for electric vehicle applications. Emissionless vehicle legislation in California motivated efforts to consider a new approach to providing an electric vehicle with long range (400 km), rapid refueling (10 minutes) and highway safe acceleration - factors which define the essential functions of common automobiles. Such an electric vehicle would not compete with emerging secondary battery vehicles in specialized applications (commuting vehicles, delivery trucks). Rather, different markets would be sought where long range or rapid range extension are important. Examples are: taxis, continuous-duty fork-lift trucks and shuttle busses, and general purpose automobiles having modest acceleration capabilities. In the long range, a mature fleet would best use regional plants to efficiently recover zinc from battery reaction products. One option would be to use chemical/thermal reduction to recover the zinc. The work described focuses on development of battery configurations which efficiently and completely consume zinc particles, without clogging or changing discharge characteristics.

  10. Thin film solar cells

    SciTech Connect

    Klenk, R.; Schock, H.W.

    1994-12-31

    Within a comparatively short time the research on thin film solar cells has led to photovoltaic conversion efficiencies exceeding 16% which makes this technology a viable candidate for widespread applications. The contribution focuses on major issues of the design and implementation of cells based on Cu-III-VI{sub 2} chalcopyrite absorber thin films. The flexibility of this system leads to a large degree of freedom for the preparation as well as the electronic structure of the cell. Characterization of films and cells is not straightforward and there are still several important aspects that are not yet fully understood. Nevertheless, useful models have been derived for growth mechanisms, surface properties, interface formation, recombination paths and photo current collection using a combination of several independent characterization methods and numerical simulations. The substrate and back contact as well as secondary phases, mainly binary copper chalcogenides and copper poor ternaries, are having a significant influence. Different compounds have been investigated for the buffer layer between absorber and TCO (transparent conductive oxide) front contact. The highest efficiencies have been obtained with absorber band gaps less than 1.4 eV using a (very thin) CdS buffer and a ZnO TCO. The performance of various thin film solar cells will be briefly summarized.

  11. Zinc

    MedlinePLUS

    ... Guidelines for Americans and the U.S. Department of Agriculture's food guidance system, ChooseMyPlate . Where can I find ... on food sources of zinc: U.S. Department of Agriculture's (USDA’s) National Nutrient Database Nutrient List for zinc ( ...

  12. A Proton-Dependent Zinc Uptake in PC12 Cells Rengarajan V. Balaji1,2

    E-print Network

    A Proton-Dependent Zinc Uptake in PC12 Cells Rengarajan V. Balaji1,2 and Robert A. Colvin1 loading' the cells and the effect of such a change on radioactive zinc uptake was studied. It was found that zinc uptake was stimulated in cells loaded with protons without causing any measurable change

  13. Solar Energy Materials & Solar Cells 91 (2007) 13881391 Bifacial configurations for CdTe solar cells

    E-print Network

    Romeo, Alessandro

    2007-01-01

    Solar Energy Materials & Solar Cells 91 (2007) 1388­1391 Bifacial configurations for CdTe solar in the CdTe device. Reproducible solar cells exceeding 10% efficiency on the front side illumination, a promising efficiency of about 9% and proved stability for these solar cells has been developed [11]. Our Cd

  14. Fabrication and testing of large size nickel-zinc cells

    NASA Technical Reports Server (NTRS)

    Klein, M.

    1977-01-01

    The design and construction of nickel zinc cells, containing sintered nickel electrodes and asbestos coated inorganic separator materials, were outlined. Negative electrodes were prepared by a dry pressing process while various inter-separators were utilized on the positive electrodes, consisting of non-woven nylon, non-woven polypropylene, and asbestos.

  15. Electrolyte Loss Tendencies of Primary Silver-Zinc Cells

    NASA Technical Reports Server (NTRS)

    Thaller, Lawrence H.; Juvinall, Gordon L.

    1997-01-01

    Since silver zinc cells are not hermetically sealed, care must be taken to prevent the loss of electrolyte which can result in shorting paths within the battery box. Prelaunch battery processing is important in being able to minimize any problems with expelled electrolyte.

  16. Epitaxial solar cells fabrication

    NASA Technical Reports Server (NTRS)

    Daiello, R. V.; Robinson, P. H.; Kressel, H.

    1975-01-01

    Silicon epitaxy has been studied for the fabrication of solar cell structures, with the intent of optimizing efficiency while maintaining suitability for space applications. SiH2CL2 yielded good quality layers and junctions with reproducible impurity profiles. Diode characteristics and lifetimes in the epitaxial layers were investigated as a function of epitaxial growth conditions and doping profile, as was the effect of substrates and epitaxial post-gettering on lifetime. The pyrolytic decomposition of SiH4 was also used in the epitaxial formation of highly doped junction layers on bulk Si wafers. The effects of junction layer thickness and bulk background doping level on cell performance, in particular, open-circuit voltage, were investigated. The most successful solar cells were fabricated with SiH2 CL2 to grow p/n layers on n(+) substrates. The best performance was obtained from a p(+)/p/n/n(+) structure grown with an exponential grade in the n-base layer.

  17. High-efficiency GaAs and GaInP solar cells grown by all solid-state molecular-beam-epitaxy

    PubMed Central

    2011-01-01

    We report the initial results of GaAs and GaInP solar cells grown by all solid-state molecular-beam-epitaxy (MBE) technique. For GaAs single-junction solar cell, with the application of AlInP as the window layer and GaInP as the back surface field layer, the photovoltaic conversion efficiency of 26% at one sun concentration and air mass 1.5 global (AM1.5G) is realized. The efficiency of 16.4% is also reached for GaInP solar cell. Our results demonstrate that the MBE-grown phosphide-contained III-V compound semiconductor solar cell can be quite comparable to the metal-organic-chemical-vapor-deposition-grown high-efficiency solar cell. PMID:22040124

  18. Gate tunable monolayer MoS2/InP heterostructure solar cells

    NASA Astrophysics Data System (ADS)

    Lin, Shisheng; Wang, Peng; Li, Xiaoqiang; Wu, Zhiqian; Xu, Zhijuan; Zhang, Shengjiao; Xu, Wenli

    2015-10-01

    We demonstrate monolayer molybdenum disulfide (MoS2)/indium phosphide (InP) van der Waals heterostructure with remarkable photovoltaic response. Furthermore, benefiting from the atomically thin and semiconductor nature of MoS2, we have designed the gate tunable MoS2/InP heterostructure. Applied with a top gate voltage, the Fermi level of MoS2 is effectively tuned, and the barrier height at the MoS2/InP heterojunction correspondingly changes. The power conversion efficiency of MoS2/InP solar cells has reached a value of 7.1% under AM 1.5G illumination with a gate voltage of +6 V. The tunable MoS2/InP heterostructure may be promising for highly efficient solar cells.

  19. Monolithic tandem solar cell

    DOEpatents

    Wanlass, Mark W. (Golden, CO)

    1994-01-01

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

  20. Photoelectric solar cell array

    SciTech Connect

    Lidorenko, N.S.; Afian, V.V.; Martirosian, R.G.; Ryabikov, S.V.; Strebkov, D.S.; Vartanian, A.V.

    1983-11-29

    A photoelectric solar cell device comprises a dispersing element exposed to the sun's radiation and followed in the optical path by photocells having different spectral sensitivities. Each photocell has its working surface so oriented that the light beam with the wavelength corresponding to the maximum spectral sensitivity of that photocell impinges on its working surface. The dispersing element is a hologram representing light sources with different wavelengths. The photocells are positioned in the image planes of the light sources producing the light beams of the corresponding wavelengths.

  1. Floating emitter solar cell

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

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

  2. Monolithic tandem solar cell

    DOEpatents

    Wanlass, M.W.

    1994-06-21

    A single-crystal, monolithic, tandem, photovoltaic solar cell is described which includes (a) an InP substrate having upper and lower surfaces, (b) a first photoactive subcell on the upper surface of the InP substrate, (c) a second photoactive subcell on the first subcell; and (d) an optically transparent prismatic cover layer over the second subcell. The first photoactive subcell is GaInAsP of defined composition. The second subcell is InP. The two subcells are lattice matched. 9 figs.

  3. Solar cell module lamination process

    DOEpatents

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

    2002-01-01

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

  4. Zinc

    MedlinePLUS

    ... diarrhea , eye and skin sores and loss of appetite. Weight loss, problems with wound healing, decreased ability ... too much zinc include nausea, vomiting, loss of appetite, stomach cramps, diarrhea, and headaches. When people take ...

  5. Zinc

    MedlinePLUS

    ... lower respiratory infections. It is also used for malaria and other diseases caused by parasites. Some people ... decrease the risk for upper respiratory tract infections. Malaria. Taking zinc by mouth does not seem to ...

  6. Screening-Engineered Field-Effect Solar Cells William Regan,,,

    E-print Network

    Zettl, Alex

    the promising but hard-to-dope metal oxides, sulfides, and phosphides.3 Prototype SFPV devices have been at the MIS interface. Unfortu- nately, MIS cells, though sporting impressive efficiencies,4-6 typically have at direct field- effect "doping" of semiconductors, in which the voltage is externally applied to a gate

  7. Low zinc environment induces stress signaling, senescence and mixed cell death modalities in colon cancer cells.

    PubMed

    Rudolf, Emil; Rudolf, Kamil

    2015-12-01

    Currently it is not clear what type of the final cellular response (i.e. cell death modality or senescence) is induced upon chronic intracellular zinc depletion in colon cancer cells. To address this question, isogenic colon cancer lines SW480 and SW620 exposed to low zinc environment were studied over the period of 6 weeks. Low zinc environment reduced total as well as free intracellular zinc content in both cell lines. Decreased intracellular zinc content resulted in changes in cellular proliferation, cell cycle distribution and activation of stress signaling. In addition, colonocytes with low zinc content displayed increased levels of oxidative stress, changes in mitochondrial activity but in the absence of significant DNA damage. Towards the end of treatment (4th-6th week), exposed cells started to change morphologically, and typical markers of senescence as well as cell death appeared. Of two examined colon cancer cell lines, SW480 cells proved to activate predominantly senescent phenotype, with frequent form of demise being necrosis and mixed cell death modality but not apoptosis. Conversely, SW620 cells activated mostly cell death, with relatively equal distribution of apoptosis and mixed types, while senescent phenotypes and necrosis were present only in a small fraction of cell populations. Addition of zinc at the beginning of 4th week of treatment significantly suppressed cell death phenotypes in both cell lines but had no significant effect on senescence. In conclusion, presented results demonstrate variability of responses to chronic zinc depletion in colon cancer as modeled in vitro. PMID:26446979

  8. Carbon Nanotube Solar Cells

    PubMed Central

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

    2012-01-01

    We present proof-of-concept all-carbon solar cells. They are made of a photoactive side of predominantly semiconducting nanotubes for photoconversion and a counter electrode made of a natural mixture of carbon nanotubes or graphite, connected by a liquid electrolyte through a redox reaction. The cells do not require rare source materials such as In or Pt, nor high-grade semiconductor processing equipment, do not rely on dye for photoconversion and therefore do not bleach, and are easy to 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. PMID:22655070

  9. Schottky barrier solar cell

    NASA Technical Reports Server (NTRS)

    Stirn, R. J.; Yeh, Y. C. M. (inventors)

    1981-01-01

    A method of fabricating a Schottky barrier solar cell is described. The cell consists of a thin substrate of low cost material with at least the top surface of the substrate being electrically conductive. A thin layer of heavily doped n-type polycrystalling germanium is deposited on the substrate after a passivation layer is deposited to prevent migration of impurities into the polycrystalline germanium. The polycrystalline germanium is recrystallized to increase the crystal sizes to serve as a base layer on which a thin layer of gallium arsenide is vapor-epitaxilly grown followed by a thermally-grown oxide layer. A metal layer is deposited on the oxide layer and a grid electrode is deposited to be in electrical contact with the top surface of the metal layer.

  10. Nanocystalline silicon solar cells

    NASA Astrophysics Data System (ADS)

    Rath, J. K.

    2009-07-01

    Nanocrystalline silicon material has made rapid progress in the last several years and at present it can be defined as real device quality as a photoactive layer for solar cells. A number of innovative ideas, such as the deposition at the crystalline to amorphous transition, at high pressure depletion condition, by taming of the ion energy, by grading of the material growth, at reduced unwanted dopant incorporation, have helped to reach an efficiency of 10% for single junction nanocrystalline silicon cells. In situ plasma and gas phase diagnosis have contributed to the fast optimisation of deposition process parameters. Deposition rate, open circuit voltage and light confinement are some of most critical issues that are currently pursued. Materials with a defect density as low as 1015 cm-3 have been made, however, they are still not good enough for n-p junctions; the device structure is still of drift type in a p-i-n or n-i-p configuration.

  11. Stray thermal influences in zinc fixed-point cells

    SciTech Connect

    Rudtsch, S.; Aulich, A.; Monte, C.

    2013-09-11

    The influence of thermal effects is a major uncertainty contribution to the calibration of Standard Platinum Resistance Thermometers (SPRTs) in fixed-point cells. Axial heat losses strongly depend on the fixed-point temperature, constructional details of cells and SPRTs and the resulting heat transfer between cell, thermometer, furnace and environment. At the zinc point contributions by heat conduction and thermal radiation must be considered. Although the measurement of temperature gradients in the re-entrant well of a fixed-point cell provides very important information about the influence of axial heat losses, further investigations are required for a reliable estimate of the resulting uncertainty contribution. It is shown that specific modifications of a zinc fixed-point cell, following generally accepted principles, may result in systematic deviations of the measured fixed-point temperatures larger than typically stated in the uncertainty budget of National Metrology Institutes (NMIs). The underlying heat transport processes are investigated and the consequences for the construction of zinc cells are discussed.

  12. DECREASED INTRACELLULAR ZINC IN HUMAN TUMORIGENIC PROSTATE EPITHELIAL CELLS: A POSSIBLE ROLE IN PROSTATE CANCER PROGRESSION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zinc plays important roles in maintaining normal function of the prostate and in tumorigenesis of prostate epithelia. Evidence has shown that prostate malignant epithelial cells contain much less cellular zinc than the surrounding normal epithelial cells. We characterized the zinc homeostatic featur...

  13. Solar Panel of Photovoltaic Cells

    USGS Multimedia Gallery

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

  14. Inversion layer MOS solar cells

    NASA Technical Reports Server (NTRS)

    Ho, Fat Duen

    1986-01-01

    Inversion layer (IL) Metal Oxide Semiconductor (MOS) solar cells were fabricated. The fabrication technique and problems are discussed. A plan for modeling IL cells is presented. Future work in this area is addressed.

  15. Lunar production of solar cells

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Perino, Maria Antonietta

    1989-01-01

    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.

  16. Phosphidation of Li4Ti5O12 nanoparticles and their electrochemical and biocompatible superiority for lithium rechargeable batteries.

    PubMed

    Jo, Mi Ru; Nam, Ki Min; Lee, Youngmin; Song, Kyeongse; Park, Joon T; Kang, Yong-Mook

    2011-11-01

    Phosphidated-Li(4)Ti(5)O(12) shows high capacity with a significantly enhanced kinetics opening new possibilities for ultra-fast charge/discharge of lithium rechargeable batteries. The in vitro cytotoxicity test proves its fabulous cell viability, indicating that the toxicity problem of nanoparticles can be also solved by phosphidation. PMID:21952411

  17. Solar-Cell-Manufacturing System

    NASA Technical Reports Server (NTRS)

    Kelly, F. G.

    1984-01-01

    Cost of manufacturing solar arrays minimized by using polyimide-ribbed substrates together with silver-plated coils of low-expansion nickel/iron ribbon on solar cells. Polyimide taped to ribbon protects cell from abrasion or from sticking to other tooling.

  18. An Introduction to Solar Cells

    ERIC Educational Resources Information Center

    Feldman, Bernard J.

    2010-01-01

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

  19. Supramolecular solar cells

    NASA Astrophysics Data System (ADS)

    Subbaiyan, Navaneetha Krishnan

    Supramolecular chemistry - chemistry of non-covalent bonds including different type of intermolecular interactions viz., ion-pairing, ion-dipole, dipole-dipole, hydrogen bonding, cation-pi and Van der Waals forces. Applications based on supramolecular concepts for developing catalysts, molecular wires, rectifiers, photochemical sensors have been evolved during recent years. Mimicking natural photosynthesis to build energy harvesting devices has become important for generating energy and solar fuels that could be stored for future use. In this dissertation, supramolecular chemistry is being explored for creating light energy harvesting devices. Photosensitization of semiconductor metal oxide nanoparticles, such as titanium dioxide (TiO2) and tin oxide (SnO2,), via host-guest binding approach has been explored. In the first part, self-assembly of different porphyrin macrocyclic compounds on TiO2 layer using axial coordination approach is explored. Supramolecular dye sensitized solar cells built based on this approach exhibited Incident Photon Conversion Efficiency (IPCE) of 36% for a porphyrin-ferrocene dyad. In the second part, surface modification of SnO2 with water soluble porphyrins and phthalocyanine resulted in successful self-assembly of dimers on SnO2 surface. IPCE more than 50% from 400 - 700 nm is achieved for the supramolecular self-assembled heterodimer photocells is achieved. In summary, the axial ligation and ion-pairing method used as supramolecular tools to build photocells, exhibited highest quantum efficiency of light energy conversion with panchromatic spectral coverage. The reported findings could be applied to create interacting molecular systems for next generation of efficient solar energy harvesting devices.

  20. Heteroepitaxial InP, and ultrathin, directly glassed, GaAs 3-5 solar cells

    NASA Technical Reports Server (NTRS)

    Hardingham, C. M.; Cross, T. A.

    1993-01-01

    The commercial application of Indium Phosphide solar cells in practical space missions is crucially dependent upon achieving a major cost reduction which could be offered by heteroepitaxy on cheaper, more rugged substrates. Furthermore, significant mass reduction, compatibility with mechanically stacked multijunction cells, and elimination of the current loss through glue discoloration, is possible in III-V solar cells by the development of ultrathin, directly glassed cells. The progress of a UK collaborative program to develop high efficiency, homojunction InP solar cells, grown by MOCVD on Si substrates, is described. Results of homoepitaxial cells (is greater than 17 percent 1 Sun AM0) are presented, together with progress in achieving low dislocation density heteroepitaxy. Also, progress in a UK program to develop ultrathin directly-glassed GaAs cells is described. Ultrathin (5 micron) GaAs cells, with 1 Sun AM0 efficiencies up to 19.1 percent, are presented, together with progress in achieving a direct (adhesive-less) bond between the cell and coverglass. Consequential development to, for example, cell grids, are also discussed.

  1. Commercialization of Novel Organic Solar Cells

    E-print Network

    Kassegne, Samuel Kinde

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

  2. The challenges of organic polymer solar cells

    E-print Network

    Saif Addin, Burhan K. (Burhan Khalid)

    2011-01-01

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

  3. Controlled reflectance solar cell

    SciTech Connect

    Dill, H.G.; Lillington, D.R.

    1989-06-13

    A solar cell is described comprising: A semiconductor body having a front layer of a first conductivity type and an adjacent back layer of a second conductivity type opposite of the first conductivity type. The front and back layers form front and back major surfaces, respectively the semiconductor body further having openings through the back major surface and back layer which form recesses extending to the front layer. The recesses having walls which are doped to the first conductivity type; a first electrical contact disposed in the recesses making electrical contact the first conductivity type layer; and a second electrical contact disposed on the back major surface making electrical contact to the second conductivity type layer.

  4. Upconversion in solar cells

    PubMed Central

    2013-01-01

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

  5. GaAs Solar Cell Radiation Handbook

    NASA Technical Reports Server (NTRS)

    Anspaugh, B. E.

    1996-01-01

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

  6. Series Connection of Solar Cells

    NASA Technical Reports Server (NTRS)

    Keenan, R.

    1985-01-01

    Roll soldering from continuous string of cells. Automatic, continuous process attaches interconnecting strips to series string of silicon solar cells. Manufacturing process attaches each conductor from positive side of one cell to negative side of next. For reliability, 22 contacts are soldered on each side of each cell.

  7. Recent Developments in Silver/Zinc Rechargeable Cell Studies

    NASA Technical Reports Server (NTRS)

    Lewis, Harlan L.

    2001-01-01

    This viewgraph presentation discusses silver/zinc cell casing configurations and test results examining discharge capacity and silver migration comparisons. The following recommendations were proposed: 1) Use silver-treated cellophane instead of clear cellophane; 2) Use split wrap for cellophane whenever possible; and 3) Strongly consider use of sausage casing with PVA film in the following configuration: 1-mil (tubular) SC/1-mil PVA film/2.3-mil plain or 6-mil fiber-reinforced SC tubular.

  8. Managing aluminum phosphide poisonings

    PubMed Central

    Gurjar, Mohan; Baronia, Arvind K; Azim, Afzal; Sharma, Kalpana

    2011-01-01

    Aluminum phosphide (AlP) is a cheap, effective and commonly used pesticide. However, unfortunately, it is now one of the most common causes of poisoning among agricultural pesticides. It liberates lethal phosphine gas when it comes in contact either with atmospheric moisture or with hydrochloric acid in the stomach. The mechanism of toxicity includes cellular hypoxia due to the effect on mitochondria, inhibition of cytochrome C oxidase and formation of highly reactive hydroxyl radicals. The signs and symptoms are nonspecific and instantaneous. The toxicity of AlP particularly affects the cardiac and vascular tissues, which manifest as profound and refractory hypotension, congestive heart failure and electrocardiographic abnormalities. The diagnosis of AlP usually depends on clinical suspicion or history, but can be made easily by the simple silver nitrate test on gastric content or on breath. Due to no known specific antidote, management remains primarily supportive care. Early arrival, resuscitation, diagnosis, decrease the exposure of poison (by gastric lavage with KMnO4, coconut oil), intensive monitoring and supportive therapy may result in good outcome. Prompt and adequate cardiovascular support is important and core in the management to attain adequate tissue perfusion, oxygenation and physiologic metabolic milieu compatible with life until the tissue poison levels are reduced and spontaneous circulation is restored. In most of the studies, poor prognostic factors were presence of acidosis and shock. The overall outcome improved in the last decade due to better and advanced intensive care management. PMID:21887030

  9. InGaP Heterojunction Barrier Solar Cells

    NASA Technical Reports Server (NTRS)

    Welser, Roger E.

    2010-01-01

    A new solar-cell structure utilizes a single, ultra-wide well of either gallium arsenide (GaAs) or indium-gallium-phosphide (InGaP) in the depletion region of a wide bandgap matrix, instead of the usual multiple quantum well layers. These InGaP barrier layers are effective at reducing diode dark current, and photogenerated carrier escape is maximized by the proper design of the electric field and barrier profile. With the new material, open-circuit voltage enhancements of 40 and 100 mV (versus PIN control systems) are possible without any degradation in short-circuit current. Basic tenets of quantum-well and quantum- dot solar cells are utilized, but instead of using multiple thin layers, a single wide well works better. InGaP is used as a barrier material, which increases open current, while simultaneously lowering dark current, reducing both hole diffusion from the base, and space charge recombination within the depletion region. Both the built-in field and the barrier profile are tailored to enhance thermionic emissions, which maximizes the photocurrent at forward bias, with a demonstrated voltage increase. An InGaP heterojunction barrier solar cell consists of a single, ultra-wide GaAs, aluminum-gallium-arsenide (AlGaAs), or lower-energy-gap InGaP absorber well placed within the depletion region of an otherwise wide bandgap PIN diode. Photogenerated electron collection is unencumbered in this structure. InGaAs wells can be added to the thick GaAs absorber layer to capture lower-energy photons.

  10. Improving the efficiency of copper indium gallium (Di-)selenide (CIGS) solar cells through integration of a moth-eye textured resist with a refractive index similar to aluminum doped zinc oxide

    NASA Astrophysics Data System (ADS)

    Burghoorn, M.; Kniknie, B.; van Deelen, J.; Xu, M.; Vroon, Z.; van Ee, R.; van de Belt, R.; Buskens, P.

    2014-12-01

    Textured transparent conductors are widely used in thin-film silicon solar cells. They lower the reflectivity at interfaces between different layers in the cell and/or cause an increase in the path length of photons in the Si absorber layer, which both result in an increase in the number of absorbed photons and, consequently, an increase in short-circuit current density (Jsc) and cell efficiency. Through optical simulations, we recently obtained strong indications that texturing of the transparent conductor in copper indium gallium (di-)selenide (CIGS) solar cells is also optically advantageous. Here, we experimentally demonstrate that the Jsc and efficiency of CIGS solar cells with an absorber layer thickness (dCIGS) of 0.85 ?m, 1.00 ?m and 2.00 ?m increase through application of a moth-eye textured resist with a refractive index that is sufficiently similar to AZO (nresist = 1.792 vs. nAZO = 1.913 at 633 nm) to avoid large optical losses at the resist-AZO interface. On average, Jsc increases by 7.2%, which matches the average reduction in reflection of 7.0%. The average relative increase in efficiency is slightly lower (6.0%). No trend towards a larger relative increase in Jsc with decreasing dCIGS was observed. Ergo, the increase in Jsc can be fully explained by the reduction in reflection, and we did not observe any increase in Jsc based on an increased photon path length.

  11. Multiple Exciton Generation Solar Cells

    SciTech Connect

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

    2012-01-01

    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%.

  12. Zinc and its transporters, pancreatic beta cells, and insulin metabolism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zinc is an essential trace metal for life. Two families of zinc transporters, SLC30A (ZnT) and SLC39A (ZIP) are required for maintaining cellular zinc homeostasis. ZnTs function to decrease cytoplasmic zinc concentrations whereas ZIPs do the opposite. Expression of zinc transporters can be tissue/ce...

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

    E-print Network

    Romeo, Alessandro

    2006-01-01

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

  14. Module level solutions to solar cell polarization

    DOEpatents

    Xavier, Grace (Fremont, CA), Li; Bo (San Jose, CA)

    2012-05-29

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

  15. Fishy Business: Effect of Omega-3 Fatty Acids on Zinc Transporters and Free Zinc Availability in Human Neuronal Cells

    PubMed Central

    De Mel, Damitha; Suphioglu, Cenk

    2014-01-01

    Omega-3 (?-3) fatty acids are one of the two main families of long chain polyunsaturated fatty acids (PUFA). The main omega-3 fatty acids in the mammalian body are ?-linolenic acid (ALA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Central nervous tissues of vertebrates are characterized by a high concentration of omega-3 fatty acids. Moreover, in the human brain, DHA is considered as the main structural omega-3 fatty acid, which comprises about 40% of the PUFAs in total. DHA deficiency may be the cause of many disorders such as depression, inability to concentrate, excessive mood swings, anxiety, cardiovascular disease, type 2 diabetes, dry skin and so on. On the other hand, zinc is the most abundant trace metal in the human brain. There are many scientific studies linking zinc, especially excess amounts of free zinc, to cellular death. Neurodegenerative diseases, such as Alzheimer’s disease, are characterized by altered zinc metabolism. Both animal model studies and human cell culture studies have shown a possible link between omega-3 fatty acids, zinc transporter levels and free zinc availability at cellular levels. Many other studies have also suggested a possible omega-3 and zinc effect on neurodegeneration and cellular death. Therefore, in this review, we will examine the effect of omega-3 fatty acids on zinc transporters and the importance of free zinc for human neuronal cells. Moreover, we will evaluate the collective understanding of mechanism(s) for the interaction of these elements in neuronal research and their significance for the diagnosis and treatment of neurodegeneration. PMID:25195602

  16. Plasma Etching Improves Solar Cells

    NASA Technical Reports Server (NTRS)

    Bunyan, S. M.

    1982-01-01

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

  17. In-Situ Hydrothermal Growth of Bi-Hierarchical ZnO Nanoarchitecture with Surface Modification for Efficient Hybrid Solar Cells

    E-print Network

    Cao, Guozhong

    boosting the ultimate photoelectric conversion efficiency of organic-inorganic hybrid solar cells (HSCs for Efficient Hybrid Solar Cells Yan-Zhen Zheng a,b , Haiyang Ding c , Yu Liu a , Xia Tao a, *, Guozhong Cao d-inorganic hybrid solar cells dye surface modification hierarchical zinc oxide nanoarchitecture one-dimension A B

  18. NREL Spurred the Success of Multijunction Solar Cells (Fact Sheet)

    SciTech Connect

    Not Available

    2013-08-01

    Many scientists once believed that high-quality gallium indium phosphide (GaInP) alloys could not be grown for use as semiconductors because the alloys would separate. However, researchers at the National Renewable Energy Laboratory (NREL) thought differently, and they employed GaInP in a material combination that allowed the multijunction cell to flourish. The multijunction cell is now the workhorse that powers satellites and the catalyst for renewed interest in concentrator photovoltaic products.

  19. Long-term temperature effects on GaAs solar cells

    NASA Technical Reports Server (NTRS)

    Heinbockel, J. H.; Hong, K. H.

    1979-01-01

    The thermal degradation of AlGaAs solar cells resulting from a long-term operation in a space environment is investigated. The solar cell degradation effects caused by zinc and aluminum diffusion as well as deterioration by arsenic evaporation are presented. Also, the results are presented of experimental testing and measurements of various GaAs solar cell properties while the solar cell was operating in the temperature range of 27 C to 350 C. In particular, the properties of light current voltage curves, dark current voltage curves, and spectral response characteristics are given. Finally, some theoretical models for the annealing of radiation damage over various times and temperatures are included.

  20. Terrestrial concentrator solar cell module

    SciTech Connect

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

    1992-06-02

    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.

  1. Diffusion lengths in irradiated N/P InP-on-Si solar cells

    NASA Technical Reports Server (NTRS)

    Wojtczuk, Steven; Colerico, Claudia; Summers, Geoffrey P.; Walters, Robert J.; Burke, Edward A.

    1995-01-01

    Indium phosphide (InP) solar cells are being made on silicon (Si) wafers (InP/Si) to take advantage of both the radiation-hardness properties of the InP solar cell and the light weight and low cost of Si wafers compared to InP or germanium (Ge) wafers. The InP/Si cell application is for long duration and/or high radiation orbit space missions. InP/Si cells have higher absolute efficiency after a high radiation dose than gallium arsenide (GaAs) or silicon (Si) solar cells. In this work, base electron diffusion lengths in the N/P cell are extracted from measured AM0 short-circuit photocurrent at various irradiation levels out to an equivalent 1 MeV fluence of 1017 1 MeV electrons/sq cm for a 1 sq cm 12% BOL InP/Si cell. These values are then checked for consistency by comparing measured Voc data with a theoretical Voc model that includes a dark current term that depends on the extracted diffusion lengths.

  2. Solar cell with back side contacts

    DOEpatents

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

    2013-12-24

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

  3. EE580 Solar Cells Todd J. Kaiser

    E-print Network

    Kaiser, Todd J.

    & unlimited potential ­ Long term benefits undeniable Montana State University: Solar Cells Lecture 107/21/2010 1 EE580 ­ Solar Cells Todd J. Kaiser · Lecture 10 · Summary 1Montana State University: Solar Cells Lecture 10: Summary Summer 2010 Class Montana State University: Solar Cells Lecture 10

  4. Solar Energy Materials & Solar Cells 91 (2007) 15991610 Improving solar cell efficiency using photonic band-gap materials

    E-print Network

    Dowling, Jonathan P.

    2007-01-01

    Solar Energy Materials & Solar Cells 91 (2007) 1599­1610 Improving solar cell efficiency using efficiency of solar cell devices without using concentrators. r 2007 Elsevier B.V. All rights reserved) solar energy conversion systems (or solar cells) are the most widely used power systems. However

  5. Estimation of minority carrier diffusion lengths in InP/GaAs solar cells

    NASA Technical Reports Server (NTRS)

    Jain, R. K.; Flood, D. J.

    1990-01-01

    Minority carrier diffusion length is one of the most important parameters affecting the solar cell performance. An attempt is made to estimate the minority carrier diffusion lengths is the emitter and base of InP/GaAs heteroepitaxial solar cells. The PC-1D computer model was used to simulate the experimental cell results measured at NASA Lewis under AMO (air mass zero) spectrum at 25 C. A 16 nm hole diffusion length in the emitter and a 0.42 micron electron diffusion length in the base gave very good agreement with the I-V curve. The effect of varying minority carrier diffusion lengths on cell short current, open circuit voltage, and efficiency was studied. It is also observed that the front surface recombination velocity has very little influence on the cell performance. The poor output of heteroepitaxial cells is caused primarily by the large number of dislocations generated at the interfaces that propagate through the bulk indium phosphide layers. Cell efficiency as a function of dislocation density was calculated and the effect of improved emitter bulk properties on cell efficiency is presented. It is found that cells with over 16 percent efficiencies should be possible, provided the dislocation density is below 10(exp 6)/sq cm.

  6. The monitoring possibility of some mammalian cells for zinc concentrations on metallic materials.

    PubMed

    Ogawa, Akiko; Okuda, Naoaki; Hio, Katsuya; Kanematsu, Hideyuki; Tamauchi, Hidekazu

    2012-05-01

    Zinc plating is widely used to protect steels against corrosion. However, the possibility of a high environmental risk for zinc has been recently discussed among advanced countries and more environmentally-friendly substitutes are required urgently. Therefore, monitoring zinc concentration changes on metallic materials such as steel is very important. We chose to measure zinc concentration changes in some mammalian cells and confirmed that V79 cells were highly sensitive to changes in zinc concentrations. In this study, the following process was applied to the proprietary production for tin-zinc alloy films on steel using V79 cells. Specimens were immersed in PBS to produce extracts. Zinc concentrations in the extracts almost corresponded to zinc concentrations on steel surfaces. When extracts were added to a V79 cell culture, colony formation was inhibited, and inhibition increased with increases in zinc concentrations. Changes in zinc concentrations on steel surfaces with heat treatment could be monitored relatively well by V79 cells, even though the results were still semi-quantitative. PMID:22331507

  7. Dust Removal from Solar Cells

    NASA Technical Reports Server (NTRS)

    Ashpis, David E. (Inventor)

    2015-01-01

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

  8. Dust removal from solar cells

    NASA Technical Reports Server (NTRS)

    Ashpis, David E. (Inventor)

    2011-01-01

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

  9. Solar Energy Materials & Solar Cells 90 (2006) 34073415 High-efficiency flexible CdTe solar cells

    E-print Network

    Romeo, Alessandro

    2006-01-01

    Solar Energy Materials & Solar Cells 90 (2006) 3407­3415 High-efficiency flexible CdTe solar cellsTe/CdS solar cells of 11% efficiency in superstrate and 7.3% efficiency in substrate configurations have been at the beginning and at the end of the cell fabrication process. Solar cells with AM1.5 efficiency of 11

  10. The cytotoxic effects of titanium oxide and zinc oxide nanoparticles oh Human Cervical Adenocarcinoma cell membranes

    NASA Astrophysics Data System (ADS)

    Mironava, Tatsiana; Applebaum, Ariella; Applebaum, Eliana; Guterman, Shoshana; Applebaum, Kayla; Grossman, Daniel; Gordon, Chris; Brink, Peter; Wang, H. Z.; Rafailovich, Miriam

    2013-03-01

    The importance of titanium dioxide (TiO2) and zinc oxide (ZnO), inorganic metal oxides nanoparticles (NPs) stems from their ubiquitous applications in personal care products, solar cells and food whitening agents. Hence, these NPs come in direct contact with the skin, digestive tracts and are absorbed into human tissues. Currently, TiO2 and ZnO are considered safe commercial ingredients by the material safety data sheets with no reported evidence of carcinogenicity or ecotoxicity, and do not classify either NP as a toxic substance. This study examined the direct effects of TiO2 and ZnO on HeLa cells, a human cervical adenocarcinonma cell line, and their membrane mechanics. The whole cell patch-clamp technique was used in addition to immunohistochemistry staining, TEM and atomic force microscopy (AFM). Additionally, we examined the effects of dexamethasone (DXM), a glucocorticoid steroid known to have an effect on cell membrane mechanics. Overall, TiO2 and ZnO seemed to have an adverse effect on cell membrane mechanics by effecting cell proliferation, altering cellular structure, decreasing cell-cell adhesion, activating existing ion channels, increasing membrane permeability, and possibly disrupting cell signaling.

  11. Zinc differentially regulates mitogen-activated protein kinases in human T cells.

    PubMed

    Hönscheid, Andrea; Dubben, Svenja; Rink, Lothar; Haase, Hajo

    2012-01-01

    Zinc is an essential nutrient with remarkable importance for immunity, in particular for T-cell function. This is, at least in part, based on an involvement of zinc ions in immune cell signal transduction; dynamic changes of the intracellular free zinc concentration have recently been recognized as signaling events. Because the molecular targets of zinc signals remain incompletely understood, we investigated the impact of elevated intracellular free zinc on mitogen-activated protein kinase (MAPK) activity and MAPK-dependent cytokine production in human T-cells. p38 was activated by treatment with zinc and the ionophore pyrithione, whereas ERK1/2 and c-Jun N-terminal kinases were unaffected. In contrast, after T-cell receptor stimulation with antibodies against CD3, ERK1/2-phosphorylation was selectively suppressed by intracellular zinc. Mechanisms that had been shown to mediate zinc-effects in other cells, such as activation of the Src kinase Lck, inhibition of the protein tyrosine phosphatase CD45 or MAPK phosphatases and cyclic nucleotide/protein kinase A signaling were not involved. This indicates that the differential impact of zinc on the MAPK families in T-cells is mediated by mechanisms that differ from the ones observed in other cell types. Further investigation of the activation of p38 by zinc demonstrated that this MAPK is responsible for the zinc-mediated activation of CREB and mRNA expression of the Th1 cytokines interferon-gamma and interleukin-2. In conclusion, regulation of MAPK activity contributes to the impact of zinc on T-cell function. PMID:21333516

  12. Screen-printable silver pastes with metallic nano-zinc and nano-zinc alloys for crystalline silicon photovoltaic cells.

    PubMed

    Ionkin, Alex S; Fish, Brian M; Li, Zhigang Rick; Lewittes, Mark; Soper, Paul D; Pepin, John G; Carroll, Alan F

    2011-02-01

    Silver metallization pastes for crystalline silicon PV cells containing nanosized metallic zinc were found to be superior to commercial pastes containing micrometer-sized metallic zinc and micrometer sized zinc oxide in terms of efficiency and firing window. Efficiency performance decreases as the size of the particles increases: nano-Zn > 3.6 ?m Zn > 4.4 ?m Zn. Advanced electron microscopy techniques were used to investigate the interfacial microstructure between the front-side contact and the Si emitter of nanosized zinc additive based cells fired at temperatures from below to above optimal. These microstructural observations confirmed the possibility of a tunneling mechanism of current flow (a "nano-Ag colloid assisted tunneling" model) in the absence of Ag crystallites. Contact resistance maps were used to guide sampling, leading to a better understanding of the relationship between microstructure and contact resistance. Low contact resistance and higher cell efficiency, especially at under- and overfiring temperature conditions, are due to more uniform silicon nitride etching obtained through the use of nanosized metallic zinc additives. PMID:21291277

  13. High-efficiency thin-film silicon-on-GaP solar cell for improved radiation resistance

    NASA Astrophysics Data System (ADS)

    Culik, Jerome S.

    1987-09-01

    The ultimate high efficiency silicon solar cell is a light trapping thin film silicon structure epitaxially grown on an oxide overcoated substrate such as silicon or gallium phosphide (GaP). In addition to high performance, this thin-base silicon device is more tolerant of radiation effects than a thick-base solar cell because this structure is less sensitive to reductions in minority-carrier diffusion length. The oxide overcoating layer, an integral part of this design, will serve as a dielectric back surface reflector leading to light trapping, and it will also eliminate dangling bonds in the overgrown silicon layer, effectively passivating the silicon-oxide interface and reducing back surface recombination.

  14. High Efficiency InP Solar Cells from Low Toxicity Tertiarybutylphosphine

    NASA Technical Reports Server (NTRS)

    Hoffman, Richard W., Jr.; Fatemi, Navid S.; Wilt, David M.; Jenkins, Phillip P.; Brinker, David J.; Scheiman, David A.

    1994-01-01

    Large scale manufacture of phosphide based semiconductor devices by organo-metallic vapor phase epitaxy (OMVPE) typically requires the use of highly toxic phosphine. Advancements in phosphine substitutes have identified tertiarybutylphosphine (TBP) as an excellent precursor for OMVPE of InP. High quality undoped and doped InP films were grown using TBP and trimethylindium. Impurity doped InP films were achieved utilizing diethylzinc and silane for p and n type respectively. 16 percent efficient solar cells under air mass zero, one sun intensity were demonstrated with Voc of 871 mV and fill factor of 82.6 percent. It was shown that TBP could replace phosphine, without adversely affecting device quality, in OMVPE deposition of InP thus significantly reducing toxic gas exposure risk.

  15. EE580 Solar Cells Todd J. Kaiser

    E-print Network

    Kaiser, Todd J.

    University: Solar Cells Lecture 9: PV Systems Several types of operating modes · Centralized power plant Cells loose efficiency with the increase in temperature Colder is better Solar Heating Montana State University: Solar Cells Lecture 9: PV Systems 11 Solar heating (70-90%) is more efficient than photovoltaic

  16. DETAIL OF ZINC CLEANER CELL INTERIOR (EXPOSED AT F/45 FOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF ZINC CLEANER CELL INTERIOR (EXPOSED AT F/45 FOR DEPTH OF FIELD PURPOSES). NOTE GALIGHER STYLE BAFFLES AND TENDENCY OF ZINC TO BUILD UP ON CELL COMPONENTS. - Shenandoah-Dives Mill, 135 County Road 2, Silverton, San Juan County, CO

  17. Fabrication of 7.2% efficient CZTSSe solar cells using CZTS nanocrystals.

    PubMed

    Guo, Qijie; Ford, Grayson M; Yang, Wei-Chang; Walker, Bryce C; Stach, Eric A; Hillhouse, Hugh W; Agrawal, Rakesh

    2010-12-15

    Earth abundant copper-zinc-tin-chalcogenide (CZTSSe) is an important class of material for the development of low cost and sustainable thin film solar cells. The fabrication of CZTSSe solar cells by selenization of CZTS nanocrystals is presented. By tuning the composition of the CZTS nanocrystals and developing a robust film coating method, a total area efficiency as high as 7.2% under AM 1.5 illumination and light soaking has been achieved. PMID:21090644

  18. Soybean extracts increase cell surface ZIP4 abundance and cellular zinc levels: a potential novel strategy to enhance zinc absorption by ZIP4 targeting.

    PubMed

    Hashimoto, Ayako; Ohkura, Katsuma; Takahashi, Masakazu; Kizu, Kumiko; Narita, Hiroshi; Enomoto, Shuichi; Miyamae, Yusaku; Masuda, Seiji; Nagao, Masaya; Irie, Kazuhiro; Ohigashi, Hajime; Andrews, Glen K; Kambe, Taiho

    2015-12-01

    Dietary zinc deficiency puts human health at risk, so we explored strategies for enhancing zinc absorption. In the small intestine, the zinc transporter ZIP4 functions as an essential component of zinc absorption. Overexpression of ZIP4 protein increases zinc uptake and thereby cellular zinc levels, suggesting that food components with the ability to increase ZIP4 could potentially enhance zinc absorption via the intestine. In the present study, we used mouse Hepa cells, which regulate mouse Zip4 (mZip4) in a manner indistinguishable from that in intestinal enterocytes, to screen for suitable food components that can increase the abundance of ZIP4. Using this ZIP4-targeting strategy, two such soybean extracts were identified that were specifically able to decrease mZip4 endocytosis in response to zinc. These soybean extracts also effectively increased the abundance of apically localized mZip4 in transfected polarized Caco2 and Madin-Darby canine kidney cells and, moreover, two apically localized mZip4 acrodermatitis enteropathica mutants. Soybean components were purified from one extract and soyasaponin Bb was identified as an active component that increased both mZip4 protein abundance and zinc levels in Hepa cells. Finally, we confirmed that soyasaponin Bb is capable of enhancing cell surface endogenous human ZIP4 in human cells. Our results suggest that ZIP4 targeting may represent a new strategy to improve zinc absorption in humans. PMID:26385990

  19. Solar cell circuit and method for manufacturing solar cells

    NASA Technical Reports Server (NTRS)

    Mardesich, Nick (Inventor)

    2010-01-01

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

  20. Zinc Induced G2/M Blockage is p53 and p21 Dependent in Normal Human Bronchial Epithelial Cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The involvement of the p53 and p21 signal pathway in the G2/M cell cycle progression of zinc supplemented normal human bronchial epithelial (NHBE) cells was examined using the siRNA approach. Cells were cultured for one passage in different concentrations of zinc: <0.4 microM (ZD) as zinc-deficient;...

  1. Crystal and electronic structures of CaAl{sub 2}Si{sub 2}-type rare-earth copper zinc phosphides RECuZnP{sub 2} (RE=Pr, Nd, Gd-Tm, Lu)

    SciTech Connect

    Blanchard, Peter E.R.; Stoyko, Stanislav S.; Cavell, Ronald G.; Mar, Arthur

    2011-01-15

    The quaternary rare-earth phosphides RECuZnP{sub 2} (RE=Pr, Nd, Gd-Tm, Lu) have been prepared by reaction of the elements at 900 {sup o}C, completing this versatile series which forms for nearly all RE metals. They adopt the trigonal CaAl{sub 2}Si{sub 2}-type structure (Pearson symbol hP5, space group P3-bar m1, Z=1), as confirmed by single-crystal X-ray diffraction analysis on ErCuZnP{sub 2} and powder X-ray diffraction analysis on the remaining members. The Cu and Zn atoms are assumed to be disordered over the single transition-metal site. Band structure calculations on a hypothetically ordered YCuZnP{sub 2} model suggest a semimetal, with a zero band gap between the valence and conduction bands. This electronic structure is supported by XPS valence band spectra for RECuZnP{sub 2} (RE=Gd-Er), in which the intensity drops off smoothly at the Fermi edge. The absence of a band gap permits the electron count to deviate from the precise value of 16 e{sup -} per formula unit, as demonstrated by the formation of a solid solution in GdCu{sub x}Zn{sub 2-x}P{sub 2} (1.0{<=}x{<=}1.3), while still retaining the CaAl{sub 2}Si{sub 2}-type structure. Because the Cu 2p XPS spectra indicate that the Cu atoms are always monovalent, the substitution of Cu for Zn leads to a decrease in electron count and a lowering of the Fermi level in the valence band. The magnetic susceptibility of RECuZnP{sub 2} (RE=Gd-Er), which obeys the Curie-Weiss law, confirms the presence of trivalent RE atoms. -- Graphical abstract: The absence of a band gap in the semimetallic quaternary rare-earth phosphides RECuZnP{sub 2} permits the formation of a solid solution such as GdCu{sub x}Zn{sub 2-x}P{sub 2} through hole-doping of the valence band. Display Omitted

  2. Dual battery sets including zinc MnO{sub 2} rechargeable cells on constant power tests

    SciTech Connect

    Schumm, B. Jr.

    1998-07-01

    Electric vehicle power requirements typically are much greater than what would be recommended for rechargeable zinc manganese dioxide alkaline batteries. In order to use the zinc manganese dioxide system as an economical power source for heavy load or pulse systems it is necessary to augment the pulse load carrying capability. Eagle-Cliffs is testing commercially available rechargeable zinc manganese dioxide cells in sets. These sets consist one configuration of the zinc manganese dioxide cells accompanied by a much lower capacity device ( which may be another configuration of zinc manganese dioxide cells) supporting any heavy pulse current requirements. Thus the zinc manganese dioxide cells provide at least a low cost, environmentally desirable main power battery and perhaps the pulse power yet the system still meets the intermittent high power needs of many uses. In this test program, small zinc manganese dioxide rechargeable cells are supported by a nickel cadmium battery or a different set of zinc manganese dioxide cells simulating any of a number of devices such as power batteries, large capacitors, flywheels, etc. Discharge performance demonstrating forty-five to fifty watt-hours per kilogram and 80 watts per kilogram is achieved by the system.

  3. Low cost solar cell arrays

    NASA Technical Reports Server (NTRS)

    Iles, P. A.; Mclennan, H.

    1975-01-01

    Limitations in both space and terrestial markets for solar cells are described. Based on knowledge of the state-of-the-art, six cell options are discussed; as a result of this discussion, the three most promising options (involving high, medium and low efficiency cells respectively) were selected and analyzed for their probable costs. The results showed that all three cell options gave promise of costs below $10 per watt in the near future. Before further cost reductions can be achieved, more R and D work is required; suggestions for suitable programs are given.

  4. Degradation characteristics of air cathode in zinc air fuel cells

    NASA Astrophysics Data System (ADS)

    Ma, Ze; Pei, Pucheng; Wang, Keliang; Wang, Xizhong; Xu, Huachi; Liu, Yongfeng; peng, Guanlin

    2015-01-01

    The zinc air fuel cell (ZAFC) is a promising candidate for electrical energy storage and electric vehicle propulsion. However, its limited durability has become a major obstacle for its successful commercialization. In this study, 2-cell stacks, 25 cm² cells and three-electrode half-cells are constructed to experimentally investigate the degradation characteristics of the air cathode. The results of electrochemical tests reveal that the peak power density for the 25 cm2 cell with a new air cathode is 454 mW cm-2, which is twice as the value of the used air cathode. The electrochemical impedance analysis shows that both the charge transfer resistance and the mass transfer resistance of the used air cathodes have increased, suggesting that the catalyst surface area and gas diffusion coefficient have decreased significantly. Additionally, the microstructure and morphology of the catalytic layer (CL) and gas diffusion layer (GDL) are characterized by scanning electron microscopes (SEM). SEM results confirm that the micropores in CL and GDL of the used air cathode are seriously clogged, and many catalyst particles are lost. Therefore, the performance degradation is mainly due to the clogging of micropores and loss of catalyst particles. Furthermore, hypotheses of degradation mechanism and mitigation strategies for GDL and CL are discussed briefly.

  5. Zinc inhibits the reproductive toxicity of Zearalenone in immortalized murine ovarian granular KK-1 cells.

    PubMed

    Li, Yijia; He, Xiaoyun; Yang, Xuan; Huang, Kunlun; Luo, Yunbo; Zhu, Liye; Li, Yuzhe; Xu, Wentao

    2015-01-01

    Zearalenone (ZEA) mainly injures the reproductive system of mammals. In the present study, we aimed to explore the mechanism by which zinc inhibits ZEA-induced reproductive damage in KK-1 cells for the first time. The results shown that both zinc sulfate and zinc gluconate addition increased the intracellular zinc concentration and influenced the expression of zinc transporters (Slc30a1 and Slc39a1) in a time-dependent manner. Co-incubation of zinc with ZEA significantly reduced the ZEA-induced reactive oxygen species and malondialdehyde elevation by promoting the transcription of Mtf1 and Mt2. Meanwhile, two different zincs inhibited the ZEA-induced loss of mitochondrial membrane potential and elevation of late-stage apoptosis via activating the mitochondrial apoptotic pathway by recovering the mRNA and protein expression of pro-apoptotic genes (Bax, Casp3, Casp9). Zinc also recovered cells from S-phase cell cycle arrest. In addition, both of them promoted the ZEA-induced estrogen production but regulated the expression of steroidogenic enzymes (Star, Cyp11a1, Hsd3b1, Cyp17a1) in different way. All these results indicated that zinc could inhibit the reproductive toxicity of ZEA. PMID:26395757

  6. Zinc inhibits the reproductive toxicity of Zearalenone in immortalized murine ovarian granular KK-1 cells

    PubMed Central

    Li, Yijia; He, Xiaoyun; Yang, Xuan; Huang, Kunlun; Luo, Yunbo; Zhu, Liye; Li, Yuzhe; Xu, Wentao

    2015-01-01

    Zearalenone (ZEA) mainly injures the reproductive system of mammals. In the present study, we aimed to explore the mechanism by which zinc inhibits ZEA-induced reproductive damage in KK-1 cells for the first time. The results shown that both zinc sulfate and zinc gluconate addition increased the intracellular zinc concentration and influenced the expression of zinc transporters (Slc30a1 and Slc39a1) in a time-dependent manner. Co-incubation of zinc with ZEA significantly reduced the ZEA-induced reactive oxygen species and malondialdehyde elevation by promoting the transcription of Mtf1 and Mt2. Meanwhile, two different zincs inhibited the ZEA-induced loss of mitochondrial membrane potential and elevation of late-stage apoptosis via activating the mitochondrial apoptotic pathway by recovering the mRNA and protein expression of pro-apoptotic genes (Bax, Casp3, Casp9). Zinc also recovered cells from S-phase cell cycle arrest. In addition, both of them promoted the ZEA-induced estrogen production but regulated the expression of steroidogenic enzymes (Star, Cyp11a1, Hsd3b1, Cyp17a1) in different way. All these results indicated that zinc could inhibit the reproductive toxicity of ZEA. PMID:26395757

  7. Zinc functions as a cytotoxic agent for prostate cancer cells independent of culture and growth conditions.

    PubMed

    Kriedt, Christopher L; Baldassare, Joseph; Shah, Maulik; Klein, Claudette

    2010-01-01

    The effects of zinc on the viability of PC3, LNCaP and DU145 prostate cancer cell lines in vitro were examined. The data indicate that, despite their distinctly different gene expression profiles, morphology and tissue origin, all cell lines responded to zinc in a similar time and dose dependent manner. Experiments using pyrithione indicated that cell death is mediated by internalized zinc. Zinc effects on cells plated as monolayers were compared to its effects on cells plated in a collagen matrix. Although the rate of cell growth in the matrix was delayed compared to cells in 2-dimensional cultures, the cytotoxic effects of zinc were unaltered. Using both 2-dimensional and 3-dimensional cultures, we observed that zinc cytotoxicity was independent of both the culture conditions and the rate of cell growth, results that contrast the activity of the current chemotherapeutics used to treat prostate cancer. The attractive properties of zinc cytotoxicity demonstrated in this paper suggest that is can be developed as a novel and effective chemotherapeutic agent for prostate cancer treatment. PMID:21222361

  8. Compensated amorphous silicon solar cell

    DOEpatents

    Carlson, David E. (Yardley, PA)

    1980-01-01

    An amorphous silicon solar cell incorporates a region of intrinsic hydrogenated amorphous silicon fabricated by a glow discharge wherein said intrinsic region is compensated by P-type dopants in an amount sufficient to reduce the space charge density of said region under illumination to about zero.

  9. Alining Solder Pads on a Solar Cell

    NASA Technical Reports Server (NTRS)

    Lazzery, A. G.

    1984-01-01

    Mechanism consisting of stylus and hand-operated lever incorporated into screening machine to precisely register front and back solder pads during solar-cell assembly. Technique may interest those assembling solar cells manually for research or prototype work.

  10. Evaluation of solar cell materials for a Solar Power Satellite

    NASA Technical Reports Server (NTRS)

    Glaser, P. E.; Almgren, D. W.; Csigi, K. I.

    1980-01-01

    Alternative solar cell materials being considered for the solar power satellite are described and price, production, and availability projections through the year 2000 are presented. The chief materials considered are silicon and gallium arsenide.

  11. Process of making solar cell module

    DOEpatents

    Packer, M.; Coyle, P.J.

    1981-03-09

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

  12. EE580 Solar Cells Todd J. Kaiser

    E-print Network

    Kaiser, Todd J.

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

  13. Key Physical Mechanisms in Nanostructured Solar Cells

    SciTech Connect

    Dr Stephan Bremner

    2010-07-21

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

  14. Life testing of secondary silver-zinc cells

    NASA Technical Reports Server (NTRS)

    Brewer, Jeffrey C.; Doreswamy, Rajiv

    1991-01-01

    Testing on a variety of secondary silver-zinc (Ag-Zn) cells has been in progress at the Marshall Space Flight Center (MSFC) for over six years. The latest test involves a 350-Ah cell design that has been cycled at 10 C for 16 months. This design has achieved over 7200 low-earth-orbit (LEO) cycles as well as 17 deep discharges at an 85 percent depth of discharge. This test not only is a life test on these cells but also addresses different methods of storing these cells between the deep discharges. As the test is approaching completion, some interesting results are being seen. In particular, two of the four packs currently on test have failed to meet the 35-h (295-Ah) deep discharge requirement that was arbitrarily set at the beginning of the test. This capacity loss failure is likely a result of the storage method used on these two packs between deep discharges. The two packs are LEO cycled in such a way as to minimize overcharge in an attempt to prolong life.

  15. 24% efficient silicon solar cells

    SciTech Connect

    Zhao, J.; Wang, A.; Altermatt, P.P.; Wenham, S.R.; Green, M.A.

    1994-12-31

    This paper reports significant progress in silicon solar cell performance, taking confirmed efficiency beyond 24% for the first time. This progress has been achieved by a combination of several mechanisms. One is the reduction of recombination at the cell front surface by improved passivation of the silicon/silicon dioxide interface. Resistive losses in the cell have been reduced by a double-plating process which increases the thickness for the coarse cell metallization features. Finally, reflective losses have been reduced by the application of a double layer anti-reflection (DLAR) coating. Another advantage of DLAR coating is that it will give further 3% higher current density than the SiO{sub 2} single layer anti-reflection (SLAR) coated cells when encapsulated into modules. The cells display a monochromatic light energy conversion efficiency of 46.3% for 1.04 {micro}m wavelength light, also the highest ever for a silicon device.

  16. EE580 Solar Cells Todd J. Kaiser

    E-print Network

    Kaiser, Todd J.

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

  17. Detailed balance analysis of nanophotonic solar cells

    E-print Network

    Fan, Shanhui

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

  18. EE580 Solar Cells Todd J. Kaiser

    E-print Network

    Kaiser, Todd J.

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

  19. Zinc transporter 7 is located in the cis-Golgi apparatus of mouse choroid epithelial cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The cellular localization of zinc transporter 7 protein in the mouse choroid plexus, an area on the ventricles of the brain where cerebrospinal fluid (CSF) is produced, was examined in this study. Zinc transporter 7 expressing cells were detected in the third, lateral, and fourth ventricles of the m...

  20. Determining adaptive and adverse oxidative stress responses in human bronical epithelial cells exposed to zinc

    EPA Science Inventory

    Determining adaptive and adverse oxidative stress responses in human bronchial epithelial cells exposed to zincJenna M. Currier1,2, Wan-Yun Cheng1, Rory Conolly1, Brian N. Chorley1Zinc is a ubiquitous contaminant of ambient air that presents an oxidant challenge to the human lung...

  1. The effects of zinc status on early growth in infants with sickle cell disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Growth failure, maturational delay, and alterations in body composition occur in older children and adults with Sickle Cell Disease (SCD). Poor nutritional status, specifically zinc deficiency, has been widely implicated, although infants with SCD have not been studied. We determined zinc status in ...

  2. Nanostructured Materials for Solar Cells

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

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

  3. A novel chlorophyll solar cell

    NASA Astrophysics Data System (ADS)

    Ludlow, J. C.

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

  4. Mixed ternary heterojunction solar cell

    DOEpatents

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

    1992-08-25

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

  5. Impurities in silicon solar cells

    NASA Technical Reports Server (NTRS)

    Davis, J. R., Jr.; Rohatgi, A.; Hopkins, R. H.; Blais, P. D.; Rai-Choudhury, P.; Mccormick, J. R.; Mollenkopf, H. C.

    1980-01-01

    The paper investigates the effects of metallic impurities on the performance of silicon solar cells. Czochralski and polycrystalline ingots were employed with boron and phosphorus as primary dopants and with controlled additions of secondary impurities. The data obtained from over 200 crystals indicate that impurity-induced performance loss is primarily due to a reduction of the base diffusion length. Based on this observation, a model is developed which predicts cell performance as a function of secondary impurity concentrations. The model calculations are in good agreement with experimental values except for Cu, Ni, Fe, and to a lesser degree, carbon, which at higher concentrations degrade the cell by junction defect mechanisms.

  6. Interfaces in perovskite solar cells.

    PubMed

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

    2015-06-01

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

  7. 22. 8% efficient silicon solar cell

    SciTech Connect

    Blakers, A.W.; Wang, A.; Milne, A.M.; Zhao, J.; Green, M.A. )

    1989-09-25

    A new silicon solar cell structure, the passivated emitter and rear cell, is described. The cell structure has yielded independently confirmed efficiencies of up to 22.8%, the highest ever reported for a silicon cell.

  8. Transparent conducting oxides (TCO's) for amorphous silicon solar cells

    NASA Astrophysics Data System (ADS)

    Hegedus, Steven; Liang, Haifan; Gordon, Roy G.

    1996-01-01

    The stability of various textured tin oxide and zinc oxide transparent conductors was evaluated against annealing in air, in vacuum or exposed to hydrogen plasma. Only fluorine-doped zinc oxide deposited by atmospheric pressure chemical vapor deposition (APCVD) had stable electrical and optical properties under all conditions. Thin layers of ZnO or TiO2 greatly improved the plasma resistance of SnO2. A new TCO material, niobium-doped titanium dioxide (TiO2:Nb) was able to withstand hydrogen plasmas with only slight increases in its optical absorption and conductivity. Composite TCO's consisting of glass/SnO2:F/TiO2:Nb were shown to provide good electrical contact to amorphous silicon solar cells.

  9. Advanced solar cell

    SciTech Connect

    Hingorani, N.G.; Mehta, H.

    1993-06-01

    A photovoltaic cell is described comprising: a layered extrinsic semiconductor having a substantially neutral base layer sandwiched between two heavily doped layers having opposite conductivity types to form a P-N junction within the semiconductor; and means for applying an externally generated electric field to the semiconductor to enhance a depletion region formed around the P-N junction to extend into the base layer when photo radiation impinges on the semiconductor.

  10. Crystal and electronic structures of CaAl 2Si 2-type rare-earth copper zinc phosphides RECuZnP 2 ( RE=Pr, Nd, Gd-Tm, Lu)

    NASA Astrophysics Data System (ADS)

    Blanchard, Peter E. R.; Stoyko, Stanislav S.; Cavell, Ronald G.; Mar, Arthur

    2011-01-01

    The quaternary rare-earth phosphides RECuZnP 2 ( RE=Pr, Nd, Gd-Tm, Lu) have been prepared by reaction of the elements at 900 °C, completing this versatile series which forms for nearly all RE metals. They adopt the trigonal CaAl 2Si 2-type structure (Pearson symbol hP5, space group P3¯ m1, Z=1), as confirmed by single-crystal X-ray diffraction analysis on ErCuZnP 2 and powder X-ray diffraction analysis on the remaining members. The Cu and Zn atoms are assumed to be disordered over the single transition-metal site. Band structure calculations on a hypothetically ordered YCuZnP 2 model suggest a semimetal, with a zero band gap between the valence and conduction bands. This electronic structure is supported by XPS valence band spectra for RECuZnP 2 ( RE=Gd-Er), in which the intensity drops off smoothly at the Fermi edge. The absence of a band gap permits the electron count to deviate from the precise value of 16 e - per formula unit, as demonstrated by the formation of a solid solution in GdCu xZn 2- xP 2 (1.0? x?1.3), while still retaining the CaAl 2Si 2-type structure. Because the Cu 2 p XPS spectra indicate that the Cu atoms are always monovalent, the substitution of Cu for Zn leads to a decrease in electron count and a lowering of the Fermi level in the valence band. The magnetic susceptibility of RECuZnP 2 ( RE=Gd-Er), which obeys the Curie-Weiss law, confirms the presence of trivalent RE atoms.

  11. Nanowire perovskite solar cell.

    PubMed

    Im, Jeong-Hyeok; Luo, Jingshan; Franckevi?ius, Marius; Pellet, Norman; Gao, Peng; Moehl, Thomas; Zakeeruddin, Shaik Mohammed; Nazeeruddin, Mohammad Khaja; Grätzel, Michael; Park, Nam-Gyu

    2015-03-11

    Organolead iodide perovskite, CH3NH3PbI3, was prepared in the form of nanowire by means of a small quantity of aprotic solvent in two-step spin-coating procedure. One-dimensional nanowire perovskite with the mean diameter of 100 nm showed faster carrier separation in the presence of hole transporting layer and higher lateral conductivity than the three-dimensional nanocuboid crystal. Reduction in dimensionality resulted in the hypsochromic shift of both absorption and fluorescence spectra, indicative of more localized exciton states in nanowires. The best performing device employing nanowire CH3NH3PbI3 delivered photocurrent density of 19.12 mA/cm(2), voltage of 1.052 V, and fill factor of 0.721, leading to a power conversion efficiency (PCE) of 14.71% at standard AM 1.5G solar illumination. A small I-V hysteresis was observed, where a PCE at forward scan was measured to be 85% of the PCE at reverse scan. PMID:25710268

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

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

  13. Towards stable silicon nanoarray hybrid solar cells

    PubMed Central

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

    2014-01-01

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

  14. GaAs Solar Cell Radiation Handbook

    NASA Technical Reports Server (NTRS)

    Anspaugh, B. E.

    1996-01-01

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

  15. Study of solar cell welds

    NASA Technical Reports Server (NTRS)

    Workman, G. L.

    1978-01-01

    The thermal imaging technique was evaluated for its capabilities in the nondestructive evaluation of solar cell welds. The temperature and spatial resolution of state of the art instrumentation was sufficient for both qualitative and quantitative determination of the quality of solar cell welds. The addition of color digitized thermography enhanced the aspects of the thermographic display and allowed easily computerized testing procedures. For automated testing systems an accurate correlation of weld quality with temperature profiles of the welds needs to be performed. In comparison, the holographic technique was complementary with the thermal imaging technique, except that the holographic analysis appeared to be more quantitative at the present time. However, the thermal imaging approach is much more versatile in overall capabilities.

  16. Interface engineering for efficient fullerene-free organic solar cells

    SciTech Connect

    Shivanna, Ravichandran; Narayan, K. S. E-mail: narayan@jncasr.ac.in; Rajaram, Sridhar E-mail: narayan@jncasr.ac.in

    2015-03-23

    We demonstrate the role of zinc oxide (ZnO) morphology and addition of an acceptor interlayer to achieve high efficiency fullerene-free bulk heterojunction inverted organic solar cells. Nanopatterning of the ZnO buffer layer enhances the effective light absorption in the active layer, and the insertion of a twisted perylene acceptor layer planarizes and decreases the electron extraction barrier. Along with an increase in current homogeneity, the reduced work function difference and selective transport of electrons prevent the accumulation of charges and decrease the electron-hole recombination at the interface. These factors enable an overall increase of efficiency to 4.6%, which is significant for a fullerene-free solution-processed organic solar cell.

  17. High Temperature Solar Cell Development

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

    The majority of satellites and near-earth probes developed to date have used photovoltaic arrays for power generation. If future mission to probe environments close to the sun will be able to use photovoltaic power, solar cells that can function at high temperatures, under high light intensity, and high radiation conditions must be developed. In this paper, we derive the optimum bandgap as a function of the operating temperature.

  18. Biocompatibility of a novel zinc stent with a closed-cell-design.

    PubMed

    Hiebl, Bernhard; Nennig, Ernst; Schiestel, Stefanie; Kovacs, Adalbert; Jung, Friedrich; Fischer, Harald

    2015-09-01

    Biomaterials made of zinc have been widely described to be antioxidative, hypothrombogenic, antiinflammatory and antiproliferative. Additionally in vivo zinc is toxic only in high concentrations and can completely be metabolized in vivo. Due to these properties zinc based vascular stents might be able to reduce the rate of restenosis in comparison to bare metal stents and zinc stents might be also able to limit the foreign body reaction. In the presented study we tested the biocompatibility and degradability of a stent made of zinc and characterized by a closed-cell-design to achieve high opening force and to increase stent stiffness. After 100 days of enzymatic and hydrolytic degradation in 15?ml blood serum (fetal calf serum) a significant loss of weight (1.72 wt% ) was measured. Zinc was compared to other metals in terms of degradation rates. After six weeks of incubation in physiologic sodium chloride solution zinc showed the slowest degradation time, 6 times less than stainless steel and 4 times less than magnesium. In the tests for cytotoxic effects the degraded zinc stent caused no changes in the LDH-release and cell membrane integrity (3T3 cells, mouse fibroblasts) respectively, in the cell activity/proliferation (MTS assay) and in the morphological characteristics of the cells and cell layers in comparison to the control material (polystyrene). Based on these results the tested zinc stent proved to be non-cytotoxic and to be characterized by degradation characteristics which might be advantageous in comparison to magnesium and stainless steel. PMID:26519227

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

    E-print Network

    Sibener, Steven

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

  20. Spectral sensitization of nanocrystalline solar cells

    DOEpatents

    Spitler, Mark T. (Concord, MA); Ehret, Anne (Malden, MA); Stuhl, Louis S. (Bedford, MA)

    2002-01-01

    This invention relates to dye sensitized polycrystalline photoelectrochemical solar cells for use in energy transduction from light to electricity. It concerns the utility of highly absorbing organic chromophores as sensitizers in such cells and the degree to which they may be utilized alone and in combination to produce an efficient photoelectrochemical cell, e.g., a regenerative solar cell.

  1. Recent Advances in Solar Cell Technology

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Bailey, Sheila G.; Piszczor, Michael F., Jr.

    1996-01-01

    The advances in solar cell efficiency, radiation tolerance, and cost over the last decade are reviewed. Potential performance of thin-film solar cells in space are discussed, and the cost and the historical trends in production capability of the photovoltaics industry are considered with respect to the requirements of space power systems. Concentrator cells with conversion efficiency over 30%, and nonconcentrating solar cells with efficiency over 25% are now available, and advanced radiation-tolerant cells and lightweight, thin-film arrays are both being developed. Nonsolar applications of solar cells, including thermophotovoltaics, alpha- and betavoltaics, and laser power receivers, are also discussed.

  2. Zip4 Mediated Zinc Influx Stimulates Insulin Secretion in Pancreatic Beta Cells

    PubMed Central

    Hardy, Alexandre B.; Prentice, Kacey J.; Froese, Sean; Liu, Ying; Andrews, Glen K.; Wheeler, Michael B.

    2015-01-01

    Zinc has an important role in normal pancreatic beta cell physiology as it regulates gene transcription, insulin crystallization and secretion, and cell survival. Nevertheless, little is known about how zinc is transported through the plasma membrane of beta cells and which of the class of zinc influx transporters (Zip) is involved. Zip4 was previously shown to be expressed in human and mouse beta cells; however, its function there is still unknown. Therefore, the aim of this study was to define the zinc transport role of Zip4 in beta cells. To investigate this, Zip4 was over-expressed in MIN6 beta cells using a pCMV6-Zip4GFP plasmid. Organelle staining combined with confocal microscopy showed that Zip4 exhibits a widespread localization in MIN6 cells. Time-lapse zinc imaging experiments showed that Zip4 increases cytoplasmic zinc levels. This resulted in increased granular zinc content and glucose-stimulated insulin secretion. Interestingly, it is unlikely that the increased glucose stimulated insulin secretion was triggered by a modulation of mitochondrial function, as mitochondrial membrane potential remained unchanged. To define the role of Zip4 in-vivo, we generated a beta cell-specific knockout mouse model (Zip4BKO). Deletion of the Zip4 gene was confirmed in Zip4BKO islets by PCR, RT-PCR, and immuno-histochemistry. Zip4BKO mice showed slightly improved glucose homeostasis but no change in insulin secretion during an oral glucose tolerance test. While Zip4 was not found to be essential for proper glucose homeostasis and insulin secretion in vivo in mice, this study also found that Zip4 mediates increases in cytoplasmic and granular zinc pools and stimulates glucose dependant insulin secretion in-vitro. PMID:25806541

  3. Silicon Carbide Solar Cells Investigated

    NASA Technical Reports Server (NTRS)

    Bailey, Sheila G.; Raffaelle, Ryne P.

    2001-01-01

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

  4. Optimization of transparent and reflecting electrodes for amorphous silicon solar cells. Annual subcontract report, April 1, 1994--March 31, 1995

    SciTech Connect

    Gordon, R.G.

    1995-10-01

    Transparent and reflecting electrodes are important parts of the structure of amorphous silicon solar cells. We report improved methods for depositing zinc oxide, deposition of tin nitride as a potential reflection-enhancing diffusion barrier between the a-Si and back metal electrodes. Highly conductive and transparent fluorine-doped zinc oxide was successfully produced on small areas by atmospheric pressure CVD from a less hazardous zinc precursor, zinc acetylacetonate. The optical properties measured for tin nitride showed that the back-reflection would be decreased if tin nitride were used instead of zinc oxide as a barrier layer over silver on aluminum. Niobium-doped titanium dioxide was produced with high enough electrical conductivity so that normal voltages and fill factors were obtained for a-Si cells made on it.

  5. Extended Temperature Solar Cell Technology Development

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Jenkins, Phillip; Scheiman, David; Rafaelle, Ryne

    2004-01-01

    Future NASA missions will require solar cells to operate both in regimes closer to the sun, and farther from the sun, where the operating temperatures will be higher and lower than standard operational conditions. NASA Glenn is engaged in testing solar cells under extended temperature ranges, developing theoretical models of cell operation as a function of temperature, and in developing technology for improving the performance of solar cells for both high and low temperature operation.

  6. Analyzing free zinc(II) ion concentrations in cell biology with fluorescent chelating molecules.

    PubMed

    Maret, Wolfgang

    2015-02-01

    Essential metal ions are tightly controlled in biological systems. An understanding of metal metabolism and homeostasis is being developed from quantitative information of the sizes, concentrations, and dynamics of cellular and subcellular metal ion pools. In the case of human zinc metabolism, minimally 24 proteins of two zinc transporter families and a dozen metallothioneins participate in cellular uptake, extrusion, and re-distribution among cellular compartments. Significantly, zinc(ii) ions are now considered signaling ions in intra- and intercellular communication. Such functions require transients of free zinc ions. It is experimentally quite challenging to distinguish zinc that is protein-bound from zinc that is not bound to proteins. Measurement of total zinc is relatively straightforward with analytical techniques such as atomic absorption/emission spectroscopy or inductively coupled plasma mass spectrometry. Total zinc concentrations of human cells are 200-300 ?M. In contrast, the pool of non-protein bound zinc is mostly examined with fluorescence microscopy/spectroscopy. There are two widely applied fluorescence approaches, one employing low molecular weight chelating agents ("probes") and the other metal-binding proteins ("sensors"). The protein sensors, such as the CALWY, Zap/ZifCY, and carbonic anhydrase-based sensors, can be genetically encoded and have certain advantages in terms of controlling intracellular concentration, localization, and calibration. When employed correctly, both probes and sensors can establish qualitative differences in free zinc ion concentrations. However, when quantitative information is sought, the assumptions underlying the applications of probes and sensors must be carefully examined and even then measured pools of free zinc ions remain methodologically defined. A consensus is building that the steady-state free zinc ion concentrations in the cytosol are in the picomolar range but there is no consensus on their concentrations in subcellular compartments. Applying the extensive toolbox of available probes/sensors in biological systems requires an understanding of the principles of cellular zinc homeostasis and the chemical biology of the probes and sensors. Regardless of limitations in specificity (for a particular metal ion), selectivity (for a particular metal pool), and sensitivity (detection limit), the technology is making remarkable contributions to imaging zinc with high spatiotemporal resolution in single cells and to defining the biochemical functions of zinc ions in cellular regulation. PMID:25362967

  7. Method of making encapsulated solar cell modules

    NASA Technical Reports Server (NTRS)

    Anagnostou, E.; Forestieri, A. F. (inventors)

    1978-01-01

    Electrical connections to solar cells in a module are made at the same time the cells are encapsulated for protection. The encapsulating material is embossed to facilitate the positioning of the cells during assembly.

  8. Eutectic Contact Inks for Solar Cells

    NASA Technical Reports Server (NTRS)

    Ross, B.

    1985-01-01

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

  9. Boron phosphide under pressure: In situ study by Raman scattering and X-ray diffraction

    SciTech Connect

    Solozhenko, Vladimir L.; Kurakevych, Oleksandr O.; Le Godec, Yann; Kurnosov, Aleksandr V.; Oganov, Artem R.

    2014-07-21

    Cubic boron phosphide, BP, has been studied in situ by X-ray diffraction and Raman scattering up to 55?GPa at 300?K in a diamond anvil cell. The bulk modulus of B{sub 0}?=?174(2) GPa has been established, which is in excellent agreement with our ab initio calculations. The data on Raman shift as a function of pressure, combined with equation-of-state (EOS) data, allowed us to estimate the Grüneisen parameters of the TO and LO modes of zinc-blende structure, ?{sub G}{sup TO?}=?1.26 and ?{sub G}{sup LO?}=?1.13, just like in the case of other A{sup III}B{sup V} diamond-like phases, for which ?{sub G}{sup TO?}>??{sub G}{sup LO?}??1. We also established that the pressure dependence of the effective electro-optical constant ? is responsible for a strong change in relative intensities of the TO and LO modes from I{sub TO}/I{sub LO}???0.25 at 0.1?MPa to I{sub TO}/I{sub LO}???2.5 at 45?GPa, for which we also find excellent agreement between experiment and theory.

  10. Zinc(II)-Coordinated Oligotyrosine: A New Class of Cell Penetrating James R. Johnson, Hua Jiang, and Bradley D. Smith*

    E-print Network

    Smith, Bradley D.

    Zinc(II)-Coordinated Oligotyrosine: A New Class of Cell Penetrating Peptide James R. Johnson, Hua with a zinc (II) cation. This in turn allows reversible association with a chelating oxyanion- lylamine unit that forms a stable coordination complex with a zinc (II) cation (Scheme 1) (25). Previously

  11. Anti-inflammatory effects of zinc in PMA-treated human gingival fibroblast cells

    PubMed Central

    Kim, Sangwoo; Jeon, Sangmi; Hui, Zheng; Kim, Young; Im, Yeonggwan; Lim, Wonbong; Kim, Changsu; Choi, Hongran; Kim, Okjoon

    2015-01-01

    Objectives: Abnormal cellular immune response has been considered to be responsible for oral lesions in recurrent aphthous stomatitis. Zinc has been known to be an essential nutrient metal that is necessary for a broad range of biological activities including antioxidant, immune mediator, and anti-inflammatory drugs in oral mucosal disease. The objective of this study was to investigate the effects of zinc in a phorbol-12-myristate-13-acetate (PMA)-treated inflammatory model on human gingival fibroblast cells (hGFs). Study Design: Cells were pre-treated with zinc chloride, followed by PMA in hGFs. The effects were assessed on cell viability, cyclooxygenease-1,2(COX-1/2) protein expression, PGE2 release, ROS production and cytokine release, Results: The effects were assessed on cell viability, COX1/2 protein expression, PGE2 release, ROS production, cytokine release. The results showed that, in the presence of PMA, zinc treatment leads to reduce the production of ROS, which results in decrease of COX-2 expression and PGE2 release. Conclusions: Thus, we suggest that zinc treatment leads to the mitigation of oral inflammation and may prove to be an alternative treatment for recurrent aphthous stomatitis. Key words:Zinc, inflammatory response, cytokines, phorbol-12-myristate-13-acetate, gingival fibroblasts cells. PMID:25662537

  12. Ethambutol-induced toxicity is mediated by zinc and lysosomal membrane permeabilization in cultured retinal cells

    SciTech Connect

    Chung, Hyewon; Yoon, Young Hee; Hwang, Jung Jin; Cho, Kyung Sook; Koh, Jae Young; Kim, June-Gone

    2009-03-01

    Ethambutol, an efficacious antituberculosis agent, can cause irreversible visual loss in a small but significant fraction of patients. However, the mechanism of ocular toxicity remains to be established. We previously reported that ethambutol caused severe vacuole formation in cultured retinal cells, and that the addition of zinc along with ethambutol aggravated vacuole formation whereas addition of the cell-permeable zinc chelator, N,N,N',N'-tetrakis (2-pyridylmethyl) ethylenediamine (TPEN), reduced vacuole formation. To investigate the origin of vacuoles and to obtain an understanding of drug toxicity, we used cultured primary retinal cells from newborn Sprague-Dawley rats and imaged ethambutol-treated cells stained with FluoZin-3, zinc-specific fluorescent dye, under a confocal microscope. Almost all ethambutol-induced vacuoles contained high levels of labile zinc. Double staining with LysoTracker or MitoTracker revealed that almost all zinc-containing vacuoles were lysosomes and not mitochondria. Intracellular zinc chelation with TPEN markedly blocked both vacuole formation and zinc accumulation in the vacuole. Immunocytochemistry with antibodies to lysosomal-associated membrane protein-2 (LAMP-2) and cathepsin D, an acid lysosomal hydrolase, disclosed lysosomal activation after exposure to ethambutol. Immunoblotting after 12 h exposure to ethambutol showed that cathepsin D was released into the cytosol. In addition, cathepsin inhibitors attenuated retinal cell toxicity induced by ethambutol. This is consistent with characteristics of lysosomal membrane permeabilization (LMP). TPEN also inhibited both lysosomal activation and LMP. Thus, accumulation of zinc in lysosomes, and eventual LMP, may be a key mechanism of ethambutol-induced retinal cell death.

  13. Heat-sterilized silver oxide-zinc cells: Cycle life studies

    NASA Technical Reports Server (NTRS)

    Arms, J. T.

    1973-01-01

    A JPL study was conducted to evaluate the cell design parameters that contribute to the cycle life of sealed, heat-sterilized silver oxide-zinc cells. Test cells having a rated capacity of 4.2 A-h were fabricated using zinc oxide electrodes prepared by the sintered Teflon process. Two separator variations were evaluated, one having acrylic acid and the other methacrylic acid grafted to irradiated polyethylene film. Significant results of this study include the following: (1) cycle life in excess of 300 cycles was attained; (2) a zinc oxide/silver stoichiometric ratio of 1.5 resulted in greater cycle life than a ratio of 1.1, and similar cycle life to cells having a ratio of 2; (3) cells having methacrylic acid grafted separators suffered somewhat less in capacity loss due to zinc electrode shape change than cells having acrylic acid type; (4) use of acrylic acid grafted separators was slightly superior to the methacrylic acid type in respect to silver penetration; and (5) the inclusion of a layer of potassium titanate paper adjacent to the zinc electrodes resulted in cells that achieved higher cycle life before any of the group failed than that reached by cells of any other construction.

  14. Search for new solar cell heats up

    SciTech Connect

    Lipkin, R.

    1990-11-05

    Researchers are in the process of developing an organic solar energy cell with a plasticlike material that simplifies the complicated process of creating a working cell - one that is cheap, easy to produce and has a variety of potential applications. The chemical is polyacetylene and can be painted on anything to become a solar cell.

  15. Plasmonic silicon solar cells: impact of material quality and geometry.

    PubMed

    Pahud, Celine; Isabella, Olindo; Naqavi, Ali; Haug, Franz-Josef; Zeman, Miro; Herzig, Hans Peter; Ballif, Christophe

    2013-09-01

    We study n-i-p amorphous silicon solar cells with light-scattering nanoparticles in the back reflector. In one configuration, the particles are fully embedded in the zinc oxide buffer layer; In a second configuration, the particles are placed between the buffer layer and the flat back electrode. We use stencil lithography to produce the same periodic arrangement of the particles and we use the same solar cell structure on top, thus establishing a fair comparison between a novel plasmonic concept and its more traditional counterpart. Both approaches show strong resonances around 700 nm in the external quantum efficiency the position and intensity of which vary strongly with the nanoparticle shape. Moreover, disagreement between simulations and our experimental results suggests that the dielectric data of bulk silver do not correctly represent the reality. A better fit is obtained by introducing a porous interfacial layer between the silver and zinc oxide. Without the interfacial layer, e.g. by improved processing of the nanoparticles, our simulations show that the nanoparticles concept could outperform traditional back reflectors. PMID:24104574

  16. Monolithic and mechanical multijunction space solar cells

    NASA Technical Reports Server (NTRS)

    Jain, Raj K.; Flood, Dennis J.

    1992-01-01

    High-efficiency, lightweight, radiation-resistant solar cells are essential to meet the large power requirements of future space missions. Single-junction cells are limited in efficiency. Higher cell efficiencies could be realized by developing multijunction, multibandgap solar cells. Monolithic and mechanically stacked tandem solar cells surpassing single-junction cell efficiencies have been fabricated. This article surveys the current status of monolithic and mechanically stacked multibandgap space solar cells, and outlines problems yet to be resolved. The monolithic and mechanically stacked cells each have their own problems related to size, processing, current and voltage matching, weight, and other factors. More information is needed on the effect of temperature and radiation on the cell performance. Proper reference cells and full-spectrum range simulators are also needed to measure efficiencies correctly. Cost issues are not addressed, since the two approaches are still in the developmental stage.

  17. Improved monolithic tandem solar cell

    SciTech Connect

    Wanlass, M.W.

    1991-04-23

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

  18. Bypass diode for a solar cell

    DOEpatents

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

    2012-03-13

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

  19. Solar Cell Modules With Improved Backskin

    DOEpatents

    Gonsiorawski, Ronald C. (Danvers, MA)

    2003-12-09

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

  20. Zinc regulates iNOS-derived nitric oxide formation in endothelial cells

    PubMed Central

    Cortese-Krott, Miriam M.; Kulakov, Larissa; Opländer, Christian; Kolb-Bachofen, Victoria; Kröncke, Klaus-D.; Suschek, Christoph V.

    2014-01-01

    Aberrant production of nitric oxide (NO) by inducible NO synthase (iNOS) has been implicated in the pathogenesis of endothelial dysfunction and vascular disease. Mechanisms responsible for the fine-tuning of iNOS activity in inflammation are still not fully understood. Zinc is an important structural element of NOS enzymes and is known to inhibit its catalytical activity. In this study we aimed to investigate the effects of zinc on iNOS activity and expression in endothelial cells. We found that zinc down-regulated the expression of iNOS (mRNA+protein) and decreased cytokine-mediated activation of the iNOS promoter. Zinc-mediated regulation of iNOS expression was due to inhibition of NF-?B transactivation activity, as determined by a decrease in both NF-?B-driven luciferase reporter activity and expression of NF-?B target genes, including cyclooxygenase 2 and IL-1?. However, zinc did not affect NF-?B translocation into the nucleus, as assessed by Western blot analysis of nuclear and cytoplasmic fractions. Taken together our results demonstrate that zinc limits iNOS-derived high output NO production in endothelial cells by inhibiting NF-?B-dependent iNOS expression, pointing to a role of zinc as a regulator of iNOS activity in inflammation. PMID:25180171

  1. Nanomolar concentrations of zinc pyrithione increase cell susceptibility to oxidative stress induced by hydrogen peroxide in rat thymocytes.

    PubMed

    Oyama, Tomohiro M; Saito, Minoru; Yonezawa, Takayasu; Okano, Yoshiro; Oyama, Yasuo

    2012-06-01

    Zinc pyrithione is used as an antifouling agent. However, the environmental impacts of zinc pyrithione have recently been of concern. Zinc induces diverse actions during oxidative stress; therefore, we examined the effect of zinc pyrithione on rat thymocytes suffering from oxidative stress using appropriate fluorescent probes. The cytotoxicity of zinc pyrithione was not observed when the cells were incubated with 3 ?M zinc pyrithione for 3 h. However, zinc pyrithione at nanomolar concentrations (10 nM or more) significantly increased the lethality of cells suffering from oxidative stress induced by 3 mM H(2)O(2). The application of zinc pyrithione alone at nanomolar concentrations increased intracellular Zn(2+) level and the cellular content of superoxide anions, and decreased the cellular content of nonprotein thiols. The simultaneous application of nanomolar zinc pyrithione and micromolar H(2)O(2) synergistically increased the intracellular Zn(2+) level. Therefore, zinc pyrithione at nanomolar concentrations may exert severe cytotoxic action on cells simultaneously exposed to chemicals that induce oxidative stress. If so, zinc pyrithione leaked from antifouling materials into surrounding environments would be a risk factor for aquatic ecosystems. Alternatively, zinc pyrithione under conditions of oxidative stress may become more potent antifouling ingredient. PMID:22356860

  2. Current and lattice matched tandem solar cell

    DOEpatents

    Olson, Jerry M. (Lakewood, CO)

    1987-01-01

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

  3. Laser-assisted solar cell metallization processing

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

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

  4. Very High Efficiency Solar Cell Modules

    SciTech Connect

    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

    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.

  5. Enhanced Gadd45 expression and delayed G2/M progression are p53 dependent in zinc-supplemented human bronchial epithelial cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zinc is an essential nutrient for humans; however, this study demonstrated for the first time that an elevated zinc status, created by culturing cells at optimal plasma zinc concentration attainable by oral zinc supplementation, is cytotoxic for normal human bronchial epithelial (NHBE) cells. p53 p...

  6. Front contact solar cell with formed emitter

    DOEpatents

    Cousins, Peter John (Menlo Park, CA)

    2012-07-17

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

  7. Front contact solar cell with formed emitter

    DOEpatents

    Cousins, Peter John

    2014-11-04

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

  8. A zinc-resistant human epithelial cell line is impaired in cadmium and manganese import

    SciTech Connect

    Rousselet, Estelle |; Richaud, Pierre ||; Douki, Thierry; Chantegrel, Jocelyne Garcia; Favier, Alain |||; Moulis, Jean-Marc ||

    2008-08-01

    A human epithelial cell line (HZR) growing with high zinc concentrations has been analyzed for its ability to sustain high cadmium concentrations. Exposure to up to 200 {mu}M of cadmium acetate for 24 h hardly impacted viability, whereas most of parental HeLa cells were killed by less than 10 {mu}M of cadmium. Upon challenge by 35 fold higher cadmium concentrations than HeLa cells, HZR cells did not display increased DNA damage, increased protein oxidation, or changed intracellular cadmium localization. Rather, the main cause of resistance against cadmium was by avoiding cadmium entry into cells, which differs from that against zinc as the latter accumulates inside cells. The zinc-resistant phenotype of these cells was shown to also impair extracellular manganese uptake. Manganese and cadmium competed for entry into HeLa cells. Probing formerly identified cadmium or manganese transport systems in different animal cells did not evidence any significant change between HeLa and HZR cells. These results reveal zinc adaptation influences manganese and cadmium cellular traffic and they highlight previously unknown connections among homeostasis of divalent metals.

  9. Influence of zinc deficiency on AKT-MDM2-P53 signaling axes in normal and malignant human prostate cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With prostate being the highest zinc-accumulating tissue before the onset of cancer, the effects of physiologic levels of zinc on Akt-Mdm2-p53 and Akt-p21 signaling axes in human normal prostate epithelial cells (PrEC) and malignant prostate LNCaP cells were examined. Cells were cultured for 6 d in...

  10. Disulfiram-induced cytotoxicity and endo-lysosomal sequestration of zinc in breast cancer cells

    PubMed Central

    Wiggins, Helen L.; Wymant, Jennifer M.; Solfa, Francesca; Hiscox, Stephen E.; Taylor, Kathryn M.; Westwell, Andrew D.; Jones, Arwyn T.

    2015-01-01

    Disulfiram, a clinically used alcohol-deterrent has gained prominence as a potential anti-cancer agent due to its impact on copper-dependent processes. Few studies have investigated zinc effects on disulfiram action, despite it having high affinity for this metal. Here we studied the cytotoxic effects of disulfiram in breast cancer cells, and its relationship with both intra and extracellular zinc. MCF-7 and BT474 cancer cell lines gave a striking time-dependent biphasic cytotoxic response between 0.01 and 10 ?M disulfiram. Co-incubation of disulfiram with low-level zinc removed this effect, suggesting that availability of extracellular zinc significantly influences disulfiram efficacy. Live-cell confocal microscopy using fluorescent endocytic probes and the zinc dye Fluozin-3 revealed that disulfiram selectively and rapidly increased zinc levels in endo-lysosomes. Disulfiram also caused spatial disorganization of late endosomes and lysosomes, suggesting they are novel targets for this drug. This relationship between disulfiram toxicity and ionophore activity was consolidated via synthesis of a new disulfiram analog and overall we demonstrate a novel mechanism of disulfiram-cytotoxicity with significant clinical implications for future use as a cancer therapeutic. PMID:25557293

  11. Disulfiram-induced cytotoxicity and endo-lysosomal sequestration of zinc in breast cancer cells.

    PubMed

    Wiggins, Helen L; Wymant, Jennifer M; Solfa, Francesca; Hiscox, Stephen E; Taylor, Kathryn M; Westwell, Andrew D; Jones, Arwyn T

    2015-02-01

    Disulfiram, a clinically used alcohol-deterrent has gained prominence as a potential anti-cancer agent due to its impact on copper-dependent processes. Few studies have investigated zinc effects on disulfiram action, despite it having high affinity for this metal. Here we studied the cytotoxic effects of disulfiram in breast cancer cells, and its relationship with both intra and extracellular zinc. MCF-7 and BT474 cancer cell lines gave a striking time-dependent biphasic cytotoxic response between 0.01 and 10 ?M disulfiram. Co-incubation of disulfiram with low-level zinc removed this effect, suggesting that availability of extracellular zinc significantly influences disulfiram efficacy. Live-cell confocal microscopy using fluorescent endocytic probes and the zinc dye Fluozin-3 revealed that disulfiram selectively and rapidly increased zinc levels in endo-lysosomes. Disulfiram also caused spatial disorganization of late endosomes and lysosomes, suggesting they are novel targets for this drug. This relationship between disulfiram toxicity and ionophore activity was consolidated via synthesis of a new disulfiram analog and overall we demonstrate a novel mechanism of disulfiram-cytotoxicity with significant clinical implications for future use as a cancer therapeutic. PMID:25557293

  12. Method for processing silicon solar cells

    DOEpatents

    Tsuo, Y.S.; Landry, M.D.; Pitts, J.R.

    1997-05-06

    The instant invention teaches a novel method for fabricating silicon solar cells utilizing concentrated solar radiation. The solar radiation is concentrated by use of a solar furnace which is used to form a front surface junction and back-surface field in one processing step. The present invention also provides a method of making multicrystalline silicon from amorphous silicon. The invention also teaches a method of texturing the surface of a wafer by forming a porous silicon layer on the surface of a silicon substrate and a method of gettering impurities. Also contemplated by the invention are methods of surface passivation, forming novel solar cell structures, and hydrogen passivation. 2 figs.

  13. Method for processing silicon solar cells

    DOEpatents

    Tsuo, Y. Simon (Golden, CO); Landry, Marc D. (Lafayette, CO); Pitts, John R. (Lakewood, CO)

    1997-01-01

    The instant invention teaches a novel method for fabricating silicon solar cells utilizing concentrated solar radiation. The solar radiation is concentrated by use of a solar furnace which is used to form a front surface junction and back-surface field in one processing step. The present invention also provides a method of making multicrystallline silicon from amorphous silicon. The invention also teaches a method of texturing the surface of a wafer by forming a porous silicon layer on the surface of a silicon substrate and a method of gettering impurities. Also contemplated by the invention are methods of surface passivation, forming novel solar cell structures, and hydrogen passivation.

  14. Monolithic cascade-type solar cells

    SciTech Connect

    Yamamoto, S.; Shibukawa, A.; Yamaguchi, M.

    1985-12-01

    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 an n(+)-type GaAs base, a GaInAs bottom solar cell, and a GaAiInAs top solar cell. The surface of the cell is coated with a SiO antireflection film. The efficiency of the cell is 32%.

  15. Epitaxial silicon growth for solar cells

    NASA Technical Reports Server (NTRS)

    Daiello, R. V.; Robinson, P. H.; Richman, D.

    1978-01-01

    Growth and fabrication procedures for the baseline solar cells are described along with measured cell parameters, and the results. Reproducibility of these results was established and the direction to be taken for higher efficiency is identified.

  16. Monolithic cells for solar fuels.

    PubMed

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

    2014-12-01

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

  17. Loss of pluripotency in human embryonic stem cells directly correlates with an increase in nuclear zinc.

    SciTech Connect

    Finney, L.; Vogt, S.; Wolford, J. L.; Chishti, Y.; Jin, Q.; Ward, J.; Chen, L.

    2010-01-01

    The pluripotency of human embryonic stem cells (hESCs) is important to investigations of early development and to cell replacement therapy, but the mechanism behind pluripotency is incompletely understood. Zinc has been shown to play a key role in differentiation of non-pluripotent cell types, but here its role in hESCs is directly examined. By mapping the distribution of metals in hESCs at high resolution by x-ray fluorescence microprobe (XFM) and by analyzing subcellular metal content, we have found evidence that loss of pluripotency is directly correlated with an increase in nuclear zinc. Zinc elevation not only redefines our understanding of the mechanisms that support pluripotency, but also may act as a biomarker and an intervention point for stem cell differentiation.

  18. Zinc supplementation induces apoptosis and enhances antitumor efficacy of docetaxel in non-small-cell lung cancer

    PubMed Central

    Kocdor, Hilal; Ates, Halil; Aydin, Suleyman; Cehreli, Ruksan; Soyarat, Firat; Kemanli, Pinar; Harmanci, Duygu; Cengiz, Hakan; Kocdor, Mehmet Ali

    2015-01-01

    Background Exposure to exogenous zinc results in increased apoptosis, growth inhibition, and altered oxidative stress in cancer cells. Previous studies also suggested that zinc sensitizes some cancer cells to cytotoxic agents depending on the p53 status. Therefore, zinc supplementation may show anticancer efficacy solely and may increase docetaxel-induced cytotoxicity in non-small-cell lung cancer cells. Methods Here, we report the effects of several concentrations of zinc combined with docetaxel on p53-wild-type (A549) and p53-null (H1299) cells. We evaluated cellular viability, apoptosis, and cell cycle progression as well as oxidative stress parameters, including superoxide dismutase, glutathione peroxidase, and malondialdehyde levels. Results Zinc reduced the viability of A549 cells and increased the apoptotic response in both cell lines in a dose-dependent manner. Zinc also amplified the docetaxel effects and reduced its inhibitory concentration 50 (IC50) values. The superoxide dismutase levels increased in all treatment groups; however, glutathione peroxidase was slightly increased in the combination treatments. Zinc also caused malondialdehyde elevations at 50 ?M and 100 ?M. Conclusion Zinc has anticancer efficacy against non-small-cell lung cancer cells in the presence of functionally active p53 and enhances docetaxel efficacy in both p53-wild-type and p53-deficient cancer cells. PMID:26251569

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

    PubMed

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

    2015-07-16

    Perovskite solar cells with transparent contacts may be used to compensate for thermalization losses of silicon solar cells in tandem devices. This offers a way to outreach stagnating efficiencies. However, perovskite top cells in tandem structures require contact layers with high electrical conductivity and optimal transparency. We address this challenge by implementing large-area graphene grown by chemical vapor deposition as a highly transparent electrode in perovskite solar cells, leading to identical charge collection efficiencies. Electrical performance of solar cells with a graphene-based contact reached those of solar cells with standard gold contacts. The optical transmission by far exceeds that of reference devices and amounts to 64.3% below the perovskite band gap. Finally, we demonstrate a four-terminal tandem device combining a high band gap graphene-contacted perovskite top solar cell (Eg = 1.6 eV) with an amorphous/crystalline silicon bottom solar cell (Eg = 1.12 eV). PMID:26266857

  20. Organic Tandem Solar Cells: Design and Formation

    NASA Astrophysics Data System (ADS)

    Chen, Chun-Chao

    In the past decade, research on organic solar cells has gone through an important development stage leading to major enhancements in power conversion efficiency, from 4% to 9% in single-junction devices. During this period, there are many novel processing techniques and device designs that have been proposed and adapted in organic solar-cell devices. One well-known device architecture that helps maximize the solar cell efficiency is the multi-junction tandem solar-cell design. Given this design, multiple photoactive absorbers as subcells are stacked in a monolithic fashion and assembled via series connection into one complete device, known as the tandem solar cell. Since multiple absorbers with different optical energy bandgaps are being applied in one tandem solar-cell device, the corresponding solar cell efficiency is maximized through expanded absorption spectrum and reduced carrier thermalization loss. In Chapter 3, the architecture of solution-processible, visibly transparent solar cells is introduced. Unlike conventional organic solar-cell devices with opaque electrodes (such as silver, aluminum, gold and etc.), the semi-transparent solar cells rely on highly transparent electrodes and visibly transparent photoactive absorbers. Given these two criteria, we first demonstrated the visibly transparent single-junction solar cells via the polymer absorber with near-infrared absorption and the top electrode based on solution-processible silver nanowire conductor. The highest visible transparency (400 ˜ 700 nm) of 65% was achieved for the complete device structure. More importantly, power conversion efficiency of 4% was also demonstrated. In Chapter 4, we stacked two semi-transparent photoactive absorbers in the tandem architecture in order to realize the semi-transparent tandem solar cells. A noticeable performance improvement from 4% to 7% was observed. More importantly, we modified the interconnecting layers with the incorporation of a thin conjugated polyelectrolyte layer functioning as the surface dipole formation layer to provide better electrical contact with the photoactive layer. Due to the effectiveness of the conjugated polyelectrolyte layer, performance improvement was also observed. Furthermore, other issues regarding the semi-transparent tandem solar cells (e.g., photocurrent matching, exterior color tuning, and transparency tuning) are all explored to optimize best performance. In Chapter 5 and 6, the architectures of double- and triple-junction tandem solar cells are explored. Theoretically, triple-junction tandem solar cells with three photoactive absorbers with cascaded energy bandgaps have the potential to achieve higher performance, in comparison with double-junction tandem solar cells. Such expectations can be ascribed to the minimized carrier thermalization loss and further improved light absorption. However, the design of triple-junction solar cells often involves sophisticated multiple layer deposition as well as substantial optimization. Therefore, there is a lack of successful demonstrations of triple-junction solar cells outperforming the double-junction counterparts. To solve the incompatible issues related to the layer deposition in the fabrication, we proposed a novel architecture of inverted-structure tandem solar cells with newly designed interconnecting layers. Our design of interconnecting layers does not only focus on maintaining the orthogonal solution processing advantages, but also provides an excellent compatibility in the energy level alignment to allow different absorber materials to be used. Furthermore, we also explored the light management inside the double- and triple-junction tandem solar cells. The study of light management was carried out through optical simulation method based transfer matrix formalism. The intention is to obtain a balanced photocurrent output from each subcells inside the tandem solar cell, thus the minimal recombination loss at the contact of interconnecting layers and the optimal efficiency can be expected. With help from simulations, we were able to ca

  1. Solar power satellites - Heat engine or solar cells

    NASA Technical Reports Server (NTRS)

    Oman, H.; Gregory, D. L.

    1978-01-01

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

  2. Inverted Organic Photovoltaic Cells with Solution-Processed Zinc Oxide as Electron Collecting Layer

    NASA Astrophysics Data System (ADS)

    Zhang, Chunfu; You, Hailong; Lin, Zhenhua; Hao, Yue

    2011-08-01

    In this work, inverted polymer:fullerene organic photovoltaic (OPV) cells with solution-processed zinc oxide (ZnO) as the electron collecting layer are investigated. ZnO films are prepared simply by the spin-casting of a zinc acetate dehydrate precursor solution, followed by sintering under ambient conditions. The performance of the fabricated inverted OPV cells shows a clear dependence on precursor concentration and sintering conditions. With the ZnO film derived from a sol-gel concentration of 0.1 M and sintered at 350 °C for 10 min, the inverted OPV cell shows optimum performance.

  3. A study of rechargeable zinc electrodes for alkaline cells requiring anodic limitation

    NASA Astrophysics Data System (ADS)

    Binder, L.; Odar, W.; Kordesch, K.

    1981-07-01

    Problems associated with the cyclic operation of zinc electrodes in rechargeable alkaline cells for which anodic limitation is required are investigated. Experiments were conducted to determine the influence of electrolyte additives and cell construction on the capacity loss of limited zinc electrodes during cycling; current-voltage diagrams for zinc electrodes within the potential range of passivation and of hydrogen evolution were also recorded. In tests of alkaline cells with zinc and MnO2 electrodes, it is found that the addition of ZnO and Zn(CN)2 to the electrolyte or the use of Zn(CN)2 for the electrode gel leads to an increase in cell cycle life up to 70 cycles. Cells with copper powder and PTFE added to the electrode gel are observed to exhibit nearly uniform cycles after a rapid drop in capacity at the second cycle. Passivation studies based on the current-voltage diagrams reveal a peak in current densities needed for passivation at an electrolyte concentration of 7.5 m KOH. Results also confirm the fact that metals including lead, tin and indium increase the hydrogen overvoltage of zinc to the same extent as mercury.

  4. Coupling of Luminescent Solar Concentrators to Plasmonic Solar Cells

    NASA Astrophysics Data System (ADS)

    Wang, Shu-Yi

    To make inexpensive solar cells is a continuous goal for solar photovoltaic (PV) energy industry. Thin film solar cells of various materials have been developed and continue to emerge in order to replace bulk silicon solar cells. A thin film solar cell not only uses less material but also requires a less expensive refinery process. In addition, other advantages coming along with small thickness are higher open circuit voltage and higher conversion efficiency. However, thin film solar cells, especially those made of silicon, have significant optical losses. In order to address this problem, this thesis investigates the spectral coupling of thin films PV to luminescent solar concentrators (LSC). LSC are passive devices, consisting of plastic sheets embedded with fluorescent dyes which absorb part of the incoming radiation spectrum and emit at specific wavelength. The emitted light is concentrated by total internal reflection to the edge of the sheet, where the PVs are placed. Since the light emitted from the LSC edge is usually in a narrow spectral range, it is possible to employ diverse strategies to enhance PV absorption at the peak of the emission wavelength. Employing plasmonic nanostructures has been shown to enhance absorption of thin films via forward scattering, diffraction and localized surface plasmon. These two strategies are theoretically investigated here for improving the absorption and elevating the output power of a thin film solar cell. First, the idea of spectral coupling of luminescent solar concentrators to plasmonic solar cells is introduced to assess its potential for increasing the power output. This study is carried out employing P3HT/PC60BM organic solar cells and LSC with Lumogen Red dyes. A simplified spectral coupling analysis is employed to predict the power density, considering the output spectrum of the LSC equivalent to the emission spectrum of the dye and neglecting any angular dependence. Plasmonic tuning is conducted to enhance absorption at the emission peak of the dye. A factorial increase in the output power density of coupled PV as compared to PV exposed directly to solar spectrum is observed for high light concentration on the edge. These initial results motivated a more in-depth study of coupled LSC-PV system, which took into account the radiative transport inside the realistic LSC. These investigations were carried out on LSCs using Lumogen Red305 and Rhodamine 6G dyes coupled to pristine and plasmonic ultra-thin film silicon solar cells. Prediction based on detailed balance shows that the coupled LSC-plasmonic solar cell can generate 63.7 mW/cm2 with a photocurrent density of 71.3 mA/cm2 which is higher than that of cSi solar cells available on current market. The second part of the thesis focuses on PV absorption enhancement techniques. First, the effect of vertical positioning of plasmonic nanostructures on absorption enhancement was theoretically investigated to understand which one of the three mechanisms usually responsible for the enhancement (forward scattering, diffraction and localized surface plamson) plays the dominant role. Simulation results suggested that the maximum enhancement occurred when placing the nanostructures in the rear side of the cell because of longer path length due to scattering. The experimental effort then switched focus on substrate patterning, which is a less expensive alternative to plasmonic absorption enhancement. Specifically, a nanostructured substrate was prepared by a simple electrochemical process based on two-step aluminum anodization technique. The absorption of thin film silicon deposited on these substrates showed a broadband enhancement. The overall photocurrent density was up to 40% higher than that of films deposited on flat substrates. In conclusion, the studies carried out in this thesis indicate that spectral coupling of LSCs to thin film solar cells could lead to significant improvements in PV output power density. Moreover, while the absorption of thin film solar cells can be enhanced by plasmonic nanostructures, it is shown th

  5. Plasmon Enhanced Hetero-Junction Solar Cell

    NASA Astrophysics Data System (ADS)

    Long, Gen; Ching, Levine; Sadoqi, Mostafa; Xu, Huizhong

    2015-03-01

    Here we report a systematic study of plasmon-enhanced hetero-junction solar cells made of colloidal quantum dots (PbS) and nanowires (ZnO), with/without metal nanoparticles (Au). The structure of solar cell devices was characterized by AFM, SEM and profilometer, etc. The power conversion efficiencies of solar cell devices were characterized by solar simulator (OAI TriSOL, AM1.5G Class AAA). The enhancement in the photocurrent due to introduction of metal nanoparticles was obvious. We believe this is due to the plasmonic effect from the metal nanoparticles. The correlation between surface roughness, film uniformity and device performance was also studied.

  6. Intrinsic cell permeability of the GAGA zinc finger protein into HeLa cells.

    PubMed

    Negi, Shigeru; Terada, Yuka; Suzuyama, Misato; Matsumoto, Haruka; Honbo, Akino; Amagase, Yoko; Mizukawa, Yumiko; Kiriyama, Akiko; Iga, Katsumi; Urushidaini, Tetsuro; Sugiura, Yukio

    2015-09-01

    We examined the intrinsic cell permeability of a GAGA zinc finger obtained from the Drosophila melanogaster transcription factor and analyzed its mechanism of cellular uptake using confocal microscopy and flow cytometry. HeLa cells were treated with the Cy5-labeld GAGA peptides (containing a fluorescent chromophore) to detect fluorescence signals from the fluorescent labeling peptides by confocal microscopy. The results clearly indicated that GAGA peptides possess intrinsic cell permeability for HeLa cells. Based on the results of the flow cytometry analysis and the theoretical net positive charge of the GAGA peptides, the efficiency of cellular uptake of the GAGA peptides was predicted to depend on the net positive charge of the GAGA peptide as well as the cationic component ratio of Arg residues to Lys residues. PMID:26187668

  7. EE580 Solar Cells Todd J. Kaiser

    E-print Network

    Kaiser, Todd J.

    7/21/2010 1 EE580 ­ Solar Cells Todd J. Kaiser · Lecture 03 · Nature of Sunlight 1Montana State University: Solar Cells Lecture 3: Nature of Sunlight Wave-Particle Duality · Light acts as ­ Waves: photons ­ individual packets of energy · Photoelectric Effect · Blackbody Radiation 2Montana State

  8. Elastic Hinge for Solar-Cell Array

    NASA Technical Reports Server (NTRS)

    Mills, R. M.

    1987-01-01

    Elastic hinge folds to small thickness, allows easy replacement of panels attached, and provides part of torque for refolding without additional springs. Holds modules of solar-cell array. Modules kept in open position by external restraint. When restraint removed, elasticity of molybdenum hinge elements helps to fold facing modules together. Hinge developed for foldable modules for solar-cell panels.

  9. (Melanin-Sensitized Solar Cell) : 696220016

    E-print Network

    (Melanin-Sensitized Solar Cell) : : : 696220016 #12; #12;#12; #12;I PLD-sensitized solar cell use. In order to improve such question, this research used the melanin which the human body and the most biology had to regard the dye to catch the photon.The melanin met several requirements

  10. EE580 Solar Cells Todd J. Kaiser

    E-print Network

    Kaiser, Todd J.

    of Electrical Principles · Electric Charge · Electric Current · Electric Fields · Electric Potential Difference University: Solar Cells Lecture 7: EE Fundamentals 5 Electric Current (I) · Movement of charge creates University: Solar Cells Lecture 7: EE Fundamentals What is Electrical Engineering · Opposite of lightning

  11. Zinc sulfide in intestinal cell granules of Ancylostoma caninum adults

    SciTech Connect

    Gianotti, A.J.; Clark, D.T.; Dash, J. )

    1991-04-01

    A source of confusion has existed since the turn of the century about the reddish brown, weakly birefringent 'sphaerocrystals' located in the intestines of strongyle nematodes, Strongylus and Ancylostoma. X-ray diffraction and energy dispersive spectrometric analyses were used for accurate determination of the crystalline order and elemental composition of the granules in the canine hookworm Ancylostoma caninum. The composition of the intestinal pigmented granules was identified unequivocally as zinc sulfide. It seems most probable that the granules serve to detoxify high levels of metallic ions (specifically zinc) present due to the large intake of host blood.

  12. Uptake epithelia behave in a cell-centric and not systems homeostatic manner in response to zinc depletion and supplementation.

    PubMed

    Zheng, Dongling; Feeney, Graham P; Handy, Richard D; Hogstrand, Christer; Kille, Peter

    2014-01-01

    Much remains to be understood about systemic regulation of zinc uptake in vertebrates, and adequate zinc status is far from always achieved in animals or human. In addition to absorbing zinc from the diet, fish are able to take up zinc directly from the water with the gills. This provides an elegant system to study zinc uptake, how it relates to zinc status, and the expression of genes for proteins involved in zinc acquisition. A 21-day experiment was conducted in which zebrafish were acclimated to deficient, control or excess zinc concentrations in the water and feed. Deficient provision of zinc reduced whole body zinc, potassium, sodium and calcium levels whilst zinc concentrations in the uptake epithelia (gills and gut) remained unchanged. Excess levels of zinc caused accumulation of zinc in the gills, intestine and carcass, but impaired whole body iron, sodium and calcium concentrations. Fish subjected to zinc deficiency had, surprisingly, a reduced zinc influx across the gill epithelium, even when tested at a high concentration of zinc in the water. Zinc influx in the excess group was indistinct from the control. Expression of genes for metallothionein-2 (Mt2) and zinc transporters-1, -2, and -8 (Znt1, Znt2, Znt8) in uptake epithelia showed in general a direct relationship with zinc supply, while mRNA for Zip4 was inversely related to zinc supply. Transcripts for the epithelial calcium channel (Ecac/Trpv6) showed time-dependent increased expression in the gills of the deficiency group, and a transient decrease of expression during zinc excess. Transcriptome profiling by microarrays showed that in both gills and intestine, the most markedly affected biological functions were those related to cell growth, proliferation and cancer, closely followed by processes of gene transcription and protein synthesis in general. Whilst changes in zinc supply had profound effects in the intestine on genes associated with uptake and metabolism of macronutrients, many of the unique categories of genes preferentially regulated in the gill could be mapped onto signalling pathways. This included pathways for PPAR/RXR, LXR/RXR, ATM, chemokine, and BMP signalling. Overall, the responses of epithelial tissue to zinc deficiency and excess are best explained by local epithelial homeostasis with no evidence of systemic control. PMID:24301558

  13. SIMULTANEOUS DETERMINATION OF 45CALCIUM AND 65ZINC UPTAKE BY CACO-2 CELLS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We describe a simple method for simultaneously determining cell associated Ca and Zn in Caco-2 cells. Calcium and zinc uptake was measured via radioisotopes 45Ca and 65Zn. Preliminary studies revealed that 65Zn, a positron (+) and gamma emitter, contributed to 45Ca counts in a liquid scintillation...

  14. Epitaxial silicon growth for solar cells

    NASA Technical Reports Server (NTRS)

    Daiello, R. V.; Robinson, P. H.; Richman, D.

    1979-01-01

    The epitaxial procedures, solar cell fabrication, and evaluation techniques are described. The development of baseline epitaxial solar cell structures grown on high quality conventional silicon substrates is discussed. Diagnostic layers and solar cells grown on four potentially low cost silicon substrates are considered. The crystallographic properties of such layers and the performance of epitaxially grown solar cells fabricated on these materials are described. An advanced epitaxial reactor, the rotary disc, is described along with the results of growing solar cell structures of the baseline type on low cost substrates. The add on cost for the epitaxial process is assessed and the economic advantages of the epitaxial process as they relate to silicon substrate selection are examined.

  15. Fullerene surfactants and their use in polymer solar cells

    DOEpatents

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

    2015-12-15

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

  16. High-Temperature Solar Cell Development

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

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

  17. Sensitized energy transfer for organic solar cells, optical solar concentrators, and solar pumped lasers

    E-print Network

    Reusswig, Philip David

    2014-01-01

    The separation of chromophore absorption and excitonic processes, such as singlet exciton fission and photoluminescence, offers several advantages to the design of organic solar cells and luminescent solar concentrators ...

  18. Coating Processes Boost Performance of Solar Cells

    NASA Technical Reports Server (NTRS)

    2012-01-01

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

  19. Development of single cell protectors for sealed silver-zinc cells, phase 1

    NASA Technical Reports Server (NTRS)

    Imamura, M. S.; Donovan, R. L.; Lear, J. W.; Murray, B.

    1976-01-01

    A single cell protector (SCP) assembly capable of protecting a single silver-zinc (Ag Zn) battery cell was designed, fabricated, and tested. The SCP provides cell-level protection against overcharge and overdischarge by a bypass circuit. The bypass circuit consists of a magnetic-latching relay that is controlled by the high and low-voltage limit comparators. Although designed specifically for secondary Ag-Zn cells, the SCP is flexible enough to be adapted to other rechargeable cells. Eighteen SCPs were used in life testing of an 18-cell battery. The cells were sealed Ag-Zn system with inorganic separators. For comparison, another 18-cell battery was subjected to identical life test conditions, but with battery-level protection rather than cell-level. An alternative approach to the SCP design in the form of a microprocessor-based system was conceptually designed. The comparison of SCP and microprocessor approaches is also presented and a preferred approach for Ag-Zn battery protection is discussed.

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

    NASA Technical Reports Server (NTRS)

    Loferski, J. J.

    1976-01-01

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

  1. Semiconductor quantum dot-sensitized solar cells

    PubMed Central

    Tian, Jianjun; Cao, Guozhong

    2013-01-01

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

  2. Hydroponics gel as a new electrolyte gelling agent for alkaline zinc-air cells

    NASA Astrophysics Data System (ADS)

    Othman, R.; Basirun, W. J.; Yahaya, A. H.; Arof, A. K.

    The viability of hydroponics gel as a new alkaline electrolyte gelling agent is investigated. Zinc-air cells are fabricated employing 12 wt.% KOH electrolyte immobilised with hydroponics gel. The cells are discharged at constant currents of 5, 50 and 100 mA. XRD and SEM analysis of the anode plates after discharge show that the failure mode is due to the formation of zinc oxide insulating layers and not due to any side reactions between the gel and the plate or the electrolyte.

  3. Development of gallium arsenide solar cells

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The potential of ion implantation as a means of developing gallium arsenide solar cells with high efficiency performance was investigated. Computer calculations on gallium arsenide cell characteristics are presented to show the effects of surface recombination, junction space-charge recombination, and built-in fields produced by nonuniform doping of the surface region. The fabrication technology is summarized. Electrical and optical measurements on samples of solar cells are included.

  4. Zinc chromate induces chromosome instability and DNA double strand breaks in human lung cells

    SciTech Connect

    Xie Hong; Holmes, Amie L.; Young, Jamie L.; Qin Qin; Joyce, Kellie; Pelsue, Stephen C.; Peng Cheng; Wise, Sandra S.; Jeevarajan, Antony S.; Wallace, William T.; Hammond, Dianne; Wise, John Pierce E-mail: John.Wise@usm.maine.edu

    2009-02-01

    Hexavalent chromium Cr(VI) is a respiratory toxicant and carcinogen, with solubility playing an important role in its carcinogenic potential. Zinc chromate, a water insoluble or 'particulate' Cr(VI) compound, has been shown to be carcinogenic in epidemiology studies and to induce tumors in experimental animals, but its genotoxicity is poorly understood. Our study shows that zinc chromate induced concentration-dependent increases in cytotoxicity, chromosome damage and DNA double strand breaks in human lung cells. In response to zinc chromate-induced breaks, MRE11 expression was increased and ATM and ATR were phosphorylated, indicating that the DNA double strand break repair system was initiated in the cells. In addition, our data show that zinc chromate-induced double strand breaks were only observed in the G2/M phase population, with no significant amount of double strand breaks observed in G1 and S phase cells. These data will aid in understanding the mechanisms of zinc chromate toxicity and carcinogenesis.

  5. Atmospheric pressure chemical vapor deposition of transparent conducting films of fluorine doped zinc oxide and their application

    E-print Network

    crystal flat panel displays, energy efficient windows, gas sensors, surface acoustic wave devices loss or diffusion, which can lead to degra- dation in solar cell efficiency. Zinc oxide is more stable conducting oxides. This suggests zinc oxide may lead to higher solar cell efficiency than tin oxide

  6. Vegetable-based dye-sensitized solar cells.

    PubMed

    Calogero, Giuseppe; Bartolotta, Antonino; Di Marco, Gaetano; Di Carlo, Aldo; Bonaccorso, Francesco

    2015-05-21

    There is currently a large effort to improve the performance of low cost renewable energy devices. Dye-sensitized solar cells (DSSCs) are emerging as one of the most promising low cost photovoltaic technologies, addressing "secure, clean and efficient solar energy conversion". Vegetable dyes, extracted from algae, flowers, fruit and leaves, can be used as sensitizers in DSSCs. Thus far, anthocyanin and betalain extracts together with selected chlorophyll derivatives are the most successful vegetable sensitizers. This review analyses recent progress in the exploitation of vegetable dyes for solar energy conversion and compares them to the properties of synthetic dyes. We provide an in-depth discussion on the main limitation of cell performance e.g. dye degradation, effective electron injection from the dye into the conduction band of semiconducting nanoparticles, such as titanium dioxide and zinc oxide, outlining future developments for the use of vegetable sensitizers in DSSCs. We also discuss the cost of vegetable dyes and how their versatility can boost the advancement of new power management solutions, especially for their integration in living environments, making the practical application of such systems economically viable. Finally, we present our view on future prospects in the development of synthetic analogues of vegetable dyes as sensitizers in DSSCs. PMID:25855097

  7. Final Report: Sintered CZTS Nanoparticle Solar Cells on Metal Foil; July 26, 2011 - July 25, 2012

    SciTech Connect

    Leidholm, C.; Hotz, C.; Breeze, A.; Sunderland, C.; Ki, W.; Zehnder, D.

    2012-09-01

    This is the final report covering 12 months of this subcontract for research on high-efficiency copper zinc tin sulfide (CZTS)-based thin-film solar cells on flexible metal foil. Each of the first three quarters of the subcontract has been detailed in quarterly reports. In this final report highlights of the first three quarters will be provided and details will be given of the final quarter of the subcontract.

  8. ZnS/Zn(O,OH)S-based buffer layer deposition for solar cells

    DOEpatents

    Bhattacharya, Raghu N. (Littleton, CO)

    2009-11-03

    The invention provides CBD ZnS/Zn(O,OH)S and spray deposited ZnS/Zn(O,OH)S buffer layers prepared from a solution of zinc salt, thiourea and ammonium hydroxide dissolved in a non-aqueous/aqueous solvent mixture or in 100% non-aqueous solvent. Non-aqueous solvents useful in the invention include methanol, isopropanol and triethyl-amine. One-step deposition procedures are described for CIS, CIGS and other solar cell devices.

  9. Dye-sensitized Solar Cells for Solar Energy Harvesting

    NASA Astrophysics Data System (ADS)

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

    2011-10-01

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

  10. Bypass diode for a solar cell

    DOEpatents

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

    2013-11-12

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

  11. Solar cell with silicon oxynitride dielectric layer

    DOEpatents

    Shepherd, Michael; Smith, David D

    2015-04-28

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

  12. Heterojunction solar cell with passivated emitter surface

    DOEpatents

    Olson, J.M.; Kurtz, S.R.

    1994-05-31

    A high-efficiency heterojunction solar cell is described wherein a thin emitter layer (preferably Ga[sub 0.52]In[sub 0.48]P) forms a heterojunction with a GaAs absorber layer. A passivating window layer of defined composition is disposed over the emitter layer. The conversion efficiency of the solar cell is at least 25.7%. The solar cell preferably includes a passivating layer between the substrate and the absorber layer. An anti-reflection coating is preferably disposed over the window layer. 1 fig.

  13. Solar Cell Production using UMG Silicon

    SciTech Connect

    Hovel, Harold; Prettyman, Kevin

    2009-09-21

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

  14. Heterojunction solar cell with passivated emitter surface

    DOEpatents

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

    1994-01-01

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

  15. Electrochemistry of the Zinc-Silver Oxide System. Part 2: Practical Measurements of Energy Conversion Using Commercial Miniature Cells.

    ERIC Educational Resources Information Center

    Smith, Michael J.; Vincent, Colin A.

    1989-01-01

    Summarizes the quantitative relationships pertaining to the operation of electrochemical cells. Energy conversion efficiency, cycle efficiency, battery power, and energy/power density of two types of zinc-silver oxide cells are discussed. (YP)

  16. Sinterless Formation Of Contacts On Indium Phosphide

    NASA Technical Reports Server (NTRS)

    Weizer, Victor G.; Fatemi, Navid S.

    1995-01-01

    Improved technique makes it possible to form low-resistivity {nearly equal to 10(Sup-6) ohm cm(Sup2)} electrical contacts on indium phosphide semiconductor devices without damaging devices. Layer of AgP2 40 Angstrom thick deposited on InP before depositing metal contact. AgP2 interlayer sharply reduces contact resistance, without need for sintering.

  17. Transition Metal Phosphide Hydroprocessing Catalysts: A review

    SciTech Connect

    Oyama, S.; Gott, T; Zhao, H; Lee, Y

    2009-01-01

    The diminishing quality of oil feedstocks coupled with increasingly more stringent environmental regulations limiting the content of sulfur in transportation fuels have given rise to a need for improved hydroprocessing technology. This review begins with a summary of the major improvements in hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) catalysts and processes that have been reported in recent years. It then describes a new class of hydroprocessing catalysts, the transition metal phosphides, which have emerged as a promising group of high-activity, stable catalysts. The phosphides have physical properties resembling ceramics, so are strong and hard, yet retain electronic and magnetic properties similar to metals. Their crystal structures are based on trigonal prisms, yet they do not form layered structures like the sulfides. They display excellent performance in HDS and HDN, with the most active phosphide, Ni{sub 2}P, having activity surpassing that of promoted sulfides on the basis of sites titrated by chemisorption (CO for the phosphides, O{sub 2} for the sulfides). In the HDS of difficult heteroaromatics like 4,6-dimethyldibenzothiophene Ni{sub 2}P operates by the hydrogenation pathway, while in the HDN of substituted nitrogen compounds like 2-methylpiperidine it carries out nucleophilic substitution. The active sites for hydrogenation in Ni{sub 2}P have a square pyramidal geometry, while those for direct hydrodesulfurization have a tetrahedral geometry. Overall, Ni{sub 2}P is a promising catalyst for deep HDS in the presence of nitrogen and aromatic compounds.

  18. Polymer-fullerene composite solar cells.

    PubMed

    Thompson, Barry C; Fréchet, Jean M J

    2008-01-01

    Fossil fuel alternatives, such as solar energy, are moving to the forefront in a variety of research fields. Polymer-based organic photovoltaic systems hold the promise for a cost-effective, lightweight solar energy conversion platform, which could benefit from simple solution processing of the active layer. The function of such excitonic solar cells is based on photoinduced electron transfer from a donor to an acceptor. Fullerenes have become the ubiquitous acceptors because of their high electron affinity and ability to transport charge effectively. The most effective solar cells have been made from bicontinuous polymer-fullerene composites, or so-called bulk heterojunctions. The best solar cells currently achieve an efficiency of about 5%, thus significant advances in the fundamental understanding of the complex interplay between the active layer morphology and electronic properties are required if this technology is to find viable application. PMID:18041798

  19. Radiative cooling of solar cells LINXIAO ZHU,1

    E-print Network

    Fan, Shanhui

    increased temperature of the solar cell has adverse consequences on both its efficiency and its reliability for power conversion effi- ciency of around 33.7% [1] under the AM1.5 solar spectrum. Thus, while a solar for the performance and reli- ability of solar cells. The conversion efficiency of solar cells typically deteriorates

  20. Improved CMX solar cell coverglasses and optical solar reflectors

    NASA Astrophysics Data System (ADS)

    Whalley, A. M.; Jones, D. P.; Dollery, A. A.; Murphy, N.; Porter, D. A.

    Recent development programs have demonstrated that considerable improvements in optical and thermooptical performance as well as mechanical properties of CMX solar cell coverglasses and optical solar reflectors (OSRs) can be achieved. Optical coatings can increase infrared emittance by 4 percent and decrease solar absorptance by 50 percent. Chemical treatments can be used to increase glass strength to four times its untreated value or to provide integral antireflection layers which reduce reflection to 0.5 percent per surface. Automated test equipment for proving the strength of each coverglass and mirror has been designed and manufactured.

  1. Transparent superstrate terrestrial solar cell module

    NASA Technical Reports Server (NTRS)

    1977-01-01

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

  2. Diffused junction p(+)-n solar cells in bulk GaAs. I Fabrication and cell performance

    NASA Technical Reports Server (NTRS)

    Bhat, I.; Bhat, K. N.; Mathur, G.; Borrego, J. M.; Ghandhi, S. K.

    1984-01-01

    This paper describes the fabrication of solar cells made by a simple open tube p(+)-diffusion into bulk n-GaAs. In addition, cell performance is provided as an indicator of the quality of bulk GaAs for this application. Initial results using this technique (12.2 percent efficiency at AM1 for 0.5 sq cm cells) are promising, and indicate directions for materials improvement. It is shown that the introduction of the diffusant (zinc) with point defects significantly affects the material properties and results in an increase in current capability.

  3. Dye-sensitized solar cells

    DOEpatents

    Skotheim, T.A.

    1980-03-04

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

  4. Dye-sensitized solar cells

    DOEpatents

    Skotheim, Terje A. [Berkeley, CA

    1980-03-04

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

  5. Rapid, efficient charging of lead-acid and nickel-zinc traction cells. [for electric vehicles

    NASA Technical Reports Server (NTRS)

    Smithrick, J. J.

    1978-01-01

    Lead-acid and nickel-zinc traction cells were rapidly and efficiently charged using a high rate taped dc charge (HRTDC) method which could possibly be used for on-the-road service recharge of electric vehicles. The HRTDC method takes advantage of initial high cell charge acceptance and uses cell gassing rate and temperature as an indicator of charging efficiency. On the average, 300 amp-hour nickel-zinc traction cells were given a HRTDC to 78% of rated amp-hour capacity within 53 minutes at an amp-hour efficiency of 92% and an energy efficiency of 52%. Three-hundred amp-hour lead-acid traction cells were charged to 69% of rated amp-hour capacity within 46 minutes at an amp-hour efficiency of 91% with an energy efficiency of 64%.

  6. Annular Electrode Improves Solar-Cell Welds

    NASA Technical Reports Server (NTRS)

    Baraona, C. R.; Forestieri, A. F.; Frey, W. E.

    1982-01-01

    Improved method of electrical-resistance welding of solar-cell inter-connections developed by using an annular welding-electrode shape. Improved weld electrode consists of two coaxial cylinders, outer one with annular cross section and inner one with circular cross section. Possible annular weld-electrode configurations result in better quality welds for interconnecting solar-array elements.

  7. Quantum Junction Solar Cells Jiang Tang,,

    E-print Network

    Sargent, Edward H. "Ted"

    power conversion efficiencies of 5.4%. Control over doping in quantum solids, and the successful having record 43.5% efficiency under solar concentration.3 This demands optimization of multiple, the benefit of quantum tuning has, at best, been half-realized. Constructing a solar cell in which

  8. P/N InP solar cells on Ge wafers

    NASA Technical Reports Server (NTRS)

    Wojtczuk, Steven; Vernon, Stanley; Burke, Edward A.

    1994-01-01

    Indium phosphide (InP) P-on-N one-sun solar cells were epitaxially grown using a metalorganic chemical vapor deposition process on germanium (Ge) wafers. The motivation for this work is to replace expensive InP wafers, which are fragile and must be thick and therefore heavy, with less expensive Ge wafers, which are stronger, allowing use of thinner, lighter weight wafers. An intermediate InxGs1-xP grading layer starting as In(0.49)Ga(0.51) at the GaAs-coated Ge wafer surface and ending as InP at the top of the grading layer (backside of the InP cell) was used to attempt to bend some of the threading dislocations generated by lattice-mismatch between the Ge wafer and InP cell so they would be harmlessly confined in this grading layer. The best InP/Ge cell was independently measured by NASA-Lewis with a one-sun 25 C AMO efficiently measured by NASA-Lewis with a one-circuit photocurrent 22.6 mA/sq cm. We believe this is the first published report of an InP cell grown on a Ge wafer. Why get excited over a 9 percent InP/Ge cell? If we look at the cell weight and efficiency, a 9 percent InP cell on an 8 mil Ge wafer has about the same cell power density, 118 W/kg (BOL), as the best InP cell ever made, a 19 percent InP cell on an 18 mil InP wafer, because of the lighter Ge wafer weight. As cell panel materials become lighter, the cell weight becomes more important, and the advantage of lightweight cells to the panel power density becomes more important. In addition, although InP/Ge cells have a low beginning-of-life (BOL) efficiency due to dislocation defects, the InP/Ge cells are very radiation hard (end-of-life power similar to beginning-of-life). We have irradiated an InP/Ge cell with alpha particles to an equivalent fluence of 1.6 x 10(exp 16) 1 MeV electrons/sq cm and the efficiency is still 83 percent of its BOL value. At this fluence level, the power output of these InP/Ge cells matches the GaAs/Ge cell data tabulated in the JPL handbook. Data are presented indicating InP/Ge has more power output than GaAs/Ge cells at fluences in excess of this value.

  9. Study of the effects of impurities on the properties of silicon materials and performance of silicon solar cell

    NASA Technical Reports Server (NTRS)

    Sah, C. T.

    1980-01-01

    Zinc is a major residue impurity in the preparation of solar grade silicon material by the zinc vapor reduction of silicon tetrachloride. It was found that in order to get a 17 percent AMl cell efficiency, the concentration of the zinc recombination centers in the base region of silicon solar cells must be less than 4 x 10 to the 11th power Zn/cu cm in the p-base n+/p/p+ cell and 7 x 10 to the 11th power Zn/cu cm in the n-base p+/n/n+ cell for a base dopant impurity concentration of 5 x 10 to the 14th power atoms/cu cm. If the base dopant impurity concentration is increased by a factor of 10 to 5 x 10 to the 15th power atoms/cu cm, then the maximum allowable zinc concentration is increased by a factor of about two for a 17 percent AMl efficiency. The thermal equilibrium electron and hole recombination and generation rates at the double acceptor zinc cancers were obtained from previous high field measurements as well as new measurements at zero field. The rates were used in the exact d.c. circuit model to compute the projections.

  10. Perovskite solar cells: Continuing to soar

    NASA Astrophysics Data System (ADS)

    McGehee, Michael D.

    2014-09-01

    The dream of printing highly efficient solar cells is closer than ever to being realized. Solvent engineering has enabled the deposition of uniform perovskite semiconductor films that yield greater than 15% power-conversion efficiency.

  11. Advanced Silicon Space Solar Cells Using Nanotechnology

    SciTech Connect

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

    1999-03-31

    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.

  12. Colloidal cluster phases and solar cells 

    E-print Network

    Mailer, Alastair George

    2012-11-28

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

  13. Solar cell array design handbook, volume 1

    NASA Technical Reports Server (NTRS)

    Rauschenbach, H. S.

    1976-01-01

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

  14. Solar Cells: Slicing and Dicing Photons

    SciTech Connect

    Ellingson, R.

    2008-02-01

    Solar cells take advantage of our most abundant source of energy, the Sun. A technique that improves the conversion of photons to electrons could potentially lead to a dramatic improvement in device efficiency.

  15. Colloidal Nanoparticles for Intermediate Band Solar Cells.

    PubMed

    Vörös, Márton; Galli, Giulia; Zimanyi, Gergely T

    2015-07-28

    The Intermediate Band (IB) solar cell concept is a promising idea to transcend the Shockley-Queisser limit. Using the results of first-principles calculations, we propose that colloidal nanoparticles (CNPs) are a viable and efficient platform for the implementation of the IB solar cell concept. We focused on CdSe CNPs and we showed that intragap states present in the isolated CNPs with reconstructed surfaces combine to form an IB in arrays of CNPs, which is well separated from the valence and conduction band edges. We demonstrated that optical transitions to and from the IB are active. We also showed that the IB can be electron doped in a solution, e.g., by decamethylcobaltocene, thus activating an IB-induced absorption process. Our results, together with the recent report of a nearly 10% efficient CNP solar cell, indicate that colloidal nanoparticle intermediate band solar cells are a promising platform to overcome the Shockley-Queisser limit. PMID:26042468

  16. Rational design of hybrid organic solar cells

    E-print Network

    Lentz, Levi (Levi Carl)

    2014-01-01

    In this thesis, we will present a novel design for a nano-structured organic-inorganic hybrid photovoltaic material that will address current challenges in bulk heterojunction (BHJ) organic-based solar cell materials. ...

  17. Texturization of multicrystalline silicon solar cells

    E-print Network

    Li, Dai-Yin

    2010-01-01

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

  18. Indium oxide/n-silicon heterojunction solar cells

    DOEpatents

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

    1982-12-28

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

  19. Recent advances in flexible perovskite solar cells.

    PubMed

    Susrutha, B; Giribabu, Lingamallu; Singh, Surya Prakash

    2015-09-22

    Flexible and low-weight thin-film perovskite solar cells have attracted considerable attention for developing large-area, roll-to-roll and differently shaped photovoltaics with improved power conversion efficiencies. In this review, we describe how researchers have adopted different approaches to enhance the device performance of the flexible perovskite solar cells to compete with rigid substrates with tailored electron/hole transport materials and flexible substrates. PMID:26198773

  20. Silicon solar cells, a manufacturing cost analysis

    NASA Technical Reports Server (NTRS)

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

    1978-01-01

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

  1. Stretchable, wearable dye-sensitized solar cells.

    PubMed

    Yang, Zhibin; Deng, Jue; Sun, Xuemei; Li, Houpu; Peng, Huisheng

    2014-05-01

    A stretchable, wearable dye-sensitized solar-cell textile is developed from elastic, electrically conducting fiber as a counter electrode and spring-like titanium wire as the working electrode. Dyesensitized solar cells are demonstrated with energy-conversion efficiencies up to 7.13%. The high energy-conversion efficiencies can be well maintained under stretch by 30% and after stretch for 20 cycles. PMID:24648169

  2. High-temperature Solar Cell Development

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

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

  3. statistical physics statistics of radiation Efficiency of a Solar Cell

    E-print Network

    statistical physics statistics of radiation Efficiency of a Solar Cell In this problem, we will show that simple physics constrains the efficiency of a solar cell. Consider a planar solar cell) Suppose that the solar cell can only absorb radiation quanta from the sun with an energy greater than

  4. Cost-effective nanostructured thin-film solar cell with enhanced absorption

    NASA Astrophysics Data System (ADS)

    Wang, Peng Hui; Nowak, Regina-Elisabeth; Geißendörfer, Stefan; Vehse, Martin; Reininghaus, Nies; Sergeev, Oleg; von Maydell, Karsten; Brolo, Alexandre G.; Agert, Carsten

    2014-11-01

    Nanostructured transparent conductive electrodes are highly interesting for efficient light management in thin-film solar cells, but they are often costly to manufacture and limited to small scales. This work reports on a low-cost and scalable bottom-up approach to fabricate nanostructured thin-film solar cells. A folded solar cell with increased optical absorber volume was deposited on honeycomb patterned zinc oxide nanostructures, fabricated in a combined process of nanosphere lithography and electrochemical deposition. The periodicity of the honeycomb pattern can be easily varied in the fabrication process, which allows structural optimization for different absorber materials. The implementation of this concept in amorphous silicon thin-film solar cells with only 100 nm absorber layer was demonstrated. The nanostructured solar cell showed approximately 10% increase in the short circuit current density compared to a cell on an optimized commercial textured reference electrode. The concept presented here is highly promising for low-cost industrial fabrication of nanostructured thin-film solar cells, since no sophisticated layer stacks or expensive techniques are required.

  5. Achieving High Performance Perovskite Solar Cells

    NASA Astrophysics Data System (ADS)

    Yang, Yang

    2015-03-01

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

  6. Perovskite solar cells: from materials to devices.

    PubMed

    Jung, Hyun Suk; Park, Nam-Gyu

    2015-01-01

    Perovskite solar cells based on organometal halide light absorbers have been considered a promising photovoltaic technology due to their superb power conversion efficiency (PCE) along with very low material costs. Since the first report on a long-term durable solid-state perovskite solar cell with a PCE of 9.7% in 2012, a PCE as high as 19.3% was demonstrated in 2014, and a certified PCE of 17.9% was shown in 2014. Such a high photovoltaic performance is attributed to optically high absorption characteristics and balanced charge transport properties with long diffusion lengths. Nevertheless, there are lots of puzzles to unravel the basis for such high photovoltaic performances. The working principle of perovskite solar cells has not been well established by far, which is the most important thing for understanding perovksite solar cells. In this review, basic fundamentals of perovskite materials including opto-electronic and dielectric properties are described to give a better understanding and insight into high-performing perovskite solar cells. In addition, various fabrication techniques and device structures are described toward the further improvement of perovskite solar cells. PMID:25358818

  7. Molecular solution processing of metal chalcogenide thin film solar cells

    NASA Astrophysics Data System (ADS)

    Yang, Wenbing

    The barrier to utilize solar generated electricity mainly comes from their higher cost relative to fossil fuels. However, innovations with new materials and processing techniques can potentially make cost effective photovoltaics. One such strategy is to develop solution processed photovoltaics which avoid the expensive vacuum processing required by traditional solar cells. The dissertation is mainly focused on two absorber material system for thin film solar cells: chalcopyrite CuIn(S,Se)2 (CISS) and kesterite Cu2ZnSn(S,Se) 4 organized in chronological order. Chalcopyrite CISS is a very promising material. It has been demonstrated to achieve the highest efficiency among thin film solar cells. Scaled-up industry production at present has reached the giga-watt per year level. The process however mainly relies on vacuum systems which account for a significant percentage of the manufacturing cost. In the first section of this dissertation, hydrazine based solution processed CISS has been explored. The focus of the research involves the procedures to fabricate devices from solution. The topics covered in Chapter 2 include: precursor solution synthesis with a focus on understanding the solution chemistry, CISS absorber formation from precursor, properties modification toward favorable device performance, and device structure innovation toward tandem device. For photovoltaics to have a significant impact toward meeting energy demands, the annual production capability needs to be on TW-level. On such a level, raw materials supply of rare elements (indium for CIS or tellurium for CdTe) will be the bottleneck limiting the scalability. Replacing indium with zinc and tin, earth abundant kesterite CZTS exhibits great potential to reach the goal of TW-level with no limitations on raw material availability. Chapter 3 shows pioneering work towards solution processing of CZTS film at low temperature. The solution processed devices show performances which rival vacuum-based techniques and is partially attributed to the ease in controlling composition and CZTS phase through this technique. Based on this platform, comprehensive characterization on CZTS devices is carried out including solar cells and transistors. Especially defects properties are exploited in Chapter 4 targeting to identify the limiting factors for further improvement on CZTS solar cells efficiency. Finally, molecular structures and precursor solution stability have been explored, potentially to provide a universal approach to process multinary compounds.

  8. Rapid, efficient charging of lead-acid and nickel-zinc traction cells

    NASA Technical Reports Server (NTRS)

    Smithrick, J. J.

    1978-01-01

    Lead-acid and nickel-zinc traction cells were rapidly and efficiently charged using a high rate tapered direct current (HRTDC) charge method which could possibly be used for on-the-road service recharge of electric vehicles. The HRTDC method takes advantage of initial high cell charge acceptance and uses cell gassing rate and temperature as an indicator of charging efficiency. On the average, in these preliminary tests, 300 amp-hour nickel-zinc traction cells were given a HRTDC (initial current 500 amps, final current 100 amps) to 78 percent of rated amp-hour capacity within 53 minutes at an amp-hour efficiency of 92 percent and an energy efficiency of 52 percent. Three hundred amp-hour lead-acid traction cells were charged to 69 percent of rated amp-hour capacity within 46 minutes at an amp-hour efficiency of 91 percent with an energy efficiency of 64 percent. In order to find ways to further decrease the recharge times, the effect of periodically (0 to 400 Hz) pulse discharging cells during a constant current charging process (94% duty cycle) was investigated. Preliminary data indicate no significant effect of this type of pulse discharging during charge on charge acceptance of lead-acid or nickel-zinc cells.

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

    SciTech Connect

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

    2011-12-15

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

  10. Solar cells fabricated with unconventional silicon materials

    NASA Technical Reports Server (NTRS)

    Minahan, J. A.; Castorena, E.; Dionne, D. J.

    1981-01-01

    Solar cells have been fabricated using silicon materials supplied in the DOE/JPL Large Solar Array program. Each of the silicon materials studied in this program was produced in a unique manner and with intent of producing silicon in a grade and form that would offer the possibility of economic deployment in photovoltaic arrays for generation of electricity. This report will attempt to provide an overview of the results for some of the materials and highlight in particular results obtained for solar cells fabricated from the advanced CZ silicon. Emphasis will be given to consideration of the purity of virgin silicon material used in the heat exchange method.

  11. Plastic Schottky-barrier solar cells

    DOEpatents

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

    1981-12-30

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

  12. Large area space solar cell assemblies

    NASA Technical Reports Server (NTRS)

    Nowlan, M. J.; Spitzer, M. B.

    1982-01-01

    Results of the development of a 34.3 sq cm space solar cell and integral glass cover are presented. Average AM(0) cell efficiency is 14 percent. The cell design includes a high performance back surface reflector yielding a thermal alpha of approximately 0.66. A novel process is described which integrates cell fabrication and encapsulation thereby achieving a reduction of encapsulation cost. Test results indicate the potential of this new technology.

  13. MIS silicon solar cells: potential advantages

    SciTech Connect

    Cheek, G.; Mertens, R.

    1981-05-01

    Recent progress with silicon solar cells based on the MIS or SIS structure is reviewed. To be competitive with pn junction technology in the near term, these cells must be much cheaper or have a higher efficiency in a production environment. Apparently, the minority carrier MIS cells have the greatest potential for large-scale applications. The data currently indicate that all types of MIS/SIS cells have some inherent instability problems.

  14. Zinc inhibits ethanol-induced HepG2 cell apoptosis

    SciTech Connect

    Szuster-Ciesielska, Agnieszka Plewka, Krzysztof; Daniluk, Jadwiga; Kandefer-Szerszen, Martyna

    2008-05-15

    Alcohol consumption produces a variety of metabolic alterations in liver cells, associated with ethanol oxidation and with nonoxidative metabolism of ethanol, among others apoptosis of hepatocytes. As zinc is known as a potent antioxidant and an inhibitor of cell apoptosis, the aim of this paper was to investigate whether zinc supplementation could inhibit ethanol-induced HepG2 apoptosis, and whether this inhibition was connected with attenuation of oxidative stress and modulation of FasR/FasL system expression. The results indicated that zinc supplementation significantly inhibited ethanol-induced HepG2 cell apoptosis (measured by cytochrome c release from mitochondria and caspase-3 activation) by attenuation of reactive oxygen species (ROS) production, increase in the cellular level of GSH, inhibition of ethanol-induced sFasR and FasL overexpression and caspase-8 activation. These results indicate that zinc can inhibit ethanol-induced hepatocyte apoptosis by several independent mechanisms, among others by an indirect antioxidative effect and probably by inhibition of caspase-8 and caspase-9 activation.

  15. Advanced Solar Cells for Satellite Power Systems

    NASA Technical Reports Server (NTRS)

    Flood, Dennis J.; Weinberg, Irving

    1994-01-01

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

  16. Green synthesis of wurtzite copper zinc tin sulfide nanocones for improved solar photovoltaic utilization

    NASA Astrophysics Data System (ADS)

    Arora, Leena; Gupta, Poonam; Chhikara, Nitu; Singh, Om Pal; Muhunthan, N.; Singh, V. N.; Singh, B. P.; Jain, Kiran; Chand, S.

    2015-02-01

    Cu2ZnSnS4 (CZTS) is considered to be one of the most promising light absorbing materials for low-cost and high-efficiency thin-film solar cells. It is composed of earth abundant, non-toxic elements. In the present study, wurtzite CZTS nanocone has been synthesized by a green chemistry route. The nanocones have been characterized for its optical, structural and microstructural properties using UV-Vis spectrophotometer, X-ray diffraction, Raman spectroscopy and high-resolution transmission electron microscopy. Optical absorption result shows a band gap of 1.42 eV. XRD and Raman results show wurtzite structure and TEM studies reveal the nanocone structure of the grown material. Growing vertically aligned nanocone structure having smaller diameter shall help in enhancing the light absorption in broader range which shall enhance the efficiency of solar cell. This study is a step in this direction.

  17. Optimization and performance of Space Station Freedom solar cells

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

  18. Manufacture of Solar Cells on the Moon

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    2007-01-01

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

  20. Antireflection coatings designed by the average uniform algorithm for thin film solar cells.

    PubMed

    Rajbhandari, Pravakar P; Emrani, Amin; Dhakal, Tara P; Westgate, Charles R; Klotzkin, David

    2014-12-01

    Effective coatings improve the performance of any device designed to emit or collect light over a range of angles and wavelengths. Improved broadband and wide angle antireflection coatings (ARCs) are a simple and direct way to improve solar cell performance. In this paper we demonstrate a multilayered ARC optimized using a new meta-heuristic algorithm called the average uniform algorithm (AUA). Comparison between the well-known genetic algorithm and the AUA showed that both achieved similar results but the AUA converged much faster. The coating optimized by AUA for broadband and wide-angle emission is applied to a copper zinc tin sulfide based thin film solar cell by co-sputtering of high and low refractive index material. A significant improvement in efficiency was observed over wide angle and bandwidth with a typical improvement of 15% over the uncoated solar cell. This AUA methodology is proven to be an efficient method for design of general ARCs. PMID:25607956

  1. Nanoparticle Solar Cell Final Technical Report

    SciTech Connect

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

    2008-06-17

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

  2. The consequences of kesterite equilibria for efficient solar cells.

    PubMed

    Redinger, Alex; Berg, Dominik M; Dale, Phillip J; Siebentritt, Susanne

    2011-03-16

    Copper-zinc-tin-chalcogenide kesterites, Cu(2)ZnSnS(4) and Cu(2)ZnSnSe(4) (CZTS(e)) are ideal candidates for the production of thin film solar cells on large scales due to the high natural abundance of all constituents, a tunable direct band gap ranging from 1.0 to 1.5 eV, a large absorption coefficient, and demonstrated power conversion efficiencies close to 10%. However, Sn losses through desorption of SnS(e) from CZTS(e) at elevated temperatures (above 400 °C) impede the thorough control of film composition and film homogeneity. No robust and feasible fabrication process is currently available. Here we show that understanding the formation reaction of the kesterite absorber is the key to control the growth process and to drastically improve the solar cell efficiency. Furthermore, we demonstrate that this knowledge can be used to simplify the four-dimensional parameter space (spanned by the four different elements) to an easy and robust two-dimensional process. Sufficiently high partial pressures of SnS(e) and S(e) (a) prevent the decomposition reaction of the CZTS(e) at elevated temperatures and (b) introduce any missing Sn into a Sn-deficient film. This finding enables us to simplify the precursor to a film containing only Cu and Zn, whereas Sn and S(e) are introduced from the gas phase by a self-regulating process. PMID:21329385

  3. Chemically Deposited Thin-Film Solar Cell Materials

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

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

  4. INKJET PRINTING OF NICKEL AND SILVER METAL SOLAR CELL CONTACTS

    SciTech Connect

    Pasquarelli, R.; Curtis, C.; Van Hest, M.

    2008-01-01

    With about 125,000 terawatts of solar power striking the earth at any given moment, solar energy may be the only renewable energy resource with enough capacity to meet a major portion of our future energy needs. Thin-fi lm technologies and solution deposition processes seek to reduce manufacturing costs in order to compete with conventional coal-based electricity. Inkjet printing, as a derivative of the direct-write process, offers the potential for low-cost, material-effi cient deposition of the metals for photovoltaic contacts. Advances in contact metallizations are important because they can be employed on existing silicon technology and in future-generation devices. We report on the atmospheric, non-contact deposition of nickel (Ni) and silver (Ag) metal patterns on glass, Si, and ZnO substrates at 180–220°C from metal-organic precursor inks using a Dimatix inkjet printer. Near-bulk conductivity Ag contacts were successfully printed up to 4.5 ?m thick and 130 ?m wide on the silicon nitride antirefl ective coating of silicon solar cells. Thin, high-resolution Ni adhesion-layer lines were printed on glass and zinc oxide at 80 ?m wide and 55 nm thick with a conductivity two orders of magnitude less than the bulk metal. Additionally, the ability to print multi-layered metallizations (Ag on Ni) on transparent conducting oxides was demonstrated and is promising for contacts in copper-indium-diselenide (CIS) solar cells. Future work will focus on further improving resolution, printing full contact devices, and investigating copper inks as a low-cost replacement for Ag contacts.

  5. Method of fabricating a solar cell array

    DOEpatents

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

    1982-01-01

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

  6. Liquid cooled, linear focus solar cell receiver

    DOEpatents

    Kirpich, Aaron S. (Broomall, PA)

    1985-01-01

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

  7. Liquid cooled, linear focus solar cell receiver

    DOEpatents

    Kirpich, A.S.

    1983-12-08

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

  8. - and Perovskite-Sensitised Mesoscopic Solar Cells

    NASA Astrophysics Data System (ADS)

    Grätzel, Michael; Durrant, James R.

    2015-10-01

    The following sections are included: * Introduction * Historical background * Mode of function of dye-sensitised solar cells * DSSC research and development * Solid-state mesoscopic cells based on molecular dyes or perovskite pigments as sensitisers * Pilot production of modules, field tests and commercial DSSC development * Outlook * Acknowledgements * References

  9. Walking-Beam Solar-Cell Conveyor

    NASA Technical Reports Server (NTRS)

    Feder, H.; Frasch, W.

    1982-01-01

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

  10. Method of restoring degraded solar cells

    DOEpatents

    Staebler, David L. (Lawrenceville, NJ)

    1983-01-01

    Amorphous silicon solar cells have been shown to have efficiencies which degrade as a result of long exposure to light. Annealing such cells in air at a temperature of about 200.degree. C. for at least 30 minutes restores their efficiency.

  11. Method of restoring degraded solar cells

    DOEpatents

    Staebler, D.L.

    1983-02-01

    Amorphous silicon solar cells have been shown to have efficiencies which degrade as a result of long exposure to light. Annealing such cells in air at a temperature of about 200 C for at least 30 minutes restores their efficiency. 2 figs.

  12. Hotspot Endurance Of Solar-Cell Modules

    NASA Technical Reports Server (NTRS)

    Gonzalez, C. C.; Sugimura, R. S.; Ross, R. G., Jr.

    1989-01-01

    Procedure for evaluating modules for use with concentrators now available. Solar simulator illuminates photovoltaic cells through Fresnel lens of concentrator module. Module and test cells inspected visually at 24-h intervals during test and again when test completed. After test, electrical characteristics of module measured for comparison with pretest characteristics.

  13. Inexpensive Antireflection Coating for Solar Cells

    NASA Technical Reports Server (NTRS)

    Tracy, C. E.; Kern, W.; Vibronek, R. D.

    1982-01-01

    Continuous method for applying antireflection coating to solar cells increases efficiency of devices by preventing energy from being reflected away, but adds little to manufacturing cost. Method consists of spraying solution on cells or glass collector plates, drying sprayed layer, and curing it. Solution is formulated to spread evenly over surfaces.

  14. High-efficiency concentrator silicon solar cells

    SciTech Connect

    Sinton, R.A.; Cuevas, A.; King, R.R.; Swanson, R.M. . Solid-State Electronics Lab.)

    1990-11-01

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

  15. Microstructural analysis of solar cell welds

    NASA Technical Reports Server (NTRS)

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

    1982-01-01

    Parallel-gap resistance welding of silicon solar cells with copper interconnects results in complex microstructural variations that depend on the welding variables. At relatively low heat input solid-state welds are produced. At medium heat the Ag-Cu eutectic forms resulting in a braze joint. High heat produces a fusion weld with complete melting of the silver layer on the silicon solar cell. If the silicon is also melted, cracking occurs in the silicon cell below the weld nugget. These determinations were made using light microscopy, microprobe, and scanning electron microscopy analyses.

  16. Gestational marginal zinc deficiency impaired fetal neural progenitor cell proliferation by disrupting the ERK1/2 signaling pathway.

    PubMed

    Nuttall, Johnathan R; Supasai, Suangsuda; Kha, Jennifer; Vaeth, Brandon M; Mackenzie, Gerardo G; Adamo, Ana M; Oteiza, Patricia I

    2015-11-01

    This study investigated if a marginal zinc deficiency during gestation in rats could affect fetal neural progenitor cell (NPC) proliferation through a down-regulation of the extracellular signal-regulated kinase (ERK1/2) signaling pathway. Rats were fed a marginally zinc-deficient or adequate diet from the beginning of gestation until embryonic day (E)19. The proportion of proliferating cells in the E19 fetal ventricular zone was decreased by marginal zinc deficiency. Immunostaining for phosphorylated ERK1/2 in the cerebral cortex was decreased in the marginal zinc fetuses, and this effect was strongest in the ventricular zone. Furthermore, phosphorylation of the upstream mitogen-activated ERK kinases (MEK1/2) was not affected, suggesting that marginal zinc deficiency could have increased ERK-directed phosphatase activity. Similar findings were observed in cultured rat embryonic cortical neurons and in IMR-32 neuroblastoma cells, in which zinc-deficiency decreased ERK1/2 phosphorylation without affecting MEK1/2 phosphorylation. Indeed, zinc deficiency increased the activity of the ERK-directed phosphatase protein phosphatase 2A (PP2A) in the fetal cortex and IMR-32 cells. Inhibition of PP2A with okadaic acid prevented the decrease in ERK phosphorylation and proliferation of zinc-deficient IMR-32 cells. Together these results demonstrated that decreased zinc availability reduces ERK1/2 signaling and decreased NPC proliferation as a consequence of PP2A activation. Disruption of fetal neurogenesis could underlie irreversible neurobehavioral impairments observed after even marginal zinc nutrition during a critical period of early brain development. PMID:26153680

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

    SciTech Connect

    Yang, Weiquan; Becker, Jacob; Liu, Shi; Kuo, Ying-Shen; Li, Jing-Jing; Zhang, Yong-Hang; Landini, Barbara; Campman, Ken

    2014-05-28

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

  18. Collection efficiency measurements for solar cell research

    NASA Technical Reports Server (NTRS)

    Hampton, H. L.; Olsen, L. C.

    1976-01-01

    A system was established for measuring absolute, spectral collection efficiency that is well suited to solar cell research and development. Determination of spectral collection efficiency involves measurements of the incident photon intensity, the device reflection coefficient, and the cell short circuit current. A monochromatic photon flux is obtained with a high intensity Bausch and Lomb monochromator, and an Epply thermopile detector is used to measure incident intensity. Normal incidence reflectivity measurements are achieved with a prism type beam splitter. The experimental approach is discussed, measurements of the reflectivity of evaporated silver films are considered. Collection efficiency measurements of silicon solar cells are presented, and collection efficiency studies of Cu20 solar cells are discussed.

  19. Solar Cell Calibration and Measurement Techniques

    NASA Technical Reports Server (NTRS)

    Bailey, Sheila; Brinker, Dave; Curtis, Henry; Jenkins, Phillip; Scheiman, Dave

    1997-01-01

    The increasing complexity of space solar cells and the increasing international markets for both cells and arrays has resulted in workshops jointly sponsored by NASDA, ESA and NASA. These workshops are designed to obtain international agreement on standardized values for the AMO spectrum and constant, recommend laboratory measurement practices and establish a set of protocols for international comparison of laboratory measurements. A working draft of an ISO standard, WDI 5387, 'Requirements for Measurement and Calibration Procedures for Space Solar Cells' was discussed with a focus on the scope of the document, a definition of primary standard cell, and required error analysis for all measurement techniques. Working groups addressed the issues of Air Mass Zero (AMO) solar constant and spectrum, laboratory measurement techniques, and the international round robin methodology. A summary is presented of the current state of each area and the formulation of the ISO document.

  20. High efficiency low cost solar cell power

    NASA Technical Reports Server (NTRS)

    Bekey, I.; Blocker, W.

    1978-01-01

    A concept for generating high-efficiency, low-cost, solar-cell power is outlined with reference to solar cell parameters, optical concentrators, and thermal control procedures. A design for a 12.5-kw power module for space operation is discussed noting the optical system, spectrum splitter, light conversion system, cell cooling, power conditioner, and tracking mechanism. It is found that for an unconcentrated array, efficiency approaches 60% when ten or more bandgaps are used. For a 12-band system, a computer program distributed bandgaps for maximum efficiency and equal cell currents. Rigid materials and thin films have been proposed for optical components and prisms, gratings, and dichroic mirrors have been recommended for spectrum splitting. Various radiator concepts are noted including that of Weatherston and Smith (1960) and Hedgepeth and Knapp (1978). The concept may be suitable for the Solar Power Satellite.

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

    PubMed

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

    2016-02-01

    Despite the increasing use of photovoltaics their potential environmental risks are poorly understood. Here, we compared ecotoxicological effects of two thin-film photovoltaics: established copper indium gallium selenide (CIGS) and organic photovoltaic (OPV) cells. Leachates were produced by exposing photovoltaics to UV light, physical damage, and exposure to environmentally relevant model waters, representing mesotrophic lake water, acidic rain, and seawater. CIGS cell leachates contained 583?gL(-1) molybdenum at lake water, whereas at acidic rain and seawater conditions, iron, copper, zinc, molybdenum, cadmium, silver, and tin were present up to 7219?gL(-1). From OPV, copper (14?gL(-1)), zinc (87?gL(-1)) and silver (78?gL(-1)) leached. Zebrafish embryos were exposed until 120h post-fertilization to these extracts. CIGS leachates produced under acidic rain, as well as CIGS and OPV leachates produced under seawater conditions resulted in a marked hatching delay and increase in heart edema. Depending on model water and solar cell, transcriptional alterations occurred in genes involved in oxidative stress (cat), hormonal activity (vtg1, ar), metallothionein (mt2), ER stress (bip, chop), and apoptosis (casp9). The effects were dependent on the concentrations of cationic metals in leachates. Addition of ethylenediaminetetraacetic acid protected zebrafish embryos from morphological and molecular effects. Our study suggests that metals leaching from damaged CIGS cells, may pose a potential environmental risk. PMID:26615488

  2. Effect of positive pulse charge waveforms on cycle life of nickel-zinc cells

    NASA Technical Reports Server (NTRS)

    Smithrick, J. J.

    1980-01-01

    Five amp-hour nickel-zinc cells were life cycled to evaluate four different charge methods. Three of the four waveforms investigated were 120 Hz full wave rectified sinusoidal (FWRS), 120 Hz silicon controlled rectified (SCR), and 1 kHz square wave (SW). The fourth, a constant current method, was used as a baseline of comparison. Three sealed Ni-Zn cells connected in series were cycled. Each series string was charged at an average c/20 rate, and discharged at a c/2.5 rate to a 75% rated depth. Results indicate that the relatively inexpensive 120 Hz FWRS charger appears feasible for charging 5 amp-hour nickel-zinc cells with no significant loss in average cycle life when compared to constant current charging. The 1-kHz SW charger could also be used with no significant loss in average cycle life, and suggests the possibility of utilizing the existing electric vehicle chopper controller circuitry for an on-board charger. There was an apparent difference using the 120 Hz SCR charger compared to the others, however, this difference could be due to an inadvertent severe overcharge, which occurred prior to cell failure. The remaining two positive pulse charging waveforms, FWRS and 1 kHz, did not improve the cycle life of 5 amp-hour nickel-zinc cells over that of constant current charging.

  3. November 21, 2000 PV Lesson Plan 1 Solar Cells

    E-print Network

    Oregon, University of

    November 21, 2000 PV Lesson Plan 1 ­ Solar Cells Prepared for the Oregon Million Solar Roofs High School Gary Grace ­ South Eugene High School In Schools #12;1 Solar Cells Lesson Plan Content: In this lesson, students are introduced to the basic physics and chemistry behind the operation of a solar cell

  4. Questions I will answer What is a solar cell?

    E-print Network

    McGehee, Michael

    grid 4 #12;5 #12;Solar panels on the Interna9onal Space Sta9on 6 #12;Area needed to power the country (150 km)2 of Nevada covered with 15 % efficient solar cells could provide#12;Questions I will answer · What is a solar cell? · How are solar cells

  5. EE Times: Semi News Groups claim breakthroughs in solar cells

    E-print Network

    Rogers, John A.

    claim to offer nearly twice the efficiency as silicon in solar cells. But solar cells based concentrator photovoltaic (CPV) modules for large- scale solar power generation. Semprius' microEE Times: Semi News Groups claim breakthroughs in solar cells Mark LaPedus Page 1 of 2 EE Times (05

  6. Third Working Meeting on Gallium Arsenide Solar Cells

    NASA Technical Reports Server (NTRS)

    Walker, G. H. (compiler)

    1976-01-01

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

  7. Zinc pyrithione induces cellular stress signaling and apoptosis in Hep-2 cervical tumor cells: the role of mitochondria and lysosomes.

    PubMed

    Rudolf, Emil; Cervinka, Miroslav

    2010-04-01

    Increased intracellular free zinc concentrations are associated with activation of several stress signaling pathways, specific organelle injury and final cell death. In the present work we examined the involvement of mitochondria and lysosomes and their crosstalk in free zinc-induced cell demise. We report that treatment of cervical tumor Hep-2 cells with zinc pyrithione leads to an early appearance of cytoplasmic zinc-specific foci with corresponding accumulation of zinc first in mitochondria and later in lysosomes. Concomitant with these changes, upregulation of expression of metallothionein II A gene as well as the increased abundance of its protein occurs. Moreover, zinc activates p53 and its dependent genes including Puma and Bax and they contribute to an observed loss of mitochondrial membrane potential and activation of apoptosis. Conversely, lysosomal membrane permeabilization and its promoted cleavage of Bid occurs in a delayed manner in treated cells and their effect on decrease of mitochondrial membrane potential is limited. The use of specific inhibitors as well as siRNA technology suggest a crucial role of MT-IIA in trafficking of free zinc into mitochondria or lysosomes and regulation of apoptotic or necrotic cell demise. PMID:20151177

  8. Solar energy-conversion processes in organic solar cells

    NASA Astrophysics Data System (ADS)

    Xu, Zhihua; Zang, Huidong; Hu, Bin

    2008-09-01

    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.

  9. Silicon solar cell process. Development, fabrication and analysis

    NASA Technical Reports Server (NTRS)

    Yoo, H. I.; Iles, P. A.; Tanner, D. P.

    1978-01-01

    Solar cells were fabricated from unconventional silicon sheets, and the performances were characterized with an emphasis on statistical evaluation. A number of solar cell fabrication processes were used and conversion efficiency was measured under AMO condition at 25 C. Silso solar cells using standard processing showed an average efficiency of about 9.6%. Solar cells with back surface field process showed about the same efficiency as the cells from standard process. Solar cells from grain boundary passivation process did not show any improvements in solar cell performance.

  10. Printable CIGS thin film solar cells

    NASA Astrophysics Data System (ADS)

    Fan, Xiaojuan

    2013-03-01

    Among the various thin film solar cells in the market, CuInGaSe thin film solar cells have been considered as the most promising alternatives to crystalline silicon solar cells because of their high photo-electricity conversion efficiency, reliability, and stability. However, many fabrication methods of CIGS thin film are based on vacuum processes such as evaporation and sputtering techniques which are not cost efficient. This work develops a solution method using paste or ink liquid spin-coated on glass that would be competitive to conventional ways in terms of cost effective, non-vacuum needed, and quick processing. A mixture precursor was prepared by dissolving appropriate amounts of composition chemicals. After the mixture solution was cooled, a viscous paste was prepared and ready for spin-coating process. A slight bluish CIG thin film on substrate was then put in a tube furnace with evaporation of metal Se followed by depositing CdS layer and ZnO nanoparticle thin film coating to complete a solar cell fabrication. Structure, absorption spectrum, and photo-electricity conversion efficiency for the as-grown CIGS thin film solar cell are under study.

  11. CZTSSe thin film solar cells: Surface treatments

    NASA Astrophysics Data System (ADS)

    Joglekar, Chinmay Sunil

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

  12. Black silicon for solar cell applications

    NASA Astrophysics Data System (ADS)

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

    2012-06-01

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

  13. PIAS1-modulated Smad2/4 complex activation is involved in zinc-induced cancer cell apoptosis.

    PubMed

    Yang, N; Zhao, B; Rasul, A; Qin, H; Li, J; Li, X

    2013-01-01

    Prostate cancer is one of the most frequently diagnosed cancers among men. Dietary intake of nutrients is considered crucial for preventing the initiation of events leading to the development of carcinoma. Many dietary compounds have been considered to contribute to cancer prevention including zinc, which has a pivotal role in modulating apoptosis. However, the mechanism for zinc-mediated prostate cancer chemoprevention remains enigmatic. In this study, we investigated the therapeutic effect of zinc in prostate cancer chemoprevention for the first time. Exposure to zinc induced apoptosis and resulted in transactivation of p21(WAF1/Cip1) in a Smad-dependent and p53-independent manner in prostate cancer cells. Smad2 and PIAS1 proteins were significantly upregulated resulting in dramatically increased interactions between Smad2/4 and PIAS1 in the presence of zinc in LNCaP cells. Furthermore, it was found that the zinc-induced Smad4/2/PIAS1 transcriptional complex is responsible for Smad4 binding to SBE1 and SBE3 regions within the p21(WAF1/Cip1) promoter. Exogenous expression of Smad2/4 and PIAS1 promotes zinc-induced apoptosis concomitant with Smad4 nuclear translocation, whereas endogenous Smad2/4 silencing inhibited zinc-induced apoptosis accompanying apparent p21(WAF1/Cip1) reduction. Moreover, the knockdown of PIAS1 expression attenuated the zinc-induced recruitment of Smad4 on the p21(WAF1/Cip1) promoter. The colony formation experiments demonstrate that PIAS1 and Smad2/4 silencing could attenuate zinc apoptotic effects, with a proliferation of promoting effects. We further demonstrate the correlation of apoptotic sensitivity to zinc and Smad4 and PIAS1 in multiple cancer cell lines, demonstrating that the important roles of PIAS1, Smad2, and Smad4 in zinc-induced cell death and p21(WAF1/Cip1) transactivation were common biological events in different cancer cell lines. Our results suggest a new avenue for regulation of zinc-induced apoptosis, and provide a model that demonstrates zinc endorses the Smad2/4/PIAS1 complex to activate the p21(WAF1/Cip1) gene that mediates apoptosis. PMID:24052079

  14. Method of manufacturing a solar cell panel

    SciTech Connect

    Dubois, P.

    1982-03-30

    The photovoltaic cells are retained and protected by a transparent elastomer layer extruded when hot prior to vulcanization and applied against the cells with a slight pressure to cause it to go into the spaces between cells, and vulcanized by heating, for example at 110* C. Or at 180* C., thanks to the presence of incorporated peroxides. Application in the production of electricity from solar energy.

  15. Solar Cell Efficiency Tables (Version 33)

    SciTech Connect

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

    2009-01-01

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

  16. Improved zinc electrode and rechargeable zinc-air battery

    DOEpatents

    Ross, P.N. Jr.

    1988-06-21

    The invention comprises an improved rechargeable zinc-air cell/battery having recirculating alkaline electrolyte and a zinc electrode comprising a porous foam support material which carries the active zinc electrode material. 5 figs.

  17. Large area monolithic organic solar cells

    NASA Astrophysics Data System (ADS)

    Jin, Hui; Tao, Cheng; Hambsch, Mike; Pivrikas, Almantas; Velusamy, Marappan; Aljada, Muhsen; Zhang, Yuliang; Burn, Paul L.; Meredith, Paul

    2012-11-01

    Although efficiencies of > 10% have recently been achieved in laboratory-scale organic solar cells, these competitive performance figures are yet to be translated to large active areas and geometries relevant for viable manufacturing. One of the factors hindering scale-up is a lack of knowledge of device physics at the sub-module level, particularly cell architecture, electrode geometry and current collection pathways. A more in depth understanding of how photocurrent and photovoltage extraction can be optimised over large active areas is urgently needed. Another key factor suppressing conversion efficiencies in large area cells is the relatively high sheet resistance of the transparent conducting anode - typically indium tin oxide. Hence, to replace ITO with alternative transparent conducting anodes is also a high priority on the pathway to viable module-level organic solar cells. In our paper we will focus on large area devices relevant to sub-module scales - 5 cm × 5 cm monolithic geometry. We have applied a range of experimental techniques to create a more comprehensive understanding of the true device physics that could help make large area, monolithic organic solar cells more viable. By employing this knowledge, a novel transparent anode consisting of molybdenum oxide (MoOx) and silver (Ag) is developed to replace ITO and PEDOT-free large area solar cell sub-modules, acting as both a transparent window and hole-collecting electrode. The proposed architecture and anode materials are well suited to high throughput, low cost all-solution processing.

  18. A study of ZnO:B films for thin film silicon solar cells

    NASA Astrophysics Data System (ADS)

    Yin, J.; Zhu, H.; Wang, Y.; Wang, Z.; Gao, J.; Mai, Y.; Ma, Y.; Wan, M.; Huang, Y.

    2012-10-01

    Boron doped zinc oxide (ZnO:B) films with different thicknesses were prepared with low pressure chemical vapor deposition (LPCVD) technique and implemented in thin film silicon solar cells as front and back electrodes. It is found that thick back ZnO:B film electrode in thin film silicon solar cells leads to a high fill factors (FF), which is attributed to an improvement of the electrical properties of the thick ZnO:B films, and in the meanwhile a slightly low short circuit currents (Jsc) due to a high light absorption in the thick back ZnO:B films. Differently, the thicker front ZnO:B film electrodes result in a high Jsc but a low FF of solar cells compared to the thinner ones. The low FF of the solar cells may be caused by the local shunt originated from the pinholes or by the cracks (zones of non-dense material) formed in particular in microcrystalline silicon materials deposited on rough front ZnO:B films. As to the high Jsc, it is expected to be due to a good light trapping effect inside solar cells grown on rough front ZnO:B films. Moreover, the application of high reflective polyvinyl butyral (PVB) foils effectively enhances the utilization of incident light in solar cells. By optimizing deposition process of the ZnO:B films, high efficiencies of 8.8% and 10% for single junction thin film amorphous silicon solar cells (a-Si:H, intrinsic layer thickness < 200 nm) and amorphous/microcrystalline silicon tandem solar cells (a-Si:H/?c-Si:H, intrinsic amorphous silicon layer thickness < 220 nm), respectively, are achieved.

  19. Fabricating solar cells with silicon nanoparticles

    DOEpatents

    Loscutoff, Paul; Molesa, Steve; Kim, Taeseok

    2014-09-02

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

  20. Nanophotonic front electrodes for perovskite solar cells

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  1. Plasmonic ITO-free polymer solar cell.

    PubMed

    Lin, Ming-Yi; Kang, Yu Ling; Chen, Yu-Cheng; Tsai, Tsung-Han; Lin, Shih-Chieh; Huang, Yi-Hsiang; Chen, Yi-Jiun; Lu, Chun-Yang; Lin, Hoang Yan; Wang, Lon A; Wu, Chung-Chih; Lee, Si-Chen

    2014-03-10

    The aluminum and sliver multilayered nano-grating structure is fabricated by laser interference lithography and the intervals between nanoslits is filled with modified PEDOT:PSS. The grating structured transparent electrode functions as the anti-reflection layer which not only decreases the reflected light but also increases the absorption of the active layer. The performances of P3HT:PC??BM solar cells are studied experimentally and theoretically in detail. The field intensities of the transverse magnetic (TM) and transverse electrical (TE) waves distributed in the active layer are simulated by rigorous coupled wave analysis (RCWA). The power conversion efficiency of the plasmonic ITO-free polymer solar cell can reach 3.64% which is higher than ITO based polymer solar cell with efficiency of 3.45%. PMID:24922253

  2. Material requirements for a boron phosphide thermal neutron counter

    SciTech Connect

    Viles, T.P.; Brunett, B.A.; Yoon, H.

    1998-12-31

    Electrical characterization (current versus voltage and capacitance versus voltage) of nonstoichiometric amorphous boron phosphide Schottky diodes for neutron detection is presented. These results are incorporated in a Monte Carlo model of detector response to determine material requirements for a boron phosphide neutron counter.

  3. Microwave-assisted synthesis of transition metal phosphide

    SciTech Connect

    Viswanathan, Tito

    2014-12-30

    A method of synthesizing transition metal phosphide. In one embodiment, the method has the steps of preparing a transition metal lignosulfonate, mixing the transition metal lignosulfonate with phosphoric acid to form a mixture, and subjecting the mixture to a microwave radiation for a duration of time effective to obtain a transition metal phosphide.

  4. Gaalas/Gaas Solar Cell Process Study

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

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

  5. I-III-VI.sub.2 based solar cell utilizing the structure CuInGaSe.sub.2 CdZnS/ZnO

    DOEpatents

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

    1992-01-07

    A thin film I-III-VI.sub.2 based solar cell having a first layer of copper indium gallium selenide, a second layer of cadmium zinc sulfide, a double layer of zinc oxide, and a metallization structure comprised of a layer of nickel covered by a layer of aluminum. An optional antireflective coating may be placed on said metallization structure. The cadmium zinc sulfide layer is deposited by means of an aqueous solution growth deposition process and may actually consist of two layers: a low zinc content layer and a high zinc content layer. Photovoltaic efficiencies of 12.5% at Air Mass 1.5 illumination conditions and 10.4% under AMO illumination can be achieved.

  6. Space solar cell research - Problems and potential

    NASA Technical Reports Server (NTRS)

    Flood, Dennis J.

    1986-01-01

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

  7. Multi-junction solar cell device

    DOEpatents

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

    2007-12-18

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

  8. Solar cell contact formation using laser ablation

    SciTech Connect

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

    2015-07-21

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

  9. High performance polymer tandem solar cell

    PubMed Central

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

    2015-01-01

    A power conversion efficiency of 9.02% is obtained for a fully solution-processed polymer tandem solar cell, based on the diketopyrrolopyrrole unit polymer as a low bandgap photoactive material in the rear subcell, in conjunction with a new robust interconnecting layer. This interconnecting layer is optically transparent, electrically conductive, and physically strong, thus, the charges can be collected and recombined in the interconnecting layer under illumination, while the charge is generated and extracted under dark conditions. This indicates that careful interface engineering of the charge-carrier transport layer is a useful approach to further improve the performance of polymer tandem solar cells. PMID:26669577

  10. High performance polymer tandem solar cell.

    PubMed

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

    2015-01-01

    A power conversion efficiency of 9.02% is obtained for a fully solution-processed polymer tandem solar cell, based on the diketopyrrolopyrrole unit polymer as a low bandgap photoactive material in the rear subcell, in conjunction with a new robust interconnecting layer. This interconnecting layer is optically transparent, electrically conductive, and physically strong, thus, the charges can be collected and recombined in the interconnecting layer under illumination, while the charge is generated and extracted under dark conditions. This indicates that careful interface engineering of the charge-carrier transport layer is a useful approach to further improve the performance of polymer tandem solar cells. PMID:26669577

  11. High throughput solar cell ablation system

    DOEpatents

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

    2014-10-14

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

  12. Solar cell contact formation using laser ablation

    DOEpatents

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

    2014-07-22

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

  13. High throughput solar cell ablation system

    DOEpatents

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

    2012-09-11

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

  14. Origami-enabled deformable silicon solar cells

    SciTech Connect

    Tang, Rui; Huang, Hai; Liang, Hanshuang; Liang, Mengbing; Tu, Hongen; Xu, Yong; Song, Zeming; Jiang, Hanqing; Yu, Hongyu

    2014-02-24

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

  15. Oxide heterostructures for ecient solar cells

    SciTech Connect

    Assmann, E.; Blaha, P.; Laskowski, R; Held, K.; Okamoto, Satoshi; Sangiovanni, G.

    2013-01-01

    We propose an unexplored class of absorbing materials for high-efficiency solar cells: heterostructures of transition-metal oxides. In particular, LaVO3 grown on SrTiO3 has a direct band gap ~1.1 eV in the optimal range as well as an internal potential gradient, which can greatly help to separate the photogenerated electron-hole pairs. Furthermore, oxide heterostructures afford the flexibility to combine LaVO3 with other materials such as LaFeO3 in order to achieve even higher efficiencies with band-gap graded solar cells. We use density-functional theory to demonstrate these features.

  16. Design and fabrication of solar cell modules

    NASA Technical Reports Server (NTRS)

    Shaughnessy, T. P.

    1978-01-01

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

  17. Solar cell contact formation using laser ablation

    DOEpatents

    Harley, Gabriel; Smith, David; Cousins, Peter

    2012-12-04

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

  18. Solar heating of GaAs nanowire solar cells.

    PubMed

    Wu, Shao-Hua; Povinelli, Michelle L

    2015-11-30

    We use a coupled thermal-optical approach to model the operating temperature rise in GaAs nanowire solar cells. We find that despite more highly concentrated light absorption and lower thermal conductivity, the overall temperature rise in a nanowire structure is no higher than in a planar structure. Moreover, coating the nanowires with a transparent polymer can increase the radiative cooling power by 2.2 times, lowering the operating temperature by nearly 7 K. PMID:26698787

  19. Optimization of Organic Solar Cells: Materials, Devices and Interfaces

    NASA Astrophysics Data System (ADS)

    Zhou, Nanjia

    Due to the increasing demand for sustainable clean energy, photovoltaic cells have received intensified attention in the past decade in both academia and industry. Among the types of cells, organic photovoltaic (OPV) cells offer promise as alternatives to conventional inorganic-type solar cells owning to several unique advantages such as low material and fabrication cost. To maximize power conversion efficiencies (PCEs), extensive research efforts focus on frontier molecular orbital (FMO) energy engineering of photoactive materials. Towards this objective, a series of novel donor polymers incorporating a new building block, bithiophene imide (BTI) group are developed, with narrow bandgap and low-lying highest occupied molecular orbital (HOMO) energies to increase short circuit current density, Jsc, and open circuit voltage, Voc.. Compared to other PV technologies, OPVs often suffer from large internal recombination loss and relatively low fill factors (FFs) <70%. Through a combination of materials design and device architecture optimization strategies to improve both microscopic and macroscopic thin film morphology, OPVs with PCEs up to 8.7% and unprecedented FF approaching 80% are obtained. Such high FF are close to those typically achieved in amorphous Si solar cells. Systematic variations of polymer chemical structures lead to understanding of structure-property relationships between polymer geometry and the resulting blend film morphology characteristics which are crucial for achieving high local mobilities and long carrier lifetimes. Instead of using fullerene as the acceptors, an alternative type of OPV is developed employing a high electron mobility polymer, P(NDI2OD-T2), as the acceptor. To improve the all-polymer blend film morphology, the influence of basic solvent properties such as solvent boiling point and solubility on polymer phase separation and charge transport properties is investigated, yielding to a high PCE of 2.7% for all-polymer solar cells. To take advantages of the inherent mechanical flexibility associated with organic materials, the development of transparent, flexible substrates to replace the conventionally used polycrystalline ITO electrodes is highly desirable. Employing an ultraflexible amorphous zinc indium tin oxide (a-ZITO) transparent conducting oxide (TCO), highly efficient OPVs with similar PCEs to rigid ones are obtained. Furthermore, these cells show no significant PCE reduction under controlled bending test.

  20. Visualization of calcium and zinc ions in Saccharomyces cerevisiae cells treated with PEFs (pulse electric fields) by laser confocal microscopy.

    PubMed

    Urszula, Pankiewicz; Jerzy, Jamroz; Sujka, Monika; Kowalski, Rados?aw

    2015-12-01

    The aim of the present work was to visualize the areas of increased concentration of calcium and zinc ions inside Saccharomyces cerevisiae cells with the use of confocal microscopy and to make an attempt to asses semi-quantitatively their concentration within the limits of the cells. Semi-quantitative analysis revealed that fluorescence inside cells from control samples was three-times lower than that observed for cells from the sample enriched with calcium. Differences in distribution of fluorescence intensity between cells originated from the samples enriched with zinc and control samples were also observed. On the basis of the optical sections, the 3D reconstructions of ion-rich areas distribution in the cell were made. The obtained results showed that confocal microscopy is a useful technique for visualization of the areas in S. cerevisiae cells which contain higher amount of calcium and zinc and it may be also used for semi-quantitative analysis. PMID:26041158

  1. Printable CIGS thin film solar cells

    NASA Astrophysics Data System (ADS)

    Fan, Xiaojuan

    2014-03-01

    Among the various thin film solar cells in the market, CuInGaSe thin film cells have been considered as the most promising alternatives to silicon solar cells because of their high photo-electricity efficiency, reliability, and stability. However, many fabrication of CIGS thin film are based on vacuum processes such as evaporation sputtering techniques which are not cost efficient. This work develops a method using paste or ink liquid spin-coated on glass that would be to conventional ways in terms of cost effective, non-vacuum needed, quick processing. A mixture precursor was prepared by dissolving appropriate amounts of chemicals. After the mixture solution was cooled, a viscous paste prepared and ready for spin-coating process. A slight bluish CIG thin film substrate was then put in a tube furnace with evaporation of metal Se by depositing CdS layer and ZnO nanoparticle thin film coating to a solar cell fabrication. Structure, absorption spectrum, and photo-conversion efficiency for the as-grown CIGS thin film solar cell under study.

  2. Advances in large area polycrystalline solar cells

    NASA Technical Reports Server (NTRS)

    Vendura, G. J., Jr.; Johnson, G.; Hoelscher, J. F.

    1984-01-01

    Polycrystaline silicon is presently routinely processed into low cost 10 cm by 10 cm solar cells. However assuming minimal handling difficulties, only minor equipment modifications and no increase in processing complexity, the fabrication of even larger geometries would be economically advantageous. This investigation addressed the feasibility of developing 10 cm by 15 cm solar cells from research through pilot line production stages. The major thrust was to minimize costing by using existing production equipment and proven techniques wherever possible. Accordingly methods were developed to section larger substrates from existing cast ingots, a simple solar cell was designed and low cost processes implemented. After numerous preliminary experiments, pilot line production of 1500 cells was completed. Of these approximately 62 percent exhibited efficiencies greater than 7.0 percent, 53 percent were greater than 8.0 percent and 15 percent were greater than 9.0 percent. Based on this study, the regular production of 10 cm by 15 cm solar cells was determined to be both feasible and cost effective using existing processing methods.

  3. Plastic solar cells with engineered interfaces

    NASA Astrophysics Data System (ADS)

    Guo, Xugang; Marks, Tobin J.

    2013-03-01

    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.

  4. Electrical overstress failure in silicon solar cells

    SciTech Connect

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

    1982-11-01

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

  5. Electrical overstress failure in silicon solar cells

    NASA Astrophysics Data System (ADS)

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

    1982-11-01

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

  6. Plastic Schottky barrier solar cells

    DOEpatents

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

    1984-01-24

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

  7. High efficiency ultrathin silicon solar cells

    NASA Technical Reports Server (NTRS)

    Storti, G.; Wrigley, C. Y.

    1979-01-01

    This paper summarizes developments in ultrathin, (50 micron), silicon solar cells for high power-to-weight ratio space power systems. The fabrication technology developments included uniformly thinning oriented silicon slices, enhancement of internal reflection, optimizing high-temperature processes, surface texturing and back surface field enhancement. The best textured-surface ultrathin cells have achieved 14.3% AMO efficiency, while pilot-manufacturing quantities of smooth-surfaced cells have been fabricated with efficiencies of 12%. Data are presented on cell structure, fabrication collection efficiencies and optical properties.

  8. A low-cost, high-performance zinc-hydrogen peroxide fuel cell

    NASA Astrophysics Data System (ADS)

    An, L.; Zhao, T. S.; Zhou, X. L.; Yan, X. H.; Jung, C. Y.

    2015-02-01

    Electric vehicles (EVs) are primarily limited by the distance they can travel, charge time and cost. Here we report a catalyst-free, high-performance zinc-hydrogen peroxide fuel cell that consists of a redox flow cell with the respective redox couple at the anode (V(II)/V(III)) and cathode (V(IV)/V(V)) regenerated by the fuel (zinc) and the oxidant (hydrogen peroxide). Unlike batteries that have low capacities and need to be frequently charged, the present fuel cell enables future vehicles to travel farther distances on one charge and almost instantaneous charge time. More importantly, it is demonstrated that this novel fuel cell exhibits an extraordinarily high peak power density of 1192 mW cm-2 at 60 °C, a performance which is about five times higher than that of state-of-the-art conventional fuel cells of the kind (265 mW cm-2). Another striking feature of the present fuel cell is that it does not require catalysts, allowing the power pack to be both cost-effective and durable. These important features make the present fuel cell a promising post lithium-ion technology, opening a sustainable way to propel next-generation vehicles.

  9. Preparation of anisotropic transition metal phosphide nanocrystals: the case of nickel phosphide nanoplatelets, nanorods, and nanowires.

    PubMed

    She, Houde; Chen, Yuanzhi; Luo, Xiaohua; Yue, Guang-Hui; Peng, Dong-Liang

    2010-08-01

    We have synthesized anisotropic nickel phosphide nanocrystals, including triangular/hexagonal nanoplatelets, nanorods and nanowires, via a solution-phase synthetic method that uses nickel(II) acetylacetonate as a metal precursor and trioctylphosphine as a phosphorus source. Nickel phosphide nanoplatelets have been prepared from a one-pot reaction, and their dimensions in the length mostly vary from 20 to 50 nm, while their thicknesses are in a narrow range of 7-9 nm. Nickel phosphide nanorods with a width of approximately 6 nm and a typical length of 25-32 nm can be synthesized from either the one-pot reaction or the multi-injection approach, although the latter can generate nanorods with a much higher uniformity. A continuous injection approach has been used to synthesize nanowires that have a typical width of approximately 6 nm and a length ranging from tens of nanometers up to several hundred nanometers. Major factors that influence the growth of nickel phosphide nanocrystals have been investigated, and a multi-surfactant system is found to be essential for the formation of anisotropic nanostructure. Magnetic studies have revealed paramagnetic characteristics for all the synthesized samples. PMID:21125867

  10. Direct-Write Contacts for Solar Cells

    SciTech Connect

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

    2005-01-01

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

  11. Hot electron plasmon-protected solar cell.

    PubMed

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

    2015-09-21

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

  12. Studies of silicon pn junction solar cells

    NASA Technical Reports Server (NTRS)

    Lindholm, F. A.; Neugroschel, A.

    1977-01-01

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

  13. Center punched solar cell module development effort

    NASA Technical Reports Server (NTRS)

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

    1978-01-01

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

  14. Fabrication, performance and atmospheric stability of inverted ZnO nanoparticle/polymer solar cell

    NASA Astrophysics Data System (ADS)

    Yuan, Zhaolin

    2015-01-01

    Zinc oxide (ZnO) nanoparticles (NPs, ~5 nm) were first synthesized by a simple wet chemical method. A mixture of poly(3-hexylthiophene-2,5-diyl):(6,6)-phenyl C61 butyric acid methyl ester (P3HT:PCBM) was used as the photoactive layer, and an inverted solar cell with a structure of ITO/ZnO NPs/P3HT:PCBM/MoO3/Ag was fabricated. Its performance and stability in the ambient atmosphere were investigated in detail. The results showed that the fabricated solar cell under 100 mW/cm2 AM1.5 illumination exhibited a power conversion efficiency (PCE) of 0.28 %. In addition, illumination intensity had significant effect on open circuit voltage ( V oc), short circuit current ( J sc), fill factor (FF), and PCE of the fabricated solar cell. The dark storability (darkness, room temperature, and 50-60 % relative humidity) was shown to exceed 4,416 h without notable loss in PCE. The fabricated solar cell with excellent long-term stability was achieved in an ambient atmosphere; also, the stable mechanism of the solar cell in the ambient atmosphere was illuminated.

  15. Flexible plastic solar cells offer great advantages when compared with

    E-print Network

    Langendoen, Koen

    Flexible plastic solar cells offer great advantages when compared with traditional silicon solar for a solar cell: extremely easy to produce, very cheap and with good perspectives for high efficiencies. Since ten years considerable progress has been made in developing new and very promising types of solar

  16. Space solar cell technology development - A perspective

    NASA Technical Reports Server (NTRS)

    Scott-Monck, J.

    1982-01-01

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

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

    NASA Technical Reports Server (NTRS)

    1977-01-01

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

  18. Bandgap tuning of multiferroic oxide solar cells

    NASA Astrophysics Data System (ADS)

    Nechache, R.; Harnagea, C.; Li, S.; Cardenas, L.; Huang, W.; Chakrabartty, J.; Rosei, F.

    2015-01-01

    Multiferroic films are increasingly being studied for applications in solar energy conversion because of their efficient ferroelectric polarization-driven carrier separation and above-bandgap generated photovoltages, which in principle can lead to energy conversion efficiencies beyond the maximum value (˜34%) reported in traditional silicon-based bipolar heterojunction solar cells. However, the efficiency reported so far is still too low (<2%) to be considered for commercialization. Here, we demonstrate a new approach to effectively tune the bandgap of double perovskite multiferroic oxides by engineering the cationic ordering for the case of Bi2FeCrO6. Using this approach, we report a power conversion efficiency of 8.1% under AM 1.5?G irradiation (100?mW?cm-2) for Bi2FeCrO6 thin-film solar cells in a multilayer configuration.

  19. Piezoresistance and solar cell efficiency

    NASA Technical Reports Server (NTRS)

    Weizer, Victor G.

    1987-01-01

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

  20. Basic mechanisms governing solar-cell efficiency

    NASA Technical Reports Server (NTRS)

    Lindholm, F. A.; Neugroschel, A.; Sah, C. T.

    1976-01-01

    The efficiency of a solar cell depends on the material parameters appearing in the set of differential equations that describe the transport, recombination, and generation of electrons and holes. This paper describes the many basic mechanisms occurring in semiconductors that can control these material parameters.