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. Performance Enhancement of a Graphene-Zinc Phosphide Solar Cell Using the Electric Field-Effect

    E-print Network

    Javey, Ali

    Performance Enhancement of a Graphene-Zinc Phosphide Solar Cell Using the Electric Field States Electrical Engineering and Computer Sciences, University of California, Berkeley, California for photovoltaics. We present a field-effect solar cell using graphene to form a tunable junction barrier

  3. Indium phosphide solar cells

    NASA Technical Reports Server (NTRS)

    Weinberg, Irving

    1991-01-01

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

  4. Wide Band Gap Gallium Phosphide Solar Cells

    Microsoft Academic Search

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

    2012-01-01

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

  5. Indium phosphide solar cells for laser power beaming applications

    Microsoft Academic Search

    Raj K. Jain; Geoffrey A. Landis

    1992-01-01

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

  6. 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.

  7. Status of indium phosphide solar cell development at Spire

    NASA Technical Reports Server (NTRS)

    Spitzer, M. B.; Keavney, C. J.; Vernon, S. M.

    1987-01-01

    On-going development of indium phosphide solar cells for space applications is presented. The development is being carried out with a view towards both high conversion efficiency and simplicity of manufacture. The cell designs comprise the ion-implanted cell, the indium tin oxide top contact cell, and the epitaxial cell grown by metal organic chemical vapor deposition. Modelling data on the limit to the efficiency are presented and comparison is made to measured performance data.

  8. 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.

  9. 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

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

    Microsoft Academic Search

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

    2010-01-01

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

  11. Recent developments in indium phosphide space solar cell research

    NASA Technical Reports Server (NTRS)

    Brinker, David J.; Weinberg, Irving

    1987-01-01

    Recent developments and progress in indium phosphide solar cell research for space application are reviewed. Indium phosphide homojunction cells were fabricated in both the n+p and p+n configurations with total area efficiencies of 17.9 and 15.9% (air mass 0 and 25 C) respectively. Organometallic chemical vapor deposition, liquid phase epitaxy, ion implantation and diffusion techniques were employed in InP cell fabrication. A theoretical model of a radiation tolerant, high efficiency homojunction cell was developed. A realistically attainable AMO efficiency of 20.5% was calculated using this model with emitter and base doping of 6 x 10 to the 17th power and 5 x 10 the the 16th power/cu cm respectively. Cells of both configurations were irradiated with 1 MeV electrons and 37 MeV protons. For both proton and electron irradiation, the n+p cells are more radiation resistant at higher fluences than the p+n cells. The first flight module of four InP cells was assembled for the Living Plume Shield III satellite.

  12. Recent developments in indium phosphide space solar cell research

    NASA Technical Reports Server (NTRS)

    Brinker, David J.; Weinberg, Irving

    1987-01-01

    Recent developments and progress in indium phosphide solar cell research for space application are reviewed. Indium phosphide homojunction cells were fabricated in both the n + p and p + n configurations with total area efficiencies of 17.9 and 15.9 percent (air mass 0 and 25 C) respectively. Organometallic chemical vapor deposition, liquid phase epitaxy, ion implantation and diffusion techniques were employed in InP cell fabrication. A theoretical model of a radiation tolerant, high efficiency homojunction cell was developed. A realistically attainable AM0 efficiency of 20.5 percent was calculated using this model with emitter and base doping of 6 x 10 to the 17th power and 5 x 10 to the 16th power/cu cm, respectively. Cells of both configurations were irradiated with 1 MeV electrons and 37 MeV protons. For both proton and electron irradiation, the n + p cells are more radiation resistant at higher fluences than the p + n cells. The first flight module of four InP cells was assembled for the Living Plume Shield III satellite.

  13. 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.

  14. Progress in indium phosphide solar cell research

    NASA Technical Reports Server (NTRS)

    Weinberg, Irving; Swartz, Clifford K.; Hart, R. E., Jr.

    1989-01-01

    Progress, dating from the start of the Lewis program, is reviewed emphasizing processing techniques which have achieved the highest efficiencies in a given year. To date, the most significant achievement has been attainment of AM0 total area efficiencies approaching 19 percent. Although closed tube diffusion is not considered to be an optimum process, reasonably efficient 2cm x 2cm and 1cm x 2cm InP cells have been produced in quantity by this method with a satellite to be launched in 1990 using these cells. Proton irradiation of these relatively large area cells indicates radiation resistance comparable to that previously reported for smaller InP cells. A similar result is found for the initial proton irradiations of ITO/InP cells processed by D. C. sputtering. With respect to computer modelling, a comparison of n/p homojunction InP and GaAs cells of identical geometries and dopant concentrations has confirmed the superior radiation resistance of InP cells under 1 MeV electron irradiations.

  15. 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.

  16. 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....

  17. Indium phosphide solar cells - Recent developments and estimated performance in space

    NASA Technical Reports Server (NTRS)

    Weinberg, Irving; Brinker, David J.

    1990-01-01

    The current status of indium phosphide solar cell research is reviewed. In the NASA research program, efficiencies of 18.8 percent were achieved for standard n/p homojunction InP cells while 17 percent was achieved for ITO/InP cells processed by sputtering n-type indium tin oxide onto p-type indium phosphide. The latter represents a cheaper, simpler processing alternative. Computer modeling calculations indicate that efficiencies of over 21 percent are feasible. Relatively large area cells are produced in Japan with a maximum efficiency of 16.6 percent.

  18. INDIUM PHOSPHIDE WINDOW LAYERS FOR INDIUM GALLIUM ARSENIDE SOLAR CELLS

    Microsoft Academic Search

    Raj K. Jain

    Window layers help in reducing the surface recombination at the emitter surface of the solar cells re- sulting in significant improvement in energy conversion efficiency. Indium gallium arsenide (InxGa1-xAs) 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

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

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

  20. 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.

  1. Comparative radiation resistance, temperature dependence and performance of diffused junction indium phosphide solar cells

    NASA Technical Reports Server (NTRS)

    Weinberg, I.; Swartz, C. K.; Hart, R. E., Jr.; Ghandhi, S. K.; Borrego, J. M.

    1987-01-01

    Indium phosphide solar cells whose p-n junctions were processed by the open tube capped diffusion and by the closed tube uncapped diffusion of sulfur into Czochralski-grown p-type substrates are compared. Differences found in radiation resistance were attributed to the effects of increased base dopant concentration. Both sets of cells showed superior radiation resistance to that of gallium arsenide cells, in agreement with previous results. No correlation was, however, found between the open-circuit voltage and the temperature dependence of the maximum power.

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

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

    Metalorganic 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 (greaater than 16 percent AM0) 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 AM0 efficiency at 25 C.

  3. 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.

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

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Zinc phosphide; tolerances for residues...FOOD Specific Tolerances § 180.284 Zinc phosphide; tolerances for residues...resulting from the use of the rodenticide zinc phosphide in or on the raw...

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

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Zinc phosphide; tolerances for residues...FOOD Specific Tolerances § 180.284 Zinc phosphide; tolerances for residues...resulting from the use of the rodenticide zinc phosphide in or on the raw...

  6. 40 CFR 180.284 - Zinc phosphide; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Zinc phosphide; tolerances for residues...FOOD Specific Tolerances § 180.284 Zinc phosphide; tolerances for residues...resulting from the use of the rodenticide zinc phosphide in or on the raw...

  7. 40 CFR 180.284 - Zinc phosphide; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Zinc phosphide; tolerances for residues...FOOD Specific Tolerances § 180.284 Zinc phosphide; tolerances for residues...resulting from the use of the rodenticide zinc phosphide in or on the raw...

  8. Modelling and design of high performance indium phosphide solar cells

    NASA Technical Reports Server (NTRS)

    Rhoads, Sandra L.; Barnett, Allen M.

    1989-01-01

    A first principles pn junction device model has predicted new designs for high voltage, high efficiency InP solar cells. Measured InP material properties were applied and device parameters (thicknesses and doping) were adjusted to obtain optimal performance designs. Results indicate that p/n InP designs will provide higher voltages and higher energy conversion efficiencies than n/p structures. Improvements to n/p structures for increased efficiency are predicted. These new designs exploit the high absorption capabilities, relatively long diffusion lengths, and modest surface recombination velocities characteristic of InP. Predictions of performance indicate achievable open-circuit voltage values as high as 943 mV for InP and a practical maximum AM0 efficiency of 22.5 percent at 1 sun and 27 C. The details of the model, the optimal InP structure and the effect of individual parameter variations on device performance are presented.

  9. Potential for use of indium phosphide solar cells in the space radiation environment

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    Indium phosphide solar cells were observed to have significantly higher radiation resistance than either GaAs or Si after exposure to 10 MeV proton irradiation data and previous 1 MeV electron data together with projected efficiencies for InP, it was found that these latter cells produced more output power than either GaAs or Si after specified fluences of 10 MeV protons and 1 MeV electrons. Estimates of expected performance in a proton dominated space orbit yielded much less degradation for InP when compared to the remaining two cell types. It was concluded that, with additional development to increase efficiency, InP solar cells would perform significantly better than either GaAs or Si in the space radiation environment.

  10. Indium phosphide solar cells: status and prospects for use in space

    NASA Technical Reports Server (NTRS)

    Weinberg, I.; Brinker, D. J.

    1986-01-01

    The current status of indium phosphide cell research is reviewed and state of the art efficiencies compared to those of GaAs and Si. It is shown that the radiation resistance of InP cells is superior to that of either GaAs or Si under 1 MeV electron and 10 MeV proton irradiation. Using lightweight blanket technology, a SEP array structure and projected cell efficiencies, array specific powers are obtained for all three cell types. Array performance is calculated as a function of time in orbit. The results indicate that arrays using InP cells can outperform those using GaAs or Si in orbits where radiation is a significant cell degradation factor. It is concluded that InP solar cells are excellent prospects for future use in the space radiation environment.

  11. Indium phosphide solar cells - Status and prospects for use in space

    NASA Technical Reports Server (NTRS)

    Weinberg, I.; Brinker, D. J.

    1986-01-01

    The current status of indium phosphide cell research is reviewed and state of the art efficiencies compared to those of GaAs and Si. It is shown that the radiation resistance of InP cells is superior to that of either GaAs or Si under 1 MeV electron and 10 MeV proton irradiation. Using lightweight blanket technology, a SEP array structure and projected cell efficiencies, array specific powers are obtained for all three cell types. Array performance is calculated as a function of time in orbit. The results indicate that arrays using InP cells can outperform those using GaAs or Si in orbits where radiation is a significant cell degradation factor. It is concluded that InP solar cells are excellent prospects for future use in the space radiation environment.

  12. High-efficiency indium tin oxide/indium phosphide solar cells

    NASA Technical Reports Server (NTRS)

    Li, X.; Wanlass, M. W.; Gessert, T. A.; Emery, K. A.; Coutts, T. J.

    1989-01-01

    Improvements in the performance of indium tin oxide (ITO)/indium phosphide solar cells have been realized by the dc magnetron sputter deposition of n-ITO onto an epitaxial p/p(+) structure grown on commercial p(+) bulk substrates. The highest efficiency cells were achieved when the surface of the epilayer was exposed to an Ar/H2 plasma before depositing the bulk of the ITO in a more typical Ar/O2 plasma. With H2 processing, global efficiencies of 18.9 percent were achieved. It is suggested that the excellent performance of these solar cells results from the optimization of the doping, thickness, transport, and surface properties of the p-type base, as well as from better control over the ITO deposition procedure.

  13. Annealing of defect sites in radiation damaged indium phosphide solar cells through laser illumination. Master`s thesis

    Microsoft Academic Search

    1995-01-01

    This thesis reports the results of a laser annealing technique used to remove defect sites from radiation damaged indium phosphide diffused junction solar cells. This involves the illumination of damaged solar cells with a continuous wave laser to produce a moderate heating and a large forward-biased current. The InP cells were irradiated with 27 MeV electrons to a given fluence,

  14. Process Development of Gallium Nitride Phosphide Core-Shell Nanowire Array Solar Cell

    NASA Astrophysics Data System (ADS)

    Chuang, Chen

    Dilute Nitride GaNP is a promising materials for opto-electronic applications due to its band gap tunability. The efficiency of GaNxP1-x /GaNyP1-y core-shell nanowire solar cell (NWSC) is expected to reach as high as 44% by 1% N and 9% N in the core and shell, respectively. By developing such high efficiency NWSCs on silicon substrate, a further reduction of the cost of solar photovoltaic can be further reduced to 61$/MWh, which is competitive to levelized cost of electricity (LCOE) of fossil fuels. Therefore, a suitable NWSC structure and fabrication process need to be developed to achieve this promising NWSC. This thesis is devoted to the study on the development of fabrication process of GaNxP 1-x/GaNyP1-y core-shell Nanowire solar cell. The thesis is divided into two major parts. In the first parts, previously grown GaP/GaNyP1-y core-shell nanowire samples are used to develop the fabrication process of Gallium Nitride Phosphide nanowire solar cell. The design for nanowire arrays, passivation layer, polymeric filler spacer, transparent col- lecting layer and metal contact are discussed and fabricated. The property of these NWSCs are also characterized to point out the future development of Gal- lium Nitride Phosphide NWSC. In the second part, a nano-hole template made by nanosphere lithography is studied for selective area growth of nanowires to improve the structure of core-shell NWSC. The fabrication process of nano-hole templates and the results are presented. To have a consistent features of nano-hole tem- plate, the Taguchi Method is used to optimize the fabrication process of nano-hole templates.

  15. Gallium phosphide epitaxial films for silicon-based multi-junction solar cells grown by liquid phase epitaxy

    Microsoft Academic Search

    Susan R. Huang; Xuesong Lu; A. Barnett; R. L. Opila

    2010-01-01

    The growth of thin layers of III-V semiconductors on a silicon platform for multijunction solar cell applications has the benefits of reduced materials cost and standing on the well-developed silicon integrated circuit and solar cell technology. A prime candidate for developing such a platform is gallium phosphide (GaP) because it has a 0.37% lattice mismatch with Si which is favorable

  16. 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.

  17. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-01-01

    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 POCl3 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 Voc. 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.

  19. 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.

  20. Anthraquinone repellent to reduce take of non-target birds from zinc phosphide rodenticide applications

    Microsoft Academic Search

    Scott J. Werner; Shelagh K. Tupper; Susan E. Pettit; James C. Carlson; George M. Linz

    We evaluated anthraquinone as an avian repellent to reduce take of non-target birds from zinc phosphide rodenticide applications. We observed zero mortalities and no overt signs of zinc phosphide toxicosis among 20 Canada geese (Branta canadensis), 24 horned larks (Eremophila alpestris), and 47 ring-necked pheasants (Phasianus colchicus) offered baits treated with 1% or 2% anthraquinone and 2% zinc phosphide (target

  1. Efficacy of Zinc Phosphide and Strychnine for Black-tailed Prairie Dog Control

    Microsoft Academic Search

    DANIEL W. URESK; RUDY M. KING; RAYMOND L. LINDER

    1986-01-01

    Three rodenticide treatments, zinc phosphid e(prebaited) and strychnine (both with and without prebait) ,were evaluated immediately following treatment for efficacy of controlling black- tailed prairie dogs in western South Dakota. Active prairie dog burrows were reduced 95% with zinc phosphide, 83% with strychnine (prebaited), and 45% with strychnine without prebait. Zinc phosphide was the most effective in reducing active burrows

  2. Annealing of defect sites in radiation damaged indium phosphide solar cells through laser illumination. Master`s thesis

    SciTech Connect

    Chase, C.T.

    1995-12-01

    This thesis reports the results of a laser annealing technique used to remove defect sites from radiation damaged indium phosphide diffused junction solar cells. This involves the illumination of damaged solar cells with a continuous wave laser to produce a moderate heating and a large forward-biased current. The InP cells were irradiated with 27 MeV electrons to a given fluence, and tested for degradation. Light from an argon laser was used to illuminate each cell with an irradiance of 2.5 W/sq cm, producing a current density 7 to 10 times larger than under AMO conditions. Cells were annealed at 48.5 deg C, 60 deg C, and 75 deg C for periods of 15 to 60 minutes, and cooled to 25 deg C for power recovery determination. Annealing at 48.5 deg C resulted in a recovery of 17 to 18% of the power lost due to irradiation, and annealing cells at 60 deg C produced a recovery of 43 to 48%. A single test of the technique at 75 deg C produced a net recovery of only 21% of the power lost. These results indicate that significant power recovery results from the annealing of defects within InP solar cells. Continuing research should involve the repeating of the test at 75 deg C, and irradiations with electrons or protons of energies expected in the space environment.

  3. Quantum efficiency model driven design for wide band gap gallium phosphide solar cells

    Microsoft Academic Search

    Xuesong Lu; Martin Diaz; Nicole Kotulak; Robert L. Opila; Allen Barnett

    2011-01-01

    The wide band gap of GaP (2.26eV) makes it a very good candidate for the top junction solar cell in a multi-junction solar cell system. A wide band gap solar cell can increase the efficiency of the system by absorbing and converting the high energy photons more efficiently. Quantum efficiency (QE) is a powerful tool in analyzing the solar cell's

  4. 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.

  5. Indium phosphide solar cell research in the United States: Comparison with non-photovoltaic 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 efficiencies approaching 19 percent are demonstrated, while 17 percent is achieved for ITO/InP cells. The superior radiation resistance of the two latter cell configurations over both Si and GaAs cells has been shown. InP cells aboard the LIPS3 satellite show no degradation after more than a year in orbit. Computed array specific powers are used to compare the performance of an InP solar cell array to solar dynamic and nuclear systems.

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

    E-print Network

    Tu, Bor-An Clayton

    2013-01-01

    nanowire (nanopillar) solar cells that use CdS or InP. 3.2most efficient solar cells available for residential use andsolar cells presented in this work reside in this category where they will not only incorporate nanotechnology, but also use

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Characterization of cadmium zinc telluride solar cells

    Microsoft Academic Search

    Gowri Sivaraman

    2003-01-01

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

  12. Assessing potential risk to alligators, Alligator mississippiensis, from nutria control with zinc phosphide rodenticide baits.

    PubMed

    Witmer, Gary W; Eisemann, John D; Primus, Thomas M; O'Hare, Jeanette R; Perry, Kelly R; Elsey, Ruth M; Trosclair, Phillip L

    2010-06-01

    Nutria, Myocastor coypus, populations must be reduced when they cause substantial wetland damage. Control can include the rodenticide zinc phosphide, but the potential impacts to American alligators, Alligator mississippiensis, must be assessed. The mean amount of zinc phosphide per nutria found in nutria carcasses was 50 mg. Risk assessment determined that a conservative estimate for maximum exposure would be 173 mg zinc phosphide for a 28 kg alligator, or 6.2 mg/kg. Probit analysis found an LD(50) for alligators of 28 mg/kg. Our studies suggest that the use of zinc phosphide to manage nutria populations would pose only a small risk to alligators. PMID:20431861

  13. Epitaxial gallium phosphide on silicon (111) from the liquid phase for solar cell applications

    Microsoft Academic Search

    Susan R. Huang

    2010-01-01

    Multijunction structures composed of III-V materials grown on a III-V or Ge substrate are often employed to achieve high solar cell conversion efficiencies. However, it is advantageous to consider alternate substrates that can lower cost, such as the well developed Si, as a platform on which multi-junction solar structures can be grown. Growth of III-Vs on an alternate substrate such

  14. 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.

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

    NASA Astrophysics Data System (ADS)

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

    1981-03-01

    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.

  16. Modelling and design of high efficiency radiation tolerant indium phosphide space solar cells

    NASA Technical Reports Server (NTRS)

    Goradia, Chandra; Geier, James V.; Weinberg, Irving

    1987-01-01

    Using a fairly comprehensive model, a parametric variation study was performed of the InP shallow homojunction solar cell with a view to determining the maximum realistically achievable efficiency and an optimum design that would yield this efficiency. Calculations show that with good-quality epitaxial material, a beginning-of-life efficiency of about 20.3 precent at 1AM0, 25 C may be possible. The design parameters of the near-optimum cell are given. Also presented are the expected effect on the performance parameters of radiation damage by 1-MeV electrons and a possible explanation of the high radiation tolerance of InP solar cells.

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

    NASA Technical Reports Server (NTRS)

    Goradia, Chandra; Thesling, William; Weinberg, Irving

    1991-01-01

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

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

    NASA Technical Reports Server (NTRS)

    Goradia, Chandra; Thesling, William; Weinberg, Irving

    1990-01-01

    Solar cells made from gallium arsenide (Gaas), with a room temperature bandgap of E(sub g) = 1.43 eV have exhibited the best measured open circuit voltage (V sub oc) of 1.05 V at 1 AM0, 25 C. The material InP is in many ways similar to GaAs. A simple calculation comparing InP to GaAs then shows that solar cells made from InP, with E(sub g) = 1.35 at 300 K, should exhibit the best measured V sub oc of approximately 950 mV at 1 AM0, 300 K. However, to date, the best measured V sub oc for InP solar cells made by any fabrication method is 899 mV at AM1.5, 25 C which would translate to 912 mV at 1 AM0, 25 C. The V sub oc of an n(+)pp(+) InP solar cell is governed by several factors. Of these, some factors, such as the thickness and doping of the emitter and base regions, are easily controlled and can be adjusted to desired values dictated by a good performance optimizing model. Such factors were not considered. There are other factors which also govern V sub oc, and their values are not so easily controlled. The primary ones among these are (1) the indirect or Hall-Shockley-Read lifetimes in the various regions of the cell, (2) the low-doping intrinsic carrier concentration n(sub i) of the InP material, (3) the heavy doping factors in the emitter and BSF regions, and (4) the front surface recombination velocity S(sub F). The influence of these latter factors on the V sub oc of the n(+)pp(+) InP solar cell and the results were used to produce a near-optimum design of the n(+)pp(+) InP solar cell.

  19. Modelling and design of high efficiency radiation tolerant indium phosphide space solar cells

    Microsoft Academic Search

    Chandra Goradia; James V. Geier; Irving Weinberg

    1987-01-01

    Using a fairly comprehensive model, a parametric variation study was performed of the InP shallow homojunction solar cell with a view to determining the maximum realistically achievable efficiency and an optimum design that would yield this efficiency. Calculations show that with good-quality epitaxial material, a beginning-of-life efficiency of about 20.3 precent at 1AM0, 25 C may be possible. The design

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

    SciTech Connect

    Yoshimura, Masatoshi, E-mail: yoshimura@rciqe.hokudai.ac.jp; Nakai, Eiji; Fukui, Takashi [Graduate School of Information Science and Technology, and Research Center for Integrated Quantum Electronics (RCIQE), Hokkaido University, Kita 13 Nishi 8, Sapporo 060–8628 (Japan)] [Graduate School of Information Science and Technology, and Research Center for Integrated Quantum Electronics (RCIQE), Hokkaido University, Kita 13 Nishi 8, Sapporo 060–8628 (Japan); Tomioka, Katsuhiro [Graduate School of Information Science and Technology, and Research Center for Integrated Quantum Electronics (RCIQE), Hokkaido University, Kita 13 Nishi 8, Sapporo 060–8628 (Japan) [Graduate School of Information Science and Technology, and Research Center for Integrated Quantum Electronics (RCIQE), Hokkaido University, Kita 13 Nishi 8, Sapporo 060–8628 (Japan); PRESTO, Japan Science and Technology Agency (JST), Honcho Kawaguchi, 332–0012 Saitama (Japan)

    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.

  1. 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.

  2. 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.

  3. Assessing Potential Risk to Alligators, Alligator mississippiensis , from Nutria Control with Zinc Phosphide Rodenticide Baits

    Microsoft Academic Search

    Gary W. Witmer; John D. Eisemann; Thomas M. Primus; Jeanette R. O’Hare; Kelly R. Perry; Ruth M. Elsey; Phillip L. Trosclair

    2010-01-01

    Nutria, Myocastor coypus, populations must be reduced when they cause substantial wetland damage. Control can include the rodenticide zinc phosphide,\\u000a but the potential impacts to American alligators, Alligator mississippiensis, must be assessed. The mean amount of zinc phosphide per nutria found in nutria carcasses was 50 mg. Risk assessment determined\\u000a that a conservative estimate for maximum exposure would be 173 mg zinc

  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/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.

  5. 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.

  6. Amorphous silicon/polycrystalline thin film solar cells

    SciTech Connect

    Ullal, H.S.

    1991-03-13

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

  7. Effect of Zinc Phosphide Rodenticide on Prairie Dog Colony Expansion as Determined From Aerial Photography

    Microsoft Academic Search

    DANIEL W. URESK; GREG L. SCHENBECK

    Aerial photography (1:16,000) was used to evaluate the effectiveness of zinc phosphide in reducing area expansion of black-tailed prairie dog (Cynomys ludovicianus) colonies over a 5-year period in western South Dakota. Untreated prairie dog colonies increased 65 % in area, compared to a 1% increase on treated colonies (P = 0.11). Zinc phosphide, applied at 3-year intervals, was effective in

  8. Identification of phases in thin amorphous films of zinc phosphides

    NASA Astrophysics Data System (ADS)

    Aleinikova, K. B.; Zinchenko, E. N.; Lesovo?, M. V.

    2007-03-01

    Analysis of the experimental atomic radial distribution functions for thin amorphous films of zinc phosphides obtained by explosive laser sputtering has been performed within a fragmentary model. The experiment was carried out with an EMP-100A electron diffractometer in transmitted light at accelerating voltages of 50 and 75 kV. The films obtained by sputtering of ?-ZnP2 single crystals contained nanoparticles of this phase. The films based on Zn3P2 turned out to be two-phase and consisted of dispersed Zn3P2 and ?-ZnP2 nanoparticles. The composition of the film obtained on the basis of ?-ZnP2 corresponded neither to any one of the known phases in the Zn-P system nor to any mixture of these phases. Crystallization of films in a divergent electron beam confirmed the results of the phase analysis performed using the model atomic radial distribution functions.

  9. 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.

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

    SciTech Connect

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

    1992-04-01

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

  11. Identification of phases in thin amorphous films of zinc phosphides

    SciTech Connect

    Aleinikova, K. B.; Zinchenko, E. N., E-mail: zinchenko@phys.vsu.ru; Lesovoi, M. V. [Voronezh State University (Russian Federation)

    2007-03-15

    Analysis of the experimental atomic radial distribution functions for thin amorphous films of zinc phosphides obtained by explosive laser sputtering has been performed within a fragmentary model. The experiment was carried out with an Emp-10a electron diffractometer in transmitted light at accelerating voltages of 50 and 75 kV. The films obtained by sputtering of {beta}-ZnP{sub 2} single crystals contained nanoparticles of this phase. The films based on Zn{sub 3}P{sub 2} turned out to be two-phase and consisted of dispersed Zn{sub 3}P{sub 2} and {beta}-ZnP{sub 2} nanoparticles. The composition of the film obtained on the basis of {alpha}-ZnP{sub 2} corresponded neither to any one of the known phases in the Zn-P system nor to any mixture of these phases. Crystallization of films in a divergent electron beam confirmed the results of the phase analysis performed using the model atomic radial distribution functions.

  12. Predicted performance of near-optimally designed indium phosphide space solar cells at high intensities and temperatures

    NASA Technical Reports Server (NTRS)

    Goradia, Chandra; Thesling, William; Goradia, Manju Ghalla; Weinberg, Irving; Swartz, Clifford K.

    1988-01-01

    The authors calculated the expected performance dependence of near-optimally designed shallow homojunction n+pp+ InP solar cells on incident intensities up to 200 AM0 and temperatures up to 100 deg C (373 K). Both circular and rectangular cells were considered, the former for use in a Cassegrainian concentrator array at 100 AM0, 80-100 deg C and the latter for use in a Slats concentrator array at 20 AM0, 80-100 deg C. With efficiencies near 22 percent at 80 deg C, both the circular and rectangular InP shallow homojunction solar cells compare very favorably to GaAs cells of the same design and may be preferable to the GaAs cells for space applications because of the superior radiation tolerance of the InP cells.

  13. 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.

  14. 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.

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

    PubMed

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

    2015-01-25

    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/cm(2), Voc of 412 mV, FF of 0.56 and an overall conversion efficiency of 0.81 at full sun (1000 W m(-2)). PMID:25128681

  16. Atomic Layer Deposition of zinc oxide for solar cell applications

    NASA Astrophysics Data System (ADS)

    Moret, M.; Abou Chaaya, A.; Bechelany, M.; Miele, P.; Robin, Y.; Briot, O.

    2014-11-01

    Atomic Layer Deposition (ALD) is a vapor phase thin film deposition technique, performed at low substrate temperatures, which enables the deposition of extremely uniform thin films. This technique is scalable up to very large substrates, making it very interesting for industrial applications. On the other hand, ZnO, both undoped and aluminum doped is commonly used as a transparent electrode in solar cells based on Cu(In,Ga)Se2 (CIGS), and is usually deposited by Physical Vapor Deposition techniques. In this paper, we investigate the potential of ALD for the deposition of ZnO windows for solar cell applications. Thin films of a few hundreds of nanometers were grown by ALD, both undoped and doped with aluminum. They were studied by X-ray diffraction, electrical transport measurements, Atomic Force Microscopy and transmittance experiments.

  17. Indium phosphide/cadmium sulfide thin-film solar cells. Final report, May 1979 through July 1980

    SciTech Connect

    Zanio, K.

    1980-09-01

    Thin-film InP/RXCdS/ITO/GLASS devices were prepared by depositing ITO on low-cost glass substrate, depositing CdS on the ITO by thermal evaporation, increasing the CdS lateral grain size by recrystallization, and depositing p-type InP by planar reactive deposition (PRD) on the recrystallized CdS (RXCdS). Yields of the RXCdS/ITO/GLASS substrates were increased to 90% with lateral dimensions of the RXCdS grains as large as 0.3 mm. P-type InP layers were obtained with Be doping. S-doping via vapor transport from the CdS was eliminated by capping the entire RXCdS substrate with InP. For InP deposited on RXCdS at 380/sup 0/C, devices showed blocking action with a barrier height of about 0.5 V but no light response, possibly due to an intermediate approx. 3-..mu..m-thick n-InP layer from diffusion of S from the RXCdS. These results were achieved despite poor InP epitaxy due to an approx. 0.5-..mu..m-thick In-Cd-S transition layer between the InP and the RXCdS. InP films were subsequently deposited on RXCdS at the reduced substrate temperature of 280/sup 0/C to reduce S-diffusion and improve the quality of the epitaxy. Complete InP epitaxy on RXCdS was achieved with the lateral dimensions of the InP (approx. = 40 ..mu..m) replicating that of the RXCdS. Given the increase in the concentration of n-type native defects as substrate temperature is decreased, the present lower limit for obtaining p-type InP by vacuum technologies appears to be about 300/sup 0/C. A 300 to 350/sup 0/C range of substrate temperature appears to befeasible for preparing large-grained p-type InP for both frontwall and backwall cell. However, if the thickness of the n-type layer due to S diffusion cannot be kept to less than a few thousand Angstroms, then development must be restricted to the frontwall cells.

  18. Conjugated phosphonic acid modified zinc oxide electron transport layers for improved performance in organic solar cells.

    PubMed

    Braid, Jennifer L; Koldemir, Unsal; Sellinger, Alan; Collins, Reuben T; Furtak, Thomas E; Olson, Dana C

    2014-11-12

    Phosphonic acid modification of zinc oxide (ZnO) electron transport layers in inverted P3HT:ICBA solar cells was studied to determine the effect of conjugated linkages between the aromatic and phosphonic acid attachment groups. For example, zinc oxide treated with 2,6-difluorophenylvinylphosphonic acid, having a conjugated vinyl group connecting the aromatic moiety to the phosphonic acid group, showed a 0.78 eV decrease in the effective work function versus unmodified ZnO, whereas nonconjugated 2,6-difluorophenylethylphosphonic acid resulted in a 0.57 eV decrease, as measured by Kelvin probe. This resulted in an average power conversion efficiency of 5.89% for conjugated 2,6-difluorophenyvinylphosphonic acid modified solar cells, an improvement over unmodified (5.24%) and nonconjugated phosphonic acid modified devices (5.64%), indicating the importance of the conjugated linkage. PMID:25329245

  19. Aging of flat heterojunction zinc phthalocyanine\\/fullerene C 60 organic solar cells

    Microsoft Academic Search

    R. Lessmann; Z. Hong; S. Scholz; B. Maennig; M. K. Riede; K. Leo

    2010-01-01

    This work addresses the long-term aging of organic solar cells based on a flat zinc phthalocyanine (ZnPc)\\/C60 heterojunction. We investigate both the typical degradation behavior of the short circuit current and of the saturated photocurrent, defined as I(?1V). The latter remains constant after a relatively small initial decay, which is directly related to a substantial reduction of the contribution of

  20. Space solar cell research

    NASA Technical Reports Server (NTRS)

    Flood, Dennis J.

    1989-01-01

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

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

    E-print Network

    .1063/1.4789855] The toxicity of Cd and the scarcity of Te, In, and Ga used in CdTe and Cu(In,Ga)S2 (CIGS) thin-film solar cellsEnhancing the efficiency of SnS solar cells via band-offset engineering with a zinc oxysulfideS is a promising earth-abundant material for photovoltaic applications. Heterojuction solar cells were made

  2. 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

    2015-06-01

    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

  3. The complex interface chemistry of thin-film silicon/zinc oxide solar cell structures.

    PubMed

    Gerlach, D; Wimmer, M; Wilks, R G; Félix, R; Kronast, F; Ruske, F; Bär, M

    2014-12-21

    The interface between solid-phase crystallized phosphorous-doped polycrystalline silicon (poly-Si(n(+))) and aluminum-doped zinc oxide (ZnO:Al) was investigated using spatially resolved photoelectron emission microscopy. We find the accumulation of aluminum in the proximity of the interface. Based on a detailed photoemission line analysis, we also suggest the formation of an interface species. Silicon suboxide and/or dehydrated hemimorphite have been identified as likely candidates. For each scenario a detailed chemical reaction pathway is suggested. The chemical instability of the poly-Si(n(+))/ZnO:Al interface is explained by the fact that SiO2 is more stable than ZnO and/or that H2 is released from the initially deposited a-Si:H during the crystallization process. As a result, Zn (a deep acceptor in silicon) is "liberated" close to the silicon/zinc oxide interface presenting the inherent risk of forming deep defects in the silicon absorber. These could act as recombination centers and thus limit the performance of silicon/zinc oxide based solar cells. Based on this insight some recommendations with respect to solar cell design, material selection, and process parameters are given for further knowledge-based thin-film silicon device optimization. PMID:25363298

  4. Enhanced stability of zinc oxide-based hybrid polymer solar cells by manipulating ultraviolet light distribution in the active layer

    Microsoft Academic Search

    Shuyan Shao; Jian Liu; Baohua Zhang; Zhiyuan Xie; Lixiang Wang

    2011-01-01

    Polymer solar cells based on blends of conjugated polymer and zinc oxide (ZnO) nanoparticles degrade very fast under simulated solar light illumination due to the considerably increased photoconductivity of ZnO upon ultraviolet light exposure. It is reported that the stability of hybrid polymer solar cells with ZnO as electron acceptors is improved by using an optical layer to decrease ultraviolet

  5. 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.

  6. Development of Novel Aluminum-Doped Zinc Oxide Film and Its Application to Solar Cells

    NASA Astrophysics Data System (ADS)

    Kuramochi, Hideto; Akiike, Ryo; Iigusa, Hitoshi; Tamano, Kimiaki; Utsumi, Kentaro; Shibutami, Tetsuo; Sichanugrist, Porponth; Konagai, Makoto

    2012-10-01

    We have developed novel aluminum-doped zinc oxide films (AZO-X and AZO-HX films) with a high haze value using wet-chemical etching for various times after dc magnetron sputtering, and have investigated their electrical and optical properties, durability under high-humidity condition, and surface morphology. The AZO-X and AZO-HX films showed good balance between transmittance in the near-infrared area and durability under 85 °C-85%RH condition. These novel films also had a higher haze value after wet chemical etching than normal AZO films. The crater size and haze value of the AZO-HX film increased with increasing etching time in comparison with those of the AZO-X film. The haze value of the AZO-HX film was higher than that of the AZO-X film; their values are 90% at 550 nm and 60% at 800 nm. Furthermore, the AZO-HX film was applied in amorphous silicon (a-Si) single-type solar cells as the front electrode. The short-circuit current of the solar cell using the AZO-HX film was higher than that of the solar cell using the AZO-X film. As an optimization-based result, an efficiency as high as 10.2% was obtained, showing that the new AZO-HX film is a promising material for the front electrode of a-Si solar cells.

  7. 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.

  8. Chemical bath deposited zinc sulfide buffer layers for copper indium gallium sulfur-selenide solar cells and device analysis

    Microsoft Academic Search

    Sambhu N. Kundu; Larry C. Olsen

    2005-01-01

    Cadmium-free copper indium gallium sulfur-selenide (CIGSS) thin film solar cells have been fabricated using chemical bath deposited (CBD) zinc sulfide (ZnS) buffer layers. Shell Solar Industries provided high quality CIGSS absorber layers. The use of CBD-ZnS, which is a higher band gap material than CdS, improved the quantum efficiency of fabricated cells at lower wavelengths, leading to an increase in

  9. 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.

  10. Evaluation of strychnine and zinc phosphide baits to control northern pocket gophers ( Thomomys talpoides) in alfalfa fields in Alberta, Canada

    Microsoft Academic Search

    Gilbert Proulx

    1998-01-01

    This study compared the effectiveness of Sanex 0.40% strychnine-treated oats, Fairview 0.37% strychnine-treated grains, and United Agri Products 2% zinc phosphide-treated oats to control northern pocket gopher (Thomomys talpoides) populations in alfalfa fields in Alberta, Canada. The poison baits were tested during three phenological periods corresponding to the reproduction, summer juvenile dispersal, and early fall mound building activities. Overall, less

  11. 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.

  12. Electronic and Optical Properties of Thin Films of Mercury Zinc Telluride and Cadmium Sulphide for Solar Cell Devices

    NASA Astrophysics Data System (ADS)

    Arshed, Shaheen

    1990-08-01

    Available from UMI in association with The British Library. Thin films of cadmium sulphide (CdS), zinc telluride (ZnTe), mercury telluride (HgTe) and a novel semiconductor "mercury zinc telluride" (rm Hg_{1 -x}Zn_{x}Te) were deposited onto soda lime glass slides and Corning 7059 glass substrates using the thermal evaporation technique. The electronic, optical and structural properties of these films were studied to assess their viability for use in photovoltaic devices, in particular, their potential to make rm CdS/Hg_{1-x}Zn_{x}Te heterojunctions for use as solar cells. (Abstract shortened by UMI.).

  13. 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...

  14. 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.

  15. Gallium phosphide energy converters

    Microsoft Academic Search

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

    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

  16. Photoelectrochemical cell having photoanode with thin boron phosphide coating as a corrosion resistant layer

    SciTech Connect

    Baughman, Richard J. (Albuquerque, NM); Ginley, David S. (Albuquerque, NM)

    1984-01-01

    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 anitcorrosive, and providing it with unexpectedly improved photoresponsive properties.

  17. Photoelectrochemical cell having photoanode with thin boron phosphide coating as a corrosion resistant layer

    SciTech Connect

    Baughman, R.S.; Ginley, D.S.

    1984-03-20

    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.

  18. Improved Inverted Organic Solar Cells With a Sol–Gel Derived Indium-Doped Zinc Oxide Buffer Layer

    Microsoft Academic Search

    Aung Ko Ko Kyaw; Xiaowei Sun; De Wei Zhao; Swee Tiam Tan; Yoga Divayana; Hilmi Volkan Demir

    2010-01-01

    We studied sol-gel derived indium-doped zinc oxide (IZO) with various indium contents as a functional buffer layer in inverted polymer:fullerene bulk-heterojunction solar cell. The short-circuit current density was observed to increase by doping indium in pure ZnO buffer layer. The maximum current density was obtained with a 1 at.% indium doping. Although the open-circuit voltage and fill factor reduced slightly,

  19. 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 ...

  20. 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.

  1. 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. [University of South Florida, Tampa, FL (United States)

    1992-04-01

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

  2. Novel nanostructure zinc zirconate, zinc oxide or zirconium oxide pastes coated on fluorine doped tin oxide thin film as photoelectrochemical working electrodes for dye-sensitized solar cell.

    PubMed

    Hossein Habibi, Mohammad; Askari, Elham; Habibi, Mehdi; Zendehdel, Mahmoud

    2013-03-01

    Zinc zirconate (ZnZrO(3)) (ZZ), zinc oxide (ZnO) (ZO) and zirconium oxide (ZrO(2)) (ZRO) nano-particles were synthesized by simple sol-gel method. ZZ, ZO and ZRO nano-particles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and UV-Vis diffuse reflectance spectrum (DRS). Nanoporous ZZ, ZO and ZRO thin films were prepared doctor blade technique on the fluorine-doped tin oxide (FTO) and used as working electrodes in dye sensitized solar cells (DSSC). Their photovoltaic behavior were compared with standard using D35 dye and an electrolyte containing [Co(bpy)(3)](PF(6))(2), [Co(pby)(3)](PF(6))(3), LiClO(4), and 4-tert-butylpyridine (TBP). The properties of DSSC have been studied by measuring their short-circuit photocurrent density (Jsc), open-circuit voltage (VOC) and fill factor (ff). The application of ZnZrO(3) as working electrode produces a significant improvement in the fill factor (ff) of the dye-sensitized solar cells (ff=56%) compared to ZnO working electrode (ff=40%) under the same condition. PMID:23266694

  3. Effects of Transition Metal Dichalcogenide Molybdenum Disulfide Layer Formation in Copper-Zinc-Tin-Sulfur Solar Cells from Numerical Analysis

    NASA Astrophysics Data System (ADS)

    Chelvanathan, Puvaneswaran; Istiaque Hossain, Mohammad; Husna, Jamilah; Alghoul, Mohammad; Sopian, Kamaruzzaman; Amin, Nowshad

    2012-10-01

    This study demonstrates the effects of transition metal dichalcogenide, MoS2 layer formation in between the copper-zinc-tin-sulphide (CZTS) absorber layer and Mo back contact from theoretical study and numerical modeling. The objective of this study is to elucidate the effects of n or p type MoS2 on the overall CZTS solar cell performance. Energy band line-up of Mo/MoS2/CZTS interface is analyzed to elucidate the interface properties. It is found out that p-MoS2 layer in CZTS solar cell induces the same adventitious effect as p-MoSe2 in CIGS solar cell. However, n-MoS2 layer has detrimental effect on the CZTS solar cell by creating an additional back contact diode with p-CZTS layer and an ohmic contact with Mo layer. Thickness, bandgap energy and carrier concentration of n-MoS2 all have been varied in the numerical simulation to observe its effects on the cell performance parameters. The results from numerical simulation show that MoS2 layer as thin as 50 nm is sufficient enough to induce adverse effect on the solar cell performance. This could be caused by the increase in series resistance of the solar cell as n-type MoS2 would inhibit hole current into Mo back contact due to the hole barrier between n-type MoS2 and Mo back contact. The increase in MoS2 bandgap and carrier concentration also results in detrimental effect to the performance of the cell mainly due to the possibility of electrons to drift towards the back contact and recombine.

  4. Study on the bulk junction type organic solar cells with double zinc oxide layer

    Microsoft Academic Search

    Xiaohui Ju; Wei Feng; Varutt Kittichungchit; Tetsuro Hori; Hiroki Moritou; Akihiko Fujii; Masanori Ozaki

    2009-01-01

    The optical and photovoltaic properties of a photovoltaic cell with a structure of indium–tin oxide (ITO)\\/double ZnO\\/poly(3-hexylthiophene) (PAT6):PCBM\\/Ag have been investigated. The double layer ZnO was a composite of a sputtered ZnO layer and oriented zinc oxide nanopillars layer which was fabricated by a new method at low temperature (343 K). It is concluded that the double layer ZnO plays an

  5. The control of radiation resistance in space solar cells

    Microsoft Academic Search

    ARTHUR F. W. WILLOUGHBY

    1994-01-01

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

  6. 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

    2015-06-18

    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

  7. Synthesis of zinc phthalocyanine with large steric hindrance and its photovoltaic performance for dye-sensitized solar cells.

    PubMed

    Lin, Li; Peng, Bosi; Shi, Wenye; Guo, Yingying; Li, Renjie

    2015-03-28

    A zinc phthalocyanine (ZnPc) derivative (Zn-tri-PcNc-8) containing tri-benzonaphtho-condensed porphyrazine with one carboxylic and six diphenylphenoxy peripheral substitutions was designed and synthesized as a sensitizer for dye-sensitized solar cells (DSSCs). For the purpose of extending the absorption spectra while minimizing the formation of ZnPc molecular aggregates, bulky 2,6-diphenylphenoxy groups were used as electron donor moieties, and the carboxylic group as an anchoring group to graft the sensitizer onto the semiconductor. It was found that a TiO2-based solar cell sensitized by Zn-tri-PcNc-8 shows a maximum incident photon-to-current conversion efficiency in the red/near-IR light range (650-750 nm), and a solar cell sensitized at near room temperature (30 °C) for 48 h exhibits the best efficiency (3.01%). The efficiency was much higher than that (1.96%) for a solar cell sensitized by its analogue (Zn-tri-PcNc-2) having one carboxyl and three tert-butyl groups without chenodeoxycholic acid (CDCA), indicating that the introduction of six bulky diphenylphenoxy substitutions with large steric hindrance in the ZnPc macrocycle can effectively suppress the molecular aggregates, thus resulting in an improved conversion efficiency. The present results shed light on an effective solution to adjust the ZnPc property via chemical modification such as changing the "push-pull" effect and adding large steric hindrance substituents to further improve the efficiency of the phthalocyanine-sensitized solar cell. PMID:25716344

  8. Zinc Oxide/Silicon Heterojunction Solar Cell Simulation and Experimental Evaluation

    NASA Astrophysics Data System (ADS)

    Tong, Chong

    2011-12-01

    A new type of solar cell---ZnO/Si hetero-junction solar cells were explored for their potentially low cost application. The main focus of this work is to study the properties and characteristics of n-ZnO/p-Si heterojunction solar cells. In order to find the optimal design structure of ZnO/p-Si solar cells, numerical modeling using AMPS-1D was performed on various thicknesses, doping densities and junction structures. All the input parameters were chosen based on experimental values, literature values, theory and reasonable estimates. In addition, graded doping layer and back surface field (BSF) layer were also introduced to achieve improvement on the performance. Due to the nature of heterojunctions, defects are very easily formed at the junction interface. The ZnO/p-Si solar cell simulations with a Si interface layer of 50nm, defect density of 1 x 1014 cm-3 , near mid-gap defect location, and capture cross section of 1 x 10 -10 -- 1 x 10-8 cm2 were also performed. Result showed a "bending" I-V curve and low fill factor as we expected. The influences of defect layer thickness and defect location were discussed. Results also showed that the main reason for the bad performance is the defects in the Si surface rather than the ZnO surface. Those defects could be affected by a combination of interface layer thickness, defect density, defect capture cross section and defect location. After the simulation work, ZnO/p-Si heterojunction solar cell devices have been fabricated. Specific studies like SEM, XRD, I-V measurement were performed. The "bending" I-V shape and low fill factor were predicted by our AMPS-1D simulation. The transport mechanism was discussed by using space charge limited current (SCLC) theory. Even the best cell (300nm AZO/ 50nm ZnO/ 550um p-Si) only showed a short circuit current of 4.6 mA/cm2, an open circuit voltage of 0.15V and an efficiency less than 1%. Because ZnO/n-Si solar cells give normally better efficiency of ˜8% if compared with ZnO/p-Si solar cells, a comparison of these two types of solar cells was performed in the last chapter of this thesis. For ZnO/n-Si solar cells, dark current follows the traditional exponential equation, indicating a traditional p-n junction transport mechanism. However, ZnO/p-Si solar cells can only be explained by the SCLC mechanism. Then, a possible method to improve ZnO/p-Si solar cells performance was proposed. By adding a thin layer (5nm or 1um) of highly doped n-Si between ZnO and p-Si layer can greatly improve the performance. This structure was also simulated by using AMPS-1D, increasing the efficiency from 0.4% to 11.7%.

  9. Dye sensitized solar cells using well-aligned zinc oxide nanotip arrays

    NASA Astrophysics Data System (ADS)

    Du Pasquier, Aurelien; Chen, Hanhong; Lu, Yicheng

    2006-12-01

    Well-aligned zinc oxide (ZnO) nanotip arrays were grown on fluorinated tin oxide coated glass using metal organic chemical vapor deposition. Dye (N719) sensitized photoelectrochemical cells comprising of ZnO nanotip arrays were fabricated and characterized. It is found that the power conversion efficiency of the cells increases with the length of the ZnO nanotips. The cells with 3.2?m ZnO nanotip array exhibited an incident photon-to-current conversion efficiency of 21.1% (at 550nm) and a power conversion efficiency of 0.55% under 1 sun irradiance. Light harvesting in ZnO nanotips also contributes to the photocurrent in the UV range.

  10. Development of Novel Al-Doped Zinc Oxide Films Fabricated on Etched Glass and Their Application to Solar Cells

    NASA Astrophysics Data System (ADS)

    Hongsingthong, Aswin; Aino, Akehiro; Sichanugrist, Porponth; Konagai, Makoto; Kuramochi, Hideto; Akiike, Ryo; Iigusa, Hitoshi; Utsumi, Kentaro; Shibutami, Tetsuo

    2012-10-01

    We have successfully developed novel aluminum-doped zinc oxide (AZO-X) films with a high haze ratio by the combined use of an etched glass substrate and wet-etched AZO-X films. The effects of the use of an etched glass substrate and wet-chemical etching on the properties of AZO-X films were investigated. The texture size and rms roughness of these films largely increased with glass surface roughening. Post-treatment using wet chemical etching slightly increased the texture size and rms roughness. The etched glass approach has been found to be a promising method for achieving an AZO-coated glass substrate with a high haze ratio. Using high-haze ratio AZO-X films as the front transparent conductive oxide (TCO) layers in solar cells, we improved the quantum efficiency (QE) of these solar cells particularly in the long-wavelength region. Thus, the AZO-X films deposited on etched glass have a high potential for use as front TCO layers in silicon-based thin-film solar cells.

  11. Fabrication and optimization of Al-doped zinc oxide layer for application in radial p-n junction silicon solar cells

    Microsoft Academic Search

    Seong-Ho Baek; Jae Hyun Kim; Jang-Kyoo Shin

    2010-01-01

    The influence of thickness of optimized Al-doped zinc oxide (AZO) front contact layer on an efficiency of a radial p-n junction silicon (Si) solar cell has been studied. Vertically aligned Si wire arrays for the radial p-n junction solar device were fabricated by metal catalytic etching and p-n junction was prepared by spin-on-dopant (SOD) diffusion method. AZO thin films as

  12. 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

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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

    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.

  14. Zinc oxide nanostructures for applications as ethanol sensors and dye-sensitized solar cells

    Microsoft Academic Search

    Supab Choopun; Auttasit Tubtimtae; Theerapong Santhaveesuk; Sanpet Nilphai; Ekasiddh Wongrat; Niyom Hongsith

    2009-01-01

    ZnO nanostructures were prepared by thermal oxidation technique for applying as ethanol sensors and dye-sensitized solar cells. To improve sensitivity of the sensor based on ZnO nanostructures, gold doping was performed in ZnO nanostructures. Gold-doped with 0%, 5%, and 10% by weight were investigated. The improvement of sensor sensitivity toward ethanol due to gold doping was observed at entire operating

  15. Urchin-inspired zinc oxide as building blocks for nanostructured solar cells

    E-print Network

    Elias, Jamil; Utke, Ivo; Erni, Rolf; Hosseini, Davood; Michler, Johann; Philippe, Laetitia

    2012-01-01

    High surface area nanowire based architectures have been identified as important components for future optoelectronic nanodevices, solar cells, wettability coatings, gas sensors, and biofuel cells. Here we report on a novel urchin-inspired nanowire architecture: its interwoven three-dimensional, high-surface-area nanowire arrangement can be precisely controlled by using a low-cost and scalable synthesis based on a combination of nanosphere lithography, low-temperature atomic layer deposition, and electrodeposition. The performance of single-layer arrays of urchin-inspired ZnO nanowire building blocks competes to that of planar nanowire carpets. We illustrate this capability by fabricating fully-inorganic extremely thin absorber solar cells using CdSe as absorber and CuSCN as hole-collector material. The light diffusion of the urchin-inspired nanowire arrays was varied from 15% to 35%. Homogenous absorption in the wavelength range of 400-800 nm of up to 90% was obtained. Solar conversion efficiencies of ~ 1.33...

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

    SciTech Connect

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

    1992-10-01

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

  17. 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.

  18. 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.

  19. Microwave assisted synthesis of zinc stannate nanocubes for dye sensitized solar cell application

    NASA Astrophysics Data System (ADS)

    Jayabal, P.; Sasirekha, V.; Mayandi, J.; Ramakrishnan, V.

    2014-11-01

    The ternary complex oxide Zn2SnO4 (ZS) has become more essential because of its photonic energy conversion, tremendous stability and higher electron mobility compared to the binary counterparts. The ZS nanocubes were prepared by simple microwave assisted route. The cubic spinel structured ZS was confirmed by X-ray diffraction (XRD) and micro-Raman techniques. Scanning electron micrograph revealed the formation of nanocubes with size of ?90 nm. The Dye Sensitized Solar Cells (DSSCs) were fabricated using the synthesized ZS as photoanode and low cost organic dyes such as Rose Bengal (RB), Eosin Yellow (EY) and Fluorescein sodium salt (FY) as sensitizers to study their light conversion efficiencies. The DSSCs exhibited power conversion efficiency (PCE) of 0.64%, 0.05% and 0.02% for RB, EY and FY sensitized films, respectively.

  20. Efficient inverted polymer solar cells using low-temperature zinc oxide interlayer processed from aqueous solution

    NASA Astrophysics Data System (ADS)

    Chen, Dazheng; Zhang, Chunfu; Heng, Ting; Wei, Wei; Wang, Zhizhe; Han, Genquan; Feng, Qian; Hao, Yue; Zhang, Jincheng

    2015-04-01

    In this work, an aqueous solution method that entails processing at low temperatures is utilized to deposit a ZnO interlayer in poly(3-hexylthiophene-2,5-diyl):[6,6]-phenyl C61 butyric acid methyl ester-based inverted polymer solar cells (PSCs). The effect of ZnO annealing temperature from 50 to 150 °C on PSC performance is systemically studied and it is found that the transition point is approximately 80 °C. When the ZnO annealing temperature is higher than 80 °C, PSCs show similar current density–voltage (J–V) characteristics and achieve a power conversion efficiency higher than 3.5%. Transmittance spectrum, PL spectrum, and surface morphology studies show that an annealing temperature above 80 °C is sufficient for ZnO to achieve a relatively good quality, and that a higher temperature only slightly improves ZnO quality, which is confirmed from statistical results. Furthermore, flexible PSCs based on PET substrates show a comparable power conversion efficiency and good flexibility.

  1. 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

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

    PubMed

    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

  3. Suppression of zinc dendrites in zinc electrode power cells

    NASA Technical Reports Server (NTRS)

    Damjanovic, A.; Diggle, J. W.

    1970-01-01

    Addition of various tetraalkyl quarternary ammonium salts, to alkaline zincate electrolyte of cell, prevents formation of zinc dendrites during charging of zinc electrode. Electrode capacity is not impaired and elimination of dendrites prolongs cell life.

  4. Aggregation of zinc oxide nanoparticles: From non-aqueous dispersions to composites used as photoactive layers in hybrid solar cells

    Microsoft Academic Search

    R. Rhodes; M. Horie; H. Chen; Z. Wang; M. L. Turner; B. R. Saunders

    2010-01-01

    Hybrid solar cells are third-generation solar cells that are colloidal in nature. The composites used as photoactive layers within hybrid solar cells comprise conjugated polymers and inorganic semiconductor nanoparticles (e.g., nanocrystals and nanorods). The composites are usually prepared by spin casting non-aqueous dispersions consisting of polymer, nanoparticles and a co-solvent blend. The factors governing colloidal stability of the dispersions used

  5. Solution Processing of Cadmium Sulfide Buffer Layer and Aluminum-Doped Zinc Oxide Window Layer for Thin Films Solar Cells

    NASA Astrophysics Data System (ADS)

    Alam, Mahboob; Islam, Mohammad; Achour, Amine; Hayat, Ansar; Ahsan, Bilal; Rasheed, Haroon; Salam, Shahzad; Mujahid, Mohammad

    2014-07-01

    Cadmium sulfide (CdS) and aluminum-doped zinc oxide (Al:ZnO) thin films are used as buffer layer and front window layer, respectively, in thin film solar cells. CdS and Al:ZnO thin films were produced using chemical bath deposition (CBD) and sol-gel technique, respectively. For CBD CdS, the effect of bath composition and temperature, dipping time and annealing temperature on film properties was investigated. The CdS films are found to be polycrystalline with metastable cubic crystal structure, dense, crack-free surface morphology and the crystallite size of either few nanometers or 12-17 nm depending on bath composition. In case of CdS films produced with 1:2 ratio of Cd and S precursors, spectrophotometer studies indicate quantum confinement effect, owing to extremely small crystallite size, with an increase in Eg value from 2.42 eV (for bulk CdS) to 3.76 eV along with a shift in the absorption edge toward 330 nm wavelength. The optimum annealing temperature is 400°C beyond which film properties deteriorate through S evaporation and CdO formation. On the other hand, Al:ZnO films prepared via spin coating of precursor sols containing 0.90-1.10 at.% Al show that, with an increase in Al concentration, the average grain size increases from 28 nm to 131 nm with an associated decrease in root-mean-square roughness. The minimum value of electrical resistivity, measured for the films prepared using 0.95 at.% Al in the precursor sol, is 2.7 × 10-4 ? ? cm. The electrical resistivity value rises upon further increase in Al doping level due to introduction of lattice defects and Al segregation to the grain boundary area, thus limiting electron transport through it.

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

    SciTech Connect

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

    1990-10-01

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

  7. 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.

  8. Gallium phosphide energy converters

    NASA Astrophysics Data System (ADS)

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

    1995-10-01

    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.

  9. Gallium phosphide energy converters

    SciTech Connect

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

    1995-10-01

    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 {minus}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.

  10. Nanowire-based All Oxide Solar Cells

    Microsoft Academic Search

    Benjamin D. Yuhas; Peidong; Peidong Yang

    2008-01-01

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

  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. Automatically activated, 300 ampere-hour silver-zinc cell

    NASA Technical Reports Server (NTRS)

    Hennigan, T. J.

    1972-01-01

    A prototype silver zinc cell is reported for which the electrolyte is being stored in a separate tank; the cell is being activated when additional power is required by collapsing the neoprene bellows container and thus forcing the electrolyte into cell through a plastic connection. A solar array is proposed as main power source for the flow actuator.

  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. 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.

  17. Morphological and Electrical Properties of Self-Textured Aluminum-Doped Zinc Oxide Films Prepared by Direct Current Magnetron Sputtering for Application to Amorphous Silicon Solar Cells

    NASA Astrophysics Data System (ADS)

    Kim, Young Baek; Choi, Bum Ho; Lee, Jong Ho; Hyeok Kim, Jin

    2011-06-01

    Self-textured Al-doped zinc oxide (AZO) transparent conducting oxide (TCO) layers were grown by DC magnetron sputtering, and their morphological and electrical properties were investigated. The self-textured AZO layers were fabricated by controlling the deposition conditions, without employing wet or dry etching for surface texturing. The polycrystalline AZO layers with a high surface roughness (42 nm) were grown on a glass substrate at various DC plasma power. The lowest sheet resistance was 3.7×10-4 ? cm and the highest carrier mobility obtained was 30 cm2 V-1 s-1, which are comparable to those of chemically textured AZO layers. The electrical and optical characteristics of the self-textured AZO films are comparable to those of wet-etched AZO films that were etched using the conventional HCl solution. Our study suggests a possible way to inexpensively fabricate amorphous silicon thin-film solar cells.

  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, E-mail: cfzhang@xidian.edu.cn; Wang, Zhizhe; Zhang, Jincheng; Tang, Shi; Wei, Wei; Sun, Li; Hao, Yue, E-mail: yhao@xidian.edu.cn [State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology, School of Microelectronics, Xidian University, No. 2 South Taibai Road, Xi'an 710071 (China)

    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. Occupational phosphine gas poisoning at veterinary hospitals from dogs that ingested zinc phosphide--Michigan, Iowa, and Washington, 2006-2011.

    PubMed

    2012-04-27

    Zinc phosphide (Zn3P2) is a readily available rodenticide that, on contact with stomach acid and water, produces phosphine (PH3), a highly toxic gas. Household pets that ingest Zn3P2 often will regurgitate, releasing PH3 into the air. Veterinary hospital staff members treating such animals can be poisoned from PH3 exposure. During 2006-2011, CDC's National Institute for Occupational Safety and Health (NIOSH) received reports of PH3 poisonings at four different veterinary hospitals: two in Michigan, one in Iowa, and one in Washington. Each of the four veterinary hospitals had treated a dog that ingested Zn3P2. Among hospital workers, eight poisoning victims were identified, all of whom experienced transient symptoms related to PH3 inhalation. All four dogs recovered fully. Exposure of veterinary staff members to PH3 can be minimized by following phosphine product precautions developed by the American Veterinary Medical Association (AVMA). Exposure of pets, pet owners, and veterinary staff members to PH3 can be minimized by proper storage, handling, and use of Zn3P2 and by using alternative methods for gopher and mole control, such as snap traps. PMID:22534761

  20. Novel zinc porphyrin sensitizers for dye-sensitized solar cells: Synthesis and spectral, electrochemical, and photovoltaic properties

    NASA Astrophysics Data System (ADS)

    Tan, Qinglong; Zhang, Xuejun; Mao, Lijun; Xin, Guanqiong; Zhang, Shuanfen

    2013-03-01

    Two donor-?-spacer-acceptor porphyrin dyes were synthesized for use in dye-sensitized solar cells. The dyes comprised the same donor (porphyrin derivative) consisting of 3,4,5-trimethoxybenzaldehyde and acceptor/anchoring group (carboxyl group) but varying ?-spacer consisting of a Schiff base structure. Each of the dyes displayed different adsorption behavior and coverage on the TiO2 surface. The porphyrin dyes PZnsbnd BIAsbnd COOH studied in this work exhibit red-shifted and broadened electronic spectra respect to the reference PZnsbnd COOH as expected. By the introduction of Schiff base unit at the meso positions, the energy level of Eox (excited-state oxidation potentials) is significantly shifted to the positive compared with the reference PZnsbnd COOH, indicating a decreased HOMO-LUMO gap. The highest power conversion efficiency of the two dyes based on DSSCs reached 1.75% under AM 1.5 G irradiation.

  1. solar cells

    Microsoft Academic Search

    Ben Minnaert; Marc Burgelman

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

  2. Synthesis and characterisation of Copper Zinc Tin Sulphide (CZTS) compound for absorber material in solar-cells

    Microsoft Academic Search

    Vipul Kheraj; K. K. Patel; S. J. Patel

    2013-01-01

    The development of thin-film semiconductor compounds, such as Copper Indium Gallium Selenide (CIGS), has caused remarkable progress in the field of thin-film photovoltaics. However, the scarcity and the increasing prices of indium impose the hunt for alternative materials. The Copper Zinc Tin Sulphide (CZTS) is one of the promising emerging materials with Kesterite-type crystal structure and favourable material properties like

  3. The effect of post-annealing treatment on the characteristics of a dye-sensitized solar cell with an indium zinc tin oxide electrode

    NASA Astrophysics Data System (ADS)

    Ma, Hong Chan; Damisih; Putri, Maryane; Cheon, Jong Hoon; Kim, Jae Hong; Lee, Hee Young

    2012-12-01

    Indium-saving transparent conductive oxide (TCO) thin films, i.e., zinc and tin co-doped indium oxide (IZTO) films, were investigated for dye-sensitized solar cell (DSSC) applications. The films were prepared by the radio-frequency (RF) magnetron sputtering method utilizing a ceramic target with a nominal composition equal to In0.6Zn0.2Sn0.2O1.5. The substrate temperature was changed from room temperature to 400 °C while the RF power and the argon gas pressure during deposition were kept constant. The photovoltaic conversion efficiencies of the DSSC samples made with IZTO electrodes were compared with the samples made with FTO electrodes. Values of approximately 6.81% and 4.74% were obtained for the DSSC samples with FTO and IZTO electrodes, respectively, when the firing process was carried out in air atmosphere during DSSC fabrication. However, with the addition of post-annealing in argon or a forming gas, efficiency values increased to 6.06% or 5.54%, respectively, for the DSSC sample with an IZTO electrode.

  4. Amorphous silicon solar cells

    Microsoft Academic Search

    K. Takahashi; M. Konagai

    1986-01-01

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

  5. Electrodeposition of zinc oxide/tetrasulfonated copper phthalocyanine hybrid thin film for dye-sensitized solar cell application

    NASA Astrophysics Data System (ADS)

    Luo, Xinze; Xu, Lin; Xu, Bingbing; Li, Fengyan

    2011-05-01

    Hybrid film of zinc oxide (ZnO) and tetrasulfonated copper phthalocyanine (TSPcCu) was grown on an indium tin oxide (ITO) glass by one-step cathodic electrodeposition from aqueous mixtures of Zn(NO 3) 2, TSPcCu and KCl. The addition of TSPcCu strongly influences the morphology and crystallographic orientation of the ZnO. The nanosheets stack of ZnO leads to a porous surface structure which is advantageous to further adsorb organic dyes. The photovoltaic properties were investigated by assembling the DSSC device based on both the only ZnO film and the ZnO/TSPcCu hybrid films. Photoelectrochemical analysis revealed that the optimized DSSC device with TSPcCu represented a more than three-fold improvement in power conversion efficiency than the device without TSPcCu. The DSSC based on ZnO/TSPcCu hybrid films demonstrates an open circuit voltage of 0.308 V, a short circuit current of 90 ?A cm -2, a fill factor of 0.26, and a power conversion efficiency of 0.14%.

  6. 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.

  7. 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...

  8. Array of solar cells

    Microsoft Academic Search

    1981-01-01

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

  9. Zinc

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zinc was recognized as an essential trace metal for humans during the studies of Iranian adolescent dwarfs in the early 1960s. Zinc metal existing as Zn2+ is a strong electron acceptor in biological systems without risks of oxidant damage to cells. Zn2+ functions in the structure of proteins and is ...

  10. Solar cell shingle

    Microsoft Academic Search

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

    1977-01-01

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

  11. Indium phosphide, indium-gallium-arsenide and indium-gallium-antimonide based high efficiency multijunction photovoltaics for solar energy harvesting

    Microsoft Academic Search

    Indranil Bhattacharya; Simon Y. Foo

    2009-01-01

    Multijunction solar cells direct sunlight towards matched spectral sensitivity by splitting the spectrum into smaller slices. The main challenge in the photovoltaic industry is to make the modules more cost effective. The high efficiency multijunction photovoltaics have played a very significant role in reducing the cost through concentrator photovoltaic systems being implemented around the world. For example National Renewable Energy

  12. Polymer solar cells

    Microsoft Academic Search

    Gang Li; Rui Zhu; Yang Yang

    2012-01-01

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

  13. Amorphous silicon solar cells

    SciTech Connect

    Takahashi, K.; Konagai, M.

    1986-01-01

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

  14. Amorphous silicon solar cells

    NASA Astrophysics Data System (ADS)

    Takahashi, K.; Konagai, M.

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

  15. Space flight experiment: Advanced solar cells and protective materials on the ISS exterior

    Microsoft Academic Search

    Theodore D. Sahlstrom; Paul E. Hausgen; David M. Wilt; Alexander D. Howard; Michael D. Anderson Jr; Neil A. Snyder

    2010-01-01

    A space flight opportunity was seized to fly emerging solar cell, coating, and coverglass technologies in a Low Earth Orbit (LEO) environment while attached to the exterior of the International Space Station (ISS). Included in the flight manifest were nano-crystalline optimized amorphous silicon (a-Si) thin-film, Indium Phosphide (InP), and Inverted Metamorphic (IMM) Photovoltaic (PV) technologies. An array of experimental coatings

  16. Solar cell shingle

    Microsoft Academic Search

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

    1976-01-01

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

  17. Solar-cell project

    Microsoft Academic Search

    B. Mortensen; J. Jensen

    1980-01-01

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

  18. 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…

  19. 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

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

    Microsoft Academic Search

    J. F. Cooper; R. Krueger

    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

  1. 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

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

    NASA Astrophysics Data System (ADS)

    Gerlach, D.; Wilks, R. G.; Wippler, D.; Wimmer, M.; Lozac'h, M.; Félix, R.; Mück, A.; Meier, M.; Ueda, S.; Yoshikawa, H.; Gorgoi, M.; Lips, K.; Rech, B.; Sumiya, M.; Hüpkes, J.; Kobayashi, K.; Bär, M.

    2013-07-01

    The electronic structure of the interface between the boron-doped oxygenated amorphous silicon "window layer" (a-SiOx: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 (?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 ?c-Si:H(B)/ZnO:Al interface compared to that at the a-SiOx:H(B)/ZnO:Al interface is found and linked to the higher device performances in cells where a ?c-Si:H(B) buffer between the a-Si:H p-i-n absorber stack and the ZnO:Al contact is employed.

  3. Response of cultured tomato cells subjected to excess zinc: role of cell wall in zinc compartmentation

    Microsoft Academic Search

    Aurélie Muschitz; Céline Faugeron; Henri Morvan

    2009-01-01

    The aim of this preliminary study was to evaluate the role of the cell wall in Zn accumulation and tolerance by tomato suspension-cultured\\u000a cells. Growth parameters, Zn distribution and accumulation by tomato cells were determined in function of zinc concentration.\\u000a A particular attention was paid to the variations of the total cell wall material (cell wall carbohydrates, proteins, and\\u000a exopolymers)

  4. 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.

  5. Solar cell encapsulation

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

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

  6. Solar cell design study

    Microsoft Academic Search

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

    1977-01-01

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

  7. High efficiency large area solar cells using microcrystalline silicon

    Microsoft Academic Search

    K. Saito; M. Sano; H. Otoshi; A. Sakai; S. Okabe; K. Ogawa

    2003-01-01

    We made a substrate type triple junction solar cell by using roll-to-roll PCVD machines. The triple junction solar cell consists of stainless steel substrate, silver (Ag)\\/zinc oxide (ZnO) back reflector, microcrystalline silicon (\\/spl mu\\/c-Si) bottom cell, microcrystalline silicon middle cell, amorphous silicon (a-Si) top cell, transparent conductive oxide layer (TCO), positive electrode and transparent hard coat layer. Microcrystalline silicon intrinsic

  8. Porphyrin-sensitized solar cells.

    PubMed

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

    2013-01-01

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

  9. Fundamentals of solar cells

    Microsoft Academic Search

    A. L. Farhenbruch; R. H. Bube

    1983-01-01

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

  10. 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.

  11. 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.

  12. 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. [Georgia Inst. of Tech., Atlanta, GA (United States)

    1992-10-01

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

  13. A dual power cell for storing electricity in zinc metal

    NASA Astrophysics Data System (ADS)

    Zhang, Gregory X.

    2015-07-01

    This article reports a novel electrochemical cell system for storing electrical energy in zinc metal. In this system the cell is structured with three distinctive sections for energy absorption, storage and delivery. The energy is absorbed into zinc metal through electro deposition in the top section and is delivered through zinc dissolution in the bottom section. The zinc metal is contained in the middle section between the sections for deposition and dissolution. Because the zinc metal is contained separately from the electrodes this system allows storage of energy at a low cost. Also, having deposition and dissolution of zinc in separate spaces allows independent operation of charging and discharging. This cell is capable receiving and outputting power at the same time, based on which it is thus termed as a dual power cell. The cell design and results of the prototype testing are reported. The characteristics, potential applications and cost of stored electricity of the system are also discussed.

  14. Lateral superlattice solar cells

    Microsoft Academic Search

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

    1997-01-01

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

  15. Intermediate band solar cells

    Microsoft Academic Search

    Antonio Marti

    2010-01-01

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

  16. Thermal design requirements of a 50kW zinc\\/redox flow battery for solar electrical energy storage

    Microsoft Academic Search

    J. R. Selman; H. Wu; R. P. Hollandsworth

    1985-01-01

    The conceptual engineering design of a large-scale zinc\\/redox battery for solar electrical energy storage involves the management of considerable heat flows. This is due to the large heat-of-crystallization of sodium ferrocyanide decahydrate produced during discharge, as well as the usual reversible and irreversible cell-reaction heat effects. A discussion of practical design implications is presented.

  17. Thermal design requirements of a 50kW zinc\\/redox flow battery for solar electrical energy storage

    Microsoft Academic Search

    J. R. Selman; H. Wu; R. P. Hollandsworth

    1984-01-01

    The conceptual engineering design of a large scale zinc\\/redox battery for solar electrical energy storage involves the management of considerable heat flows. This is due to the large heat of crystallization of sodium ferrocyanide decahydrate produced during discharge as well as the usual reversible and irreversible cell reaction heat effects. A discussion of practical design implications is presented.

  18. 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. [Georgia Inst. of Tech., Atlanta, GA (United States)

    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.

  19. Inhibitory Effect of Zinc on Human Prostatic Carcinoma Cell Growth

    PubMed Central

    Liang, Ji-Yong; Liu, Yi-Yan; Zou, Jing; Franklin, Renty B.; Costello, Leslie C.; Feng, Pei

    2015-01-01

    BACKGROUND Normal human prostate accumulates the highest levels of zinc of any soft tissue in the body. In contrast, the zinc level in prostate cancer is markedly decreased from the level detected in nonprostate tissues. Despite these relationships, the possible role of zinc in the growth of normal and malignant prostate has not been determined. METHODS Growth inhibition and various regulatory responses were investigated in two human prostate carcinoma cell lines (LNCaP and PC-3), treated with or without zinc. RESULTS Incubation of the prostate carcinoma cell lines with physiological levels of zinc resulted in the marked inhibition of cell growth. A lower 50% inhibition of cell growth (IC50) value for zinc (about 100 ng/ml) was detected in LNCaP cells, which are androgen-responsive, whereas androgen-independent PC-3 cells exhibited a higher IC50 for zinc (about 700 ng/ml). Incubation with 1 ?g/ml zinc resulted in maximum inhibition of growth in both cell lines. These inhibitory effects of zinc correlated well with the accumulation of zinc in the cells. Simultaneously, cell flow cytometric analyses revealed a dramatic increase of the cell population in G2/M phase, in both LNCaP (2.3-fold vs. control) and PC-3 (1.9-fold vs. control), and a decreased proportion of cells in S phase (LNCaP, ?51.4%; PC-3, ?23%), indicating a G2/M phase arrest. The cell growth inhibition and G2/M arrest in these cells were accompanied by an increase in apoptosis, as demonstrated by the characteristic cell morphology and further confirmed by cellular DNA fragmentation. The specificity of zinc-induced apoptosis was identified by ethylenediamine-tetraacetic acid (EDTA)-chelation, which abolished the zinc effect on cellular DNA fragmentation. The zinc-induced G2/M phase arrest and apoptosis were accompanied by increased mRNA levels of p21Waf1/Cip1/Sdi1 in both LNCaP (p53+/+) and PC-3 (p53?/?) cells. CONCLUSIONS These results suggest that zinc inhibits human prostatic carcinoma cell growth, possibly due to induction of cell cycle arrest and apoptosis. There now exists strong evidence that the loss of a unique capability to retain high levels of zinc is an important factor in the development and progression of malignant prostate cells. PMID:10398282

  20. 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.

  1. Investigation of surface phase formation during tin-rich growth of Copper2ZincTinSulfer4 polycrystlalline thin films for solar cells

    NASA Astrophysics Data System (ADS)

    Bolke, Joseph Glenn

    Cu2ZnSnS4 (CZTS) is a semiconductor material made of nontoxic, earth abundant elements, making it a promising topic of research for absorber layers in thin film solar cells. We observed that rapid thermal annealing of tin (Sn)-rich co-sputtered CZTS films resulted in crystalline, hexagonal platelets of tin-disulfide (SnS2) 5-30 µm long at the surface of the film. In this work, the formation mechanisms of these surface crystallites and their implications for CZTS absorber layer processing were investigated. The formation and decomposition of these platelets were studied by observing the changes in their structural, morphological, compositional, and vibrational properties accompanying the imposition of lateral temperature gradients as well as different annealing atmospheres. The homogeneous co-sputtered films were annealed in a graphite boat in a quartz reactor using a base heater and halogen lamp. Interrupting annealings to examine stages of crystal formation showed at around 400 °C SnS2 began to form on the surface of films. Near the edges of the film, where temperatures were found to be higher, crystals melted into an amorphous unknown tin-sulfide phase. Diffusion of species from the film into the base of the crystals formed long CZTS grains of which the amorphous phase left behind as it coalesced. Annealing without sulfur (S) increased Sn and S losses from the film and increased the number of crystals nucleated on the surface of the film. For solar cell device applications of CZTS thin films, removal of these SnS2 surface crystallites is necessary; thus wet chemical and thermal decomposition etching techniques were studied. Wet etching attempts with KCN and NH4OH solutions did little to etch crystals. HCl solution damaged the CZTS film as much as the crystals and therefore was also unsuitable. Thermal etching by evacuating the chamber near the end of annealing transformed the SnS2 crystals into a grainy, S-poor Sn phase via the decomposition of SnS2 by removing the vapor species with which it is in equilibrium. Understanding the role of Sn species during annealing is important for the complex CZTS system because small deviations from Sn stoichiometry results in drastic changes in the secondary phases and microstructure of the film. The experiments and insight provided in this thesis represent unexplored unconventional methods toward CZTS growth and different approaches for CZTS processing for development of thin film solar cell technology.

  2. 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.

  3. Zinc and silver migration during rechargeable silver-zinc cell cycling

    Microsoft Academic Search

    Harlan L. Lewis; Steven P. Wharton

    1997-01-01

    A study has been established to obtain zinc and silver migration rate data on cellulosic separators derived from a variety of cellulose and cellophane sources in silver-zinc alkaline rechargeable cells. The purpose of the study is to utilize the cycle and wet life data which are, in part, a function of the formation of soft and hard shorting in the

  4. NREL scientists develop robust, high-performance IZO transparent contact for CIGS solar cells.

    E-print Network

    NREL scientists develop robust, high-performance IZO transparent contact for CIGS solar cells indium gallium diselenide (CIGS) solar cell is zinc oxide (ZnO). The problem is that unprotected Zn improve humidity resistance in CIGS solar cells. Key Result This new method yields increased product

  5. Dye-Sensitized Solar Cells DOI: 10.1002/anie.201104786

    E-print Network

    Lin, Zhiqun

    Dye-Sensitized Solar Cells DOI: 10.1002/anie.201104786 Low-Cost Copper Zinc Tin Sulfide Counter Electrodes for High- Efficiency Dye-Sensitized Solar Cells** Xukai Xin, Ming He, Wei Han, Jaehan Jung, and Zhiqun Lin* Dye-sensitized solar cells (DSSCs) are among the most promising photovoltaic devices for low

  6. 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

  7. Lateral superlattice solar cells

    SciTech Connect

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

    1997-04-01

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

  8. Lateral superlattice solar cells

    SciTech Connect

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

    1997-10-01

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

  9. Properties of double-layered Ga-doped Al-zinc-oxide/titanium-doped indium-tin-oxide thin films prepared by dc magnetron sputtering applied for Si-based thin film solar cells

    SciTech Connect

    Wang, Chao-Chun; Wuu, Dong-Sing; Lin, Yang-Shih; Lien, Shui-Yang; Huang, Yung-Chuan; Liu, Chueh-Yang; Chen, Chia-Fu; Nautiyal, Asheesh; Lee, Shuo-Jen [Department of Materials Science and Engineering, National Chung Hsing University, Taichung 40227, Taiwan (China); Department of Materials Science and Engineering, MingDao University, Changhua 52345, Taiwan (China); Department of Mechanical Engineering, Yuan Ze University, Taoyuan 320, Taiwan (China)

    2011-11-15

    In this article, Ga-doped Al-zinc-oxide (GAZO)/titanium-doped indium-tin-oxide (ITIO) bi-layer films were deposited onto glass substrates by direct current (dc) magnetron sputtering. The bottom ITIO film, with a thickness of 200 nm, was sputtered onto the glass substrate. The ITIO film was post-annealed at 350 deg. C for 10-120 min as a seed layer. The effect of post-annealing conditions on the morphologies, electrical, and optical properties of ITIO films was investigated. A GAZO layer with a thickness of 1200 nm was continuously sputtered onto the ITIO bottom layer. The results show that the properties of the GAZO/ITIO films were strongly dependent on the post-annealed conditions. The spectral haze (T{sub diffuse}/T{sub total}) of the GAZO/ITIO bi-layer films increases upon increasing the post-annealing time. The haze and resistivity of the GAZO/ITIO bi-layer films were improved with the post-annealed process. After optimizing the deposition and annealing parameters, the GAZO/ITIO bi-layer film has an average transmittance of 83.20% at the 400-800 nm wavelengths, a maximum haze of 16%, and the lowest resistivity of 1.04 x 10{sup -3}{Omega} cm. Finally, the GAZO/ITIO bi-layer films, as a front electrode for silicon-based thin film solar cells, obtained a maximum efficiency of 7.10%. These encouraging experimental results have potential applications in GAZO/ITIO bi-layer film deposition by in-line sputtering without the wet-etching process and enable the production of highly efficient, low-cost thin film solar cells.

  10. Quantum dot solar cells

    Microsoft Academic Search

    A. J Nozik

    2002-01-01

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

  11. 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.

  12. 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

  13. Photovoltaic solar cell

    DOEpatents

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

    2013-11-26

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

  14. 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.

  15. 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.

  16. 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.

  17. Lateral superlattice solar cells

    Microsoft Academic Search

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

    1997-01-01

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

  18. Thin silicon solar cells

    SciTech Connect

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

    1992-12-01

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

  19. 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.

  20. Effects of number and position of meta and para carboxyphenyl groups of zinc porphyrins in dye-sensitized solar cells: structure-performance relationship.

    PubMed

    Ambre, Ram B; Mane, Sandeep B; Chang, Gao-Fong; Hung, Chen-Hsiung

    2015-01-28

    Porphyrin sensitizers containing meta- and para-carboxyphenyl groups in their meso positions have been synthesized and investigated for their performance in dye-sensitized solar cells (DSSCs). The superior performance of para-derivative compared to meta-derivative porphyrins was revealed by optical spectroscopy, electrochemical property measurements, density functional theory (DFT) calculations, attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, incident photon-to-current conversion efficiency (IPCE), electrochemical impedance spectroscopy (EIS), and stability performance. Absorption spectra of para-carboxyphenyl-substituted porphyrins on TiO2 show a broader Soret band compared to meta-carboxyphenyl-substituted porphyrins. ATR-FTIR spectra of the studied porphyrins on TiO2 were applied to investigate the number and mode of carboxyl groups attached to TiO2. The VOC, JSC, and IPCE values of para-series porphyrins were distinctly superior to those of meta-series porphyrins. The Nyquist plots of the studied porphyrins show that charge injection in para-series porphyrins is superior to that in meta-series porphyrins. The orthogonally positioned para derivatives have more efficient charge injection and charge transfer over charge recombination, whereas the efficiencies of flat-oriented meta derivatives are retarded by rapid charge recombination. Photovoltaic measurements of the studied meta- and para-carboxyphenyl-functionalized porphyrins show that the number and position of carboxyphenyl groups play a crucial role in the performance of the DSSC. Our results indicate that para-carboxyphenyl derivatives outperform meta-carboxyphenyl derivatives to give better device performance. This study will serve as a guideline for the design and development of organic, porphyrin, and ruthenium dyes in DSSCs. PMID:25562465

  1. EE580 Solar Cells Todd J. Kaiser

    E-print Network

    Kaiser, Todd J.

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

  2. Separation composition evaluation in model rechargeable silver-zinc cells

    Microsoft Academic Search

    H. Lewis; S. Henderson; T. Danko

    2001-01-01

    In previous reports, the evaluation of Viskase sausage casings (SCs) in a variety of configurations for silver\\/zinc rechargeable cells has been reported. The conclusions have been that several layers of SC, while providing improved resistance to silver migration acid zinc dendrite growth compared to standard cellophane film, also impart increased internal impedance which leads to faster capacity loss in comparison

  3. 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.

  4. Transparent solar cell module

    NASA Technical Reports Server (NTRS)

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

    1979-01-01

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

  5. Human ZIP1 is a major zinc uptake transporter for the accumulation of zinc in prostate cells

    PubMed Central

    Franklin, R.B.; Ma, J.; Zou, J.; Guan, Z.; Kukoyi, B.I.; Feng, P.; Costello, L.C.

    2015-01-01

    The prostate gland of humans and other animals accumulates a level of zinc that is 3–10 times greater than that found in other tissues. Associated with this ability to accumulate zinc is a rapid zinc uptake process in human prostate cells, which we previously identified as the hZIP1 zinc transporter. We now provide additional evidence that hZIP1 is an important operational transporter that allows for the transport and accumulation of zinc. The studies reveal that hZIP1 (SLC39A1) but not hZIP2 (SLC39A2) is expressed in the zinc-accumulating human prostate cell lines, LNCaP and PC-3. Transfected PC-3 cells that overexpress hZIP1 exhibit increased uptake and accumulation of zinc. The Vmax for zinc uptake was increased with no change in Km. Along with the increased intracellular accumulation of zinc, the overexpression of hZIP1 also results in the inhibition of growth of PC-3 cells. Down-regulation of hZIP1 by treatment of PC-3 cells with hZIP1 antisense oligonucleotide resulted in a decreased zinc uptake. Uptake of zinc from zinc chelated with citrate was as rapid as from free zinc ions; however, the cells did not take up zinc chelated with EDTA. The cellular uptake of zinc is not dependent upon an available pool of free Zn2+ ions. Instead, the mechanism of transport appears to involve the transport of zinc from low molecular weight ligands that exist in circulation as relatively loosely bound complexes with zinc. PMID:12888280

  6. 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.

  7. Solar cell radiation damage

    Microsoft Academic Search

    R. L. Crabb

    1994-01-01

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

  8. Flexible dye solar cells

    Microsoft Academic Search

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

    2004-01-01

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

  9. Amorphous silicon solar cells

    Microsoft Academic Search

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

    1981-01-01

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

  10. Amorphous silicon solar cells

    Microsoft Academic Search

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

    1983-01-01

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

  11. Silicon for solar cells

    NASA Astrophysics Data System (ADS)

    Ciszek, T. F.

    1984-04-01

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

  12. 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...

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

    Microsoft Academic Search

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

    2008-01-01

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

  14. 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.

  15. 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.

  16. Zinc and silver migration during rechargeable silver-zinc cell cycling

    SciTech Connect

    Lewis, H.L.; Wharton, S.P. [Naval Surface Warfare Center, Crane, IN (United States)

    1997-12-01

    A study has been established at NAVSURFWARCENDIV Crane to obtain zinc and silver migration rate data on cellulosic separators derived from a variety of cellulose and cellophane sources, in silver-zinc alkaline rechargeable cells. These data are to be related to cycle and wet life data from the model electrochemical cells as a function of separator composition for the rechargeable cell set. The first examples used in this program are cells of 28 Ahr capacity, identical in every respect except for the separator composition, which are being tested in statistically significant numbers under identical temperature and relative humidity conditions, with 45% KOH as the electrolyte. The cycle life test regime is C/5 discharge to 1.30 V and C/30 and C/60 charge to 2.03 V continuous cycling, while the wet life test regime includes a 30-day wet stand at full charge between cycles. At the outset of the cell testing, a baseline cell was selected from each set in the matrix after the formation cycling was complete, and the silver and zinc migration through successive separator layers were determined. Also, at intervals during life cycle and wet life, and as cells fail the life tests, the measurements will be repeated. In this way a correlation may be established between silver and zinc migration rates under charge discharge conditions in actual cells and the cycle and wet life of the respective cell types. Eight separator compositions, all cellulose-based, are being evaluated. The purpose of the study is to utilize the cycle and wet life data to designate a best separator for incorporation into actual production cells. The recommendations will take the form of minimum separator physical properties which are beneficial to cell performance and long life, resulting in an improvement in the assets available for Navy Fleet use. This paper will discuss the data available on silver and zinc migration and their relationship to cell cycling at several stages during the cell life.

  17. 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.

  18. 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.

  19. Effect of zinc supplementation on incidence of infections and hospital admissions in sickle cell disease (SCD)

    Microsoft Academic Search

    Ananda S. Prasad; Frances W. J. Beck; Joseph Kaplan; Pranatharthi H. Chandrasekar; Jesus Ortega; James T. Fitzgerald; Paul Swerdlow

    1999-01-01

    Zinc deficiency is a common nutritional problem in adult sickle-cell disease (SCD) pa- tients. Hyperzincuria and increased requirement of zinc due to continued hemolysis in SCD are probable bases for zinc deficiency in these patients. Zinc deficiency affects adversely T-helper1 (TH1) functions and cell mediated immunity and interleukin (IL)-2 production is decreased in zinc deficient subjects. We hypothesized that zinc

  20. Transparent electrode materials for solar cells

    NASA Astrophysics Data System (ADS)

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

    2008-04-01

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

  1. 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.

  2. Potential for use of InP solar cells in the space radiation environment

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    Indium phosphide solar cells were observed to have significantly higher radiation resistance than either GaAs or Si after exposure to 10 MeV proton irradiation data and previous 1 MeV electron data together with projected efficiencies for InP, it was found that these latter cells produced more output power than either GaAs or Si after specified fluences of 10 MeV protons and 1 MeV electrons. Estimates of expected performance in a proton dominated space orbit yielded much less degradation for InP when compared to the remaining two cell types. It was concluded that, with additional development to increase efficiency, InP solar cells would perform significantly better than either GaAs or Si in the space radiation environment.

  3. Effects of Dye Loading Conditions on the Energy Conversion Efficiency of ZnO and TiO2 Dye-Sensitized Solar Cells

    E-print Network

    Cao, Guozhong

    light conversion efficiency of zinc oxide (ZnO) film electrodes in dye-sensitized solar cellsO) has been explored as an alternative material in dye-sensitized solar cells. The use of Zn as an alternative material for improving the solar cell performance in dye-sensitized solar cells due to (1) Zn

  4. Systems analysis of Mars solar electric propulsion vehicles

    Microsoft Academic Search

    J. M. Hickman; H. B. Curtis; B. H. Kenny; R. J. Sefcik

    1990-01-01

    Mission performance, mass, initial power, and cost are determined for solar electric propulsion vehicles across a range of payload masses, reference powers, and mission trajectories. Thick radiation shielding is added to arrays using indium phosphide or III-V multijunction solar cells to reduce the damage incurred through the radiation belts. Special assessments of power management and distribution systems, atmospheric drag, and

  5. 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

  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. Zinc transporter gene expression is regulated by pro-inflammatory cytokines: a potential role for zinc transporters in beta-cell apoptosis?

    Microsoft Academic Search

    Lærke Egefjord; Jens Jensen; Claus Heiner Bang-Berthelsen; Andreas Petersen; Kamille Smidt; Ole Schmitz; Allan Ertman Karlsen; Flemming Pociot; Fabrice Chimienti; Jørgen Rungby; Nils E Magnusson

    2009-01-01

    BACKGROUND: ?-cells are extremely rich in zinc and zinc homeostasis is regulated by zinc transporter proteins. ?-cells are sensitive to cytokines, interleukin-1? (IL-1?) has been associated with ?-cell dysfunction and -death in both type 1 and type 2 diabetes. This study explores the regulation of zinc transporters following cytokine exposure. METHODS: The effects of cytokines IL-1?, interferon-? (IFN-?), and tumor

  8. 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.

  9. Nanostructured SIS solar cells

    NASA Astrophysics Data System (ADS)

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

    2010-05-01

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

  10. Very high efficiency solar cells

    NASA Astrophysics Data System (ADS)

    Barnett, Allen; Kirkpatrick, Douglas; Honsberg, Christiana

    2006-08-01

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

  11. Solar PV- How A Solar Cell Works

    NSDL National Science Digital Library

    Levander, Alejandro

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

  12. Quantum Dot Solar Cells

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

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

  13. Solar-Cell String Conveyor

    NASA Technical Reports Server (NTRS)

    Frasch, W.; Ciavola, S.

    1982-01-01

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

  14. Compound polycrystalline solar cells

    Microsoft Academic Search

    Robert W. Birkmire

    2001-01-01

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

  15. Nanocrystalline electrochemical solar cells

    SciTech Connect

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

    1994-12-31

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

  16. Solar cells - A technology assessment

    Microsoft Academic Search

    J. R. Bolton

    1983-01-01

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

  17. Zinc-oxygen primary cell yields high energy density

    NASA Technical Reports Server (NTRS)

    Graff, C. B.

    1968-01-01

    Zinc-oxygen primary cell yields high energy density for battery used as an auxiliary power source in space vehicle systems. Maximum reliability and minimum battery weight is achieved by using a stacking configuration of 23 series-connected modules with 6 parallel-connected cells per module.

  18. Advancing tandem solar cells by spectrally selective multilayer intermediate reflectors.

    PubMed

    Hoffmann, Andre; Paetzold, Ulrich W; Zhang, Chao; Merdzhanova, Tsvetelina; Lambertz, Andreas; Ulbrich, Carolin; Bittkau, Karsten; Rau, Uwe

    2014-08-25

    Thin-film silicon tandem solar cells are composed of an amorphous silicon top cell and a microcrystalline silicon bottom cell, stacked and connected in series. In order to match the photocurrents of the top cell and the bottom cell, a proper photon management is required. Up to date, single-layer intermediate reflectors of limited spectral selectivity are applied to match the photocurrents of the top and the bottom cell. In this paper, we design and prototype multilayer intermediate reflectors based on aluminum doped zinc oxide and doped microcrystalline silicon oxide with a spectrally selective reflectance allowing for improved current matching and an overall increase of the charge carrier generation. The intermediate reflectors are successfully integrated into state-of-the-art tandem solar cells resulting in an increase of overall short-circuit current density by 0.7 mA/cm(2) in comparison to a tandem solar cell with the standard single-layer intermediate reflector. PMID:25322181

  19. 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.

  20. An algebraic model for a zinc/bromine flow cell 

    E-print Network

    Simpson, Gary Don

    1988-01-01

    AN ALGEBRAIC MODEL FOR A ZINC/BROMINE FLOW CELL A Thesis by GARY DON SIMPSON Submitted to the Graduate College of Texas A & M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE August 1988 Major... Subject: Chemical Engineering AN ALGEBRAIC MODEL OF A ZINC/BROMINE FLOW CELL A Thesis GARY DON SIMPSON Approved as to style and content by: R. E. White (Chairman of Committee) A. T. Watson (Member) R. B. G (Member R. W. Flumerfelt (Head...

  1. Solar cell module lamination process

    DOEpatents

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

    2002-01-01

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

  2. Characterization of Zinc Influx Transporters (ZIPs) in Pancreatic ? Cells: ROLES IN REGULATING CYTOSOLIC ZINC HOMEOSTASIS AND INSULIN SECRETION.

    PubMed

    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

    2015-07-24

    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

  3. 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.

  4. Radiative cooling for solar cells

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

  5. 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...

  6. On-orbit results of the LIPS 3/InP homojunction solar cell experiment

    NASA Technical Reports Server (NTRS)

    Brinker, David J.

    1989-01-01

    The flight performance of NASA Lewis Research Center's indium phosphide homojunction solar cell module on the LIPS 3 satellite is presented. A module of four n+p cells was fabricated and has been on-orbit on the LIPS 3 spacecraft since 1987. The experimental objective is the measurement of InP cell performance in the natural radiation environment of the 1100 kilometer altitude, 60 deg inclination, circular orbit. Flight data from the first year is near expected values, with no degradation in short-circuit current. The temperature dependence of current-voltage parameters is included along with the laboratory radiation tolerance studies necessary for normalization and analysis of the data. Details of the cell structure and flight module design are also discussed.

  7. High intensity solar cells

    SciTech Connect

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

    1986-01-01

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

  8. Thin film solar cell workshop

    NASA Technical Reports Server (NTRS)

    Armstrong, Joe; Jeffrey, Frank

    1993-01-01

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

  9. Comparative in vitro toxicity of seven zinc-salts towards neuronal PC12 cells.

    PubMed

    Pavlica, Sanja; Gaunitz, Frank; Gebhardt, Rolf

    2009-06-01

    Currently much attention has been given to the neurotoxicity of zinc, yet little is known about the influence of the counterions present. Therefore, we investigated the influence of different Zn(2+)-salts (concentrations range 0.05-0.3 mM) on cell viability, ATP and glutathione concentration and caspase activation in differentiated PC12 cells as a model for neuronal cells. Generally, at concentrations of 0.05 mM most Zn(2+)-salts were not cytotoxic except for zinc-citrate. At concentrations between 0.1 and 0.3 mM Zn(2+) a significant decrease in GSH and ATP levels preceded cell death induced by all salts, except of zinc-histidinate. Zinc-citrate and zinc-sulphate turned out to be the most toxic salts particularly at low concentrations. Analyses of caspase 3/7 activity showed that dependent on the concentration and the type of the salt used cell death may show more or less signs of both, necrosis and apoptosis. Interestingly, the uptake of Zn(2+) from zinc-sulphate and zinc-citrate was significantly higher than that of other salts, implicating a correlation between uptake and toxicity. In conclusion, Zn(2+)-salts could be divided into three categories with high (zinc-citrate, zinc-sulphate), moderate (zinc-orotate, zinc-acetate, zinc-chloride(,) zinc-gluconate) and low cytotoxicity (zinc-histidinate). PMID:19306923

  10. 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.

  11. 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

  12. 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 ...

  13. Thermomechanical stressing of solar cells

    Microsoft Academic Search

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

    2006-01-01

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

  14. 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…

  15. Thin monocrystalline silicon solar cells

    SciTech Connect

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

    1999-10-01

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

  16. 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.

  17. InP shallow-homojunction solar cells

    NASA Technical Reports Server (NTRS)

    Keavney, Christopher; Spitzer, Mark B.; Vernon, Stanley M.; Haven, Victor E.; Augustine, Godfrey

    1989-01-01

    Indium phosphide solar cells with very thin n-type emitters have been made by both ion implantation and metalorganic chemical vapor deposition. Air mass zero efficiencies as high as 18.8 percent (NASA measurement) have been achieved. Although calculations show that, as is the case with GaAs, a heterostructure is expected to be required for the highest efficiencies attainable, the material properties of InP give the shallow-homojunction structure a greater potential than in the case of GaAs. The best cells, which were those made by ion implantation, show open-circuit voltage (V sub oc) of 873 mV, short-circuit current of 357 A/sq m (35.7 mA/sq cm), and fill factor of 0.829. Improvements are anticipated in all three of these parameters. Internal quantum efficiency peaks at over 90 percent in the red end of the spectrum, but drops to 54 percent in the blue end. Other cells have achieved 74 percent in the blue end. Detailed modeling of the data indicates that a high front surface recombination velocity is responsible for the low blue response, that the carrier lifetime is high enough to allow good carrier collection from both the base and the emitter, and that the voltage is base-limited.

  18. Zinc

    MedlinePLUS

    ... and loss of appetite. Weight loss, problems with wound healing, decreased ability to taste food, and lower alertness ... the health problems discussed below. Immune system and wound healing The body's immune system needs zinc to do ...

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

    NASA Astrophysics Data System (ADS)

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

    1993-05-01

    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.

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

    Microsoft Academic Search

    B. Mazhari

    2006-01-01

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

  1. New Materials for Chalcogenide Based Solar Cells

    NASA Astrophysics Data System (ADS)

    Tosun, Banu Selin

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

  2. 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...

  3. Back wall solar cell

    NASA Technical Reports Server (NTRS)

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

    1978-01-01

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

  4. Germanium Nanocrystal Solar Cells

    NASA Astrophysics Data System (ADS)

    Holman, Zachary Charles

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

  5. Bulb mounting of solar cell

    SciTech Connect

    Thompson, M.E.

    1983-04-05

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

  6. Zinc uptake into endothelial cells involves a carrier mediated component

    Microsoft Academic Search

    D. J. Bobilya; M. Briske-Anderson; P. G. Reeves

    1991-01-01

    The mechanism of zinc (Zn) uptake by endothelial cells was examined. Bovine pulmonary endothelial cells were grown to a confluent monolayer in T-25 flasks with minimum essential medium (MEM) containing 10% fetal bovine serum. Zn uptake was studied by replacing the growth medium with experimental media of MEM, 14% EDTA dialyzed serum, and 250 nCi ⁶⁵Zn\\/mL. The transport mechanism was

  7. Performance of porous plastic separators in zinc/bromine cells

    NASA Astrophysics Data System (ADS)

    Cathro, K. J.; Constable, D. C.; Hoobin, P. M.

    1988-01-01

    Bromine transport through various acetone-extracted microporous plastic materials is studied with attention given to their use as separators in zinc/bromine cells. Given the porosity and tortuosity of the materials, the samples that were acetone-extracted and then either air-dried or hot-water-quenched showed equivalent thicknesses were far less than would be expected. The measured faradaic efficiencies of cells are in good agreement with those calculated from the bromine transport properties of the chosen separators.

  8. Evidence for Operation of the Direct Zinc Ligand Exchange Mechanism for Trafficking, Transport, and Reactivity of Zinc in Mammalian Cells

    PubMed Central

    Costello, Leslie C.; Fenselau, Catherine C.; Franklin, Renty B.

    2011-01-01

    In addition to its critical role in normal cell function, growth, and metabolism, zinc is implicated as a major factor in the development and progression of many pathological conditions and diseases. Despite this importance of zinc, many important factors, processes, and mechanisms of the physiology, biochemistry, and molecular biology of zinc remain unknown. Especially important is the unresolved issue regarding the mechanism and process of the trafficking, transport, and reactivity of zinc in cells; especially in mammalian cells. This presentation focuses on the concept that, due to the existence of a negligible pool of free Zn2+ ions in the mammalian cell environment, the trafficking, transport and reactivity of zinc occurs via a direct exchange of zinc from donor Zn-Ligands to acceptor ligands. This Zn exchange process occurs without the requirement for production of free Zn2+ ions. The direct evidence from mammalian cell studies is presented in support of the operation of the direct Zn-Ligand exchange mechanism. The paper also provides important information and conditions that should be considered and employed in the conduct of studies regarding the role and effects of zinc in biological/biomedical research; and in its clinical interpretation and application. PMID:21440525

  9. Thin monocrystalline silicon solar cells

    Microsoft Academic Search

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

    1999-01-01

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

  10. Transporting Solar-Cell Strings

    NASA Technical Reports Server (NTRS)

    Bycer, M.; Frasch, W.

    1982-01-01

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

  11. 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

  12. 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.

  13. Zinc electrowinning analysis in a modified Hull cell

    NASA Astrophysics Data System (ADS)

    McColm, Thomas Dean

    The Hull cell is an analytical cell designed with trapezoidal geometry to incorporate a range of current densities into a single experiment. It was conceived to examine electroplating processes rather than mass production processes. A modified analytical cell was designed, developed and applied to the diagnosis of zinc electrowinning. Emphasis was placed on obtaining the quantitative variation of current efficiency with current density and the associated microscopic variation in deposit morphology. Current density distributions came by placing an insulating baffle in between parallel electrodes. The baffle position and length were easily adjusted, allowing the generation of 12 different distributions for a single applied potential. Ten electrically isolated 1 cm2 segments comprised the cathode. Measurement of the potential drop across I ohm resistors in each of the ten isolated parallel branches permitted direct quantitative determination of current densities. The small segments permitted simple SEM and X-ray analysis of deposits. The cell was designed to allow the continual cycling of electrolyte. In conjunction with experimental analysis, a technique for the determination of current efficiency was tested and developed. The technique involved the comparison of charge passed for the electrodeposition and subsequent electrodissolution of a given mass of zinc and removed the necessity to determine the mass directly. In no prior studies on zinc electrowinning had current efficiencies been determined this way. The cell and technique were developed and verified by the correct diagnosis of industrial zinc electrowinning. Successful determination of the effects of key variables including temperature, acid to zinc ratio and impurity effects on current efficiency and deposit morphology was demonstrated. In parallel with experimental work, cell electrochemistry was modeled. Primary and secondary input parameters were those pertinent to zinc electrowinning. The resultant simulation served as a design aid to investigate the effect of implementing changes in key process variables and cell geometry. Custom software using pattern recognition and numerical integration to determine current densities and efficiencies directly from logged data was designed, written and interfaced with data acquisition software. The resulting experimental system serves as an unprecedented bench top scale, analytical tool tailored specifically for the electrowinning industry.

  14. Effect of thermal conductivity on the efficiency of single crystal silicon solar cell coated with an anti-reflective thin film

    Microsoft Academic Search

    F. M. Gaitho; F. G. Ndiritu; P. M. Muriithi; R. G. Ngumbu; J. K. Ngareh

    2009-01-01

    This paper presents the working of a single crystal silicon solar cell coated with a zinc oxide thin film. Single crystalline silicon is the absorber of incident solar radiation, while the zinc oxide film – an optically black film, offers optical improvement. Thermal conductivity measurements were made using the transient line heat source (TLHS) method, where the heat source is

  15. Laser processing of solar cells

    NASA Astrophysics Data System (ADS)

    Carlson, David E.

    2012-10-01

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

  16. 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.

  17. 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.

  18. Fundamental studies of the metallurgical, electrical, and optical properties of gallium phosphide and gallium phosphide alloys

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Abstracts, bibliographic data, oral presentations, and published papers on (1) Diffusion of Sulfur in Gallium Phosphide and Gallium Arsenide, and (2) Properties of Gallium Phosphide Schottky Barrier Rectifiers for Use at High Temperature are presented.

  19. 24% efficient silicon solar cells

    Microsoft Academic Search

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

    1994-01-01

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

  20. 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.

  1. 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.

  2. Performance of zinc/bromine cells having a propionitrile electrolyte

    NASA Astrophysics Data System (ADS)

    Cathro, K. J.

    1988-07-01

    A study has been made of a small, zinc/bromine, circulated-electrolyte cell having a propionitrile-based electrolyte on the positive side and an aqueous electrolyte on the negative. It has been shown that the faradaic efficiency is approximately 50 percent when using a microporous plastic separator, but that this increases to nearly 90 percent if the separator is changed to a filter paper/microporous plastic compound type. A small, further increase in faradaic efficiency can be obtained by incorporating a quaternary ammonium bromide into the propionitrile phase. In addition, some information is presented on cell resistance and the effect of temperature and discharge current density on cell performance.

  3. Kinetic identification of a mitochondrial zinc uptake transport process in prostate cells

    PubMed Central

    Guan, Zhixin; Kukoyi, Boone; Feng, Pei; Kennedy, M. Claire; Franklin, Renty B.; Costello, Leslie C

    2015-01-01

    Prostate cells accumulate high cellular and mitochondrial concentrations of zinc, generally 3–10-fold higher than other mammalian cells. However, the mechanism of mitochondrial import and accumulation of zinc from cytosolic sources of zinc has not been established for these cells or for any mammalian cells. Since the cytosolic concentration of free Zn2+ ions is negligible (estimates vary from 10?9 to 10?15 M), we postulated that loosely bound zinc-ligand complexes (Zn-Ligands) serve as zinc donor sources for mitochondrial import. Zinc chelated with citrate (Zn-Cit) is a major form of zinc in prostate and represents an important potential cytosolic source of transportable zinc into mitochondria. The mitochondrial uptake transport of zinc was studied with isolated mitochondrial preparations obtained from rat ventral prostate. The uptake rates of zinc from Zn-Ligands (citrate, aspartate, histidine, cysteine) and from ZnCl2 (free Zn2+) were essentially the same. No zinc uptake occurred from either Zn-EDTA, or Zn-EGTA. Zinc uptake exhibited Michaelis–Menten kinetics and characteristics of a functional energy-independent facilitative transporter associated with the mitochondrial inner membrane. The uptake and accumulation of zinc from various Zn-Ligand preparations with log Kf (formation constant) values less than 11 was the same as for ZnCl2; and was dependent upon the total zinc concentration independent of the free Zn2+ ion concentration. Zn-Ligands with log Kf values grater than 11 were not zinc donors. Therefore the putative zinc transporter exhibits an effective log Kf~11 and involves a direct exchange of zinc from Zn-Ligand to transporter. The uptake of zinc by liver mitochondria exhibited transport kinetics similar to prostate mitochondria. The results demonstrate the existence of a mitochondrial zinc uptake transporter that exists for the import of zinc from cytosolic Zn-Ligands. This provides the mechanism for mitochondrial zinc accumulation from the cytosol which contains a negligible concentration of free Zn2+. The uniquely high accumulation of mitochondrial zinc in prostate cells appears to be due to their high cytosolic level of zinc-transportable ligands, particularly Zn-Cit. PMID:14512198

  4. Radiation effects in solar cells

    NASA Astrophysics Data System (ADS)

    Imaizumi, Mitsuru; Ohshima, Takeshi

    2013-05-01

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

  5. Research on multibandgap solar cells

    Microsoft Academic Search

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

    1987-01-01

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

  6. Multijunction amorphous silicon solar cells

    Microsoft Academic Search

    D. E. Carlson

    1991-01-01

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

  7. Zinc adaptation and resistance to cadmium toxicity in mammalian cells. Molecular insight by proteomic analysis.

    E-print Network

    Paris-Sud XI, Université de

    1 Zinc adaptation and resistance to cadmium toxicity in mammalian cells. Molecular insight Cedex 9, France. Tel: (33) 4 38 78 56 23, e-mail: jean-marc.moulis@cea.fr Abbreviations: HZR: High Zinc.1002/pmic.200701067 #12;2 ABSTRACT To identify proteins involved in cellular adaptive responses to zinc

  8. Induction of zinc transporters by forskolin in human trophoblast BeWo cells

    Microsoft Academic Search

    Nagayoshi Asano; Masuo Kondoh; Chiaki Ebihara; Makiko Fujii; Tsuyoshi Nakanishi; Naoki Utoguchi; Shuichi Enomoto; Keiichi Tanaka; Yoshiteru Watanabe

    2006-01-01

    During pregnancy, the zinc level in fetal serum is up to two-fold higher than that in the maternal serum at the end of pregnancy, but the mechanism of zinc release from the placenta into fetal circulation is not well understood. In this study, we determined the expression profiles of zinc transporters in human trophoblast BeWo cells, a representative human trophoblast

  9. Lead dioxide--zinc rechargeable-type cell and battery and electrolyte therefor

    Microsoft Academic Search

    Villarreal-Dominguez

    1976-01-01

    A lead dioxide--zinc rechargeable-type cell comprises at least one positive lead dioxide plate and at least one negative amalgamated zinc metal plate spaced from the positive plate and parallel to it. Both plates are permanently submerged in an aqueous acid electrolytee containing soluble zinc salts, a zinc surface-controlling agent, an electrolyte conductivity-correcting agent, and an amalgamating agent to prevent formation

  10. 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.

  11. Simulations of solar cell absorption enhancement using resonant modes of a nanosphere array

    E-print Network

    Grandidier, Jonathan

    cell structure featuring back reflector and anti-reflection coating. In addition, we use the full field solar cell structure featuring back reflector and optimized anti-reflection coating. We also use as represented in Fig. 1a. It is composed of a silver (Ag) back reflector, a 130-nm aluminum-doped zinc oxide

  12. Dye-sensitized Solar Cells for Solar Energy Harvesting

    Microsoft Academic Search

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

    2011-01-01

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

  13. Induction of type 1 interferon receptor by zinc in U937 cells

    Microsoft Academic Search

    Takeaki Nagamine; Kastuyuki Nakajima; Hisashi Takada; Yoshitaka Sekine; Kazuhiro Suzuki

    2009-01-01

    This study aims to determine whether zinc enhances interferon (IFN)-? activity in U937 cells. Type 1 IFN2 receptor (IFNAR2) protein in U937 cells was measured by flow cytometry. After 24h of exposure to zinc chloride or polaprezinc (a chelate of zinc and l-carnosine) at concentrations ranging from 50 to 200?M, histograms showing anti-IFNAR2 antibody-positive cells shifted to a higher FITC

  14. Solar cells with a twist Comments ( 35)

    E-print Network

    Rogers, John A.

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

  15. Space solar cells—tradeoff analysis

    Microsoft Academic Search

    M. Raja Reddy

    2003-01-01

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

  16. 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.

  17. Nanocrystal Solar Cells

    E-print Network

    Gur, Ilan

    2006-01-01

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

  18. Silicon concentrator solar cell research

    SciTech Connect

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

    1993-06-01

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

  19. Mononuclear cell metallothionein mRNA levels in human subjects with poor zinc nutrition.

    PubMed

    Kwon, Chong-Suk; Kountouri, Aggeliki M; Mayer, Claus; Gordon, Margaret-Jane; Kwun, In-Sook; Beattie, John H

    2007-02-01

    Human zinc deficiency is thought to be prevalent worldwide, particularly in populations with diets low in zinc and animal protein and high in inhibitors of zinc absorption, such as phytic acid. Confirmation of zinc deficiency is, however, difficult in the absence of a reliable and sensitive marker of zinc status. Under controlled conditions, T-lymphocyte metallothionein-2A (MT-2A) mRNA levels change in relation to zinc status and the objective of the present study was to investigate whether these transcript levels could be related to dietary zinc intake, plasma zinc or other biochemical parameters influenced by, or influencing, zinc metabolism in human subjects likely to be zinc deficient. Rural Koreans (n 110, age 50-80 years) with a range of zinc and phytic acid dietary intake were recruited for the study and blood samples were analysed for plasma zinc, HDL, LDL, alpha-tocopherol and thiobarbituric acid reactive substances, mononuclear cell (MNC) MT-2A mRNA, serum protein and albumin, and blood haematocrit, Hb and glucose. Multiple correlation and principal component analysis showed a significant negative correlation between plasma zinc and MNC MT-2A mRNA levels. Female subjects had higher MT-2A transcript levels than males and MT-2A mRNA levels tended to increase with age. There was no significant association between dietary zinc intake or any index of zinc intake relating to dietary inhibitors of zinc absorption. It is concluded that MNC MT-2A mRNA levels cannot be used to predict poor zinc nutrition. PMID:17298692

  20. Research of ZnS as a buffer layer for CIGS solar cells

    Microsoft Academic Search

    Hsin-Wei Huang; Sheng-Hui Chen; Cheng-Chung Lee

    2010-01-01

    Normally, CdS film is used as the buffer layer in the fabrication of copper indium gallium selenide solar cells. These solar cells can reach an efficiency of 10.3% when produced by a non-vacuum process. However, this is a very toxic process. In this study, we propose using a nontoxic zinc sulfide (ZnS) buffer layer which is deposited by chemical bath

  1. Histopathological changes in cases of aluminium phosphide poisoning.

    PubMed

    Sinha, U S; Kapoor, A K; Singh, A K; Gupta, A; Mehrotra, Ravi

    2005-04-01

    Of a total of 205 poisoning deaths in our hospital in 2003, 83 cases were due to Aluminium phosphide poisoning and were further analyzed. Most vulnerable age group was 21-40 years and M:F ratio was 2:1. On naked eye examination, almost all the vital organs were found to be congested. On microscopic study, the liver showed central venous congestion, degeneration, haemorrhage, sinusoidal dilation, bile stasis, centrilobular necrosis, Kupffer cell hyperplasia, infiltration by mononuclear cells and fatty change. Microscopy of the lungs revealed alveolar thickening, oedema, dilated capillaries, collapsed alveoli and haemorrhage. In the kidney, changes were degeneration, infiltration, tubular dilation and cloudy swelling. Changes in the brain included congestion and coagulative necrosis and in the stomach, congestion and haemorrhage. Easy availability of this cheap and highly toxic substance was responsible for the sudden spurt of poisoning with aluminium phosphide. PMID:16758658

  2. Nanosized zinc oxide particles induce neural stem cell apoptosis

    NASA Astrophysics Data System (ADS)

    Deng, Xiaoyong; Luan, Qixia; Chen, Wenting; Wang, Yanli; Wu, Minghong; Zhang, Haijiao; Jiao, Zheng

    2009-03-01

    Given the intensive application of nanoscale zinc oxide (ZnO) materials in our life, growing concerns have arisen about its unintentional health and environmental impacts. In this study, the neurotoxicity of different sized ZnO nanoparticles in mouse neural stem cells (NSCs) was investigated. A cell viability assay indicated that ZnO nanoparticles manifested dose-dependent, but no size-dependent toxic effects on NSCs. Apoptotic cells were observed and analyzed by confocal microscopy, transmission electron microscopy examination, and flow cytometry. All the results support the viewpoint that the ZnO nanoparticle toxicity comes from the dissolved Zn2+ in the culture medium or inside cells. Our results highlight the need for caution during the use and disposal of ZnO manufactured nanomaterials to prevent the unintended environmental and health impacts.

  3. Development of concentrator solar cells

    SciTech Connect

    Not Available

    1994-08-01

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

  4. (Melanin-Sensitized Solar Cell) : 696220016

    E-print Network

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

  5. Printing efficient solar cells

    Microsoft Academic Search

    Ritesh Tipnis; Darin Laird

    2008-01-01

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

  6. Growth and characterization of cadmium sulfide on indium phosphide using an RF atomic source and cadmium sulfide effusion cell

    NASA Astrophysics Data System (ADS)

    Choi, Joo Won

    InP provides the best lattice matched substrate for cadmium sulfide (0.63%). In our research, growth of CdS on InP (001) substrates is conducted using two different methods of molecular beam epitaxy (MBE). First, RF atomic source assisted growth, in which Cd is deposited from an effusion cell while sulfur is supplied from ionized hydrogen sulfide gas using an RF atomic source. An RF atomic source induces intense plasma in the pyrolytic boron nitride (PBN) crucible, resulting in the dissociation of H2S into H and S ions. The plasma intensity and emitted photon spectrum are monitored through a view port by a photodiode connected to a digital oscilloscope. Second, deposition is carried out using CdS sublimation from solid a CdS powder evaporation source. Both methods are carried out using an MBE system manufactured by Vacuum Generators (V80H). InP (001) substrate cleaning is performed prior to introduce to vacuum chamber. CdS layers were investigated by RHEED for film structure, atomic force microscopy (AFM) was use for surface morphology. Auger electro micro scopy (AES) was used for atomic concentration and film thickness. PL and X-ray diffraction system was used for film structure and crystallite size.

  7. Fabrication of boron-phosphide neutron detectors

    SciTech Connect

    Fitzsimmons, M.; Pynn, R.

    1997-07-01

    Boron phosphide is a potentially viable candidate for high neutron flux neutron detectors. The authors have explored chemical vapor deposition methods to produce such detectors and have not been able to produce good boron phosphide coatings on silicon carbide substrates. However, semi-conducting quality films have been produced. Further testing is required.

  8. A review of mathematical modelling of the zinc/bromine flow cell and stack of cells

    NASA Astrophysics Data System (ADS)

    Evans, T. I.; White, R. E.

    Macroscopic mathematical models for investigating various aspects of the zinc/bromine cell and stack of cells are reviewed. The general material balance equation for each species, in addition to the general expressions describing both transport in a parallel plate electrochemical reactor and the electrode kinetics, are first given. Partial differential equation models predicting current and potential distributions, an algebraic model including shunt currents and associated energy losses, and ordinary differential equation models predicting energy efficiency of the cell as a function of the state-of-charge are discussed. Microscopic models which describe the initiation and subsequent growth of zinc dendrites are also considered.

  9. Chlorophyll-sensitized solar cells

    SciTech Connect

    Glenn, D.F.

    1984-01-01

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

  10. Photon upconversion for thin film solar cells

    Microsoft Academic Search

    J. de Wild

    2012-01-01

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

  11. Photon management in thin film solar cells

    Microsoft Academic Search

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

    2009-01-01

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

  12. 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. [Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2 (Canada); Mar, Arthur, E-mail: arthur.mar@ualberta.c [Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2 (Canada)

    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

  13. Zinc Supplementation and Somatic Cell Count in Milk of Dairy Cows

    Microsoft Academic Search

    A. Pechová; L. Pavlata; E. Lokajová

    2006-01-01

    Pechová A., L. Pavlata, E. Lokajová: Zinc Supplementation and Somatic Cell Count in Milk of Dairy Cows. Acta Vet Brno 2006, 75: 355-361. The goal of the study was to test the possibility of raising milk zinc (Zn) concentration by increasing the supplementation of Zn, and to assess the effect on the somatic cell count. The experiment was performed at

  14. ITO/InP solar cells: A comparison of devices fabricated by ion beam and RF sputtering of the ITO

    NASA Technical Reports Server (NTRS)

    Coutts, T. J.

    1987-01-01

    This work was performed with the view of elucidating the behavior of indium tin oxide/indium phosphide (ITO/InP) solar cells prepared by RF and ion beam sputtering. It was found that using RF sputter deposition of the ITO always leads to more efficient devices than ion beam sputter deposition. An important aspect of the former technique is the exposure of the single crystal p-InP substrates to a very low plasma power prior to deposition. Substrates treated in this manner have also been used for ion beam deposition of ITO. In this case the cells behave very similarly to the RF deposited cells, thus suggesting that the lower power plasma exposure (LPPE) is the crucial process step.

  15. Nanosized Zinc Oxide Induces Toxicity in Human Lung Cells

    PubMed Central

    Sahu, Devashri; Kannan, G. M.; Vijayaraghavan, R.; Anand, T.; Khanum, Farhath

    2013-01-01

    Zinc oxide nanoparticles (ZnO-NPs) are increasingly used in sunscreens, biosensors, food additives, pigments, rubber manufacture, and electronic materials. With the wide application of ZnO-NPs, concern has been raised about its unintentional health and environmental impacts. This study investigates the toxic effects of ZnO-NPs in human lung cells. In order to assess toxicity, human lung epithelial cells (L-132) were exposed to dispersion of 50?nm ZnO-NPs at concentrations of 5, 25, 50, and 100??g/mL for 24?h. The toxicity was evaluated by observing changes in cell morphology, cell viability, oxidative stress parameters, DNA damage analysis, and gene expression. Exposure to 50?nm ZnO-NPs at concentrations between 5 and 100??g/mL decreased cell viability in a concentration-dependent manner. Morphological examination revealed cell shrinkage, nuclear condensation, and formation of apoptotic bodies. The oxidative stress parameters revealed significant depletion of GSH level and increase in ROS levels suggesting generation of oxidative stress. ZnO-NPs exposure caused DNA fragmentation demonstrating apoptotic type of cell death. ZnO-NPs increased the expression of metallothionein gene, which is considered as a biomarker in metal-induced toxicity. To summarize, ZnO-NPs cause toxicity in human lung cells possibly through oxidative stress-induced apoptosis. PMID:23997968

  16. Zinc and insulin in pancreatic beta-cells.

    PubMed

    Li, Yang V

    2014-03-01

    Zinc (Zn2+) is an essential element crucial for growth and development, and also plays a role in cell signaling for cellular processes like cell division and apoptosis. In the mammalian pancreas, Zn2+ is essential for the correct processing, storage, secretion, and action of insulin in beta (?)-cells. Insulin is stored inside secretory vesicles or granules, where two Zn2+ ions coordinate six insulin monomers to form the hexameric-structure on which maturated insulin crystals are based. The total Zn2+ content of the mammalian pancreas is among the highest in the body, and Zn2+ concentration reach millimolar levels in the interior of the dense-core granule. Changes in Zn2+ levels in the pancreas have been found to be associated with diabetes. Hence, the relationship between co-stored Zn2+ and insulin undoubtedly is critical to normal ?-cell function. The advances in the field of Zn2+ biology over the last decade have facilitated our understanding of Zn2+ trafficking, its intracellular distribution and its storage. When exocytosis of insulin occurs, insulin granules fuse with the ?-cell plasma membrane and release their contents, i.e., insulin as well as substantial amount of free Zn2+, into the extracellular space and the local circulation. Studies increasingly indicate that secreted Zn2+ has autocrine or paracrine signaling in ?-cells or the neighboring cells. This review discusses the Zn2+ homeostasis in ?-cells with emphasis on the potential signaling role of Zn2+ to islet biology. PMID:23979673

  17. 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.

  18. 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.

  19. 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

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

    Microsoft Academic Search

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

    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

  1. Dye-sensitized solar cells

    Microsoft Academic Search

    Michael Grätzel

    2003-01-01

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

  2. Solar cell module assembly jig

    Microsoft Academic Search

    H. W. Ofarrell

    1966-01-01

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

  3. Monolithic and mechanical multijunction space solar cells

    Microsoft Academic Search

    R. K. Jain; D. J. Flood

    1993-01-01

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

  4. Electron and proton damage coefficients for heteroepitaxial InP solar cells

    SciTech Connect

    Jain, R.K.; Weinberg, I.; Brinker, D.J.; Swartz, C.K. [National Aeronautics and Space Administration, Cleveland, OH (United States). Lewis Research Center; Scheiman, D.A. [NYMA, Inc., Brookpark, OH (United States); Vargas-Aburto, C. [Kent State Univ., OH (United States)

    1994-12-31

    Indium phosphide solar cells are known to be significantly more radiation resistance than either gallium arsenide or silicon. Their growth by heteroepitaxy offers additional advantages over growth by homoepitaxy. InP cells have been grown on lower cost substrates and if heteroepitaxial cells are to be used in space, their behavior under electron and proton irradiations has to be understood. This work presents the new calculated results for 1 MeV electron and 0.2 to 10 MeV proton irradiations on the performance of the n{sup +}p heteroepitaxial InP cells. The heteroepitaxial InP solar cell efficiency degradation has been explained by the decrease in the base diffusion length. The effect of carrier removal has been considered in the calculations. The electron and proton diffusion length damage coefficient, K{sub L} has been calculated as a function of fluence. The proton damage coefficient remains almost constant with fluence for 0.5, 3, and 10 MeV energies, but increases for the 0.2 MeV. The 1 MeV electron damage coefficient decreases with fluence. These results suggest that the electron and proton damage mechanisms are different.

  5. Silicon solar cells: Physical metallurgy principles

    Microsoft Academic Search

    Michael G. Mauk

    2003-01-01

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

  6. Detailed balance analysis of nanophotonic solar cells

    E-print Network

    Fan, Shanhui

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

  7. 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

  8. EE580 Solar Cells Todd J. Kaiser

    E-print Network

    Kaiser, Todd J.

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

  9. EE580 Solar Cells Todd J. Kaiser

    E-print Network

    Kaiser, Todd J.

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

  10. 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

  11. EE580 Solar Cells Todd J. Kaiser

    E-print Network

    Kaiser, Todd J.

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

  12. Texturisation of single crystalline silicon solar cell

    Microsoft Academic Search

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

    2010-01-01

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

  13. Qualification of European nonreflective solar cells

    Microsoft Academic Search

    J. C. Larue

    1978-01-01

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

  14. Solar cell array design handbook. Volume I

    Microsoft Academic Search

    Rauschenbach

    1976-01-01

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

  15. Solar Cell Crack Inspection by Image Processing

    Microsoft Academic Search

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

    2009-01-01

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

  16. Solar cell crack inspection by image processing

    Microsoft Academic Search

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

    2004-01-01

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

  17. Predicted solar cell edge radiation effects

    Microsoft Academic Search

    Markland T. Gates

    1993-01-01

    The Advanced Solar Cell Orbital Test (ASCOT) will test six types of solar cells in a high energy proton environment. During the design of the experiment a question was raised about the effects of proton radiation incident on the edge of the solar cells and whether edge radiation shielding was required. Historical geosynchronous data indicated that edge radiation damage is

  18. Calculated performance of p(+)n InP solar cells with In(0.52)Al(0.48)As window layers

    NASA Astrophysics Data System (ADS)

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

    1991-11-01

    The performance of indium phosphide solar cells with lattice matched wide band-gap In(0.52)Al(0.48)As window layers was calculated using the PC-1D computer code. The conversion efficiency of p(+)n InP solar cells is improved significantly by the window layer. No improvement is seen for n(+)p structures. The improvement in InP cell efficiency was studied as a function of In(0.52)Al(0.48)As layer thickness. The use of the window layer improves both the open circuit voltage and short circuit current.For a typical In(0.52)Al(0.48)As window layer thickness of 20 nm, the cell efficiency improves in excess of 27 percent to a value of 18.74 percent.

  19. 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;...

  20. Ni2Pa promising candidate for back contacts to CdS\\/CdTe solar cells

    Microsoft Academic Search

    V. Viswanathan; B. Tetali; P. Selvaraj; S. Jagannathan; D. L. Morel; C. S. Ferekides; S. Asher

    2000-01-01

    An important device issue that must be addressed for the use of CdTe solar cells in terrestrial applications is the formation of an effective and reliable back contact. Most successful efforts to date have been relying on the use of copper either in elemental form or in conjunction with other materials. Two examples are copper doped zinc telluride and copper

  1. Flexibility in space solar cell production

    NASA Technical Reports Server (NTRS)

    Khemthong, Scott; Iles, Peter A.

    1989-01-01

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

  2. Polyphenol-rich beverages enhance zinc uptake and metallothionein expression in Caco-2 cells.

    PubMed

    Sreenivasulu, Kilari; Raghu, Pullakhandam; Nair, K Madhavan

    2010-05-01

    The effect of red wine (RW), red grape juice (RGJ), green tea (GT), and representative polyphenols on Caco-2 cell (65)Zn uptake was explored. RW, RGJ, and GT enhanced the uptake of zinc from rice matrix. Fractionation of RW revealed that enhancing activity of zinc uptake was exclusively resided in the polyphenol fraction. Among the polyphenols tested, only tannic acid and quercitin stimulated the uptake of zinc while others did not influence the uptake. In tune with these results, only tannic acid and quercitin competed with zinquin (a zinc selective fluorophore) for zinc in vitro. Although all the polyphenols tested appear to enhance the expression of metallothionein (MT), the induction was higher with tannic acid, quercitin, and RW extract. Furthermore, phytic acid abrogated the tannic acid-induced MT expression. These results suggest that polyphenol-rich beverages, tannic acid, and quercitin bind and stimulate the zinc uptake and MT expression in Caco-2 cells. PMID:20546406

  3. 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.

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

    E-print Network

    Chen, Junhong

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

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

    Microsoft Academic Search

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

    2009-01-01

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

  6. Mixed ternary heterojunction solar cell

    SciTech Connect

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

    1992-08-25

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

  7. 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

  8. Biological solar cell

    NASA Astrophysics Data System (ADS)

    Seibert, M.; Janzen, A. F.

    1980-04-01

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

  9. Towards stable silicon nanoarray hybrid solar cells

    NASA Astrophysics Data System (ADS)

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

    2014-01-01

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

  10. 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.

  11. 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

  12. Colchicine induced intraneuronal free zinc accumulation and dentate granule cell degeneration.

    PubMed

    Choi, Bo Young; Lee, Bo Eun; Kim, Jin Hee; Kim, Hyun Jung; Sohn, Min; Song, Hong Ki; Chung, Tae Nyoung; Suh, Sang Won

    2014-08-01

    Colchicine has been discovered to inhibit many inflammatory processes such as gout, familial Mediterranean fever, pericarditis and Behcet disease. Other than these beneficial anti-inflammatory effects, colchicine blocks microtubule-assisted axonal transport, which results in the selective loss of dentate granule cells of the hippocampus. The mechanism of the colchicine-induced dentate granule cell death and depletion of mossy fiber terminals still remains unclear. In the present study, we hypothesized that colchicine-induced dentate granule cell death may be caused by accumulation of labile intracellular zinc. 10 ?g kg(-1) of colchicine was injected into the adult rat hippocampus and then brain sections were evaluated at 1 day or 1 week later. Neuronal cell death was evaluated by H&E staining or Fluoro-Jade B. Zinc accumulation and vesicular zinc were detected by N-(6-methoxy-8-quinolyl)-para-toluene sulfonamide (TSQ) staining. To test whether an extracellular zinc chelator can prevent this process, CaEDTA was injected into the hippocampus over a 5 min period with colchicine. To test whether other microtubule toxins also produce similar effects as colchicine, vincristine was injected into the hippocampus. The present study found that colchicine injection induced intracellular zinc accumulation in the dentate granule cells and depleted vesicular zinc from mossy fiber terminals. Injection of a zinc chelator, CaEDTA, did not block the zinc accumulation and neuronal death. Vincristine also produced intracellular zinc accumulation and neuronal death. These results suggest that colchicine-induced dentate granule cell death is caused by blocking axonal zinc flow and accumulation of intracellular labile zinc. PMID:24874779

  13. 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.

  14. Degradation mechanism of ZnO-based dye-sensitized solar cells

    Microsoft Academic Search

    Lin Ke; Surani Bin Dolmanan; Lu Shen; Pramoda Kumari Pallathadk; Zheng Zhang; Doreen Mei Ying Lai; Hong Liu

    2010-01-01

    Zinc oxide (ZnO)-based dye-sensitized solar cell was fabricated and tested under constant solar simulator illumination until the photocurrent decreased. Electrolyte and dye were studied by Fourier transform infrared and UV–vis absorption spectroscopy. Scanning electron microscopy, photoluminescence and X-ray photoelectron spectroscopy were used to study the degradation of ZnO. Secondary Ion Mass spectroscopy was used to analyze the structural change of

  15. I-III-VI.sub.2 based solar cell utilizing the structure CuInGaSe.sub.2 CdZnS\\/ZnO

    Microsoft Academic Search

    Wen S. Chen; John M. Stewart

    1992-01-01

    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

  16. 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

  17. 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.

  18. Biological solar cells

    NASA Astrophysics Data System (ADS)

    Seibert, M.; Janzen, A. F.

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

  19. Dye-Sensitized Solar Cells

    NSDL National Science Digital Library

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

  20. in thin film solar cells

    Microsoft Academic Search

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

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

  1. 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.

  2. 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 ...

  3. Temperature Dependence of Protocrystalline Silicon\\/Microcrystalline Silicon Double-Junction Solar Cells

    Microsoft Academic Search

    Kobsak Sriprapha; Seung Yeop Myong; Akira Yamada; Makoto Konagai

    2008-01-01

    We have investigated the temperature dependence of hydrogenated protocrystalline silicon (pc-Si:H)\\/hydrogenated microcrystalline silicon (muc-Si:H) double-junction solar cells. A boron-doped zinc oxide (ZnO:B) film is employed as an intermediate layer between the pc-Si:H top cell and the muc-Si:H bottom cell. The fabricated solar cells exhibit good stability against light soaking. Photocurrent density-voltage (photo J-V) characteristics are measured under AM 1.5 illumination

  4. Three-junction solar cell

    DOEpatents

    Ludowise, Michael J. (Cupertino, CA)

    1986-01-01

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

  5. Multi-junction solar cell device

    Microsoft Academic Search

    Daniel J. Friedman; John F. Geisz

    2007-01-01

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

  6. Current-Enhanced Quantum Well Solar Cells

    Microsoft Academic Search

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

    2006-01-01

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

  7. 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. [Harvard Univ., Cambridge, MA (United States)

    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.

  8. heat treatment for solar cells

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  9. 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.

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

    Microsoft Academic Search

    Komal Magsi; Emilia Macdonald; Leon Shterengas

    2010-01-01

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

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

    SciTech Connect

    Solozhenko, Vladimir L. [LSPM–CNRS, Université Paris Nord, 93430 Villetaneuse (France); Kurakevych, Oleksandr O.; Le Godec, Yann [IMPMC, UPMC Sorbonne Universités, UMR CNRS 7590, Muséum National d'Histoire Naturelle, IRD UMR 206, 75005 Paris (France); Kurnosov, Aleksandr V. [Bayerisches Geoinstitut, Universität Bayreuth, 95440 Bayreuth (Germany); Oganov, Artem R. [Department of Geosciences, Center for Materials by Design, Institute for Advanced Computational Science, Stony Brook University, Stony Brook, New York 11794-2100 (United States)

    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.

  12. Energy Conversion: Nano Solar Cell

    NASA Astrophysics Data System (ADS)

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

    2009-09-01

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

  13. Zinc deficiency impairs neuronal precursor cell proliferation and induces apoptosis via p53-mediated mechanisms.

    PubMed

    Corniola, Rikki S; Tassabehji, Nadine M; Hare, Joan; Sharma, Girdhari; Levenson, Cathy W

    2008-10-27

    The potential importance of stem cells in the adult central nervous system (CNS) that cannot only divide, but also participate in neurogenesis, is now widely appreciated. While we know that the trace element zinc is needed for brain development, the role of this essential nutrient in adult stem cell proliferation and neurogenesis has not been investigated. Adult male rats fed a zinc-restricted diet had approximately 50% fewer Ki67-positive stem cells in the subgranular zone (SGZ) and granular cell layer of the dentate gyrus compared to both zinc-adequate and pair-fed controls (p<0.05). Zinc-deficient rats also had a significant increase the number of TUNEL-labeled cells in the SGZ compared to pair-fed rats (p<0.05). To explore the mechanisms responsible for the effects of zinc deficiency, cultured human Ntera-2 (NT2) neuronal precursor cells were deprived of zinc using the chelator N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN). Consistent with the effects of deficiency in vivo, TPEN treatment resulted in a significant decrease in cellular proliferation, as measured by bromodeoxyuridine (BrdU) uptake, and an increase in caspase3/7-dependent apoptosis. These changes were accompanied by increases in nuclear p53. Oligonucleotide arrays, coupled with use of a dominant-negative p53 construct in NT2 cells, identified 14 differentially regulated p53 target genes. In the early phases zinc deficiency, p53 targets responsible for cell cycle arrest were induced. Continuation of deficiency resulted in the induction of a variety of pro-apoptotic genes such as transforming growth factor-beta (TGF-beta) and retinoblastoma-1 (Rb-1), as well as cellular protection genes such as glutathione peroxidase (GPx). These data suggest that zinc plays a role in neurogenesis by regulating p53-dependent molecular mechanisms that control neuronal precursor cell proliferation and survival. PMID:18778698

  14. 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

  15. A Surface-Controlled Solar Cell

    NASA Technical Reports Server (NTRS)

    Daud, T.; Crotty, G. T.

    1987-01-01

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

  16. 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.

  17. Ultrasonic Bonding of Solar-Cell Leads

    NASA Technical Reports Server (NTRS)

    Frasch, W.

    1984-01-01

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

  18. 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.

  19. Zinc transferrin stimulates red blood cell formation in the head kidney of common carp (Cyprinus carpio).

    PubMed

    Chen, Yen-Hua; Fang, Szu-Wei; Jeng, Sen-Shyong

    2013-09-01

    The common carp is one of the few fish able to tolerate extremely low oxygen levels. These fish store zinc in their digestive tract tissue and head kidney at concentrations of 300-500?g/g of fresh tissue, which is 5-10 times higher than in other fish. Previous studies have indicated a link between the high zinc levels in the common carp and stress erythropoiesis. In this report, using suspension-cultured common carp head kidney cells with or without ZnCl2 supplementation, we found that zinc stimulated the proliferation of immature red blood cells; however, this effect was only observed when the culture was supplemented with carp serum. We identified the active component of carp serum to be transferrin. The zinc-transferrin complex interacts with the transferrin receptor and stimulates the proliferation of immature red blood cells. In addition, the growth rate of the immature red blood cells was regulated by the supplied ZnCl2 concentration. Under stress, the zinc in the common carp digestive tract tissue was released and used as a signal to induce red blood cell formation in the head kidney. This cell culture system might provide a means for exploring the regulatory role of zinc in hematopoietic cell growth. PMID:23665074

  20. Novel heterojunction solar cells with conversion efficiencies approaching 21% on p-type crystalline silicon substrates

    Microsoft Academic Search

    Bahman Hekmatshoar; Davood Shahrjerdi; Devendra K. Sadana

    2011-01-01

    We report novel high-efficiency heterojunction (HJ) solar cells with Engineered Low-bandgap Interlayer and Thin Epitaxial emitter (ELITE) structure, achieving a record conversion efficiency of 20.7% on p-type crystalline Si (c-Si) substrates. Cell fabrication is based on plasma-enhanced chemical vapor deposition (PECVD) of contact layers at temperatures below 200°C and room-temperature sputtering of low-cost Al-doped zinc-oxide (ZnO:Al) electrodes.

  1. 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.

  2. 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.

  3. 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

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

    Microsoft Academic Search

    Chunfu Zhang; Hailong You; Zhenhua Lin; Yue Hao

    2011-01-01

    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.

  5. 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.

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

    Microsoft Academic Search

    Thomas Kirchartz; Julian Mattheis; Uwe Rau

    2008-01-01

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

  7. 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.

  8. Multi-junction solar cells based on the integration of II\\/VI and III\\/V semiconductors

    Microsoft Academic Search

    D. Ding; S.-N. Wu; S. Wang; S. R. Johnson; S.-Q. Yu; X. Liu; J. K. Furdyna; Y.-H. Zhang

    2008-01-01

    High-efficiency multifunction solar cells are attracting a great deal of attention for both space and terrestrial applications. We proposed the monolithic integration of the II\\/VI (ZnCdMg)(SeTe) and the III\\/V (InAlGa)(AsSb) material systems for multijunction solar cells. These material systems have direct bandgap, zinc blende, quaternary alloys, lattice-matched to GaSb substrates that cover the entire optical spectrum from greater than 3.0

  9. The influence of substrate heating on morphology and layer growth in C 60:ZnPc bulk heterojunction solar cells

    Microsoft Academic Search

    Steffen Pfuetzner; Christine Mickel; Jens Jankowski; Moritz Hein; Jan Meiss; Christoph Schuenemann; Chris Elschner; Alexandr A. Levin; Bernd Rellinghaus; Karl Leo; Moritz Riede

    2011-01-01

    The change of morphology in mixed layers due to different substrate temperature Tsub of organic solar cells containing C60 and zinc phthalocyanine (ZnPc) is studied. Heating the substrate during deposition of the bulk heterojunction C60:ZnPc leads to a significant improvement of solar cell performance, mainly due to an increase in photocurrent and fill factor (FF). This is attributed to improved

  10. ZnO thin films fabricated by chemical bath deposition, used as buffer layer in organic solar cells

    Microsoft Academic Search

    Y. Lare; A. Godoy; L. Cattin; K. Jondo; T. Abachi; F. R. Diaz; M. Morsli; K. Napo; M. A. del Valle; J. C. Bernède

    2009-01-01

    ZnO thin films synthetized by chemical bath deposition are used as buffer layer between the anode and the organic electron donor in organic solar cells. Films deposited from zinc nitrate solutions are annealed in room air at 300°C for half an hour. The X-ray diffraction and microanalysis studies show that ZnO polycrystalline thin films are obtained. The solar cells used

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

    NASA Technical Reports Server (NTRS)

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

    1971-01-01

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

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

    Microsoft Academic Search

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

    2011-01-01

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

  13. Indium Phosphide Planar Integrated Optics Comes of Age Jens Noeckel

    E-print Network

    Nöckelm, Jens

    Indium Phosphide Planar Integrated Optics Comes of Age Jens Noeckel Tom Pierson Jane Zucker exceeds supply. Indium Phosphide: Adapting Form to Function PLCs can serve many roles in fiberoptic of the spectrum, the current material of choice is indium phosphide. When compared with the sophistication

  14. Ultrathin silicon solar cell for space application

    NASA Astrophysics Data System (ADS)

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

    1982-01-01

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

  15. 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

  16. Effect of the interface morphology on the fill factor of plastic solar cells

    Microsoft Academic Search

    V. Djara; J. C. Bernède

    2005-01-01

    Organic bilayer solar cells based on a donor\\/acceptor junction of zinc-phthalocyanine\\/1,4-diaminoanthraquinone (ZnPc\\/1,4-DAAQ) were studied. The transparent conductive oxide (TCO) electrode used was either the indium tin oxide (ITO) or the zinc oxide (ZnO), also the (poly(3,4-ethylenedioxythiophene):poly(styrene sulfonic acid (PEDOT:PSS) was used as conductive polymer. Two different configurations were prepared: glass\\/ITO (or ZnO)\\/ZnPc\\/1,4-DAAQ\\/Al configuration and glass\\/Al\\/1,4-DAAQ\\/ZnPc\\/PEDOT:PSS\\/ ITO (or ZnO)\\/glass configuration. From

  17. Chemical bath deposited (CBD)ZnO buffer layer for CIGS solar cells

    Microsoft Academic Search

    R. Mikami; H. Miyazaki; T. Abe; A. Yamada; M. Konagai

    2003-01-01

    Zinc oxide was grown by a chemical bath deposition (CBD) method and it was applied to a buffer layer for Cu(InGa)Se\\/sub 2\\/ solar cells. The film was deposited with a solution of zinc acetate (Zn(CH\\/sub 3\\/COO)) and ethylenediamine (NH\\/sub 2\\/CH\\/sub 2\\/CH\\/sub 2\\/NH\\/sub 2\\/) or ammonia (NH\\/sub 4\\/OH). The films grown with a NH\\/sub 4\\/OH-base solution showed good morphology and adhesion

  18. Flexible solid-state dye solar cells

    Microsoft Academic Search

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

    2002-01-01

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

  19. Bonder for Solar-Cell Strings

    NASA Technical Reports Server (NTRS)

    Garwood, G.; Frasch, W.

    1982-01-01

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

  20. Regeneration of T-cell helper function in zinc-deficient adult mice

    PubMed Central

    Fraker, Pamela J.; DePasquale-Jardieu, Paula; Zwickl, Craig M.; Luecke, Richard W.

    1978-01-01

    Diets deficient in zinc cause rapid atrophy of the thymus and loss of T-cell helper function in the young adult A/J mouse. Because zinc deficiency, as well as other nutritional deficiences, causes extensive damage to the immune system, the question arose as to whether zinc-deficient mice could repair the thymus and fully regenerate T-cell helper function if returned to diets containing adequate amounts of zinc. Five-week-old A/J female mice were fed either a zinc-deficient (<1 ?g of Zn per g) or a zinc-adequate (50 ?g of Zn per g) diet for 31 days. Histological examination of thymuses from the zinc-deficient mice revealed that the cortex was preferentially involuted and the thymus was about one-third of normal size. The direct plaque-forming cells produced per mouse spleen in response to immunization with sheep erythrocytes was 34% of normal; indirect plaque-forming cells were 18% of normal (Jerne plaque assay). After the deficient mice had been fed a zinc-adequate diet for 1 week, their response was nearly normal, except that the indirect response was 68% of controls; in this same period, the thymuses of these mice had quadrupled in size and exhibited a greatly enlarged cortex repopulated with immature thymocytes. By 2 weeks, the thymuses of the previously zinc-deficient mice were normal in size and appearance; however, there was a slight increases in numbers of indirect plaque-forming cells. By 4 weeks, the thymus weights, direct and indirect plaque-forming cell counts, and secondary response of the previously deficient mice were normal. Mice that were nearly athymic after 45 days of dietary zinc deficiency were also able to fully reconstruct the thymus and regenerate T-cell helper function. The data show that the zinc-deficient young adult mouse has the capacity to fully restore the T-cell-dependent antibody-mediated responses upon nutritional repletion. Images PMID:310122

  1. 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

  2. Nanoparticle Solar Cell Final Technical Report

    Microsoft Academic Search

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

    2008-01-01

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

  3. 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

  4. Effects of contamination on solar cell coverglass

    Microsoft Academic Search

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

    2010-01-01

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

  5. Stability\\/degradation of polymer solar cells

    Microsoft Academic Search

    Mikkel Jørgensen; Kion Norrman; Frederik C. Krebs

    2008-01-01

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

  6. Report on high intensity solar cells

    SciTech Connect

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

    1985-02-01

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

  7. Method of manufacture of solar cell panel

    Microsoft Academic Search

    J. S. Walker; W. C. Kittler

    1978-01-01

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

  8. Porous silicon in solar cells technology

    Microsoft Academic Search

    T. V. Semikina; A. N. Shmyryeva

    1998-01-01

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

  9. A Simplified Solar Cell Array Modelling Program

    Microsoft Academic Search

    R. D. Hughes

    1982-01-01

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

  10. Modeling and simulation of organic solar cells

    Microsoft Academic Search

    Liming Liu; Guangyong Li

    2010-01-01

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

  11. Thin solar cell and lightweight array

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

  12. Black and thin silicon solar cells

    Microsoft Academic Search

    J. Michel

    1976-01-01

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

  13. Improved radiation hardness of silicon solar cells

    Microsoft Academic Search

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

    2000-01-01

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

  14. Introduction to basic solar cell measurements

    NASA Technical Reports Server (NTRS)

    Brandhorst, H. W., Jr.

    1976-01-01

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

  15. 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

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

    NASA Astrophysics Data System (ADS)

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

    1984-03-01

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

  17. Zinc pyrithione induces cellular stress signaling and apoptosis in Hep2 cervical tumor cells: the role of mitochondria and lysosomes

    Microsoft Academic Search

    Emil Rudolf; Miroslav ?ervinka

    2010-01-01

    Increased intracellular free zinc concentrations are associated with activation of several stress signaling pathways, specific\\u000a organelle injury and final cell death. In the present work we examined the involvement of mitochondria and lysosomes and their\\u000a crosstalk in free zinc-induced cell demise. We report that treatment of cervical tumor Hep-2 cells with zinc pyrithione leads\\u000a to an early appearance of cytoplasmic

  18. High-Temperature Solar Cell Development

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

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

  19. Coating Processes Boost Performance of Solar Cells

    NASA Technical Reports Server (NTRS)

    2012-01-01

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

  20. Improved conversion efficiency of amorphous Si solar cells using a mesoporous ZnO pattern

    NASA Astrophysics Data System (ADS)

    Go, Bit-Na; Kim, Yang Doo; suk Oh, Kyoung; Kim, Chaehyun; Choi, Hak-Jong; Lee, Heon

    2014-09-01

    To provide a front transparent electrode for use in highly efficient hydrogenated amorphous silicon (a-Si:H) thin-film solar cells, porous flat layer and micro-patterns of zinc oxide (ZnO) nanoparticle (NP) layers were prepared through ultraviolet nanoimprint lithography (UV-NIL) and deposited on Al-doped ZnO (AZO) layers. Through this, it was found that a porous micro-pattern of ZnO NPs dispersed in resin can optimize the light-trapping pattern, with the efficiency of solar cells based on patterned or flat mesoporous ZnO layers increased by 27% and 12%, respectively.

  1. Improved conversion efficiency of amorphous Si solar cells using a mesoporous ZnO pattern.

    PubMed

    Go, Bit-Na; Kim, Yang Doo; Suk Oh, Kyoung; Kim, Chaehyun; Choi, Hak-Jong; Lee, Heon

    2014-01-01

    To provide a front transparent electrode for use in highly efficient hydrogenated amorphous silicon (a-Si:H) thin-film solar cells, porous flat layer and micro-patterns of zinc oxide (ZnO) nanoparticle (NP) layers were prepared through ultraviolet nanoimprint lithography (UV-NIL) and deposited on Al-doped ZnO (AZO) layers. Through this, it was found that a porous micro-pattern of ZnO NPs dispersed in resin can optimize the light-trapping pattern, with the efficiency of solar cells based on patterned or flat mesoporous ZnO layers increased by 27% and 12%, respectively. PMID:25276101

  2. Silicon film solar cell process

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

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

  3. Phosphide poisoning: a review of literature.

    PubMed

    Bumbrah, Gurvinder Singh; Krishan, Kewal; Kanchan, Tanuj; Sharma, Madhulika; Sodhi, Gurvinder Singh

    2012-01-10

    Metal phosphides in general and aluminium phosphide in particular are potent insecticides and rodenticides. These are commercially used for protection of crops during storage, as well as during transportation. However, these are highly toxic substances. Their detrimental effects may range from nausea and headache to renal failure and death. It is, therefore, pertinent to ensure their circumspect handling to avoid poisoning episodes. Its poisoning has a high mortality and recent years have seen an increase in the number of poisoning cases and deaths caused by suicidal ingestion. Yet due to their broad spectrum applications, these chemicals cannot be written off. The present communication reviews the various aspects of toxicity associated with metal phosphides. PMID:21763089

  4. The chemical cell biology of zinc: structure and intracellular fluorescence of a zinc-quinolinesulfonamide complex

    Microsoft Academic Search

    M. Sarwar Nasir; Christoph J. Fahrni; David A. Suhy; Kevin J. Kolodsick; Christopher P. Singer; Thomas V. O'Halloran

    1999-01-01

    p  -toluenesulfonamido-quinoline, TSQ, are potentially powerful probes of intracellular zinc chemistry; however, the structure,\\u000a thermodynamics, and stoichiometry of the metal complexes, and the molecular basis of Zn(II) recognition, remain open issues.\\u000a To address these, we report the first structural characterization of a Zn(II) complex of a TSQ derivative, namely 2-methyl-6-methoxy-8-p-toluenesulfonamido-quinoline (3) and describe its unusual coordination chemistry. The crystal structure of

  5. Indium phosphide/cadmium sulfide thin-film solar cells. Quarterly technical progress report No. 3, December 1979-April 1980

    SciTech Connect

    Zanio, K.

    1980-06-01

    Thin films (approx. 1 ..mu..m thick) and large grains (approx. 40 x 40 ..mu..m) of InP were epitaxially deposited on low-cost recrystallized CdS (RXCdS) substrates at 280/sup 0/C by planar reactive deposition. At 380/sup 0/C, a 0.4- to 1.0-..mu..m-thick In-Cd-S transition layer between the InP and the RXCdS degrades the quality of the InP epitaxy. However, p-type InP films were prepared at this temperature by Be-doping and capping the entire RXCdS substrate with InP. Large grains of CdTe (approx. 40 ..mu..m) were also deposited on RXCdS substrates at 460/sup 0/C by physical vapor deposition. The grain size of the RXCdS is typically 40 ..mu..m. However, during this period we prepared RXCdS with grains having dimensions up to 300 ..mu..m.

  6. 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...

  7. Isoelectronic Traps in Gallium Phosphide

    NASA Astrophysics Data System (ADS)

    Christian, Theresa; Alberi, Kirstin; Beaton, Daniel; Fluegel, Brian; Mascarenhas, Angelo

    2015-03-01

    Isoelectronic substitutional dopants can result in strongly localized exciton traps within a host bandstructure such as gallium arsenide (GaAs) or gallium phosphide (GaP). These traps have received great attention for their role in the anomalous bandgap bowing of nitrogen or bismuth-doped GaAs, creating the dramatic bandgap tunability of these unusual dilute alloys. In the wider, indirect-bandgap host material GaP, these same isoelectronic dopants create bound states within the gap that can have very high radiative efficiency and a wealth of discrete spectral transitions illuminating the symmetry of the localized excitonic trap state. We will present a comparative study of nitrogen and bismuth isoelectronic traps in GaP. Research was supported by the U. S. Department of Energy, Basic Energy Sciences, Materials Sciences and Engineering Division under contract DE-AC36-08GO28308 and by the Department of Energy Office of Science Graduate Fellowship Program (DOE SCGF), made possible in part by the American Recovery and Reinvestment Act of 2009, administered by ORISE-ORAU under contract no. DE-AC05-06OR23100.

  8. 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

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

    SciTech Connect

    Rousselet, Estelle [CEA, DSV, IRTSV, Laboratoire de Chimie et Biologie des Metaux, Grenoble (France)]|[LCBM, CNRS UMR5249, Grenoble (France); Universite Joseph Fourier, Grenoble (France); Richaud, Pierre [CEA, DSV, IBEB, SBVME, LB3M, Saint-Paul-lez-Durance (France)]|[LB3M, CNRS UMR 6191, Saint-Paul-lez-Durance (France)]|[Universite Aix-Marseille (France); Douki, Thierry; Chantegrel, Jocelyne Garcia; Favier, Alain [Universite Joseph Fourier, Grenoble (France)]|[CEA, DSM, INaC/SCIB, Laboratoire 'Lesions des Acides Nucleiques', Grenoble (France); Bouron, Alexandre [CEA, DSV, IRTSV, Laboratoire de Chimie et Biologie des Metaux, Grenoble (France)]|[LCBM, CNRS UMR5249, Grenoble (France)]|[Universite Joseph Fourier, Grenoble (France); Moulis, Jean-Marc [CEA, DSV, IRTSV, Laboratoire de Chimie et Biologie des Metaux, Grenoble (France)]|[LCBM, CNRS UMR5249, Grenoble (France)]|[Universite Joseph Fourier, Grenoble (France)], E-mail: jean-marc.moulis@cea.fr

    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.

  10. 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

  11. Development and fabrication of sealed silver-zinc cells, phase 1

    NASA Technical Reports Server (NTRS)

    Blake, I. C.; Donnel, C. P., III

    1973-01-01

    A facility was designed, constructed and equipped for the production of prismatic alkaline rechargeable battery cells using inorganic (ceramic) separators. This unique facility is environmentally controlled and contains separate areas for electrode fabrication, separator processing, cell assembly, cell finishing and testing. An initial production run of 125 sealed silver zinc cells, using inorganic separators, was made in the facility in order to provide samples for baseline performance tests. Ten of these cells were given performance characterization and life cycle tests.

  12. Improving Solar Cells With Polycrystalline Silicon

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

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

  13. High performance porous silicon solar cell development

    Microsoft Academic Search

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

    1994-01-01

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

  14. Single-nanowire Si solar cells

    Microsoft Academic Search

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

    2008-01-01

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

  15. Recovery of Metal Values from Spent Zinc-Carbon Dry Cell Batteries

    NASA Astrophysics Data System (ADS)

    Khan, Majharul Haque; Gulshan, Fahmida; Kurny, A. S. W.

    2013-04-01

    Spent zinc-carbon dry cell batteries were characterized in the process of recovery of metal values. Zinc, manganese and steel were the major metallic materials constituting 63 % of the weight of spent batteries. Different components of the spent batteries were separately processed to extract the metallic values. A maximum of 92 % of total amount of zinc contained in the anodes could be extracted with a purity of over 99.0 % from the anodes by heating at 600 °C for 10 min in presence of 12 % NH4Cl flux. Spent electrolyte paste containing manganese and zinc as major metallic elements, was leached in sulfuric acid solution in presence of hydrogen peroxide as a reducing agent. The optimum condition for leaching was found to be concentration of sulfuric acid: 2.5 M, concentration of hydrogen peroxide: 10 %, temperature: 60 °C, stirring speed: 600 rpm and solid/liquid ratio 1:12. A maximum of 88 % manganese contained in the paste could be dissolved within 27 min of leaching under the optimized conditions. Dissolution of zinc under the same conditions was 97 %. A maximum of 69.89 % of manganese and 83.29 % of zinc contained in the leach liquor could be precipitated in the form of manganese carbonate and zinc oxalate.

  16. Direct glassing of silicon solar cells

    NASA Astrophysics Data System (ADS)

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

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

  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. (Biosciences Division); ( XSD)

    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. Enhancement of oxygen vacancies and solar photocatalytic activity of zinc oxide by incorporation of nonmetal

    NASA Astrophysics Data System (ADS)

    Patil, Ashokrao B.; Patil, Kashinath R.; Pardeshi, Satish K.

    2011-12-01

    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.

  19. 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

  20. Mechanism and efficiency of cell death of type II photosensitizers: effect of zinc chelation.

    PubMed

    Pavani, Christiane; Iamamoto, Yassuko; Baptista, Maurício S

    2012-01-01

    A series of meso-substituted tetra-cationic porphyrins, which have methyl and octyl substituents, was studied in order to understand the effect of zinc chelation and photosensitizer subcellular localization in the mechanism of cell death. Zinc chelation does not change the photophysical properties of the photosensitizers (all molecules studied are type II photosensitizers) but affects considerably the interaction of the porphyrins with membranes, reducing mitochondrial accumulation. The total amount of intracellular reactive species induced by treating cells with photosensitizer and light is similar for zinc-chelated and free-base porphyrins that have the same alkyl substituent. Zinc-chelated porphyrins, which are poorly accumulated in mitochondria, show higher efficiency of cell death with features of apoptosis (higher MTT response compared with trypan blue staining, specific acridine orange/ethidium bromide staining, loss of mitochondrial transmembrane potential, stronger cytochrome c release and larger sub-G1 cell population), whereas nonchelated porphyrins, which are considerably more concentrated in mitochondria, triggered mainly necrotic cell death. We hypothesized that zinc-chelation protects the photoinduced properties of the porphyrins in the mitochondrial environment. PMID:22283143

  1. 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.

  2. 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.

  3. Oxide films for solar cells obtained by the extraction pyrolytic method

    Microsoft Academic Search

    T. N. Patrusheva; A. V. Kindal’; K. A. Kalenistov; G. N. Bondarenko; S. I. Tsyganov; A. I. Khol’kin

    2009-01-01

    Oxide materials such as titanium dioxide and complex oxides of zinc, titanium, bismuth, and silicon are photoactive materials,\\u000a and therefore, it is promising to use them for solar cells manufacturing. In order to start the commercial production of oxide\\u000a film electrodes, it is necessary to develop the technology permitting the covering of large areas. In the presented work,\\u000a it is

  4. The inverted polymer solar cells using cuprous oxide as a hole transportation layer

    Microsoft Academic Search

    Ming-Yi Lin; Jen-Yu Sun; Chih-Heng Shia; Chau-Shuo Chen; Yi-An Huang; Po-Ching Yang; Yu-Min Shen; Ching-Fuh Lin

    2010-01-01

    Solution processed-metal oxide as an interlayer is introduced between the organic layer and the electrode for improving the performance of the low-cost inverted polymer solar cells. Our investigations indicate that cuprous oxide thin film as an electron blocking layer can modulate the Schottky barrier at organic\\/electrode interface and form an ohmic contact. Moreover, we also report the ridge structure zinc

  5. High transmittance and low resistive ZnO:Al films for thin film solar cells

    Microsoft Academic Search

    Jinsu Yoo; Jeonghul Lee; Seokki Kim; Kyunghoon Yoon; I. Jun Park; S. K. Dhungel; B. Karunagaran; D. Mangalaraj; Junsin Yi

    2005-01-01

    Transparent conductive oxides (TCO) are indispensable as front electrode for most of the thin film solar cells. Thin films of aluminum-doped zinc oxide (ZnO:Al), one of the promising TCOs, were prepared by radio frequency (rf) magnetron sputtering on glass (Corning 1737) substrates as a function of the deposition condition. Argon gas pressure during deposition was kept in the range 0.04–1.33

  6. 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.

  7. Thermodynamic efficiency limit of excitonic solar cells

    SciTech Connect

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

    2011-05-01

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

  8. Solar elastosis in conjunctival squamous cell neoplasm.

    PubMed

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

    2014-01-01

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

  9. 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.

  10. 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.

  11. Inkjet printing of carrier transport layers for inverted organic solar cells

    NASA Astrophysics Data System (ADS)

    Danielson, Eric; Subbaraman, Harish; Dodabalapur, Ananth

    2013-09-01

    Inverted organic solar cells, which utilize a transparent cathode and a high work function metal anode, have been the subject of extensive research. Their advantages over conventional organic solar cells include increased resistance to environmental degradation and compatibility with large area fabrication techniques. Carrier transport layers are essential for achieving high power conversion efficiencies in inverted organic solar cells and therefore need to be compatible with these large area fabrication techniques. Inkjet printing is one such technique that can be integrated into the low cost mass production of these cells via roll to roll fabrication. N-type metal oxides such as ZnO or zinc tin oxide (ZTO) have been previously used as electron transport layers for inverted cells, but only as spin coated films. We have developed inkjet printable ZTO solutions for use as electron transport layers in inverted organic solar cells, and achieve power conversion efficiencies of over 3% in inverted P3HT:PC71BM solar cells. We also discuss the effect of printing parameters on the electrical performance of these layers in inverted organic solar cells.

  12. 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...

  13. Cycles till failure of silver-zinc cells with competing failure modes - Preliminary data analysis

    Microsoft Academic Search

    S. M. Sidik; H. F. Leibecki; J. M. Bozek

    1980-01-01

    The data analysis of cycles to failure of silver-zinc electrochemical cells with competing failure modes is presented. The test ran 129 cells through charge-discharge cycles until failure; preliminary data analysis consisted of response surface estimate of life. Batteries fail through low voltage condition and an internal shorting condition; a competing failure modes analysis was made using maximum likelihood estimation for

  14. Advanced membranes for alkaline primary and rechargeable alkaline cells with zinc anodes

    Microsoft Academic Search

    Harlan Lewis; Patricia Jackson; Alvin Salkind; Thomas Danko; Roger Bell

    2001-01-01

    Several advanced cellulosic and radiation grafted polypropylene membrane materials are currently under evaluation in the laboratories at Navsea Crane and Rutgers University, for application to alkaline primary and rechargeable cell chemistries which employ zinc as the anode material. A portion of these tests involve model cell evaluations of cellulosic membranes for silver migration rates through the membranes as a function

  15. Solar cell anomaly detection method and apparatus

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

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

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

    SciTech Connect

    Gianotti, A.J.; Clark, D.T.; Dash, J. (Portland State Univ., OR (USA))

    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.

  17. Indium oxide/n-silicon heterojunction solar cells

    DOEpatents

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

    1982-12-28

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

  18. Cannabidiol affects the expression of genes involved in zinc homeostasis in BV-2 microglial cells.

    PubMed

    Juknat, Ana; Rimmerman, Neta; Levy, Rivka; Vogel, Zvi; Kozela, Ewa

    2012-11-01

    Cannabidiol (CBD) has been shown to exhibit anti-inflammatory, antioxidant and neuroprotective properties. Unlike ?(9)-tetrahydrocannabinol (THC), CBD is devoid of psychotropic effects and has very low affinity for both cannabinoid receptors, CB(1) and CB(2). We have previously reported that CBD and THC have different effects on anti-inflammatory pathways in lipopolysaccharide-stimulated BV-2 microglial cells, in a CB(1)/CB(2) independent manner. Moreover, CBD treatment of BV-2 cells, was found to induce a robust change in the expression of genes related to oxidative stress, glutathione deprivation and inflammation. Many of these genes were shown to be controlled by Nrf2 and ATF4 transcription factors. Using the Illumina MouseRef-8 BeadChip platform, DAVID Bioinformatics and Ingenuity Pathway Analysis, we identified functional sets of genes and networks affected by CBD. A subset of genes was found to be regulated by the metal responsive element (MRE)-binding transcription factor-1 (MTF-1) and is shown to be related to zinc homeostasis. We found that CBD upregulates the expression of the mRNAs for metallothionein 2 (Mt2), N-myc-downstream regulated gene 1 and matrix metalloproteinase 23 as well as of the zinc transporters ZnT1/Slc30a1 and Zip4/Slc39a4 but downregulates the expression of the mRNA for the zinc transporter Zip10/Slc39a10 as well as for the zinc finger protein 472. Among these genes, ZnT1, Mt2 and the zinc transporters ZIPs are known to function together to control the intracellular zinc concentration. These results show that CBD, but much less so THC, affects the expression of genes involved in zinc homeostasis and suggest that the regulation of zinc levels could have an important role through which CBD may exert its antioxidant and anti-inflammatory effects. PMID:22178458

  19. Induction of type 1 interferon receptor by zinc in U937 cells.

    PubMed

    Nagamine, Takeaki; Nakajima, Kastuyuki; Takada, Hisashi; Sekine, Yoshitaka; Suzuki, Kazuhiro

    2009-06-01

    This study aims to determine whether zinc enhances interferon (IFN)-alpha activity in U937 cells. Type 1 IFN2 receptor (IFNAR2) protein in U937 cells was measured by flow cytometry. After 24h of exposure to zinc chloride or polaprezinc (a chelate of zinc and L-carnosine) at concentrations ranging from 50 to 200 microM, histograms showing anti-IFNAR2 antibody-positive cells shifted to a higher FITC intensity. Zinc chloride and polaprezinc increased IFNAR2 mRNA levels approximately 30% and 40%, respectively, compared to the control. L-carnosine alone did not alter IFNAR2 mRNA or protein levels. Cellular levels of 2'-5' oligoadenylate synthetases (OAS) were markedly increased by IFN-alpha, and the increase was significantly accelerated by polaprezinc. However, polaprezinc alone did not increase 2'-5'OAS levels. The finding suggests that zinc, especially polaprezinc, enhances the expression of INFAR2 in U937 cells, thereby inducing production of the anti-viral protein 2'-5'OAS. PMID:19362011

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

    Microsoft Academic Search

    M. D. Lammert; R. J. Schwartz

    1977-01-01

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

  1. Solar Cell Efficiency Tables (Version 33)

    Microsoft Academic Search

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

    2009-01-01

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

  2. Multi-junction solar cell designs

    Microsoft Academic Search

    Mahieddine Emziane; Adam Sleiman

    2011-01-01

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

  3. Germanium-on-glass solar cells

    Microsoft Academic Search

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

    2011-01-01

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

  4. Space solar cell research: Problems and potential

    Microsoft Academic Search

    D. J. Flood

    1986-01-01

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

  5. Space solar cell research - Problems and potential

    Microsoft Academic Search

    Dennis J. Flood

    1986-01-01

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

  6. Radiation degradation of solar cell arrays

    NASA Technical Reports Server (NTRS)

    Hill, C. W.

    1975-01-01

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

  7. 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.

  8. Transparent superstrate terrestrial solar cell module

    NASA Technical Reports Server (NTRS)

    1977-01-01

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

  9. Large area, low cost space solar cells

    NASA Technical Reports Server (NTRS)

    Kukulka, J.; Iles, P. A.

    1982-01-01

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

  10. High-efficiency thin silicon solar cells

    Microsoft Academic Search

    J. Michel; E. Fabre; M. Mautref

    1976-01-01

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

  11. Large area, low cost space solar cells

    SciTech Connect

    Kukulka, J.; Iles, P.A.

    1982-09-01

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

  12. Mars optimized solar cell technology (MOST)

    Microsoft Academic Search

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

    2008-01-01

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

  13. Solar Cells With Multiple Small Junctions

    NASA Technical Reports Server (NTRS)

    Daud, T.; Koliwad, K. M.

    1985-01-01

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

  14. Solar cell anomaly detection method and apparatus

    Microsoft Academic Search

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

    1981-01-01

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

  15. COLLOIDAL SEMICONDUCTOR NANOCRYSTALS BASED SOLAR CELLS

    E-print Network

    Tessler, Nir

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

  16. Ultrathin silicon solar cell for space application

    Microsoft Academic Search

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

    1982-01-01

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

  17. 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.

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

    E-print Network

    Zhou, Weidong

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

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

    Microsoft Academic Search

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

    2003-01-01

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

  20. Space solar cells: High efficiency and radiation damage

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

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

  1. III-V material solar cells for space application

    Microsoft Academic Search

    T. V. Torchynska; G. P. Polupan

    2002-01-01

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

  2. Colloidal cluster phases and solar cells 

    E-print Network

    Mailer, Alastair George

    2012-11-28

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

  3. EE580 Solar Cells Todd J. Kaiser

    E-print Network

    Kaiser, Todd J.

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

  4. Heavily doped polysilicon-contact solar cells

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

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

  5. Inexpensive silicon sheets for solar cells

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

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

  6. Selective laser patterning in organic solar cells

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

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

  7. Texturization of multicrystalline silicon solar cells

    E-print Network

    Li, Dai-Yin

    2010-01-01

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

  8. Solar cell array design handbook. Volume II

    Microsoft Academic Search

    Rauschenbach

    1976-01-01

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

  9. Solar cell array design handbook, volume 1

    NASA Technical Reports Server (NTRS)

    Rauschenbach, H. S.

    1976-01-01

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

  10. 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.

  11. 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.

  12. 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.

  13. A space solar cell bonding robot

    Microsoft Academic Search

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

    2006-01-01

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

  14. Limiting efficiency of silicon solar cells

    Microsoft Academic Search

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

    1984-01-01

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

  15. 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.

  16. Dye sensitized solar cells on paper substrates

    Microsoft Academic Search

    Bo Wang; Lei L. Kerr

    2011-01-01

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

  17. Amorphous thin-film solar cells

    Microsoft Academic Search

    W. Krühler

    1991-01-01

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

  18. Schottky solar cells on thin epitaxial silicon

    Microsoft Academic Search

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

    1976-01-01

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

  19. Nanowire dye-sensitized solar cells

    Microsoft Academic Search

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

    2005-01-01

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

  20. Magnetoresistance in bulk heterojunction solar cells

    Microsoft Academic Search

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

    2008-01-01

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